Reassessing the minimum two-year follow-up standard after lumbar decompression surgery: a 2-months follow-up seems to be an acceptable minimum

BACKGROUND CONTEXT

Academic orthopedic journals and specialty societies emphasize the importance of two-year follow-up for patient-reported outcome measures (PROMS) after spine surgery, but there are limited data evaluating the appropriate length of follow-up.

PURPOSE

To determine whether PROMs, as measured by the Oswestry Disability Index (ODI), would change significantly after 2-months postoperatively after lumbar decompression surgery for disc herniation or spinal stenosis.

STUDY DESIGN

Retrospective analysis of prospectively and consecutively enrolled patients undergoing lumbar decompression surgery between 2020 and 2021 from a single surgeon spine registry.

PATIENT SAMPLE

One hundred sixty-nine patients.

OUTCOME MEASURES

ODI, achievement of minimum clinically important difference (MCID), revisions.

METHODS

Patients without a preoperative baseline score were excluded. Completion of the ODI questionnaire was assessed at the follow-up points. The median ODI was compared at time baseline, 2-month, 1-year and 2-year follow-up. Risk of reoperation was assessed with receiver operating characteristic (ROC) analysis to identify at-risk ODI thresholds of requiring reoperation.

RESULTS

Median ODI significantly improved at all time points compared to baseline (median baseline ODI: 40; 2-month ODI: 16, p=.001; 1-year ODI: 11.1, p=.001; 2-year ODI: 8, p=.001). Post-hoc analysis demonstrated no difference between 2-months, 1-year and 2-year postoperative ODI (p=.9, p=.468, p=.606). The MCID was met in 87.9% of patients at 2 months, 80.7% at 1 year, and 87.3% at 2 years postoperatively. Twelve patients (7.7%) underwent revision surgery between 2 months and 2 years after the index surgery (median time to revision: 5.6 months). ROC curve analysis demonstrated that an ODI score ≥24 points at 2-months yielded a sensitivity of 85.7% and a specificity of 71.8% for predicting revision after lumbar decompression (AUC=0.758; 95% CI: 0.613-0.903). The Youden optimal threshold value of ≥24 points at 2-month postop ODI yielded an odd ratio (OR) for revision of 15.3 (CI: 1.8-131.8; p=.004). The positive predictive value (PPV) and negative predictive value (NPV) were 15.4% and 98.8%, respectively.

CONCLUSION

Two-year clinical follow-up may not be necessary for future peer-reviewed lumbar decompression surgery studies given that ODI plateaus at 8 weeks. Patients with a score ≥24 points at 2-months postoperatively have a higher risk of requiring a second surgery within the first two years and warrant continued follow-up.

Does Bone Morphogenetic Protein Use Reduce Pseudarthrosis Rates in Single-Level Transforaminal Lumbar Interbody Fusion Surgeries?

BACKGROUND

Recombinant human bone morphogenetic protein 2 (rhBMP-2, or BMP for short) is a popular biological product used in spine surgeries to promote fusion and avoid the morbidity associated with iliac crest autograft. BMP's effect on pseudarthrosis in transforaminal lumbar interbody fusion (TLIF) remains unknown.

OBJECTIVE

To assess the rates of pseudarthrosis in single-level TLIF with and without concurrent use of BMP.

METHODS

This was a retrospective cohort study conducted at a single academic institution. Adults undergoing primary single-level TLIF with a minimum of 1 year of clinical and radiographic follow-up were included. BMP use was determined by operative notes at index surgery. Non-BMP cases with iliac crest bone graft were excluded. Pseudarthrosis was determined using radiographic and clinical evaluation. Bivariate differences between groups were assessed by independent t test and χ 2 analyses, and perioperative characteristics were analyzed by multiple logistic regression.

RESULTS

One hundred forty-eight single-level TLIF patients were included. The mean age was 59.3 years, and 52.0% were women. There were no demographic differences between patients who received BMP and those who did not. Pseudarthrosis rates in patients treated with BMP were 6.2% vs 7.5% in the no BMP group (P = 0.756). There was no difference in reoperation for pseudarthrosis between patients who received BMP (3.7%) vs those who did not receive BMP (7.5%, P = 0.314). Patients who underwent revision surgery for pseudarthrosis more commonly had diabetes with end-organ damage (revised 37.5% vs not revised 1.4%, P < 0.001). Multiple logistic regression analysis demonstrated no reduction in reoperation for pseudarthrosis related to BMP use (OR 0.2, 95% CI 0.1-3.7, P = 0.269). Diabetes with end-organ damage (OR 112.6,95% CI 5.7-2225.8, P = 0.002) increased the risk of reoperation for pseudarthrosis.

CONCLUSIONS

BMP use did not reduce the rate of pseudarthrosis or the number of reoperations for pseudarthrosis in single-level TLIFs. Diabetes with end-organ damage was a significant risk factor for pseudarthrosis.

CLINICAL RELEVANCE

BMP is frequently used "off-label" in transforaminal lumbar interbody fusion; however, little data exists to demonstrate its safety and efficacy in this procedure.

LEVEL OF EVIDENCE: 3

Single-Position Prone Lateral Lumbar Interbody Fusion Increases Operative Efficiency and Maintains Safety in Revision Lumbar Spinal Fusion

STUDY DESIGN

Multi-centre retrospective cohort study.

OBJECTIVE

To evaluate the feasibility and safety of the single-position prone lateral lumbar interbody fusion (LLIF) technique for revision lumbar fusion surgery.

BACKGROUND CONTEXT

Prone LLIF (P-LLIF) is a novel technique allowing for placement of a lateral interbody in the prone position and allowing posterior decompression and revision of posterior instrumentation without patient repositioning. This study examines perioperative outcomes and complications of single position P-LLIF against traditional Lateral LLIF (L-LLIF) technique with patient repositioning.

METHOD

A multi-centre retrospective cohort study involving patients undergoing 1 to 4 level LLIF surgery was performed at 4 institutions in the US and Australia. Patients were included if their surgery was performed via either: P-LLIF with revision posterior fusion; or L-LLIF with repositioning to prone. Demographics, perioperative outcomes, complications, and radiological outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at P <0.05.

RESULTS

101 patients undergoing revision LLIF surgery were included, of which 43 had P-LLIF and 58 had L-LLIF. Age, BMI and CCI were similar between groups. The number of posterior levels fused (2.21 P-LLIF vs. 2.66 L-LLIF, P =0.469) and number of LLIF levels (1.35 vs. 1.39, P =0.668) was similar between groups.Operative time was significantly less in the P-LLIF group (151 vs. 206 min, P =0.004). EBL was similar between groups (150mL P-LLIF vs. 182mL L-LLIF, P =0.31) and there was a trend toward reduced length of stay in the P-LLIF group (2.7 vs. 3.3d, P =0.09). No significant difference was demonstrated in complications between groups. Radiographic analysis demonstrated no significant differences in preoperative or postoperative sagittal alignment measurements.

CONCLUSION

P-LLIF significantly improves operative efficiency when compared to L-LLIF for revision lumbar fusion. No increase in complications was demonstrated by P-LLIF or trade-offs in sagittal alignment restoration.

LEVEL OF EVIDENCE

Level 4.

Lateral lumbar interbody fusion at L4-L5 has a low rate of complications in appropriately selected patients when using a standardized surgical technique

Aims

The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.

Methods

This was a multicentre retrospective study involving consecutively enrolled patients who underwent L4-L5 LLIF by seven surgeons at seven institutions in three countries over a five-year period. The demographic details of the patients and the details of the surgery, reoperations and complications, including femoral and non-femoral neuropraxia, thigh pain, weakness of hip flexion, and abdominal complications, were analyzed. Neurological and psoas-related complications attributed to LLIF or posterior instrumentation and persistent symptoms were recorded at one year postoperatively.

Results

A total of 517 patients were included in the study. Their mean age was 65.0 years (SD 10.3) and their mean BMI was 29.2 kg/m2 (SD 5.5). A mean of 1.2 levels (SD 0.6) were fused with LLIF, and a mean of 1.6 (SD 0.9) posterior levels were fused. Femoral neuropraxia occurred in six patients (1.2%), of which four (0.8%) were LLIF-related and two (0.4%) had persistent symptoms one year postoperatively. Non-femoral neuropraxia occurred in nine patients (1.8%), one (0.2%) was LLIF-related and five (1.0%) were persistent at one year. All LLIF-related neuropraxias resolved by one year. A total of 32 patients (6.2%) had thigh pain, 31 (6.0%) were LLIF-related and three (0.6%) were persistent at one year. Weakness of hip flexion occurred in 14 patients (2.7%), of which eight (1.6%) were LLIF-related and three (0.6%) were persistent at one year. No patients had bowel injury, three (0.6%) had an intraoperative vascular injury (not LLIF-related), and five (1.0%) had ileus. Reoperations occurred in five patients (1.0%) within 30 days, 37 (7.2%) within 90 days, and 41 (7.9%) within one year postoperatively.

Conclusion

LLIF involving the L4-L5 disc level has a low rate of persistent neurological, psoas-related, and abdominal complications in patients with the appropriate indications and using a standardized surgical technique.

Comparative Analysis of Inpatient Opioid Consumption Between Different Surgical Approaches Following Single Level Lumbar Spinal Fusion Surgery

STUDY DESIGN

Single-center retrospective cohort study.

OBJECTIVES

To evaluate inpatient MME administration associated with different lumbar spinal fusion surgeries.

METHODS

Patients ≥18 years of age with a diagnosis of Grade I or II spondylolisthesis, stenosis, degenerative disc disease or pars defect who underwent one-level Transforaminal Lumbar Interbody Fusion (TLIF) or one-level Anterior Lumbar Interbody Fusion (ALIF) or Lateral Lumbar Interbody Fusion (LLIF) through traditional MIS, anterior-posterior position or single position approaches between L2-S1. Outcome measures included patient demographics, surgical procedure and approach, perioperative clinical characteristics, incidence of ileus and inpatient MME. Statistical analysis included one-way ANOVA with a post-hoc Tukey Test and Kruskal-Wallis Test with post-hoc Mann-Whitney test. MME was calculated as per the Centers for Medicare and Medicaid Services and previous literature. Significance set at P < .05.

RESULTS

Mean age differed significantly between MIS TLIF (55.6 ± 12.5 years) and all other groups (Open TLIF 57.1 ± 12.5, SP ALIF/LLIF 57.9 ± 9.9, TP ALIF/LLIF 50.9 ± 12.7, Open ALIF/LLIF 58.4 ± 15.5). MIS TLIF had the shortest LOS compared to all groups except SP ALIF/LLIF. Total MME was significantly different between MIS TLIF and Open ALIF/LLIF (172.5 MME vs 261.1 MME, P = .044) as well as MIS TLIF and TP ALIF/LLIF (172.5 MME vs 245.4 MME, P = .009). There were no significant differences in MME/hour and incidence of ileus between all groups.

CONCLUSION

Patients undergoing MIS TLIF had lower inpatient opioid intake compared to TP and SP ALIF/LLIF, as well as shorter LOS compared to all groups except SP ALIF/LLIF. Thus, it appears that the advantages of minimally invasive surgery are seen in minimally invasive TLIFs.

Multidisciplinary conference for complex surgery leads to improved quality and safety

INTRODUCTION

Complex surgery for adult spinal deformity has high rates of complications, reoperations, and readmissions. Preoperative discussions of high-risk operative spine patients at a multidisciplinary conference may contribute to decreased rates of these adverse outcomes through appropriate patient selection and surgical plan optimization. With this goal, we implemented a high-risk case conference involving orthopedic and neurosurgery spine, anesthesia, intraoperative monitoring neurology, and neurological intensive care.

METHODS

Included in this retrospective review were patients ≥ 18 years old meeting one of the following high-risk criteria: 8 + levels fused, osteoporosis with 4 + levels fused, three column osteotomy, anterior revision of the same lumbar level, or planned significant correction for severe myelopathy, scoliosis (> 75˚), or kyphosis (> 75˚). Patients were categorized as Before Conference (BC): surgery before 2/19/2019 or After Conference (AC): surgery after 2/19/2019. Outcome measures include intraoperative and postoperative complications, readmissions, and reoperations.

RESULTS

263 patients were included (96 AC, 167 BC). AC was older than BC (60.0 vs 54.6, p = 0.025) and had lower BMI (27.1 vs 28.9, p = 0.047), but had similar CCI (3.2 vs 2.9 p = 0.312), and ASA Classification (2.5 vs 2.5, p = 0.790). Surgical characteristics, including levels fused (10.6 vs 10.7, p = 0.839), levels decompressed (1.29 vs 1.25, p = 0.863), 3 column osteotomies (10.4% vs 18.6%, p = 0.080), anterior column release (9.4% vs 12.6%, p = 0.432), and revision cases (53.1% vs 52.4%, p = 0.911) were similar between AC and BC. AC had lower EBL (1.1 vs 1.9L, p < 0.001) and fewer total intraoperative complications (16.7% vs 34.1%, p = 0.002), including fewer dural tears (4.2% vs 12.6%, p = 0.025), delayed extubations (8.3% vs 22.8%%, p = 0.003), and massive blood loss (4.2% vs 13.2%, p = 0.018). Length of stay (LOS) was similar between groups (7.2 vs 8.2 days, 0.251). AC had a lower incidence of deep surgical site infections (SSI, 1.0% vs 6.6%, p = 0.038), but a higher rate of hypotension requiring vasopressor therapy (18.8% vs 4.8%, p < 0.001). Other postoperative complications were similar between groups. AC had lower rates of reoperation at 30 (2.1% vs 8.4%, p = 0.040) and 90 days (3.1 vs 12.0%, p = 0.014) and lower readmission rates at 30 (3.1% vs 10.2%, p = 0.038) and 90 days (6.3 vs 15.0%, p = 0.035). On logistic regression, AC patients had higher odds of hypotension requiring vasopressor therapy and lower odds of delayed extubation, intraoperative RBC, and intraoperative salvage blood.

CONCLUSIONS

Following implementation of a multidisciplinary high-risk case conference, 30- and 90-day reoperation and readmission rates, intraoperative complications, and postoperative deep SSIs decreased. Hypotensive events requiring vasopressors increased, but did not result in longer LOS or greater readmissions. These associations suggest a multidisciplinary conference may help improve quality and safety for high-risk spine patients. particularly through minimizing complications and optimizing outcomes in complex spine surgery.

The Impact of Global Spinal Alignment on Standing Spinopelvic Alignment Change After Total Hip Arthroplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The interactions between hip osteoarthritis (OA) and spinal malalignment are poorly understood. The purpose of this study was to assess the influence of total hip arthroplasty (THA) on standing spinopelvic alignment.

METHODS

In this retrospective cohort study, patients undergoing THA for OA with pre-and postoperative full-body radiographs were included. Standing spinopelvic parameters were measured. Contralateral hip was graded on the Kellgren-Lawrence scale. Pre-and postoperative alignment parameters were compared by paired t-test. The severity of preoperative thoracolumbar deformity was measured using TPA. Linear regression was performed to assess the impact of preoperative TPA and changes in spinal alignment. Patients were separated into low and high TPA (<20 or >/=20 deg) and change in parameters were compared between groups by t-test. Similarly, the influence of K-L grade, age, and PI were also tested.

RESULTS

95 patients were included (mean age 58.6 yrs, BMI 28.7 kg/m2, 48.2% F). Follow-up radiographs were performed at mean 220 days. Overall, the following significant changes were found from pre-to postoperative: SPT (14.2 vs. 16.1, P = 0.021), CL (-8.9 vs. -5.3, P = .001), TS-CL (18.2 vs. 20.5, P = .037) and SVA (42.6 vs. 32.1, P = .004). Preoperative TPA was significantly associated with the change in PI-LL, SVA, and TPA. High TPA patients significantly decreased SVA more than low TPA patients. There was no significant impact of contralateral hip OA, PI, or age on change in alignment parameters.

CONCLUSION

Spinopelvic alignment changes after THA, evident by a reduction in SVA. Preoperative spinal sagittal deformity impacts this change. Level of evidence: III.

Creating Consensus in the Definition of Spinopelvic Mobility

INTRODUCTION

The term "spinopelvic mobility" is most often applied to motion within the spinopelvic segment. It has also been used to describe changes in pelvic tilt between various functional positions, which is influenced by motion at the hip, knee, ankle and spinopelvic segment. In the interest of establishing a consistent language for spinopelvic mobility, we sought to clarify and simplify its definition to create consensus, improve communication, and increase consistency with research into the hip-spine relationship.

METHODS

A literature search was performed using the Medline (PubMed) library to identify all existing articles pertaining to spinopelvic mobility. We reported on the varying definitions of spinopelvic mobility including how different radiographic imaging techniques are used to define mobility.

RESULTS

The search term "spinopelvic mobility" returned a total of 72 articles. The frequency and context for the varying definitions of mobility were reported. 41 papers used standing and upright relaxed-seated radiographs without the use of extreme positioning, and 17 papers discussed the use of extreme positioning to define spinopelvic mobility.

DISCUSSION

Our review suggests that the definitions of spinopelvic mobility is not consistent in the majority of published literature. We suggest descriptions of spinopelvic mobility independently consider spinal motion, hip motion, and pelvic position, while recognizing and describing their interdependence.

Lateral lumbar interbody fusion - clinical outcomes, fusion rates and complications with recombinant human bone morphogenetic protein-2

BACKGROUND

The authors report an Australian experience of lateral lumbar interbody fusion (LLIF) with respect to clinical outcomes, fusion rates, and complications, with recombinant human bone morphogenetic protein-2 (rhBMP-2) and other graft materials.

METHODS

Retrospective cohort study of LLIF patients 2011-2021. LLIFs performed lateral decubitus by four experienced surgeons past their learning curve. Graft materials classified rhBMP-2 or non-rhBMP-2. Patient-reported outcomes assessed by VAS, ODI, and SF-12 preoperatively and postoperatively. Fusion rates assessed by CT postoperatively at 6 and 12 months. Complications classified minor or major. Clinical outcomes and complications analysed and compared between rhBMP-2 and non-rhBMP-2 groups.

RESULTS

A cohort of 343 patients underwent 437 levels of LLIF. Mean age 67 ± 11 years (range 29-89) with a female preponderance (65%). Mean BMI 29kg/m2 (18-56). Most common operated levels L3/4 (36%) and L4/5 (35%). VAS, ODI and SF-12 improved significantly from baseline. Total complication rate 15% (53/343) with minor 11% (39/343) and major 4% (14/343). Ten patients returned to OR (2-wound infection, 8-further instrumentation and decompression). Most patients (264, 77%) received rhBMP-2, the remainder a non-rhBMP-2 graft material. No significant differences between groups at baseline. No increase in minor or major complications in the rhBMP-2 group compared to the non-rhBMP-2 group respectively; (10.6% vs 13.9% [p = 0.42], 2.7% vs 8.9% [p < 0.01]). Fusion rates significantly higher in the rhBMP-2 group at 6 and 12 months (63% vs 40%, [p < 0.01], 92% vs 80%, [p < 0.02]).

CONCLUSION

LLIF is a safe and efficacious procedure. rhBMP-2 in LLIF produced earlier and higher fusion rates compared to available non-rhBMP-2 graft substitutes.

Minimally Invasive Transforaminal Lumbar Interbody Fusion with Expandable Cages

Background

Minimally invasive surgical transforaminal lumbar interbody fusion (MIS-TLIF) is an increasingly common procedure for the treatment of lumbar degenerative pathologies. The MIS-TLIF technique often results in less soft-tissue injury compared with the open TLIF technique, reducing postoperative pain and recovery time1-3. However, the narrow surgical aperture of this minimally invasive technique has increased the difficulty of interbody cage placement. Expandable cages were designed to improve ease of insertion, improve visualization around the cage on insertion, reduce neurological retraction and injury by passing the nerve root with the implant in a collapsed state, and enable better disc-height and lordosis restoration on expansion4.

Description

This procedure is performed with the patient under general anesthesia and in a prone position. The appropriate spinal level is identified with use of fluoroscopy, and bilateral paramidline approaches are made utilizing the Wiltse intermuscular approach. Pedicle screws are placed bilaterally. A pedicle-based retractor or tubular retractor is passed along the Wiltse plane, and bilateral inferior facetectomies are performed. A foraminotomy is performed, including a superior facetectomy on the side with compression of the exiting nerve root. A thorough discectomy with end-plate preparation is performed. The disc space is sized with use of trial components. The cage is then implanted with a pre-expansion height less than the trialed height and is expanded under fluoroscopy. After expansion, the cage is backfilled with allograft and local autograft. Finally, the rods are contoured and reduced bilaterally, followed by closure in a multilayered approach.

Alternatives

Nonoperative alternatives to the minimally invasive TLIF technique include physical therapy or epidural corticosteroid injections. When surgical intervention is indicated, there are several approaches that can be utilized during lumbar interbody fusion, including the posterior, direct lateral, anterior, or oblique approaches5.

Rationale

Expandable cages are designed to be inserted in a collapsed configuration and expanded once placed into the interbody space. This design offers numerous potential advantages over static alternatives. The low-profile, expandable cages require less impaction during placement, minimizing iatrogenic end-plate damage. Additionally, expandable cages require less thecal and nerve-root retraction and provide a larger surface footprint once expanded.

Expected Outcomes

The MIS-TLIF technique has been shown to significantly reduce back pain, leg pain, and disability, and to significantly increase function, with most improvements observed after 12 months postoperatively. Patients may experience a 51% and 39% reduction in visual analogue pain scores and Oswestry Disability Index scores, respectively6. The results for expandable cages compared with traditional static cages in TLIF surgery require further study.

Important Tips

The technique utilized during insertion and placement of interbody cages plays an important role in cage subsidence. To reduce the risk of cage subsidence, cages should be placed level with the end plate and in contact with the apophyseal ring anteriorly. Additionally, caution should be taken when expanding the cage to ensure that the cage is not overexpanded, which may also increase the risk of mechanical failure and intraoperative subsidence.It is critical to understand the flexibility of the disc space and the osseous quality of the patient in order to know how much expansion may be applied through the cage without subsidence.If bullet-type cages are utilized, the tip of the cage should cross midline of the vertebral body to avoid generating iatrogenic scoliosis.Spine bone density should be investigated preoperatively in at-risk patients in order to identify osteoporotic patients, who are at greater risk for subsidence and instrumentation failure.Although advances in device technology are welcomed, surgeons should maintain a strong focus on technique to reduce complications and improve clinical outcomes when utilizing expandable cages.

Acronyms & Abbreviations

TLIF = transforaminal lumbar interbody fusionMIS = minimally invasive surgeryALIF = anterior lumbar interbody fusionMRI = magnetic resonance imagingCT = computed tomographyPEEK = polyetheretherketoneAP = anterioposteriorEMG = electromyographyDVT = deep vein thrombosisPE = pulmonary embolusODI = Oswestry Disability IndexEXP = expandable.

Evaluation of Health-related Quality of Life Improvement in Patients Undergoing Cervical Versus Shoulder Surgery

STUDY DESIGN

Retrospective analysis of outcomes in cervical spine and shoulder arthroscopy patients.

OBJECTIVE

The objective of this study is to assess differential improvements in health-related quality of life for cervical spine surgery compared with shoulder surgery.

SUMMARY OF BACKGROUND DATA

An understanding of outcome differences between different types of orthopedic surgeries is helpful in counseling patients about expected postoperative recovery. This study compares outcomes in patients undergoing cervical spine surgery with arthroscopic shoulder surgery using computer-adaptive Patient-reported Outcome Information System scores.

MATERIALS AND METHODS

Patients undergoing cervical spine surgery (1-level or 2-level anterior cervical discectomy and fusion, cervical disc replacement) or arthroscopic shoulder surgery (rotator cuff repair±biceps tenodesis) were grouped. Patient-reported Outcome Information System scores of physical function, pain interference, and pain intensity at baseline and at 3, 6, and 12 months were compared using paired t tests.

RESULTS

Cervical spine (n=127) and shoulder (n=91) groups were similar in sex (25.8% vs. 41.8% female, P =0.731) but differed in age (51.6±11.6 vs. 58.60±11.2, P <0.05), operative time (148.3±68.6 vs. 75.9±26.9 min, P <0.05), American Society of Anesthesiologists (ASAs) (2.3±0.6 vs. 2.0±0.5, P =0.001), smoking status (15.7% vs. 4.4%, P =0.008), and length of stay (1.1±1.0 vs. 0.3±0.1, P =0.000). Spine patients had worse physical function (36.9 ±12.6 vs. 49.4±8.6, P <0.05) and greater pain interference (67.0±13.6 vs. 61.7±4.8, P =0.001) at baseline. Significant improvements were seen in all domains by 3 months for both groups, except for physical function after shoulder surgery. Spine patients had greater physical function improvements at all timepoints (3.33 vs. -0.43, P =0.003; 4.81 vs. 0.08, P =0.001; 6.5 vs. -5.24, P =<0.05). Conversely, shoulder surgery patients showed better 6-month improvement in pain intensity over spine patients (-8.86 vs. -4.46, P =0.001), but this difference resolved by 12 months.

CONCLUSIONS

Cervical spine patients had greater relative early improvement in physical function compared with shoulder patients, whereas pain interference and intensity did not significantly differ between the 2 groups after surgery. This will help in counseling patients about relative difference in recovery and improvement between the 2 surgery types.

LEVEL OF EVIDENCE

III.

Effect of Pelvic Sagittal Tilt and Axial Rotation on Functional Acetabular Orientation

Accurate and reproducible acetabular component positioning is among the most important technical factors affecting outcomes of total hip arthroplasty. Although several studies have investigated the influence of pelvic tilt and obliquity on functional acetabular anteversion, the effect of pelvic axial rotation has not yet been established. We analyzed a generic simulated pelvis created using preoperative full-body standing and sitting radiographs. A virtual acetabulum was placed in 144 different scenarios of acetabular anteversion and abduction angles. In each scenario, the effects of pelvic tilt and pelvic axial rotation on different combinations of acetabular orientations were assessed. The change in acetabular anteversion was 0.75° for each 1° of pelvic tilt and was most linear in abduction angles of 40°±45°. The change in acetabular anteversion was 0.8° for each 1° of pelvic axial rotation. Surgeons may consider adjusting acetabular anteversion in fixed axial pelvic deformities when the degree of deformity affects functional acetabular positioning, assessed from preoperative standing and sitting weight-bearing radiographs. [Orthopedics. 2023;46(1):e27-e30.].

Lateral decubitus single position anterior posterior surgery improves operative efficiency, improves perioperative outcomes, and maintains radiological outcomes comparable with traditional anterior posterior fusion at minimum 2-year follow-up

BACKGROUND CONTEXT

The advantages of Lateral Single Position surgery (LSPS) in the perioperative period has previously been demonstrated, however 2-year postoperative outcomes of this novel technique have not yet been compared to circumferential anterior-posterior fusion (FLIP) at 2-years postoperatively.

PURPOSE

Evaluate the safety and efficacy of LSPS versus gold-standard FLIP STUDY DESIGN/SETTING: Multi-center retrospective cohort review.

PATIENT SAMPLE

Four hundred forty- two patients undergoing lumbar fusion via LSPS or FLIP OUTCOME MEASURES: Levels fused, operative time, estimated blood loss, perioperative complications, and reasons for reoperation at 30-days, 90-days, 1-year, and 2-years. Radiographic outcomes included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, and segmental lumbar lordosis.

METHODS

Patients were grouped as LSPS if anterior and posterior portions of the procedure were performed in the lateral decubitus position, and FLIP if patients were repositioned from supine or lateral to prone position for the posterior portion of the procedure under the same anesthetic. Groups were compared in terms of demographics, intraoperative, perioperative and radiological outcomes, complications and reoperations up to 2-years follow-up. Measures were compared using independent samples or paired t-tests and chi-squared analyses with significance set at p<.05.

RESULTS

Four hundred forty- two pts met inclusion, including 352 LSPS and 90 FLIP pts. Significant differences were noted in age (62.4 vs 56.9; p≤.001) and smoking status (7% vs 16%; p=.023) between the LSPS and FLIP groups. LSPS demonstrated significantly lower Op time (97.7min vs 297.0 min; p<.001), fluoro dose (36.5mGy vs 78.8mGy; p<.001), EBL (88.8mL vs 270.0mL; p<.001), and LOS (1.91 days vs 3.61 days; p<.001) compared to FLIP. LSPS also demonstrated significantly fewer post-op complications than FLIP (21.9%vs 34.4%; p=.013), specifically regarding rates of ileus (0.0% vs 5.6%; p<.001). No differences in reoperation were noted at 30-day (1.7%LSPS vs 4.4%FLIP, p=.125), 90-day (5.1%LSPS vs 5.6%FLIP, p=.795) or 2-year follow-up (9.7%LSPS vs 12.2% FLIP; p=.441). LSPS group had a significantly lower preoperative PI-LL (4.1° LSPS vs 8.6°FLIP, p=.018), and a significantly greater postoperative LL (56.6° vs 51.8°, p = .006). No significant differences were noted in rates of fusion (94.3% LSPS vs 97.8% FLIP; p=.266) or subsidence (6.9% LSPS vs 12.2% FLIP; p=.260).

CONCLUSIONS

LSPS and circumferential fusions have similar outcomes at 2-years post-operatively, while reducing perioperative complications, improving perioperative efficiency and safety.

Single-position circumferential lumbar spinal fusion: an overview of terminology, concepts, rationale and the current evidence base

PURPOSE

To provide definitions and a conceptual framework for single position surgery (SPS) applied to circumferential fusion of the lumbar spine.

METHODS

Narrative literature review and experts' opinion.

RESULTS

Two major limitations of lateral lumbar interbody fusion (LLIF) have been (a) a perceived need to reposition the patient to the prone position for posterior fixation, and (b) the lack of a robust solution for fusion at the L5/S1 level. Recently, two strategies for performing single-position circumferential lumbar spinal fusion have been described. The combination of anterior lumbar interbody fusion (ALIF) in the lateral decubitus position (LALIF), LLIF and percutaneous pedicle screw fixation (pPSF) in the lateral decubitus position is known as lateral single-position surgery (LSPS). Prone LLIF (PLLIF) involves transpsoas LLIF done in the prone position that is more familiar for surgeons to then implant pedicle screw fixation. This can be referred to as prone single-position surgery (PSPS). In this review, we describe the evolution of and rationale for single-position spinal surgery. Pertinent studies validating LSPS and PSPS are reviewed and future questions regarding the future of these techniques are posed. Lastly, we present an algorithm for single-position surgery that describes the utility of LALIF, LLIF and PLLIF in the treatment of patients requiring AP lumbar fusions.

CONCLUSIONS

Single position surgery in circumferential fusion of the lumbar spine includes posterior fixation in association with any of the following: lateral position LLIF, prone position LLIF, lateral position ALIF, and their combination (lateral position LLIF+ALIF). Preliminary studies have validated these methods.

Assessing Postoperative Pseudarthrosis in Anterior Cervical Discectomy and Fusion (ACDF) on Dynamic Radiographs Using Novel Angular Measurements

STUDY DESIGN

A retrospective review of operative patients at a single institution.

OBJECTIVE

The aim was to validate a novel method of detecting pseudarthrosis on dynamic radiographs.

SUMMARY OF BACKGROUND DATA

A common complication after anterior cervical discectomy and fusion is pseudarthrosis. A previously published method for detecting pseudarthrosis identifies a 1 mm difference in interspinous motion (ISM), which requires calibration of images and relies on anatomic landmarks difficult to visualize. An alternative is to use angles between spinous processes, which does not require calibration and relies on more visible landmarks.

MATERIALS AND METHODS

ISM was measured on dynamic radiographs using the previously published linear method and new angular method. Angles were defined by lines from screw heads to dorsal points of spinous processes. Angular cutoff for fusion was calculated using a regression equation correlating linear and angular measures, based on the 1 mm linear cutoff. Pseudarthrosis was assessed with both cutoffs. Sensitivity, specificity, inter-reliability and intrareliability of angular and linear measures used postoperative computed tomography (CT) as the reference.

RESULTS

A total of 242 fused levels (81 allograft, 84 polyetheretherketone, 40 titanium, 37 standalone cages) were measured in 143 patients (mean age 52.0±11.5, 42%F). 36 patients (66 levels) had 1-year postoperative CTs; 13 patients (13 levels) had confirmed pseudarthrosis. Linear and angular measurements closely correlated ( R =0.872), with 2.3° corresponding to 1 mm linear ISM. Potential pseudarthroses was found in 28.0% and 18.5% levels using linear and angular cutoffs, respectively. Linear cutoff had 85% sensitivity, 87% specificity; angular cutoff had 85% sensitivity, 96% specificity for detecting CT-validated pseudarthrosis. Interclass correlation coefficients were 0.974 and 0.986 (both P <0.001); intrarater reliability averaged 0.953 and 0.974 ( P <0.001 for all) for linear and angular methods, respectively.

CONCLUSIONS

The angular measure for assessing potential pseudarthrosis is as sensitive as and more specific than published linear methods, has high interobserver reliability, and can be used without image calibration.

LEVEL OF EVIDENCE

3.

Does Low Back Pain Improve Following Total Hip Arthroplasty?

BACKGROUND

Frequently, patients indicated for total hip arthroplasty (THA) present with low back pain (LBP) and hip pain. The purpose of this study was to compare patients whose back pain resolved after THA with those where back pain did not resolve and identify how to predict this using spinopelvic parameters.

METHODS

We reviewed a series of 500 patients who underwent THA for unilateral hip osteoarthritis by 2 surgeons. Patients underwent biplanar standing and sitting EOS radiographs pre-operatively. Patients with previous spine surgery or femoral neck fracture were excluded. Demographic data was analyzed at baseline. The Oswestry Disability Index (ODI) scores were calculated pre-operatively and at 1 year postoperatively. Spinopelvic parameters included, pelvic incidence and sacral slope (SS) change from standing to sitting.

RESULTS

Two hundred and four patients (41%) had documented LBP before THA. The Oswestry Disability Index (ODI) for patients improved from 38.9 ± 17.8 pre-operatively to 17.0 ± 10.6 at 1 year post-operatively (P < .001). At 1- and 2-year follow-up, resolution of back pain occurred in 168 (82.4%) and 187 (91.2%) patients, respectively. Pelvic incidence was not predictive of back pain resolution. All patients whose back pain resolved had a sacral slope change from standing to sitting of >10°, while those patients whose back pain did not resolve had a change of <10°.

CONCLUSION

This study demonstrates that symptomatic low back pain (LBP) resolves in 82% of patients after THA. The results of this study may be used to counsel patients on back pain and its resolution following total hip replacement.

Cervical Deformity Correction Fails to Achieve Age-Adjusted Spinopelvic Alignment Targets

OBJECTIVE

To assess whether surgical cervical deformity (CD) patients meet spinopelvic age-adjusted alignment targets, reciprocal, and lower limb compensation changes.

STUDY DESIGN

Retrospective review.

METHODS

CD was defined as C2-C7 lordosis >10°, cervical sagittal vertical angle (cSVA) >4 cm, or T1 slope minus cervical lordosis (TS-CL) >20°. Inclusion criteria were age >18 years and undergoing surgical correction with complete baseline and postoperative imaging. Published formulas were used to create age-adjusted alignment target for pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), sagittal vertical angle (SVA), and lumbar lordosis and thoracic kyphosis (LL-TK). Actual alignment was compared with age-adjusted ideal values. Patients who matched ±10-year thresholds for age-adjusted targets were compared with unmatched cases (under- or overcorrected).

RESULTS

A total of 120 CD patients were included (mean age, 55.1 years; 48.4% women; body mass index, 28.8 kg/m²). For PT, only 24.4% of patients matched age-adjusted alignment, 51.1% overcorrected for PT, and 24.4% undercorrected. For PI-LL, only 27.6% of CD patients matched age-adjusted targets, with 49.4% overcorrected and 23% undercorrected postoperatively. Forty percent of patients matched age-adjusted target for SVA, 41.3% overcorrected, and 18.8% undercorrected. CD patients who had worsened in TS-CL or cSVA postoperatively displayed increased TK (-41.1° to -45.3°, P = 1.06). With lower extremity compensation, CD patients decreased in ankle flexion angle postoperatively (6.1°-5.5°, P = 0.036) and trended toward smaller sacrofemoral angle (199.6-195.6 mm, P = 0.286) and knee flexion (2.6° to -1.1°, P = 0.269).

CONCLUSIONS

In response to worsening CD postoperatively, patients increased in TK and recruited less lower limb compensation. Almost 75% of CD patients did not meet previously established spinopelvic alignment goals, of whom a subset of patients were actually made worse off in these parameters following surgery. This finding raises the question of whether we should be looking at the entire spine when treating CD.

LEVEL OF EVIDENCE: 3

Improved Surgical Correction Relative to Patient-Specific Ideal Spinopelvic Alignment Reduces Pelvic Nonresponse for Severely Malaligned Adult Spinal Deformity Patients

BACKGROUND

Persistent pelvic compensation following adult spinal deformity (ASD) corrective surgery may impair quality of life and result in persistent pathologic lower extremity compensation. Ideal age-specific alignment targets have been proposed to improve surgical outcomes, though it is unclear whether reaching these ideal targets reduces rates of pelvic nonresponse following surgery. Our aim was to assess the relationship between pelvic nonresponse, age-specific alignment, and lower-limb compensation following surgery for ASD.

METHODS

Single-center retrospective cohort study. ASD patients were grouped: those who did not improve in Scoliosis Research Society-Schwab pelvic tilt (PT) modifier (pelvic nonresponders [PNR]), and those who improved (pelvic responders [PR]). Groups were propensity score matched for preoperative PT and assessed for differences in spinal and lower extremity alignment. Rates of pelvic nonresponse were compared across patient groups who were undercorrected, overcorrected, or matched age-specific postoperative alignment targets.

RESULTS

A total of 146 surgical ASD patients, 47.9% of whom showed pelvic nonresponse following surgery, were included. After propensity score matching, PNR (N = 29) and PR (N = 29) patients did not differ in demographics, preoperative alignment, or levels fused; however, PNR patients have less preoperative knee flexion (9° vs 14°, P = 0.043). PNR patients had inferior postoperative pelvic incidence and lumbar lordosis (PI-LL) alignment (17° vs 3°) and greater pelvic shift (53 vs 31 mm). PNR and PR patients did not differ in rates of reaching ideal age-specific postoperative alignment for sagittal vertical axis (SVA) or PI-LL, though patients who matched ideal PT had lower rates of PNR (25.0% vs 75.0%). For patients with moderate and severe preoperative SVA, more aggressive correction relative to either ideal postoperative PT or PI-LL was associated with significantly lower rates of pelvic nonresponse (all P < 0.05).

CONCLUSIONS

For patients with moderate to severe baseline truncal inclination, more aggressive surgical correction relative to ideal age-specific PI-LL was associated with lower rates of pelvic nonresponse. Postoperative alignment targets may need to be adjusted to optimize alignment outcomes for patients with substantial preoperative sagittal deformity.

CLINICAL RELEVANCE

These findings increase our understanding of the poor outcomes that occur despite ideal realignment. Surgical correction of severe global sagittal deformity should be prioritized to mitigate these occurrences.

LEVEL OF EVIDENCE: 3

Characterizing the Effect of Perioperative Narcotic Consumption and Narcotic Prescription Dosing at Discharge on Satisfaction With Pain Control for Patients Undergoing Single-level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

A single-center, retrospective review of prospectively collected data on patients who underwent single-level anterior cervical discectomy and fusions (ACDFs) between October 2014 and October 2019.

OBJECTIVE

To investigate the effect of perioperative narcotic consumption and amount of narcotic prescribed at discharge on patient satisfaction with pain control after single-level ACDF.

SUMMARY OF BACKGROUND DATA

Prior research has demonstrated that opioid prescription habits may be related to physician desire to produce superior patient satisfaction with pain control.

METHODS

Patients with complete Press-Ganey Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey information were analyzed. Inpatient opioid prescriptions were recorded and converted to milligram morphine equivalents (MME) and tablets of 5 mg oxycodone. HCAHPS scores were converted to a Likert-type 5-point scale.

RESULTS

A total of 47 patients met inclusion criteria for this study. Average age was 48.1±10.9 y. Average inpatient opioids prescribed was 102±106 MME. Average opioids prescribed at discharge was 437±342 MME. No statistically significant correlation was found between satisfaction with pain control and opioid consumption while in the hospital [r=-0.106, P=0.483]. Similarly, there was no statistically significant correlation between satisfaction with pain control and opioids prescribed upon discharge [r=-0.185, P=0.219]. No statistically significant correlation was found between date of surgery and inpatient MME consumption [r=-0.113, P=0.450]. Interestingly, more opioids were prescribed at discharge the earlier the date of surgery [r=-0.426, P=0.003]. For every additional month further along in the study period, the odds of a patient reporting a top box score for satisfaction with pain control increased by 5.5% [P=0.025].

CONCLUSION

Our study found no correlation between patient satisfaction with pain control and inpatient opioid dosage or outpatient prescription dosage after single-level ACDF. Moreover, satisfaction with pain control increased over time despite a decrease in MME prescribed at discharge. This suggests that factors other than narcotic consumption play a more important role in patient satisfaction with pain control.

LEVEL OF EVIDENCE

Level III.

Lateral decubitus single position anterior-posterior (AP) fusion shows equivalent results to minimally invasive transforaminal lumbar interbody fusion at one-year follow-up

PURPOSE

This study compares perioperative and 1-year outcomes of lateral decubitus single position circumferential fusion (L-SPS) versus minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for degenerative pathologies.

METHODS

Multicenter retrospective chart review of patients undergoing AP fusion with L-SPS or MIS TLIF. Demographics and clinical and radiographic outcomes were compared using independent samples t tests and chi-squared analyses with significance set at p < 0.05.

RESULTS

A total of 445 patients were included: 353 L-SPS, 92 MIS TLIF. The L-SPS cohort was significantly older with fewer diabetics and more levels fused. The L-SPS cohort had significantly shorter operative time, blood loss, radiation dosage, and length of stay compared to MIS TLIF. 1-year follow-up showed that the L-SPS cohort had higher rates of fusion (97.87% vs. 81.11%; p = 0.006) and lower rates of subsidence (6.38% vs. 38.46%; p < 0.001) compared with MIS TLIF. There were significantly fewer returns to the OR within 1 year for early mechanical failures with L-SPS (0.0% vs. 5.4%; p < 0.001). 1-year radiographic outcomes revealed that the L-SPS cohort had a greater LL (56.6 ± 12.5 vs. 51.1 ± 15.9; p = 0.004), smaller PI-LL mismatch (0.2 ± 13.0 vs. 5.5 ± 10.5; p = 0.004). There were no significant differences in amount of change in VAS scores between cohorts. Similar results were seen after propensity-matched analysis and sub-analysis of cases including L5-S1.

CONCLUSIONS

L-SPS improves perioperative outcomes and does not compromise clinical or radiographic results at 1-year follow-up compared with MIS TLIF. There may be decreased rates of early mechanical failure with L-SPS.

Spinal exposure for anterior lumbar interbody fusion (ALIF) in the lateral decubitus position: anatomical and technical considerations

PURPOSE

Single position surgery has demonstrated to reduce hospital length of stay, operative times, blood loss, postoperative pain, ileus, and complications. ALIF and LLIF surgeries offer advantages of placing large interbody devices under direct compression and can be performed by a minimally invasive approach in the lateral position. Furthermore, simultaneous access to the anterior and posterior column is possible in the lateral position without the need for patient repositioning. The purpose of this study is to outline the anatomical and technical considerations for performing anterior lumbar interbody fusion (ALIF) in the lateral decubitus position.

METHODS

Surgical technique and technical considerations for reconstruction of the anterior column in the lateral position by ALIF at the L4-5 and L5-S1 levels.

RESULTS

Topics outlined in this review include: Operating room layout and patient positioning; surgical anatomy and approach; vessel mobilization and retractor placement for L4-5 and L5-S1 lateral ALIF exposure, in addition to comparative technique of disc space preparation, trialing and implant placement compared to the supine ALIF procedure.

CONCLUSIONS

Anterior exposure performed in the lateral decubitus position allows safe-, minimally invasive access and implant placement in ALIF. The approach requires less peritoneal and vessel retraction than in a supine position, in addition to allowing simultaneous access to the anterior and posterior columns when performing 360° Anterior-Posterior fusion.

Anterior column reconstruction of the lumbar spine in the lateral decubitus position: anatomical and patient-related considerations for ALIF, anterior-to-psoas, and transpsoas LLIF approaches

PURPOSE

Circumferential (AP) lumbar fusion surgery is an effective treatment for degenerative and deformity conditions of the spine. The lateral decubitus position allows for simultaneous access to the anterior and posterior aspects of the spine, enabling instrumentation of both columns without the need for patient repositioning. This paper seeks to outline the anatomical and patient-related considerations in anterior column reconstruction of the lumbar spine from L1-S1 in the lateral decubitus position.

METHODS

We detail the anatomic considerations of the lateral ALIF, transpsoas, and anterior-to-psoas surgical approaches from surgeon experience and comprehensive literature review.

RESULTS

Single-position AP surgery allows simultaneous access to the anterior and posterior column and may combine ALIF, LLIF, and minimally invasive posterior instrumentation techniques from L1-S1 without patient repositioning. Careful history, physical examination, and imaging review optimize safety and efficacy of lateral ALIF or LLIF surgery. An excellent understanding of patient spinal and abdominal anatomy is necessary. Each approach has relative advantages and disadvantages according to the disc level, skeletal, vascular, and psoas anatomy.

CONCLUSIONS

A development of a framework to analyze these factors will result in improved patient outcomes and a reduction in complications for lateral ALIF, transpsoas, and anterior-to-psoas surgeries.

Single position lateral decubitus anterior lumbar interbody fusion (ALIF) and posterior fusion reduces complications and improves perioperative outcomes compared with traditional anterior-posterior lumbar fusion

BACKGROUND CONTEXT

Lateral decubitus single position anterior-posterior (AP) fusion utilizing anterior lumbar interbody fusion and percutaneous posterior fixation is a novel, minimally invasive surgical technique. Single position lumbar surgery (SPLS) with anterior lumbar interbody fusion (ALIF) or lateral lumbar interbody fusion (LLIF) has been shown to be a safe, effective technique. This study directly compares perioperative outcomes of SPLS with lateral ALIF vs. traditional supine ALIF with repositioning (FLIP) for degenerative pathologies.

PURPOSE

To determine if SPLS with lateral ALIF improves perioperative outcomes compared to FLIP with supine ALIF.

STUDY DESIGN/SETTING

Multicenter retrospective cohort study.

PATIENT SAMPLE

Patients undergoing primary AP fusions with ALIF at 5 institutions from 2015 to 2020.

OUTCOME MEASURES

Levels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), and PI-LL mismatch.

METHODS

Retrospective analysis of primary ALIFs with bilateral percutaneous pedicle screw fixation between L4-S1 over 5 years at 5 institutions. Patients were grouped as FLIP or SPLS. Demographic, procedural, perioperative, and radiographic outcome measures were compared using independent samples t-tests and chi-squared analyses with significance set at p <.05. Cohorts were propensity-matched for demographic or procedural differences.

RESULTS

A total of 321 patients were included; 124 SPS and 197 Flip patients. Propensity-matching yielded 248 patients: 124 SPLS and 124 FLIP. The SPLS cohort demonstrated significantly reduced operative time (132.95±77.45 vs. 261.79±91.65 min; p <0.001), EBL (120.44±217.08 vs. 224.29±243.99 mL; p <.001), LOS (2.07±1.26 vs. 3.47±1.40 days; p <.001), and rate of perioperative ileus (0.00% vs. 6.45%; p =.005). Radiation dose (39.79±31.66 vs. 37.54±35.85 mGy; p =.719) and perioperative complications including vascular injury (1.61% vs. 1.61%; p =.000), retrograde ejaculation (0.00% vs. 0.81%, p =.328), abdominal wall (0.81% vs. 2.42%; p =.338), neuropraxia (1.61% vs. 0.81%; p =.532), persistent motor deficit (0.00% vs. 1.61%; p =.166), wound complications (1.61% vs. 1.61%; p =.000), or VTE (0.81% vs. 0.81%; p =.972) were similar. No difference was seen in 90-day return to OR. Similar results were noted in sub-analyses of single-level L4-L5 or L5-S1 fusions. On radiographic analysis, the SPLS cohort had greater changes in LL (4.23±11.14 vs. 0.43±8.07 deg; p =.005) and PI-LL mismatch (-4.78±8.77 vs. -0.39±7.51 deg; p =.002).

CONCLUSIONS

Single position lateral ALIF with percutaneous posterior fixation improves operative time, EBL, LOS, rate of ileus, and maintains safety compared to supine ALIF with prone percutaneous pedicle screws between L4-S1.

Incidence of dysphagia following posterior cervical spine surgery

Abundant literature exists describing the incidence of dysphagia following anterior cervical surgery; however, there is a paucity of literature detailing the incidence of dysphagia following posterior cervical procedures. Further characterization of this complication is important for guiding clinical prevention and management. Patients ≥ 18 years of age underwent posterior cervical fusion with laminectomy or laminoplasty between C1-T1. Pre- and post-operative dysphagia was assessed by a speech language pathologist. The patient cohort was categorized by approach: Laminectomy + Fusion (LF) and Laminoplasty (LP). Patients were excluded from radiographic analyses if they did not have both baseline and follow-up imaging. The study included 147 LF and 47 LP cases. There were no differences in baseline demographics. There were three patients with new-onset dysphagia in the LF group (1.5% incidence) and no new cases in the LP group (p = 1.000). LF patients had significantly higher rates of post-op complications (27.9% LF vs. 8.5% LP, p = 0.005) but not intra-op complications (6.1% LF vs. 2.1% LP, p = 0.456). Radiographic analysis of the entire cohort showed no significant changes in cervical lordosis, cSVA, or T1 slope. Both group comparisons showed no differences in incidence of dysphagia pre and post operatively. Based on this study, the likelihood of developing dysphagia after LF or LP are similarly low with a new onset dysphagia rate of 1.5%.

Epidemiology of scoliosis in cerebral palsy: A population-based study at skeletal maturity

AIM

This study investigated the prevalence of scoliosis in a large, population-based cohort of individuals with cerebral palsy (CP) at skeletal maturity to identify associated risk factors that may inform scoliosis surveillance.

METHODS

Young people with CP born between 1990 and 1992 were reviewed through routine orthopaedic review or a transition clinic. Classification of CP was recorded by movement disorder, distribution, gross and fine motor function. Clinical examination was undertaken and those with clinical evidence of scoliosis or risk factors had radiographs of the spine. Scoliosis severity was measured and categorised by Cobb angle.

RESULTS

Two hundred and ninety-two individuals were evaluated (78% of the birth cohort) at a mean age of 21 years, 4 months (range 16-29 years). Scoliosis (Cobb angle >10°) was found in 41%, with strong associations to the Gross Motor Function Classification System (GMFCS), Manual Abilities Classification System (MACS) and dystonic/mixed movement disorders. Those at GMFCS V were 23.4 times (95%CI 9.9-55.6) more likely to develop scoliosis than those at GMFCS I. Severe curves (Cobb >40°, 13% of the cohort) were found almost exclusively in those functioning at GMFCS IV and V, and were 18.2 times (95%CI 6.9-48.5) more likely to occur in those with dystonia than those with spasticity.

CONCLUSIONS

Scoliosis was very common in young people with CP, with prevalence and severity strongly associated with GMFCS and MACS level and dystonic movement disorder. Severe curves were almost exclusively found in non-ambulant children. Clinical screening for scoliosis should occur for all children with CP, with radiographic surveillance focusing on those functioning at GMFCS IV and V.

Preoperative spinopelvic hypermobility resolves following total hip arthroplasty

AIMS

Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA.

METHODS

This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSS_stand-sit) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at six weeks and a minimum of one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria.

RESULTS

A total of 136 patients were identified as having preoperative spinopelvic hypermobility. At one year after THA, 95% (129/136) of patients were no longer categorized as hypermobile on standing and sitting radiographs (ΔSS_stand-sit < 30°). Mean ΔSS_stand-sit decreased from 36.4° (SD 5.1°) at baseline to 21.4° (SD 6.6°) at one year (p < 0.001). Mean SS_seated increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional cup anteversion. Contralateral hip OA was the only radiological predictor of hypermobility persisting at one year after surgery. The overall reoperation rate was 1.5%.

CONCLUSION

Spinopelvic hypermobility was found to resolve in the majority (95%) of patients one year after THA. The increase in SS_seated was clinically significant, suggesting that current target recommendations for the hypermobile patient (decreased anteversion and inclination) should be revisited. Cite this article: Bone Joint J 2021;103-B(12):1766-1773.

COVID-19 pandemic and elective spinal surgery cancelations - what happens to the patients?

BACKGROUND CONTEXT

The COVID-19 pandemic caused nationwide suspensions of elective surgeries due to reallocation of resources to the care of COVID-19 patients. Following resumption of elective cases, a significant proportion of patients continued to delay surgery, with many yet to reschedule, potentially prolonging their pain and impairment of function and causing detrimental long-term effects.

PURPOSE

The aim of this study was to examine differences between patients who have and have not rescheduled their spine surgery procedures originally cancelled due to the COVID-19 pandemic, and to evaluate the reasons for continued deferment of spine surgeries even after the lifting of the mandated suspension of elective surgeries.

STUDY DESIGN/SETTING

Retrospective case series at a single institution PATIENT SAMPLE: Included were 133 patients seen at a single institution where spine surgery was canceled due to a state-mandated suspension of elective surgeries from March to June, 2020.

OUTCOME MEASURES

The measures assessed included preoperative diagnoses and neurological dysfunction, surgical characteristics, reasons for surgery deferment, and PROMIS scores of pain intensity, pain interference, and physical function.

METHODS

Patient electronic medical records were reviewed. Patients who had not rescheduled their canceled surgery as of January 31, 2021, and did not have a reason noted in their charts were called to determine the reason for continued surgery deferment. Patients were divided into three groups: early rescheduled (ER), late rescheduled (LR), and not rescheduled (NR). ER patients had a date of surgery (DOS) prior to the city's Phase 4 reopening on July 20, 2020; LR patients had a DOS on or after that date. Statistical analysis of the group findings included analysis of variance with Tukey's honestly significant difference (HSD) post-hoc test, independent samples T-test, and chi-square analysis with significance set at p≤.05.

RESULTS

Out of 133 patients, 47.4% (63) were in the ER, 15.8% (21) in the LR, and 36.8% (49) in the NR groups. Demographics and baseline PROMIS scores were similar between groups. LR had more levels fused (3.6) than ER (1.6), p= .018 on Tukey HSD. NR (2.1) did not have different mean levels fused than LR or ER, both p= >.05 on Tukey HSD. LR had more three column osteotomies (14.3%) than ER and (1.6%) and NR (2.0%) p=.022, and fewer lumbar microdiscectomies (0%) compared to ER (20.6%) and NR (10.2%), p=.039. Other surgical characteristics were similar between groups. LR had a longer length of stay than ER (4.2 vs 2.4, p=.036). No patients in ER or LR had a nosocomial COVID-19 infection. Of NR, 2.0% have a future surgery date scheduled and 8.2% (4) are acquiring updated exams before rescheduling. 40.8% (20; 15.0% total cohort) continue to defer surgery over concern for COVID-19 exposure and 16.3% (8) for medical comorbidities. 6.1% (3) permanently canceled for symptom improvement. 8.2% (4) had follow-up recommendations for non-surgical management. 4.1% (2) are since deceased.

CONCLUSION

Over 1/3 of elective spine surgeries canceled due to COVID-19 have not been performed in the 8 months from when elective surgeries resumed in our institution to the end of the study. ER patients had less complex surgeries planned than LR. NR patients continue to defer surgery primarily over concern for COVID-19 exposure. The toll on the health of these patients as a result of the delay in treatment and on their lives due to their inability to return to normal function remains to be seen.

Not Frail and Elderly: How Invasive Can We Go in This Different Type of Adult Spinal Deformity Patient?

STUDY DESIGN

Retrospective review of a single-center spine database.

OBJECTIVE

Investigate the intersections of chronological age and physiological age via frailty to determine the influence of surgical invasiveness on patient outcomes.

SUMMARY OF BACKGROUND DATA

Frailty is a well-established factor in preoperative risk stratification and prediction of postoperative outcomes. The surgical profile of operative patients with adult spinal deformity (ASD) who present as elderly and not frail (NF) has yet to be investigated. Our aim was to examine the surgical profile and outcomes of patients with ASD who were NF and elderly.

METHODS

Patients with ASD 18 years or older, four or greater levels fused, with baseline (BL) and follow-up data were included. Patients were categorized by ASD frailty index: NF, Frail (F), severely frail (SF]. An elderly patient was defined as 70 years or older. Patients were grouped into NF/elderly and F/elderly. SRS-Schwab modifiers were assessed at BL and 1 year (0, +, ++). Logistic regression analysis assessed the relationship between increasing invasiveness, no reoperations, or major complications, and improvement in SRS-Schwab modifiers [Good Outcome]. Decision tree analysis assessed thresholds for an invasiveness risk/benefit cutoff point.

RESULTS

A total of 598 patients with ASD included (55.3 yr, 59.7% F, 28.3 kg/m2). 29.8% of patients were older than 70 years. At BL, 51.3% of patients were NF, 37.5% F, and 11.2% SF. Sixty-sis (11%) patients were NF and elderly. About 24.2% of NF-elderly patients improved in SRS-Schwab by 1 year and had no reoperation or complication postoperatively. Binary regression analysis found a relationship between worsening SRS-Schwab, postop complication, and reoperation with invasiveness score (odds ratio: 1.056 [1.01-1.102], P = 0.011). Risk/benefit cut-off was 10 (P = 0.004). Patients below this threshold were 7.9 (2.2-28.4) times more likely to have a Good Outcome. 156 patients were elderly and F/SF with 16.7% having good outcome, with a risk/benefit cut-off point of less than 8 (4.4 [2.2-9.0], P < 0.001).

CONCLUSION

Frailty status impacted the balance of surgical invasiveness relative to operative risk in an inverse manner, whereas the opposite was seen amongst elderly patients with a frailty status less than their chronologic age. Surgeons should perhaps consider incorporation of frailty status over age status when determining realignment plans in patients of advanced age.Level of Evidence: 3.

The use of minimally invasive interspinous process devices for the treatment of lumbar canal stenosis: a narrative literature review

Minimally invasive interspinous process devices (IPD), including interspinous distraction devices (IDD) and interspinous stabilizers (ISS), are increasingly utilized for treating symptomatic lumbar canal stenosis (LCS). There is ongoing debate around their efficacy and safety over traditional decompression techniques with and without interbody fusion (IF). This study presents a comprehensive review of IPD and investigates if: (I) minimally invasive IDD can effectively substitute direct neural decompression and (II) ISS are appropriate substitutes for fusion after decompression. Articles published up to 22^nd January 2020 were obtained from PubMed search. Relevant articles published in the English language were selected and critically reviewed. Observational studies across different IPD brands consistently show significant improvements in clinical outcomes and patient satisfaction at short-term follow-up. Compared to non-operative treatment, mini-open IDD was had significantly greater quality of life and clinical outcome improvements at 2-year follow-up. Compared to open decompression, mini-open IDD had similar clinical outcomes, but associated with higher complications, reoperation risks and costs. Compared to open decompression with concurrent IF, ISS had comparable clinical outcomes with reduced operative time, blood loss, length of stay and adjacent segment mobility. Mini-open IDD had better outcomes over non-operative treatment in mild-moderate LCS at 2-year follow-up, but had similar outcomes with higher risk of re-operations than open decompression. ISS with open decompression may be a suitable alternative to decompression and IF for stable grade 1 spondylolisthesis and central stenosis. To further characterize this procedure, future studies should focus on examining enhanced new generation IPD devices, longer-term follow-up and careful patient selection.

Fusing to the Sacrum/Pelvis: Does the Risk of Reoperation in Thoracolumbar Fusions Depend on Upper Instrumented Vertebrae (UIV) Selection?

BACKGROUND

There is controversy as to whether fusions should have the upper instrumented vertebrae (UIV) end in the upper lumbar spine or cross the thoracolumbar junction. This study compares outcomes and reoperation rates for thoracolumbar fusions to the sacrum or pelvis with UIV in the lower thoracic versus lumbar spine to determine if there is an increased reoperation rate depending on UIV selection.

METHODS

A retrospective review of prospectively collected data was conducted from a single-center database on adult patients with degeneration and deformity who underwent primary and revision fusions with a caudal level of S1 or ilium between 2012 and 2018. Fusions were classified as anterior, posterior, or combination approach. Revision fusions included patients who had spinal surgery at another institution prior to their revision surgery at the center. Patients were categorized into 1 of 3 groups based on UIV: T9-T11, upper lumbar region (L1-L2), and lower lumbar region (L3-L5). Inclusion criteria were age 18 years or older and at least 1 year of clinical follow-up. Patients were excluded from analysis if they had tumors, infections, or less than 1 year of follow-up after the index procedure.

RESULTS

The reoperation rates for the UIV groups in the thoracic (28%) and upper lumbar (27%) spine were nearly equal in magnitude and were both significantly higher than the reoperation rate in the lower lumbar group (18%, P = .046). Reoperation for the diagnosis of adjacent segment disease was 8.3% in the upper lumbar spine and statistically significantly higher than the reoperation rates for adjacent segment disease in the thoracic (1%) or lower lumbar (4.5%, P = .042) spine. Reoperations for pseudoarthrosis and proximal junctional kyphosis were 13% and 4%, respectively, in the thoracic spine, both of which were statistically significantly different (pseudoarthrosis, P = .035; proximal junctional kyphosis, P = .002) from the reoperation rates for the same diagnoses in the upper lumbar spine (4.6% and 1%) or lower lumbar spine (6.2% and 0%). A multivariate logistical regression model at 2-year follow up did not show a statistically significant difference between reoperation rates between the thoracic and upper lumbar spine UIV groups.

CONCLUSION

Constructs with UIV in the thoracic spine suffer from higher rates of proximal junctional kyphosis and pseudoarthrosis, whereas those with UIV in the upper lumbar spine have higher rates of adjacent segment disease. Given this tradeoff, there is no certain recommendation on what UIV will result in a lower reoperation rate in thoracolumbar fusion constructs to the sacrum or pelvis. Surgeons must evaluate patient characteristics and risks to make the optimal decision.

2021 Otto Aufranc Award: A simple Hip-Spine Classification for total hip arthroplasty : validation and a large multicentre series

AIMS

Patients with spinal pathology who undergo total hip arthroplasty (THA) have an increased risk of dislocation and revision. The aim of this study was to determine if the use of the Hip-Spine Classification system in these patients would result in a decreased rate of postoperative dislocation in patients with spinal pathology.

METHODS

This prospective, multicentre study evaluated 3,777 consecutive patients undergoing THA by three surgeons, between January 2014 and December 2019. They were categorized using The Hip-Spine Classification system: group 1 with normal spinal alignment; group 2 with a flatback deformity, group 2A with normal spinal mobility, and group 2B with a stiff spine. Flatback deformity was defined by a pelvic incidence minus lumbar lordosis of > 10°, and spinal stiffness was defined by < 10° change in sacral slope from standing to seated. Each category determined a patient-specific component positioning. Survivorship free of dislocation was recorded and spinopelvic measurements were compared for reliability using intraclass correlation coefficient.

RESULTS

A total of 2,081 patients met the inclusion criteria. There were 987 group 1A, 232 group 1B, 715 group 2A, and 147 group 2B patients. A total of 70 patients had a lumbar fusion, most had L4-5 (16; 23%) or L4-S1 (12; 17%) fusions; 51 patients (73%) had one or two levels fused, and 19 (27%) had > three levels fused. Dual mobility (DM) components were used in 166 patients (8%), including all of those in group 2B and with > three level fusions. Survivorship free of dislocation at five years was 99.2% with a 0.8% dislocation rate. The correlation coefficient was 0.83 (95% confidence interval 0.89 to 0.91).

CONCLUSION

This is the largest series in the literature evaluating the relationship between hip-spine pathology and dislocation after THA, and guiding appropriate treatment. The Hip-Spine Classification system allows surgeons to make appropriate evaluations preoperatively, and it guides the use of DM components in patients with spinopelvic pathology in order to reduce the risk of dislocation in these high-risk patients. Cite this article: Bone Joint J 2021;103-B(7 Supple B):17-24.

Patient Outcomes After Single-level Coflex Interspinous Implants Versus Single-level Laminectomy

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

The aim of this study was to compare postoperative outcomes of Coflex interspinous device versus laminectomy.

SUMMARY OF BACKGROUND DATA

Coflex Interlaminar Stabilization device (CID) is indicated for one- or two-level lumbar stenosis with grade 1 stable spondylolisthesis in adult patients, as an alternative to laminectomy, or laminectomy and fusion. CID provides stability against progressive spondylolisthesis, retains motion, and prevents further disc space collapse.

METHODS

Patients ≥18 years' old with lumbar stenosis and grade 1 stable spondylolisthesis who underwent either primary single-level decompression and implantation of CID, or single-level laminectomy alone were included with a minimum 90-day follow-up at a single academic institution. Clinical characteristics, perioperative outcomes, and postoperative complications were reviewed until the latest follow-up. χ2 and independent samples t tests were used for analysis.

RESULTS

Eighty-three patients (2007-2019) were included: 37 cases of single-level laminectomy (48.6% female) were compared to 46 single-level CID (50% female). CID cohort was older (CID 69.0 ± 9.4 vs. laminectomy 64.2 ± 11.0, P = 0.042) and had higher American Society of Anesthesiologists (ASA) grade (CID 2.59 ± 0.73 vs. laminectomy 2.17 ± 0.48, P = 0.020). CID patients had higher estimated blood loss (EBL) (97.50 ± 77.76 vs. 52.84 ± 50.63 mL, P = 0.004), longer operative time (141.91 ± 47.88 vs. 106.81 ± 41.30 minutes, P = 0.001), and longer length of stay (2.0 ± 1.5 vs. 1.1 ± 1.0 days, P = 0.001). Total perioperative complications (21.7% vs. 5.4%, P = 0.035) and instrumentation-related complication was higher in CID (10.9% vs. 0% laminectomy group, P = 0.039). There were no other significant differences between the groups in demographics or outcomes.

CONCLUSION

Single-level CID devices had higher perioperative 90-day complications, longer operative time, length of stay, higher EBL compared to laminectomies alone. Similar overall revision and neurologic complication rates were noted compared to laminectomy at last follow-up.Level of Evidence: 3.

Residual lumbar hyperlordosis is associated with worsened hip status 5 years after scoliosis correction in non-ambulant patients with cerebral palsy

BACKGROUND

Cerebral palsy (CP) is a static encephalopathy with progressive musculoskeletal pathology. Non-ambulant children (GMFCS IV and V) with CP have high rates of spastic hip disease and neuromuscular scoliosis. The effect of spinal fusion and spinal deformity on hip dislocation following total hip arthroplasty has been well studied, however in CP this remains largely unknown. This study aimed to identify factors associated with worsening postoperative hip status (WHS) following corrective spinal fusion in children with GMFCS IV and V CP.

METHODS

Retrospective review of GMFSC IV and V CP patients in a prospective multicenter database undergoing spinal fusion, with 5 years follow-up. WHS was determined by permutations of baseline (BL), 1 year, 2 years, and 5 years hip status and defined by a change from an enlocated hip at BL that became subluxated, dislocated or resected post-op, or a subluxated hip that became dislocated or resected. Hip status was analyzed against patient demographics, hip position, surgical variables, and coronal and sagittal spinal alignment parameters. Cutoff values for parameters at which the relationship with hip status was significant was determined using receiver operating characteristic curves. Logistic regression determined odds ratios for predictors of WHS.

RESULTS

Eighty four patients were included. 37 (44%) had WHS postoperatively. ROC analysis and logistic regression demonstrated that the only spinopelvic alignment parameter that significantly correlated with WHS was lumbar hyperlordosis (T12-L5) > 60° (p = 0.028), OR = 2.77 (CI 1.10-6.94). All patients showed an increase in pre-to-postop LL. Change in LL pre-to-postop was no different between groups (p = 0.318), however the WHS group was more lordotic at BL and postop (pre44°/post58° vs pre32°/post51° in the no change group). Age, sex, Risser, hip position, levels fused, coronal parameters, global sagittal alignment (SVA), thoracic kyphosis, and reoperation were not associated with WHS.

CONCLUSION

Postoperative hyperlordosis(> 60°) is a risk factor for WHS at 5 years after spinal fusion in non-ambulant CP patients. WHS likely relates to anterior pelvic tilt and functional acetabular retroversion due to hyperlordosis, as well as loss of protective lumbopelvic motion causing anterior femoracetabular impingement.

LEVEL OF EVIDENCE

III.

Increased cautiousness in adolescent idiopathic scoliosis patients concordant with syringomyelia fails to improve overall patient outcomes

Background:

Adolescent idiopathic scoliosis (AIS) is a common cause of spinal deformity in adolescents. AIS can be associated with certain intraspinal anomalies such as syringomyelia (SM). This study assessed the rate o f SM in AIS patients and compared trends in surgical approach and postoperative outcomes in AIS patients with and without SM.

Methods:

The database was queried using ICD-9 codes for AIS patients from 2003–2012 (737.1–3, 737.39, 737.8, 737.85, and 756.1) and SM (336.0). The patients were separated into two groups: AIS-SM and AIS-N. Groups were compared using t-tests and Chi-squared tests for categorical and discrete variables, respectively.

Results:

Totally 77,183 AIS patients were included in the study (15.2 years, 64% F): 821 (1.2%) – AIS-SM (13.7 years, 58% F) and 76,362 – AIS-N (15.2 years, 64% F). The incidence of SM increased from 2003–2012 (0.9 to 1.2%, P = 0.036). AIS-SM had higher comorbidity rates (79 vs. 56%, P < 0.001). Comorbidities were assessed between AIS-SM and AIS-N, demonstrating significantly more neurological and pulmonary in AIS-SM patients. 41.2% of the patients were operative, 48% of AIS-SM, compared to 41.6% AIS-N. AIS-SM had fewer surgeries with fusion (anterior or posterior) and interbody device placement. AIS-SM patients had lower invasiveness scores (2.72 vs. 3.02, P = 0.049) and less LOS (5.0 vs. 6.1 days, P = 0.001). AIS-SM patients underwent more routine discharges (92.7 vs. 90.9%). AIS-SM had more nervous system complications, including hemiplegia and paraplegia, brain compression, hydrocephalous and cerebrovascular complications, all P < 0.001. After controlling for respiratory, renal, cardiovascular, and musculoskeletal comorbidities, invasiveness score remained lower for AIS-SM patients (P < 0.001).

Conclusions:

These results indicate that patients concordant with AIS and SM may be treated more cautiously (lower invasiveness score and less fusions) than those without SM.

Clinical photographs in the assessment of adult spinal deformity: a comparison to radiographic parameters

OBJECTIVE

The goal of this study was to reliably predict sagittal and coronal spinal alignment with clinical photographs by using markers placed at easily localized anatomical landmarks.

METHODS

A consecutive series of patients with adult spinal deformity were enrolled from a single center. Full-length standing radiographs were obtained at the baseline visit. Clinical photographs were taken with reflective markers placed overlying C2, S1, the greater trochanter, and each posterior-superior iliac spine. Sagittal radiographic parameters were C2 pelvic angle (CPA), T1 pelvic angle (TPA), and pelvic tilt. Coronal radiographic parameters were pelvic obliquity and T1 coronal tilt. Linear regressions were performed to evaluate the relationship between radiographic parameters and their photographic "equivalents." The data were reanalyzed after stratifying the cohort into low-body mass index (BMI) (< 30) and high-BMI (≥ 30) groups. Interobserver and intraobserver reliability was assessed for clinical measures via intraclass correlation coefficients (ICCs).

RESULTS

A total of 38 patients were enrolled (mean age 61 years, mean BMI 27.4 kg/m2, 63% female). All regression models were significant, but sagittal parameters were more closely correlated to photographic parameters than coronal measurements. TPA and CPA had the strongest associations with their photographic equivalents (both r2 = 0.59, p < 0.001). Radiographic and clinical parameters tended to be more strongly correlated in the low-BMI group. Clinical measures of TPA and CPA had high intraobserver reliability (all ICC > 0.99, p < 0.001) and interobserver reliability (both ICC > 0.99, p < 0.001).

CONCLUSIONS

The photographic measures of spinal deformity developed in this study were highly correlated with their radiographic counterparts and had high inter- and intraobserver reliability. Clinical photography can not only reduce radiation exposure in patients with adult spinal deformity, but also be used to assess deformity when full-spine radiographs are unavailable.

Single position circumferential fusion improves operative efficiency, reduces complications and length of stay compared with traditional circumferential fusion

BACKGROUND CONTEXT

Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) with percutaneous posterior screw fixation are two techniques used to address degenerative lumbar pathologies. Traditionally, these anterior-posterior (AP) surgeries involve repositioning the patient from the supine or lateral decubitus position to prone for posterior fixation. To reduce operative time (OpTime) and subsequent complications of prolonged anesthesia, single-position lumbar surgery (SPLS) is a novel, minimally invasive alternative performed entirely from the lateral decubitus position.

PURPOSE

Assess the perioperative safety and efficacy of single position AP lumbar fusion surgery (SPLS).

STUDY DESIGN

Multicenter retrospective cohort study.

PATIENT SAMPLE

Three hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group.

OUTCOME MEASURES

Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, estimated blood loss (EBL), length of stay (LOS), and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence, pelvic tilt, and segmental LL.

METHODS

Patients undergoing primary ALIF and/or LLIF surgery with bilateral percutaneous pedicle screw fixation between L2-S1 were included over a 4-year period. Patients were classified as either traditional repositioned "Flip" surgery or SPLS. Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, EBL, LOS, perioperative complications. Radiographic analysis included LL, pelvic incidence, pelvic tilt, and segmental LL. All measures were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p < .05. Propensity matching was completed where demographic differences were found.

RESULTS

Three hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group. Age, gender, BMI, and CCI were similar between groups. Levels fused (1.47 SPLS vs 1.52 Flip, p = .468) and percent cases including L5-S1 (31% SPLS, 35% Flip, p = .405) were similar between cohorts. SPLS significantly reduced OpTime (103 min vs 306 min, p < .001), EBL (97 vs 313 mL, p < .001), LOS (1.71 vs 4.12 days, p < .001), and fluoroscopy radiation dosage (32 vs 88 mGy, p < .001) compared to Flip. Perioperative complications were similar between cohorts with the exception of postoperative ileus, which was significantly lower in the SPLS group (0% vs 5%, p < .001). There was no significant difference in wound, vascular injury, neurological complications, or Venous Thrombotic Event. There was no significant difference found in 90-day return to operating room (OR).

CONCLUSIONS

SPLS improves operative efficiency in addition to reducing blood loss, LOS and ileus in this large cohort study, while maintaining safety.

Radiation Exposure in Posterior Lumbar Fusion: A Comparison of CT Image-Guided Navigation, Robotic Assistance, and Intraoperative Fluoroscopy

STUDY DESIGN

Retrospective clinical review.

OBJECTIVE

To assess the use of intraoperative computed tomography (CT) image-guided navigation (IGN) and robotic assistance in posterior lumbar surgery and their relationship with patient radiation exposure and perioperative outcomes.

METHODS

Patients ≥18 years old undergoing 1- to 2-level transforaminal lateral interbody fusion in 12-month period were included. Chart review was performed for pre- and intraoperative data on radiation dose and perioperative outcomes. All radiation doses are quantified in milliGrays (mGy). Univariate analysis and multivariate logistic regression analysis were utilized for categorical variables. One-way analysis of variance with post hoc Tukey test was used for continuous variables.

RESULTS

A total of 165 patients were assessed: 12 IGN, 62 robotic, 56 open, 35 fluoroscopically guided minimally invasive surgery (MIS). There was a lower proportion of women in open and MIS groups (P = .010). There were more younger patients in the MIS group (P < .001). MIS group had the lowest mean posterior levels fused (P = .015). Total-procedure radiation, total-procedure radiation/level fused, and intraoperative radiation was the lowest in the open group and highest in the MIS group compared with IGN and robotic groups (all P < .001). Higher proportion of robotic and lower proportion of MIS patients had preoperative CT (P < .001). Estimated blood loss (P = .002) and hospital length of stay (P = .039) were lowest in the MIS group. Highest operative time was observed for IGN patients (P < .001). No differences were observed in body mass index, Charlson Comorbidity Index, and postoperative complications (P = .313, .051, and .644, respectively).

CONCLUSION

IGN and robotic assistance in posterior lumbar fusion were associated with higher intraoperative and total-procedure radiation exposure than open cases without IGN/robotics, but significantly less than MIS without IGN/robotics, without differences in perioperative outcomes. Fluoro-MIS procedures reported highest radiation exposure to patient, and of equal concern is that the proportion of total radiation dose also applied to the surgeon and operating room staff in fluoro-MIS group is higher than in IGN/robotics and open groups.

Age and Gender Confound PROMIS Scores in Spine Patients With Back and Neck Pain

STUDY DESIGN

This was a single-center retrospective review.

OBJECTIVES

To explore how age and gender affect PROMIS scores compared with traditional health-related quality of life (HRQL) in spine patients.

METHODS

Patients presenting with a primary complaint of back pain (BP) or neck pain (NP) were included. Legacy HRQLs were Oswestry Disability Index (ODI), Neck Disability Index (NDI), and Visual Analogue Scale (VAS). PROMIS Physical Function (PF), Pain Intensity (Int), and Pain Interference (Inf) were also administered to patients in a clinical setting. Patients were grouped by chief complaint, age (18-44, 45-64, 65+ years) and gender. Two parallel analyses were conducted to identify the effects of age and gender on patient-reported outcomes. Age groups were compared after propensity-score matching by VAS-pain and gender. Separately, genders were compared after propensity-score matching by age and VAS-pain.

RESULTS

A total of 484 BP and 128 NP patients were matched into gender cohorts (n = 201 in each BP group, 46 in each NP group). Among BP patients, female patients demonstrated worse disability by ODI (44.15 vs 38.45, P = .005); PROMIS-PF did not differ by gender. Among NP patients, neither legacy HRQLs nor PROMIS differed by gender when controlling for NP and age. BP and NP patients were matched into age cohorts (n = 135 in each BP group and n = 14 in each BP group). Among BP patients, ANOVA revealed differences between groups when controlling for BP and gender: ODI (P < .001), PROMIS-PF (P = .018), PROMIS-Int (P < .001) PROMIS-Inf (P < .001). Among NP patients, matched age groups differed significantly in terms of NDI (P = .032) and PROMIS-PF (P = .022) but not PROMIS-Int or PROMIS-Inf.

CONCLUSIONS

Age and gender confound traditional HRQLs as well as PROMIS domains. However, PROMIS offers age and gender-specific scores, which traditional HRQLs lack.

Applying the hip-spine relationship in total hip arthroplasty

Total hip arthroplasty dislocations that occur inside Lewinnek's anatomical safe zone represent a need to better understand the hip-spine relationship. Unfortunately, the use of obtuse and redundant terminology to describe the hip-spine relationship has made it a relatively inaccessible topic in orthopaedics. However, with a few basic definitions and principles, the hip-spine relationship can be simplified and understood to prevent unnecessary dislocations following total hip arthroplasty.In the following text, we use common language to define a normal and abnormal hip-spine relationship, present an algorithm for recognising and treating a high-risk hip-spine patient, and discuss several common, high-risk hip-spine pathologies to apply these concepts. Simply, high-risk hip-spine patients often require subtle adjustments to acetabular anteversion based on radiographic evaluations and should also be considered for a high-offset stem, dual-mobility articulation, or large femoral head for additional protection against instability and dislocation.

The Ankle-Pelvic Angle (APA) and Global Lower Extremity Angle (GLA): Summary Measurements of Pelvic and Lower Extremity Compensation

BACKGROUND

Adult sagittal spinal deformity (SSD) leads to the recruitment of compensatory mechanisms to maintain standing balance. After regional spinal compensation is exhausted, lower extremity compensation is recruited. Knee flexion, ankle flexion, and sacrofemoral angle increase to drive pelvic shift posterior and increase pelvic tilt. We aim to describe 2 summary angles termed ankle-pelvic angle (APA) and global lower extremity angle (GLA) that incorporate all aspects of lower extremity and pelvic compensation in a comprehensive measurement that can simplify radiographic analysis.

METHODS

Full-body sagittal stereotactic radiographs were retrospectively collected and digitally analyzed. Spinal and lower extremity alignment were quantified with existing measures. Two angles-APA and GLA-were drawn as geometrically complementary angles to T1-pelvic angle (TPA) and global sagittal axis (GSA), respectively. Regression analysis was used to represent the predictive relationship between TPA and APA and between GSA and GLA.

RESULTS

A total of 518 propensity score-matched patient records were available for analysis. Patients with lower extremity compensation had higher APA (21.83° versus 19.47°, P = .007) and GLA (6.03° versus 1.19°, P < .001) than those without compensation. APA and GLA demonstrated strong correlation with TPA (r = 0.81) and GSA (r = 0.77), respectively. Furthermore, the change between preoperative and postoperative values were strongly correlative between ΔAPA and ΔTPA (r = 0.71) and between ΔGLA and ΔGSA (r = 0.77). APA above 20.6° and GLA above 3.6° were indicative of lower extremity compensation. Patients with increased GLA values had significantly higher Oswestry Disability Index scores (48.67 versus 41.04, P = .005).

CONCLUSIONS

TPA and GSA are measures of global spinal alignment and APA and GLA, respectively, and are geometrically complementary angles that vary proportionately to SSD and balance the body. APA and GLA increase in SSD patients with lower extremity compensation and decrease with corrective surgery.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

APA and GLA offer a concise and simple method of communicating pelvic and lower extremity compensation.

The Patient-Reported Outcome Measurement Information System (PROMIS) Better Reflects the Impact of Length of Stay and the Occurrence of Complications Within 90 Days Than Legacy Outcome Measures for Lumbar Degenerative Surgery

BACKGROUND

The Patient-Reported Outcome Measurement Information System (PROMIS) and legacy outcome measures like the Oswestry Disability Index (ODI) have not been compared for their sensitivity in reflecting the impact of perioperative complications and length of stay (LOS) in a surgical thoracolumbar population. The purpose of this study is to assess the strength of PROMIS and ODI scores as they correlate with LOS and complication outcomes of surgical thoracolumbar patients.

METHODS

Retrospective cohort study. Included: patients ≥18 years undergoing thoracolumbar surgery with available preoperative and 3-month postoperative ODI and PROMIS scores. Pearson correlation assessed the linear relationships between LOS, complications, and scores for PROMIS (physical function, pain intensity, pain interference) and ODI. Linear regression predicted the relationship between complication incidence and scores for ODI and PROMIS.

RESULTS

Included: 182 patients undergoing thoracolumbar surgery. Common diagnoses were stenosis (62.1%), radiculopathy (48.9%), and herniated disc (47.8%). Overall, 58.3% of patients underwent fusion, and 50.0% underwent laminectomy. Patients showed preoperative to postoperative improvement in ODI (50.2 to 39.0), PROMIS physical function (10.9 to 21.4), pain intensity (92.4 to 78.3), and pain interference (58.4 to 49.8, all P < .001). Mean LOS was 2.7 ± 2.8 days; overall complication rate was 16.5%. Complications were most commonly cardiac, neurologic, or urinary (all 2.2%). Whereas preoperative to postoperative changes in ODI did not correlate with LOS, changes in PROMIS pain intensity (r = 0.167, P = .024) and physical function (r = -0.169, P = .023) did. Complications did not correlate with changes in ODI or PROMIS score; however, postoperative scores for physical function (r = -0.205, P = .005) and pain interference (r = 0.182, P = .014) both showed stronger correlations with complication occurrence than ODI (r = 0.143, P = .055). Regression analysis showed postoperative physical function (R ² = 0.037, P = .005) and pain interference (R ² = 0.028, P = .014) could predict complications; ODI could not.

CONCLUSIONS

PROMIS domains of physical function and pain interference better reflected perioperative complications and LOS than the ODI. These results suggest PROMIS may offer more utility as an outcomes assessment instrument.

LEVEL OF EVIDENCE

3.

Postoperative Prophylactic Antibiotics in Spine Surgery: A Propensity-Matched Analysis

BACKGROUND

Surgical site infections are common and costly complications after spine surgery. Prophylactic antibiotics are the standard of care; however, the appropriate duration of antibiotics has yet to be adequately addressed. We sought to determine whether the duration of antibiotic administration (preoperatively only versus preoperatively and for 24 hours postoperatively) impacts postoperative infection rates.

METHODS

All patients undergoing inpatient spinal procedures at a single institution from 2011 to 2018 were evaluated for inclusion. A minimum of 1 year of follow-up was used to adequately capture postoperative infections. The 1:1 nearest-neighbor propensity score matching technique was used between patients who did and did not receive postoperative antibiotics, and multivariable logistic regression analysis was conducted to control for confounding.

RESULTS

A total of 4,454 patients were evaluated and, of those, 2,672 (60%) received 24 hours of postoperative antibiotics and 1,782 (40%) received no postoperative antibiotics. After propensity-matched analysis, there was no difference between patients who received postoperative antibiotics and those who did not in terms of the infection rate (1.8% compared with 1.5%). No significant decrease in the odds of postoperative infection was noted in association with the use of postoperative antibiotics (odds ratio = 1.17; 95% confidence interval, 0.620 to 2.23; p = 0.628). Additionally, there was no observed increase in the risk of Clostridium difficile infection or in the short-term rate of infection with multidrug-resistant organisms.

CONCLUSIONS

There was no difference in the rate of surgical site infections between patients who received 24 hours of postoperative antibiotics and those who did not. Additionally, we found no observable risks, such as more antibiotic-resistant infections and C. difficile infections, with prolonged antibiotic use.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A cost benefit analysis of increasing surgical technology in lumbar spine fusion

BACKGROUND CONTEXT

Numerous advances have been made in the field of spine fusion, such as minimally invasive (MIS) or robotic-assisted spine surgery. However, it is unknown how these advances have impacted the cost of care.

PURPOSE

Compare the economic outcomes of lumbar spine fusion between open, MIS, and robot-assisted surgery patients.

STUDY DESIGN/SETTING

Retrospective review of a single center spine surgery database.

PATIENT SAMPLE

Three hundred sixty propensity matched patients.

OUTCOME MEASURES

Costs, EuroQol-5D (EQ5D), cost per quality adjusted life years (QALY).

METHODS

Inclusion criteria: surgical patients >18 years undergoing lumbar fusion surgery. Patients were categorized into 3 groups based on procedure type: open, MIS, or robotic. Open patients undergoing poster spinal fusion were considered as the control group. MIS patients included those undergoing transforaminal or lateral lumbar interbody fusion with percutaneous screws. Robotic patients were those undergoing robot-assisted fusion. Propensity score matching was performed between all groups for the number of levels fused. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims for ICD-9 codes. For robotic cases, costs were reflective of operational fees and initial purchase cost. Complications and comorbidities and major complications and comorbidities were assessed according to CMS.gov manual definitions. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs per QALY were calculated for both 1 year and life expectancy, assuming no loss of benefit. A 10,000 trial Monte Carlo simulation with probabilistic sensitivity analysis (PSA) assessed our model parameters and costs.

RESULTS

Three hundred sixty propensity matched patients (120 open, 120 MIS, 120 robotic) met inclusion criteria. Descriptive statistics for the cohort were: age 58.8±13.5, 50% women, BMI 29.4±6.3, operative time 294.4±119.0, LOS 4.56±3.31 days, estimated blood loss 515.9±670.0 cc, and 2.3±2.2 average levels fused. Rates of post-op complications were significantly higher in robotic cases versus open and MIS (43% vs. 21% and 22% for open and MIS, p<.05). However, revision rates were comparable between all groups (3% open, 3% MIS, 5% robotic, p>.05). After factoring in complications, revisions, and purchasing and operating fees, the costs of robotic cases was significantly higher than both open and MIS surgery ($60,047.01 vs. $42,538.98 open and $41,471.21 MIS). In a subanalysis of 42 patients with baseline (BL) and 1Y EQ5D data, the cost per QALY at 1Y for open, MIS, and robot-assisted cases was $296,624.48, $115,911.69, and $592,734.30. If utility gained was sustained to life expectancy, the cost per QALY was $14,905.75, $5,824.71, $29,785.64 for open, MIS, and robot-assisted cases. Results of the PSA were consistent with MIS surgery having the most incremental cost effectiveness when compared to open and robotic surgery.

CONCLUSIONS

Numerous advances have been made in the field of spine surgery, however, there has been limited discussion of the effect these advances have on economic outcomes. When matched for levels fused, robot-assisted surgery patients had significantly higher rates of complications and 30% higher costs of surgery compared to minimally invasive and open spine surgery patients. While 1 year economic outcomes were not optimal for robotic surgery cases, the projected costs per QALYs at life expectancy were well below established acceptable thresholds. The above findings may be reflective of an educational learning curve and emerging surgical technologies undergoing progressive refinement.

Trends in Pain Medication Prescriptions and Satisfaction Scores in Spine Surgery Patients at a Single Institution

BACKGROUND

As the opioid crisis has gained national attention, there have been increasing efforts to decrease opioid usage. Simultaneously, patient satisfaction has been a crucial metric in the American health care system and has been closely linked to effective pain management in surgical patients. The purpose of this study was to examine rates of pain medication prescription and concurrent patient satisfaction in spine surgery patients.

METHODS

A total of 1729 patients undergoing spine surgery between June 25, 2017, and June 30, 2018, at a single institution by surgeons performing ≥20 surgeries per quarter, with medication data during hospitalization available, were assessed. Patients were evaluated for nonopioid pain medication prescription rates and morphine milligram equivalents (MME) of opioids used during hospitalization. Of the total cohort, 198 patients were evaluated for Press Ganey Satisfaction Survey responses. A χ² test of independence was used to compare percentages, and 1-way analysis of variance was used to compare means across quarters.

RESULTS

The mean total MME per patient hospitalization was 574.46, with no difference between quarters. However, mean MME per day decreased over time (P = .048), with highest mean 91.84 in Quarter 2 and lowest 77.50 in Quarter 4. Among all procedures, acetaminophen, nonsteroidal anti-inflammatory drugs, and steroid prescription rates increased, whereas benzodiazepine and γ-aminobutyric acid-analog prescriptions decreased. There were no significant differences between quarters for mean hospital ratings (P = .521) nor for responses to questions from the Press Ganey Satisfaction Survey regarding how often staff talk about pain (P = .164), how often staff talk about pain treatment (P = .595), or whether patients recommended the hospital (P = .096). There were also no differences between quarters for responses in all other patient satisfaction questions (P value range, .359-.988).

CONCLUSIONS

Over the studied time period, opioid use decreased and nonopioid prescriptions increased during hospitalization, whereas satisfaction scores remained unchanged. These findings indicate an increasing effort in reducing opioid use among providers and suggest the ability to do so without affecting overall satisfaction rates.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

The opioid epidemic has highlighted the need to reduce opioid usage in orthopedic spine surgery. This study reviews the trends for inpatient management of post-op pain in orthopedic spine surgery patients in relation to patient satisfaction. There was a significant increase in non-opioid analgesic pain medications, and a reduction in opioids during the study period. During this time, patient satisfaction as measured by Press-Ganey surveys did not show a decrease. This demonstrates that treatment of post-operative pain in orthopedic spine surgery patients can be managed with less opioids, more multimodal analgesia, and patient satisfaction will not be affected.

A Simpler, Modified Frailty Index Weighted by Complication Occurrence Correlates to Pain and Disability for Adult Spinal Deformity Patients

BACKGROUND

The Miller et al adult spinal deformity frailty index (ASD-FI) correlates with complication risk; however, its development was not rooted in clinical outcomes, and the 40 factors needed for its calculation limit the index's clinical utility. The present study aimed to develop a simplified, weighted frailty index for ASD patients METHODS: This study is a retrospective review of a single-center database. Component ASD-FI parameters contributing to overall ASD-FI score were assessed via Pearson correlation. Top significant, clinically relevant factors were regressed against ASD-FI score to generate the modified ASD-FI (mASD-FI). Component mASD-FI factors were regressed against incidence of medical complications, and factor weights were calculated from regression of these coefficients. Total mASD-FI score ranged from 0 to 21, and was calculated by summing weights of expressed parameters. Linear regression and published ASD-FI cutoffs generated corresponding mASD-FI frailty cutoffs: not frail (NF, <7), frail (7-12), severely frail (SF, >12). Analysis of variance assessed the relationship between frailty category and validated baseline measures of pain and disability at baseline.

RESULTS

The study included 50 ASD patients. Eight factors were included in the mASD-FI. Overall mean mASD-FI score was 5.7 ± 5.2. Combined, factors comprising the mASD-FI showed a trend of predicting the incidence of medical complications (Nagelkerke R ² = 0.558; Cox & Snell R ² = 0.399; P = .065). Breakdown by frailty category is NF (70%), frail (12%), and SF (18%). Increasing frailty category was associated with significant impairments in measures of pain and disability: Oswestry Disability Index (NF: 23.4; frail: 45.0; SF: 49.3; P < .001), SRS-22r (NF: 3.5; frail: 2.6; SF: 2.4; P = .001), Pain Catastrophizing Scale (NF: 41.9; frail: 32.4; SF: 27.6; P < .001), and NRS Leg Pain (NF: 2.3; frail: 7.2; SF: 5.6; P = .001).

CONCLUSIONS

This study modifies an existing ASD frailty index and proposes a weighted, shorter mASD-FI. The mASD-FI relies less on patient-reported variables, and it weights component factors by their contribution to adverse outcomes. Because increasing mASD-FI score is associated with inferior clinical measures of pain and disability, the mASD-FI may serve as a valuable tool for preoperative risk assessment.

Expandable cages increase the risk of intraoperative subsidence but do not improve perioperative outcomes in single level transforaminal lumbar interbody fusion

BACKGROUND CONTEXT

Expandable cages (EXP) are being more frequently utilized in transforaminal lumbar interbody fusions (TLIF). EXP were designed to reduce complications related to neurological retraction, enable better lordosis restoration, and improve ease of insertion, particularly in the advent of minimally invasive surgical (MIS) techniques, however they are exponentially more expensive than the nonexpandable (NE) alternative.

PURPOSE

To investigate the clinical results of expandable cages in single level TLIF.

STUDY DESIGN/SETTING

Retrospective review at a single institution.

PATIENT SAMPLE

Two hundred and fifty-two single level TLIFs from 2012 to 2018 were included.

OUTCOME MEASURES

Clinical characteristics, perioperative and neurologic complication rates, and radiographic measures.

METHODS

Patients ≥18 years of age who underwent single level TLIF with minimum 1 year follow-up were included.

OUTCOME MEASURES

clinical characteristics, perioperative and neurologic complications. Radiographic analysis included pelvic incidence-lumbar lordosis (PI-LL) mismatch, segmental lumbar lordosis (LL) mismatch, disc height restoration, and subsidence ≥2 mm. Statistical analysis included independent t tests and chi-square analysis. For nonparametric variables, Mann-Whitney U test and Spearman partial correlation were utilized. Multivariate regression was performed to assess relationships between surgical variables and recorded outcomes. For univariate analysis significance was set at p<.05. Due to the multiple comparisons being made, significance for regressions was set at p<.025 utilizing Bonferroni correction.

RESULTS

Two hundred and fifty-two TLIFs between 2012 and 2018 were included, with 152 NE (54.6% female, mean age 59.28±14.19, mean body mass index (BMI) 28.65±5.38, mean Charlson Comorbidity Index (CCI) 2.20±1.89) and 100 EXP (48% female, mean age 58.81±11.70, mean BMI 28.68±6.06, mean CCI 1.99±1.66) with no significant differences in demographics. Patients instrumented with EXP cages had a shorter length of stay (3.11±2.06 days EXP vs. 4.01±2.64 days NE; Z=-4.189, p<.001) and a lower estimated blood loss (201.31±189.41 mL EXP vs. 377.82±364.06 mL NE; Z=-6.449, p<.001). There were significantly more MIS-TLIF cases and bone morphogenic protein (BMP) use in the EXP group (88% MIS, p<.001 and 60% BMP, p<.001) as illustrated in Table 1. There were no significant differences between the EXP and NE groups in rates of radiculitis and neuropraxia. In multivariate regression analysis, EXP were not associated with a difference in perioperative outcomes or complications. Radiographic analyses demonstrated that the EXP group had a lower PI-LL mismatch than the NE cage group at baseline (3.75±13.81° EXP vs. 12.75±15.81° NE; p=.001) and at 1 year follow-up (3.81±12.84° EXP vs. 8.23±12.73° NE; p=.046), but change in regional and segmental alignment was not significantly different between groups. Multivariate regression demonstrated that EXP use was a risk factor for intraoperative subsidence (2.729[1.185-6.281]; p=.018).

CONCLUSIONS

Once technique was controlled for, TLIFs utilizing EXP do not have significantly improved neurologic or radiographic outcomes compared with NE. EXP increase risk of intraoperative subsidence. These results question the value of the EXP given the higher cost.

Sports-related Cervical Spine Fracture and Spinal Cord Injury: A Review of Nationwide Pediatric Trends

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Assess trends in sports-related cervical spine trauma using a pediatric inpatient database.

SUMMARY OF BACKGROUND DATA

Injuries sustained from sports participation may include cervical spine trauma such as fractures and spinal cord injury (SCI). Large database studies analyzing sports-related cervical trauma in the pediatric population are currently lacking.

METHODS

The Kid Inpatient Database was queried for patients with external causes of injury secondary to sports-related activities from 2003 to 2012. Patients were further grouped for cervical spine injury (CSI) type, including C1-4 and C5-7 fracture with/without spinal cord injury (SCI), dislocation, and SCI without radiographic abnormality (SCIWORA). Patients were grouped by age into children (4-9), pre-adolescents (Pre, 10-13), and adolescents (14-17). Kruskall-Wallis tests with post-hoc Mann-Whitney U's identified differences in CSI type across age groups and sport type. Logistic regression found predictors of TBI and specific cervical injuries.

RESULTS

A total of 38,539 patients were identified (12.76 years, 24.5% F). Adolescents had the highest rate of sports injuries per year (P < 0.001). Adolescents had the highest rate of any type of CSI, including C1-4 and C5-7 fracture with and without SCI, dislocation, and SCIWORA (all P < 0.001). Adolescence increased odds for C1-4 fracture w/o SCI 3.18×, C1-4 fx w/ SCI by 7.57×, C5-7 fx w/o SCI 4.11×, C5-7 w/SCI 3.63×, cervical dislocation 1.7×, and cervical SCIWORA 2.75×, all P < 0.05. Football injuries rose from 5.83% in 2009 to 9.14% in 2012 (P < 0.001), and were associated with more SCIWORA (1.6% vs. 1.0%, P = 0.012), and football injuries increased odds of SCI by 1.56×. Concurrent TBI was highest in adolescents at 58.4% (pre: 26.6%, child: 4.9%, P < 0.001), and SCIWORA was a significant predictor for concurrent TBI across all sports (odds ratio: 2.35 [1.77-3.11], P < 0.001).

CONCLUSION

Adolescent athletes had the highest rates of upper/lower cervical fracture, dislocation, and SCIWORA. Adolescence and SCIWORA were significant predictors of concurrent TBI across sports. The increased prevalence of CSI with age sheds light on the growing concern for youth sports played at a competitive level, and supports recently updated regulations aimed at decreasing youth athletic injuries.

LEVEL OF EVIDENCE

3.

Lewinnek Safe Zone References are Frequently Misquoted

Background

Optimal acetabular component orientation in total hip arthroplasty (THA) is a necessity in achieving a stable implant. Although there has been considerable debate in the literature concerning the safe zone, to date, there has not been any review to determine if these references are consistent with the definition applied by Lewinnek et al. in 1978. Therefore, this article aims to examine the available literature in the PubMed database to determine how often a correct reference to the safe zone as defined by Lewinnek was applied to discussions regarding THA.

Methods

A search for literature in the PubMed database was performed for articles from 1978 to 2019. Search criteria included terms ‘Lewinnek,’ ‘safe zone,’ and ‘total hip arthroplasty.’ Exclusions included abstract-only articles, non-English articles, articles unrelated to THA, and those lacking full content.

Results

A review of literature yielded 147 articles for inclusion. Overall, only 11% (17) cited the Lewinnek article correctly. Forty-five percent (66) of articles referenced measurements in the supine position, 18% (26) referenced other positions, and 37% (55) did not specify. Nineteen percent (28) reported measurements of the acetabular cup orthogonal to the anterior pelvic plane, while 73% (108) did not, and 7% (11) did not specify. Twenty-three percent (34) measured from computed tomography scans instead of other methods.

Conclusions

In the discussion of the safe zone regarding THA, only 11% of articles listed are consistent with the definition established by Lewinnek. This warrants further investigation into a consistent application of the term and its implications for THA implant stability and dislocation rates.