Indications for anterior lumbar interbody fusion

Fatty infiltration in the multifidus predicts screw-loosening following short-segment decompression and fusion: proof of why we should protect and rehabilitate the paraspinal muscles

PURPOSE

Screw-loosening is a common instrumentation-related complication following fusion. Patients who present with pain and neurological symptoms due to screw-loosening require revision. It has been reported that fat-infiltrated and/or atrophied paraspinal muscles were associated with low back pain, disability, radiculopathy, and instrumentation-related failures. However, there is limited and conflicting knowledge regarding the association of paraspinal muscles with screw-loosening. In the present study, we aimed to identify whether fatty infiltration in the paraspinal muscles was associated with screw-loosening.

METHODS

A retrospective analysis of the clinical and radiological data of the patients who underwent short-segment decompression and fusion for lumbar spinal stenosis (LSS) at a tertiary spine clinic between 2013 and 2023. Goutallier's classification system was used for grading fatty infiltration in the paraspinal muscles.

RESULTS

Patients with screw-loosening had fattier multifidus at the upper lumbar spine (particularly L2-L3, cephalad to the upper instrumented level of L3-L4) compared to those without screw-loosening. In univariate analysis fatty multifidus at L2-L3 level, elder age, and male sex had ORs of 1.509 (p = 0.008), 1.116 (p = 0.001) and 4.702 (p = 0.004), respectively. In multivariate analysis fatty multifidus at L2-L3 level, elder age and male sex had ORs 1.428 (p = 0.043), 1.109 (p = 0.003), and 5.911 (p = 0.004), respectively.

CONCLUSION

Fatty infiltration in the multifidus muscle (particularly in the one at the cranial end of the fusion mass) is predictive for screw-loosening following short-segment lumbar decompression and fusion for LSS. Preserving multifidus in subjects is essential to prevent future long-term complications of spine surgery.

Incidence of intraoperative morbidities in anterior lumbar interbody fusion (ALIF): a comprehensive study of 5,299 levels

CONTEXT

Anterior Lumbar Interbody Fusion (ALIF) is performed via an abdominal approach to remove the intervertebral disc. Although academic reports suggest low intraoperative complication rates, the available data show significant variability. There is a lack of large-scale, robust studies that consistently evaluate the morbidity rates associated with this procedure.

OBJECTIVE

This study evaluates the operative parameters of this procedure based on a substantial number of cases.

STUDY DESIGN

A retrospective case series.

METHODS

Patient data were retrospectively collected from the database of the Instituto de Acessos à coluna Aécio Dias (IAAD). All patients aged 18 years or older who underwent ALIF surgery were included in the study. Patients who underwent other surgical approaches were excluded. Data on intraoperative morbidity (vascular injuries, injuries to intra- and extraperitoneal organs, dural sac injuries, and nerve root injuries), operative time, and blood loss were collected and analyzed.

RESULTS

A total of 3,438 patients were evaluated. 1,671 (48.6%) were male, and 1,767 (51.4%) were female. The mean age was 47.87 ± 12.10 years, ranging from 18 to 88 years. The reported incidence of complications was as follows: vascular injuries (3.25%), nerve root injuries (0.09%), dural sac injuries (0.06%), and injuries to intra- and extraperitoneal organs (0.03%).

CONCLUSIONS

ALIF surgery demonstrated safety and low morbidity. A multidisciplinary team, including access surgeons, played a pivotal role in reducing vascular complications, optimizing surgical times, and minimizing blood loss, aligning with the standards reported in the literature.

The modern application of anterior lumbar interbody fusion (ALIF): a narrative review of perioperative considerations and surgical pearls

Background and Objective

Anterior lumbar interbody fusion (ALIF) has become a pivotal technique in managing chronic back pain, radiculopathy, neurogenic claudication, and spinal deformity. This review aims to compare ALIF with other fusion methods, highlight its advantages and disadvantages, and provide surgical insights to enhance perioperative outcomes.

Methods

A comprehensive literature search was conducted using databases such as PubMed, Embase, and Cochrane Library, focusing on publications from the past two decades. Articles were selected based on relevance, study design, and the inclusion of key perioperative considerations and surgical techniques. Only English-language studies were considered.

Key Content and Findings

This review examines the historical evolution of ALIF, its current clinical applications, and the development of associated surgical techniques. It discusses preoperative evaluations, imaging strategies, and patient selection criteria. Key findings highlight that ALIF offers superior disc height restoration and segmental lordosis compared to other fusion techniques. However, it presents unique challenges such as potential vascular and visceral injuries. The review also outlines critical surgical pearls for effective ALIF execution and strategies to mitigate common complications like subsidence and nerve root injuries.

Conclusions

ALIF is a robust technique for lumbar spine pathology, providing significant benefits in appropriate patient populations. This review underscores the importance of meticulous surgical planning and technique to optimize outcomes. Future research should focus on long-term comparative studies and the development of enhanced surgical instruments and protocols. Implementing these insights into clinical practice may improve patient outcomes and influence surgical guidelines and policies.

Physical Therapy for Patients with Thoracolumbar Vertebral Fractures

Vertebral fractures are a common cause of back pain and pain-related functional impairments in elderly patients. Despite their widespread occurrence, vertebral fractures frequently remain underdiagnosed, often leading to suboptimal management and poor clinical outcomes. This review specifically examines the role of physical therapy (PT) in managing vertebral fractures, describing current literature and evidence-based guidelines from the American Physical Therapy Association and the American Academy of Orthopaedic Surgeons. PT following vertebral fractures has been shown to significantly improve back pain and patient-reported outcomes, with studies even showing a correlation between resistance and aerobic training with improved bone mineral density. These findings highlight the need for interdisciplinary care and comprehensive PT interventions to address the growing burden of vertebral fractures as their incidence rises with the aging population.

Anterior lumbar discectomy and fusion: an effective technique in treating lumbar disc herniation-- a retrospective case study

OBJECTIVE

Lumbar disc herniation is a syndrome triggered by degenerative changes in the intervertebral disc. Based on the technique of ALIF, combining the concept of Anterior Cervical Discectomy and Fusion (ACDF), we summarized Anterior Lumbar Discectomy Fusion (ALDF) in our previous clinical experience. This study is to explore the clinical efficacy and safety of this method for treating lumbar disc herniation.

METHOD

We retrospectively analyzed the medical records of 44 patients with L5/S1 lumbar disc herniation treated in the Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, from December 2020 to April 2023. The Japan orthopaedic association (JOA) scoring system, Oswestry disability index (ODI), and Numerical rating scale (NRS, to evaluate pain) were used to assess patients' clinical symptoms before and after surgery. Radiographic examinations, including X-ray, CT, and MRI, were performed to record preoperative and postoperative imaging indicators, such as surgical segment, intervertebral disc height, and dural sac cross-sectional area. Postoperative follow-up records noted the time of bony fusion and postoperative complications.

RESULTS

All 44 patients successfully completed the ALDF operation. No vascular, ureteral, or abdominal organ damage occurred during the operation. All patients' symptoms were alleviated. Postoperative CT scans revealed a significant improvement in intervertebral disc height (7.32 ± 2.07 mm vs. 12.15 ± 1.79 mm, p < 0.05). Postoperative MRI scans showed a significant increase in the cross-sectional area of the dural sac (0.95 ± 0.33cm2 vs. 1.30 ± 0.37cm2, p < 0.05). X-ray re-examination 6 months after surgery showed bony fusion in all operated segments. 12 months postoperatively, the average JOA was 25.57 ± 2.29, ODI was 4.45 ± 3.43%, and NRS was 1.43 ± 1.13, all significantly improved compared to preoperative levels, p < 0.05. There were no complications such as implant failure, cage subsidence, or wound infection.

CONCLUSION

ALDF provides an effective treatment strategy for patients with lumbar disc herniation. This procedure allows direct removal of protruding discs and calcified posterior longitudinal ligaments under the microscope, achieving the goal of direct decompression of the surgical segment. At the same time, it can reduce the damage to posterior muscles and skeletal structures caused by surgery. Comprehensive preoperative assessment and meticulous microscopic operation can help avoid complications such as nerve and vascular injuries.

Burden and Predictors of Incisional Hernia Following Anterior Lumbar Fusion: A National Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To determine the incidence and identify independent predictors of incisional hernia following anterior lumbar interbody fusion (ALIF).

METHODS

The PearlDiver national database was queried to identify patients who underwent ALIF. Patients were stratified based on the presence or absence of an incisional hernia diagnosis. Chi-squared and Student's t-tests were used to identify demographic and comorbidities between the 2 cohorts. Multivariate logistic regression analysis was performed to identify independent risk factors for incisional hernia development.

RESULTS

A total of 165,110 patients underwent ALIF during the study period, of whom 4164 (2.52%) developed an incisional hernia. The mean and median time to diagnosis were 1093 ± 1030 days and 728 days, respectively. Independent risk factors for incisional hernia included obesity (aOR: 1.19), smoking (aOR: 1.09), chronic obstructive pulmonary disease (COPD) (aOR: 1.25), ascites (aOR: 2.16), surgical site infection (SSI) (aOR: 1.96), malnutrition (aOR:1.56), and two-level ALIF (aOR: 1.12) (all P < 0.05).

CONCLUSION

The incidence of incisional hernia following ALIF is 2.52%, with obesity, smoking, COPD, ascites, SSI, malnutrition, and two-level surgeries identified as independent risk factors. Spine surgeons should implement risk mitigation strategies including weight loss, smoking cessation, and nutritional support. Future research should explore the impact of surgical techniques on hernia risk such as open vs minimally invasive ALIF, incision type, and suture methods, on hernia prevention, as well as evaluate the efficacy of targeted rehabilitation protocols in reducing hernia risk.

Anterior Lumbar Interbody Fusion (ALIF) Versus Full-Endoscopic/Percutaneous TLIF With a Large-Footprint Interbody Cage: A Comparative Observational Study

STUDY DESIGN

Exploratory prospective observational case-control study.

OBJECTIVES

Aim of this study was to compare clinical and radiologic outcome, as well as peri-operative complications, of anterior lumbar interbody fusion (ALIF) and full-endoscopic/percutaneous trans-Kambin transforaminal lumbar interbody fusion (pTLIF) with a large-footprint interbody cage.

METHODS

Patients that underwent elective ALIF and pTLIF with a large-footprint interbody cage were prospectively evaluated. Clinical follow-up was measured pre- and post-operatively with Visual Analogic Scale and Oswestry Disability Index scores. Radiologic outcome was assessed with a computed tomography scan and standing films at 12 months.

RESULTS

44 patients underwent ALIF and 43 pTLIF surgery (total 87 cases). Clinical pre- and post-operative scores were comparable between both groups with 33.4 months mean follow-up. Median surgical time was significantly lower for pTLIF (28 minutes) compared to ALIF (72 minutes). Radiologic outcome was favorable for ALIF with a significantly higher increase in segmental lordosis compared to pTLIF. Fusion rates did not significantly differ between both groups. ALIF showed significantly less cage subsidence than pTLIF. Complications included 9 (21%) cases with transitory post-operative radiculitis for ALIF and 12 (28%) for pTLIF; post-operative partial muscle weakness 3(6%) cases for ALIF and 4 (9%) for pTLIF. Two (4%) cases required revision surgery for pTLIF.

CONCLUSIONS

ALIF and trans-Kambin pTLIF obtained comparable clinical outcome and fusion rates, while segmental lordosis restoration was favorable for ALIF. pTLIF required less surgery time and presented less intra-operative complications, while ALIF reported lower rates of post-operative subsidence, revision surgery and complications during follow-up.

Bone graft substitutes used in anterior lumbar interbody fusion: a contemporary systematic review of fusion rates and complications

Background

Anterior lumbar interbody fusion (ALIF) uses a broad-footprint interbody cage designed to maximize fusion rates for treating degenerative disc disease. Bone graft substitutes are being increasingly utilized during ALIF to replace or supplement autologous iliac crest bone grafts. This approach aims to optimize fusion efficacy while minimizing associated postoperative complications. The objective of this systematic review was to examine recent studies on fusion rates and postoperative complications associated with bone graft substitutes used in ALIF.

Methods

We conducted a systematic review of the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, MEDLINE, and PubMed databases, to critically examine a decade of research (January 1, 2012, to July 6, 2023) on the effectiveness and safety of various bone graft substitutes in ALIF. This timeframe was chosen to build on a previous systematic review published in 2013. The PRISMA guidelines were used.

Results

In total, 27 articles met our stringent inclusion and exclusion criteria. A substantial portion of these studies (67%) focused on recombinant human bone morphogenetic protein-2 (rhBMP-2) and highlighted its efficacy for achieving high fusion rates. However, the literature presents a dichotomy regarding the association of rhBMP-2 with increased postoperative complications. Notably, the methodologies for evaluating spinal fusion varied across studies. Only one-third of studies employed computed tomography to assess interbody fusion at 12 months postoperatively, highlighting the urgent need to establish uniform fusion criteria to facilitate more accurate comparative analyses. Moreover, there was considerable variability in the criteria used for diagnosing and detecting postoperative complications, significantly influencing the reported incidence rates.

Conclusions

This review underscores the need for continued research into bone graft substitutes, particularly focusing on assessment of long-term complications. Future research endeavors should concentrate on developing comprehensive clinical guidelines to aid in the selection of the most suitable bone graft substitutes for use in ALIF, thereby enhancing patient outcomes and surgical efficacy.

Technique, Safety, and Accuracy Assessment of Percutaneous Pedicle Screw Placement Utilizing Computer-Assisted Navigation in Lateral Decubitus Single-Position Surgery

BACKGROUND

Percutaneous pedicle screw (PPS) placement has become a pivotal technique in spinal surgery, increasing surgical efficiency and limiting the invasiveness of surgical procedures. The aim of this study was to analyze the accuracy of computer-assisted PPS placement with a standardized technique in the lateral decubitus position.

METHODS

A retrospective review of prospectively collected data was performed on 44 consecutive patients treated between 2021 and 2023 with lateral decubitus single-position surgery. PPS placement was assessed by computed tomography scans, and breaches were graded based on the magnitude and direction of the breach. Facet joint violations were assessed. Variables collected included patient demographics, indication, intraoperative complications, operative time, fluoroscopy time, estimated blood loss, and length of stay.

RESULTS

Forty-four patients, with 220 PPSs were identified. About 79.5% of all patients underwent anterior lumbar interbody fusion only, 13.6% underwent lateral lumbar interbody fusion only, and 6.8% received a combination of both anterior lumbar interbody fusion and lateral lumbar interbody fusion. Eleven screw breaches (5%) were identified: 10 were Grade II breaches (<2 mm), and 1 was a Grade IV breach (>4 mm). All breaches were lateral. About 63.6% involved down-side screws indicating a trend toward the laterality of breaches for down-side pedicles. When analyzing breaches by level, 1.2% of screws at L5, 13% at L4, and 11.1% at L3 demonstrated Grade II breaches. No facet joint violations were noted.

CONCLUSION

PPS placement utilizing computer-assisted navigation in lateral decubitus single-position surgery is both safe and accurate. An overall breach rate of 5% was found; considering a safe zone of 2 mm, only 1 screw (0.5%) demonstrated a relevant breach.

CLINICAL RELEVANCE

PPS placement is both safe and accurate. Breaches are rare, and when breaches do occur, they are lateral.

LEVEL OF EVIDENCE: 3

Comparative Biomechanical Analysis of Anterior Lumbar Interbody Fusion and Bilateral Expandable Transforaminal Lumbar Interbody Fusion Cages: A Finite Element Analysis Study

BACKGROUND

Expandable transforaminal lumbar interbody fusion (TLIF) cages could offer an alternative to anterior lumbar interbody fusion (ALIF). Bilateral cage insertion enhances endplate coverage, potentially improving stability and fusion rates and maximizing segmental lordosis. This study aims to compare the biomechanical properties of bilateral expandable TLIF cages to ALIF cages using finite element modeling.

METHODS

We used a validated 3-dimensional finite element model of the lumbar spine. ALIF and TLIF cages were created based on available product data. Our focus was on analyzing spinal motion in the sagittal plane, evaluating forces transmitted through the vertebrae, and comparing an ALIF model with various TLIF cage models.

RESULTS

The largest TLIF cage model exhibited a 407.9% increase in flexion motion and a 42.1% decrease in extension motion compared with the ALIF cage. The second largest TLIF cages resulted in more flexion motion and less extension motion compared with ALIF, while smaller cages were inferior to ALIF. ALIF cages were associated with increased adjacent segment motion compared with TLIF cages, primarily in extension. Endplate stress analysis revealed higher stress in the ALIF cage model with a more uniform stress distribution.

CONCLUSION

ALIF cages excel in stabilizing L5 to S1 during flexion, while largest TLIF cages offer superior stability in extension. Large bilateral TLIF cages may provide biomechanical stability comparable to ALIF, especially in extension and could potentially reduce the risk of adjacent segment disease with lower adjacent segment motion.

LEVEL OF EVIDENCE: 5

Retrospective analysis of medium-term outcomes following anterior lumbar interbody fusion surgery performed in a tertiary spinal surgical centre

INTRODUCTION

Anterior lumbar interbody fusion (ALIF) can treat spondylolisthesis, degenerative disc disease and pseudoarthrosis. This approach facilitates complete discectomy, disc space distraction, indirect decompression of neural foramina and placement of large interbody devices. Several intra- and postoperative complications can be attributed to the anterior approach: vascular/visceral injury, hypogastric plexus injury and urogenital consequences. Spine-specific complications include implant migration, graft failure, pseudoarthrosis and persistent symptomology.

METHODS

This retrospective study reviewed patient demographics, medium-term outcomes and complication rates following ALIF surgery performed over a 5-year period. A total of 110 consecutive patients had undergone ALIF surgery at a single tertiary spinal centre. The database was reviewed with a primary outcome of identifying postoperative 90-day complications and whether a revision anterior operation was required after primary ALIF.

RESULTS

No patients required revision anterior operation after their primary ALIF surgery by final follow-up. Out of 110 patients, 11 (10%) recorded a complication attributed to the anterior stage of their operation within 90 days.

CONCLUSIONS

Our 90-day complication rate of 10% lies within the 2.6% acute complication and 40% overall complications rates described in previous literature. The risk of vascular/visceral injury is significant (3%) and we recommend that ALIF be performed as a dual surgeon procedure with a vascular-trained access surgeon accompanying the spinal surgeon. ALIF is a valid revision surgical option for failed posterior approaches leading to complications such as pseudoarthrosis. In our sample, 89% of patients were managed with posterior fixation to augment the anterior fusion as, biomechanically, this is a proven construct.

Pacific Spine and Pain Society (PSPS) Evidence Review of Surgical Treatments for Lumbar Degenerative Spinal Disease: A Narrative Review

INTRODUCTION

Interventional treatment options for the lumbar degenerative spine have undergone a significant amount of innovation over the last decade. As new technologies emerge, along with the surgical specialty expansion, there is no manuscript that utilizes a review of surgical treatments with evidence rankings from multiple specialties, namely, the interventional pain and spine communities. Through the Pacific Spine and Pain Society (PSPS), the purpose of this manuscript is to provide a balanced evidence review of available surgical treatments.

METHODS

The PSPS Research Committee created a working group that performed a comprehensive literature search on available surgical technologies for the treatment of the degenerative spine, utilizing the ranking assessment based on USPSTF (United States Preventative Services Taskforce) and NASS (North American Spine Society) criteria.

RESULTS

The surgical treatments were separated based on disease process, including treatments for degenerative disc disease, spondylolisthesis, and spinal stenosis.

CONCLUSIONS

There is emerging and significant evidence to support multiple approaches to treat the symptomatic lumbar degenerative spine. As new technologies become available, training, education, credentialing, and peer review are essential for optimizing patient safety and successful outcomes.

Primary anterior lumbar interbody fusion, with and without posterior instrumentation: a 1,377-patient cohort from a multicenter spine registry

BACKGROUND CONTEXT

Lumbar interbody instrumentation techniques are common and effective surgical options for a variety of lumbar degenerative pathologies. Anterior lumbar interbody fusion (ALIF) has become a versatile and powerful means of decompression, stabilization, and reconstruction. As an anterior only technique, the integrity of the posterior muscle and ligaments remain intact. Adding posterior instrumentation to ALIF is common and may confer benefits in terms of higher fusion rate but could contribute to adjacent segment degeneration due to additional rigidity. Large clinical studies comparing stand-alone ALIF with and without posterior supplementary fixation (ALIF+PSF) are lacking.

PURPOSE

To compare rates of operative nonunion and adjacent segment disease (ASD) in ALIF with or without posterior instrumentation.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Adult patients (≥18 years old) who underwent primary ALIF for lumbar degenerative pathology between levels L4 to S1 over a 12-year period. Exclusion criteria included trauma, cancer, infection, supplemental decompression, noncontiguous fusions, prior lumbar fusions, and other interbody devices.

OUTCOME MEASURES

Reoperation for nonunion and ASD compared between ALIF only and ALIF+PSF.

METHODS

Reoperations were modeled as time-to-events where the follow-up time was defined as the difference between the primary ALIF procedure and the date of the outcome of interest. Crude cumulative reoperation probabilities were reported at 5-years follow-up. Multivariable Cox proportional hazard regression was used to evaluate risk of operative nonunion and for ASD adjusting for patient characteristics.

RESULTS

The study consisted of 1,377 cases; 307 ALIF only and 1070 ALIF+PSF. Mean follow-up time was 5.6 years. The 5-year crude nonunion incidence was 2.4% for ALIF only and 0.5% for ALIF+PSF; after adjustment for covariates, a lower operative nonunion risk was observed for ALIF+PSF (HR=0.22, 95% CI=0.06-0.76). Of the patients who are deemed potentially suitable for ALIF alone, one would need to add posterior instrumentation in 53 patients to prevent one case of operative nonunion at a 5-year follow-up (number needed to treat). Five-year operative ASD incidence was 4.3% for ALIF only and 6.2% for ALIF+PSF; with adjustments, no difference was observed between the cohorts (HR=0.96, 95% CI=0.54-1.71).

CONCLUSIONS

While the addition of posterior instrumentation in ALIFs is associated with lower risk of operative nonunion compared with ALIF alone, operative nonunion is rare in both techniques (<5%). Accordingly, surgeons should evaluate the added risks associated with the addition of posterior instrumentation and reserve the supplemental posterior fixation for patients that might be at higher risk for operative nonunion. Rates of operative ASD were not statistically higher with the addition of posterior instrumentation suggesting concern regarding future risk of ASD perhaps should not play a role in considering supplemental posterior instrumentation in ALIF.

Risk Factors for Blood Transfusions in Elective Single-Level Anterior Lumbar Interbody Fusion for Degenerative Conditions

Background

ALIF (anterior lumbar interbody fusion) and other spinal fusion surgeries are among the most common orthopaedic procedures requiring blood transfusions. However, blood transfusions have been associated with various complications, including adverse reactions and infections. The present study aims to identify independent risk factors for blood transfusions in patients undergoing single-level ALIF specifically to better identify high risk patients and optimize perioperative management.

Methods

All patients who had undergone single-level ALIF patients for the treatment of degenerative spinal conditions, excluding traumatic, pathologic, and infectious etiologies, were identified by querying a multi-institutional surgical registry from 2005 to 2018. Multi-level fusions, PLIF/TLIF, and posterior procedures were also excluded. Mann-Whitney-U-Tests were used to analyze continuous variables, while Fisher's-Exact-Tests/Bonferroni-Corrected-Tests were used for categorical variables. Multivariate logistic regression analysis with alternating backward stepwise elimination and forward entry was implemented to identify significant predictors for blood transfusions within 72 hours after incision. The predicted probabilities were used in post-regression diagnostics to generate a Receiver Operating Characteristic (ROC) curve to assess model performance.

Results

4,792 single-level ALIF patients met inclusion criteria - 183 (3.82%) had received blood transfusions within 72 hours after incision and 4,609 (96.18%) had not. Age ≥60 years (OR 1.954, p<0.001), preoperative transfusions (OR 33.758, p=0.023), extended operative times (≥197.0 minutes; 75th percentile) (OR 4.645, p<0.001), ASA≥3 (OR 1.395, p<0.001) and preoperative hematocrit levels (Hct) 30.00-37.99 (OR 1.562, p=0.016) and Hct <30.00 (OR 6.334, p<0.001) were shown to be significant independent risk factors for perioperative blood transfusions. The area under the ROC curve (AUROC; C-statistic) was 0.759 (p<0.001), indicating relatively strong discriminatory ability/predictability of the final model.

Conclusion

Several independent risk factors including age ≥60 years, preoperative blood transfusions and extended operative times increased risk for blood transfusion following single-level ALIF. The present study aims to help surgeons identify high-risk patients to better communicate postoperative expectations and optimize patients to reduce the risk of transfusions and secondary complications. Level of Evidence: III.

Stand-alone ALIF versus TLIF in patients with low back pain - A propensity-matched cohort study with two-year follow-up

Introduction

Instrumented lumbar fusion by either the anterior or transforaminal approach has different advantages and disadvantages. Few studies have compared PatientReported Outcomes Measures (PROMs) between stand-alone anterior lumbar interbody fusion (SA-ALIF) and transforaminal lumbar interbody fusion (TLIF).

Research question

This is a register-based dual-center study on patients with severe disc degeneration (DD) and low back pain (LBP) undergoing single-level SA-ALIF or TLIF. Comparing PROMs, including disability, quality of life, back- and leg-pain and patient satisfaction two years after SA-ALIF or TLIF, respectively.

Material and methods

Data were collected preoperatively and at one and two-year follow-up. The primary outcome was Oswestry Disability Index (ODI). The secondary outcomes were patient satisfaction, walking ability, visual analog scale (VAS) scores for back and leg pain, and quality of life (QoL) measured by the European Quality of Life-5 Dimensions (EQ-5D) index score. To reduce baseline differences between groups, propensity-score matching was employed in a 1:1 fashion.

Results

92 patients were matched, 46 S A-ALIF and 46 TLIF. They were comparable preoperatively, with no significant difference in demographic data or PROMs (P > 0.10). Both groups obtained statistically significant improvement in the ODI, QoL and VAS-score (P < 0.01), but no significant difference was observed (P = 0.14). No statistically significant differences in EQ-5D index scores (P = 0.25), VAS score for leg pain (P = 0.88) and back pain (P = 0.37) at two years follow-up.

Conclusion

Significant improvements in ODI, VAS-scores for back and leg pain, and EQ-5D index score were registered after two-year follow-up with both SA-ALIF and TLIF. No significant differences in improvement.

How to manage a ureteral injury after anterior lumbar spine interbody fusion surgery

BACKGROUND

Anterior lumbosacral interbody fusion (ALIF) surgery is a predominant approach used in various indications such as treating discogenic back pain, spondylolisthesis, degenerative lumbar scoliosis, intervertebral foraminal stenosis, or spondylolysis. In comparison with posterior conventional approach, ALIF surgery has several advantages: direct access to the spine without muscle dissection, reduced blood loss, decreased postoperative pain, and improved fusion rates. Rare complications following ALIF surgery need to be reported, therefore the authors present an uncommon case of a ureteral injury diagnosed early after surgery and its management.

MANAGEMENT OF A URINOMA

Herein, we present a case of a 35-year-old man who presented with abnormal abdominal pains 4 days after ALIF surgery. He was diagnosed with a distal left iatrogenic ureteral fistula on a contrast enhanced CT. After the initial endoscopic approach with double J stent and urinary catheter drainage insertion had failed, the injury was finally treated with ureterovesical reimplantation. At the last follow-up, the patient did well without any clinical or biological urinary sequelae after this grade IIIb complication on the Clavien Dindo Scale.

CONCLUSION

Although ureteral lesions during ALIF surgery are extremely uncommon, surgeons must be cautious when dissecting the retroperitoneal area. A methodical identification of the ureter might guarantee the security of each surgery, especially for patients who have undergone previous abdominal interventions.

New diagnosis of conversion disorder following anterior lumbar interbody fusion: a case report

Neurologic deficit after lumbar spine surgery is a rare and serious complication that must be promptly diagnosed and treated to avoid long-term neurologic disability. Anterior lumbar interbody fusion (ALIF) is an effective technique for the treatment of recurrent disc herniation and lumbar disc degeneration. This case report describes a 20-year-old female with L5-S1 recurrent disc herniation and lumbar degeneration. She underwent an L5-S1 ALIF complicated by post-operative lower left extremity paralysis. Revision surgery with downsizing of the ALIF cage was performed with normal neuromonitoring throughout the procedure. The patient displayed persistent post-operative neurologic deficits despite no evidence of central or foraminal compression. Patient was later diagnosed with conversion disorder by neurology during her hospitalization. This case report presents the initial diagnosis of conversion disorder after a routine ALIF procedure, which led to surgical re-exploration and prolonged inpatient hospital stay. Psychiatric diagnoses must be considered when neurologic deficits are present with no apparent organic cause.

Reduction of spondylolisthesis and restoration of lumbar lordosis after anterior lumbar interbody fusion (ALIF)

BACKGROUND

Anterior lumbar interbody fusion (ALIF) is a well-established surgical treatment option for various diseases of the lumbar spine, including spondylolisthesis. This study aimed to evaluate the postoperative correction of spondylolisthesis and restoration of lumbar and segmental lordosis after ALIF.

METHODS

Patients with spondylolisthesis who underwent ALIF between 2013 and 2019 were retrospectively assessed. We assessed the following parameters pre-and postoperatively (6-months follow-up): Visual Analogue Scale (VAS) for pain, Oswestry Disability Index (ODI), lumbar lordosis (LL), segmental lordosis (SL), L4/S1 lordosis, and degree of spondylolisthesis.

RESULTS

96 patients were included. In 84 cases (87.50%), additional dorsal instrumentation was performed. The most frequent diagnosis was isthmic spondylolisthesis (73.96%). VAS was reduced postoperatively, from 70 to 40, as was ODI (50% to 32%). LL increased from 59.15° to 64.45°, as did SL (18.95° to 28.55°) and L4/S1 lordosis (37.90° to 44.00°). Preoperative spondylolisthesis was 8.90 mm and was reduced to 6.05 mm postoperatively. Relative spondylolisthesis was 21.63% preoperatively and 13.71% postoperatively. All clinical and radiological improvements were significant (all p < 0.001). No significant difference considering the lordosis values nor spondylolisthesis was found between patients who underwent ALIF surgery without dorsal instrumentation and patients who received additional dorsal instrumentation. Venous laceration was the most frequent complication (10.42%).

CONCLUSIONS

With ALIF, good clinical results and safe and effective reduction of spondylolisthesis and restoration of lordosis can be achieved. Additional dorsal instrumentation does not significantly affect postoperative lordosis or spondylolisthesis. Individual vascular anatomy must be reviewed preoperatively before considering ALIF.

Influence of Preoperative Disability on Clinical Outcomes in Patients Undergoing Anterior Lumbar Interbody Fusion

BACKGROUND

Few studies have examined the influence of preoperative disability through the Oswestry Disability Index (ODI) on clinical outcomes in patients undergoing anterior lumbar interbody fusion (ALIF).

METHODS

Patients undergoing ALIF were separated into 2 groups based on ODI<41 (lower disability) versus ODI≥41% (higher disability). Patient-reported outcomes (PROs) were collected at preoperative and postoperative 6-week/12-week/6-month/1-year/2-year time points. Physical function PROs were Patient-Reported Outcomes Measurement Information System Physical Function and 12-item Short Form Physical Component Score. Mental function PROs were 12-item Short Form Mental Component Score and Patient Health Questionnaire-9. Pain PROs were visual analog scale back and visual analog scale leg. ODI was the disability PRO.

RESULTS

A total of 148 patients were identified, with 52 patients with lower disability. Higher disability patients demonstrated significant improvement in mental function (P ≤ 0.010, all). Lower disability patients demonstrated superior postoperative PROs in physical function, mental function, back pain, and disability outcomes (P ≤ 0.034, all). Minimum clinically important difference achievement rates for lower disability patients were higher for back pain and lower for mental function and disability outcomes (P ≤ 0.041, all).

CONCLUSIONS

Independent of preoperative disability, patients undergoing ALIF reported significant postoperative improvement in physical function, pain, and disability outcomes. Patients with lower preoperative disability continued to report superior PROs in mental function, back pain, and disability postoperatively. Minimum clinically important difference achievement rates for lower disability patients were higher for back pain and lower in mental function and disability outcomes. Patients undergoing ALIF with higher preoperative disability may experience greater clinically meaningful improvement in mental function and disability.

Trends in Reimbursement and Approach Selection for Lumbar Arthrodesis

BACKGROUND

Changes in reimbursement policies have been demonstrated to correlate with clinical practice.

OBJECTIVE

To investigate trends in physician reimbursement for anterior, posterior, and combined anterior/posterior (AP) lumbar arthrodesis and relative utilization of AP.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Project registry for anterior, posterior, and AP lumbar arthrodeses during 2010 and 2020. Work relative value units per operative hour (wRVUs/h) were calculated for each procedure. Trends in reimbursement and utilization of the AP approach were assessed with linear regression. Subgroup analyses of age and underlying pathology of AP arthrodesis were also performed.

RESULTS

During 2010 and 2020, AP arthrodesis was associated with significantly higher average wRVUs/h compared with anterior and posterior arthrodesis (AP = 17.4, anterior = 12.4, posterior = 14.5). The AP approach had a significant yearly increase in wRVUs/h (coefficient = 0.48, P = .042), contrary to anterior (coefficient = -0.01, P = .308) and posterior (coefficient = -0.13, P = .006) approaches. Utilization of AP approaches over all arthrodeses increased from 7.5% in 2010 to 15.3% in 2020 (yearly average increase 0.79%, P < .001). AP fusions increased significantly among both degenerative and deformity cases (coefficients 0.88 and 1.43, respectively). The mean age of patients undergoing AP arthrodesis increased by almost 10 years from 2010 to 2020. Rates of major 30-day complications were 2.7%, 3.1%, and 3.5% for AP, anterior, and posterior arthrodesis, respectively.

CONCLUSION

AP lumbar arthrodesis was associated with higher and increasing reimbursement (wRVUs/h) during the period 2010 to 2020. Reimbursement for anterior arthrodesis was relatively stable, while reimbursement for posterior arthrodesis decreased. The utilization of the combined AP approach relative to the other approaches increased significantly during the period of interest.

Anterior spinal fusion (ALIF/OLIF/LLIF) with lumbosacral transitional vertebra: A systematic review and proposed treatment algorithm

•Key anterior approaches differences in LSTV include vascular (aortic bifurcation/iliocaval confluence), muscular (psoas) and osseus anatomy (inter-crestal tangent/pubic symphysis), when compared to non-LSTV.•There are increased surgical deviations but not significantly greater complications for anterior approaches in LSTV.•Vascular awareness while accessing L45 will be in the presence of a more cephalad ABF and ICC with sacralized L5, and access to the deeper L56 level will be in the presence of a more caudal ABF and ICC in lumbarized S1.

Location variance of the great vessels while undergoing side-bend positioning changes during lateral interbody fusion

Background

Minimally invasive lateral lumbar interbody fusion (LLIF) is an increasingly popular surgical technique that facilitates minimally invasive exposure, attenuated blood loss, and potentially improved arthrodesis rates. However, there is a paucity of evidence elucidating the risk of vascular injury associated with LLIF, and no previous studies have evaluated the distance from the lumbar intervertebral space (IVS) to the abdominal vascular structures in a side-bend lateral decubitus position. Therefore, the purpose of this study is to evaluate the average distance, and changes in distance, from the lumbar IVS to the major vessels from supine to side-bend right and left lateral decubitus (RLD and LLD) positions simulating operating room positioning utilizing magnetic resonance imaging (MRI).

Methods

We independently evaluated lumbar MRI scans of 10 adult patients in the supine, RLD, and LLD positions, calculating the distance from each lumbar IVS to adjacent major vascular structures.

Results

At the cephalad lumbar levels (L1-L3), the aorta lies in closer proximity to the IVS in the RLD position, in contrast to the inferior vena cava (IVC), which is further from the IVS in the RLD. At the L3-S1 vertebral levels, the right and left common iliac arteries (CIA) are both further from the IVS in the LLD position, with the notable exception of the right CIA, which lies further from the IVS in the RLD at the L5-S1 level. At both the L4-5 and L5-S1 levels, the right common iliac vein (CIV) is further from the IVS in the RLD. In contrast, the left CIV is further from the IVS at the L4-5 and L5-S1 levels.

Conclusion

Our results suggest that RLD positioning may be safer for LLIF as it affords greater distance away from critical venous structures, however, surgical positioning should be assessed at the discretion of the spine surgeon on a patient-specific basis.

Minimally Invasive Transforaminal versus Anterior Lumbar Interbody Fusion in Patients Undergoing Revision Fusion: Clinical Outcome Comparison

OBJECTIVE

We aim to compare perioperative/postoperative clinical outcomes between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and anterior lumbar interbody fusion (ALIF) in patients presenting for revision surgery.

METHODS

A retrospective database was reviewed for procedures between November 2005 and December 2021. Revision MIS-TLIF/ALIFs were included, whereas primary fusions or diagnosis of infection/malignancy/trauma were excluded. Patients were grouped into MIS-TLIF/ALIF cohorts. Preoperatively/postoperatively collected patient-reported outcome measures (PROMs) included visual analog scale back/leg score, Oswestry Disability Index, Patient-Reported Outcome Measurement Information System-Physical Function (PROMIS-PF), and Short-Form 12-Item Survey Mental/Physical Composite Scores.

RESULTS

A total of 164 patients were eligible, with 84 patients in the MIS-TLIF cohort. The presence of degenerative spondylolisthesis and central stenosis, narcotic consumption on postoperative day 0/1, and postoperative urinary retention rates was greater in the MIS-TLIF cohort (P ≤ 0.036, all). Preoperative PROMs between cohorts did not significantly differ. Significantly favorable postoperative PROM scores were shown in the MIS-TLIF cohort with PROMIS-PF at 12 weeks/6 months (P ≤ 0.033, all). Most patients in both cohorts achieved overall minimum clinically important difference for visual analog scale back/leg score, Oswestry Disability Index, Short-Form 12-Item Survey Physical Composite Score, and PROMIS-PF. No differences were noted between cohorts within rates of MCID achievement.

CONCLUSIONS

Patients undergoing revision fusion via MIS-TLIF or ALIF reported similar 1-year postoperative mean outcomes and rates of meaningful clinical achievement for physical function, mental health, disability, and back/leg pain. However, patients undergoing revision MIS-TLIF reported improved physical function at 12 weeks and 6 months. Perioperatively, patients undergoing revision MIS-TLIF were noted to consume significantly greater quantities of narcotics.

A Modified Spinal Reconstruction Method Reduces Instrumentation Failure in Total En Bloc Spondylectomy for Spinal Tumors

Introduction

Long-term spinal stability after total en bloc spondylectomy (TES) is challenging. The aim of this study was to examine whether the new method could reduce the incidence of instrumentation failure (IF).

Methods

We retrospectively compared 116 patients with spinal tumors who underwent TES between 2010 and 2019 and were followed up for >1 year. IF, cage subsidence, and complications were evaluated. Propensity score matching between conventional and new method groups was performed for age, sex, body mass index, preoperative radiotherapy, number of resected vertebrae, number of instrumented vertebrae, tumor level, and follow-up period. There were 25 cases each in the conventional and new method groups. The conventional method used a titanium mesh cage for anterior reconstruction and 5.5-mm-diameter titanium alloy rods for posterior fixation. The new method used a more robust cage for anterior reconstruction, bone grafting was performed around the cage, and 6.0-mm-diameter cobalt chromium rods were used for posterior fixation. We compared the incidence of IF and cage subsidence after TES between the conventional and new method groups.

Results

While 5 out of 25 patients (20.0%) in the conventional method group experienced IF, none from the new method group experienced IF. Three-year implant survival rates were 87.3% in the conventional and 100% in the new method groups. The new method group had a significantly higher implant survival rate (p<0.01). Cage subsidence was observed in 11 of 25 (44/0%) patients in the conventional method and 1 of 25 (4.0%; significantly lower, p<0.05) in the new method group.

Conclusions

The new reconstruction method significantly reduced IF incidence in patients with TES.

MRI changes of adjacent segments after transforaminal lumbar interbody fusion (TLIF) and foraminal endoscopy: A case-control study

BACKGROUND

Intervertebral foramen endoscopy has developed rapidly, but compared with transforaminal lumbar interbody fusion (TLIF), the progress of degeneration is unknown. We aim to compare the changes of intervertebral disc and intervertebral foramen in adjacent segments after TLIF and endoscopic discectomy for patients with lumbar disc herniation (LDH).

METHODS

From 2014 to 2017, 87 patients who were diagnosed with single-level LDH and received surgery of TLIF (group T, n = 43) or endoscopic discectomy (group F, n = 44) were retrospectively analyzed. X-ray, MRI, CT and clinical symptoms were recorded before operation and at the last follow-up (FU). The neurological function was originally evaluated by the Japanese Orthopaedic Association (JOA) scores. Radiological evaluation included the height of intervertebral space (HIS), intervertebral foramen height (FH), intervertebral foramen area (FA), lumbar lordosis (CA) and intervertebral disc degeneration Pfirrmann scores.

RESULTS

There was no significant difference in baseline characteristics, JOA improvement rate, reoperation rate and complications between the two groups. The age, average blood loss, average hospital stays and average operation time in group F were lower than those in group T. During the last FU, HIS, CA and FA decreased in both groups, and the changes in group T were more significant than those in group F (P < .05). There was no significant difference in FH changes between the two groups (P > .05).

CONCLUSION

Both TLIF and endoscopic surgery can achieve good results in the treatment of LDH, but the risk of lumbar disc height loss and intervertebral foramina reduction in the adjacent segment after endoscopic surgery is lower.

Perioperative and Radiographic Outcomes Between Single-Position Surgery (Lateral Decubitus) and Dual-Position Surgery for Lateral Lumbar Interbody Fusion and Percutaneous Pedicle Screw Fixation: Meta-Analysis

OBJECTIVE

Lateral lumbar interbody fusion (LLIF) and percutaneous posterior screw fixation (PPSF) techniques is used to treat degenerative lumbar pathologies. Dual-position (DP) lumbar surgery involves repositioning the patient from the supine or lateral decubitus position to prone for posterior fixation. Single-position (SP) lumbar surgery is commonly performed nowadays, a minimally invasive alternative performed entirely from the lateral decubitus position. However, controversy still exists. This meta-analysis aimed to compare perioperative outcomes between SP lumbar surgery and DP lumbar surgery for LLIF and PPSF.

METHODS

We conducted this meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and searched Medline and Scopus from inception to November 11, 2021, for relevant studies.

RESULTS

Six studies were identified, which contained totals of 502 and 447 patients in the SP and DP groups, respectively. The unstandardized mean difference in operative time, length of hospital stay, intraoperative blood loss, radiation doses, lumbar lordosis, and pelvic incidence-lumbar lordosis mismatch were -86.1 (95% confidence interval [CI] -149.2 to -23.1) minutes, -1.6 (95% CI -2.4 to -0.9) days, -55.6 (95% CI -127.5 to 16.2) mL, -30.3 (95% CI -80.5 to 19.8) mGy, 1.34 (95% CI -1.17 to 3.86) degrees, and -4.06 (95% CI -5.65 to -2.47) lower in SP when compared with DP. The chances of having complications and reoperations in SP were 0.75 (95% CI 0.49-1.14) and 0.77 (95% CI 0.44-1.36) times, respectively, compared with the DP group. No significant differences were found for intraoperative blood loss, radiation dose, lumbar lordosis, complications, and reoperations between the 2 groups.

CONCLUSIONS

This meta-analysis found that SP have lower operative time and length of hospital stay compared with DP LLIF and PPSF. However, no differences in intraoperative blood loss, radiation dose, radiographic change, complications, and reoperation rates were found.

The Use of a Transforaminal Lumbar Interbody Fusion (TLIF) Cage Following Inadequate Access to the Disc Space During an Anterior Lumbar Interbody Fusion Procedure

Non-specific lower back pain caused by degenerative lumbar disease, such as disc and facet joint degeneration or spondylolisthesis, significantly impairs quality of life of patients and is associated with higher pain scores and reduced function. Patients that fail to respond to conservative treatment may require surgical intervention, such as lumbar interbody fusion (LIF). Compared to other approaches, an anterior approach to lumbar interbody fusion (ALIF) has advantages regarding efficacy of fusion, visualization of relevant anatomy, and a larger allowable size of the interbody fusion device. An anterior approach’s main biomechanical advantage includes the ability to restore sagittal alignment, achieve indirect decompression, and provide increased anterior column support. Complications of anterior interbody fusion are mostly approach related and include vascular injury or visceral injury. However, the anterior anatomy can make the placement of an interbody device challenging. In the case reported here, an ALIF procedure was complicated by immobile iliac vessels leaving a small window to place the interbody cage. Continuing with the anterior approach was opted, but with the oblique placement of a cage traditionally used in transforaminal lumbar interbody fusion (TLIF) procedures.

Anterior lumbar interbody fusion: single institutional review of complications and associated variables

BACKGROUND CONTEXT

As more patients undergo anterior lumbar interbody fusion (ALIF) procedures and more devices are created for that purpose, it is important to understand the complications that can arise and the variables that mitigate risk for major and minor complications.

PURPOSE

To assess complication rates after ALIF with or without posterior instrumentation and variables associated with increased likelihood of postoperative complications. We aim to provide this data as benchmarking to improve patient safety and surgical care.

STUDY DESIGN

A single-center retrospective cohort study.

PATIENT SAMPLE

All adult patients who underwent ALIF between 2017 and 2019 was performed OUTCOME MEASURES: Post-operative major and minor complications were evaluated.

METHODS

Complications were recorded and presented as percentages. Patient demographics, perioperative, and postoperative data were also collected and analyzed between patients who had no complications and those that had any complication. Subgroup analysis of surgical complications were performed by nonparametric Chi-square tests. Continuous variables were compared using Mann-Whitney U tests.

RESULTS

Ninty-five of three hundred sixty-two (26.2%) of patients experienced a minor or major complication. Among the most common complications found were surgical site infections (5.8%), neurological complications (4.1%), vascular complications (3.6%), and urinary tract infections (3.3%). Patients undergoing ALIF alone with post-operative complications had higher mean age, higher BMI, higher ASA status, and experienced higher estimated blood loss. Patients undergoing ALIF and posterior instrumentation with post-operative complications were more likely to have diabetes and had a higher ASA status. Patients with any complications from both groups had longer length of stay, discharge to a non-home setting and were more likely to be readmitted or return to the operating room.

CONCLUSION

Our study reveals variables associated with complications at our institution, including age of the patient, BMI, and ASA status leading to higher complications and greater LOS, higher readmission rates, and disposition to skilled facilities.

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.

THORACOLUMBAR FUSION IN THE UNIFIED HEALTH SYSTEM: PRE-COVID-19 TEMPORAL

ABSTRACT Objective: To evaluate the temporal trends of thoracolumbar fusion procedures performed by the United Health System in Brazil from 2009 to 2019. Methods: This was an observational ecological study based on data collected from the information systems under the aegis of DATASUS, especially the Hospital Information System, which manages the Hospital Admission Authorizations (Autorizações de Internação Hospitalar - AIHs). All patients who had undergone the procedures of interest, that is, elective and emergency short and long thoracolumbar arthrodeses, were included. The temporal trends of the procedures performed in Brazil and in its five regions were calculated using polynomial regression. Results: The temporal trend of elective thoracolumbar arthrodesis decreased, while that of emergency arthrodesis increased, with the peak in 2015, followed by a marked decline. Short fusions were more frequent in both elective and emergency modalities, and the South and Central-West Regions had the highest indices of procedures per million inhabitants during the entire 2009 to 2019 period. Conclusions: The temporal trends of thoracolumbar fusions performed by SUS have decreased over the last decade, a phenomenon which may be explained by the growing criticism of indications of the procedure in the current literature. Level of evidence III; Retrospective Comparative Study.

Outcomes of anterior vs. posterior approach to single-level lumbar spinal fusion with interbody device: An analysis of the nationwide inpatient sample

BACKGROUND

Interbody devices have revolutionized lumbar spinal fusion surgery by improving mechanical stability and maximizing fusion potential. Several approaches for interbody fusion exist with two of the most common being anterior lumbar interbody fusion (ALIF) and posterior lumbar interbody fusion (PLIF). This study aims to compare patient data, hospital outcomes, and post-operative complications between an anterior vs. posterior approach to lumbar interbody fusion.

METHODS

This retrospective cohort study utilized the Nationwide Inpatient Sample (NIS) and International Classification of Diseases, 10th edition (ICD10) codes to identify patients (18 +) from 2016 to 2018 who underwent lumbar interbody fusion under an anterior or posterior approach. Patients missing identifiers were excluded from this study. Patients were further investigated by demographic data and the presence of comorbidities. Hospital outcome data was investigated by length of stay (LOS), total hospital charges, mortality, and post-operative complications.

RESULTS

373,585 patients were included in this study. 257,975 (69%) underwent fusion via a posterior approach, and 115,610 (31%) via an anterior approach. Patients undergoing posterior approach were found to have a greater number of comorbidities than anterior (3.5 vs. 2, respectively, p = <0.001). The posterior approach was associated with decreased LOS (3.59 vs 4.19 days, p = <0.0001) and decreased total hospital charges ($141,700 vs $211,015, p = <0.0001). A posterior approach was found to have lower rates of post-operative complications. For the anterior approach cohort, tobacco dependence (OR=1.31 [1.20-1.42, p = <0.001], diabetes (OR=2.41 [2.33-2.49, p = <0.001], and osteoporosis (OR=1.42 [1.30-1.54, p = <0.001] were found to be significant independent predictors of post-operative pseudoarthrosis. Obesity (OR=1.28 [1.14-1.42, p = <0.001], tobacco dependence (OR=1.48 [1.40-1.56, p = <0.001], diabetes (OR=2.21 [2.10-2.32, p = <0.001], congestive heart failure (OR=1.20 [1.01-1.39, p = 0.04], and osteoporosis (OR=1.65 [1.55-1.75, p = <0.001], were found to be independent predictors of post-operative pseudoarthrosis in the posterior cohort.

CONCLUSIONS

Patients who underwent the anterior approach suffered from increased hospital charges, length of stay, and increased risk of post-operative complications including mortality, wound dehiscence, hematoma/seroma, and pseudoarthrosis. Comorbid disease plays a significant role in the outcome of successful fusion with variable effect depending on the surgical approach. Increasing due diligence in patient selection should be considered when choosing an approach in pre-operative planning.

Comparison of surgical outcomes between oblique lateral interbody fusion (OLIF) and anterior lumbar interbody fusion (ALIF)

OBJECTIVE

Although oblique lateral interbody fusion (OLIF) utilizes the similar approach in anterior lumbar interbody fusion (ALIF), OLIF is essentially a lateral lumbar interbody fusion (LLIF). Therefore, OLIF may have advantages in LLIF that the lateral cage can achieve greater restoration of the disc height and angle. We aimed to compared the surgical outcomes between OLIF and ALIF.

METHODS

This study involved 47 consecutive patients who underwent a single-level OLIF and 45 consecutive patients who underwent a single-level ALIF at L2-L5 levels. Radiological measurements included the changes of anterior/posterior disc height, coronal/sagittal disc angle, foramen cross-sectional area (CSA), cage position from the anterior margin of the lower vertebra, fusion rate, and cage subsidence using the serial radiographs and computed tomography preoperatively and at the postoperative 1-year follow-up. Clinical outcomes were assessed by visual analog scale (VAS) for back/leg pain, Oswestry disability index (ODI), and the occurrence of perioperative complications.

RESULTS

The baseline radiological and clinical parameters were similar between the OLIF and ALIF groups (all P > 0.05). At postoperative 1 year, the mean anterior disc height was higher in the OLIF group than the ALIF group (11.4 ± 1.9 mm vs. 9.6 ± 2.6 mm, P = 0.021). The mean sagittal disc angle was also greater in the OLIF group than the ALIF group (10.9 ± 4.4° vs. 8.9 ± 5.8°, P < 0.001). The mean cage position was 5.8 ± 2.1 mm in the OLIF group and 8.7 ± 2.3 mm in the ALIF group (P <  0.001). There was no difference in the postoperative changes of coronal disc angles, foramen CSA, fusion rate, cage subsidence, VAS for back/leg pain, ODI, and the occurrence of perioperative complications between the OLIF and ALIF groups (all P > 0.05).

CONCLUSIONS

OLIF showed a greater increase in disc height and segmental lordosis than ALIF with comparable complications. OLIF is a meaningful progress from ALIF.

Expandable Cage Technology-Transforaminal, Anterior, and Lateral Lumbar Interbody Fusion

This review of the literature will focus on the indications, surgical techniques, and outcomes for expandable transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and lateral lumbar interbody fusion (LLIF) operations. The expandable TLIF cage has become a workhorse for common degenerative pathology, whereas expandable ALIF cages carry the promise of greater lordotic correction while evading the diseased posterior elements. Expandable LLIF cages call upon minimally invasive techniques for a retroperitoneal, transpsoas approach to the disc space, obviating the need for an access surgeon and decreasing risk of injury to the critical neurovascular structures. Nuances between expandable and static cages for all 3 TLIF, ALIF, and LLIF operations are discussed in this review.

Retroperitoneal Exposure of the Anterior Lumbar Spine

BACKGROUND

Anterior lumbar spine procedures such as anterior lumbar interbody fusion (ALIF) are used commonly to treat multiple pathologies, including pseudoarthrosis and degenerative disk disease. It is generally a safe and effective procedure, but an anterior approach to the lumbar spine requires critical navigation of the surgical window to avoid delicate structures. An operative technique should maximize the exposure without an increased risk of iatrogenic injury.

OBJECTIVE

To describe in detail a retroperitoneal exposure of the anterior lumbar spine.

METHODS

This surgical approach is a unique variation of standard anterior lumbar spine exposure techniques. This technique is described and illustrated in detail with an accompanying Supplemental Digital Content: video. Institutional Review Board (IRB) approval was not required because this is a variation of current techniques. Patient consent was obtained for the procedure and use of operative pictures and videos.

RESULTS

Precise details of the technique are described. The surgical video demonstrates the technique for the L5-S1 ALIF approach.

CONCLUSION

This technique is a novel variation of the standard retroperitoneal exposure of the anterior lumbar spine. The incision placement, size, and dynamic blunt retraction of this approach limit tissue disruption and provide an efficient exposure that has not been previously described in the literature.

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.

Postoperative adverse events secondary to iatrogenic vascular injury during anterior lumbar spinal surgery

BACKGROUND

Anterior lumbar spine surgery (ALSS) requires mobilization of the great vessels, resulting in a high risk of iatrogenic vascular injury (VI). It remains unclear whether VI is associated with increased risk of postoperative complications and other related adverse outcomes.

PURPOSE

The purpose of this study was to (1) assess the incidence of postoperative complications attributable to VI during ALSS, and (2) outcomes secondary to VI such as procedural blood loss, transfusion of blood products, length of stay (LOS), and in hospital mortality.

STUDY DESIGN

Retrospective propensity-score matched, case-control study at 2 academic and 3 community medical centers, PATIENT SAMPLE: Patients 18 years of age or older, undergoing ALSS between January 1st, 2000 and July 31st, 2019 were included in this analysis.

OUTCOME MEASURES

The primary outcome was the incidence of postoperative complications attributable to VI, such as venous thromboembolism, compartment syndrome, transfusion reaction, limb ischemia, and reoperations. The secondary outcomes included estimated operative blood loss (milliliter), transfused blood products, LOS (days), and in-hospital mortality.

METHODS

In total, 1,035 patients were identified, of which 75 (7.2%) had a VI. For comparative analyses, the 75 VI patients were paired with 75 comparable non-VI patients by propensity-score matching. The adequacy of the matching was assessed by testing the standardized mean differences (SMD) between VI and non-VI group (>0.25 SMD).

RESULTS

Two patients (2.7%) had VI-related postoperative complications in the studied period, which consisted of two deep venous thromboembolisms (DVTs) occurring on day 3 and 7 postoperatively. Both DVTs were located in the distal left common iliac vein (CIV). The VI these patients suffered were to the distal inferior vena cava and the left CIV, respectively. Both patients did not develop additional complications in consequence of their DVTs, however, did require systemic anticoagulation and placement of an inferior vena cava filter. There was no statistical difference with the non-VI group where no instances (0%) of postoperative complications were reported (p=.157). No differences were found in LOS or in hospital mortality between the two groups (p=.157 and p=.999, respectively). Intraoperative blood loss and blood transfusion were both found to be higher in the VI group in comparison to the non-VI group (650 mL, interquartile range [IQR] 300-1400 vs. 150 mL, IQR 50-425, p≤.001; 0 units, IQR 0-3 vs. 0 units, IQR 0-1, p=.012, respectively).

CONCLUSION

This study found a low number of serious postoperative complications related to VI in ALSS. In addition, these complications were not significantly different between the VI and matched non-VI ALSS cohort. Although not significant, the found DVT incidence of 2.7% after VI in ALSS warrants vigilance and preventive measures during the postoperative course of these patients.

Sonographic Assessment of Human Lumbar Intervertebral Disks: A Cadaveric Study

Objectives:

The intervertebral disk has traditionally been imaged by magnetic resonance imaging (MRI); however, advances in sonography mean it can now be visualized with this modality. The objectives of this human cadaveric study were to visualize the internal structure of the lumbar intervertebral disks and map any defects. Shear wave sonography was explored as a method for assessing the disks.

Materials and Methods:

In a human cadaver, L4-L5 and L5-S1 disks were imaged with sonography through the anterior abdominal wall and directly through the anterior longitudinal ligament. Gray-scale images and shear wave elastography velocities were obtained. An MRI was performed for image comparison.

Results:

Defects in the disks were clearly seen with sonography, imaging through the anterior abdominal wall and also directly through the anterior longitudinal ligament. The defects identified on sonography were less well visualized on MRI. Shear wave velocities could only be obtained from the anterior aspect of the disk and were unreliable, primarily owing to the stiffness of the tissues.

Conclusion:

Sonography can provide an accurate map of defects within the disk, corresponding with MRI. Shear wave elastography should be used with caution in the human cadaveric intervertebral disk, acknowledging the many confounding factors influencing the measurements.

Post-operative radiculitis following one or two level anterior lumbar surgery with or without posterior instrumentation

The purpose of this study was to define risk factors for non-compression radiculitis following anterior lumbar surgery with or without posterior instrumentation and to define a time to resolution. In this study, we followed 58 consecutive patients who had anterior lumbar surgery with or without posterior instrumentation. We identified those with and without post-operative radiculitis. There as a 36.5% rate of postoperative radiculitis. We found that there was a moderate to strong correlation with height change and radiculitis (p = 0.044). Additionally patients treated with rh-BMP2 had a higher risk of developing symptoms. In all of the patients who developed postoperative radiculitis, symptoms resolved by 3 months. In conclusion 36.5% of patients developed post operative radiculitis. This was associated with the use of rh-BMP2, as well as increasing disc height through surgery. All symptoms resolved by 3 months posoperatively.

Varicocele complicating an anterior lumbar interbody fusion: a case report

Anterior lumbar interbody fusion (ALIF) is performed for the surgical management of lumbar degenerative disc disease with excellent results, particularly for discogenic low back pain. Commonly reported complications associated with this approach include vessel injury, retrograde ejaculation, and ureteral and viscus organ injury. The development of a varicocele after ALIF has not been previously described in the literature. We report a case of varicocele in a 35-year-old patient who underwent ALIF via a left retroperitoneal approach. No intraoperative complications were identified. The postoperative course was uneventful. He was discharged from the hospital on the 5th postoperative day. Three months after surgery, he complained of discomfort and scrotal pain. Examination revealed a grade 3 varicocele according to the Dubin and Amelar classification. Scrotal Doppler US demonstrated dilatation of the veins of the pampiniform plexus. A lumbar CT scan revealed a bulky left spermatic vein closed to the ureter. The patient was treated with platelet anti-aggregation. He was seen at control intervals of 1, 3 and 5 months. Progress was seen as we had a regression of clinical signs. Varicocele appears as an uncommon complication of ALIF. After reviewing the literature, we describe the occurrence of a varicocele following ALIF, its pathophysiology, and its treatment options.

Comparison of Different Approaches in Lumbosacral Spinal Fusion Surgery: A Systematic Review and Meta-Analysis

We aimed to systematically review the literature to analyze the differences in posterior lumbar interbody fusion (PLIF), anterior lumbar interbody fusion (ALIF), and transforaminal lumbar interbody fusion (TLIF), focusing on the complications, risk factors, and fusion rate of each approach. Spinal fusion surgery is a well-established surgical procedure for a variety of indications, and different approaches developed. The various approaches and their advantages, as well as approach-related pathology and complications, are well investigated in spinal surgery. Focusing only on lumbosacral fusion, the comparative studies of different approaches remain fewer in numbers. We systematically reviewed the literature on the complications associated with lumbosacral interbody fusion. Only the PLIF, ALIF, or TLIF approaches and studies published within the last decade (2007–2017) were included. The exclusion criteria in this study were oblique lumbar interbody fusion, extreme lateral interbody fusion, more than one procedure per patient, and reported patient numbers less than 10. The outcome variables were indications, fusion rates, operation time, perioperative complications, and clinical outcome by means of Visual Analog Scale, Oswestry Disability Index, and Japanese Orthopaedic Association score. Five prospective, 17 retrospective, and two comparative studies that investigated the lumbosacral region were included. Mean fusion rates were 91,4%. ALIF showed a higher operation time, while PLIF resulted in greater blood loss. In all approaches, significant improvements in the clinical outcome were achieved, with ALIF showing slightly better results. Regarding complications, the ALIF technique showed the highest complication rates. Lumbosacral fusion surgery is a treatment to provide good results either through an approach for various indications as causes of lower back pain. For each surgical approach, advantages can be depicted. However, perioperative complications and risk factors are numerous and vary with ALIF, PLIF, and TLIF procedures, as well as with fusion rates.

Risk Factors Associated With Femoral Ring Allograft Breakage in ALIF

STUDY DESIGN

This is a retrospective chart review.

OBJECTIVES

To identify the incidence of, and variables correlated with, femoral ring allograft (FRA) fracture following anterior lumbar interbody fusion (ALIF).

METHODS

All patients who underwent ALIF using FRAs at an academic institution over 10 years were included. Postoperative radiographs were reviewed by both the primary and senior authors; fracture and no-fracture groups were created for comparison. Patient and surgical characteristics were extracted from electronic medical records. Frequency data comparisons were performed using contingency table analysis; comparisons of means were analyzed for continuous variables. A multivariate linear regression model was developed using screw use, graft height <12 mm, index level, and weight as variables.

RESULTS

A total of 76 FRAs in 59 patients were identified, 13 (17%) of which fractured. Age, sex, smoking status, use of buttress screws, weight, index level, and presence of spondylolisthesis were not correlated with incidence of fracture (P > .05). There was a significant correlation between the height of FRA and incidence of fracture; 2% (1/52) of grafts ≥12 mm and 50% (12/24) of grafts <12 mm fractured (P < .0001). Using ordinary least-squares regression, this result was independent of patient weight, use of screws, and index level. Of 10 patients, 9 did not require revision surgery to achieve fusion.

CONCLUSIONS

Graft height was the only variable correlated with incidence of FRA fracture. Graft height <12 mm is an independent risk factor for FRA fracture in patients undergoing ALIF, and their use should be avoided in ALIF procedures.

Technique for Exposing Lumbar Discs in Anterior Approach Using Steinmann Wires: Arthroplasties or Arthrodesis

BACKGROUND

Due to increasing longevity, the incidence of degenerative lumbar disc diseases has increased, and surgical treatment is often necessary. In this context, the anterior approach becomes an important technique. However, one of the main limitations of this method is the need for dedicated retractors, which requires larger incisions for its positioning and increases the cost of the procedure. The objective of the present study was to describe a technique for retracting abdominal structures by anterior approaches to the lumbar spine using Steinmann wires.

METHODS

This manuscript consists of a technique description of anterior approach for lumbar spine.

RESULTS

Surgical treatment of degenerative lumbar spine disease is often necessary when the patients have symptoms refractory to conservative treatments. Many of them will be candidates for surgical treatment with anterior approach, either for arthrodesis/anterior lumbar interbody fusion or arthroplasty. Small incisions are performed for positioning the modified Langenbeck retractors and the Steinmann wires. These retractors are easily positioned and provide good exposure of the lumbar discs making it possible to implant appropriate cages for restoring the necessary height, lordosis, and sagittal balance.

CONCLUSIONS

The technique described is safe, inexpensive, and reproducible. Simple and easily accessible instruments are required in most hospital complexes.

Implications of sagittal alignment and complication profile with stand-alone anterior lumbar interbody fusion versus anterior posterior lumbar fusion

Background

Anterior lumbar interbody fusion (ALIF) is commonly utilized in lumbar degenerative pathologies. Standalone ALIF (ST-ALIF) systems were developed to avoid added morbidity, surgical time, and cost of anterior and posterior fusion (APF). Controversy exists in the literature about which of these two techniques yields superior clinical and radiographic outcomes, and few studies have directly compared them. This study seeks to compare ST-ALIF and APF in terms of sagittal correction and surgical complications.

Methods

Ninty-two consecutive ALIF cases performed from 2013-2018 were retrospectively reviewed and separated into 2 groups. Radiographic measurements were performed on pre- and post-operative radiographs, including segmental lordosis (SL), lumbar lordosis (LL), and pelvic incidence-lumbar lordosis mismatch (PI-LL). Surgical complications were determined. Statistical analysis was performed using chi-square test of homogeneity, Fisher's exact test, and independent sample t-test. Comparisons between groups were deemed statistically significant at the P<0.05 threshold.

Results

Fifty-seven ST-ALIF, 35 APF were identified. There were no differences in age, gender, BMI, Charlson Comorbidity Index (CCI), preoperative diagnosis, or surgical level between the 2 cohorts. Bone Morphogenetic Protein (BMP) was utilized in 24.6% of ST-ALIF versus none of APF (P=0.001). No differences were detected in SL, LL, and PI-LL mismatch. ST-ALIF cohort had significantly greater risk of subsidence and revision surgery versus APF (12.3% vs. 0%, RD 95% CI: 3.8-20.8%, P=0.042). Recurrent spondylolisthesis occurred in 5 ST-ALIF cases, 3 cases with implant failure, and 2 nonunions versus none in the APF group.

Conclusions

ST-ALIF was associated with significantly greater subsidence and revision surgery versus APF. Careful patient selection is paramount when considering ST-ALIF. The potential for revision surgery may offset the potential benefit in avoiding posterior fusion. Despite the greater risk of subsidence, sagittal alignment was not significantly affected.

Safety Profile and Radiographic and Clinical Outcomes of Stand-Alone 2-Level Anterior Lumbar Interbody Fusion: A Case Series of 41 Consecutive Patients

Objective: The use of stand-alone 2-level anterior lumbar interbody fusion (ALIF) for degenerative lumbar disease has been increasing as an alternative to routinely augmenting these constructs with posterior fixation or fusion. Despite the potential benefits of a stand-alone approach (decreased cost and operative time, decreased pain and early mobilization), there is a paucity of information regarding these operations in the literature. This investigation aimed to determine the safety profile, radiographic outcomes including fusion rates, improvement in preoperative pain, and spinopelvic parameter modification, for patients undergoing stand-alone 2-level ALIF.

Methods: This retrospective case series involved a chart review of all patients undergoing 2-level stand-alone ALIF at a single tertiary hospital from 2008 to 2018. Data included patient demographics, hospitalization, complications and radiological studies. Visual analog scale (VAS) back and leg scores were measured via patient-administered surveys preoperatively and up to 18 weeks postoperatively.

Results: Forty-one patients who underwent L4-S1 stand-alone ALIF were included. Sixteen (39%) of patients had undergone previous posterior lumbar surgery. Length of stay averaged 4.2 days. Complication rates were comparable to 1-level ALIF. Two patients required reoperation. Fusion rates were 100% for L4-5 and 94.4% for L5-S1. There was no significant change in lumbar lordosis (LL) or LL-pelvic incidence (PI), but there was improved segmental lordosis (SL) and disc height at L4-S1 on final follow-up imaging. There was also modest but statistically significant improvement in VAS back and leg scores.

Conclusions: Stand-alone 2-level ALIF is an option for a surgeon to perform in the absence of significant instability, even in the setting of prior posterior surgery. These procedures increase SL and disc height, but do not have the same effect on LL or LL-PI.

Predictors of inpatient admission in the setting of anterior lumbar interbody fusion: a Minimally Invasive Spine Study Group (MISSG) investigation

OBJECTIVE

While the anterior lumbar interbody fusion (ALIF) procedure may be amenable to ambulatory surgery, it has been hypothesized that limitations such as the risk of postoperative ileus and vascular complications have hindered transition of this procedure to the outpatient setting. Identification of independent risk factors predisposing patients to inpatient stays of ≥ 24 hours after ALIF may facilitate better postsurgical outcomes, target modifiable risk factors, and assist in the development of screening tools to transition appropriate patients to the ambulatory surgery center (ASC) setting for this procedure. The purpose of this study was to identify the most relevant risk factors that predispose patients to ≥ 24-hour admission following ALIF.

METHODS

A prospectively maintained surgical registry was reviewed for patients undergoing single ALIF between May 2006 and December 2019. Demographics, preoperative diagnosis, perioperative variables, and postoperative complications were evaluated according to their relative risk (RR) elevation for an inpatient stay of ≥ 24 hours. A Poisson regression model was used to evaluate predictors of inpatient stays of ≥ 24 hours. Risk factors for inpatient admission of ≥ 24 hours were identified with a stepwise backward regression model.

RESULTS

A total of 111 patients underwent single-level ALIF (50.9% female and 52.6% male, ≤ 50 years old). Eleven (9.5%) patients were discharged in < 24 hours and 116 remained admitted for ≥ 24 hours. The average inpatient stay was > 2 days (53.7 hours). The most common postoperative complications were fever (body temperature ≥ 100.4°F; n = 4, 3.5%) and blood transfusions (n = 4, 3.5%). Bivariate analysis revealed a preoperative diagnosis of retrolisthesis or lateral listhesis to elevate the RR for an inpatient stay of ≥ 24 hours (RR 1.11, p = 0.001, both diagnoses). Stepwise multivariate analysis demonstrated significant predictors for inpatient stays of ≥ 24 hours to be an operation on L4-5, coexisting degenerative disc disease (DDD) with foraminal stenosis, and herniated nucleus pulposus (RR 1.11, 95% CI 1.03-1.20, p = 0.009, all covariates).

CONCLUSIONS

This study provides data regarding the incidence of demographic and perioperative characteristics and postoperative complications as they pertain to patients undergoing single-level ALIF. This preliminary investigation identified the most relevant risk factors to be considered before appropriately transitioning ALIF procedures to the ASC. Further studies of preoperative characteristics are needed to elucidate ideal ASC ALIF patients.

Risk Factors for Postoperative Urinary Tract Infections Following Anterior Lumbar Interbody Fusion

BACKGROUND

Although risk factors contributing to UTI have been studied in posterior approaches to lumbar fusion, there is a lack of literature on factors contributing to UTI in anterior lumbar interbody fusion (ALIF). Our purpose was to identify preoperative independent risk factors for postoperative urinary tract infection (UTI) following anterior lumbar interbody fusion (ALIF) so that surgeons may be able to initiate preventative measures and minimize the risk of UTI-related morbidity following ALIF.

METHODS

The American College of Surgeons-National Surgical Quality Improvement Program database was queried to identify 10 232 patients who had undergone ALIF from 2005 to 2016; 144 patients (1.41%) developed a postoperative UTI while 10 088 patients (98.59%) did not. Univariate analyses were conducted to compare the 2 cohorts' demographics and preoperative comorbidities. Multivariate logistic regression models were then utilized to identify significant predictors of postoperative UTI following ALIF while controlling for differences seen in univariate analyses.

RESULTS

Age ≥ 60 years (P = .022), female sex (P < .001), alcohol use (P = .014), open wound or wound infections (P = .019), and steroid use (P = .046) were independent risk factors for postoperative UTI. Longer operative times were also independent predictors for developing UTI: 120 minutes ≤ x < 180 minutes (P = .050), 180 minutes ≤ x < 240 minutes (P = .025), and ≥ 240 minutes (P = .001). Postoperative UTI independently increased the risk for pneumonia, blood transfusions, sepsis, thromboembolic events, and extended length of stay as well.

CONCLUSIONS

Age ≥ 60 years, female sex, alcohol use, steroid use, and open wound or wound infections independently increased the risk for UTI following ALIF. Future work analyzing the efficacy of tapering alcohol and steroid use preoperatively and reducing procedural time with the aim of lowering UTI risk is warranted. Preoperative wound care is strongly encouraged to decrease UTI risk.

LEVEL OF EVIDENCE

III.

Functional and radiological outcome of anterior retroperitoneal versus posterior transforaminal interbody fusion in the management of single-level lumbar degenerative disease

OBJECTIVE

In this study the authors compared the anterior lumbar interbody fusion (ALIF) and posterior transforaminal lumbar interbody fusion (TLIF) techniques in a homogeneous group of patients affected by single-level L5–S1 degenerative disc disease (DDD) and postdiscectomy syndrome (PDS). The purpose of the study was to analyze perioperative, functional, and radiological data between the two techniques.

METHODS

A retrospective analysis of patient data was performed between 2015 and 2018. Patients were clustered into two homogeneous groups (group 1 = ALIF, group 2 = TLIF) according to surgical procedure. A statistical analysis of clinical perioperative and radiological findings was performed to compare the two groups. A senior musculoskeletal radiologist retrospectively revised all radiological images.

RESULTS

Seventy-two patients were comparable in terms of demographic features and surgical diagnosis and included in the study, involving 32 (44.4%) male and 40 (55.6%) female patients with an average age of 47.7 years. The mean follow-up duration was 49.7 months. Thirty-six patients (50%) were clustered in group 1, including 31 (86%) with DDD and 5 (14%) with PDS. Thirty-six patients (50%) were clustered in group 2, including 28 (78%) with DDD and 8 (22%) with PDS. A significant reduction in surgical time (107.4 vs 181.1 minutes) and blood loss (188.9 vs 387.1 ml) in group 1 (p < 0.0001) was observed. No significant differences in complications and reoperation rates between the two groups (p = 0.561) was observed. A significant improvement in functional outcome was observed in both groups (p < 0.001), but no significant difference between the two groups was found at the last follow-up. In group 1, a faster median time of return to work (2.4 vs 3.2 months) was recorded. A significant improvement in L5–S1 postoperative lordosis restoration was registered in the ALIF group (9.0 vs 5.0, p = 0.023).

CONCLUSIONS

According to these results, interbody fusion is effective in the surgical management of discogenic pain. Even if clinical benefits were achieved earlier in the ALIF group (better scores and faster return to work), both procedures improved functional outcomes at last follow-up. The ALIF group showed significant reduction of blood loss, shorter surgical time, and better segmental lordosis restoration when compared to the TLIF group. No significant differences in postoperative complications were observed between the groups. Based on these results, the ALIF technique enhances radiological outcome improvement in spinopelvic parameters when compared to TLIF in the management of adult patients with L5–S1 DDD.