Development of ethnicity-adjusted global alignment and proportion score to predict the risk of mechanical complications following corrective surgery for adult spinal deformity

BACKGROUND CONTEXT

Surgery for degenerative scoliosis (DS) is a complex procedure with high complication and revision rates. Based on the concept that pelvic incidence (PI) is a constant parameter, the global alignment and proportional (GAP) score was developed from sagittal alignment data collected in the Caucasian populations to predict mechanical complications. However, the PI varies among different ethnic groups, and the GAP score may not apply to Chinese populations. Thus, this study aims to assess the predictability of the GAP score for mechanical complications in the Chinese populations and develop an ethnicity-adjusted GAP score.

PURPOSE

To test the predictability of the original GAP score in the Chinese population and develop a Chinese ethnicity-tailored GAP scoring system.

STUDY DESIGN/SETTINGS

Retrospective cohort study.

PATIENT SAMPLE

A total of 560 asymptomatic healthy volunteers were enrolled to develop Chinese ethnicity-tailored GAP (C-GAP) score and a total of 114 DS patients were enrolled to test the predictability of original GAP score and C-GAP score.

OUTCOME MEASURES

Demographic information, sagittal spinopelvic parameters of healthy volunteers and DS patients were collected. Mechanical complications were recorded at a minimum of 2-year follow-up after corrective surgery for DS patients.

METHODS

A total of 560 asymptomatic healthy volunteers with a mean age of 61.9±14.1 years were enrolled to develop ethnicity-adjusted GAP score. Besides, 114 surgically trated DS patients (M/F=10/104) with a mean age of 60.7±7.1 years were retrospectively reviewed. Demographic data and radiological parameters of both groups, including PI, lumbar lordosis (LL), sacral slope (SS), the sagittal vertical axis (SVA), and global tilt (GT) were collected. Ideal LL, SS, and GT were obtained by calculating their correlation with PI of healthy volunteers using linear regression analysis. Relative pelvic version (RPV), relative lumbar lordosis (RLL), lordosis distribution index (LDI), and relative spinopelvic alignment (RSA) were obtained using the ideal parameters, and the Chinese population adjusted GAP score (C-GAP) was developed based on these values. The predictability of original and C-GAP for mechanical failure was evaluated using clinical and radiological data of DS patients by evaluating the area under the curve (AUC) using receiver operating characteristic curve. This study was supported the National Natural Science Foundation of China (NSFC) (No. 82272545), ($ 8,000-10,000) and the Jiangsu Provincial Key Medical Center, and the China Postdoctoral Science Foundation (2021M701677), Level B ($ 5,000-7,000).

RESULTS

Ideal SS=0.53×PI+9 (p=.002), ideal LL=0.48×PI+22 (p=.023) and ideal GT=0.46 × PI-9 (p=.011). were obtained by correlation analysis using sagittal parameters from those healthy volunteers, and RPV, RLL, RSA, and LDI were calculated accordingly. Then, the ethnicity-adjusted C-GAP score was developed by summing up the numeric value of calculated RPV, RLL, RSA, and LDI. The AUC was classified as ''no or low discriminatory power'' for the original GAP score in predicting mechanical complications (AUC=0.592, p=.078). Similarly, the original GAP score did not correlate with mechanical complications in DS patients. According to the C-GAP score, the sagittal parameters were proportional in 25 (21.9%) cases, moderately disproportional in 68 (59.6%), and severely disproportional in 21% (18.5%) cases. The incidence of mechanical complications was statistically different among proportioned and moderately disproportional and severely disproportional portions of the C-GAP score (p=.03). The predictability of the C-GAP score is high with an AUC=0.773 (p<.001). In addition, there is a linear correlation between mechanical complication rate and C-GAP score (χ=0.102, p=.02).

CONCLUSION

The Ethnicity-adjusted C-GAP score system developed in the current study provided a more accurate and reliable for predicting the risk of mechanical complications after corrective surgery for adult spinal deformity.

Spinal Robotics in Adult Spinal Deformity Surgery: A Systematic Review

Spinal robotics have the potential to improve the consistency of outcomes in adult spinal deformity (ASD) surgery. The objective of this paper is to assess the accuracy of pedicle and S2 alar-iliac (S2AI) screws placed with robotic guidance in ASD patients. PubMed Central, Google Scholar, and an institutional library database were queried until May 2023. Articles were included if they described ASD correction via robotic guidance and pedicle and/or S2AI screw accuracy. Articles were excluded if they described pediatric/adolescent spinal deformity or included outcomes for both ASD and non-ASD patients without separating the data. Methodological quality was assessed using the Newcastle-Ottawa scale. Primary endpoints were pedicle screw accuracy based on the Gertzbein-Robbins Scale and self-reported accuracy percentages for S2AI screws. Data were extracted for patient demographics, operative details, and perioperative outcomes and assessed using descriptive statistics. Five studies comprising 138 patients were included (mean age 66.0 years; 85 females). A total of 1,508 screws were inserted using robotic assistance (51 S2AI screws). Two studies assessing pedicle screws reported clinically acceptable trajectory rates of 98.7% and 96.0%, respectively. Another study reported a pedicle screw accuracy rate of 95.5%. Three studies reported 100% accuracy across 51 total S2AI screws. Eight total complications and 4 reoperations were reported. Current evidence supports the application of robotics in ASD surgery as safe and effective for placement of both screw types. However, due to the paucity of data, a comprehensive assessment of its incremental benefit over other techniques cannot be made. Further work using expanded cohorts is merited.

Defining the Post-Operative Progression of Degenerative Scoliosis: An Analysis of Cases without Instrument Failure

OBJECTIVE

The expected post-operative changes in radiographic alignment over time remain poorly defined in patients surgically treated for degenerative scoliosis without instrument failure. Here we aim to describe the optimal natural progression of radiographic degenerative scoliosis at multiple timepoints in patients treated with a transforaminal lumbar interbody fusion (TLIF).

METHODS

We identified an initial retrospective cohort of 114 patients treated with a TLIF for degenerative scoliosis between 2018 and 2022, with 39 patients ultimately meeting the imaging inclusion criteria. Patients who completed a primary or revision procedure with no evidence of instrument failure, proximal junctional kyphosis, or proximal junctional failure at last follow-up were included. Radiographic measurements of spinopelvic alignment were manually extracted from X-Ray scoliosis films.

RESULTS

Thirty-nine patients (mean age 62.6 ± 8.7, mean follow-up 2.9 years), of which 23 underwent a primary TLIF (Primary) and 16 a revision procedure (Revision), were analyzed. Patients in the Primary group experienced a durable improvement in Thoracolumbar Cobb angle (-25° ± 15°), Thoracic Kyphosis (10° ± 13°), and Pelvic Incidence/lumbar lordosis mismatch (PI/LL) (-19° ± 19°) through the first year of follow-up. In the Revision group, at one year follow-up, all measures of spinopelvic alignment except PI/LL mismatch had reverted to pre-operative levels. Thoracolumbar Cobb angle decreased to a significantly greater degree in the Primary group compared to the Revision group.

CONCLUSION

Primary TLIF operations without instrument failure consistently improve radiographic outcomes in three key measures through the first year. For revision procedures, there appears to be modest radiographic benefit at follow-up.

Polymethyl methacrylate augmentation and proximal junctional kyphosis in adult spinal deformity patients

BACKGROUND

Proximal junctional kyphosis (PJK) is a complication following surgery for adult spinal deformity (ASD) possibly ameliorated by polymethyl methacrylate (PMMA) vertebroplasty of the upper instrumented vertebrae (UIV). This study quantifies PJK following surgical correction bridging the thoracolumbar junction ± PMMA vertebroplasty.

METHODS

ASD patients from 2013 to 2020 were retrospectively reviewed and included with immediate postoperative radiographs and at least one follow-up radiograph. PMMA vertebroplasty at the UIV and UIV + 1 was performed at the surgeons' discretion.

RESULTS

Of 102 patients, 56% received PMMA. PMMA patients were older (70 ± 8 vs. 66 ± 10, p = 0.021), more often female (89.3% vs. 68.2%, p = 0.005), and had more osteoporosis (26.8% vs. 9.1%, p = 0.013). 55.4% of PMMA patients developed PJK compared to 38.6% of controls (p = 0.097), and the rate of PJK development was not different between groups in univariate survival models. There was no difference in PJF (p > 0.084). Reoperation rates were 7.1% in PMMA versus 11.4% in controls (p = 0.501). In multivariable models, PJK development was not associated with the use of PMMA vertebroplasty (HR 0.77, 95% CI 0.38-1.60, p = 0.470), either when considered overall in the cohort or specifically in those with poor bone quality. PJK was significantly predicted by poor bone quality irrespective of PMMA use (HR 3.81, p < 0.001).

CONCLUSIONS

In thoracolumbar fusions for adult spinal deformity, PMMA vertebroplasty was not associated with reduced PJK development, which was most highly associated with poor bone quality. Preoperative screening and management for osteoporosis is critical in achieving an optimal outcome for these complex operations.

LEVEL OF EVIDENCE

4, retrospective non-randomized case review.

Osteoporosis and Vertebral Column

Background

Osteoporosis is an age-related metabolic disease which has a significant impact on bone health and overall quality of life. It is gaining importance as a major medical consideration with the rapid increase in geriatric population globally. It increases the risk of vertebral fractures, progressive spinal deformities and neurological complications, contributing significantly to morbidity and mortality. Increase in life expectancy and advancement of medical technology has led to an increase in the proportion of geriatric patients undergoing orthopaedic procedures. It is becoming vital to adequately evaluate, investigate and treat osteoporosis before planning spinal surgery, especially spinal fusions and instrumentation.

Content

Historically, osteoporosis was considered a contraindication to spine surgery adding to the burden of Disability Adjusted Life Years (DALYs) and mortality. Conversely, osteoporotic patients who underwent spine surgery were not adequately optimized, leading to an increase in failure and complication rates. Better understanding of the pathophysiology of osteoporosis and the biomechanics of an osteoporotic spine with knowledge of current standards of treatment of osteoporosis facilitate the timely and adequate management of this disease. Advances in surgical and anaesthetic techniques facilitate successful surgeries on high-risk elderly and osteoporotic patients with multiple comorbidities allowing for a significantly high predictability for long-term positive outcomes.This article discusses the biomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal disease, and the new treatments, recommendations, surgical indications, strategies and advances in instrumentation in patients with osteoporosis who require spinal surgery.

Implications

In this article, the authors aim to provide a generalized overview for better understanding of the pathophysiological processes underlying osteoporosis in the vertebral column. This review provides a comprehensive set of guidelines for overall health and management of spine patients with pathologies, either caused by or compounded with osteoporosis. An overview of current techniques, strategies and technologies designed to address the challenges associated with spine surgery in osteoporotic patients is also outlined.

Sources

Content for this article has been sourced from routinely cited articles available via PubMed, from National Institute of Health consensus development conference, from the recommendations by World Health Organization technical report series, from previous articles by the authors and from the protocols established by the authors in their clinical practice based on experience and detailed case reviews.

Outcomes of Ponte osteotomy combined with posterior lumbar interbody fusion for reconstruction of coronal and sagittal balance in degenerative scoliosis

PURPOSE

The purpose of the study was to evaluate the clinical efficacy and safety of using Ponte osteotomy combined with posterior lumbar interbody fusion in the treatment of patients with degenerative scoliosis.

METHOD

The medical records and imaging data of degenerative scoliosis patients in our department from 2013 to 2022 were retrospectively collected. A total of 47 patients were included, including 16 male patients and 31 female patients. The mean follow-up was 47.8 months. Whole spine X-rays in the standing position were performed on all patients preoperatively, postoperatively, and at the latest follow-up. The length of hospital stay, complications, operative duration, estimated blood loss, instrumented segment, fused segment, clinical scores, and various radiological indicators were recorded.

RESULTS

The coronal vertical axis improved from 3.1 ± 1.9 cm preoperatively to 1.2 ± 1.0 cm postoperatively with an average reduction of 1.9 ± 1.7 cm. The preoperative coronal Cobb angle was 18.1 ± 10.6°, the immediate postoperative Cobb angle was 6.6 ± 3.9°, and the Cobb angle at the last follow-up was 5.8 ± 3.7°. The sagittal vertical axis decreased from 5.6 ± 3.7 cm preoperatively to 2.7 ± 1.9 cm immediately after the operation and was well maintained at the last follow-up (3.1 ± 2.5 cm). Lumbar lordosis increased from 22.2 ± 10.2° preoperatively to 40.4 ± 8.3° postoperatively and 36.0 ± 8.8° at the last follow-up. The ODI score, VAS low back pain score, and VAS leg pain score were also improved to varying degrees.

CONCLUSION

Ponte osteotomy combined with posterior lumbar interbody fusion can significantly improve coronal and sagittal plane deformities and postoperative functional scores in patients with adult degenerative scoliosis.

L5-S1 pseudoarthrosis rate with ALIF versus TLIF in Adult Spinal Deformity surgeries: A retrospective analysis of 100 patients

OBJECTIVE

Lumbosacral pseudoarthrosis is a common complication following adult spine deformity (ASD) surgery. This study assessed the reoperation rate for L5-S1 pseudoarthrosis in the ASD population. Compared with TLIFs, we hypothesized that ALIF would result in lower rates of L5-S1 pseudarthrosis.

METHODS

This is a single-center study with patient data retrieved from a prospective ASD Database. The patients had a long-segment fusion, ALIF or TLIF at the L5-S1 level with a 2-year follow-up and were divided into two groups (TLIF and ALIF). The study's primary outcome was to assess the difference in the reoperation rate for clinical pseudoarthrosis between the TLIF and the ALIF groups. The secondary outcomes measured the radiological pseudoarthrosis rate and identified risks for L5-S1 pseudoarthrosis development.

RESULTS

100 patients were included; forty-nine patients (mean age 62.9 years,77.5% females) were in TLIF, and 51 patients (mean age 64.4 years,70.6% females) were in the ALIF group. Baseline characteristics were similar in both groups. Thirteen (13%) patients with L5- S1 pseudoarthroses required reoperation. Clinical pseudoarthrosis was higher in the TLIF group than in the ALIF group (12/49 vs 1/51, p<0.001). Univariate analysis demonstrated a higher risk of L5-S1 pseudoarthrosis with TLIF than ALIF (RR 12.4; 95% CI: 1.68-92.4, p<0.001). Multivariate analysis revealed 4.86 times the risk of L5-S1 clinical pseudoarthrosis with TLIF than with ALIF (RR 4.86; 95% CI 0.57-47, P=0.17), but this ratio did not reach statistical significance.

CONCLUSION

No difference in reoperation risk for L5-S1 pseudarthroses was observed based on the method of IF. rhBMP-2 was noted as a significant predictor.

Overloaded axial stress activates the Wnt/β-Catenin pathway in nucleus pulposus cells of adult degenerative scoliosis combined with intervertebral disc degeneration

BACKGROUND

Intervertebral disc degeneration (IVDD) is the initiating factor of adult degenerative scoliosis (ADS), and ADS further accelerates IVDD, creating a vicious cycle. Nevertheless, the role of the Wnt/β-Catenin pathway in ADS combined with IVDD (ADS-IVDD) remains a mystery. Accordingly, this study was proposed to investigate the effect of axial stress on the Wnt/β-Catenin pathway in nucleus pulposus cells (NPCs) isolated from DS-IVDD patients.

METHODS

Normal NPCs (N-NPC) were purchased and the NPCs of young (25-30 years; Y-NPC) and old (65-70 years; O-NPC) from ADS-IVDD patients were primary cultured. After treatment of NPC with overloaded axial pressure, CCK-8 and Annexin V-FITC kits were applied for detecting proliferation and apoptosis of N-NPC, Y-NPC and O-NPC, and western blotting was performed to assess the expression of Wnt 3a, β-Catenin, NPC markers and apoptosis markers (Bax, Bcl2 and Caspase 3).

RESULTS

N-NPC, Y-NPC and O-NPC were mainly oval, polygonal and spindle-shaped with pseudopods, and the cell morphology tended to be flattened with age. N-NPC, Y-NPC and O-NPC were capable of synthesizing proteoglycans and expressing the NPC markers (Collagen II and Aggrecan). Notably, the expression of Wnt 3a, β-Catenin, Collagen II and Aggrecan was reduced in N-NPC, Y-NPC and O-NPC in that order. After overload axial stress treatment, cell viability of N-NPC and Y-NPC was significantly reduced, and the percentage of apoptosis and expression of Wnt 3a and β-Catenin were significantly increased.

CONCLUSIONS

Overloaded axial pressure activates the Wnt/β-Catenin pathway to suppress proliferation and facilitate apoptosis of NPC in ADS-IVDD patients.

Characteristics of pedicle screw misplacement using freehand technique in degenerative scoliosis surgery

PURPOSE

This study aimed to estimate the accuracy of pedicle screw (PS) placement in degenerative scoliosis surgery, characterize a patient population with PS misplacement, and analyze the association between misplaced PS vector and lumbar coronal curve.

METHODS

In this study, 122 patients (average age 68.6 years), who underwent corrective and decompression surgery, were selected retrospectively. PS accuracy was evaluated in the thoracic to lumbar spine. We identified characteristics of misplacement in each patient. Screw positions were categorized into grade A, entirely in the pedicle; grade B, < 2 mm breach; grade C, 2-4 mm breach; and grade D, > 4 mm breach using postoperative computed tomography.

RESULTS

The mean preoperative lumbar coronal curve was 32.3 ± 18.4°, and the number of fused vertebrae was 8.9 ± 2.8. A total of 2032 PS were categorized as follows: grade A, 1897 PS (93.3%); grade B, 67 (3.3%); grade C, 26 (1.3%); and grade D, 43 (2.1%). One PS (grade D), inserted at T5, needed surgery for removal due to neurological deficit. The misplacement group (grades C and D) had a significantly stronger lumbar coronal curve and apical vertebral rotation than the accuracy group (grades A and B). Misplaced PS vector (direction and degree) was significantly correlated with inserted vertebral rotation. Grade D misplacement was distributed mainly around the transitional vertebra of the lumbar curve.

CONCLUSIONS

The accuracy of PS insertion in the thoracic to lumbar spine was high in DS surgery, but the need for care was highlighted in the transitional vertebra.

[Transmuscular approach (XLIF technique) for anterior surgery of the lumbar spine]

OBJECTIVE

Anterior stabilization of the spine with a lateral approach to insert a large and broad cage creating a better bearing surface to restore or maintain the lumbar lordosis.

INDICATIONS

Degenerative scoliosis as well as revision surgery for stenosis of the neuroforamen. Lumbar corpectomies between L2/3 and L4/5 can be approached as well.

CONTRAINDICATIONS

The segment L5/S1 is not suitable for the transmuscular approach. Relative contraindications are previous retroperitoneal surgery and spondylolisthesis with sliding of more than 50% (> Meyerding 2) SURGICAL TECHNIQUE: We describe the transmuscular retroperitoneal approach to the lumbar segments which is called extreme lateral approach (XLIF). To protect the spinal nerves on the way through the psoas muscle, use of intraoperative triggered neuromonitoring is paramount.

POSTOPERATIVE MANAGEMENT

Full mobilization directly after surgery is possible in most cases. Weight bearing should be restricted to 20 kg for 3 months after surgery.

RESULTS

The transmuscular approach to the lumbar spine is a good alternative to reach the anterior part of the lumbar spine. Degenerative scoliosis as well as stenosis of the neuroforamen especially in revision surgery are good indications for this technique. Injuries of the spinal nerves range from 0.7 to 15%. Other complications are rare.

Short-Segment versus Long-Segment Spinal Fusion Constructs for the Treatment of Adult Degenerative Scoliosis: A Comparison of Clinical Outcomes

OBJECTIVE

To compare clinical outcomes of patients diagnosed with degenerative scoliosis undergoing short-segment versus long-segment spinal fusion.

METHODS

A retrospective cohort study was conducted of patients with degenerative thoracolumbar scoliosis undergoing elective spinal fusion at a single academic medical center. Cohorts were divided into short-segment (<3) or long-segment (≥3) groups.

RESULTS

A total of 197 patients (122 short, 75 long) were included. Patients undergoing short-segment fusion more frequently presented with radiculopathy (P < 0.001) and had greater baseline visual analog scale (VAS) leg scores (P < 0.001). Patients with long-segment fusions had longer hospital length of stay (short, 3.82 ± 2.98 vs. long, 7.40 ± 6.85 days; P < 0.001), lower home discharge rates (short, 80.3% vs. long, 51.8; P = 0.003), higher revision surgery rates (short, 10.77% vs. long, 25.3%; P = 0.012), and greater percentage curve correction (short, 37.3% ± 25.9% vs. long, 45.1% ± 23.9%; P = 0.048). No significant differences were noted in postoperative complication rates (short, 1.64% vs. long, 5.33%; P = 0.143). At 1 year, patients with long fusions had worse ΔOswestry Disability Index (ODI) (P = 0.024), ΔVAS leg score (P = 0.002), and VAS leg minimum clinically important difference % (P = 0.003). Multivariate regression found that short-segment fusions were associated with greater improvements in ODI (P = 0.029), Physical Component Summary-12 (P = 0.024), and VAS leg score at 1 year (P = 0.002).

CONCLUSIONS

Patients undergoing short-segment fusions more frequently presented with radiculopathy and had higher preoperative VAS leg scores compared with those receiving long constructs. Short-construct fusions in appropriately selected patients may provide satisfactory improvements in patient-reported outcome measures, particularly ΔODI and ΔVAS leg score, and mitigate hospital length of stay, revision surgery rates, and nonhome discharge.

A comparative study of supine traction, supine side-bending radiographs, and supine MRI to determine coronal flexibility in degenerative lumbar scoliosis patients

PURPOSE

The purpose of this study was to compare curve correction in degenerative lumbar scoliosis using supine traction radiographs, supine side-bending radiographs, and supine MRI.

METHODS

A prospective analysis of Cobb angles from patients diagnosed with degenerative lumbar scoliosis who underwent supine traction radiography (TR), side-bending radiography (SB), and supine MRI. The Cobb angles at thoracic (T), thoracolumbar/lumbar (TL/L), and lumbosacral (LS) levels were measured, and the curve correction in percentages compared with standing AP radiography was calculated as corrective flexibility. Differences in curve correction were analyzed.

RESULTS

In total, 33 patients with an age range of 50-80 years were eligible for inclusion. Traction radiography provided the greatest accuracy in curve correction, with a significant difference from side-bending radiography and supine MRI in T, TL/L, and LS levels (P < 0.001). The difference between side-bending radiography and supine MRI in TL/L and LS levels was not significant (P = 0.721, P = 0.654, respectively). A moderate correlation was found between the corrective flexibility of TR and SB at the T level (0.563, P = 0.001), a strong correlation was observed between the corrective flexibility of TR and SB at the TL/L level (0.709, P < 0.001), and at the TL/L level, a moderate correlation was identified between TR and supine MRI corrective flexibility (0.425, P = 0.014).

CONCLUSIONS

Traction radiographs significantly outperformed side-bending radiographs and supine MRI in terms of access curve flexibility in degenerative lumbar scoliosis.

Relationship between degenerative scoliosis and lower extremity mechanical parameters based on EOS imaging system

OBJECTIVE

This study aimed to assess the correlation between coronal imbalance and lower-limb physiological parameters in degenerative scoliosis using the biplanar whole body imaging system (EOS).

MATERIALS AND METHODS

A total of 101 successive EOS images were selected between January 2018 and December 2021. Of the selected images, 63 patients were in the degenerative scoliosis group (DSG) and 38 patients were in the control group (CG). Two independent observers performed measurements of the parameters and compared the two groups.

RESULTS

Among parameters examined, significant inter-group differences were found for coronal pelvic tilt angle (CPT), bilateral femoral length difference (ΔFL), and bilateral total lower limb length (ΔTL) difference. Additionally, the knee and ankle joints had more severe degeneration on the main curved side in patients with degenerative scoliosis. In the left curved group, 18 (42.86%) and 24 (57.1%) patients had more severe degeneration in the left knee and left ankle, respectively. In the right lateral bending group, 13 (61.9%) and 14 (66.7%) patients had more severe degeneration in the right knee and right ankle, respectively. Statistical differences were found in the degree of degeneration in both knee and ankle joints bilaterally.

CONCLUSION

This study showed that biomechanical parameters of the lower limbs are affected in cases of degenerative scoliosis with altered coronal balance. The lower limb on the main curve side became shorter compared to its counterpart, and joint degeneration of the knee and ankle joints became more severe.

Risk factors for coronal oblique take-off following adult spinal deformity surgery using lateral lumbar interbody fusion and open posterior corrective fusion

PURPOSE

To evaluate risk factors associated with oblique take-off (OT) following lateral lumbar interbody fusion (LLIF) for adult spinal deformity.

METHODS

Thirty-nine consecutive patients (mean age 67.9 years) with scoliosis of the lumbar curve (> 30°) were evaluated. Multilevel LLIF, followed by open thoraco-pelvic posterior corrective fusion after 1 week, was performed. We defined OT as a distance of > 25 mm between the C7 plumb line and the central sacral vertical line and examined risk factors by dividing the patients into the OT and non-OT groups.

RESULTS

OT occurred in 11 patients (28%), all showing a tilt to the convex side. The correction rate of the lumbar curve was approximately 70% range for both groups, which indicated good correction. Preoperative radiographs showed a high L1-central sacral vertical line in the standing position; high L5 tilt in the supine position; high L3, L4, and L5 tilts to the convex side in the supine-bending position; and a high L4 vertebral wedge on the convex side in OT cases. Multiple logistic regression analysis showed that an L4 tilt to the concave side in the bending position was the most effective predictor of OT (odds ratio = 1.104, P = 0.047). For a cutoff value of 16°, the sensitivity and specificity were 73% and 61%, respectively, according to the receiver operating characteristic curve analysis (area under the curve = 0.73).

CONCLUSION

OT occurred in 28% of adult scoliosis patients following LLIF. An L4 tilt > 16° to the concave side in the bending position was the most valuable risk factor.

LEVEL OF EVIDENCE

IV.

Kickstand Rod Technique for Correcting Coronal Imbalance in Adult Scoliosis: 2-Dimensional Operative Video

Restoration of spinal alignment and balance is a major goal of adult scoliosis surgery. In the past, sagittal alignment has been emphasized and was shown to have the greatest impact on functional outcomes. However, recent evidence suggests the impact of coronal imbalance on pain and functional outcomes has likely been underestimated.1,2 In addition, iatrogenic coronal imbalance may be common and frequently results from inadequate correction of the lumbosacral fractional curve.2,3 The "kickstand rod" is a recently described technique to achieve and maintain significant coronal-plane correction.4 Also, of secondary benefit, the kickstand rod may function as an accessory supplemental rod to offload stress and bolster primary instrumentation. This may reduce occurrence of rod fracture (RF) or pseudarthrosis (PA).5  Briefly, this technique involves positioning the kickstand rod on the side of coronal imbalance (along the major curve concavity or fractional curve convexity in our video demonstration). The kickstand rod spans the thoracolumbar junction proximally to the pelvis distally and is secured with an additional iliac screw placed just superior to the primary iliac screw. By using the iliac wing as a base, powerful distraction forces can reduce the major curve to achieve more normal coronal balance. This operative video illustrates the technical nuances of utilizing the kickstand rod technique for correction of severe lumbar scoliosis and coronal malalignment in a 60-yr-old male patient. Alignment correction was achieved and maintained without evidence of RF/PA after nearly 6 mo postoperatively. The patient gave informed consent for surgery and to use imaging for medical publication.

Planned two-stage surgery using lateral lumbar interbody fusion and posterior corrective fusion: a retrospective study of perioperative complications

PURPOSE

To determine the effect of planned two-stage surgery using lateral lumbar interbody fusion (LLIF) on the perioperative complication rate following corrective fusion surgery in patients with kyphoscoliosis.

METHODS

Consecutive patients with degenerative scoliosis who underwent corrective fusion were divided into a control group that underwent single-stage posterior-only surgery and a group that underwent planned two-staged surgery with LLIF and posterior corrective fusion. We collected the patient background and surgical data and assessed the perioperative complication rates. We also investigated spinopelvic parameters and patient-reported outcome measurements (PROMs).

RESULTS

One hundred and thirty-eight patients of mean age 69.8 (range, 50-84) years who met the study inclusion criteria were included. The two-stage group (n = 75) underwent a staged anterior-posterior surgical procedure, and the control group (n = 63) underwent single-stage surgery. There was no significant between-group difference in the incidence of perioperative complications, except for deep wound infection (reoperation is necessary for surgical site infection). Revision surgery within 3 months of the initial surgery was more common in the control group (n = 8, 12.7%) than in the two-stage group (n = 3, 4.0%). Spinopelvic parameters and PROMs were significantly better in the two-stage group at 2 years postoperatively.

CONCLUSION

The complication rate for planned two-stage surgery was similar to that of previous posterior-only single-stage surgery. However, early reoperation was less common, and the degree of spinal correction and clinical results were significantly better after two-stage surgery.

Comparison of degenerative lumbar scoliosis correction and risk for mechanical failure using posterior 2-rod instrumentation versus 4-rod instrumentation and interbody fusion

PURPOSE

Four-rod instrumentation and interbody fusion may reduce mechanical complications in degenerative scoliosis surgery compared to 2-rod instrumentation. The purpose was to compare clinical results, sagittal alignment and mechanical complications with both techniques.

METHODS

Full spine radiographs were analysed in 97 patients instrumented to the pelvis: 58 2-rod constructs (2R) and 39 4-rod constructs (4R). Clinical scores (VAS, ODI, SRS-22, EQ-5D-3L) were assessed preoperatively, at 3 months, 1 year and last follow-up (average 4.2 years). Radiographic measurements were: thoracic kyphosis, lumbar lordosis, spinopelvic parameters, segmental lordosis distribution. The incidence of non-union and PJK were investigated.

RESULTS

All clinical scores improved significantly in both groups between preoperative and last follow-up. In the 2R-group, lumbar lordosis increased to 52.8° postoperatively and decreased to 47.0° at follow-up (p = 0.008). In the 4R-group, lumbar lordosis increased from 46.4 to 52.5° postoperatively and remained at 53.4° at follow-up. There were 8 (13.8%) PJK in the 2R-group versus 6 (15.4%) in the 4R-group, with a mismatch between lumbar apex and theoretic lumbar shape according to pelvic incidence. Non-union requiring revision surgery occurred on average at 26.9 months in 28 patients (48.3%) of the 2R-group. No rod fracture was diagnosed in the 4R-group.

CONCLUSION

Multi-level interbody fusion combined with 4-rod instrumentation decreased risk for non-union and revision surgery compared to select interbody fusion and 2-rod instrumentation. The role of additional rods on load sharing still needs to be determined when multiple cages are used. Despite revision surgery in the 2R group, final clinical outcomes were similar in both groups.

LEVEL OF EVIDENCE

III.

Selection of spinal surgery and hip replacement sequence in patients with both degenerative scoliosis and hip disease

Objective

To discuss how the sequence of spinal surgery and hip replacement is determined for patients with both degenerative scoliosis and hip disease.

Methods

Twenty-six patients treated for both degenerative scoliosis and hip disease from June 2012 to June 2015 were retrospectively studied. Eleven patients underwent hip replacement followed by lumbar surgery (Group A), and 15 patients underwent lumbar surgery followed by hip replacement (Group B). The average follow-up duration was 1.5 years. Related indicators were assessed preoperatively and postoperatively.

Results

The parameters showing significant differences between Groups A and B after surgery were acetabular anteversion, the Oswestry functional disability score, and the Harris hip score. Postoperatively, five patients in Group A had unequal shoulder heights and inclination of the trunk to one side. After lumbar surgery and before total hip arthroplasty in Group B, eight patients could not walk, and the limitation was more severe than that preoperatively.

Conclusion

Spinal surgery may be performed first to resolve lumbar nerve symptoms and restore sagittal balance of the spine; hip replacement may then be performed to simplify hip replacement difficulties and resolve the imbalance after spinal surgery. Severely limited range of motion exists after lumbar surgery and before total hip arthroplasty.

A case report of severe degenerative lumbar scoliosis associated with windswept lower limb deformity

BACKGROUND

The windswept lower limb deformity describes valgus deformity in one leg with varus deformity in the other. It is mostly seen in young children with metabolic bone diseases (such as rickets) and may lead to leg length discrepancy (LLD) and Degenerative scoliosis (DS) in older age. To the best of our knowledge, there was no report of the spinal surgery in patient with severe DS associated with windswept deformity. The objective of this study is to report the unique case of a 60-year-old woman with severe degenerative scoliosis (DS) associated with windswept deformity caused by rickets who underwent a posterior correction and fusion surgery in spine.

CASE PRESENTATION

The patient was diagnosed as rickets windswept lower limb deformity for 50 years but never went through routine treatment. Then, she performed lumbar scoliosis for more than 20 years and suffered from severe back pain for 4 years. After overall clinical evaluation and radiographic measures, we performed a posterior surgical correction and fusion from T9-L5. With this surgery, the main thoracolumbar curve Cobb angle corrected from 72.5° to 21.0°, the coronal balance from 0 cm to 2.0 cm while the sagittal vertical axis (SVA) from 1.5 cm to - 1.0 cm. At 2 years postoperative follow-up, her back pain has almost completely relieved with a satisfied fixation and bone fusion showed on CT scans. However, a coronal imbalance was found with C7-CSVLdistance equal to 4.0 cm. This coronal imbalance was highly correlated to the untreated LLD and pelvic obliquity, and should be improved by standing posture or shoe lifts.

CONCLUSIONS

For such patient, the pure spinal correction and fusion surgery, in spite of lower limbs deformity, can achieve good relieve of back pain symptom, however may accompany by the complication of coronal imbalance due to the unimproved pelvic obliquity and LLD. However, longer follow-up is necessary to observe the long-term outcome of this patient's postoperative coronal imbalance.

Technical Considerations of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion: A Review of Its Early Clinical Results in Application in Adult Degenerative Scoliosis

BACKGROUND

Uniportal endoscopic posterolateral lumbar interbody fusion (Endo-TLIF) provides one of the least invasive forms of minimally invasive surgery, allowing large size cages which are commercially available for open and tubular microscopic transforaminal lumbar interbody fusion (TLIF) to be inserted through this approach. We studied the effect of such a technique on a series of patients with low-grade degenerative scoliosis.

METHODS

Endo-TLIF was applied to patients who had 10°-40° of degenerative adult scoliosis. Pre- and postoperative 1-week, 3-month, and final follow-up clinical status of visual analog scale, Oswestry Disability Index, perioperative complications, and Macnab criteria were collected. Roentgenogram to assess changes in Cobb angles was done.

RESULTS

There was statistically significant improvement of preoperative, 1-week postoperative, 3-month postoperative, and final follow-up mean of visual analog scale scores with 7.72 (5-10), 3.68 (3-6), 2.88 (2-4), and 1.96 (1-3), respectively, and with Oswestry Disability Index mean of 70.4 (52-86), 35.12 (26-56), 27.68 (24-38), and 24 (20-28), respectively (P < 0.05). In terms of Macnab criteria, 100% had good to excellent result. In terms of scoliosis measured by Cobb angle, there was statistically significant improvement.

CONCLUSIONS

Endo-TLIF is a safe and effective procedure in mild to moderate degenerative scoliosis with good early clinical results and improvement in coronal Cobb angle. It can be considered as an option if a short segment(s) fusion is planned for adult degenerative scoliosis.

Risk prediction of degenerative scoliosis combined with lumbar spinal stenosis in patients with rheumatoid arthritis: a case-control study

The purpose of this study is to compare incidence of degenerative scoliosis (DS) in patients who diagnosed lumbar spinal stenosis (LSS) with or without rheumatoid arthritis (RA) and identify the risk factors of DS severity in RA patients. 61 LSS patients with RA (RA group) and 87 demographic-matched LSS patients without RA (NoRA group) from January 2013 to April 2018 were enrolled. The extracted information includes RA-related parameters such as Steinbrocker classification, disease-modifying anti-rheumatic drugs (DMARDs), and DS-related information such as Cobb angle, apical vertebra, along with osteoporosis and history of total knee arthroplasty (TKA). Comparisons between RA and NoRA group and between DS and non-DS subgroup with RA were performed, as well as the risk factors on DS severity in RA patients. The incidence of DS in RA group was 42.6%, larger than that of NoRA group (P = 0.002). The mean Cobb angle between the two groups was of no difference (P = 0.076). The apical vertebrae were both mainly focused on L3 and L4 vertebrae in both groups with no significant difference on the distribution of apical vertebrae (P = 0.786). Female took a larger proportion in DS subgroup than that of NoDS subgroup in patients with RA (P = 0.039), while Steinbrocker classification was irrelevant to the occurrence of DS and Cobb angle. Multiple regression analysis showed that TKA was a risk factor for the severity of Cobb angle (P = 0.040). The incidence of DS in LSS patients with RA is higher than non-RA patients. RA patients performed TKA sustained less severity of DS.

[Comparison of clinical outcomes between type B and type C coronal pattern patients with degenerative scoliosis]

Objective: To investigate the differences of the radiographic and clinical outcomes after posterior correction surgeries between degenerative scoliosis (DS) patients with type B and type C coronal pattern. Methods: From March 2010 to August 2017, the clinical data of 38 patients (type B: 24; type C: 14) who were treated with posterior correction surgeries for DS were retrospectively reviewed. Radiographic parameters including Cobb angle of main curve, coronal imbalance (CI), lumbar lordosis (LL), global kyphosis (GK) and sagittal vertical axis (SVA) were measured on standing anteroposterior and lateral radiographs of the whole spine before and after surgery. Patient-reported outcomes were evaluated by using the visual analogue scale (VAS), the Oswestry disability index (ODI) and SF-36 questionnaire. The independent t-test was applied to compare the difference for statistical analysis. Results: There was no significant differences between the two groups in terms of age, gender, follow-up duration, preoperative curve magnitude, severity of CI, sagittal malalignment and surgical strategies (all P>0.05). In patients with type B coronal pattern, the main curve was corrected from 44°±19° before surgery to 19°±7° immediately after surgery (t=8.496, P<0.001) and to 19°±6° at the last follow-up (t=-0.657, P=0.518). In patients with type C coronal pattern, the main curve was corrected from 43°±9° before surgery to 21°±4° immediately after surgery (t=13.537, P<0.001) and to 21°±5° at the last follow-up (t=-0.186, P=0.856). No significant difference of Cobb angle of main curve was found between the two groups either before the operation or immediately post operation (all P>0.05). In addition, significant improvement of CI was observed after surgery in both groups and the correction was maintained well at the last follow-up. However, patients with type C coronal pattern had greater CI than that in those with type B coronal pattern immediately post operation (t=-2.401, P=0.022) and at the last follow-up (t=-2.659, P=0.012). At the last follow-up the scores of SF-36 questionnaire, ODI and VAS showed significant improvement in both groups (all P<0.05). Conclusion: Posterior correction surgery could provide remarkable radiographic and clinical outcomes in DS patients with type B and type C coronal pattern, and DS patients with type B coronal pattern could achieve a more satisfied coronal balance after surgery.

[Effectiveness of short fusion versus long fusion for degenerative scoliosis with a Cobb angle of 20-40° combined with spinal stenosis]

Objective

To compare the effectiveness of decompression and short fusion or long fusion for degenerative scoliosis (DS) with a Cobb angle of 20-40° combined with spinal stenosis.

Methods

The clinical data of 50 patients with DS who were treated with decompression combined with short fusion or long fusion between January 2015 and May 2017 were retrospectively analysed. Patients were divided into long fusion group (fixed segments>3, 23 cases) and short fusion group (fixed segments≤3, 27 cases). There was no significant difference in gender, age, disease duration, and preoperative visual analogue scale (VAS) score of leg pain, Oswestry disability index (ODI), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), pelvic incidence (PI), pelvic title (PT), and sacral slope (SS) between the two groups ( P>0.05); however, the VAS score of low back pain, Cobb angle, and sagittal vertical axis (SVA) in long fusion group were significantly higher than those in short fusion group ( P<0.05), and the lumbar lordosis (LL) was significantly lower than that in short fusion group ( t=2.427, P=0.019). The operation time, intraoperative blood loss, fluoroscopy times, hospital stay, and complications were recorded and compared. The VAS scores of low back pain and leg pain and ODI score were used to evaluate the clinical outcomes before operation and at last follow-up. X-ray films of the whole spine in standard standing position were taken before operation, at 6 months after operation, and at last follow-up, and the spino-pelvic parameters were measured.

Results

The operation time, intraoperative blood loss, and fluoroscopy times in the short fusion group were significantly less than those in the long fusion group ( P<0.05); there was no significant difference in hospital stay between the two groups ( t=0.933, P=0.355). The patients were followed up 12-46 months with an average of 22.3 months. At last follow-up, the VAS scores of low back pain and leg pain and ODI score significantly improved when compared with those before operation ( P<0.05). Except for the improvement of VAS score of low back pain ( t=8.332, P=0.000), the differences of the improvements of the other scores between the two groups were not significant ( P>0.05). The Cobb angle, SVA, TLK, and PT significantly decreased, while SS and LL significantly increased in the long fusion group ( P<0.05), while the Cobb angle and PT significantly decreased and SS significantly increased in the short fusion group at last follow-up ( P<0.05). There was no significant difference in spino-pelvic parameters between the two groups at 6 months after operation and at last follow-up ( P>0.05). The improvements of Cobb angle, SVA, LL, PT, and SS in the long fusion group were significantly higher than those in the short fusion group at last follow-up ( P<0.05). There was no perioperative death in both groups. The incidence of complications in the long fusion group was 34.8% (8/23), which was significantly higher than that in the short fusion group [11.1% (3/27)] ( χ ²=4.056, P=0.034).

Conclusion

The DS patients with the Cobb angle of 20-40°can achieve satisfactory clinical outcomes and improve the spino-pelvic parameters by choosing appropriate fixation levels. Short fusion has less surgical trauma and fewer complications, whereas long fusion has more advantages in enhancing spino-pelvic parameters and relieving low back pain.

[Efficacy of sequential correction based on satellite rod techniquein degenerative scoliosis with B-type coronal imbalance]

Objective: To evaluate the radiographic and clinical outcomes of sequential correction based on satellite rod technique in degenerative scoliosis (DS) with B-type coronal imbalance, and to investigate the efficacy of sequential correction in this cohort. Methods: Twenty-one DS patients with B-type coronal imbalance applying sequential correction from December 2015 to July 2017 in Nanjing Drum Tower Hospital were retrospectively reviewed. There were 4 males and 17 females in this group, the average age was (63±8) years. The coronal parameters including Cobb angle of main curve and distance between C(7) plumb line and center sacral vertical line (C(7)PL-CSVL), as well as sagittal parameters including global kyphosis (GK) and sagittal vertical axis (SVA) were assessed pre-operatively, post-operatively and at the last follow-up. The Scoliosis Research Society-22 (SRS-22) questionnaire was fulfilled before the operation and at each follow-up to evaluate the quality of life. Paired t test was performed for statistical analysis. Results: The patients were followed-up for (20±8) months. The post-operative Cobb angle of main curve was significantly improved from 52°±12° to 19°±7° (t=13.886, P<0.01), and it was 19°±8° at the last follow-up and no significant correction loss was attained (t=1.101, P=0.284). The values of C(7)PL-CSVL before the operation, after the operation and at the final follow-up were (46±11) mm, (12±7) mm and (12±7) mm, respectively; significant post-operative improvement achieved (t=19.718, P<0.01) while there was no correction loss at last follow-up (t=-1.393, P=0.179). After sequential correction, 20 patients (95.2%) improved to A-type coronal imbalance while 1 patient (4.8%) remained with B-type coronal imbalance. Significant post-operative improvements were found in terms of GK and SVA and no significant correction loss was found during follow-up. The scores of pain and self-image showed significant improvement at the last follow-up (t=8.706, 3.104, both P<0.01). In addition, there was no implant failure during follow-up. Conclusion: The sequential correction based on satellite rod technique in DS patients with B-type coronal imbalance corrects the deformity, relieves the clinical symptoms, improves the quality of life, and decreases the rates of post-operative coronal imbalance as well as implant-related complications.

Minimally Invasive Endoscopic-Assisted Lateral Lumbar Interbody Fusion: Technical Report and Preliminary Results

OBJECTIVE

Lateral lumbar interbody fusion (LLIF) is a highly useful lumbar fusion surgical technique for degenerative spinal disease. However, many complications have already been reported. The purpose of this study is to report the concept, surgical technique, and clinical results of the first 70 consecutive cases treated with a safer and minimally invasive endoscopic-assisted LLIF (ELLIF).

METHODS

This retrospective study included 70 cases involving 106 segments in which ELLIF was used to treat degenerative spinal disease. We examined the clinical progress, complications and analyzed radiographic images. Regarding the fusion rate, 49 cases involving 72 segments whose follow-up period was more than 7 months were evaluated.

RESULTS

The mean of preoperative Numerical Rating Scale (NRS) was 7.0 and postoperative NRS was 1.4. Postoperative NRS had a significant correlation with the number of fusion segments (p = 0.028). The mean of preoperative disc space height, foraminal height, sagittal rotation angle, whole lumbar lordosis and sagittal translation distance were 3.3 mm, 14.3 mm, 2.4°, 9.7°, and 3.2 mm, respectively. Postoperative values were 9.4 mm, 17.9 mm, -4.9°, 36.3°, and 0.7 mm. The fusion rate was 79.2%. Complications included, transient psoas muscle weakness 1, sensory disturbance in the thigh 2, retroperitoneal injury 1, postoperative ileus possibly involving a retroperitoneal injury 1, and cage migration 4.

CONCLUSION

Using the ELLIF in the degenerative spinal disease, we obtained good radiological reduction and good clinical results. Our study confirms that ELLIF is safer and provides better results for degenerative spinal disease. However, the issue of cage migration remains to be resolved.

The cost effectiveness of minimally invasive spine surgery in the treatment of adult degenerative scoliosis: a comparison of transpsoas and open techniques

INTRODUCTION

Surgical treatment improves quality of life in patients with adult degenerative scoliosis (ADS). However, open ADS surgeries are complex, large magnitude operations associated with a high rate of complications. The lateral transpsoas interbody fusion technique is a less invasive alternative to open ADS surgery, but less invasive techniques tend to be more expensive. The objective of this study was to evaluate the cost effectiveness of the transpsoas technique for patients with ADS over a 12-month time horizon from a public payer perspective.

METHODS

A cost-effectiveness analysis was performed based on a consecutive case series of patients who underwent ADS surgeries between 2006 and 2012. Effectiveness was expressed as the difference in patient reported preoperative and 12-month postoperative health-related quality of life (HRQOL), which was measured in quality-adjusted life years. Health-care resource use was tabulated based on a clinical chart review on an item-by-item basis. Unit cost data were obtained from published provincial costs in Alberta, Canada. All costs were adjusted to 2015 Canadian dollars. The base case analysis included costs for the surgery, initial hospitalization, and treatment for complications over a 12-month follow-up period. The uncomplicated case analysis included costs for the surgery and initial hospitalization only. The joint uncertainty surrounding the cost and HRQOL differences was estimated using bootstrapping with 10,000 replicates.

RESULTS

A total of 10 open technique and 12 transpsoas technique T11-pelvis fusions were included in the analysis. In the base case analysis, the transpsoas technique was less costly compared with the open technique, total cost of $83,513 (95% CI: $72,772-$94,253) versus $111,381 (95% CI: $36,340-$186,423), respectively (incremental cost $27,869), and was associated with 0.06 more quality-adjusted life years and/or patient. However, in the uncomplicated case, the open technique was less costly compared with the transpsoas technique ($47,795 [95% CI: $39,003-$56,586] vs $76,510 [95% CI: $72,273-$80,746]), respectively, with an incremental cost of $28,715. Based on the probabilistic analysis of 10,000 bootstrap iterations for the base case analysis, the transpsoas technique was more effective and less costly compared with the open technique 57% of time. One-way deterministic sensitivity analysis by adjusting bone-morphogenetic protein-2 dosage further improved cost effectiveness of the transpsoas technique by lowering overall costs.

CONCLUSIONS

Transpsoas surgeries were associated with better outcomes in terms of HRQOL and lower costs over 1-year follow-up period compared with more invasive open technique. This study should be viewed as a pilot evaluation and should be replicated in a larger prospective multicenter controlled study.

[Surgical results and sagittal alignment analysis of different fusion levels for degenerative scoliosis]

Objective: To retrospectively investigate the effects of long segment fusion and short segment fusion on lumbar sagittal alignment and quality of life in patients with degenerative scoliosis. Methods: From January 2011 to December 2014, 75 patients with degenerative scoliosis were treated with pedicle screw fixation. Total of 56 females and 19 males were included in this study. Fifty-four patients underwent short-segment fusion (≤3 segments) and 21 patients underwent long-segment fusion (>3 segments). The average age of the patients was (63±8) years. The patients were followed-up for a mean time of (2.9±1.3) years. The postoperative follow-up included Cobb angle, pelvic tilt, sacral slope, lumbar lordosis, visual analogue scale of pain on lumbar and lower extremities and Oswestry disability index. Fusion levels, blood loss, surgery length and postoperative hospital stay were recorded. All above parameters were evaluated statistically with Student's t test. Results: The short segment fusion group averaged (1.8±0.7) segments, and the long segment fusion group averaged (5.2±1.6) segments. Coronal Cobb angle changed from (21.3±7.8) degrees preoperatively to (15.3±5.6) degrees at final follow-up in short-segment fusion group (t=2.315, P=0.024) and from (44.5±11.2) degrees preoperatively to (11.4±5.8) degrees at the final follow-up in long-segment fusion group (t=8.214, P<0.01). In the short segment fixation group, the preoperative lumbar lordosis changed from (44.3±9.7) degrees to (48.9±8.2) degrees at final follow-up (t=2.123, P=0.038), and it changed from (25.3±9.5) degrees to (52.1±11.2) degrees in the long segment fusion group (t=5.982, P<0.01). The sacral slope in the short segment fusion group increased from (22.6±6.8) degrees preoperatively to (34.1±7.5) degrees at the final follow-up (t=2.872, P=0.006), and it increased from (12.1±9.5) degrees to (37.8±8.4) degrees in long segment fusion group (t=7.314, P<0.01). The pelvic tilt in the short segment fusion group changed from (23.5±5.5) degrees preoperatively to (19.5±4.7) degrees at final follow-up (t=2.217, P=0.031), and it decreased from (27.1±6.1) degrees to (22.9±4.3) degrees in the long segment fusion group(t=2.131, P=0.045). The visual analogue scale of pain on lumbar and lower extremities and Oswestry disability index were all improved after the operation in both groups. Conclusions: Both short segment fusion and long segment fusion can achieve satisfactory surgical results and improves the spinal-pelvic parameters. Short segment fusion can reduce surgery trauma and shorten hospital stay relative to long segment fixation.

Sagittal spinopelvic malalignment in degenerative scoliosis patients: isolated correction of symptomatic levels and clinical decision-making

Background

This study aims to determine if (1) loss of lumbar lordosis (LL), often associated with degenerative scoliosis (DS), is structural or rather largely due to positional factors secondary to spinal stenosis; (2) only addressing the symptomatic levels with a decompression and posterolateral fusion in carefully selected patients will result in improvement of sagittal malalignment; and (3) degree of sagittal plane correction achieved with such a local fusion could be predicted by routine pre-operative imaging.

Methods

A retrospective study design with prospectively collected imaging data of a consecutive series of surgically treated DS patients who underwent decompression and instrumented fusion at only symptomatic levels was performed. Pre- and post-operative plain radiographs and pre-operative magnetic resonance imaging (MRIs) of the spinopelvic region were analyzed. LL, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were assessed in all patients. As a requirement for the surgical strategy, all patients presented with a pre-operative PI-LL mismatch greater than 10^°. Post-operative complications were assessed.

Results

Pre-operative MRIs and lumbar extension radiographs revealed a mean LL of 42^° (range 10-66^°) and 48^° (range 20-74^°), respectively, in 68 patients (mean follow-up 29 months). LL post-operatively was corrected to a mean PI-LL of 10^°. Of patients who achieved PI-LL mismatch within 10^o on their pre-operative extension lateral lumbar radiographs, 62.5% were able to maintain a PI-LL mismatch within 10^° on their initial post-operative films. Only 37.5% were not able to achieve that mismatch on extension radiographs (p = 0.001, OR = 9.58). Similarly, 54.2% were able to achieve a PI-LL < 10^° on initial post-operative radiographs, when pre-operative MRI revealed a PI-LL mismatch within 10^°. In contrast, only 20.5% achieved that goal post-operatively if their mismatch was greater than 10^o on their MRI (p = 0.003, OR = 4.25).

Conclusion

With a decompression and instrumented fusion of only the symptomatic levels in symptomatic DS patients, we were able to achieve a PI-LL mismatch to within 10^°. The loss of LL observed pre-operatively may be largely positional rather than structural. The amount of LL correction observed immediately after surgery can be predicted from pre-operative lumbar extension radiographs and supine sagittal MRI.

Prevalence and Indications for Unplanned Reoperations Following Index Surgery in the Adult Symptomatic Lumbar Scoliosis NIH-Sponsored Clinical Trial

STUDY DESIGN

Longitudinal cohort.

OBJECTIVE

To report on the prevalence and indications for unplanned reoperations following index surgery in the Adult Symptomatic Lumbar Scoliosis NIH-sponsored Clinical Trial.

SUMMARY OF BACKGROUND DATA

Reoperation following adult spinal deformity surgery exposes the patient to additional surgical risk, increases the cost of care, and decreases the potential cost-effectiveness of the intervention. Accurate data regarding the prevalence and indication for reoperation will facilitate future efforts to minimize risk.

METHODS

A total of 153 patients underwent adult spinal deformity surgery as part of the observational, randomized, or crossover groups and were eligible for two-year follow-up. Reoperations were meticulously tracked as part of the National Institutes of Health (NIH)-mandated serious adverse event (SAE) reporting. The primary indication for reoperation was obtained from the treating surgeon's operative report.

RESULTS

Thirty-two patients had one reoperation, two patients underwent two reoperations, and three patients underwent three reoperations. A total of 45 reoperations were performed in 37 patients. Eleven patients (7%) underwent reoperation within 90 days of the index surgery: two for superficial wound dehiscence, three for radiculopathy with screw removal, and six for acute proximal junctional failure (PJF). Four patients underwent reoperation for PJF more than 90 days from index surgery. Twenty-six patients underwent 28 reoperations for rod fracture/pseudoarthrosis.

CONCLUSION

In a consecutive series of adult spinal deformity surgery patients with meticulous follow-up, 24% of patients required an unplanned reoperation. The most common indication for reoperation was rod fracture/pseudoarthrosis, which occurred from 9 months to 3.7 years following the index surgery and accounted for 62% (28/45) of the reoperations. The second most common indication for reoperation was PJF, which occurred from 1 month to 1.6 years following index surgery and accounted for 22% (10/45) of the reoperations. As these complications will likely increase with longer follow-up, efforts to lower the rates of these complications are warranted.

LEVEL OF EVIDENCE

Level II.

Risk factors of perioperative complications for posterior spinal fusion in degenerative scoliosis patients: a retrospective study

Backgrounds

Rare study has been conducted to detect risk factors of perioperative complications, which are closely related to preoperative status of the patients and surgical stress. The aim of this study is to detect these relationships in degenerative scoliosis (DS) patients.

Methods

Perioperative complications of 226 cases with DS (56 males and 170 females; 65.5 ± 8.1 years old), who accepted posterior fusion in our hospital from January, 2013 to July, 2017, were retrospectively reviewed. Potential risk factors were first compared between patients with or without perioperative complications using student t test or Chi-squared test. Then, the unevenly distributed variables between the two groups were analyzed with binary logistic regression model.

Results

All patients separately underwent decompression with short limited instrumentation (116, 51.3%) or with long instrumentation for correction (110, 48.7%). The mean operation duration (OD) was 216.9 ± 64.2 min and the average amount of bleeding was 587.4 ± 357.2 ml. 44 cases (19.5%)suffered from the complications during the perioperative phase, including incision complications (5.3%), urinary infection (3.5%), dura tears/cerebrospinal fluid (CSF) leakages (3.5%) and new neurological deficits (2.7%). Hospital stay was significantly extended for the complications (p < 0.001). Univariate analysis showed that OD (p < 0.001), bleeding (p = 0.014), American Standards Association (ASA) grade > 2 (p = 0.011) and RBC transfusion≥4 U(p = 0.028) were associated with these complications. Multivariate logistic regressions revealed that only ASA grade > 2(p = 0.011, Odds Ratio[OR] = 4.104, 95% Confidence Interval[CI] = 1.413~ 11.917) and OD (p = 0.013, OR = 2.697, 95% CI = 1.233~ 5.899) were the independent risk factors.

Conclusions

The high morbidity of perioperative complications for posterior spinal fusion would significantly extend hospital stay of DS patients. It was independently related to higher ASA grade and longer OD.

Optimal Pelvic Incidence Minus Lumbar Lordosis Mismatch after Long Posterior Instrumentation and Fusion for Adult Degenerative Scoliosis

OBJECTIVE

To evaluate the influence of Scoliosis Research Society (SRS)-Schwab sagittal modifiers of pelvic incidence minus lumbar lordosis mismatch (PI-LL) on clinical outcomes for adult degenerative scoliosis (ADS) after long posterior instrumentation and fusion.

METHODS

This was a single-institute, retrospective study. From 2012 to 2014, 44 patients with ADS who underwent posterior instrumentation and fusion treatment were reviewed. Radiological evaluations were investigated by standing whole spine (posteroanterior and lateral views) X-ray and all radiological measurements, including Cobb's angle, LL, PI, and the grading of vertebral rotation, were performed by two experienced surgeons who were blind to the operations. The patients were divided into three groups based on postoperative PI-LL and the classification of the SRS-Schwab: 0 grade PI-LL (<10°, n = 13); + grade PI-LL (10°-20°, n = 19); and ++ grade PI-LL (>20°, n = 12). The clinical outcomes were assessed according to Japanese Orthopaedic Association (JOA) score, Oswestry Disability Index (ODI), Visual Analog Scale (VAS), Lumbar Stiffness Disability Index (LSDI), and complications. Other characteristic data of patients were also collected, including intraoperative blood loss, operative time, length of hospital stay, complications, number of fusion levels, and number of decompressions.

RESULTS

The mean operative time, blood loss, and hospital stay were 284.5 ± 30.2 min, 1040.5 ± 1207.6 mL, and 14.5 ± 1.9 day. At the last follow-up (2.6 ± 0.6 years), the radiological and functional parameters, except the grading of vertebral rotation, were all significantly improved in comparison with preoperative results (P < 0.05), but it was obvious that an ideal PI-LL (≤10°) was not achieved in some patients. Significant differences were only observed among the three groups in the ODI and LSDI. Patients with + grade PI-LL seemed to have the best surgical outcome compared to those with 0 and ++ grade PI-LL, with the lowest ODI score (+ grade vs 0 grade, 17.3 ± 4.9 vs 26.0 ± 5.4; + grade vs ++ grade, 17.3 ± 4.9 vs 32.4 ± 7.3; P < 0.05) and lower LSDI (+ grade vs 0 grade, 1.6 ± 1.0 vs 3.5 ± 0.5, P < 0.05; + grade vs ++ grade, 1.6 ± 1.0 vs 0.6 ± 0.5, P > 0.05). A Pearson correlation analysis further demonstrated that LSDI was negatively associated with PI-LL. Furthermore, the incidence rate of postoperative complications was lower in patients with + grade PI-LL (1/19, 5.26%) than that in patients with 0 (2/13, 15.4%) and ++ grade PI-LL (3/12, 25%).

CONCLUSION

Our present study suggest that the ideal PI-LL may be between 10° and 20° in ADS patients after long posterior instrumentation and fusion.

Long-term outcomes of transforaminal lumbar interbody fusion in patients with spinal stenosis and degenerative scoliosis

BACKGROUND CONTEXT

Patients with spinal deformity may present with complaints related to either the deformity itself or the manifestations of the coexisting spinal stenosis. There are reports of successful management of lumbar pathology in the absence of global sagittal or coronal imbalance, with limited decompression and fusion, addressing only the symptomatic segment.

PURPOSE

Our study examined the long-term outcomes of transforaminal lumbar interbody fusion (TLIF), a less extensive procedure, based on the experience of the senior author over the past 10 years.

STUDY DESIGN/SETTING

This was a retrospective study of symptomatic lumbar spinal stenosis and spinal deformity managed by one surgeon at The Cleveland Clinic since 2003.

PATIENT SAMPLE

Forty-one patients were included in the study.

OUTCOME MEASURES

The present study measures the long-term clinical functional outcomes of these patients through EQ-5D (EuroQol five dimensions questionnaire), PHQ-9 (Patient Health Questionnaire), and PDQ (Pain Disability Questionnaire) forms, along with documented radiographic parameters and Charlson Comorbidity Index (CCI).

METHODS

There were no funding or potential conflicts of interest associated biases in the present study. Patients with symptomatic lumbar spinal stenosis with neutral global alignment in the sagittal and coronal planes and symptomatic stenosis at the deformity level were treated by limited fusion and TLIF, and had a follow-up period of at least 5 years. Excluded were patients under 18 years of age, had more than three levels of fusion, and had an active spinal malignancy or recent spinal trauma. The grouping variables were curve magnitude, revision surgeries, and TLIF levels. Clinical outcomes were compared in all the grouping variables. Analysis of variance (ANOVA) and chi-square tests were utilized; p<.05 was considered statistically significant.

RESULTS

The average age and follow-up period were 66±10 and 7.5 years, respectively. There was no statistical difference between patients with curves measuring between 10° and 20° and greater than 20° for EQ-5D, PHQ-9, and PDQ. Patients had worse PDQ data with larger curves compared with smaller curves at both 5 years and final follow-up. Although there was no statistical significance between preoperative coronal curve magnitude and revision surgeries, patients with curves greater than 20° had higher rates of revision surgeries (75%; p=.343) in the global lumbar curve deformity group. Although there was no statistical significance for patients who underwent revision surgeries,those patients had low PHQ-9 values at the final follow-up (p=.09). The revision surgery rate was 48% in one-level TLIF and 18% in two-level TLIF. Moderate pain disability scores were noticed for one-level TLIF patients (mean=75) compared with two-level TLIF patients (mean=27) at the final follow-up, and approached statistical significance in this comparison (p=.06).

CONCLUSION

Although this topic has a limited audience to spinal deformity surgeons, the prevalence of patients who present with adult spinal deformities has been increasing. Short segment fusion, in the setting of modest spinal deformity, is a reasonable and safe option. Further study on the concept of short segment fusions in the growing patient population is required as more comprehensive fusions do have noted complication rates, and a compromise must be reached between the extent of surgery that is enough to provide pain relief and disability and the degree of surgery that is too much to be tolerated in terms of complication rates.

Minimally Invasive Spinal Surgery for Adult Spinal Deformity

The purpose of this review is to present the current techniques and outcomes of adult spine deformity (ASD) surgery using the minimally invasive spine surgery (MISS) approach. We performed a systemic search of PubMed for literature published through January 2018 with the following terms: "minimally invasive spine surgery," "adult spinal deformity," and "degenerative scoliosis." Of the 138 items that were found through this search, 57 English-language articles were selected for full-text review. According to the severity of the deformity and the symptoms, various types of MISS have been utilized, such as MISS decompression, circumferential MISS, and hybrid surgery. With proper indications, the MISS approach achieved satisfactory clinical and radiological outcomes for ASD, with reduced complication rates. Future studies should aim to define clear indications for the application of various surgical options.

Osteoporosis and the Management of Spinal Degenerative Disease (II)

Osteoporosis has become a major medical problem as the aged population of the world rapidly grows. Osteoporosis predisposes patients to fracture, progressive spinal deformities, and stenosis, and is subject to be a major concern before performing spine surgery, especially with bone fusions and instrumentation. Osteoporosis has often been considered a contraindication for spinal surgery, while in some instances patients have undergone limited and inadequate procedures in order to avoid concomitant instrumentation. As the population ages and the expectations of older patients increase, the demand for surgical treatment in older patients with osteoporosis and spinal degenerative diseases becomes progressively more important. Nowadays, advances in surgical and anesthetic technology make it possible to operate successfully on elderly patients who no longer accept disabling physical conditions. This article discusses the biomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal conditions, as well as the novel treatments, recommendations, surgical indications, strategies and instrumentation in patients with osteoporosis who need spine operations.

Minimally invasive techniques for lumbar decompressions and fusions

PURPOSE OF REVIEW

The purpose of this study is to summarize the recent literature investigating the use of minimally invasive (MIS) techniques in the treatment of lumbar degenerative stenosis, spondylolisthesis, and scoliosis.

RECENT FINDINGS

MIS lumbar decompression and fusion techniques for degenerative pathology are associated with reduced operative morbidity, shortened length of hospital stay, and reduced postoperative pain and narcotics utilization. Recent studies with long-term clinical follow-up have demonstrated equivalence in clinical outcomes between open and MIS surgical procedures. Radiographically, MIS procedures provide adequate postoperative correction of coronal alignment. Correction of sagittal alignment, however, is more variable based on current reports. MIS techniques are both safe and effective in the treatment of lumbar degenerative pathologies. While some studies have reported on long-term outcomes and costs associated with MIS procedures, more investigation into these topics is still necessary. Additionally, further work is required to analyze the training requirements and learning curves of MIS procedures to better promote adoption amongst surgeons.

Application of Gelatin Sponge Impregnated with a Mixture of 3 Drugs to Intraoperative Nerve Root Block Combined with Robot-Assisted Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery in the Treatment of Adult Degenerative Scoliosis: A Clinical Observation Including 96 Patients

OBJECTIVE

Application of nerve root block is mainly for diagnosis with less application in intraoperative treatment. The aim of this study was to observe clinical and imaging outcomes of application of gelatin sponge impregnated with a mixture of 3 drugs to intraoperative nerve root block combined with robot-assisted minimally invasive transforaminal lumbar interbody fusion surgery in to treat adult degenerative lumbar scoliosis.

METHODS

From January 2012 to November 2014, 108 patients with adult degenerative lumbar scoliosis were treated with robot-assisted minimally invasive transforaminal lumbar interbody fusion surgery combined with intraoperative gelatin sponge impregnated with a mixture of 3 drugs. Visual analog scale and Oswestry Disability Index scores were used to evaluate postoperative improvement of back and leg pain, and clinical effects were assessed according to the 36-Item Short-Form Health Survey. Imaging was obtained preoperatively, 1 week and 3 months postoperatively, and at the last follow-up. Fusion status, complications, and other outcomes were assessed.

RESULTS

Follow-up was complete for 96 patients. Visual analog scale scores of leg and back pain on postoperative days 1-7 were decreased compared with preoperatively. At 1 week postoperatively, 3 months postoperatively, and last follow-up, visual analog scale score, Oswestry Disability Index score, coronal Cobb angle, and coronal and sagittal deviated distance decreased significantly (P = 0.000) and lumbar lordosis angle increased (P = 0.000) compared with preoperatively. Improvement rate of Oswestry Disability Index was 81.8% ± 7.4. Fusion rate between vertebral bodies was 92.7%.

CONCLUSIONS

Application of gelatin sponge impregnated with 3 drugs combined with robot-assisted minimally invasive transforaminal lumbar interbody fusion for treatment of adult degenerative lumbar scoliosis is safe and feasible with advantages of good short-term analgesia effect, minimal invasiveness, short length of stay, and good long-term clinical outcomes.

Osteoporosis and the Management of Spinal Degenerative Disease (I)

Osteoporosis has become a major medical problem as the aged population of the world rapidly grows. Osteoporosis predisposes patients to fracture, progressive spinal deformities, and stenosis, and is subject to be a major concern before performing spine surgery, especially with bone fusions and instrumentation. Osteoporosis has often been considered a contraindication for spinal surgery, while in some instances patients have undergone limited and inadequate procedures in order to avoid concomitant instrumentation. As the population ages and the expectations of older patients increase, the demand for surgical treatment in older patients with osteoporosis and spinal degenerative diseases becomes progressively more important. Nowadays, advances in surgical and anesthetic technology make it possible to operate successfully on elderly patients who no longer accept disabling physical conditions. This article discusses the biomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal conditions, as well as the novel treatments, recommendations, surgical indications, strategies and instrumentation in patients with osteoporosis who need spine operations.

Increase in spinal deformity surgery in patients age 60 and older is not associated with increased complications

BACKGROUND CONTEXT

Surgical treatment for adult spinal deformity improves patient quality of life; however, trends in surgical utilization in the elderly, who may be at higher risk for complications, remain unclear.

PURPOSE

To identify trends in the utilization of adult deformity and determine complication rates among older patients.

STUDY DESIGN

This is a retrospective database analysis.

PATIENT SAMPLE

The Nationwide Inpatient Sample database was queried from 2004 to 2011 to identify adult patients who underwent spinal fusion of eight or more levels using International Classification of Diseases, Ninth Revision (ICD-9) coding.

OUTCOME MEASURES

Incidence of surgery, complication rates, length of stay, and total hospital charges.

METHODS

The incidence of surgery was normalized to United States census data by age group. Trends in complications, length of stay, and inflation-adjusted hospital charges were determined using linear regression and Cochran-Armitage trend testing.

RESULTS

An estimated 29,237 patients underwent adult spinal deformity surgery with an increase from 2,137 to 5,030 cases per year from 2004 to 2011. Surgical incidence among patients 60 years and older increased from 1.9 to 6.5 cases per 100,000 people from 2004 to 2011 (p<.001), whereas utilization in patients younger than 60 increased from 0.59 to 0.93. Linear regression revealed that the largest increase in surgical utilization was for patients aged 65-69 years with an increase of 0.68 patients per 100,000 people per year (p<.001), followed by patients aged 70-74 years with a rate of 0.56 patients per 100,000 people per year (p=.001). Overall complication rates were 22.5% in 2004 and 26.7% in 2011. Although complication risk increased with age (≥60 vs. <60: relative risk 1.91 [1.83, 1.99], p<.001), within-age group rates were stable over time. Mean length of stay was 9.6 days in 2004 and 9.0 days in 2011. Inflation-adjusted mean hospital charges increased from $171,517 in 2004 to $303,479 in 2011 (p<.001).

CONCLUSIONS

Operative management of adult spinal deformity increased 3.4-fold among patients ≥60 years from 2004 to 2011, with an associated 1.8-fold increase in hospital charges. Although the exact reasons for the striking increase in hospital charges remain unclear, some of the increase is likely related to decreasing reimbursement of charges by payors over the same period of time. The large majority of cases were performed in large academic centers, and growth in deformity trained spine specialists in these centers may have contributed to this trend. Despite the increased utilization of surgery for adult spinal deformity, in-hospital complications remained stable across all ages.

Clinical and radiological outcomes after decompression and posterior fusion in patients with degenerative scoliosis

OBJECTIVE

The prevalence of degenerative scoliosis (DS) increases with age and an overall increase is seen due to the aging population. This study aims to evaluate the clinical and radiological outcomes after decompression and posterior fusion in patients with DS.

METHODS

In this is prospective study, 43 patients with DS, aged 37 to 70 years, were eligible to undergo decompression and posterior fusion. Primary outcomes were low back pain (LBP) with or without radicular pain, which was evaluated preoperatively and at 12 and 24 months after surgery with the use of a visual analog scale (VAS), and the quality of life (QOL), which was assessed at the same time periods by the Oswestry Disability Index (ODI) questionnaire. The Cobb's method was used to measure the degree of scoliosis in each patient preoperatively and at 24 hours, 12 and 24 months after the surgery.

RESULTS

VAS scores improved significantly from a mean of 8.18 preoperatively to 4.48 at 12 months and 3.07 at 24 months postoperatively (P < .001). The mean radicular pain scores also decreased significantly (P < .001). At postoperative 12 months, the mean ODI score was significantly lower than the mean preoperative ODI score (47.81 ± 16.06 vs. 72.18 ± 12.28; P = .001). ODI score at 24 months postoperatively was significantly better than the preoperative ODI (15.53 ± 7.21 vs. 72.18 ± 12.28; P = .016). The mean Cobb angle changed significantly from 31.4° ± 4.88 preoperatively to 3.28° ± 2.10 at 24 months postoperatively (P < .001).

CONCLUSIONS

Our findings suggest that decompression and posterior fusion in the patients with DS is an effective surgical method which is associated with satisfying clinical results in terms of improvement of postoperative LBP, radicular pain, and QOL, and correction of Cobb angle at 12 and 24 months after the surgery and restoration of sagittal alignment at 2 months postoperatively.

Correlation between radiographic parameters and functional scores in degenerative lumbar and thoracolumbar scoliosis

INTRODUCTION

Adult scoliosis is a condition in which the spinal deformity occurs because of degeneration. Although various studies have agreed on the importance of restoring the sagittal balance, few have evaluated the relationship between functional scores and radiological parameters. The primary objective of this retrospective study was to demonstrate the correlation between radiographic parameters and functional outcomes in adult patients with lumbar or thoracolumbar degenerative scoliosis. The secondary objective was to assess the long-term effects of posterolateral fusion for treating this deformity.

STUDY OUTLINE

This single-centre retrospective study included 47 patients over 50years of age who had degenerative lumbar scoliosis treated with an instrumented posterolateral fusion; the mean follow-up was 6.4years (range 2 to 20).

METHODS

Radiographic analysis of A/P and lateral full spine standing radiographs was carried out with the KEOPS software. Three pelvic parameters (pelvic tilt, pelvic incidence, sacral slope), two spinal parameters (lumbar lordosis and thoracic kyphosis) and three sagittal balance parameters (C7 sagittal tilt, C7 Barrey's ratio and spinosacral angle) were calculated. The functional outcomes were evaluated through three self-assessment questionnaires: Oswestry Disability Index, SRS-30 and SF-36. The correlation between clinical and radiographic parameters was calculated with Spearman's correlation test.

RESULTS

There was a significant correlation between the SF-36 (PCS) and the following three sagittal parameters: sacral slope (r=-0.31453; P=0.04), lumbar lordosis (r=-0.30198; P=0.0491) and spinosacral angle (r=-0.311967; P=0.0366). The mean ODI score was 33.61, which corresponds to minimal to moderate disability. The mean physical (PCS) and mental (MCS) component summary scores of the SF-36 were 37.70 and 38.40, respectively. The mean SRS-30 score was 3.07.

CONCLUSION

It is essential that the sagittal balance be restored when treating degenerative lumbar scoliosis to generate better functional outcomes and better quality of life. To achieve this correction, instrumented posterolateral fusion appears to be a very reliable technique that leads to lasting improvement.

LEVEL OF EVIDENCE

IV.

Do the disc degeneration and osteophyte contribute to the curve rigidity of degenerative scoliosis?

Background

The factors associated with lateral curve flexibility in degenerative scoliosis have not been well documented. Disc degeneration could result in significant change in stiffness and range of motion in lateral bending films. The osteophytes could be commonly observed in degenerative spine but the relationship between osteophyte formation and curve flexibility remains controversial. The aim of the current study is to clarify if the disc degeneration and osteophyte formation were both associated with curve flexibility of degenerative scoliosis.

Methods

A total of 85 patients were retrospectively analyzed. The inclusion criteria were as follow: age greater than 45 years, diagnosed as degenerative scoliosis and coronal Cobb angle greater than 20°. Curve flexibility was calculated based on Cobb angle, and range of motion (ROM) was based on disc angle evaluation. Regional disc degeneration score (RDS) was obtained according to Pfirrmann classification and osteophyte formation score (OFS) was based on Nanthan classification. Spearman correlation was performed to analyze the relationship between curve flexibility and RDS as well as OFS.

Results

Moderate correlation was found between RDS and curve flexibility with a Spearman coefficient of −0.487 (P = 0.009). Similarly, moderate correlation was observed between curve flexibility and OFS with a Spearman coefficient of −0.429 (P = 0.012). Strong correlation was found between apical ROM and OFS compared to the relationship between curve flexibility and OFS with a Spearman coefficient of −0.627 (P < 0.001).

Conclusions

Both disc degeneration and osteophytes formation correlated with curve rigidity. The pre-operative evaluation of both features may aid in the surgical decision-making in degenerative scoliosis patients.

Suppression of mTOR signaling pathway promotes bone marrow mesenchymal stem cells differentiation into osteoblast in degenerative scoliosis: in vivo and in vitro

To investigate the role of mTOR signaling pathway in bone marrow mesenchymal stem cells (BMSCs) differentiation into osteoblast in degenerative scoliosis (DS). The rat model of DS was established. Thirty-two Sprague-Dawley (SD) rats were selected and divided into the normal control group, the positive control group (normal rats injected with rapamycin), the negative control group (DS rats injected with PBS) and the experiment group (DS rats injected with rapamycin). H&E staining was performed to observe the osteogenesis of scoliosis. The BMSCs were obtained and assigned into seven groups: the normal control group, the positive control group, the negative control group and 1.0/10.0/100.0/1000.0 nmol/L experiment groups. Flow cytometry was conducted to testify cell cycle. The mRNA and protein expressions of mTOR and osteoblastic differentiation markers were measured by qRT-PCR and western blotting. In vivo, compared with the negative control group, bone trabecular area and the number of differentiated bone cells were significantly increased in the experiment groups. In vitro, at 24 and 48 h after rapamycin treatment, compared with the negative control group, BMSCs at G0/G1 stage increased, but BMSCs at S stage decreased in the 1.0/10.0/100.0/1000.0 nmol/L experiment groups; the expressions of mTOR and p70-S6K1 proteins were reduced in the 1.0/10.0/100.0/1000.0 nmol/L experiment groups, while ALP activity, OC levels, calcium deposition, Co1-I protein expression and the mRNA expressions of OC and Co1-I were significantly increased. Suppression of mTOR signaling pathway by rapamycin could promote BMSCs differentiation into osteoblast in DS.

[RESEARCH PROGRESS OF SURGICAL SELECTION OF FUSION LEVELS FOR DEGENERATIVE SCOLIOSIS]

OBJECTIVE

To summarize the progress of the surgical selection of fusion levels for degenerative scoliosis.

METHODS

The domestic and foreign related literature about degenerative scoliosis, including clinical features, classification, surgical treatment, and the fused segment, was summarized.

RESULTS

Degenerative scoliosis is very complicated. Short segment fusion and long segment fusion are the main surgical types. The long segment fusion is better in terms of reconstructing the stability of spine; however, it has more related complications. The short segment fusion has been used widely in clinical, but it causes degenerative disease easily. W/AL value can be used to direct the selection of short or long segment fusion for degenerative scoliosis.

CONCLUSIONS

The key to success surgery is choosing reasonable fused segment. Now there is no unified selection standard. With more knowledge about degenerative scoliosis, greater development can be expected in the future.

Preventing proximal junctional failure in long segmental instrumented cases of adult degenerative scoliosis using a multilevel stabilization screw technique

BACKGROUND

The authors sought to demonstrate the safety and effectiveness of the multilevel stabilization screw (MLSS) technique in decreasing the incidence of proximal junctional failure in long segmental instrumented fusions for adult degenerative scoliosis.

METHODS

Institutional review board approval was obtained and all patients with adult spinal deformity who underwent the MLSS technique were analyzed. A neuro-radiologist and spine-focused neurosurgeon not involved with the surgical treatment performed radiographic analysis. Proximal junctional angle was defined as the caudal endplate of the upper instrumented vertebra (UIV) to the cephalad endplate of two supradjacent vertebrae above the UIV. The UIV is defined as the most cephalad vertebra completed captured by the instrumentation. Abnormal proximal junctional kyphosis (PJK) was defined as proximal junctional sagittal Cobb angle >10 degrees and proximal junction sagittal Cobb angle at least 10 degrees greater than the preoperative measurement. The presence of both is criteria necessary to be considered abnormal.

RESULTS

Twenty patients with degenerative scoliosis underwent the MLSS technique with the upper-instrumented vertebrae in the proximal thoracic spine. Fifteen patients met inclusion criteria with greater than 12 months radiographic and clinical follow up. Three patients were excluded due to lack of follow up imaging and two patients were excluded due to the inability to measure the UIV. Age range was 44-84 years with a mean of 66. Eleven of the 15 patients were over the age of 60 at the time of surgery. The male-to-female ratio was 4:11. Body mass index (BMI) range was 24-44 with a mean of 31.5 units. The follow up period ranged from 14 to 58 months with an average follow up of 30 months. The mean change in Cobb angle at the proximal junction was 4.00 degrees with a range from -0.92 to 9.13 degrees. There were no fractures or instrumentation failures at or near the proximal junction. There was no revision surgeries performed for proximal junctional failure. Retrospective clinical questionnaires revealed that surgical expectations were met in 15 of 19 patients surveyed, 79%. One patient was not reachable for a postoperative phone interview. In patients who were not satisfied with their overall experience, the change in Cobb angle ranged from -0.92 to 9.13 degrees with an average change of 3.90 degrees. Whereas patients reporting an overall positive experience had a change in Cobb angle range from -0.12 to 8.07 degrees with an average change of 4.05 degrees.

CONCLUSION

PJK and failure are well-recognized suboptimal outcomes of long-segmental fusions of the thoracolumbar spine that can lead to significant neurological morbidity and costly revision surgeries. With no known proximal junction failures to date, the MLSS technique has shown promising results in preventing adverse proximal junctional conditions and can be safely performed under fluoroscopy guidance. Future direction includes a comparative study establishing the relative risk of developing PJK with this novel technique versus a traditional long-segmental thoracolumbar fusion.

Selection of proximal fusion level for degenerative scoliosis and the entailing proximal-related late complications

OBJECTIVE

To determine the optimal selection of proximal fusion level for degenerative scoliosis (DS) and investigate the long-term proximal-related complications.

METHODS

Profiles of 95 consecutive patients with DS who underwent posterior long instrumented fusion were analyzed retrospectively. Perioperative parameters were reviewed stratified into 3 groups according to the relationship between the upper instrumented vertebrae (UIV), horizontal vertebrae (HV) and upper end vertebrae (UEV), namely HV Group (UIV = HV or above), HV-UEV Group (UIV = between HV and UEV) and UEV Group (UIV = UEV or below) in coronal plane and 3 groups in sagittal plane according to segment levels. Clinical and radiographic parameters were studied statistically.

RESULTS

Average follow-up was 7.8 years (range, 5-13 years). HV Group showed a significant increase in operative time, intraoperative blood loss, postoperative in-bed time, and hospital stays. UEV Group showed greater average Cobb angle, AVT and DW. UEV Group showed significant increase in operative time, blood loss, postoperative in-bed time, and inpatient stay. All three groups showed significant improvement in ODI compared to baseline, while there was no significant difference in LL between three groups. Proximal-related late complications included recurrent junctional scoliosis in 4 cases and junctional kyphosis in 4 cases.

CONCLUSIONS

Recurrent junctional scoliosis developed more commonly when the fusion was at or below the UEV, and fusion at L1 or L2 showed the highest incidence of junctional kyphosis. Long instrumented fusion to T11 or T12 appeared to be a reasonable alternative when the UIV was above UEV in DS.

Adult Degenerative Scoliosis with Spinal Stenosis Treated with Stand-Alone Cage via an Extreme Lateral Transpsoas Approach; a Case Report and Literature Review

We report the case of a 73-year-old female with severe degenerative scoliosis and back and leg pain that was successfully treated with stand- alone cages via an extreme lateral transpsoas approach. This patient had declined open surgery and instrumentation due to her advanced age concerns about potential side effects.

Low expression of microRNA-143 is related to degenerative scoliosis possibly by regulation of cyclooxygenase-2 expression

AIMS

This study is to determine if expression level of microRNA-143 (miR-143) and cyclooxygenase-2 (COX-2) are related to the occurrence and development of degenerative scoliosis.

METHODS

A total of 30 patients with degenerative scoliosis, 30 patients with adolescent idiopathic scoliosis were enrolled in this study. For control, 30 patients with spinal burst fractures were also enrolled in this study. Real-time PCR and western blotting was performed to measure the expression levels of COX-2 in intervertebral disc tissues, peripheral blood and cerebrospinal. Expression levels of miR-143 in intervertebral disc tissues, peripheral blood and cerebrospinal were detected by real-time PCR.

RESULTS

The expression levels of COX-2 were increased in intervertebral disc tissues, peripheral blood and cerebrospinal of patients with degenerative scoliosis when compared with those of patients with adolescent idiopathic scoliosis and spinal burst fractures (P < 0.05). However, the expression levels of miR-143 were decreased in intervertebral disc tissues, peripheral blood and cerebrospinal of patients with degenerative scoliosis when compared with those of patients with adolescent idiopathic scoliosis and spinal burst fractures (P < 0.05).

CONCLUSIONS

COX-2 is highly expressed whereas miR-143 is lowly expressed in patients with degenerative scoliosis. Decreased expression of miR-143 may be related to the aggravation of degenerative scoliosis by regulation of COX-2.

Does preoperative narcotic use adversely affect outcomes and complications after spinal deformity surgery? A comparison of nonnarcotic- with narcotic-using groups

BACKGROUND CONTEXT

The role of preoperative (preop) narcotic use and its influence on outcomes after spinal deformity surgery are unknown. It is important to determine which patient factors and comorbidities can affect the success of spinal deformity surgery, a challenging surgery with high rates of complications at baseline.

PURPOSE

To evaluate if preop narcotic use persists after spinal deformity surgery and whether the outcomes are adversely affected by preop narcotic use.

STUDY DESIGN/SETTING

Retrospective evaluation of prospectively collected data.

PATIENT SAMPLE

Two hundred fifty-three adult patients (230 females/23 males) undergoing primary spinal deformity surgery were enrolled from 2000 to 2009.

OUTCOME MEASURES

Preoperative and postoperative (postop) narcotic use and changes in Oswestry Disability Index (ODI), Scoliosis Research Society (SRS) pain, and SRS total scores.

METHODS

Preoperative, 2-year postop, and latest follow-up pain medication use were collected along with ODI, SRS pain, and SRS scores. Preoperative insurance status, surgical and hospitalization demographics, and complications were collected. All patients had a minimum 2-year follow-up (average 47.4 months).

RESULTS

One hundred sixty-eight nonnarcotic (NoNarc) patients were taking no pain meds or only nonsteroidal anti-inflammatories preoperatively. Eighty-five patients were taking mild/moderate/heavy narcotics before surgery. The average age was 48.2 years for the NoNarc group versus 53.6 years for the Narc group (p<.005). There were significantly more patients with degenerative than adult scoliosis in the Narc group (47 vs. 28, p<.001; mild 19 vs. 24, p<.02; moderate 6 vs. 14, p<.0003; heavy 3 vs. 10, p<.0002). Insurance status (private/Medicare/Medicaid) was similar between the groups (p=.39). At latest follow-up, 137/156 (88%) prior NoNarc patients were still not taking narcotics whereas 48/79 (61%) prior narcotic patients were now off narcotics (p<.001). Significant postop improvements were seen in Narc versus NoNarc groups with regard to ODI (26-15 vs. 44-30.3, p<.001), SRS pain (3.36-3.9 vs. 2.3-3.38, p<.001), and overall SRS outcome (3.36-4 vs. 2.78-3.68, p<.001) scores. A comparison of change in outcome scores between the two groups showed a higher improvement in SRS pain scores for the Narc versus NoNarc group (p<.001).

CONCLUSIONS

In adults with degenerative scoliosis taking narcotics a significant decrease in pain medication use was noted after surgery. All outcome scores significantly improved postop in both groups. However, the Narc group had significantly greater improvements in SRS pain scores versus the NoNarc group.

Causes and managements of postoperative complications after degenerative scoliosis treatments with internal fixation

OBJECTIVE

To investigate the causes and managements of early postoperative complications of degenerative scoliosis (DS) treated with internal pedicle screw fixation.

METHODS

From Jan 2000 to Apr 2013, 325 DS patients treated with internal pedicle screw fixation in our hospital were retrospectively involved. The categories, causes, managements and outcomes of early postoperative complications were statistically analyzed.

RESULTS

Early postoperative complications occurred in 10.76% of the patients including 16 cases of lower limb numb or pain, 6 cases of decreased lower limb sensitivity and motor functions, which accounted for 62.86% of all complications, followed by incision infections (4/35, 11.43%) and rare cases of cerebrospinal fluid leakage, cardiac and renal inadequacy, urinary system and pulmonary infections. The incidence of overall complications (19.79%, p = 0.001) and nerve injuries (11.46%, p = 0.000) were significantly higher in long-segment than in short-segment fixations. Improper screw implanting, over correction of scoliosis and insufficient blood supply of the spinal cord during operation were risk factors for early postoperative complications and most of them were cured by anti-infection medication, incision dressing change, nerve nourishment, adjusting the screws and anti-osteoporosis treatments within 6 months after surgery. Only three cases with severe nerve injury did not improve until the 6 months postoperative follow-up.

CONCLUSIONS

Most of the postoperative complications in our DS patients disappeared within 6 months after surgery and more than half of complications were nerve injuries.

Adult Lumbar Degenerative Scoliosis 40° or Less: Outcomes of Surgical Treatment With Minimum 2-Year Follow-up

STUDY DESIGN

Longitudinal cohort.

OBJECTIVE

To determine the outcomes of operative treatment of adult lumbar degenerative scoliosis (ALDS) with Cobb angles of 40° or less.

SUMMARY OF BACKGROUND DATA

Some ALDS patients have curves less than 40°. Although these curves may not need correction, the curve may alter the treatment paradigm for associated back and leg pain, requiring fusion to achieve adequate decompression and prevent deformity progression.

METHODS

We reviewed hospital records and radiographs of 105 ALDS patients with curves from 10° to 40° who had decompression and instrumented fusion. We collected Oswestry Disability Index (ODI), Short Form-36 Physical (SF36 PCS), Mental Composite Scores (MCS), and back and leg pain scores preoperatively and 2 years postoperatively.

RESULTS

The 105 patients had a mean age of 64.0 years and body mass index of 28.8 kg/m². There were 26 smokers (23%). Preoperative symptoms included both back and leg pain in 94% (mean back pain = 7.8; mean leg pain = 7.0). Mean preoperative Cobb was 22.7° and mean lumbar lordosis was 39.8°. The most common curve apex was L2 (43%) and L3 (39%). An average of 3.0 ± 1.6 levels were decompressed and fused. Mean postoperative Cobb was 17.6° and mean lumbar lordosis was 36.5°. The ODI improved 14.9 points (48.5 vs. 33.6; p < .0001), SF36 PCS improved 6.2 points (27.9 vs. 34.1; p < .0001), and SF36 MCS improved 4.7 points (40.5 vs. 45.1; p < .0001). Back (7.8 vs. 4.1; p < .0001) and leg pain (7.0 vs. 3.1; p < .0001) also improved at 2-year follow-up compared with baseline.

CONCLUSIONS

Many ALDS patients present with problems associated with lumbar degenerative disease rather than severe deformity. and may require decompression for leg pain or neurogenic claudication. Even in patients with limited back pain, fusion is often needed, because decompression alone may result in either inadequate decompression or progression of the deformity. Results of this study indicate that ALDS patients with curves less than 40° benefit from decompression and fusion.