Comparison of Cobb angle measurements for scoliosis assessment using different imaging modalities: a systematic review.

Purpose: To report accuracy, repeatability, and agreement of Cobb angle measurements on radiographs and/or stereo-radiographs (EOS) compared against one another or against other imaging modalities. Methods: This review follows Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. A literature search was conducted on 21 July 2021 using Medline, Embase, and Cochrane. Two researchers independently performed title/abstract/full-text screening and data extraction. Studies were eligible if they reported Cobb angles, and/or their repeatability and agreement, measured on radiographs and/or EOS compared against one another or against other imaging modalities. Results: Of the 2993 records identified, 845 were duplicates and 2212 were excluded during title/abstract/full-text screening. Two more relevant studies were identified from references of eligible studies, leaving 14 studies for inclusion. Two studies compared Cobb angles from EOS vs CT, while 12 compared radiographs vs other imaging modalities: EOS, CT, MRI, digital fluoroscopy, or dual-energy x-ray absorptiometry. Angles from standing radiographs tended to be higher than those from supine MRI and CT, and angles from standing EOS tended to be higher than those from supine or prone CT. Correlations across modalities were strong (R = 0.78-0.97). Inter-observer agreement was excellent for all studies (ICC = 0.77-1.00), except one (ICC = 0.13 radiographs and ICC = 0.68 for MRI). Conclusion: Differences of up to 11º were found when comparing Cobb angles across combinations of imaging modalities and patient positions. It is not possible, however, to determine whether the differences observed are due to the change of modality, position, or both. Therefore, clinicians should be careful when utilizing the thresholds for standing radiographs across other modalities and positions for diagnosis and assessment of scoliosis.

SPINE: High heterogeneity and no significant differences in clinical outcomes of endoscopic foraminotomy vs fusion for lumbar foraminal stenosis: a meta-analysis.

Objective: This study aimed to systematically review the literature for comparative and non-comparative studies reporting on clinical outcomes of patients with lumbar foraminal stenosis treated by either endoscopic foraminotomy or fusion. Methods: In adherence with Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, a literature search was done on January 17, 2022, using Medline and Embase. Clinical studies were eligible if they reported outcomes following fusion or endoscopic foraminotomy, in patients with primary lumbar foraminal stenosis. Two independent reviewers screened titles, abstracts, and full-texts to determine eligibility; performed data extraction; and assessed the quality of eligible studies according to the Joanna Briggs Institute (JBI) checklist. Results: The search returned 827 records; 266 were duplicates, 538 were excluded after title/abstract/full-text screening, and 23 were eligible, with 16 case series reporting on endoscopic foraminotomy, 7 case series reporting on fusion, and no comparative studies. The JBI checklist indicated that 21 studies scored ≥4 points. When comparing endoscopic foraminotomy to fusion, pooled data revealed reduced operative time (69 vs 119 min, P < 0.01) but similar Oswestry disability index (19 vs 20, P = 0.67), lower back pain (2 vs 2, P = 0.11), leg pain (2 vs 2, P = 0.15), complication rates (10% vs 5%, P = 0.22), and reoperation rates (5% vs 0%, P = 0.16). The proportions of patients with good/excellent MacNab criteria were similar for endoscopic foraminotomy and fusion (82-91% vs 85-91%). Conclusions: There were high heterogeneity and no significant differences in clinical outcomes, complication rates, and reoperation rates between endoscopic foraminotomy and fusion for the treatment of lumbar foraminal stenosis; although endoscopic foraminotomy has reduced operative time.

Surgical management of isthmic spondylolisthesis: A comparative study of postoperative outcomes between ALIF and TLIF.

INTRODUCTION: Circumferential fusion by the anterior (ALIF) or transforaminal (TLIF) approach combined with posterior instrumentation is currently used for the surgical treatment of low-grade isthmic spondylolisthesis. But few studies have compared the clinical and radiological outcomes of various interbody fusion techniques. The objective of this study was to compare the clinical and radiological results at 2 years postoperative of two fusion techniques-TLIF versus ALIF plus posterior instrumentation-for low-grade isthmic spondylolisthesis in adults. MATERIALS AND METHODS: This was an observational multicenter study done at nine French healthcare facilities specialized in spine surgery. The inclusion criteria were minimum age of 18 years, grade 1-3 isthmic spondylolisthesis, ALIF+posterior fixation (ALIF+PS) or TLIF, minimum follow-up of 2 years. Clinical and radiological evaluations were done preoperatively and at 2 years of follow-up. A lumbar CT scan was done at 1 year postoperative to evaluate fusion. RESULTS: The cohort consisted of 89 patients (50 women, 39 men) with a mean age of 47.7±12.3 (18-79) years. The patients in the ALIF groups (n=71) had a significantly longer hospital stay than those in the TLIF group (n=18): 5.7 days versus 4.6 days (p=.04). However, their medical leave from work was significantly shorter: 31.0 weeks versus 40.7 (p=.003). Lumbar pain VAS diminished faster in the ALIF groups, with a significantly larger drop than the TLIF group in the first 3 months postoperative. Only the increase in lumbar disc lordosis was larger in the ALIF group: 11.7°±12.0° versus 6.0°±11.7° (p=.036). There was a significant correlation between the increase in global lordosis and reduction in lumbar VAS at 2 years postoperative (ρ=-0.3295; p=.021). CONCLUSION: ALIF+PS provides a faster relief of postoperative low back pain than TLIF but there are no significant clinical differences between techniques at 2 years of follow-up. Despite better restoration of disc lordosis in the ALIF+PS group, there was no difference in the restoration of global lordosis. LEVEL OF EVIDENCE: III; multicenter comparative study.

Implications of cage impactions in single-level OLIF treatment of degenerative spondylolisthesis.

INTRODUCTION: Cage impactions (CI) of Oblique Lumbar Interbody Fusion (OLIF) appear to be a frequent mechanical complication with a potential functional impact. OBJECTIVES: To determine the rate of CI occurrence, their risk factors and clinical implications in the case of combined single-level arthrodesis. METHOD: A retrospective analysis of prospectively collected data was performed. All our patients with degenerative spondylolisthesis initially underwent OLIF combined with pedicle screw fixation (PSF). Intraoperative control with an image intensifier and a standard radiograph in the immediate postoperative period made it possible to assess the occurrence of CI, depending on the position of the implant. Secondary subsidence was sought on the standing radiological examination using EOS biplanar radiography during follow-up. The pelvic parameters were analyzed, as well as the occurrence of bone fusion. The clinical evaluation was made at≥1 year, by the Oswestry Disability Index (ODI), the walking distance (WD) and the Visual Analogue Scale (VAS). RESULTS: In all, 130 patients out of the 131 included were analyzed. A CI occurred in 25.3% (n=33) of cases and of these, 94% (n=32) occurred intraoperatively. Postmenopausal women had more CI with an odds ratio (OR) of 5.8 (P=0.034). The "CI" group had a 9.5% lower ODI score than the "non-CI" group (P=0.0040), but both provided excellent ODI gains of 30.8±16 and 32.9±15.5% (P<0.0001). An "anterior" position of the implant allowed a greater gain in lumbar lordosis (P<0.001) but was associated with greater CI occurrence (P<0.001), with an OR of 6.75 (P=0.0018). CONCLUSION: The occurrence of intraoperative cage impaction is a frequent event when performing OLIF. Postmenopausal women have an approximately 6 times greater risk of impaction than men, and patients with an "anterior" implant placement have a 7 times greater risk than with central placement. The negative impact of cage impactions on the clinical score (ODI) was significant after one year of follow-up. LEVEL OF EVIDENCE: IV, non-comparative cohort study.

Fusion and clinical outcomes of lumbar interbody fusion for low-grade isthmic spondylolisthesis.

INTRODUCTION: Low-grade isthmic spondylolisthesis (ISPL) is generally treated by circumferential fusion with interbody graft, although there is no consensus on technique. HYPOTHESIS: The various interbody fusion strategies provide satisfactory fusion rates and clinical results. METHODS: A multicenter retrospective study analyzed lumbar interbody fusion for low-grade ISPL performed between March 2016 and March 2019. Techniques comprised: circumferential fusion on a posterior or a transforaminal approach (PLIF, TLIF: n=57), combined anterior (ALIF)+posterolateral fusion (ALIF+PLF: n=60), and ALIF+percutaneous posterior fixation (ALIF+PPF: n=55). Function was assessed on a lumbar and a radicular visual analog scale (AVS-L, VAS-R), Oswestry Disability Index (ODI) and Short Form 12 (SF12). RESULTS: Among the 129 patients, 85.3% showed fusion (Lenke 1 or 2), with no significant differences between the ALIF-PLF or ALIF-PPF groups and the PLIF or TLIF groups (p=0.3). Likewise, there was no difference in fusion rates between the ALIF-PPF and ALIF-PLF subgroups (p=0.28). VAS-L (p<0.001) and VAS-R (p<0.0001), ODI (p<0.001) and SF12 physical (PCS) (p<0.01) and mental component sores (MCS) (p<0.001) all showed significant improvement at 12months. Combined approaches provided greater clinical efficacy than TLIF or PLIF for lumbar (p<0.0001) and radicular pain (p<0.05), ODI (p<0.0001) and SF12 PCS (p<0.01). At 12months, there was no clinical difference between the ALIF-PPF and ALIF-PLF subgroups. However, patents with interbody non-union (Lenke 3 or 4) had lower SF12 PCS scores (p<0.004) and VAS-L ratings (p<0.001) than Lenke 1-2 patients. CONCLUSION: Low-grade ISPL treated by circumferential arthrodesis and interbody graft showed 85.3% consolidation at 2years, with equivalent outcomes between anterior and posterior techniques. Successful fusion was associated with better clinical results. LEVEL OF EVIDENCE: IV.

Bioactive glass grants equivalent fusion compared to autologous iliac crest bone for ALIF: a within-patient comparative study.

PURPOSE: To determine within-patient fusion rates of chambers filled with bioactive glass versus autologous iliac crest bone on computed tomography (CT) following anterior lumbar interbody fusion (ALIF). METHODS: A consecutive series of 40 patients (58 levels) that underwent single-level (L5-S1 only) or two-level (L5-S1 and L4-L5) ALIF were assessed. Indications for fusion were one or more of the following: degenerative disc disease with or without Modic changes, spondylolisthesis, and stenosis. Each intervertebral cage had a middle beam delimiting two chambers, one of which was filled with bioactive glass and the other with autologous iliac crest bone. CT scans were graded using the Bridwell classification (grade I, best; grade IV, worst). Patients were evaluated using the Oswestry Disability Index (ODI), and by rating pain in the lower back and legs on a Visual Analog Scale (pVAS); complications and reoperations were noted. RESULTS: At 15 ± 5 months follow-up, there were no significant differences in fusion across chambers filled with bioactive glass versus chambers filled with autologous bone (p = 0.416). Two patients with Bridwell grade III at both chambers of the L4-L5 cages required reoperation using posterior instrumentation. Clinical assessment of the 38 remaining patients (54 levels) at 25 ± 2 months, revealed ODI of 15 ± 12, lower back pVAS of 1.4 ± 1.5 and legs pVAS of 1.9 ± 1.6. CONCLUSIONS: For ALIF at L5-S1 or L4-L5, within-patient fusion rates were equivalent for bioactive glass compared to autologous iliac crest bone; thus, bioactive glass can substitute autologous bone, avoiding increased operative time and blood loss, as well as donor site morbidity.

Comparison of four correction techniques for posterior spinal fusion in adolescent idiopathic scoliosis.

INTRODUCTION: When performing posterior spinal fusion for adolescent idiopathic scoliosis (AIS), it is of major importance to address both coronal and sagittal deformities. Although several techniques have been described, few data exist comparing them. Our objective was to compare four techniques (in situ bending (ISB), rod derotation (RD), cantilever (C) and posteromedial translation (PMT)) for the correction of spinal deformity in AIS including thoracic deformity. MATERIAL AND METHODS: We conducted a multicenter retrospective study including 562 AIS patients with thoracic deformity with at least 24-month follow-up. Radiographic analysis was performed preoperatively, postoperatively and at last follow-up. The main outcomes were main curve correction and thoracic kyphosis restoration (TK). RESULTS: Coronal correction rate was significantly different among the four treatment groups (ISB 64% vs C 57% vs RD 55% vs PMT 67%, p < 0.001). Multivariate regression revealed that correction technique did not influence correction rate, whereas implant density, convex side compression and use of derotation connectors did. TK increase was significantly higher in the PMT group (average + 13°) than in DR (+ 3°), while ISB (-3°) and cantilever (-13°) resulted in TK decrease (p < 0.001). Multivariate analysis revealed that TK increase was only influenced by the reduction technique (p < 0.001) and preoperative TK (p < 0.001). DISCUSSION: The four techniques had the same ability to correct spinal deformity in the coronal plane. Three factors were identified to improve correction rate: implant density, convex compression and use of derotation connectors. On the other hand, PMT was more effective in restoring TK, particularly in hypokyphotic patients.

Postoperative pain due to an occult spinal infection: A case report.

BACKGROUND: A high degree of vigilance is warranted for a spinal infection, particularly in a patient who has undergone an invasive procedure such as a spinal injection. The average delay in diagnosing a spinal infection is 2-4 mo. In our patient, the diagnosis of a spinal infection was delayed by 1.5 mo. CASE SUMMARY: A 60-year-old male patient with a 1-year history of right-sided lumbar radicular pain failed conservative treatment. Six weeks to prior to surgery he received a spinal injection, which was followed by increasing lumbar radicular pain, weight loss and chills. This went unnoticed and surgery took place with right-sided L4-L5 combined microdiscectomy and foraminotomy via a posterior approach. The day after surgery, the patient developed left-sided lumbar radicular pain. Blood cultures grew Staphylococcus aureus (S. aureus). Magnetic resonance imaging showed inflammatory aberrations, revealing septic arthritis of the left-sided L4/L5 facet joint as the probable cause. Revision surgery took place and S. aureus was isolated from bacteriological samples. The patient received postoperative antibiotic treatment, which completely eradicated the infection. CONCLUSION: The development of postoperative lower back pain and/or lumbar radicular pain can be a sign of a spinal infection. A thorough clinical and laboratory work-up is essential in the preoperative evaluation of patients with spinal pain.

Proximal junctional kyphosis is a rebalancing spinal phenomenon due to insufficient postoperative thoracic kyphosis after adolescent idiopathic scoliosis surgery.

PURPOSE: Many authors tried to explain proximal junctional kyphosis (PJK) after adolescent idiopathic scoliosis (AIS) surgery by looking for risk factors. Latest publications focus on sagittal alignment. Each healthy adolescent has a specific thoracic kyphosis (TK) depending on their pelvic parameters and lumbar lordosis (LL). The objective of this work is to determine if the difference between TK at follow-up (TKFU) and the patient-specific TK (PSTK) plays a role in PJK occurrence after AIS surgery. The secondary objective was to find other risk factors. METHODS: We analyzed retrospectively 570 thoracic AIS who underwent a posterior thoracic fusion from nine centers. The series was separated in two groups: with and without PJK. PSTK was calculated with the formula PSTK = 2(PT + LL-PI). TK Gap was the difference between TKFU and PSTK. Logistic regression was utilized to test the impact of TK Gap and other known risk factors on PJK occurrence. RESULTS: Univariate analysis showed 15 factors significantly different between the groups. In a multivariate analysis, three factors had a strong significant influence on PJK: TKFU, TK Gain and TK Gap. Four additional factors affected the rate of PJK: Posterior translation on two rods, preoperative TK, preoperative LL and number of instrumented vertebrae. CONCLUSION: PJK is related to the insufficient TK at follow-up, compared to the specific TK that every patient should have according to their pelvic parameters. PJK incidence is significantly reduced by a strong gain in TK and a thoracic selective fusion which leaves the proximal lumbar vertebrae free. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Management of Incidental Durotomy: Results from a Nationwide Survey Conducted by the French Society of Spine Surgery.

OBJECTIVE: To obtain real-life data on the most common practices used for management of incidental durotomy (ID) in France. METHODS: Data were collected from spinal surgeons using a practice-based online questionnaire. The survey comprised 31 questions on the current management of ID in France. The primary outcome was the identification of areas of consensus and uncertainty on ID follow-up. RESULTS: A total of 217 surgeons (mainly orthopaedic surgeons and neurosurgeons) completed the questionnaire and were included in the analysis. There was a consensus on ID repair with 94.5% of the surgeons considering that an ID should always be repaired, if repairable, and 97.2% performing a repair if an ID occurred. The most popular techniques were simple suture or locked continuous suture (48.3% vs. 57.8% of surgeons). Nonrepairable IDs were more likely to be treated with surgical sealants than with an endogenous graft (84.9% vs. 75.5%). Almost two thirds of surgeons (71.6%) who adapted their standard postoperative protocol after an ID recommended bed rest in the supine position. Among these, 48.8% recommended 24 hours of bed rest, while 53.5% recommended 48 hours of bed rest. The surgeons considered that the main risk factors for ID were revision surgery (98.6%), patient's age (46.8%), surgeon's exhaustion (46.3%), and patient's weight (21.3%). CONCLUSIONS: This nationwide survey reflects the lack of a standardized management protocol for ID. Practices among surgeons remain very heterogeneous. Further consensus studies are required to develop a standard management protocol for ID.

Enhanced recovery after surgery (ERAS) protocol reduces LOS without additional adverse events in spine surgery.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols aim to reduce the physiological stress induced by surgery. These protocols are persistently associated with improved outcomes and reduced costs in several orthopaedic subspecialties. Recently, spine surgery has been explored in the literature as a potential and beneficial domain for ERAS protocols. The aim of this study was to compare the short-term postoperative spine surgery follow-up between patients who underwent the ERAS protocol and those who recovered conventionally. HYPOTHESIS: The ERAS protocol developed in our department since 2016 is beneficial to patients undergoing spinal surgery. PATIENTS AND METHODS: A retrospective analysis of data collected prospectively was performed to include all patients who underwent spinal surgery and went through the ERAS protocol in our clinic between January 2017 and January 2018. A control group was paired using a propensity score. Length of hospital stay (LOS), complications, rate of readmissions, postoperative pain, function and satisfaction were compared between the two groups. RESULTS: A total of 193 patients received the ERAS protocol during the study period. After pairing, 193 couples were selected resulting in a final database of 386 patients for the analysis. There was a significant difference in mean LOS, defined as the average number of days spent in hospital, between the two groups (ERAS group, mean LOS=2.6 days [median 2 days, range 1-7], control group mean LOS=4.4 days [median 4 days, range 2-14]; p<0.0001). Complications, rate of readmissions, postoperative pain, function and satisfaction were similar in the two groups. DISCUSSION: The ERAS protocol decreased hospital LOS, without resulting in additional adverse events after spinal surgery. These findings support the application of our ERAS protocol after spinal surgery. LEVEL OF EVIDENCE: III, retrospective analysis.

Outcomes of stand-alone anterior lumbar interbody fusion of L5-S1 using a novel implant with anterior plate fixation.

BACKGROUND CONTEXT: Compared with other approaches, anterior lumbar interbody fusion (ALIF) is believed to be more effective at restoring segmental lordosis and reducing risks of adjacent-segment disease. It remains controversial, however, whether ALIF improves global lumbar lordosis or influences pelvic parameters, possibly because of the heterogeneity of implants and levels studied. PURPOSE: To report clinical outcomes of stand-alone ALIF with anterior plate fixation for L5-S1 and to determine the effect on global lumbar lordosis and pelvic parameters. STUDY DESIGN: This is a retrospective case series. PATIENT SAMPLE: Patients that underwent isolated mini-ALIF with anterior plate fixation for L5-S1. OUTCOME MEASURES: Oswestry Disability Index (ODI), Short Form 12, lower back and legs pain on Visual Analog Scale, as well as spino-pelvic parameters. METHODS: The authors reviewed the records of all patients that underwent retroperitoneal mini-ALIF for single-level L5-S1 fusion between August 2012 and December 2016. A total of 129 patients were included, but 9 patients had incomplete preoperative radiographic data, and one patient had schizophrenia and was unable to respond to outcome questionnaires, leaving 119 patients eligible for outcome assessment. At a minimum follow-up of 1 year, seven patients refused to participate in the study or could not be reached, which left a final cohort of 112 patients. RESULTS: Nine patients were reoperated without implant removal (four pseudarthrosis, two hematomas, one sepsis, one L4-L5 disc hernia, and one L4-L5 disc degeneration). At a mean of 20±9 months, all scores improved significantly from baseline values, with net improvement in ODI of 23.3±19.9. Multivariable analyses confirmed better postoperative ODI in patients that received 18° cages (ß=-9.0, p=.017), but revealed no significant trends for net improvement in ODI. Comparison of preoperative and last follow-up radiographs revealed that global lumbar lordosis increased by 4.2±7.1° (p<.001), L5-S1 segmental lordosis increased by 11.8±6.7° (p<.001), and L4-L5 segmental lordosis decreased by 1.9±3.3° (p<.001). All pelvic parameters changed: pelvic incidence increased by 0.6±2.7° (p=.003), pelvic tilt decreased by 2.5±4.1° (p<.001) and sacral slope increased by 3.3±4.7° (p<.001). CONCLUSIONS: Stand-alone mini-ALIF with anterior plate fixation for L5-S1 can change pelvic parameters while improving global and segmental lumbar lordosis. The procedure resulted in a fusion rate of 96% and comparable improvements in ODI to other studies.

rhBMP-2 (Recombinant Human Bone Morphogenetic Protein-2) in real world spine surgery. A phase IV, National, multicentre, retrospective study collecting data from patient medical files in French spinal centres.

BACKGROUND: This is a Phase IV, national, multicentre, retrospective study to observe the real-world use of rhBMP-2 in France. HYPOTHESIS: There was no statistical hypothesis, the statistical analyses were descriptive in nature. PATIENTS AND METHODS: Data was collected from patient medical files in 10 French spinal centres. Primary objectives were to understand which patients were treated with rhBMP-2, commercialised in Europe as InductOs™ and how rhBMP-2 was used during spinal fusion surgery in France between 2011 and 2012. RESULTS: Four hundred patients (634 levels) treated with rhBMP-2 were included in the analysis. The most frequent primary diagnostic indication for rhBMP-2 use was degenerative disc disease (DDD; 129/400; 32.3% of patients) followed by spondylolisthesis (119/400; 29.8%), deformity (59/400; 14.8%) and pseudoarthrosis (29/400; 7.3%). The most frequently treated level was L4-L5 (33.8% of levels in 53.5% of patients); followed by L5-S1 (29.8%, 47.3%), L3-L4 (16.7%, 26.5%), and L2-L3 (7.3%, 11.5%), all other levels (less than 5% of patients). No interbody fusion device was used in 42.7% of levels. Wetted matrix of rhBMP-2 was placed in the interbody space in 58.4% of levels (370/634). The most common procedure for rhBMP-2 treatment was posterior lumbar fusion (PLF) (221/634; 34.9% of levels), followed by anterior lumbar interbody fusion (ALIF) (188/634; 29.7%), posterior lumbar interbody fusion (PLIF) (111/634; 17.5%), lateral lumbar interbody fusion (LLIF) (106/634; 16.7%), transforaminal lumbar interbody fusion (TLIF) (4/634; 0.6%) and 'other' (4/634; 0.6%). Thirty-one adverse events of Interest (AEI) were recorded in 27 patients. One AEI was considered related to rhBMP-2. Unplanned secondary spine interventions at index level treated with rhBMP-2 were required in 4 patients. DISCUSSION: In years 2011 and 2012 when the surgeries captured in this retrospective study were done, rhBMP-2 was indicated for single level (L4-S1) anterior lumbar spine fusion as a substitute for autogenous bone graft in adults with DDD. The most common procedure for the treatment with rhBMP-2 was PLF (off-label use), followed by ALIF (on-label use). The safety findings confirm a predictable and manageable safety profile. LEVEL OF EVIDENCE: IV.