Faculty Bibliography

OBJECT/OBJECTIVE:The LSDI assesses the impact of lumbar stiffness on activities of daily living. We hypothesized that patients <60 years-old would perceive greater lumbar stiffness-related functional limitation following fusion for adult spinal deformity. METHODS:Patients completed the LSDI and SRS-22r questionnaires preoperatively and at 2 years postoperatively. The primary independent variable was patient age <60 vs. ≥60 years-old. Multivariable regression analyses were utilized. RESULTS:In total, 267 patients were analyzed. Patients <60 years-old (51.3%) and ≥60 years-old (48.7%) were evenly represented. In bivariable analysis, patients <60 years-old exhibited lower LSDI at baseline vs. patients ≥60 years-old (25.7 vs. 35.5, β -9.8, p<0.0001), but a directionally smaller difference at 2-years (26.4 vs. 32.3, β -5.8, p=0.0147). LSDI was associated with lower SRS-22r total score among both patients <60 and ≥60 years-old, at both baseline and 2-years (all p<0.0001); the association was stronger among patients <60 vs. ≥60 years-old at 2 years. LSDI was associated with SRS satisfaction scores at 2 years among patients <60 years-old (p<0.0001), but not patients ≥60 years-old (p=0.2250). The difference in SRS satisfaction per unit LSDI between patients <60 years-old and >60 years-old was significant (p=0.0021). CONCLUSIONS:Among ASD patients managed operatively, higher LSDI was associated with inferior SRS-22r total score and satisfaction at 2 years postoperatively. The association between increased LSDI and worse PROMs was greater among patients <60 vs. ≥60 years old. Pre-operative counseling is needed for patients <60 undergoing ASD surgery regarding the effects that lumbar stiffness may have on post-operative function and satisfaction.

The AHRQ (Agency for Healthcare Research and Quality) has requested the correction of the result Tables 1-3 of this study: All stated numbers below 10 shall be modified to read "<10" instead.

STUDY DESIGN/METHODS:Multicenter database review of consecutive adult spinal deformity (ASD) patients. OBJECTIVE:The aim of this study was to identify associations between changes in spinopelvic parameters and cervical alignment after thoracolumbar arthrodesis for ASD. SUMMARY OF BACKGROUND DATA/BACKGROUND:Reciprocal cervical changes occur after instrumented thoracic spinal arthrodesis. The timing and relationship of these changes to sagittal alignment and upper instrumented vertebra (UIV) selection are unknown. METHODS:In 171 ASD patients treated with thoracolumbar arthrodesis from 2008 to 2012, we assessed changes from baseline to 6-week, 1-year, and 2-year follow-up in C2-C7 sagittal vertical axis (SVA), T1 slope, and C2-C7 lordosis. We used multivariate models to analyze associations between these parameters and UIV selection (T9 or distal vs. proximal to T9) and changes at each time point in thoracic kyphosis (TK), lumbar lordosis (LL), C7-S1 SVA, pelvic incidence, pelvic tilt, and sacral slope. RESULTS:Two-year changes in C2-C7 SVA and T1 slope were significantly associated with baseline to 6-week changes in TK and LL and with UIV selection. Baseline to 2-year changes in C2-C7 lordosis were associated with baseline to 6-week changes in C7-S1 SVA (P = 0.004). Most changes in C2-C7 SVA occurred during the first 6 weeks postoperatively (mean 6-week change in C2-C7 SVA: 2.7 cm, 95% confidence interval [CI]: 0.7-4.7 cm; mean 2-year change in SVA: 2.3 cm, 95% CI: -0.1 to 4.6 cm). At 2 years, on average, there was decrease in C2-C7 lordosis, most of which occurred during the first 6 weeks postoperatively (mean 6-week change: -3.2°, 95% CI: -4.8° to -1.2°; mean 2-year change: -1.3°, 95% CI: - 3.2° to 0.5°). CONCLUSION/CONCLUSIONS:After thoracolumbar arthrodesis, reciprocal changes in cervical alignment are associated with postoperative changes in TK, LL, and C7-S1 SVA and with UIV selection. The largest changes occur during the first 6 weeks and persist during 2-year follow-up. LEVEL OF EVIDENCE/METHODS:3.

OBJECTIVE:Cervical deformity (CD) is difficult to define due to the high variability in normal cervical alignment based on postural- and thoracolumbar-driven changes to cervical alignment. The purpose of this study was to identify whether patterns of sagittal deformity could be established based on neutral and dynamic alignment, as shown on radiographs. METHODS:This study is a retrospective review of a prospective, multicenter database of CD patients who underwent surgery from 2013 to 2015. Their radiographs were reviewed by 12 individuals using a consensus-based method to identify severe sagittal CD. Radiographic parameters correlating with health-related quality of life were introduced in a two-step cluster analysis (a combination of hierarchical cluster and k-means cluster) to identify patterns of sagittal deformity. A comparison of lateral and lateral extension radiographs between clusters was performed using an ANOVA in a post hoc analysis. RESULTS:Overall, 75 patients were identified as having severe CD due to sagittal malalignment, and they formed the basis of this study. Their mean age was 64 years, their body mass index was 29 kg/m2, and 66% were female. There were significant correlations between focal alignment/flexibility of maximum kyphosis, cervical lordosis, and thoracic slope minus cervical lordosis (TS-CL) flexibility (r = 0.27, 0.31, and -0.36, respectively). Cluster analysis revealed 3 distinct groups based on alignment and flexibility. Group 1 (a pattern involving a flat neck with lack of compensation) had a large TS-CL mismatch despite flexibility in cervical lordosis; group 2 (a pattern involving focal deformity) had focal kyphosis between 2 adjacent levels but no large regional cervical kyphosis under the setting of a low T1 slope (T1S); and group 3 (a pattern involving a cervicothoracic deformity) had a very large T1S with a compensatory hyperlordosis of the cervical spine. CONCLUSIONS:Three distinct patterns of CD were identified in this cohort: flat neck, focal deformity, and cervicothoracic deformity. One key element to understanding the difference between these groups was the alignment seen on extension radiographs. This information is a first step in developing a classification system that can guide the surgical treatment for CD and the choice of fusion level.

OBJECTIVE:Cervical deformity (CD) correction is clinically challenging. There is a high risk of developing complications with these highly complex procedures. The aim of this study was to use baseline demographic, clinical, and surgical factors to predict a poor outcome following CD surgery. METHODS:The authors performed a retrospective review of a multicenter prospective CD database. CD was defined as at least one of the following: cervical kyphosis (C2-7 Cobb angle > 10°), cervical scoliosis (coronal Cobb angle > 10°), C2-7 sagittal vertical axis (cSVA) > 4 cm, or chin-brow vertical angle (CBVA) > 25°. Patients were categorized based on having an overall poor outcome or not. Health-related quality of life measures consisted of Neck Disability Index (NDI), EQ-5D, and modified Japanese Orthopaedic Association (mJOA) scale scores. A poor outcome was defined as having all 3 of the following categories met: 1) radiographic poor outcome: deterioration or severe radiographic malalignment 1 year postoperatively for cSVA or T1 slope-cervical lordosis mismatch (TS-CL); 2) clinical poor outcome: failing to meet the minimum clinically important difference (MCID) for NDI or having a severe mJOA Ames modifier; and 3) complications/reoperation poor outcome: major complication, death, or reoperation for a complication other than infection. Univariate logistic regression followed by multivariate regression models was performed, and internal validation was performed by calculating the area under the curve (AUC). RESULTS:In total, 89 patients with CD were included (mean age 61.9 years, female sex 65.2%, BMI 29.2 kg/m2). By 1 year postoperatively, 18 (20.2%) patients were characterized as having an overall poor outcome. For radiographic poor outcomes, patients' conditions either deteriorated or remained severe for TS-CL (73% of patients), cSVA (8%), horizontal gaze (34%), and global SVA (28%). For clinical poor outcomes, 80% and 60% of patients did not reach MCID for EQ-5D and NDI, respectively, and 24% of patients had severe symptoms (mJOA score 0-11). For the complications/reoperation poor outcome, 28 patients experienced a major complication, 11 underwent a reoperation, and 1 had a complication-related death. Of patients with a poor clinical outcome, 75% had a poor radiographic outcome; 35% of poor radiographic and 37% of poor clinical outcome patients had a major complication. A poor outcome was predicted by the following combination of factors: osteoporosis, baseline neurological status, use of a transition rod, number of posterior decompressions, baseline pelvic tilt, T2-12 kyphosis, TS-CL, C2-T3 SVA, C2-T1 pelvic angle (C2 slope), global SVA, and number of levels in maximum thoracic kyphosis. The final model predicting a poor outcome (AUC 86%) included the following: osteoporosis (OR 5.9, 95% CI 0.9-39), worse baseline neurological status (OR 11.4, 95% CI 1.8-70.8), baseline pelvic tilt > 20° (OR 0.92, 95% CI 0.85-0.98), > 9 levels in maximum thoracic kyphosis (OR 2.01, 95% CI 1.1-4.1), preoperative C2-T3 SVA > 5.4 cm (OR 1.01, 95% CI 0.9-1.1), and global SVA > 4 cm (OR 3.2, 95% CI 0.09-10.3). CONCLUSIONS:Of all CD patients in this study, 20.2% had a poor overall outcome, defined by deterioration in radiographic and clinical outcomes, and a major complication. Additionally, 75% of patients with a poor clinical outcome also had a poor radiographic outcome. A poor overall outcome was most strongly predicted by severe baseline neurological deficit, global SVA > 4 cm, and including more of the thoracic maximal kyphosis in the construct.

It's increasingly common for surgeons to operate on more challenging cases and higher risk patients, resulting in longer op-time and inpatient LOS. Factors predicting extended op-time and LOS for cervical deformity (CD) patients are understudied. This study identified predictors of extended op-time and length of stay (LOS) after CD-corrective surgery. CD patients with baseline (BL) radiographic data were included. Patients were stratified by extended LOS (ELOS; >75th percentile) and normal LOS (N-LOS; <75th percentile). Op-time analysis excluded staged cases, cases >12 h. A Conditional Variable Importance Table used non-replacement sampling set of Conditional Inference trees to identify influential factors. Mean comparison tests compared LOS and op-time for top factors. 142 surgical CD patients (61 yrs, 62%F, 8.2 levels fused). Op-time and LOS were 358 min and 7.2 days; 30% of patients experienced E-LOS (14 ± 13 days). Overlapping predictors of E-LOS and op-time included levels fused (>7 increased LOS 2.7 days; >5 increased op-time 96 min, P < 0.001), approach (anterior reduced LOS 3.0 days; combined increased op-time 69 min, P < 0.01), BMI (>38 kg/m² increased LOS 8.1 days; >39 kg/m² increased op-time 17 min), and osteotomy (LOS 2.0 days, op-time 62 min, P < 0.005). BL cervical parameters increased LOS and op-time: cSVA (>42 mm increased LOS; >50 mm increased op-time, P < 0.030), C0 slope (>@-0.9° increased LOS, >0.3° increased op-time, P < 0.003.) Additional op-time predictors: prior cervical surgery (p = 0.004) and comorbidities (P = 0.015). Other predictors of E-LOS: EBL (P < 0.001), change in mental status (P = 0.001). Baseline cervical malalignment, levels fused, and osteotomy predicted both increased op-time and LOS. These results can be used to better optimize patient care, hospital efficiency, and resource allocation.

OBJECTIVE:In the setting of a previous proximal fusion, an asymmetric 3-column osteotomy (3CO) can provide tremendous deformity correction. Our goal was to evaluate outcomes and complications of asymmetric 3CO through the proximal fusion mass, for coronal malalignment in patients with previous long thoracic fusion for adolescent idiopathic scoliosis. METHODS:This was a retrospective case series. Thirteen individuals with a history of a long thoracic fusion underwent asymmetric 3CO for persistent coronal malalignment. Clinical chart review was conducted to determine perioperative complications and radiographs evaluated for alignment. RESULTS:Thirteen patients (age: 57.8 ± 12.2 years; 0 male, 13 female) completed a mean follow-up of 42.4 months. There was significant improvement in coronal and sagittal alignment, and pelvic incidence-lumbar lordosis postoperatively (P < 0.05). One patient developed lower-extremity weakness requiring revision decompression 72 hours postoperatively; the weakness subsequently resolved. One patient had a foot drop postoperatively. At final follow-up, 12 of 13 patients had grade 1 fusion at the osteotomy site; 1 patient had a grade 2 fusion. None of the patients developed a pseudarthrosis, or superficial or deep infections. CONCLUSIONS:Patients with a history of previous thoracic fusion for adolescent idiopathic scoliosis and coronal malalignment may develop painful degeneration of the segments caudal to the fusion as adults. In this setting, extension of fusion to the sacropelvis alone may worsen the patient's coronal alignment. An asymmetric 3CO may be considered at the proximal fusion mass to achieve realignment objectives, with an acceptable complication rate and an expected improvement in outcomes.

STUDY DESIGN:Retrospective review from a single institution. OBJECTIVE:To investigate the effect of hip osteoarthritis (OA) on spinopelvic compensatory mechanisms as a result of reduced hip range of motion (ROM) between sitting and standing. SUMMARY OF BACKGROUND DATA:Hip OA results in reduced hip ROM and contracture, causing pain during postural changes. Hip flexion contracture is known to reduce the ability to compensate for spinal deformity while standing; however, the effects of postural spinal alignment change between sitting and standing is not well understood. METHODS:Sit-stand radiographs of patients without prior spinal fusion or hip prosthesis were evaluated. Hip OA was graded by Kellgren-Lawrence grades and divided into low-grade (LOA; grade 0-2) and severe (SOA; grade 3 or 4) groups. Radiographic parameters evaluated were pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), PI-LL, thoracic kyphosis (TK), SVA, T1-pelvic angle (TPA), T10-L2, proximal femoral shaft angle (PFSA), and hip flexion (PT change-PFSA change). Changes in sit-stand parameters were compared between LOA and SOA groups. RESULTS:548 patients were included (LOA = 311; SOA = 237). After propensity score matching for age, body mass index, and PI, 183 LOA and 183 SOA patients were analyzed. Standing analysis demonstrated that SOA had higher SVA (31.1 vs. 21.7), lower TK (-36.2 vs. -41.1), and larger PFSA (9.1 vs. 7.4) (all p < .05). Sitting analysis demonstrated that SOA had higher PT (29.7 vs. 23.3), higher PI-LL (21.6 vs. 12.4), less LL (31.7 vs. 41.6), less TK (-33.2 vs. -38.6), and greater TPA (27.9 vs. 22.5) (all p < .05). SOA had less hip ROM from standing to sitting versus LOA (71.5 vs. 81.6) (p < .05). Therefore, SOA had more change in PT (15.2 vs. 7.3), PI-LL (20.6 vs. 13.7), LL (-21.4 vs. -13.1), and T10-L2 (-4.9 vs. -1.1) (all p < .001), allowing the femurs to change position despite reduced hip ROM. SOA had greater TPA reduction (15.1 vs. 9.6) and less PFSA change (86.7 vs. 88.8) compared with LOA (both p < .001). CONCLUSIONS:Spinopelvic compensatory mechanisms are adapted for reduced hip joint motion associated with hip OA in standing and sitting. LEVEL OF EVIDENCE:Level III.

MINI: 172 patients underwent a primary TLIF. Those receiving <250 total MME (44%) as an inpatient had a 3.73 (odds ratio) times smaller probability of requiring opioids at 6 month follow-up. Patients who received >500 total MME (27%) had a 4.84 times greater probability of requiring opioids at 6 month follow-up.

STUDY DESIGN/METHODS:Single institution retrospective clinical review. OBJECTIVE:To investigate the relationship between levels fused and clinical outcomes in patients undergoing open and minimally invasive surgical (MIS) lumbar fusion. SUMMARY OF BACKGROUND DATA/BACKGROUND:Minimally invasive spinal fusion aims to reduce the morbidity associated with conventional open surgery. As multilevel arthrodesis procedures are increasingly performed using MIS techniques, it is necessary to weigh the risks and benefits of multilevel MIS lumbar fusion as a function of fusion length. METHODS:Patients undergoing <4 level lumbar interbody fusion were stratified by surgical technique (MIS or open), and grouped by fusion length: 1-level, 2-levels, 3+ levels. Demographics, Charlson Comorbidity Index (CCI), surgical factors, and perioperative complication rates were compared between technique groups at different fusion lengths using means comparison tests. RESULTS:Included: 361 patients undergoing lumbar interbody fusion (88% transforaminal, 14% lateral; 41% MIS). Breakdown by fusion length: 63% 1-level, 22% 2-level, 15% 3+ level. Op-time did not differ between groups at 1-level (MIS: 233 min vs. Open: 227, P = 0.554), though MIS at 2-levels (332 min vs. 281) and 3+ levels (373 min vs. 323) were longer (P = 0.033 and P = 0.231, respectively). While complication rates were lower for MIS at 1-level (15% vs. 30%, P = 0.006) and 2-levels (13% vs. 27%, P = 0.147), at 3+ levels, complication rates were comparable (38% vs. 35%, P = 0.870). 3+ level MIS fusions had higher rates of ileus (13% vs. 0%, P = 0.008) and a trend of increased adverse pulmonary events (25% vs. 7%, P = 0.110). MIS was associated with less EBL at all lengths (all P < 0.01) and lower rates of anemia at 1-level (5% vs. 18%, P < 0.001) and 2-levels (7% vs. 16%, P = 0.193). At 3+ levels, however, anemia rates were similar between groups (13% vs. 15%, P = 0.877). CONCLUSION/CONCLUSIONS:MIS lumbar interbody fusions provided diminishing clinical returns for multilevel procedures. While MIS patients had lower rates of perioperative complications for 1- and 2-level fusions, 3+ level MIS fusions had comparable complication rates to open cases, and higher rates of adverse pulmonary and ileus events. LEVEL OF EVIDENCE/METHODS:3.