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Study Design: Comparative cohort study. Objective: Factors that influence the lower instrumented vertebra (LIV) selection in adult cervical deformity (ACD) are less reported, and outcomes in the cervicothoracic junction (CTJ) and proximal thoracic (PT) spine are unclear. Methods: A prospective ACD database was analyzed using the following inclusion criteria: LIV between C7 and T5, upper instrumented vertebra at C2, and at least a 1-year follow-up. Patients were divided into CTJ (LIV C7-T2) and PT groups (LIV T3-T5) based on LIV levels. Demographics, operative details, radiographic parameters, and the health-related quality of life (HRQOL) scores were compared. Results: Forty-six patients were included (mean age, 62 years), with 22 and 24 patients in the CTJ and PT groups, respectively. Demographics and surgical parameters were comparable between the groups. The PT group had a significantly higher preoperative C2-C7 sagittal vertical axis (cSVA) (46.9 mm vs 32.6 mm, P = 0.002) and T1 slope minus cervical lordosis (45.9° vs 36.0°, P = 0.042) than the CTJ group and was more likely treated with pedicle-subtraction osteotomy (33.3% vs 0%, P = 0.004). The PT group had a larger correction of cSVA (−7.7 vs 0.7 mm, P = 0.037) and reciprocal change of increased T4-T12 kyphosis (8.6° vs 0.0°, P = 0.001). Complications and reoperations were comparable. The HRQOL scores were not different preoperatively and at 1-year follow-up. Conclusions: The selection of PT LIV in cervical deformities was more common in patients with larger baseline deformities, who were more likely to undergo pedicle-subtraction osteotomy. Despite this, the complications and HRQOL outcomes were comparable at 1-year follow-up.

Study Design: Retrospective cohort study. Objective: To investigate correlations between preoperative supine imaging and postoperative alignment. Methods: A retrospective review was conducted of a single-institution database of patients with adult spinal deformity (ASD). Patients were stratified by fusion location in the lumbar or thoracic spine. Outcomes of interest were postoperative lumbar lordosis (LL) and thoracic kyphosis (TK). Sagittal alignment parameters were compared and correlation analyses were performed. Multilinear stepwise regression was conducted to identify independent predictors of postoperative LL or TK. Regression analyses were repeated within the lumbar and thoracic fusion cohorts. Results: A total of 99 patients were included (mean age 63.2 years, 83.1% female, mean body mass index 27.3 kg/m2). Scoliosis Research Society classification demonstrated moderate to severe sagittal and/or coronal deformity (pelvic tile modifier, 18.2% ++; sagittal vertical axis, 27.3% ++, pelvic incidence minus lumbar lordosis mismatch, 29.3% ++, SRS type, 29.3% N type curve and 68.7% L or D type curve). A total of 73 patients (73.7%) underwent lumbar fusion and 50 (50.5%) underwent thoracic fusion. Correlation analyses demonstrated a significant association between pre- and postoperative LL and TK. Multilinear regression demonstrated that LL supine and pelvic incidence were significant predictors of postoperative LL ( r2 = 0.568, P < .001). LL supine, TK supine, and age were significant predictors of postoperative TK ( r2 = 0.490, P < .001). Conclusion: Preoperative supine films are superior to standing in predicting postoperative alignment at 1-year follow-up. Anticipation of undesired alignment changes through supine imaging may be useful in mitigating the risk of iatrogenic malalignment.

Study Design: Retrospective single-center study. Objective: Investigate the effect of posterior instrumentation on the relationship between lordosis and kyphosis. Methods: Surgically treated patients with a minimum of 6 months of follow-up were analyzed. Asymptomatic volunteers served to show the normal anatomical relationship between thoracic and lumbar curves. Patients were stratified based on postoperative instrumentation: “Thoracic Fusion” = complete fusion of thoracic spine; “Lumbar Fusion” = complete fusion of lumbar spine; and “Complete Fusion” = fusion from sacrum to at least T5. Bivariate correlations and regression analysis were used to evaluate the relationship between change in thoracic kyphosis (ΔTK) and change in spinopelvic mismatch (ΔPI-LL; pelvic incidence-lumbar lordosis) before and after fusion. Analyses were repeated in “Lumbar Fusion” patients with flexible preoperative thoracic spines. Results: For asymptomatic volunteers, the natural anatomical relationship between TK and LL was found to be TK = 41% of LL ( r = 0.425, P < .001). A total of 153 of 167 adult spinal deformity patients were included (62 years old, 26.7 kg/m2, 78% female). Mean follow-up was 11.5 ± 6.8 months. “Thoracic Fusion” group showed no alteration in the natural relationship between TK and LL (ΔTK = 39% ΔPI-LL), whereas “Lumbar Fusion” group had a reduction in reciprocal change (ΔTK = 34% ΔPI-LL) although a subanalysis of patients in the “Lumbar Fusion” group with flexible thoracic spines showed a marked compensation in reciprocal change with (ΔTK = 58% ΔPI-LL). Conclusion: The relationship between ΔTK and ΔPI-LL is dependent on level instrumented. “Thoracic Fusion” drives change in LL while this relationship is affected by TK’s natural stiffness in “Lumbar Fusion” patients.

Study Design: Retrospective cohort study. Objective: To compare the outcomes of patients with adult spinal deformity (ASD) following spinal fusion with the lowest instrumented vertebra (LIV) at L4/L5 versus S1/ilium. Methods: A multicenter ASD database was evaluated. Patients were categorized into 2 groups based on LIV levels—groups L (fusion to L4/L5) and S (fusion to S1/ilium). Both groups were propensity matched by age and preoperative radiographic alignments. Patient demographics, operative details, radiographic parameters, revision rates, and health-related quality of life (HRQOL) scores were compared. Results: Overall, 349 patients had complete data, with a mean follow-up of 46 months. Patients in group S (n = 311) were older and had larger sagittal and coronal plane deformities than those in group L (n = 38). After matching, 28 patients were allocated to each group with similar demographic, radiographic, and clinical parameters. Sagittal alignment restoration at postoperative week 6 was significantly better in group S than in group L, but it was similar in both groups at the 2-year follow-up. Fusion to S1/ilium involved a longer operating time, higher PJK rates, and greater PJK angles than that to L4/L5. There were no significant differences in the complication and revision rates between the groups. Both groups showed significant improvements in HRQOL scores. Conclusions: Fusion to S1/ilium had better sagittal alignment restoration at postoperative week 6 and involved higher PJK rates and greater PJK angles than that to L4/L5. The clinical outcomes and rates of revision surgery and complications were similar between the groups.

OBJECTIVE Recombinant human bone morphogenetic protein–2 (rhBMP-2) has been shown to increase fusion rates; however, cost, limited FDA approval, and possible complications impact its use. Decisions regarding rhBMP-2 use and changes over time have not been well defined. In this study, the authors aimed to assess changes in rhBMP-2 use for adult spinal deformity (ASD) surgery over the past decade. METHODS A retrospective review of the International Spine Study Group prospective multicenter database was performed to identify ASD patients treated surgically from 2008 to 2018. For assessment of rhBMP-2 use over time, 3 periods were created: 2008–2011, 2012–2015, and 2016–2018. RESULTS Of the patients identified, 1180 met inclusion criteria, with a mean age 60 years and 30% of patients requiring revision surgery; rhBMP-2 was used in 73.9% of patients overall. The mean rhBMP-2 dose per patient was 23.6 mg. Patients receiving rhBMP-2 were older (61 vs 58 years, p < 0.001) and had more comorbidities (Charlson Comorbidity Index 1.9 vs 1.4, p < 0.001), a higher rate of the Scoliosis Research Society–Schwab pelvic tilt modifier (> 0; 68% vs 62%, p = 0.026), a greater deformity correction (change in pelvic incidence minus lumbar lordosis 15° vs 12°, p = 0.01), and more levels fused (8.9 vs 7.9, p = 0.003). Over the 3 time periods, the overall rate of rhBMP-2 use increased and then stabilized (62.5% vs 79% vs 77%). Stratified analysis showed that after an overall increase in rhBMP-2 use, only patients who were younger than 50 years, those who were smokers, those who received a three-column osteotomy (3CO), and patients who underwent revision sustained an increased rate of rhBMP-2 use between the later two periods. No similar increases were noted for older patients, nonsmokers, primary surgery patients, and patients without a 3CO. The total rhBMP-2 dose decreased over time (26.6 mg vs 24.8 mg vs 20.7 mg, p < 0.001). After matching patients by preoperative alignment, 215 patients were included, and a significantly lower rate of complications leading to revision surgery was observed within the 2012–2015 period compared with the 2008–2011 (21.4% vs 13.0%, p = 0.029) period, while rhBMP-2 was increasingly used (80.5% vs 66.0%, p = 0.001). There was a trend toward a lower rate of pseudarthrosis for patients in the 2012–2015 period, but this difference did not reach statistical significance (7% vs 4.2%, p = 0.283). CONCLUSIONS The authors found that rhBMP-2 was used in the majority of ASD patients and was more commonly used in those with greater deformity correction. Additionally, over the last 10 years, rhBMP-2 was increasingly used for ASD patients, but the dose has decreased.