Michael S. Chang

Comparative analysis of clinical outcomes and complications in patients with degenerative scoliosis undergoing primary versus revision surgery.

Study Design. Retrospective cohort analysis of prospectively collected data. Objective. To compare clinical outcomes and postoperative complications in patients with lumbar degenerative scoliosis who underwent primary (P) versus revision (R) surgery. Summary of Background Data. Revision surgery for spinal deformity is technically challenging and may be associated with greater risks of complications and inferior clinical outcomes. There is a paucity of data in the literature comparing primary versus revision surgery in patients with degenerative scoliosis with respect to their clinical outcomes and complications. Methods. An analysis of 84 consecutive patients with degenerative scoliosis who underwent primary versus revision surgery between 2002 and 2010 with a minimum 2-year follow-up was performed. Results. There were 53 patients in the primary group and 31 in the revision group. The average number of previously operated levels in the revision group was 3.5 ± 2.6. Mean age at surgery, sex, and body mass index were similar between the 2 groups, as well as comorbidities and postoperative complication rates (P > 0.05). Although a greater preoperative coronal imbalance was noticed in the revision group (P: 2.5 cm vs. R: 4.8 cm, P = 0.022), the final radiographical measures were comparable between the 2 groups. At 2-year follow-up, Oswestry Disability Index and visual analogue scale scores improved significantly in both groups compared with preoperatively (P < 0.001). The improvement in scores of Oswestry Disability Index and visual analogue scale preoperatively to final follow-up was similar between the 2 groups (P > 0.05). Conclusion. Revision patients achieved the same radiographical and clinical outcomes as primary patients. The complication rates were similar between primary and revision patients. Revision patients benefit from surgery just as much as primary patients at 2-year follow-up. Level of Evidence: 3

Does Obesity Affect Surgical Outcomes in Degenerative Scoliosis

Study Design. Retrospective cohort analysis of prospectively collected data. Objective. To determine whether an association exists between body mass and surgical outcomes in patients with degenerative scoliosis after long instrumented spinal arthrodesis (≥ 4 discs). Summary of Background Data. Obesity is thought to be associated with increased surgical complications and inferior clinical outcomes in adults. There are no studies analyzing the effect of obesity on surgical outcomes in patients with degenerative scoliosis after long instrumented spinal arthrodesis. Methods. Eighty-four consecutive patients with degenerative scoliosis (69 females and 15 males; mean age, 68.6 ± 8.0 yr) with a minimum follow-up of 2 years were included in this study. Patients were divided into 3 groups according to body mass index (BMI): obese (BMI ≥ 30 kg/m2, n = 19), overweight (BMI = 25–29.9 kg/m2, n = 35), and normal weight (BMI < 25 kg/m2, n = 30). Radiographical measures, Oswestry Disability Index, visual analogue scale score, as well as comorbidities and complications were reviewed and analyzed for all patients preoperativelyand at 1- and 2-year follow-ups. Results. Compared with the normal weight group, no significant differences in surgical methods, comorbidities, complication rates, curve correction, or radiographical measures were found in the obese and overweight groups, except for a greater preoperative lumbar lordosis in the overweight group (−40.3° ± 13.8° vs. −26.0° ± 18.9°, P < 0.05). At 2-year follow-up, Oswestry Disability Index and visual analogue scalescores improved significantly in all groups compared with preoperatively (P < 0.01). The changes of Oswestry Disability Index and visual analogue scalescores from preoperatively to final follow-up were similar in the 3 groups (P > 0.05). Conclusion. Obesity did not affect the amount of deformity correction and did not increase comorbidities and postoperative complication rates. Overweight patients had a greater lumbar lordosis before surgery than normal weight patients. Obese and overweight patients benefited from surgery just as much as normal weight patients at 2-year follow-up. Level of Evidence: 4

Revision spinal fusion in patients older than 75: is it worth the risks?

Study Design. Retrospective clinical study of a prospective database. Objective. This study aims to determine whether revision spinal fusion surgery is worthwhile in patients older than 75 from a risk-benefit perspective. Summary of Background Data. The benefits of spinal fusion in patients older than 65 is well documented. However, the clinical benefit to patients older than 75 of revision surgery, which often yields worse outcomes with higher complication rates, is uncertain. Methods. Ninety-nine consecutive patients older than 75 with minimum 2-year follow-up underwent spinal fusion as either a primary (n = 58) or revision (n = 41) operation. Diagnoses were spondylolisthesis (n = 43), scoliosis (n = 28), kyphosis (n = 5), and other degenerative spinal disorders (n = 26). Outcomes were obtained prospectively by visual analogue scale (VAS) and Oswestry Disability Index (ODI) at preoperative, 1-year, 2-year, and latest follow-up. Results. Revision patients had significantly worse scores compared with primary patients at all time intervals, for both VAS (preoperative: 6.4 vs. 5.8, 1 yr: 3.6 vs. 2.4, 2 yr: 4.7 vs. 2.5) and ODI (preoperative: 52.2 vs. 44.1, 1 yr: 37.3 vs. 25.6, 2 yr: 47.0 vs. 25.0). Both groups improved significantly at 1 year postoperatively. At 2 years, the results of revision surgery deteriorated (&Dgr;VAS: −1.7, &Dgr;ODI: −5.2), whereas the benefits of primary procedures were maintained (&Dgr;VAS: −3.3, &Dgr;ODI: −19.1). Complications were generally greater in the revision group and included revision surgery (8[19.5%] vs. 7[12.1%]), nonunion (2[4.9%] vs. 3[5.2%]), adjacent level fracture (4[9.8%] vs. 6[10.3%]), infection (6[14.7%] vs. 2[3.4%]), foot drop (0[0.0%] vs. 4[6.9%]), imbalance (4[9.8%] vs. 1[1.7%]), pulmonary failure (1[2.4%] vs. 1[1.7%]), and death (0[0.0%] vs. 1[1.7%]). Conclusion. Despite having worse initial ODI and VAS scores, revision patients older than 75 initially benefit as much as patients older than 75 undergoing primary operations. However, at 2 years, revision patients do not have a sustained benefit despite a higher complication rate. Level of Evidence: 4

Associations between Body Mass and Revision Surgical Outcomes in Adult Scoliosis.

Study Design:Retrospective cohort study. Objective:To determine whether an association exists between high body mass index (BMI>25 kg/m2) and surgical outcomes in revision adult scoliosis patients. Summary of Background Data:Obesity is thought to be associated with increased surgical complications and inferior clinical outcomes in adults. There are no studies analyzing the effect of obesity on surgical outcomes in revision patients for adult scoliosis. Methods:Forty-five consecutive revision adult scoliosis patients (35 women and 10 men; mean age, 62.7±9.3 y) with a minimum follow-up of 2 years were included in this study. Patients were divided into 2 groups according to BMI: overweight (BMI≥25 kg/m2, n=27) and nonoverweight (<25 kg/m2, n=18). Radiographic measures, Oswestry Disability Index (ODI), Visual Analog Scale (VAS), as well as comorbidities and complications were reviewed and compared at preoperative and 2-year follow-up. Results:No significant differences in surgical methods, complication rates, or radiographic measures were found between the 2 groups except for the greater preoperative and final follow-up thoracic kyphosis in the overweight group (P<0.05). A higher comorbidity rate of circulatory disorders (33.3% vs. 0%, P=0.018) and diabetes (25.9% vs. 0%, P=0.053) was observed in the overweight group, as well as a higher preoperative VAS score (7.1±1.7 vs. 5.2±2.9, P=0.031). At 2-year follow-up, VAS and ODI improvements for both groups showed significant and similar improvement from preoperative (P<0.01). Conclusions:Overweight revision adult scoliosis patients had higher thoracic kyphosis and more significant preoperative pain compared with normal-weight individuals. Overweight patients also had significantly higher rates of medical comorbidities. However, BMI did not affect the functional outcome of surgical correction or perioperative complication rates. Overweight patients benefited from surgery just as much as nonoverweight patients at 2-year follow-up.