Analysis of surgical outcomes and complications following SRS-Schwab grade 6 osteotomy in angular hyperkyphotic deformity: 90 cases with a minimum 2-year follow-up.

PURPOSE: To report the surgical outcomes and complications of the Scoliosis Research Society (SRS)-Schwab grade 6 osteotomy in patients with severe thoracic angular kyphosis (TAK), and to investigate the risk factors of major surgical complications.

METHODS

All patients undergoing SRS-Schwab grade 6 osteotomy for TAK between May 2010 and January 2022 were enrolled. Radiographic changes after surgery were analyzed. Back pain and neurological function were evaluated via Visual analogue scale (VAS) and Japanese Orthopedic Association (JOA) score. Overall complications were classified for each patient using the ISSG-AO Multi-Domain Spinal Deformity Complication Classification System. Univariate and multivariable logistic regression were used to identify the independent risk factors of major surgical complications.

RESULTS

Ninety cases of thoracic tuberculosis complicated with severe angular kyphosis undergoing SRS-Schwab grade 6 osteotomy were analyzed. The mean operating time was 399.8 min, and the mean blood loss was 1627.8 ml. The average segmental kyphosis was significantly corrected from 95.3 ± 25.2° preoperatively to 34.8 ± 16.0° postoperatively. The VAS was statistically decreased from 3.4 ± 2.8 to 1.0 ± 0.9. The JOA score was significantly improved from 6.7 ± 2.6 to 9.4 ± 2.0. The incidences of medical and surgical complication were 23.3% and 62.2% respectively. The most common complications were neurological deficit (36.7%), dural tear (21.1%), and pleural effusion (10%), and 13 patients (14.4%) required a revision. Kyphotic apex at upper-middle thoracic spine (OR = 4.59, 95% CI = 1.43-14.79; p = 0.011) and sagittal-deformity angular ratio (DAR) ≥ 25 (OR = 9.28, 95% CI = 1.80-47.92; p = 0.008) were independent risk factors for major surgical complications.

CONCLUSIONS

Though technical difficulty and high complication rate, SRS-Schwab Grade 6 osteotomy offers a one stage solution with enormous potential to correct rigid kyphosis and improve neurological status.