Spino‐Pelvic Thresholds for Prevention of Proximal Junctional Kyphosis Following Combined Anterior Column Realignment and Short Posterior Spinal Fusion in Degenerative Lumbar Kyphosis

OBJECTIVE To analyze ideal indication for combined anterior column realignment (ACR) with short posterior spinal fusion (PSF) and posterior column osteotomy (PCO) for preventing proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower lumbar kyphosis and compensatory thoracolumbar lordosis. METHODS A retrospective study was conducted. This study included 27 ASD patients (average age of 66.6 years; one male and 26 females) with lower lumbar kyphosis and compensated thoracolumbar lordosis who underwent short PSF with PCO following ACR from 2006 to 2010. The minimum follow-up period was 5 years. The patients were divided into two groups based on the sagittal vertical axis (SVA) of the last follow-up radiographs, and a comparative analysis was performed evaluating spino-pelvic parameters and clinical outcomes including the Oswestry Disability Index (ODI), Visual Analog Scale (VAS), and complications. RESULTS The mean follow-up time of included patients was 109.7 months, and the mean number of fused segments was 3.7. The uppermost instrumented vertebra was L2 in 18 patients or L3 in nine patients, and lowermost instrumented vertebra was sacrum in all patients. The mean lumbar lordosis (LL) values in the optimal SVA and suboptimal SVA groups were 4.4° and 4.2° preoperatively (P = 0.639), -48.1° and -35° postoperatively (P = 0.007), and -45.2° and -20.7° at the last follow-up (P