Long-segment posterior instrumentation and fusion with freeze-dried allograft in congenital scoliosis.

Abstract

The aim of this study was to evaluate the effectiveness of long-segment posterior instrumentation and allograft application in obtaining fusion in congenital scoliosis. Twenty-one patients with congenital scoliosis who were treated with long-segment posterior instrumentation (>6 levels) and freeze-dried allograft and followed up for more than 24 months were reviewed. Six patients were excluded from the study due to anterior procedures. Fifteen patients with congenital scoliosis (13 females, 2 males; mean age: 12.2 ± 3 years, range: 7-17 years) were retrospectively reviewed. Mean follow-up time was 30.9 ± 9.4 (range: 24 to 48) months. Six patients had laminectomy either due to previous posterior surgeries or to address intraspinal pathologies during the posterior fusion procedure. Preoperative, postoperative and final follow-up anteroposterior and lateral spine X-rays were reviewed. Fusion was graded according to the classification reported by Bridwell et al. Two patients were graded as 'no fusion' (pseudarthrosis), four patients as 'probably fused', and nine patients as 'definitely fused'. The major curve was corrected from an average of 68 ± 18.6 to 39.3 ± 12.2 degrees (p<0.001). Mean correction lost in the major curve was an average of 4.5 ± 5.2 degrees in the latest follow-up. There was significant correction in the compensatory curve (preoperative 37.9 ± 13.2 degrees, postoperative 20.2 ± 6.6 degrees; p=0.001). Preoperative and postoperative global thoracic kyphosis were 39.5 ± 13.3 and 32.3 ± 7.9 degrees, respectively (p=0.018). Preoperative and postoperative global lumbar lordosis was 36.3 ± 7.4 and 36.1 ± 8.9 degrees, respectively (p=0.883). Successful fusion was detected in %86.7 of patients in the final follow-up. The usage of allograft alone to achieve fusion increases the rates of pseudarthrosis while additional anterior procedure decreases the pseudarthrosis rate in patients with congenital scoliosis that require long-segment posterior instrumentation. Further studies should be performed to assess the efficacy of the usage of polysegment pedicle screw instrumentation.