The efficacy and complications of posterior hemivertebra resection.

There have been several reports on hemivertebra resection via a posterior-only procedure. However, the number of reported cases is small, and various types of instrumentation have been used. In our study, we retrospectively investigated 56 consecutive cases of congenital scoliosis that were treated by posterior hemivertebra resection with transpedicular instrumentation. Radiographs were reviewed to determine the type and location of the hemivertebra, the coronal curve magnitude and the sagittal alignment pre-operatively, post-operatively and at the latest follow-up. Radiographs were also used to assess implant failure and inter-body fusion. Surgical reports and patient charts were reviewed to record any peri-operative complications. Fifty-eight posterior hemivertebrae resections from 56 patients aged 1.5-17 years with fully segmented non-incarcerated hemivertebra were evaluated. The average age at surgery was 9.9 years (1.5-17 years). The average follow-up was 32.9 months (24-58 months). The mean fusion level was 5.0 segments (2-11 segments). There was a mean improvement of 72.9% in the segmental scoliosis, from 42.4° before surgery to 12.3° at the time of the latest follow-up, and there was a mean improvement of 70% in segmental kyphosis from 42.0° to 14.5° over the same time period. The thoracic kyphosis (T5-T12) averaged 10.8° before surgery and 23.9° at the latest follow-up. The lumbar lordosis (L1-S1) averaged -52.8° before surgery and -51.6° at the latest follow-up. Two cases with neurological claudications had complete recovery immediately after the surgery. There was one case of delayed wound healing, two fractures of the pedicle at the instrumented level, two rod breakages and one proximal junction kyphosis that required revision. There were no neurological complications. Radiolucent gaps were found in the residual space after resection on the lateral view in five cases, without any sign of implant failure or correction loss. Our results show that one-stage posterior hemivertebra resection with transpedicular instrumentation can achieve excellent correction, 360° decompression and short fusion without neurological complications. Pedicle cutting still remains a challenge in younger children when using bisegmental instrumentation. In addition, the radiolucent gaps in the residual space require further investigation.