Posterior vertebral column resection for correction of rigid spinal deformity curves greater than 100°
Authors: Xie Jingming , Wang Yingsong , Zhao Zhi , Zhang Ying , Si Yongyu , Li Tao , Yang Zhendong , Liu Luping 
Published: October 2012

Object
The surgical treatment of severe and rigid spinal deformities poses difficulties and dangers. In this article, the authors summarize their surgical techniques and evaluate patient outcomes after performing posterior vertebral column resection (PVCR) for the correction of spinal deformities with curves greater than 100°, and investigate the crucial points to ensure neurological safety during this challenging procedure.

Methods
The authors retrospectively reviewed their experience with 28 patients with extremely severe (Cobb angles in the coronal or sagittal plane > 100°) and rigid thoracic or thoracolumbar spine deformities who underwent PVCR. The average patient age was 20.2 years and all patients underwent a minimum follow-up of 24 months (range 24–60 months). Patients were divided into groups according to their morphological classification as follows: kyphosis alone (Group A, 6 patients with a mean Cobb angle of 109.0° [range 105°–120°]); kyphoscoliosis with coronal plane curves notably greater than sagittal plane curves (Group B, 14 patients with mean scoliotic curves of 116.6° [range 102°–170°] and kyphotic curves of 77.7° [range 42°–160°]); and kyphoscoliosis with sagittal curves notably greater than coronal plane curves (Group C, 8 patients with a mean coronal curve of 85.4° [range 65°–110°] and a mean sagittal curve of 117.6° [range 102°–155°]).

Results
A total of 36 vertebrae were removed in 28 patients who had a severe rigid spinal deformity, and the mean fusion extent was 13.3 vertebrae (range 7–17 vertebrae). The mean operating time was 620 minutes (range 320–920 minutes) with an average operative blood loss of 6,680 ml (range 3,000–24,000 ml). The overall final correction rate of scoliosis was 59.0%, and average postoperative kyphotic Cobb angles ranged from 30.4° to 95.9°. In Group A the mean preoperative sagittal angle of 109.0° was corrected to a mean postoperative angle of 32.0°. In the Group B kyphoscoliotic patients, the correction rate in the coronal plane was 58.6%; the Cobb angle in the sagittal plane was corrected from a mean of 77.7° preoperatively to 25.1° postoperatively; in Group C, the correction rate in the coronal plane was 58.5%, and the mean sagittal angle was reduced from a mean of 117.6° preoperatively to 39.0°. Of the 28 patients who underwent PVCR, 46 complications were observed in 18 patients intra- and postoperatively. There were 5 neurological complications including 1 case of late-onset paralysis and 4 cases of thoracic nerve root pain, all of which resolved during the early follow-up period. Nonneurological complications occurred more often in kyphoscoliotic patients (41 complications). The mean follow-up of all patients was 33.7 months (range 24–60 months).

Conclusions
Posterior vertebral column resection was effective in correcting severe rigid spinal deformity, although the procedure was technically demanding, exhaustingly lengthy, and was associated with a variety of complications. The PVCR technique created a space for spinal correction and spinal cord tension adjustment and the correction could be performed under direct inspection and by palpation of the tension in the spinal cord through the space. Therefore, in terms of the spinal cord, the deformity correction process involved in the PVCR procedure is relatively safe.