Posterior Vertebral Column Resection (PVCR) in Fixed Lumbosacral Deformity

Fixed lumbosacral deformity has gross imbalance as well as progressive compensatory thoracolumbar deformity because of the absence of a mobile spine caudally. There is no consensus of the surgical treatment of fixed lumbosacral deformity. The fixed lumbosacral deformity can be managed by the posterior vertebral column resection (PVCR), which not only corrects the deformity but also restore the trunk balance by translation of spinal column.

Purpose: To report the results and its technique of posterior vertebral column resection (PVCR) in the fixed lumbosacral deformity.

Materials and Methods: Twenty two fixed lumbosacral deformity patients subjected to PVCR were retrospectively reviewed after a minimum follow-up of 2 years (range: 2~6.3 years). All patients had their offending vertebrae below L4. Etiological diagnoses were congenital kyphoscoliosis in 7, post-traumatic kyphosis in 2, and postinfectious kyphosis in 13. The average age at the operation was 37 years (range: 2.5 ~61 years) with a 7:15 male:female ratio. The indication of posterior vertebral column resection was fixed lumbosacral deformities that could not be brought to a reasonable balance on traction or forced side bending. Preoperatively 10 patients (45 %) presented neurologic compromise, and 17 patients(77 %) presented intractable back pain. The surgical technique consisted of segmental pedicle screw fixation, decompression of neural structure and resection of the vertebral column at the apex of the deformity via the posterior route, followed by deformity correction and global fusion. During the resection, all the nerve roots in both sides were kept intact.

Results: The numbers of vertebrae removed were 2.2 in average, and 48 in total. The average fusion extent was 4.5 vertebrae (range: 2~8 vertebrae). The anterior column reconstruction was carried out with autogenous bone graft in all patients and additional insertion of titanium mesh in 11. The distal anchor went down to L5 in 3 patients, S1 in 12, and S2 in 7. Preoperative scoliosis of 40±12º was corrected to 16±9º (60 % correction) at most recent follow-up, and preoperative kyphosis of 35±26º was corrected to -6±11º(41º correction). The compensatory coronal curve of 24º was spontaneously corrected to 11º at most recent follow-up. The preoperative thoracic lordosis of -17º was corrected to 3º at most recent follow-up, and the preoperative lumbar kyphosis of 21º was corrected to -15º. Preoperative coronal imbalance of 1.7 cm was improved to 0.8 cm at most recent follow-up, and preoperative sagittal imbalance of 9.6 cm was improved to 4.8 cm. Mean operation time was 288 minutes with a blood loss of 2922ml. The preoperative neurologic compromise was improved in all patients and pain was reduced in 15 patients. The complications were encountered in 5 patients: 2 transient neurology that were improved without a sequel within 6 months, 1 pseudarthrosis, and 2 compression fractures at proximal adjacent vertebra.

Conclusions: Posterior vertebral column resection is an effective procedure for the management of fixed lumbosacral deformity. It gives not only satisfactory correction but also improved functional outcomes. However, it is a technically demanding and exhausting procedure with possible risks for complications.