V-Y vertebral body osteotomy for the treatment of fixed sagittal plane spinal deformity.

BACKGROUND CONTEXT

Fixed sagittal plane imbalance (FSI) has traditionally been corrected by either opening or closing wedge osteotomies or vertebral column resections. These methods involve multiple vertebrae and have been associated with limited degrees of correction and/or neurovascular compromise.

PURPOSE

We describe a new V-Y vertebral osteotomy (VYO) that involves a single vertebra, allowing for correction of all three columns in a safer fashion.

STUDY DESIGN

A prospective assessment of the degree of correction pre- and post-VYO in a tertiary spinal center.

PATIENT SAMPLE

Ten consecutive patients presenting with sagittal plane imbalance were enrolled in this study.

OUTCOME MEASURES

Outcomes were assessed with pre- (preop) and postoperative (postop) outcome questionnaires (Oswestry Disability Index [ODI] and Scoliosis Research Society-24) and radiography.

METHODS

Ten patients underwent VYO at L3 with varying levels of instrumentation. The procedure involves a V-shaped osteotomy in the sagittal plane, sparing the anterior 50% of the body, the apex of which is then converted to a Y shape, and the osteotomy closed.

RESULTS

Patients were followed for a mean of 36 months (24-48 months). The procedure led to significant improvements in sagittal balance, lumbar lordosis, thoracic kyphosis, coronal balance, sacral inclination, and pelvic incidence. The average degree of correction achieved was 44.58°±6.19° (mean±standard deviation). The mean blood loss was 1,287±350 mL and the operative time was 220±24 minutes. The mean preop ODI was 72% (range 58%-85%) and postop ODI averaged 22% (range 10%-30%). The mean preop SRS-24 score was 30.1 and postop was 101.

CONCLUSIONS

The VYO provides a safe correction of up to 45° at a single osteotomy site in FSI patients. It involves an isolated posterior approach and is recommended for corrections below the region of the conus.