Closing wedge osteotomy versus opening wedge osteotomy in ankylosing spondylitis with thoracolumbar kyphotic deformity.

STUDY DESIGN

Retrospective.

OBJECTIVES

To compare lumbar posterior opening wedge osteotomy (OWO) and closing wedge osteotomy (CWO) in patients with thoracolumbar kyphotic deformity attributable to ankylosing spondylitis.

SUMMARY OF BACKGROUND DATA

OWO and CWO have been used to correct ankylosing spondylitis-related kyphotic deformity, but the ideal surgical procedure remains controversial.

METHODS

Sixty-six patients underwent OWO, and 51 underwent CWO (102 male, 15 female; mean age, 34.8 years; age range, 17-55 years). Radiographic results, complications, and patient satisfaction were analyzed over a mean follow-up of 3.6 years (range, 2.1-5.3 years)

RESULTS

For OWO and CWO, mean operative times were 183 and 218 minutes, and mean blood losses were 1101 and 1915 mL, respectively. Lumbar lordosis increased by 37 degrees with OWO versus 36 degrees with CWO group, as shown on final radiographs. Sagittal imbalance improved 80 and 77 mm with OWO and CWO, respectively. Complications included delayed union in three patients and a broken rod at the osteotomy site in the OWO group. Six transient neurologic deficits occurred overall. No mortality or major complications occurred. Five patients developed junctional kyphosis (two undergoing OWO, three undergoing CWO), and all required repeat operation. Satisfactory clinical outcomes were achieved in both groups.

CONCLUSION

Both OWO and CWO were safe and enabled substantial correction, with good clinical results. CWO resulted in a significantly longer operative time and more bleeding but offered fewer instances of paralytic ileus or delayed union with a broken rod.