Single level of posterior closing-wedge and anterior extension lumbar osteotomy for ankylosing spondylitis.

From 1993 to 1997 we treated 11 consecutive patients who had progressive spinal kyphosis due to ankylosing spondylitis by a posterior closing-wedge and anterior extension lumbar osteotomy and interspinous process wiring. The average correction was 44o (37-57) with a mean loss of correction after operation of 11.2o (6-20). The average operating time was 130 minutes (80 to 180) and blood loss was 486 ml (400-700). The osteotomy corrected all patients sufficiently to allow them to see ahead and improve their posture. There were no complication of implant failure as well as nerve root injury.