Surgical treatment of severe angular kyphosis with myelopathy - Anterior and posterior approach with pedicle screw instrumentation

Abstract

Study Design. Retrospective study. Objective. To evaluate the outcomes of anterior decompression and fusion followed by posterior instrumented fusion using pedicle screws without intentional correction of severe angular kyphosis deformity with myelopathy. Summary of Background Data. Treatment of severe angular kyphosis with myelopathy is extremely difficult and dangerous. Although surgical circumferential spinal osteotomy via a single posterior approach has been reported in several studies, serious neurologic complications are a possible outcome. Materials and Methods. Among 51 patients surgically treated for angular kyphosis from 1988 to 2004, 16 patients ( follow- up period, 32 - 168 months; mean, 72 months) with severe ( > 70 degrees) angular kyphosis with progressive myelopathic symptoms underwent anterior decompression and fusion, followed by posterior pedicle screw instrumentation and bone graft without attempted correction of the deformity. Radiologic assessment, clinical findings including pain and daily activity scores, and neurologic status using the modified Frankel grade were analyzed before surgery and at the last follow- up. Results. Curve progression or nonunion did not occur in any of the cases. The mean pain and daily activity score were 3.1 and 2.3 before surgery and 4.7 and 4.2 after surgery, respectively. The modified Frankel grade indicated that every patient but one had improved neurologic function by one or more grades. Nine ( 75%) of 12 patients with ankle clonus, 10 ( 71%) of 14 patients with Babinski sign, and 6 ( 55%) of 11 patients with bowel and bladder dysfunction showed full improvement at the last follow-up. Postoperative complications included 1 screw pullout case and 2 infection cases which resolved without incidence. Conclusion. Anterior decompression and fusion followed by posterior pedicle screw instrumentation and fusion without correction effectively improved neurologic symptoms and halted progression of kyphotic deformity in cases of severe angular kyphosis with myelopathy.