Kyphectomy in patients with myelomeningocele treated with pedicle screw–only constructs: case reports and review

Abstract

Significant lumbar kyphosis is frequently observed in patients with myelomeningocele and has been associated with increasing functional impairment, decreased abdominal volume, respiratory impairment, discomfort, and skin ulcerations overlying the prominent gibbus. Treatment of severe kyphotic deformities can include kyphectomy, with or without ligation of the thecal sac, with posterior spinal fixation. However, most series have reported a high rate of morbidity and complications associated with surgical intervention for correction of kyphosis in patients with myelomeningocele. The authors describe a technique in which pedicle screw (PS)-only constructs are used without transection of the thecal sac to treat severe kyphosis successfully, with minimal morbidity. The authors retrospectively reviewed medical records and radiographic images in 2 patients with myelomeningoceles in whom kyphectomies had been performed at the authors' institution between January 2007 and July 2010. They also reviewed the existing literature for case reports or published series of patients with myelomeningocele treated with kyphectomies, to evaluate the outcomes. Both patients were male and had thoracic-level myelomeningoceles that had been repaired at birth, with associated paraplegia. Neither patient had any significant scoliotic deformity associated with the kyphosis, and both had fixation from T-9 to the ilium, which was performed using PS constructs, along with L1-2 kyphectomies. The patient in Case 1 was 20 years old and was treated for progressive kyphosis and an ulcerated nonhealing wound over the gibbus. The patient in Case 2 was 10 years old and was treated for progressive pain and functional impairment. The 2 patients had a mean correction of 63%, with a mean correction of kyphotic deformity from 136° to 51°. Neither patient developed any complication in the short term postoperatively, whereas published series have reported high complication rates, including wound infection, poor wound healing, CSF leakage, pseudarthrosis, and shunt malfunction. Severe kyphotic deformities in patients with myelomeningocele can be safely treated using PS-only constructs without ligation of the thecal sac. Further evaluation with a larger sample and longer follow-up are needed to detect any associated complications, such as proximal junctional kyphosis. Further evaluation may also validate whether PS-only constructs permit successful outcomes with a shorter construct and fewer instrumented levels.