Kyphectomy in myelomeningocele with a modified Dunn-McCarthy technique followed by an anterior inlayed strut graft

Rigid congenital kyphosis in myelomeningocele is associated with an important morbidity with skin breakdown, recurrent infection, and decreased function. Kyphectomy is the classic treatment to restore spinal alignment; however, surgery is associated with an important morbidity and long-term correction is uncertain. The authors retrospectively reviewed 9 patients with a mean age of 8.8 years who underwent a two stage surgical procedure: first a posterior kyphectomy with a modified Dunn-McCarthy fixation consisting of lumbar pedicle screws and long S-shape rods buttressing the anterior sacrum. Then a second stage done several weeks later consisting of a thoraco-abdominal approach to the spine with an inlay strut graft classically from T10–S1. The mean follow-up was 34 months (range 1–5 years). The kyphosis was corrected from a mean of 110° of Cobb angle (range 70–130°) to 15° after surgery (45–0°). There was no instrumentation failure, no loss of correction and no pseudarthrosis. Complications consisted of one intra-operative cardiac arrest fortunately reversible, a wound necrosis, one deep venous thrombosis and one late aseptic bursitis on the posterior hardware. Congenital kyphosis in myelomeningocele can be treated successfully with an initial posterior approach correction and instrumentation followed by an anterior approach allowing for anterior inlay impacted structural graft. The authors believe that this technique improves biomechanical and biological fusion mass anteriorly and will prevent late instrumentation failure and loss of correction.