Segmental pedicle screws instrumentation and fusion to L5 for spinal deformity secondary to Duchenne muscular dystrophy: Results with a minimum of 2 years follow-up

Background: Traditional treatment recommendations in the surgical treatment of scoliosis in Duchenne muscular dystrophy have included instrumentation and fusion to the sacrum/pelvis to correct pelvic obliquity and to restore the sitting balance of the trunk. However, caudal extent of instrumentation and fusion has remained a matter of considerable debate. This study was performed to determine the efficacy and safety of stopping segmental pedicle screw constructs at L5 in the surgical treatment of scoliosis in Duchenne muscular dystrophy (DMD), with mild pelvic obliquity (<15°). Materials and methods: From May 2005 to June 2007, a total of 22 consecutive patients underwent posterior spinal fusion and segmental pedicle screw instrumentation only to L5 for scoliosis secondary to DMD. A minimum 2-year follow-up was required for inclusion in this study. Assessment was performed clinically and with radiologic measurements. Radiologic measurements included the Cobb angles of the curves in the coronal plane, thoracic kyphosis and lumbar lordosis in the sagittal plane, and pelvic obliquity. The operating time, blood loss, and complications were evaluated. Results: Twenty patients, aged 11-17, were enrolled. The average follow-up period was 35 months. Preoperative coronal curves averaged 70° (range: 51-85°), with a postoperative mean of 15° (range: 8-25°) and 17° (range: 9-27°) at the last follow-up. Pelvic obliquity improved from 13° (range: 7-15°) preoperatively to 5° (range: 3-8°) postoperatively and 6° (range: 3-9°) at the last follow-up. Good sagittal plane alignment was recreated and maintained. No loss of correction of scoliosis and pelvic obliquity was noted. The mean operating time was 271 min (range: 232-308 min). The mean intraoperative blood loss was 890 ml (range: 660-1260 ml). The mean total blood loss was 2100 ml (range: 1250-2880 ml).There was no major complication. Conclusion: Segmental pedicle screw instrumentation and fusion to L5 is effective and safe in patients with scoliosis secondary to DMD without significant pelvic obliquity initially and long term, obviating the need for fixation to the sacrum/pelvis. There was no major complication.