Temporary internal distraction as an aid to correction of severe scoliosis

Background: Halo traction is a well-recognized adjunct for correcting severe complex rigid scoliotic curves, but it is associated with complications and is contraindicated in the presence of fixed cervical instability, kyphosis, or stenosis. In addition, halo traction often requires prolonged hospital stays and is not welcomed by all families. These limitations led to consideration of temporary internal distraction as an alternative. Methods: We retrospectively reviewed the records of children in whom severe scoliosis had been treated with temporary internal distraction. Our goals were to (1) assess whether the use of temporary internal distraction can aid in the correction of severe scoliosis and (2) identify complications associated with temporary internal distraction and compare them with those associated with halo traction. The mean preoperative curve was 104°. All patients underwent initial posterior release of the rigid portion of the spine (with six also having anterior release) and placement of spinal instrumentation under distraction during spinal cord monitoring. Of the ten patients, four had one distraction procedure (i.e., the initial surgery [or first distraction] followed by definitive fusion and the remaining six had two distraction procedures (i.e., the initial surgery [or first distraction] followed by the second distraction) followed by definitive fusion. After distraction, all patients underwent posterior spinal fusion with definitive dual-rod fixation. The amount of correction was determined by measuring the curve on plain radiographs made preoperatively, after each internal distraction procedure, after definitive fusion, and at the time of final follow-up. Results: Curve correction after use of internal distraction, and before definitive fusion, averaged 53% (from 104° to 49°) (range, 39% [from 70° to 43°] to 79% [from 70° to 15°]). This method facilitated safe, gradual deformity correction in all ten patients. The mean time between the initial procedure and the definitive fusion was 2.4 weeks. The mean final curve correction was 80% (from 104° to 20°) (range, 73% [from 131° to 35°] to 91% [from 110° to 10°]). No neurologic deficits or infections resulted. Conclusions: Temporary internal distraction is a viable alternative approach to maximizing curve correction in patients undergoing spinal fusion for severe scoliosis. Level of Evidence: Therapeutic Level IV.