Spinal instrumentation without fusion for progressive scoliosis in young children.

Between 1973 and 1993, a heterogeneous group of 67 children with progressive scoliosis entered a program of incremental-distraction spinal instrumentation without fusion supplemented by full-time external orthotic support. Over the course of treatment, curve magnitude improved from an average of 67 degrees at initial instrumentation to 47 degrees at definitive fusion. For all patients, curve response tended to decline with consecutive procedures. The measured growth of the instrumented but unfused spinal segments averaged 3.1 cm over a mean treatment period of 3.1 years. The results of our study suggest that spinal instrumentation without fusion can control progressive scoliosis in a majority of children while allowing normalized growth of instrumented spinal segments. The mean duration of treatment and ultimate gain in spinal length are constrained by progressive structural changes that alter curve response to incremental distraction. Despite these limitations, spinal instrumentation without fusion may provide a reasonable management alternative when individualized among these difficult patients.