Prevention of the crankshaft phenomenon.

Factors favoring development of the crankshaft phenomenon after posterior spinal fusion include immaturity and large residual deformity. Eight patients at high risk to develop the crankshaft phenomenon underwent periapical anterior growth arrest and fusion before posterior instrumentation and fusion. With follow-up to skeletal maturity, 0% developed crankshaft phenomenon. Anterior growth arrest and fusion before a posterior procedure is recommended in scoliosis patients at high risk to develop the crankshaft phenomenon.