Nerve injury and limb lengthening after hip replacement: treatment by shortening.

Nineteen patients had a severe neurologic deficit and persistent dysesthetic pain after total hip replacement. During surgery their limbs had been lengthened by 1.3 to 4.1 cm. Patients with other reasons for nerve injury such as hematoma, dislocation, or direct operative trauma were excluded. Also excluded were patients whose lengthening was part of the operative plan to address previous shortening. None of the patients had neurologic deficits or dysesthetic pain preoperatively. Patients were offered revision hip surgery to shorten the limb. Seventeen patients proceeded to surgery. Two acetabular revisions, five modular femoral head exchanges, and 10 femoral component revisions were done. The average shortening was 1.5 cm (range, 0.5-3.6 cm). The trochanter was advanced in four patients and a constrained acetabular liner was used in four patients. Nine hips were stable without additional measures. There were no complications and nine patients had an excellent result. This was defined as elimination of their dysesthetic pain. Two patients had partial improvement and six patients had no improvement. Seven of 11 patients with motor deficits had improvement in strength with three making a full recovery. When painful neurologic symptoms accompany limb lengthening after total hip replacement, revision surgery may be helpful, although patients should be informed the rate of success is far from uniform.