Femoral lengthening over a humeral intramedullary nail in preadolescent children

Femoral lengthening over an intramedullary nail has been described in adults. A technique of femoral lengthening over a humeral intramedullary nail in children is described, and the results and complications are presented.

Nine preadolescent patients (average age, nine years and ten months) with femoral length discrepancy were treated with femoral lengthening over a humeral intramedullary nail. After nail insertion, a monolateral external fixator was placed with half-pins either anterior or posterior to the intramedullary nail, and lengthening was performed through a proximal osteotomy.

The femora were lengthened a mean of 6.1 cm (range, 5.0 to 8.0 cm), 19.5% (range, 15.9% to 26.2%) of the preoperative femoral length. Patients had a mean lengthening index of 12.2 days/cm of length (range, 9.5 to 16.9 days/cm of length). Five complications including osteomyelitis, failure of the distal interlocking site, and femoral fracture at the distal end of the nail occurred in four patients; four of the complications led to surgical intervention. No case of proximal femoral valgus secondary to nailing through the greater trochanter had developed by the time of final follow-up. All patients were followed for a minimum of two years postoperatively, with a mean of 128 weeks (range, 111 to 161 weeks).

The technique is effective but has a high rate of complications, including osteomyelitis, which developed in two of the nine patients. No avascular necrosis or proximal femoral valgus was noted.