Effect on knee motion of gradual intramedullary femoral lengthening.

Gradual femoral lengthening causes loss of knee motion due to soft tissue tightness. Lengthening with an intramedullary device would be expected to retain good knee movements since it avoids soft tissue transfixation. To ascertain this we looked at the knee movements recorded in 27 patients before, during and after bilateral simultaneous femoral lengthening using Albizzia nails. The mean gain was 6.2 cm and the mean follow-up 28.6 months. No significant difference was noted between the mean preoperative and final knee flexions (148.3 degrees vs. 148.4 degrees) and the mean preoperative and final knee extensions (2.3 degrees vs. 3.4 degrees). By their last visit, all patients were flexing to at least 120 degrees and only one patient had a flexion deformity over 5 degrees. Thus maintenance of good knee motion and early return to activities is possible when an intramedullary device like the Albizzia nail is used for femoral lengthening.