Longitudinal deficiency of the fibula. Operative treatment.

We reviewed the results of early amputation and prosthetic fitting in twenty-five children (thirty-one extremities) who had longitudinal deficiency of the fibula and were managed between 1977 and 1992. The median age at the time of the initial operation was thirteen months (range, eight months to nine years and eight months). The median duration of follow-up was eight years and ten months (range, two years and six months to sixteen years and eleven months). A Syme amputation was performed on fifteen extremities (thirteen children), and a modified Boyd amputation (which included resection of the distal tibial physis) was performed on sixteen extremities (thirteen children). (One child had a Syme amputation on one side and a Boyd amputation on the other and is thus included in both groups). In twenty-seven extremities, simultaneous excision of the fibular anlage was performed to prevent the development of a deformity secondary to the potential tethering effect. In twelve extremities, a diaphyseal osteotomy of the tibia also was performed to correct tibial bowing and to improve the mechanical alignment of the extremity. At the time of follow-up, the patients who had had a Syme amputation had more problems related to reformation of the calcaneus, instability of the heel pad, prosthetic suspension, and excessive length of the residual extremity. The modified Boyd amputation improved the function of the heel pad and the prosthetic suspension and provided the optimum length of the residual extremity. We also found that an early diaphyseal osteotomy of the tibia to correct severe bowing improved prosthetic fitting. This study did not support the concept that early resection of the fibular anlage or a diaphyseal osteotomy of the tibia prevents the development of hypoplasia of the lateral femoral condyle and associated genu valgum deformity.