Gait analysis in tumor patients after distal femoral resection and implantation of a megaprosthesis.

We analysed nine patients who had had a megaprosthesis implanted into the distal femur and knee joint for treatment of sarcomas. Data obtained from the leg operated on were compared with those from the contralateral side and healthy volunteers. Gait data, kinematics, ground reaction forces and the EMG from five muscles around the knee joint were analysed by means of a video-based analysis system recording data from reflection markers ; a Kistler-plate recorded the GRF and a ten channel surface EMG the muscle activity. Muscle around the knee showed a cocontraction between the extensor and flexor muscles in the thigh and the calf in the operated leg as well as contralaterally. Gait characteristics exhibited a reduced speed, -cadence, and a shorter step. This correlated with a reduced flexion in the hip and knee joint. The GRF exhibited significant changes in the data representing the reduced gait dynamic.