Gait Analysis in Patients with Wide Resection and Endoprosthesis Replacement Around the Knee

Background: Limb salvage surgery with endoprosthesis for bone tumor around the knee is reported to have good functional and oncological outcomes. However, the functional assessment using musculoskeletal tumor society (MSTS) and Toronto extremity scoring system remains subjective. We performed gait analysis as an objective assessment of their functional outcome.

Materials and Methods: Gait analysis was performed in 20 patients with endoprosthesis replacement around the knee. The temporal parameters assessed during gait analysis were walking velocity, stride length, duration of stance, and goniometry of the knee. These parameters were compared with the functional outcome score of the MSTS.

Results: The mean free-paced walking velocity was 0.91 m/s (normal is 1.33 m/s), which was 68% lower than normal gait. The stride length and stance phase were shorter for the affected limb compared to normal (P < 0.05). However, the gait was symmetrical with no difference in stride length (P = 0.148), velocity (P = 0.918), knee flexion (P = 0.465), and knee extension (P = 0.321) between the affected and unaffected limbs. Sixteen patients demonstrated stiff knee gait, two had a flexed knee gait, and only two patients had normal gait during the stance phase. The mean MSTS score was 21. There was significant correlation between overall MSTS scores (P = 0.023), function (P = 0.039), and walking scores (P = 0.007).

Conclusion: Limb salvage surgery with endoprosthesis reconstruction around the knee gives good functional outcome, both objectively and subjectively, as evidenced by the symmetrical gait pattern and significant correlation with MSTS score. Despite decreased walking velocity, stride length, and stance phase of the operated limb, the patient still has a symmetrical gait.