Progress in muscle strength of the reconstructed knee and quality of life of the patient after knee rotationplasty: A case report

Abstract

Knee rotationplasty (KRP) is a function-preserving surgery that serves as an alternative to above-knee amputation in patients diagnosed with malignant bone and soft tissue tumors around the knee joint. However, the short-term progress of the reconstructed knee in terms of muscle strength is unclear after KRP. This case report describes the progress of a 37-year-old man diagnosed with synovial sarcoma in the distal femur, 1 year after undergoing KRP. Changes in muscle strength of the reconstructed knee and physical function are reported. Physical therapy was started on postoperative day 1 after the KRP, and mobilization proceeded step-by-step with sitting, wheelchair transfer, and crutch walking. Active and passive range-of-motion exercises of the reconstructed knee were started on postoperative day 5. The isometric reconstructed knee extension strength, 10-m walk test, timed up and go test, Musculoskeletal Tumor Society score, Toronto Extremity Salvage Score, and quality of life (QOL) were evaluated. One month postoperatively, muscle strength had increased, and at 6 and 12 months postoperatively, isometric knee extension strength and physical function had improved. Furthermore, activities of daily living and QOL gradually improved over the course of the 12 months. Our case shows the previously unknown course of reconstructed knee muscle strength in the early post-KRP period, with corresponding improvements in physical function, activities of daily living, and QOL.