Medial gastrocnemius muscle flap in limb-sparing surgery of malignant bone tumors of the proximal tibia: mid-term results in 25 patients.

Twenty-five patients in whom the medial head of the gastrocnemius muscle was transposed to cover defects in limb-sparing surgery of malignant bone tumors in the proximal tibia were evaluated prospectively in a tumor register. Surgical technique and mid-term clinical-functional results after a mean follow-up of 4 years 6 months are presented in this study. Twenty-four of the 25 gastrocnemius muscle flaps survived without complications. In 1 patient, infection and necrosis of the transposed muscle developed 10 days after surgery, requiring revisional muscle transposition. The total revision rate after primary tumor surgery was high (48%), but this had no impact on the viability of the transposed muscle flap. The mean Musculoskeletal Tumor Society score at follow-up was 75.1% (range, 20-97%) and the mean postoperative range of motion in the operated knee was 60 deg (range, 30-100 deg). Because of its easy, safe, and quick preparation, the medial gastrocnemius muscle flap is exceptionally valuable as a means of covering defects arising during the course of this extensive tumor surgery. It guarantees a high survival rate of the transposed muscle and supports vascularity of the skin flaps, helps to reestablish joint function and mobility by stabilization and reinforcement of the extensor mechanism, and provides protection against infection.