Abstract. Functional reconstruction following a wide resection for a malignant musculoskeletal tumor is often challenging, particularly for juxta-articular tumors. The current study describes a novel surgical procedure for the functional reconstruction of the knee extensor mechanism with a pedicle frozen auto-bone and -tendon graft, in a case of prepatellar clear cell sarcoma. The active range of motion of the knee was from 0-135˚, and the extension muscular strength of the knee was evaluated as 5/5 by a manual muscle test at 14 months post-surgery (International Society of Limb Salvage score, 73%); this was improved compared with a similar procedure previously described by Muramatsu et al. This procedure must be considered following the wide resection of juxta-articular malignant musculoskeletal tumors.