Bone-patellar tendon-bone allograft reconstruction for peri-patellar tendon sarcomas: case series.

INTRODUCTION Reconstruction after wide resection for a sarcoma involving the knee extensor mechanism is challenging even if the tumor is small. CASE DESCRIPTION We report on four consecutive peri-patellar tendon sarcomas treated similarly at a single institution. Histological diagnoses were synovial sarcoma (two cases), clear cell sarcoma and extraskeletal Ewing's sarcoma (one case each). Follow-up periods after surgery were 18-67 months. All cases underwent pre-operative radiotherapy and subsequent surgery. After preoperative radiotherapy and wide resection including the patellar tendon, bone-patellar tendon-bone allograft was fixed to the residual patella and tibial tuberosity with screws and a cable wire. Soft tissue and skin defect over allograft was covered by free antero-lateral thigh flap. Post-operatively, the operated knee was splinted straight for at least 6 weeks, and then range-of-motion exercise was gradually introduced. Except for one case with a proximal tibial stress fracture 5 months post-operatively, no complication was observed. Both bone-bone junctions between allograft and residual bones were united within 1 year after surgery. At the latest clinical follow-up, all the patients had satisfactory functions with Musculoskeletal Tumor Society score of 28-30 out of 30 points and virtually full range of motion. DISCUSSION AND EVALUATION This case series is the first to report bone-patellar tendon-bone allograft for reconstruction after tumor resection with joint preservation and with satisfactory clinical outcomes. CONCLUSIONS Bone-patellar tendon-bone allograft reconstruction with vascularized flap reconstruction is a viable option for peri-patella tendon sarcomas.