|Beitragstitel||Salvage of massive Giant Cell Tumor of the Proximal Tibia using a fresh osteochondral Allograft|
The transplantation of osteochondral allografts is a joint preserving procedure for large combined defects of the subchondral bone and cartilage that furthermore facilitates the reestablishment of hyaline cartilage. Indications include posttraumatic defects, osteonecrosis, osteochondritis dissecans and tumors, mainly of the ankle and knee. Here we present a case of a patient with a massive Giant Cell Tumor (GCT) of the proximal tibia, treated with resection and reconstruction with fresh osteochondral allograft.
A 35 year old male patient presented with left medial knee pain for 4 months. Imaging revealed a 64x57x55 mm expansive, heterogenous, partially liquid lesion with cortical arrosions of the left proximal tibia. Biopsy showed multinucleated giant cells of the osteoblastic type. Curettage of the meta- and diaphysis including the subchondral bone but preserving the joint cartilage as well as cementation was performed. Postoperatively denosumab treatment was used. During the following 24 months, progressive destruction of the articular surface occurred. To postpone arthroplasty the decision was taken to transplant a fresh osteochondral allograft and medial meniscus.
The medial collateral ligament was separated and kept in the soft tissue sleeve en bloc. The cement was completely removed and the cartilage of the medial tibial plateau together with the meniscus resected. The defect of the proximal tibia was prepared and the allograft adjusted so that a proper axis in extension and medial stability was achieved. As the allograft was 3-4 mm underdesigned the intercondylar region was slightly widened. To correct the slope a small wedge was placed in the dorsal diaphysis. The osteochondral allograft was reduced, the meniscus secured to the capsule with sutures, the medial collateral ligament fixed and a Tomofix plate placed. At 2 years follow-up, the patient showed a remarkable functional outcome being able to walk without crutches, impaired only by residual medial instability, and was fully reintegrated to his standing profession.
Giant cell tumors of the bone are characterized by aggressive growth. Joint involvement often ends in arthroplasty. Especially for young patients, transplantation of an osteochondral allograft might delay joint replacement and can provide good functional outcome in selected cases.