Implant Associated Local Recurrence in Primary Bone Sarcoma

Hydroxyapatite (HA) covered implants are widely used in orthopedic reconstructive surgery. Their biological benefits were highlighted by several studies in the past decades in which the most important ones are the osteoconductive and osteoinductive capacity, which enhances osteoblast adherence, proliferation and bone extracellular matrix formation. In bone sarcomas the micro-environmental changes are crucial for tumor growth, new bone formation especially in osteoblastic osteosarcomas (OS). Nowadays limb sparing surgery and maintaining the quality of patients life are the main two goals in bone sarcoma treatment. The survival rate of patients with OS has been significantly improved in the past 3-4 decades due to the advanced chemotherapy protocols. The prognosis still depends on the early diagnosis and the histological type of the sarcoma. Tumor removal and reconstruction is a crucial moment for prognosis, studies showed that high grade sarcomas have a greater potential for local recurrence and early distant metastases. Metastasis can occur in early stages, even if there are not detectable at the time of surgery. Furthermore, the micro-environmental changes can facilitate sarcoma cell proliferation even if the tumor resection was performed in macroscopically normal bone tissue. We present a case of osteosarcoma in which local recurrence has occurred despite of chemotherapy and wide resection of the tumor. We can ask the following question can an implant increases the risk of local recurrence in sarcoma surgerys The aim of the study was to understand the underlying molecular pathway for sarcoma cell proliferation in HA covered implants.