Modern surgical management of extremity bone sarcomas is governed by limb-sparing surgery combined with adjuvant and neoadjuvant chemotherapy. All the resection and reconstruction techniques have to achieve oncologic excision margins, with survival rates and functional results superior to amputation. The main reconstruction techniques of bone defects resulted after resection are: modular endoprosthetic reconstruction; bone graft reconstruction; bone transport; resection arthrodesis; and rotationplasty. Oncologic resection and modular endoprosthetic reconstruction are the generally approved surgical options adopted for the majority of cases in major specialized bone sarcoma centres. Good basic principles, efficient multidisciplinary approach and sustained research in the field can provide a better future for the challenge posed by extremity bone sarcoma treatment. Cite this article: EFORT Open Rev 2019;4:174-182. DOI: 10.1302/2058-5241.4.180048

Proximal humerus chondrosarcoma is a rare localization of the common primary malignant cartilaginous tumor. Management is based on oncological surgical excision because of the inherent resistance to chemotherapy and radiation therapy. The most important prognostic factors with great impact on treatment strategy are histological grading and localization of the tumor. Proximal humerus chondrosarcoma carries a slightly better prognosis, especially for the low and moderate grade tumors. We present the case of a young patient with proximal humerus chondrosarcoma surgically managed in our Department, with the purpose of underlining the challenges posed by this localization for oncological excision and reconstruction but also the importance of histological grading for the treatment algorithm.

Although most soft tissue tumors are benign, with a high healing rate after surgical excision, there is a variety of malignant tumors with differences in progression and prognosis. The study aimed to assess the survival rate in patients diagnosed with this pathology, based on the patient's characteristics (age, gender, race), as well as the tumor's histological type, differentiation degree, location and size. The retrospective study included a group of 103 patients diagnosed during 2010 and 2017 in our department. Considering the high healing rate of benign tumors, only the group of neoplastic patients (45 cases) was involved in the survival rate estimation, assessing tumor characteristics and individual comorbidities. Within this lot, we emphasized a predominance of neoplasm in patients aged over 50 years (32 cases), men (29 cases), and localization of the neoplasm in the thigh (23 cases). The predominant histopathological type, liposarcoma, was diagnosed in 67% of the cases, with dimensions over 6 cm and with local extension. There have been significant variations in mortality between the different histological subtypes (liposarcoma vs. synovial sarcoma). Local recurrences were showed in 18 cases of liposarcoma in the first 2 years after the surgical excision, with an increased aggressiveness of this neoplasm in men over 50 years. 12 cases developed distant metastasis, and until the end of the study, 7 deaths were reported in 3 cases involving associated comorbidities. The five-year survival is inversely proportional to the extent of the tumor and the local invasion, as well as to the age of the patient. An overall survival rate is difficult to appreciate in the context of a heterogeneous group of tumors so it must be evaluated for every histological subtype taking into account the patient's particularities.

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 patient�s 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.