**5. Conclusion**

*Recent Advances in Bone Tumours and Osteoarthritis*

Frozen autografts recycled in liquid nitrogen are a biologic solution with the advantages of low cost, easy access, complete removal of viable tumor, bone morphogenic protein preservation, osteoconduction and osteoinduction properties maintained, perfect matching at the osteotomy site, does not require a bone bank, allows reattachment of tendons and ligaments, no disease transmission and no graft rejection (**Figure 7**) [47]. Among its disadvantages, the bone piece cannot be sent for full pathology analysis and thus provide the information about the percentage of necrosis obtained after systemic treatment in the indicated cases. Nonetheless, the surrounding soft tissues which are resected prior to submerging the piece in LN are sent to pathology. This technique accomplishes full necrosis of the tumoral cells and prior studies have shown that the soft tissue resection prior to the sterilization in LN is representative of the tumor response to chemotherapy [48]. Additionally, this procedure has shown no difference in terms of bone resistance to compression when compared to unfrozen bone. This allows for the initial resistance of the reconstruc-

*Radiographic image depicting a pathological fracture through a distal femur osteosarcoma with displacement* 

One particular scenario, the treating orthopedic oncologist should be aware of is the case of an osteosarcoma with a pathological fracture at presentation. Fractures through an osteogenic sarcoma can occur in up to 10% of the cases (**Figure 8**) [14]. In the past, this circumstance used to be a contraindication for a limb salvage procedure and patients were indisputably recommended for an amputation. Nowadays, even though those patients tend to present a worse prognosis, a limb salvage procedure is considered an option with similar recurrence rates when compared to amputations [49]. Prior studies presented the hypothesis that these patients may have a worse outcome due to a hematoma formation at the fracture site, with tumor cell dissemination [50]. Although the ideal treatment is controversial, some authors recommend stabilization of the fracture, which could be achieved by casting, external fixation or limited internal fixation followed by neoadjuvant chemotherapy, subsequent definite surgical treatment and adjuvant systemic treatment [51, 52]. Radiotherapy has a role for unresectable tumors or in cases of positive margins to help with local control. The Cooperative Osteosarcoma Study Group (COSS) has presented promising results for the case of unresectable osteosarcomas of the spine and pelvis where the treatment with radiation with a curative intent improved the 5-year survival from 0 to 29% [53, 54]. Additional studies have shown radiation is well tolerated by the patients and can achieve up to 76% local control rates [55]. These findings seem to indicate osteosarcomas do have at least a moderate response

tion, being comparable or even superior to allografts [48].

**80**

**Figure 8.**

*and shortening of the distal fragment.*

Osteosarcoma, the most common primary bone malignancy in children and adolescents, has come a long way since its initial approach where all patients underwent an amputation prior to the 1970's. Current systemic treatment options along the myriad of reconstruction alternatives, have allowed these patients to benefit from better survival rates and improved function and quality of life. Nonetheless, the overall survival rates have remained stable for the past 50 years, a disappointing number when compared to other malignancies' statistics, suggesting more resources and research are needed to continue enhancing the outcomes of patients suffering from this cancer.
