RISK-FACTORS FOR LOCAL RECURRENCES AFTER LIMB-SALVAGE SURGERY FOR HIGH-GRADE OSTEOSARCOMA OF THE EXTREMITIES

Background. Improvements in preoperative staging as well as in chemoth erapeutic regimens have made limb-salvage surgery a reliable modality of treatment for high-grade osteosarcomas of the extremities, with loc al recurrences in most series of less than 10% after this type of surg ery. The quality of surgical margins and local response to preoperativ e chemotherapy are known to be the most significant factors in recurre nce [1, 8-10, 12], and complications related to the biopsy procedure m ay also be a significant factor. The study reported here comprised a h istopathological analysis of our recurrent cases as part of an effort to identify the impact of each of the factors cited above. Materials a nd methods. Five hundred fourteen cases of high-grade, non-multicentri c osteosarcoma of the extremities were treated at the Istituto Ortoped ico Rizzoli between March 1983 and August 1991. In this study we analy zed 23 cases of local recurrence in patients with classic osteosarcoma who underwent limb-salvage procedures. Results. In 15 cases we found correlation between the site of local recurrence and the site where th e margins were less than wide. In five cases the recurrence was second ary to complications of the biopsy procedure (hematoma, delayed healin g). In one case we suspect a previously undetected skip lesion. In the remaining two cases no clear explanation was found for the recurrence . There was also a statistically significant difference in the time of appearance of recurrences related to the tumor response to chemothera py. Conclusions: For only two cases of recurrence was there no clear e xplanation. In one we suspect an undetected skip metastasis, and in th e other there were certain factors which may have increased its risk o f recurrrence (non diagnostic trochar biopsy followed by an incisional biopsy, fair tumor necrosis, recurrence in a 'problem' anatomical sit e, i.e., the popliteal space). In the remaining cases the following fa ctors were found to be directly related to the development of a local recurrence: a) the quality of the surgical margins, b) site of the bio psy as well as complications related to the biopsy procedure, c) local response to preoperative chemotherapy.