INFECTION OF MASSIVE PROSTHESES USED FOR BONE CANCER

Abstract

Purpose of the study: Infection is the most severe orthopedic complication observed after conservative surgery. The purpose of this study was to ascertain the incidence and causes of such infection and analyze progress achieved over the last ten years.

Material and methods: From 1983 to 2004, surgical procedures were performed in more than 600 patients with bone sarcomas; 520 underwent reconstruction with a prosthesis and/or massive allow graft and were followed for at least six months. Age ranged from 4.5 to 82 years. Deep infections occurred in 47 patients requiring one or several revisions. Three other cases of infection, in patients initially given in other institutions, were included in the series. The study population thus included 50 deep infections after massive reconstruction. Forty-five of these patients had received chemotherapy and 20 radiotherapy. All patients were given adapted antibiotic therapy. Four patients required emergency amputation, and cleaning was attempted in 26. When the infection persisted, or when the infection became chronic, implanted material was removed systematically with insertion of an antibiotic-loaded spacer (gentamycin alon before 1990 then gentamycin+vancomycin). Reimplantation was attempted three to six weeks later when the laboratory results were satisfactory and the muscular and cutaneous situation was sufficient.

Results: Mean follow-up after infection was 8.5 years. At last follow-up, amputation had been necessary in 21 of the 50 patients. The limb was intact in the 29 others but the prosthesis could be reimplanted in only 27 after an average of 2.4 operations. The statistical analysis demonstrated that radiotherapy is a factor of poor prognosis (14 amputations in 20 radiotherapy patients versus 7 amputations in 30 patients without radiation) and that adjunction of vancomycin into the spacer cement has a beneficial effect (15 amputations in 23 patients without vancomycin versus 6 amputations in 27 patients with vancomycin.

Conclusion: Infection of a massive prosthesis is the most serious orthopedic complication because limb survival is compromised. Preventive treatment is crucial: radiotherapy should be avoided and duration of aplasia limited by the use of hematopoietic growth factors. Curative treatment can be achieved with early removal of implanted material, surgical cover with a muscle flap, and adjunction of vancomycin to the spacer cement. The role of prolonged systemic antibiotics remains controversial.