RESULTS OF HIGH DOSE VANCOMYCIN LOADED SPACERS IN TREATMENT OF INFECTED MASSIVE PROSTHESES

Abstract

With the dramatic improvement of conservative surgery in patients with bone sarcoma, infection becomes 1 of the most devastating complication, leading frequently to amputation. The aim of this monocentric study is to precise the influence of spacer loaded with high doses of vancomycin on late Results: PATIENTS From 1984 to 2007, we operated more than 600 patients (p)with bone sarcoma. Age of p. was 4,5 to 82 years (mean 25 y). Histology was osteosarcoma (304), Ewing (142), chondrosarcomas (148), fibrosarcomas or MFH (23), giant cell tumours in others. In 484 cases, p received chemotherapy, and radiotherapy in 50 cases. The mean follow-up from tumour removal is 15 years.

57 p suffered of deep infection of the material used to reconstruct the skeletal defect. We have seen also 3 p for recurrence of deep infection initially treated elsewhere. Altogether, we treated 60 patients for deep infections.

Methods: 26 p had debridment and cleaning of the pros-thesis and long adapted antibiotherapy as first treatment. When ineffective (23/26), a removal of the prosthesis was performed with immediate replacing the new prosthesis in 19 cases. When infection recurred (16/19) and in all other patients the treatment included a two stages protocol with interposition of a spacer with antibiotic loaded cement during 4 to12 weeks. Until 2004, the spacer was made with gentamycin containing palacos mixed with conventional doses of antibiotics adapted to the germ. From 2004/6 we used high doses of vancomycin (4 g per batch of 40 g) with an average total dose of 11g of vancomycin per spacer. The new prosthesis was placed in a later time, when infection, cutaneous and muscular problems were solved.

Results: At the last control, 15 were amputated, following a mean of 6 ineffective procedures. 45 p. benefited from conservation surgery but a new prosthesis could be inserted only in 43, following a mean of 3.2 surgical procedures, Analysis shows the bad prognostic value of initial radiotherapy, of distal locations, and of insufficient muscular coverage and the better efficacy of high dose antibiotics in spacer. Up to date, none of the high dose antibiotic loaded spacers was followed by amputation

Conclusion: Infection of massive prostheses is the most serious orthopaedic complication of limb salvage. Treatment must be preventive, avoiding any radiotherapy.

Good prognostic factors are early removal of the prosthesis, effective antibiotherapy, improvement of the muscular coverage, and use of spacers with high dose vancomycin.