INFECTION AFTER SHOULDER PROSTHESIS

Abstract

Purpose: The purpose of this study was to analyse the epidemiology, management, and cure rate in 49 infected shoulder prostheses.

Material and methods: This retrospective multicentric study included 2396 shoulder prostheses with at least two years follow-up (mean 34 months): 2146 first intention prostheses and 250 revision prostheses. Results were analysed as a function of: — time to development of infection: 12 acute (less than 2 months after surgery), 6 subacute (2 to 12 months after surgery), and 29 chronic (more than one year after surgery); — cause leading to the first intention implantation; — therapeutic management of the infection.

Results: Two patients died and five were lost to follow-up. The results were thus evaluated in 42 patients. The rate of infection in this series was 1.8% for first intention prostheses and 4% for revision prostheses. Fracture, joint degeneration with massive rotator cuff tears and radiation-related necrosis were factors of high risk of infection (25% for radiation-related necrosis). Thirty patients achieved cure (71%). Three patients had a doubtful cure and nine patients remained infected (29%). The Constant score moved from 20 points before revision to 38 points. Active elevation was below the horizontal (74°). Eighty percent of the acute infections were cured but one-third of the cases required a new revision. Single-procedure replacements provided better functional results and better cure rates. There was a strong correlation between early surgical intervention, adapted antibiotic treatment, and rate of cure.

Discussion: The overall rate of infection in this series is comparable with data in the literature. The rate of certain cure of infection was disappointing (71%). For acute infections, the patients underwent surgery too late and treatment was too aggressive. If there is a doubt about possible infection, revision should be performed as early as possible to allow cure and preserved function. For chronic infections, time to diagnosis and management was too long. This led to anthroplastic resection in one-third of the patients. The choice of the antibiotics and duration of treatment, associated with rigorous surgical technique, should allow switching from arthroplastic to resection prosthetic replacement using one or two surgical times which, for these infected shoulder prostheses, appears to offer the best compromise between cure and function.