BUGGED OUT? INFECTION AND ENDOPROSTHETIC REPLACEMENT

Abstract

Endoprosthetic replacement (EPR) following Bone Tumour excision is common. A major complication of EPRs is infection, which can have disastrous consequences.

This paper investigates the cause of infection, management and sequelae.

Over 10, 000 patients have been treated in our unit over 34 years. Information collected prospectively on a database includes demographic data, diagnosis, treatment (including adjuvant), complications, and outcomes. Data was analysed to identify any infection in EPRs, its management and outcome. Factors such as operating time, blood loss, adjuvant therapy, type of prosthesis (extendable or standard) were investigated. Outcomes of treatment options were evaluated. Data was analysed on 1265 patients undergoing EPR over 34 years, giving a total follow up time of over 6500 patient years.

137 (10.8%) patients have been diagnosed with deep infection (defined by a positive culture [n=128] or a clinically infected prosthesis with pus in the EPR cavity [n=9]). Of these 49 (34%) required amputations for uncontrollable infection. The commonest organisms were Coagulase Negative Staphylococcus, Staphylococcus aureus and Group D Streptococci. The only satisfactory limb salvaging operation was 2 stage revision, which had 71% success in curing infection. Systemic antibiotics, antibiotic cement or beads and surgical debridement had little chance of curing infection. Infection rates were highest in the Tibial (23.1%) & Pelvic (22.9%) EPRs (p< 0.0001). Patients who had pre or post-operative radiotherapy had significantly higher rates of infection (p< 0.0001), as did patients with extendable EPRs (p=0.007).

Patients who had subsequently undergone patella resurfacing and rebushing also had a higher rate of infection (p=0.019 and p=0.052). Infection is a serious complication of EPRs. Treatment is difficult and prolonged. 2 stage revision is the only reliable method for limb salvage following deep infection. Prevention must be the key to reducing the incidence of this serious complication.