115. MULTICENTRIC RETROSPECTIVE ANALYSIS OF 45 INFECTED TOTAL SHOULDER ARTHROPLASTIES

Abstract

Purpose of the study: A multicentric study involving ten centres of shoulder surgery collected a retrospective series of 45 patients treated for infection of a total shoulder arthroplasty.

Material and methods: Mean age was 68 years (range 28–88) with 2/3 male. The initial indication was excentred joint degeneration (37%), centred degeneration (5%), necrosis (7%), fracture (34%), excentration without degeneration (12%), rheumatoid disease (5%). The implants were a reversed total prosthesis (59%), a hemiprosthesis (26%), a total anatomic prosthesis (15%). Nineteen patients (46%) had a ‘naive’ shoulder at implantation of the first prosthesis, including 70% without any specific medical condition: 30% fracture (hemiprosthesis) and 50% reversed total prosthesis.

Results: The infection developed immediately after implantation in 76% of the shoulders (abnormal pain, hematoma, early collection, inflammatory scar, early fistula). The preoperative Constant score (26 points) showed pain at 4, function at 8, mobility at 12, and force at 2. Osteolysis was noted in 30%. The infection lasted less than 3 months before revision in 27%, 3 to 12 months in 68%, and more than 12 months in 5%. Blood tests were normal in two patients. Staphylococcus epidermidis was isolated in 29%, Propioni bacterium acne in 31%, and these two germs in 5%, but no germ was identified in 24%. There was no loosening in 69% of the cases, making the revision invasive. A one-phase procedure was performed in 31% of patients and a two-phase procedure in 25%. Repeated wash-outs were performed in 25%. A reversed prosthesis was implanted at revision in 87% of the shoulders. These revisions produced a 22% complication rate and 27% were revised for repeated wash-outs, instability or definitive en bloc resection. An infectious disease specialist was called in for 75% of patients; a two-drug i.v. regimen for 10 days was instituted followed by oral antibiotics for 3 months. Outcome was assessed with more than 24 months follow-up for 26 patients. The Constant score at review was 47 points (pain 12, function 12, mobility 20, force 4).

Discussion: Seventy-seven percent of the patients were considered cured at more than 2 years. The two-phase surgery, undertaken when the infection had lasted 3 to 12 months (40%) or more than 12 months (60%), gave a Constant score at 51% and 100% cure. The one-phase option undertaken for infections lasting less than 3 months (40%) or 3 to 12 months (60%) gave a Constant score at 46% and 50% cure. Simple wash-out required 60% revision (repeated wash-out, or implant replacement) and 67% cure. In the event of complications after revision, the cure rate was 67%. In all, only 6% of the patients were dissatisfied.