S09.2 PROSTHETIC JOINT INFECTIONS – REALITY CHECK

Abstract

Introduction: Prosthetic joint infections are a growing burden. Since we felt that we were far from the optimistic results recently published, we decided to find out the reality in our department. The goals were to determine:

1. The rate of infections in primary and revision surgery (hip and knee)

2. The success rate in treating those infections

3. Long term survival rate of revision arthroplasties

Materials and Methods: We retrospectively reviewed clinical records of all patients that underwent surgical treatment due to infected hip or knee prosthetic joint between 1st July 2001 and 31st December 2007.

Results: Since the majority of infections (67%) presented in the first two years after surgery, we determined the rate of infections taking in to consideration a minimum two years follow-up. We calculated a 1.8% (12/678) rate of infection for primary total hip and 3.3% (20/588) for primary total knee arthroplasty. There was no statistically significant difference between the two groups. Revision hip surgery had a 5.4% (15/243) infection rate and revision knee surgery revealed an even higher rate of 10.3% (4/42). The difference between primary and revision surgery was statistically significant both for hip and knee.

Considering an infection free arthroplasty as the goal, the overall success rate of treatment was under 48% (30/69). The success of treating infections with debridement and retention of components was even lower (29%). Further analysis revealed a higher success of this approach (45%) when considering more appropriate candidates (short term infections). An interesting statistically significant difference was found favoring this approach in the knee.

Two-stage revision strategy was successful in achieving revision arthroplasty in 43% (20/46) of the cases. Most patients were never considered candidates to the second stage procedure. Knee joint and resistant microorganisms were found to be predictors of bad prognosis.

There was a 90% (18/20) survival rate of revision arthroplasties after two years average follow-up. There were only 2 cases of relapsing infection both controlled without prosthetic removal.

Conclusion: Our results compare poorly with the latest published data from different centers. They led us to implement new prophylactic measures as well as review our diagnostic and treatment options.