Long-term results of acute prosthetic joint infection treated with debridement and prosthesis retention: a case-control study

Purposes: To evaluate the long-term outcome (at least 4 years) of patients who underwent a surgical debridement due to an acute prosthetic joint infection (PJI) and to compare them with a control group that did not have an acute septic complication. Methods: From January 1999 to December 2007, 61 patients with an acute PJI in remission after 2 years of follow-up (cases) were retrospectively reviewed and compared with a control group (2:1) without an acute PJI matched by age, year of arthroplasty, and type of prosthesis. Septic and aseptic complications of each group were gathered and compared using a chi-square test. A two-tailed p value <0.05 was considered statistically significant. Results: Out of 183 patients, 4 cases and 2 controls were excluded due to death or lost to follow up; 113 (63.8%) were females and 109 (61.5%) had a knee replacement. The mean age and time of followup were 68.3 and 6.4 years, respectively. There were no statistically significant differences between cases and controls in the percentage of late septic or aseptic loosening. However, the late relapse rate in patients with acute PJI caused by S. aureus, was 12.5% (2 out of 16) and there was a trend towards significance when compared with the rest of the cohort (3.3%, p = 0.09). Aseptic late complications were more frequent in GN-cases (10.7%) than in the other groups (3.4% in GP-cases and 5% in controls) but this difference was not statistically significant (p = 0.19). Conclusions: In conclusion, although analyzing all late complications together, patients with an acute PJI have a similar long-term outcome in comparison with controls; patients with an acute PJI due to S. aureus had a higher late relapse rate; and GN-cases developed an aseptic loosening more frequently. In the future, it is necessary to evaluate larger series to confirm our results.