Can implant retention be recommended for treatment of infected TKA?

Abstract

Background: Retention treatment is reportedly associated with lower infection control rates than two-stage revision. However, the studies on which this presumption are based depend on comparisons of historical rather than concurrent controls.

Questions/purposes: We (1) asked whether the infection control rates, number of additional procedures, length of hospital stay, and treatment duration differed between implant retention and two-stage revision treatment; and (2) identified risk factors that can contribute to failure of infection control.

Methods: We reviewed the records of 60 patients treated for 64 infected TKA from 2002 to 2007. Twenty-eight patients (32 knees) underwent débridement with retention of component, and 32 patients (32 knees) were treated with component removal and two-stage revision surgery. We determined patients' demographics, type of infection, causative organisms, and outcome of treatment. Mean followup was 36 months (range, 12-84 months).

Results: Infection control rate was 31% in retention and 59% in the removal group after initial surgical treatment, and 81% and 91% at latest followup, respectively. Treatment duration was shorter in the retention group and there was no difference in number of additional surgeries and length of hospital stay. Type of treatment (retention versus removal) was the only factor associated with infection control; subgroup analysis in the retention group showed Staphylococcus aureus infection and polyethylene nonexchange as contributing factors for failure of infection control.

Conclusions: Although initial infection control rate was substantially lower in the retention group than the removal group, final results were comparable at latest followup. We believe retention treatment can be selectively considered for non-S. aureus infection, and when applied in selected patients, polyethylene exchange should be performed.

Level of evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Fig. 1

The Kaplan-Meier survivorship curve shows estimated uncontrolled rates of infection were 47% at 6 months, 34% at 12 months, and 20% at 24 months.

Fig. 2

Logistic regression indicated patients without Staphylococcus aureus infection and who have polyethylene (PE) exchange are more likely to control infection after a postoperative infection index procedure compared with the other three subgroups (odds ratio: 25.3, 95% confidence interval: 3.5–18.2, p < 0.001).