Lower Extremity Acute Bacterial Skin and Soft Tissue Infection Following Total Knee Arthroplasty.

Background: Although total knee arthroplasty (TKA) is one of the most common orthopedic procedures, its association with subsequent acute bacterial skin and soft tissue infections (ABSSTIs) in the ipsilateral limb has not been studied.

Methods: This was a retrospective study of patients with prior unilateral TKA who were diagnosed with ABSSTI 4 weeks or more postoperatively in the absence of surgical site infection. The odds of ABSSTI in the TKA limb was compared to that of the contralateral "control" limb in the same patient in the presence or absence of local predisposing factors for ABSSTI in the lower extremities (e.g., chronic venous insufficiency).

Results: Of 94 patients studied, 58 (62%) were women; mean age was 74.5 years. The mean body mass index was 33.1kg/m(2). One or more local predisposing factors were present in 53 (56.4%) patients. The mean interval between TKA and ABSSTI was 65.1 months (range: 1-239 months), with cellulitis alone diagnosed in 88 (94%) patients. ABSSTI involved the TKA limb of 68 (72.3%) patients and was significantly more likely to be diagnosed in the same limb in the absence of local predisposing factors (36 of 41 patients, odds ratio = 7.2, 95% CI: 2.8-23.5); the odds of TKA limb involvement was also higher in the presence of such factors but did not quite reach statistical significance (odds ratio = 1.5, 95% CI: 0.8-2.8).

Conclusions: TKA appears to predispose to ABSSTIs in the ipsilateral lower extremity often years after the procedure, particularly in the absence of other local factors.