Untreated Onychomycosis Is Associated With Increased Risk of Periprosthetic Joint Infection Following Total Joint...

Onychomycosis, a fungal infection of the nail, is often perceived as a benign condition. The purpose of this study was to evaluate whether onychomycosis is associated with an increased risk of periprosthetic joint infection (PJI) in patients undergoing total joint arthroplasty.

Patients who underwent total knee arthroplasty (TKA) and total hip arthroplasty (THA) were identified using a large national database. Control cohorts of patients who did not have a history of onychomycosis were 1:1 propensity score matched to comparison cohorts of patients who had onychomycosis diagnosed within the year prior to their surgery. The comparison cohorts were further stratified by receipt of antifungal treatment. The 90-day surgical site infection (SSI) and 1-year PJI and reoperation rates were assessed. There was a total of 7,530 patients who had a history of onychomycosis, of which 4,620 patients underwent TKA, and 2,910 patients underwent THA.

Onychomycosis was associated with increased 1-year reoperations [odds ratio (OR): 1.43 (95% confidence interval (CI): 1.04 to 1.97), P = 0.029], but not with SSI or PJI (P > 0.05) after TKA. There were no significant differences in SSI, PJI, or reoperations (P > 0.05) after THA. Subgroup analyses revealed that patients who have onychomycosis and did not receive treatment had an elevated risk of 1-year PJI (both TKA and THA: P < 0.05), with TKA patients demonstrating higher 1-year reoperation rates [OR: 1.57 (95% CI: 1.10 to 2.25), P = 0.013] and THA patients showing a trend toward significance [OR: 1.53 (95% CI: 0.98 to 2.38), P = 0.060].

Untreated onychomycosis was associated with a significantly higher risk of 1-year PJI in patients undergoing total joint arthroplasty and may represent a modifiable risk factor in the preoperative setting. Future research should evaluate whether treatment of onychomycosis reduces the risk of PJI and reoperations.