Keloidosis is Associated with an Increased Risk for Developing Arthrofibrosis After Total Knee Arthroplasty

Arthrofibrosis is a complication of total knee arthroplasty (TKA) and a common cause of aseptic revision TKA (rTKA). Since keloidosis and arthrofibrosis are both fibroproliferative disorders, we hypothesized that a history of keloids may predispose patients to developing arthrofibrosis post-TKA. The purpose of this study was to evaluate the impact of prior keloid formation on arthrofibrosis and rTKA incidence within one and two years post-TKA.

Patients who underwent TKA and had a history of keloids were identified using a national electronic health records database and propensity matched on a 1:1 basis by age, sex, race, ethnicity, Charlson Comorbidity Index (CCI), nicotine dependence, obesity, anxiety, and depression status. Exclusion criteria were post-traumatic osteoarthritis, lower-limb neoplasms, prior arthroscopies, osteotomies, or fractures. Primary outcomes were arthrofibrosis and rTKA occurring within one and two years post-TKA. A total of 1,205 patients were identified in each cohort after matching.

Patients who had a history of keloids demonstrated a statistically significant increase in risk of arthrofibrosis at both one year (4.7 versus 2.2%; relative risk (RR) 2.11, 95% confidence interval (CI): 1.34 to 3.31) and two years (4.7 versus 2.4%; RR 1.97, 95% CI: 1.27 to 3.05) following TKA. Rates of revision TKA did not differ significantly two years after TKA (1.6 versus 1.1%; RR 1.45, 95% CI: 0.73 to 2.96).

In this study utilizing a large national database, history of keloid formation was associated with significantly higher arthrofibrosis rates one and two years post-TKA compared to matched controls. This data is consistent with the sparse literature showing associations between keloidosis and other fibroproliferative disorders with arthrofibrosis. This information may help guide clinicians in their preoperative counseling and postoperative stiffness management.