Activity Level Does Not Affect Survivorship of Unicondylar Knee Arthroplasty at 5-Year Minimum Follow-Up

Patients are often cautioned against a high level of activity after knee arthroplasty. The purpose of this study was to report on implant survivorship and outcomes of high-activity patients compared with low-activity patients after unicondylar knee arthroplasty (UKA).

We identified 487 patients (576 knees) who underwent UKA with the Oxford mobile bearing knee (Zimmer Biomet, Warsaw, IN) with a 5-year minimum follow-up. Patients were divided into 2 groups: low activity (LA) (University of California Los Angeles ≤6) and high activity (HA) (University of California Los Angeles ≥7). Preoperative and postoperative range of motion, Knee Society scores, complications, and reoperations were evaluated.

Mean follow-up was 9 years (range, 4 to 13.1). The HA group had significantly more male patients, were younger, and had higher knee society clinical scores and knee society functional scores preoperatively. The HA group had significantly higher improvements in Knee Society scores and pain postoperatively. Revisions were performed in 8.4% of the LA group and 6.2% of the HA group ( P = .43). At our mean of 9-year follow-up, there was 94.0% survival for the HA group and 92.1% for the LA group ( P = .6085).

Highly active patients had no increased risk of revision after UKA with the Oxford mobile bearing knee at 5-year minimum follow-up.