Liberal indications for minimally invasive oxford unicondylar arthroplasty provide rapid functional recovery and pain relief

Abstract

The Oxford unicompartmental knee arthroplasty (UKA) was recently approved for implantation in America. Recovery was evaluated and the efficacy of a musculoskeletal hospital was addressed for an initial group of patients who underwent medial compartment UKA with the Oxford device. Between October 2004 and December 2005, 142 medial UKAs were performed in 125 patients and included 11 simultaneous and six staged bilateral UKA procedures, and one simultaneous UKA/TKA procedure. The patients' ages averaged 62 (range: 41-87) years, weight 90 kg, and body mass index (BMI) 31.6 kg/m(2). Sixty-one UKAs were performed in obese patients (BMI >32). The length of stay averaged 1.3 days. In 121 (97%) cases, patients were discharged directly to home. In 23 (18%) cases, home health physical therapy was used. Outpatient physical therapy was used in 95 (76%) cases. Only four (3%) patients required a skilled nursing or post-discharge rehabilitation stay. Five reoperations were required: one revision to TKA for tibial plateau fracture, one revision to TKA for tibial loosening, one radical debridement and staged reimplantation of primary TKA for sepsis, and two arthroscopic procedures (one retained cement, and one synovitis). The average arc of motion at initial six-week follow up was 116 degrees , with 56% of knees having greater than 120 degrees and 82% more than 110 degrees . Absent, or only mild, pain was reported in 85% of knees. Seventy-five percent of patients had good or excellent Knee Society scores by six weeks postoperatively. UKA provides excellent early function and pain relief with rapid recovery when performed at a specialty musculoskeletal hospital. Early discharge appears to be safe and does not transfer the burden of care to other facilities or home health rehabilitation services.