Validity and reliability of the Japanese Orthopaedic Association score for osteoarthritic knees.

Background: A variety of outcome measures are available to evaluate physical impairment and disability in patients with knee osteoarthritis, and most physician-rated measures are not validated. The objective of this study was to assess the validity and reliability of an observer-based knee scoring system of the Japanese Orthopaedic Association (the JOA) commonly used in Japanese clinical practice, and to determine demographic variables affecting the score.

Methods: A consecutive series of 85 patients with primary knee osteoarthritis completed the JOA (four domains pain on walking, pain on ascending or descending stairs, range of motion, and joint effusion), two validated patient-rated measures including the generic instrument of the Medical Outcomes Study 36-Item Short-Form (the SF-36) Health Survey, and the disease-specific scale of the Japanese Knee Osteoarthritis Measure (the JKOM), and a performance based timed-up-and-go test (TUG).

Premature failure of the polyethylene tibial bearing surface of the Interax knee arthroplasty.

Thirty-four patients (37 knees) were treated with the Interax knee arthroplasty. There were 31 female and 3 male patients with a mean age at surgery of 70 years (range, 53-84 years). Premature failure of the polyethylene tibial bearing surface occurred in 9 patients (9 knees).