Is Mobile-Bearing Medial Unicompartmental Knee Arthroplasty Appropriate for Asian Patients With the Risk of Bearing Dislocation?

Background: Mobile-bearing unicompartmental knee arthroplasty (UKA) is an attractive operation for medial unicompartmental knee arthritis, but unexpected bearing dislocation is a drawback. Bearing dislocation occurs more frequently in Asians, whose lifestyle involves deeper knee flexion than Westerners. This study investigated whether mobile-bearing medial UKA is appropriate for Asians by analyzing (1) the rate of bearing dislocation and (2) the results of patients with bearing dislocation.

Late Mobile-Bearing Dislocation in Unicompartmental Knee Arthroplasty.

The authors present 2 cases of late mobile-bearing dislocation after unicompartmental knee arthroplasty with long-term follow-up. Patients had anterior bearing dislocation more than 10 years after primary unicompartmental knee arthroplasty. Retrieved mobile bearings showed severe erosion on the posterior lip, suggesting frequent deep knee flexion as the cause of wear.

Total Knee Arthroplasty for Severe Flexion Contracture in Rheumatoid Arthritis Knees.

Flexion contracture deformities, as well as severe varus and valgus deformities of the knee joint, accompany osteoarthritis or rheumatoid arthritis (RA). In particular, severe flexion contracture deformity of the knee joint is often found in patients with RA, which renders them nonambulatory. This report describes a 26-year-old female patient diagnosed with RA 10 years ago.