Radiographic Narrowing of the Lateral Compartment at 10 to 18 Years After Medial Unicondylar Arthroplasty: Has the Role of Knee Alignment Been Overstated?

Methods: One hundred seven unicompartmental arthroplasties were implanted in 1985-1995 and had 10 to 18 years of radiographic follow-up. The lateral compartment joint space width was measured from weightbearing anteroposterior radiographs made during postoperative year 1 and at the most recent examination. Postoperative year 1 hip-knee-ankle angle, postoperative year 1 lateral compartment joint space width, tibial implant thickness, polyethylene shelf age, sex, weight, and age were examined as risk factors for narrowing.