title: Radiographic measurement of joint space height in non-osteoarthritic tibiofemoral joints. A comparison of weight-bearing extension and 30 degrees flexion views.
abstract: There have been many reports which suggest that in patients with tibiofemoral osteoarthritis, a reduction in joint space is demonstrated better on weight-bearing radiographs taken with the knee in semiflexion than in full extension. The reduction has been attributed to the loss of articular cartilage in the contact area in a semiflexed arthritic knee. None of these studies have, however, included normal knees. We have therefore undertaken a prospective, double-blind, randomised study in order to evaluate the difference in the joint-space of arthroscopically-proven normal tibiofemoral joints as seen on weight-bearing full-extension and 30 degrees flexion posteroanterior radiographs. Twenty-two knees were evaluated and the results showed that there may be a difference of up to 2 mm in the two views. This difference could be attributed to the inherent differential thickness of the articular cartilage in different areas of the femoral and tibial condyles and a change in the areas of contact between them.
mesh_terms: D000293:Adolescent; D000328:Adult; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology; D011446:Prospective Studies; D011859:Radiography / Q000379:methods; D012016:Reference Values; D016474:Weight-Bearing