Osteoarthritis Research Today is a free monthly online journal that collates and summarizes the latest research about Osteoarthritis, including details on treatment, symptoms, causes, medication.

Hip morphology influences the pattern of damage to the acetabular cartilage: femoroacetabular impingement as a cause of early osteoarthritis of the hip.

Beck M, Kalhor M, Leunig M, Ganz R

Department of Orthopaedic Surgery University of Bern, Inselspital, 3010 Bern, Switzerland. martin.beck@insel.ch

Recently, femoroacetabular impingement has been recognised as a cause of early osteoarthritis. There are two mechanisms of impingement: 1) cam impingement caused by a non-spherical head and 2) pincer impingement caused by excessive acetabular cover. We hypothesised that both mechanisms result in different patterns of articular damage. Of 302 analysed hips only 26 had an isolated cam and 16 an isolated pincer impingement. Cam impingement caused damage to the anterosuperior acetabular cartilage with separation between the labrum and cartilage. During flexion, the cartilage was sheared off the bone by the non-spherical femoral head while the labrum remained untouched. In pincer impingement, the cartilage damage was located circumferentially and included only a narrow strip. During movement the labrum is crushed between the acetabular rim and the femoral neck causing degeneration and ossification.Both cam and pincer impingement lead to osteoarthritis of the hip. Labral damage indicates ongoing impingement and rarely occurs alone.

Published 23 June 2005 in J Bone Joint Surg Br, 87(7): 1012-8.
Full-text of this article is available online (may require subscription).

© 2004-2008 Osteoarthritis Research Today. All Rights Reserved.