Anatomy

Pathology

Cartilage damage

Articular cartilage

Surgery

Alternative medicine

Labrum

Osteoarthritis

Acetabular labrum

Femoroacetabular impingement

Femoral head

Arthroscopy

Cartilage

Articular cartilage damage

Medicine

Acetabulum

Journal of Bone and Joint Surgery - British Volume

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.

Hip morphology influences the pattern of damage to the acetabular cartilage