Article

Anterior femoroacetabular impingement can cause early hip osteoarthritis. The
typical patient is an adult younger than 50 years of age, often with a history of
sporting activities. The main symptom is intermittent pain triggered by static
flexion (low seats) or dynamic flexion (during sporting or occupational
activities that require repeated hip flexion). The characteristic physical
finding is pain triggered by placing the hip in internal rotation and 70 to 110
degrees of flexion. In additional to anteroposterior and false-profile
radiographs, lateral Dunn or Ducroquet views should be obtained on both sides to
visualize the anterior part of the head-neck junction. Instead of being concave,
the head-neck junction is either flat or convex, causing a cam effect that
damages the labrum and anterosuperior cartilage.
Non-sphericity of the femoral
head with an anterior ovoid bulge induces a similar cam effect. In pincer
impingement, which is less common, over-coverage by the anterosuperior acetabular
rim pinches the labrum between the rim and the femoral head-neck junction when
the hip is flexed. Pincer impingement is related to acetabular retroversion or
protrusion. Arthrography coupled with computed tomography or magnetic resonance
imaging visualizes the morphological abnormalities (e.g., ovoid shape of the
femoral head or retroversion of the acetabulum) and detects secondary lesions
such as labral tears or separation or damage to the anterosuperior cartilage.
Arthroscopy allows removal of the damaged labrum and correction of the
morphological abnormalities via femoroplasty to restore the normal concave shape
of the neck and/or acetabuloplasty to eliminate over-coverage. Short- or mid-term
results are satisfactory in 75 to 80% of patients. However, the presence of
degenerative lesions in about two-thirds of patients at the time of arthroplastic
surgery limits the probability of achieving good long-term results.
CI - Copyright (c) 2012. Published by Elsevier SAS.

Langue : ANGLAIS