Carpet lesion
Carpet lesion is a term for focal a chondral delamination, where articular cartilage is peeled off the subchondral bone plate as a result of shearing forces. It is a frequent finding on hip arthroscopy and is associated with femoroacetabular impingement .
Terminology
The carpet lesion was given its name by its arthroscopic appearance, where it was compared to an undulating carpet also known as ‘carpet phenomenon’ or ‘wave sign’ .
Clinical presentation
Usually, patients present with pain.
Pathology
Chondral delaminations and carpet lesions are due to excessive shear forces, usually parallel to the articular surface . The delamination occurs at the junction of the deep, non-calcified and calcified cartilage .
Location
The carpet lesion is typically found on the acetabular side of the hip joint, located anterosuperiorly, sometimes with extension into the labrum .
Radiographic features
MRI
Presence of fluid between articular cartilage and the subchondral bone plate is indicative, however, the diagnosis is challenging because often cartilage shows normal thickness and contours, and in joints like the hip the detection of fluid accumulation is often limited, without applying traction .
T2FS: hyperintense
IM: hyperintense
CT / MR arthrography
Full-thickness fissure with undermining contrast alongside the bone-cartilage interface .
Treatment and prognosis
Treatment depends more on the location but includes direct technical fixation or chondral debridement and joint lavage with potentially further following restorative therapy .
See also
