Citation, DOI and article data
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 1,2.
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’ 1,3.
Usually, patients present with pain.
Chondral delaminations and carpet lesions are due to excessive shear forces, usually parallel to the articular surface 1,4. The delamination occurs at the junction of the deep, non-calcified and calcified cartilage 1,4.
The carpet lesion is typically found on the acetabular side of the hip joint, located anterosuperiorly, sometimes with extension into the labrum 1.
The presence of fluid between the 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 1.
- T2FS: hyperintense
- IMFS: hyperintense
CT / MR arthrography
Full-thickness fissure with undermining contrast alongside the bone-cartilage interface 1.
Treatment and prognosis
Treatment depends more on the location but includes direct technical fixation 2 or chondral debridement and joint lavage with potentially further following restorative therapy 2.
- 1. Palmer W, Bancroft L, Bonar F et al. Glossary of Terms for Musculoskeletal Radiology. Skeletal Radiol. 2020;49(S1):1-33. doi:10.1007/s00256-020-03465-1
- 2. Kaya M, Hirose T, Yamashita T. Bridging Suture Repair for Acetabular Chondral Carpet Delamination. Arthroscopy Techniques. 2015;4(4):e345-e348. doi:10.1016/j.eats.2015.03.011
- 3. Konan S, Rayan F, Meermans G, Witt J, Haddad F. Validation of the Classification System for Acetabular Chondral Lesions Identified at Arthroscopy in Patients with Femoroacetabular Impingement. The Journal of Bone and Joint Surgery British volume. 2011;93-B(3):332-336. doi:10.1302/0301-620x.93b3.25322
- 4. Pathria M, Chung C, Resnick D. Acute and Stress-Related Injuries of Bone and Cartilage: Pertinent Anatomy, Basic Biomechanics, and Imaging Perspective. Radiology. 2016;280(1):21-38. doi:10.1148/radiol.16142305
- 5. Jannelli E, Parafioriti A, Acerbi A, Ivone A, Fioruzzi A, Fontana A. Acetabular Delamination: Epidemiology, Histological Features, and Treatment. CARTILAGE. 2018;10(3):314-320. doi:10.1177/1947603518768096