Classification of Acetabular Cartilage Lesions

Acetabular cartilage lesions are frequently found during hip arthroscopy. The arthroscopic view offers an exceptional perspective to assess cartilage injuries especially in their early stages. We know that articular cartilage damage occurs progressively up to the development of hip osteoarthritis requiring joint replacement. Numerous studies have shown that advanced cartilage damage is an indicator of a bad prognosis when performing hip arthroscopy. It is important to identify before surgery patients with advanced cartilage damage that are not candidates for a hip preservation procedure (hip arthroscopy). In addition to clinical evaluation, Radiology is very useful to estimate the degree of arthritis (Tönnis Classification); narrowing of joint space (<2 mm) advanced chondral damage. Magnetic Resonance Imaging (MRI) is also useful for assessing cartilage damage. The formation of subchondral cysts and acetabular bone edema are signs of poor prognosis corresponding to significant damage of the articular cartilage. Nowadays there are advanced techniques to determine with more accuracy the damage of the articular cartilage prior to a possible hip arthroscopy (T-2 Mapping, G-Gemric). However, arthroscopic vision is considered more accurate to assess acetabular cartilage damage, especially in early stages. For a correct evaluation of these different stages of chondral damage, a proper classification is necessary to describe these lesions in a simple and reproducible manner.