A femoroacetabular impingement (FAI) is an abnormal contact between pelvis and the neck of femur. It occurs particularly when patient bends his hip and causes damage to the cartilage. In the long term, FAI can lead to the development of osteoarthritis (cartilage destruction) and may require a total hip replacement (THR).

Surgery to treat cartilage damage in the hip aims to maintain joint function and delay the onset of osteoarthritis. Microfracture remains the most commonly used treatment for cartilage lesions. It is a surgical technique for repairing articular cartilage that works by creating tiny fractures in the bone, which in turn stimulate the growth of new cartilage.

Cartilage autografting is a promising alternative to microfracture, offering good results in the knee joint. Cartilage autografting involves the use of autologous cartilage tissue (taken from patient body), which is harvested, ground up and reimplanted in a single surgical procedure to promote the growth of new cartilage and repair.

The published literature lacks large-scale studies comparing autologous cartilage transplantation with traditional joint-preserving surgeries, such as microfracture. This is the reason why this study is set up.

Patients with femoro-acetabular impingement (FAI) often develop acetabular chondral lesions, which can impair joint function and reduce quality of life. If left untreated, chondral lesions can progress to osteoarthritis and thus require total hip arthroplasty.

Joint preservation surgeries for the treatment of hip chondral lesions, aim to maintain joint function and delay the onset of osteoarthritis. Microfracture remains the most commonly used treatment for chondral lesions.

Although microfracture is the reference surgical treatment for acetabular chondral lesions, several clinical studies and systematic reviews have reported higher rates of conversion to THA and lower patient-reported outcomes for microfracture compared to other techniques. Furthermore, microfracture can weaken subchondral bone and increase the formation of subchondral cysts, which may explain its inferior outcomes.

Minced cartilage implantation (MCI) has emerged as a promising alternative to microfracture, providing good outcomes in the knee joint. MCI involves the use of autologous cartilage tissue, which is harvested, minced, and re-implanted in a one-stage surgery to promote chondrogenesis and repair. Only one published study has reported on outcomes of MCI in the hip joint, showing good results for 11 male patients with FAI at 2 years follow-up. Therefore, the published literature lacks large-cohort studies that compare MCI to traditional joint preservation surgeries, such as microfracture.

This is the reason why this Clinical Study is set up. The hypothesis is that MCI will provide better short- to mid-term outcomes than microfracture in patients with acetabular chondral lesions due to FAI.

Inclusion Criteria:

• Patient, male or female, aged 18-50 years old;
• Patient with an acetabular chondral lesion due to FAI, characterised as Beck class 4 or 5, measuring 1-6 cm2;
• Patient with Tönnis grade 0-2;
• Patient who signed the informed consent form and is willing to comply with the protocol requirements based on the investigator's judgment;
• Patient affiliated with a social security scheme;
• Patient able to answer questionnaires and to communicate freely in French

Exclusion Criteria:

• Patient with prior ipsilateral hip surgery;
• Patient with borderline or frank hip dysplasia (lateral centre edge angle <25º);
• Patient with hyperlaxity (Beighton score >7);
• Patient with any concomitant disease or disorder which, in the opinion of the investigator, may put the patient at risk or may influence the result of the study;
• Patient that is pregnant or breastfeeding;
• Patient with protected status under articles L1121-6, LL121-8 and L1122-2 of the French Public Health Code;
• Patient who cannot comply with the protocol requirements based on the investigator's judgment