Femoro-Acetabular Impingement (FAI): what is it?
For many years, the exact mechanism responsible for the arthrosis of the hip non-dysplastic in young people, remained unknown.
Thanks to modern imaging techniques and recent arthroscopic techniques, however, a new pathological condition of the hip has been identified; this condition has been identified as FAI (impingment or femoro-acetabular conflict), a condition that promotes the development ofosteoarthritis in the young.
FAI is a conflict between the proximal portion of the femur and the acetabular rhyme resulting from repetitive mechanical impaction during movement, particularly in flexion and intrarotazione; this and can lead to injury of the acetabular labrum and, more seriously, damage to the adjacent acetabular cartilage.
Types of FAI
Recently, two etiological subgroups of FAI have been identified .
1. PINCER (“pincer-like”): this anatomical conflict may result from bony changes in the cotyloid portion. The acetabulum hugs the femoral head too much and, like a pincer, creates the conflict. In pincer-FAI, which is found in women of about 30-40 years of age, the glenoid cerclage is frequently destroyed, cartilage injury may or may not be found. More or less professional sports activities can trigger even mild alterations and make them symptomatic;
2. CAM (“cam-like”): CAM-FAI is evident in young men, frequently athletes, 20-30 years of age, in whom there is a deep osteochondral lesion of the acetabular rhyme, often with the glenoid rim intact. The anatomical alteration is often a “bump” (protrusion or cam), at the junction between the femoral head and neck, creating a conflict of the acetabular rim.
FAI: how it manifests itself
Apart from a slight limitation in maximum intra-rotation (not always present), FAI does not result in a deficit in hip joint motion.
The onset is a pain often located in the groin area that is felt during walking and in the highest degrees of movement; the pain may also radiate to the naval and to the lateral and anterior region of the thigh.
This hip condition affects girls or boys in their 20s and 30s as well as adults in their 40s.
FAI: the exams
Diagnostic imaging studies show that, in such pathology, a nonspherical femoral head (with a prominent position at its junction with the neck) or a protruding anterior acetabular rhyme is often evident; already from radiographs (with Dunn’s radiographic projection or frog-leg), the existence of the FAI can be best revealed.
R.M. allows visualization of localized damage to the superior acetabular labrum and sometimes to articular cartilage.
FAI: the treatments
Stopping the activity associated with painful movement is the main bloodless treatment. In addition to prosthetic replacement, arthroscopic treatment, by removing the conflict and repairing the tissue, is gaining popularity.
The clinical outcome correlates with the severity of the associated cartilage damage; therefore, this correlation should make people choose early arthroscopic surgical treatment if bloodless treatment has not been beneficial.
The treatment of FAI, therefore, if accompanied by pain, should consider arthroscopic surgical treatment, especially if the patient is younger than 40 years old and the cartilage damage is not advanced. Recent scientific studies have shown greater effectiveness of arthroscopic hip surgery than physiotherapy in improving quality of life.
Want to learn more about FAI and hip arthroscopy? Please feel free to CONTACT ME.
