Is it always the case that if you have femoroacetabular impingement (which I have) that arthritis will eventually set into that hip?
Not necessarily though many individuals with femoroacetabular impingement (FAI) do indeed eventually develop degenerative changes that lead to arthritis. This is most likely to happen in cases of untreated FAI.
Let's define femoroacetabular impingement and talk about how it can lead to osteoarthritis of the hip joint. Impingement refers to some portion of the soft tissue around the hip socket getting pinched or compressed.
Femoroacetabular tells us the impingement is occurring where the femur (thigh bone) meets the acetabulum (hip socket). There are several different types of impingement. They differ slightly depending on what gets pinched and where the impingement occurs.
The cam-type of impingement is the most likely to set up conditions ripe for joint wear and tear. This type occurs when the round head of the femur isn't as round as it should be. It's more of a pistol grip shape. It's even referred to as a tilt or pistol grip deformity. The femoral head isn't round enough on one side (and it's too round on the other side) to move properly inside the socket.
The result is a shearing force on the labrum and the articular cartilage, which is located next to the labrum. The labrum is a dense ring of fibrocartilage firmly attached around the acetabulum (socket). It provides depth and stability to the hip socket. The articular cartilage is the protective covering over the hip joint surface. This abnormal contact between the femur and acetabulum is the leading cause of labral tears and degenerative hip arthritis.
Treatment is advised when impingement is painful, limits function, and/or X-rays show potential for joint changes. You may be able to follow a conservative path by modifying activities and carrying out a program of strengthening and stretching exercises. In some cases, surgery is indicated to correct the problem.
No one knows for sure who will develop arthritis. Studies are underway to determine how common is the problem and what factors might increase the likelihood of developing arthritis. Your orthopedic surgeon will follow your case and advise you if and when treatment (and what treatment) is appropriate.
Kalesha Hack, MD, et al. Prevalence of Cam-Type Femoroacetabular Impingement Morphology in Asymptomatic Volunteers. In The Journal of Bone & Joint Surgery. November 2010. Vol. 92. No. 14. Pp. 2436-2444.