Your hip joint is a relatively tight fitting ball and socket joint. There are primarily three conditions that affect this joint: labral tears, impingement and arthritis (or chondral lesions). All three of these conditions tend to be characterized by groin pain but each has a distinguishing feature.
These are diagnoses that are relatively difficult to confirm accurately and require physicians that are skilled in diagnosing the condition. Dr. Mark Frederickson at Stanford University is a well known physician specializing in running related injuries. Dr. Mark Philomen at the Steadman-Hawkins Clinic in Vail Colorado is one of the top orthopedic surgeons that treat these conditions.
The Labrum is a disc shaped cup in the socket of your hip joint. Its function is to provide cushioning to the joint and improve the fit of the joint. Recent improvements in MRI technology have made it possible to view these tears and arthroscopy techniques have made it possible to trim up the tear and occasionally sew the tear back together. The distinguishing symptom of a labral tear is clicking inside the hip joint when your leg is rolled inward and outward while lying on your back. Other typical symptoms are a sensation of locking, catching or giving away in the hip. Research suggest that approximately ¾ of people are satisfied with the results of arthroscopy for a labral tear. Labral tears are also often associated with chondral defects (an erosion or divot in the cartilage of either the ball or the socket). One study reported that 74% of people with a labral tear also have a chondral lesion.
Chondral Lesion / Arthritis
The ball and socket of your hip joint are covered with articular cartilage which is an incredibly slick and resilient surface. Occasionally this smooth surface gets a divot or erosion in the surface, somewhat similar to what happens to my Teflon pans (especially when I use a metal spatula). If the chondral lesion is relatively small (approximately 400mm squared) then a procedure called microfracture is used to stimulate healing of the defect. The microfracture technique consists of drilling into the bone in the area of the divot to stimulate bleeding or drainage of bone marrow. The bleeding brings chondrocytes (cartilage forming cells) to the area and hopefully new cartilage forms. Unfortunately, the new cartilage will never be as good as the original.
Arthritis is more advanced cartilage breakdown and is too extensive for microfracture to be effective. Arthritis tends to result in stiffness experienced primarily in the morning and pain that is in the area of the inner thigh.
Femoral Acetabular Impingement
Impingement is a term used to describe pinching of the tissues around a joint. In the case of the hip joint, either the ball is shaped abnormally and pinches against the cup (acetabulum) or the cup has developed a ridge that the ball pinches against. Arthroscopic surgery can be performed to remove the ridge or alter the shape of the ball.
Stanford Medical Center Division of Physical Medicine
Rehabilitation Department of Orthopaedic Surgery
300 Pasteur Drive Edwards Bldg. R-107A
Stanford , CA 94306
Phone (650) 498-7555