The acetabular labrum is a ring of fibrocartilage (fibrous cartilage) that encircles the acetabulum (cup) of the hip joint and increases its depth. The head of the femur (the bone in the thigh) fits in the acetabulum. The labrum deepens this cavity and effectively increases the surface (and strength) of the hip joint. The labrum serves to maintain normal forces and function of the joint. An acetabular labrum tear is an injury to that ring of fibrocartilage that leads to abnormal forces and early joint damage, and is a known contributor to the development of arthritis.
What Causes An Acetabular Labrum Tear?
Injuries to the acetabular labrum (or an acetabular labrum tear) can occur from chronic trauma due to repetitive hip motion or from acute trauma as, for example, from a direct blow to the hip or a violent motion of the hip. Femoroacetabular impingement (FAI) also has been associated with the development of hip labrum tears and with articular cartilage injury. Other abnormal bone structures around the hip also can contribute to injury such as Perthes disease, dysplasia, and slipped capital femoral epiphysis (SCFE).
Diagnosis of Acetabular Labrum Tears
Signs and symptoms of an acetabular labrum injury (labral tear) include pain accompanying hip motion, occasional pain in the hip at night or during daily activities, decreased range of motion and loss of strength in the hip. Mechanical symptoms such as grinding, popping, clicking, or snapping also may occur.
Treatment of Hip Labral Tears
Repair of an acetabular labrum tear (labral tear) also has been termed refixation or reattachment. Debridement refers to the “cleaning up” or removal of torn tissue, with the goal of leaving a stable rim of healthy tissue. The labrum can be damaged in many different ways, including by degeneration, instability, radial tears, longitudinal tears, detachment from the rim, and a combination of these. The indications for repair versus debridement of these different types of tears are not entirely clear. However, there is increasing evidence to support improved success with repair versus debridement.
There are a number of studies demonstrated high success rates looking at groups of patients with repairs only, but there are few studies comparing these two methods of treatment directly. “Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement (FAI)” by Larson and Giveans in 2009, and “Treatment of femoroacetabular impingement: Preliminary results of labral refixation” by Espinosa et al in 2006 both demonstrated improved outcomes with the repair group compared to the debridement group.
Hip Labrum Tear Video
This video is also available on Dr. Carreira’s YouTube channel.
Photos of Acetabular Labrum Tear
What is the Labrum?
The labrum is a fibrocartilage ring that surrounds the rim of the joint socket aiding in shock absorption, joint lubrication, pressure distribution, and stability.
What is a Labral Tear?
The term labral tear includes a variety of forms of injury to the acetabular labrum. There is a lot published on the outcomes of labral tears without differentiating forms of injury. The analogy which Dr. Carreira likes to use in describing these forms of injury is that the labrum is similar to a rope at the dock of a boat. It may appear old, small, frayed, partially torn, or nearly completely torn, or a combination of these factors.
Labral Degeneration: Degenerative changes in the labrum are “wear and tear” changes that include damage to the substance of the tissue itself. Studies of the tissue itself demonstrate that the tissue fibers lose their orientation and their makeup changes in terms of the connections and type of collagen. The most important cause is age, but other factors such as traumatic injury, femoroacetabular impingement, laxity, and dysplasia may contribute.
Complexity of Tearing: A complex tear may consist of multiple cleavage planes of variable depth that extend perpendicular to the surface of the labrum.
Hypoplastic: The tissue may be small in size, including after stabilizing the damaged tissue. Once the tissue is smoothed out for repair, the amount of tissue can differ across patients. In revision surgeries, the amount of tissue that remained after the initial surgery may be important.
Labral Tears: Repair vs. Reconstruction
The role of repair versus reconstruction, depending on the form of tearing and injury, is an area of some debate among advanced hip arthroscopists. This debate is one of the main areas in which Dr. Carreira regularly makes academic contributions.
Moreover, the Multicenter Arthroscopy Study of the Hip is focusing efforts to gain additional information about these injuries to help determine the optimal form of treatment. Preserving labrum tissue is the main goal of treatment, but there are injuries in which the labrum is irreparable. The vast majority of patients in Dr. Carreira’s practice are treated with labrum repair.