Acetabular labrum tears
From Medical-Wiki
Contents |
Anatomy
There is a fibrocartilaginous rim that attaches to the acetabulum, the labrum. It is comprised of dense collagenous tissue and is triangular in shape. This structure is surrounded by a double layered synovial membrane that winds its way around the joint.
The labrum functions to deepen the cavity of the hip joint. It also protects bone and has an effect of reducing surface irregularities. Another function of the labrum is a “sealing effect.” If the labrum is removed, the frictional forces between the femoral and acetabular surfaces are increased by as much as 92%. The center of contact also shifts to the rim.
Differential diagnosis
The differential diagnosis for a labral tear is identical to that for groin pain. It should be noted that labral tears are relatively uncommon. [1]
Clinical presentation
Patients with tears may present with complaints of locking, clicking or a catching sensation in addition to pain. There may also be a decrease in range of motion. [2]
Diagnosis
Radiological findings
When evaluating the possibility of a tear, conventional MR is not as sensitive as a combination of MR arthrography and a small field of view. [3] Ultrasound alone does not visualize labral tears on a consistent basis. Its effectiveness is increased if dye is injected into the joint. [4]
Treatment
The diagnosis and repair of labral tears has become defined only within the past few years. Prior to that, clicking and popping were often attributed to a snapping of the iliotibial band. When labral tears were first defined, surgical debridement of the labrum was attempted through an open approach. Quite often, this required the dislocation of the hip with a predictable increase in operative morbidity. In the late 1990s, an arthroscopic approach was initiated that has proved to be far more effective and carry a far lower pattern of morbidity.
However, the diagnosis of an acetabular labral tear is still difficult to make. When a hip joint is without evidence of arthritic changes, surgical debridement has a high success rate. When arthritis is present, outcomes are not nearly as positive. [5]
