The causes of labral tears includes trauma, femoroacetabular impingement (FAI), capsular laxity/hip hypermobility, dysplasia, and degeneration.
Labral tears can be classified by their location, morphology or cause. With respect to location, tears are classified as anterior, posterior, or superior/lateral.
Most tears occurred in the anterior portion of the labrum however, in Japan the majority of tears occur in the posterior aspect of the labrum, likely due to the frequent practice in Japan of squatting or sitting on the ground or floor. Posterior tears in the Western world occur mainly with discrete episodes of trauma, when a load impacts the femur, driving the femoral head posterior, transferring shear and compressive forces to the posterior labrum.
Labral tears can be classified morphologically as: radial flap, radial fibrillated, longitudinal peripheral, and unstable. Radial flap tears and radial fibrillated tears involve the free margins of the labrum and are the most commonly encountered. Longitudinal peripheral tears of various lengths are seen at the acetabulum–labrum junction, whereas unstable tears follow no real pattern but cause mechanical symptom
Although unusual, isolated traumatic tears of the labrum do occur. These are often a result of significant trauma to the hip joint during contact sports or trauma resulting in either subluxation or dislocation of the femoral head. These traumatic labral tears are often associated with chondral injuries to the femoral head and/or acetabular rim injury. Damage to the acetabular labrum has been reported as a cause of irreducible dislocation or recurrent dislocation after traumatic dislocation of the hip. Posterior hip dislocations produce posterior labrum tears.
Labral tears may be diagnosed in both sexes and throughout all ages. Most studies report that symptomatic labral tears occur more frequently in women than in men This may partly be due to the increased incidence of hip dysplasia in women, especially in the age range of 15–41 years.
More than 90% of patients diagnosed with acetabular labral tears complain of anterior hip or groin pain Pain is less often reported in the lateral region or deep in the posterior buttocks and pain may radiate to the knee. Burnett and colleagues studied 66 patients found to have labral tears by arthroscopy and reported 92% had predominant localized groin pain, 52% had associated anterior thigh pain, 59% described lateral hip pain, and 38% reported associated buttock pain, while no patient presented with isolated buttock pain. Unique in women is the possible concomitant pelvic-floor pain that may occur Data suggest that anterior hip or groin pain is more consistent with an anterior labral tear, whereas buttock pain is more consistent with a posterior labral tear.
Patients with a labral tear also report a variety of mechanical symptoms, including clicking, locking or catching, or giving way. Of these symptoms, clicking appears to be the most consistent clinical symptom. In addition, a labral tear can also contribute to hip instability.
The onset of symptoms was described as insidious in 61% of patients. Many patients with labral tears describe a constant dull pain with intermittent episodes of sharp pain that worsens with activity. Walking, pivoting, prolonged sitting, and impact activities, such as running, often aggravate symptoms. Seventy-one percent of patients describe night pain . Functional limitations include, limping (89%), needing a banister to climb stairs (67%), limitation of walking distance (46%), and sitting limited to 30 min (25%)
The most consistent physical exam finding in patients with acetabular labral tears is a positive anterior hip-impingement test. This is performed with the patient supine with the hip and knee at 90° of flexion. The hip is internally rotated while an adduction force is applied. A positive test results in pain provocation in the anterolateral hip or groin.
Robertson et al. performed a systematic review to determine the rate of patient satisfaction that can be expected following acetabular labral debridement. Literature between January 1980 and September 2005 that included patients with symptomatic acetabular labral tears who failed conservative management, were not claiming workers’ compensation, and did not have severe arthritis or severe acetabular dysplasia, and had at least 2 years follow-up, was analyzed. Their conclusions were as follows: at least 67% and as high as 91% of patients will be satisfied with their outcome at 3.5 years, there were good results by a modified Harris Hip Score in patients who are subjectively satisfied with their outcome and a complete resolution of mechanical symptoms was seen in nearly 50% of patients with this complaint with as high as 90% having some reduction in the frequency of these symptom