Hip Labral Tears Flashcards
Disorders of the hip labrum is an umbrella term that includes…
any issues involving that labrum such as femoroacetabular impingement (aka FAI) and acetabular labral tear (ALT). This mechanically induced pathology is thought to result from excessive forces at the hip joint. For example, a tear could decrease the acetabular contact area and increase stress, which would result in articular damage, and destabilize the hip joint.
Amber and Mohan (2018) proposed that the term “fissure” is a better alternative to labral tears, at least in patients over the age of 40, in order to prevent overdiagnosis and unnecessary medical intervention
Clinically Relevant Anatomy
The hip (acetabulofemoral joint) is a synovial joint formed between the femur and acetabulum of the pelvis. The head of the femur is covered by Type II collagen (hyaline cartilage) and proteoglycan. The acetabulum is the concave portion of the ball and socket joint. The acetabulum has a ring of fibrocartilage called the labrum that deepens the acetabulum and improves stability of the hip joint
Epidemiology/Aetiology
The labrum of the hip is susceptible to traumatic injury from the shearing forces that occur with twisting, pivoting and falling. Direct trauma (e.g. motor vehicle collision) is a known cause of acetabular labral tearing.
Additional causes include acetabular impingement, joint degeneration and childhood disorders such as Legg-Calve-Perthes disease, congenital hip dysplasia and slipped capital femoral epiphysis.
While most tears occur in the anteriosuperior quadrant, a higher than normal incidence of posterosuperior tears appear in the Asian population due to a higher tendency toward hyperflexion or squatting motions.
The most common mechanism is an external rotation force in a hyperextended position. Microtrauma is believed to be responsible for labral lesions in cases where pain develops gradually.
According to a systematic review by Leiboid et al (2008), some factors concerning etiology:
Hip labral tears commonly occur between 8 to 72 years of age and on average during the fourth decade of life
Women are more likely to suffer than men
22-55% of patients that present with symptoms of hip or groin pain are found to have an acetabular labral tear
Up to 74.1% of hip labral tears cannot be attributed to a specific event or cause
Hyperabduction, twisting, falling or a direct blow from a car accident were common mechanisms of injury in patients who identified a specific mechanism of injury
Women, runners, professional athletes, participants in sports that require frequent external rotation and/or hyperextension are at increased risk of a hip labral tear.
Those attending the gym three times a week have an increased risk of developing a hip labral tear
Mechanism of Injury
There are five common mechanisms of labral tears that are widely recognized:
Femoroacetabular impingement (FAI) Trauma: This can occur due to a shearing force associated with twisting or falling, mis-stepping on uneven ground or colliding with bicycles or vehicles.
Repetitive hip hyperextension and external rotation (e.g. during terminal stance in running) can create stress at the chondrolabral junction (typically the 10-12 o’clock position) resulting in microtrauma and eventual labral injury.[11] It may also be associated with iliopsoas impingement resulting in labral injury at the 3 o’clock position.
Capsular Laxity: This is thought to occur in one of two ways; cartilage disorders (e.g. Ehlers-Danlos syndrome) or rotational laxity resulting from excessive external rotation. These forces are often seen in certain sports including ballet, hockey and gymnastics.
Hip Dysplasia: Certain abnormalities of the femur.
acetabulum or both (e.g. shallow acetabulum, femoral or acetabular anteversion, decreased head offset or perpendicular distance from the center of the femoral head to the axis of the femoral shaft) can lead to inadequate containment of the femoral head within the acetabulum, placing increased stress into the anterior portion of the hip joint resulting in impingement and possible tears over time.
Degeneration
Classification
Labral tears can be classified in different ways.
Etiology
Location:
Anterior tear The pain will generally be more consistent and is situated on the anterior hip (anterosuperior quadrant) or at the groin. They frequently occur in individuals in European countries and the United States.
Posterior Are situated in the lateral region or deep in the posterior buttocks. They occur less frequently in individuals in European countries and the United States, but are more common in individuals from Japan
Morphology:
Radial flap most common, disruption of free margin of the labrum
Radial fibrillated fraying of the free margin, associated with degenerative joint disease
Longitudinal peripheral least common
Unstable / Abnormally mobile can result from a detached labrum
Characteristics/Clinical Presentation
There is some variation in the presentation of hip labral tears. Patients frequently present with anterior hip and groin pain, although less common areas of pain include anterior thigh pain, lateral thigh pain, buttock pain and radiating knee pain.[
The majority of patients (90%) diagnosed with acetabular labral tears have had complaints of pain in the anterior hip or groin. This can be an indication for an anterior labral tear, whereas buttock pain is more consistent with posterior tears and less common.
Mechanical symptoms associated with a tear are clicking, locking, popping, giving way, catching and stiffness. The significance of these signs is questionable.
Patients often describe a dull ache which increases with activities such as running, brisk walking, twisting movements of the hip or climbing stairs. These specific manoeuvres may cause pain in the groin; 1) Flexion, adduction, and internal rotation of the hip joint are related to anterior superior tears and 2) Passive hyperextension, abduction, and external rotation are related to posterior tears.
Functional limitations may include prolonged sitting, walking, climbing stairs, running, and twisting/pivoting.The symptoms can have a long duration, with an average of greater than two years.
The patient may report experiencing an audible pop or a sensation of subluxation at the time of the trauma, if there was a specific traumatic onset.
Differential Diagnosis
Schmerl et al (2005) provide a thorough list for differential diagnosis of labral injury causing hip pain
Contusion (especially over bony prominences) Strains Athletic pubalgia Osteitis pubis Inflammatory arthridites Piriformis syndrome Snapping hip syndrome Bursitis (trochanteric, ischiogluteal, iliopsoas) Osteoarthritis of femoral head Avascular necrosis of femoral head Septic arthritis Fracture or dislocation Tumors (malignant and benign) Hernia (inguinal or femoral) Slipped capital femoral epiphysis Legg-Calve-Perthes disease Referred pain from lumbosacral or sacroiliac regions
