Anatomy
The hip joint consists of the acetabulum and the femoral head (caput femoris). Around the edge of the joint there is a labrum that stabilises the hip joint and is similar to the meniscus in the knee and labrum in the shoulder.
Cause
Like articular cartilage, the labrum is exposed to mechanical stress, which with age causes gradual degeneration. Degeneration is accelerated in people with hip injuries and results in osteoarthritis of the hip joint. Changes in the labrum are often asymptomatic. 60% of all healthy athletes have changes that on ultrasound or MRI scans of the hip look like labral damage.
Therefore, labrum injuries only require treatment if the symptoms can be attributed to the changes detected. Expansion of the bone at the acetabular rim or femoral head/neck (caput/collum) can pinch the labrum and articular cartilage during hip movements (Pincer and CAM impingement respectively), causing damage to the labrum and articular cartilage.
Osteoarthritis, hip fractures, congenital hip dysplasia and a single heavy overload can result in a labrum injury.
Symptoms
The pain is often related to physical activity, especially hip flexion, such as squats, cycling or kicking. Often there will be restriction of movement when rotating the hip joint. In severe cases, there may be rest pain.
Examination
There is impaired mobility rotation in the hip joint. The two most commonly used tests FABERE and FADIR are sensitive but non-specific (i.e. they are positive for several different disorders in and around the hip joint). It will often be necessary to supplement the standard clinical examination with an MRI scan (which finds most labrum injuries) or ultrasound scan.
Labrum injuries are seen in 22-55% of people with hip pain, but unless there are cysts in the labrum, changes are of uncertain significance (Berthelot JM, et al. 2023).
Treatment
As most labrum injuries diagnosed by ultrasound and MRI scans are incidental and insignificant findings, treatment should only be initiated if the symptoms correspond to a labrum injury. A labrum injury is generally a consequence of an underlying pathology in the hip joint that should be treated. Usually, treatment follows the usual guidelines, with relief from pain-inducing activity, stretching and graduated rehabilitation within the pain threshold.
If relief and rehabilitation are not successful, treatment may be supplemented with medical treatment in the form of arthritis pills (NSAIDs) or by ultrasound-guided injection of adrenal cortex hormone to remove any inflammation. Surgical treatment can be attempted with removal of any bony deposits (Pincer and CAM) and possibly removal of the labrum. In some cases, injuries to the labrum can be sutured to preserve the labrum.
Scientific evidence for the treatment effect of joint lip injuries is scarce (Savoye-Laurens T, et al. 2023).
Complications
If no progress is made, you need to consider whether the diagnosis is correct or due to another injury in the hip joint, e.g:
In particular, the following should be considered:
