Hip Labral Tear

The acetabular labrum seals the central hip joint from the periphery, keeps the synovial fluid within the central compartment, and creates a negative pressure within the joint. The negative pressure helps to resist subluxation of the femoral head and increases stability. Any disruption of the labrum can negatively affect articular cartilage health and joint stability.^{[citation needed]}

There are two general mechanisms of injury to the acetabular labrum.

1. A single event of significant trauma. This normally involves forced resistance of hip flexion while kicking or running (for example in Rugby).
2. Repetititve injury and microtrauma in an osteoarthritic, dysplastic hip or in a hip with FAI.

Clinical Features

The most common symptom is groin pain that is exacerbated by athletic activity. This can occur in particular with activities involving aggressive hip flexion such as jumping or sprinting. Pain can sometimes occur when fatigued such as during a long distance run, or running up hill. Some patients may report groin pain with sitting, transitioning between standing from sitting, or when descending stairs. Some activities of daily living may be affected such as putting on shoes or stockings while sitting.

Examination features are pain with hip flexion and anterior impingement tests. No test is specific for labral injury, and signs and symptoms overlap with FAI. Some useful tests are repeated hip flexion, hip flexion against resistance, and FADDIR testing.

Imaging

MR imaging is often required to make a diagnosis, and this is the most accurate imaging modality. Xrays can be helpful, and should include standing anteroposterior, cross-table lateral or Dunn lateral, and a false profile view. An intraarticular injection of local anaesthetic with or without a glucocorticoid can aid in the diagnostic process if pain is ablated following injection. If an MRA is performed then anaesthetic can be injected along with the contrast and a pain diary can be ascertained.

Management

An initial trial of non-operative management is recommended. Healing of the labrum has been demonstrated in animal studies. Physical therapy is the mainstay of conservative management. Strengthening of the pelvic girdle can aid in stabilising the hip joint, correct abnormal pelvic tilt, and rectify abnormal load on the labrum.

Arthroscopic surgery can be considered upon failure of conservative management. Where possible the labrum should be restored rather than excised in order to restore normal hip joint function.