Femoroacetabular impingement and hip labral tear
Femoroacetabular impingement is abnormal contact of the femoral head-neck junction against the acetabular rim that causes insidious groin pain in young, active adults and damages the acetabular labrum, producing painful clicking, catching, and locking. Diagnosis rests on anterior hip pain with a positive FADIR test, confirmed by MR arthrography after plain radiographs; treatment begins with physical therapy and activity modification, with arthroscopic surgery for failure of conservative care.
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What this article covers
- Overview
Definition: femoroacetabular impingement (FAI) is abnormal contact of the femoral head-neck junction against the acetabular rim during hip motion, occurring with a normal range of motion and associated with an aspherical femoral head.
- Epidemiology
One of the most common causes of anterior hip pain in athletes, alongside sports hernia (athletic pubalgia), adductor strain or tear, and inguinal hernia.
- Risk factors
Structural hip abnormalities: an aspherical femoral head and abnormal head-neck contact with the acetabular rim are the defining substrate for FAI and for secondary labral damage.
- Pathophysiology
Abnormal bony contact starts the process: with hip flexion and rotation, the femoral head-neck junction abuts the acetabular rim instead of clearing it, producing pain at the extremes of motion.
- Clinical features
Insidious anterior hip or groin pain in a young, active patient is the hallmark, worse with activity and especially with sprinting or jumping.
- Differential diagnosis
Septic arthritis of the hip: acute-onset anterior hip pain with fever and inability to bear weight, requiring hip aspiration; see septic-arthritis.
- Diagnosis
FAI and labral tear are confirmed by imaging after a suggestive clinical picture: insidious groin pain in a young, active patient with a positive FADIR test raises the diagnosis, and MR arthrography…
- Management
First, start physical therapy focused on hip muscle strengthening, together with activity modification that removes sprinting, jumping, and the deep flexion and rotation that reproduce the pain; this…
- Complications
Hip osteoarthritis: FAI is a recognized risk factor for incident osteoarthritis, and the associated structural disorders (prior slipped capital femoral epiphysis, dysplasia) also predispose to premature osteoarthritis.
- Prognosis
Conservative care is the starting point for every patient: physical therapy and activity modification are initial treatment, and surgery is reserved for failure of these measures.
- Prevention
Detect hip dysplasia in infancy: examine for instability with the Barlow and Ortolani maneuvers, and image at-risk infants with normal or equivocal findings by hip ultrasound up to age 4 months and…
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