Hip Impingement

Aka: Hip Impingement, Femoroacetabular Impingement, FAI

1. See Also
   1. Hip Pain
2. Definition
   1. Abutment of the acetabular rim against the proximal femur
3. Epidemiology
   1. Common cause of Hip Pain
4. Symptoms
   1. Anterolateral Hip Pain
      1. Sharp pain
      2. Gradual progression
      3. Limits both sport activities as well as simple Activities of Daily Living
      4. C-Sign used by patients to demonstrate the area of pain
         1. Patient cups the area of pain between their thumb and index finger
         2. C-Shape: One finger on anterior hip and the other on posterior hip (below the inguinal ligament)
   2. Provocative maneuvers
      1. Hip flexion and Hip Rotation
      2. Turning or pivoting toward the affected side
      3. Prolonged sitting
      4. Rising from a chair or getting in or out of a car
      5. Forward flexion
5. Signs
   1. See Hip Exam
   2. FADIR Test (specific for Hip Impingement)
6. Imaging: XRay
   1. Anteroposterior Hip
      1. Hip Osteoarthritis
      2. Acetabulum dysplasia
      3. Osteonecrosis of femoral head
      4. Sacroiliac joint Osteoarthritis
      5. Lumbar spine disorders
   2. Dunn View (hip flexed to 90 degrees and abducted 20 degrees)
      1. Anterior femoral neck Cam lesion (exostosis predisposing to FAI by impinging labrum against acetabulum)
      2. Anterior femoral neck osteophytes
7. Imaging: Advanced
   1. MRI hip with arthrography (contrast)
      1. Evaluates the hip labrum with Test Sensitivity >90% (<30% without arthrography)
      2. Diagnostic Bupivicaine (Marcaine) injection at the time of arthrography can assist diagnosis
         1. Patient keeps diary of pain level following injection
         2. Improvement in pain following injection suggests intraarticular cause of pain
8. Differential Diagnosis
   1. Hip Pain
9. Management
   1. Physical Therapy
      1. Goal to improve hip muscle flexibility and strength
   2. Orthopedic referral
      1. Hip Pain refractory to conservative measures
      2. Arthroscopy
         1. Goal to reduce impingement and Osteoarthritis risk, and to repair or remove injured tissue
         2. Most beneficial in hip locking, catching or popping or for sharp Hip Pain
10. Complications
    1. Hip labral tear
    2. Hip Osteoarthritis
11. References
    1. Beck (2005) J Bone Joint Surg Br 87(7): 1012-18
    2. Ganz (2003) Clin Orthop Relat Res 417:112-20
    3. Kuhlman (2009) Am Fam Physician 80(12): 1429-40