II. Definitions
- Femoroacetabular Impingement (FAI)
- Abutment of the acetabular rim against the proximal femur
III. Epidemiology
- Common cause of Hip Pain
- Earlier presentations in athletes than non-athletes
- Athletes often present with less bony changes on plain film imaging than non-athletes
- More common presentations in athletes requiring hip hyperflexion and wide range of motion
IV. Types
- Cam Deformity
- Bony overgrowth of femoral neck or femoral head
- Pincer Deformity
- Overgrowth of the acetabulum
V. Symptoms
- Gradual onset without history of specific injury
- Anterolateral Hip Pain
- Sharp pain
- Gradual progression
- Limits both sport activities as well as simple Activities of Daily Living
- C-Sign used by patients to demonstrate the area of pain (esp. with labral tear)
- Patient cups the area of pain between their thumb and index finger
- C-Shape: One finger on anterior hip and the other on posterior hip (below the inguinal ligament)
- Provocative maneuvers
- Hip flexion and Hip Rotation
- Deep Squat
- Turning or pivoting toward the affected side
- Prolonged sitting
- Rising from a chair or getting in or out of a car
- Forward flexion
VI. Signs
- See Hip Exam
- FADIR Test (specific for Hip Impingement)
VII. Imaging: XRay
- Anteroposterior Hip
- Hip Osteoarthritis
- Acetabulum dysplasia
- Osteonecrosis of femoral head
- Sacroiliac joint Osteoarthritis
- Lumbar Spine disorders
- Standing Anteroposterior Hip
- Best identifies Pincer Deformity
- Dunn View (hip flexed to 90 degrees and abducted 20 degrees)
- Anterior femoral neck Cam lesion (exostosis predisposing to FAI by impinging labrum against acetabulum)
- Anterior femoral neck osteophytes
VIII. Imaging: Advanced
- MRI hip with arthrography (contrast)
- Evaluates the hip labrum with Test Sensitivity >90% (<30% without arthrography)
- Diagnostic bupivicaine (Marcaine) injection at the time of arthrography can assist diagnosis
- Patient keeps diary of pain level following injection
- Improvement in pain following injection suggests intraarticular cause of pain
IX. Differential Diagnosis
- See Hip Pain Causes
X. Management
- Physical Therapy
- Goal to improve hip Muscle flexibility and strength
- Orthopedic referral
- Hip Pain refractory to conservative measures
- Arthroscopy
- Goal to reduce impingement and Osteoarthritis risk, and to repair or remove injured tissue
- Most beneficial in hip locking, catching or popping or for sharp Hip Pain
XI. Complications
XII. References
- Schleihauf (2019) Crit Dec Emerg Med 33(5): 19-28
- Beck (2005) J Bone Joint Surg Br 87(7): 1012-18 [PubMed]
- Ganz (2003) Clin Orthop Relat Res 417:112-20 [PubMed]
- Kuhlman (2009) Am Fam Physician 80(12): 1429-40 [PubMed]