1. Hip Update 2017 – Femoroacetabular Impingement (FAI)
May 26, 2017
Daniel Abourbih, PGY4
Sports and Exercise Medicine Fellow – McMaster University
Emergency Medicine Resident – University of Toronto

2. Presentation Outline History Hip Impingement Warwick Agreement
Consensus Questions
Diagnostic terminology
Clinical features
Imaging strategies
Treatment options
Prevention
Management of asymptomatic

3. Overview of Hip Impingement
Concept first presented in 1936 – Sporadic mention
Ganz et. Al
Proposed link between FAI and OA
New surgical approach for improvement of Fem/Acetabular clearance
365% increase in Hip Arthroscopy over a 6 year period (1)
Multiple Controversies
Exact definition
Prevention and Treatment Strategies
Risk factor for OA development
Health care economics concerns:
New diagnosis
Ambiguity of diagnostic criteria
Costs and benefits of treatment uncertain

4. Warwick Agreement
PURPOSE: International and Multidisciplinary agreement on the diagnosis and treatment of FAI
Open Meeting – Sports Hip Conference (June , 2016)
Proposed questions presented and evidence provided
Consensus Panel of Practitioners involved in FAI Management (June 29, 2016)
Sports and Exercise Medicine Physicians
Physiotherapists
Orthopedic Surgeons
Radiologists
22 Clinicians/Academics, 1 patient
9 countries
5 specialties represented

5. Consensus Questions What is FAI Syndrome?
How should FAI Syndrome be diagnosed?
Appropriate Imaging Modalities?
What is the appropriate treatment for FAI Syndrome?
What is the prognosis for FAI Syndrome?
How should asymptomatic individuals with CAM or Pincer Morphology be managed?

6. Agreement Meeting June 29, 2016 Panel vote on each proposal
Likert Scale 0-10
0 – Complete Disagreement
5 – Neither Agreement or Disagreement
10 – Complete Agreement
Discussions continued until:
Mean score >7.5
Chairman deemed no further compromise possible

7. What is FAI Syndrome?
A motion-related clinical disorder of the hip with a triad of symptoms, clinical signs and imaging findings
Symptomatic premature contact between the proximal femur and the acetabulum
Level of agreement: mean score 9.8 (95% CI 9.6 to 10)
KEY Feature of Definition = Must be symptomatic
Hip Radiographic morphology without symptoms NOT included
Prior definitions included (2):
Abnormal morphology of Femoral Head and Acetabulum
Abnormal contact between above structures
Supraphysiological motion causing abnormal contact
Repetitive contact causing injury

8. Suggested Terminology

9. CAM Morphology Bony overgrowth at Femoral Head/Neck Junction
Results in Non-spherical CAM shaped morphology
CAM impingement – Femoro- Acetabular contact in Flexion/Internal Rotation
Associated with Antero-Superior Labral and Chondral Damage
Described by Alpha Angle
Quantifies the extent to which the femoral head deviates from spherical
Normal <55-60 deg
Other: Pistol Grip Deformity
Found in 15-25% of Population

10. Pincer Morphology
Pathological contact between the acetabular labrum and rim and the femoral head-neck junction – Essentially Acetabular Overcoverage
Labral Injury, Less Chondral Injury
May result in Labral Ossification worsening overcoverage
Associated with:
Acetabular Retroversion
Coxa Profunda
Protrusio Acetabuli

12. How should FAI be diagnosed?
Symptoms, clinical signs, and imaging findings must be present
Level of agreement 9.8/10 (95% CI )
Primary Symptoms of FAI
Motion-related Hip/Buttock pain – “C-sign”
Pain can also be felt in back, thigh, and knee
Mechanical symptoms – Clicking, catching, locking, stiffness, giving way
Presenting Symptoms Vary
Some experience with Vigorous Activity – Ex. Football
Onset with supraphysiologic motion – Ex. Dance, Gymnastics
Present at rest – Ex. Prolonged sitting

13. Clinical Signs required?
Diagnosis does not depend on single clinical sign
Significant heterogeneity in performance and interpretation of PE maneuvers
Studied in populations with high Pre-test Probability
Hip Impingement test generally reproduce patient’s symptomatology (3)
FADIR – Sensitive but not specific (High False Positive Rate)
Sensitivty 94-99%
Specificity 9-23%
Typically restricted internal rotation
Suggested Physical Exam should include:
Gait, single leg control
Muscle tenderness around hip
Hip ROM – Internal and External rotation
Special tests – FABER, FADIR, Log Roll

14. Role of Image-guided injection in Diagnosis?
Multiple potential soft-tissue confounders to diagnosis
Lumbosacral spine, Iliopsoas/Adductor Strains, GT Bursae, Gluteal Ensethopathy, Piriformis Syndrome
Authors do advocate the use to Image-guided IA local anesthetic injections – Fluro or U/S guided (4)
Has been shown to differentiate intra-articular from Extra-articular pathologies

15. Imaging for FAI Syndrome?
AP Pelvis and Lateral Femoral Neck View
AP pelvis – Centered on Pubic Symphysis, Limit rotation and pelvic tilt
Lateral view – Cross-table lateral, Dunn and frog lateral
CAM – Flattening or convexity at the Femoral Head/Neck junction
Pincer – Global or focal femoral head over coverage by the acetabulum

16. Advanced Imaging? Limitations of Plain Radiographs
Low sensitivity for morphology detection
Ex. CAM alpha angles – Poor sensitivity discriminating Symptomatic and Assymptomatic (6)
Recommend Cross-sectional Imaging
Further assessment of morphology, 3D reconstruction
MRI Arthrogram suggested - Associated cartilage or labral injury
Assessment of other possible Hip/Groin soft tissue causes of pain
Always correlate with clinical symptoms
Assymptomatic Labral Tears
Assymptomatic CAM/Pincer Morphologies

17. Treatment for FAI Syndrome?
Can be treated by Conservative care, Rehabilitation, or Surgery
Conservative treatment – Education, Watchful waiting, or lifestyle and activity modification
Rehabilitation – Improve hip stability, neuromuscular control, strength, ROM, and movement patterns
Surgery – Open or arthroscopic, repair soft-tissue damage and correct FAI morphology
Level of agreement: mean score 9.5 (95% CI 9.0 to 10)
Emphasized Shared decision options – Practically, a trial of conservative and rehabilitation prior to surgical options

18. Rehabilitation Protocol?
Heterogenous Interventions suggested
Taping/Positioning
Gluteal/Abdominal strengthening
Hip flexor strengthening
Core strengthening
No High Quality RCT data available
GRADE Quality of Evidence: Low to Very Low

19. Hip Arthroscopy Primary Surgical corrective technique
Treatment of Labral and Chondral injuries in the central compartment by traction
Allows Femoral/Acetabular bony correction
Inadequate/Inappropriate bone correction – Most common cause of treatment failure
Overcorrection – Risk of Femoral Neck #, Loss of Hip fluid seal
Overall complication rates low (<4%)
Lat Fem Cutaneous nerve
Pudendal nerve
Iatrogenic labral/chondral damage

20. Open vs. Surgical Correction of CAM Deformity

21. Open Surgical Hip Dislocation?
May be more ideal treatment for severe/complex FAI Deformities
CAM Lesions with Posterior Extension
Severe Global Acetabular Overcoverage
Extra-articular impingement
Relatively low rates of complication
Trochanteric Non-union 1.8%
Longer recovery times documented

22. Surgical Outcomes? Rate of Return to Sport = 87% (56-100%)
Casartelli NC, et al. Br J Sports Med 2015;49:819– 824
Systematic review of 1076 Hips
Equal distribution of M:F, High level to Recreational Athletes
73% Arthroscopic, 21% Open Approach
Femoral Osteoplasty 90%, Acetabular Rim Trimming 51%
Labral Tear Treatment
38% repaired
35% debrided
6% Partialy resected
Acetabular and Femoral Cartilage treatment
Rehabilitation Protocols
Level IV – Low level Evidence (Case Series)
Rate of Return to Sport = 87% (56-100%)
Rate of Return to SAME level = 82% (55-100)

23. Prognosis for FAI?
Cam morphology is associated with hip osteoarthritis.
OR range from
OA risk may depend on degree
Moderate Alpha >60 deg – OR 2.5
Severe Alpha > 83 deg – OR 9
Pincer Morphology less closely related
It is currently unknown whether treatment for FAI syndrome prevents hip osteoarthritis.
Level of agreement: mean score 9.6 (95% CI 9.3 to 9.8).

24. Asymptomatic CAM/Pincer Morphology
Environmental Causes
Suggested 2nd to excessive Hip Loading
89% Prevalence in Skeletal Mature Bball
50% in Symptomatic Soccer Players
Only 9% found in cohort of pre-pubescent males
?Physeal Damage or Physiological Adaptation to Stress
Should we limit/alter the activity of Adolescents demonstrating CAM morphology?

25. Asymptomatic CAM/Pincer Morphology
Many patient with radiographic evidence WON’T develop OA
PPV = 6-25%
NPV = 98-99%
Other Factors at play
Level of activity
Degree of impingement
Obesity/Trauma/Classical OA risk factors
Current Recommendations
No role for Preventative Surgery
Preventative Physio-Led rehabilitation suggested

26. Summery of Recommendations
FAI Syndrome is clinical triad of symptoms, signs, and radiographic features
Xrays/Crossectional Imaging and Image-guided injections are a key component in diagnosis
Lifestyle modification, Physiotherapy, and other conservative measures form the backbone of basic treatment
Arthroscopic repair has supplanted open techniques for most repairs
CAM morphology associated with OA but unable to predict which individuals are truly at risk

27. Future Directions

28. References
Montgomery SR, Ngo SS, Hobson T, et al. Trends and demographics in hip arthroscopy in the United States. Arthroscopy 2013;29:661–5
Sankar WN, Nevitt M, Parvizi J, et al. Femoroacetabular impingement: defining the condition and its role in the pathophysiology of osteoarthritis. J Am Acad Orthop Surg 2013;21(Suppl 1):S7–S15
Kivlan BR, Martin RL, Sekiya JK. Response to diagnostic injection in patients with femoroacetabular impingement, labral tears, chondral lesions, and extra-articular pathology. Arthroscopy 2011;27:619–27
Reiman MP, Goode AP, Cook CE, et al. Diagnostic accuracy of clinical tests for the diagnosis of hip femoroacetabular impingement/labral tear: a systematic review with meta-analysis. Br J Sports Med 2015;49:811.
Sutter R, Dietrich TJ, Zingg PO, et al. How useful is the alpha angle for discriminating between symptomatic patients with cam-type femoroacetabular impingement and asymptomatic volunteers? Radiology 2012;264:514–21.
Wall PD, Fernandez M, Griffin DR, et al. Nonoperative treatment for femoroacetabular impingement: a systematic review of the literature. PM R 2013;5:418–26.