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

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

Overview of Hip Impingement Concept first presented in 1936 – Sporadic mention Ganz et. Al 2001-2003 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

Warwick Agreement PURPOSE: International and Multidisciplinary agreement on the diagnosis and treatment of FAI Open Meeting – Sports Hip Conference (June 27-28, 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

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?

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

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

Suggested Terminology

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

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

How should FAI be diagnosed? Symptoms, clinical signs, and imaging findings must be present Level of agreement 9.8/10 (95% CI 9.6-10) 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

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

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

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

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

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

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

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

Open vs. Surgical Correction of CAM Deformity

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

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)

Prognosis for FAI? Cam morphology is associated with hip osteoarthritis. OR range from 2.2-20 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).

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?

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

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

Future Directions

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.