1. Femoracetabular Impingement: In Theory and In Practice Tom Bradbury, MD Assistant Professor Emory Orthopaedics and Spine Center March 11, 2011

2. A delay in non-arthroplasty treatment options for the hip……. Hip pain in the young patient not as common Hip is “deeper” than knee, shoulder Hip is more constrained Hip capsule is very robust Precarious blood supply to the femoral head limited an interest in surgical exposure…a fear of iatrogenic avascular necrosis

3. What is the etiology of osteoarthritis of the hip?

4. “ 90% of adult cases of osteoarthritis are the result of a morphologic developmental abnormality ”…..not a intrinsic problem with articular cartilage -Murray, 1965 -Harris, 1986

5. “Structural Pediatric Residuals” Developmental Dysplasia Slipped Capital Femoral Epiphysis Legg-Calve-Perthes Disease Multiple Epiphyseal Dysplasia Spondyloepiphyseal Dysplasia

6. Radiography of Hips with FAI Normal joint space Subtle morphologic aberrations “Normal” to the untrained eye

7. 1991: “cervico-acetabular impingement” secondary to femoral neck malunion 1999: “pincer” type impingement after periacetabular osteotomy for dysplasia

8. Evolution of an Understanding Reinhold Ganz Anatomy Perfusion Osteotomy Dislocation Impingement

9. Ganz’s Observation “Overcorrection” of hip dysplasia with periacetabular osteotomy “Iatrogenic retroversion” Hip pain with flexion (Pincer type anterior impingement)

10. Normal Cam Pincer

11. Hip “History” Arthrosis Insidious onset Constant Ache Walking on level ground Nocturnal symptoms Pre-arthrosis Sudden onset Sharp, intermittent pain Pain primarily with torsional activities Pain with prolonged flexion

12. Hip Exam: Gait “Antalgic” – shortened stance phase secondary to pain “Trendelenberg” – contralateral hip drops during stance phase secondary to abductor dysfunction “Abductor Lurch” – torso sways over affected leg during stance phase secondary to abductor dysfunction

13. Hip Specific Tests Trendelenberg Test Log Roll Passive External Rotation in Extension “C” test Thomas Test Stinchfield Test Ober’s Test Anterior Impingement Test (FADDIR) Posterior Impingement Test DEXTRIT (aka McCarthy)- Dynamic External Rotatory Impingement Test DIRIT- Dynamic Internal Rotatory Impingement Test Scour Test Ober Abduction internal rotation FABER

14. Hypermobility Beighton’s Criteria for hypermobility (3 of 5) – Thumb to forearm – SF extension > 90 – Elbow hyperextension > 10 – Knee hyperextension > 10 – Palms to floor

15. Findings Drehmann’s Sign- Obligate abduction and external rotation with forward flexion of the hip Coxa Saltans Interna- Iliopsoas tendon over the ileopectineal eminence Coxa Saltans Externa- Iliotibial band over greater trochanter

16. Imaging of the Young Hip Start with plain films: 1.Supine AP Pelvis Centered Low with Legs internally rotated 15 degrees 2.Cross table lateral of the hip with the leg 15 internally rotated 15 degrees 3.Dunn 45 of the Hip

17. Technique: AP – Supine with legs 15 degrees internally rotated – Film-focus distance: 1.2 meters – Point of center: midway between ASIS & Pubis Cross Table Lateral – Leg 15 degrees internally rotated – Perpendicular to long axis of femoral neck

18. Technique Dunn 45 – Hip flexed 45 degree, abducted 20, in neutral rotation

20. “ Diagnosis can only be made from a technically sound and properly positioned AP radiograph of the pelvis” -Ganz

21. “Normal”

22. LEGS EXTERNALLY ROTATED

23. ROTATION?

24. MALROTATION

25. TILT? Distance from tip of coccyx to superior edge of symphasis? 1 – 3 cm Siebenrock et al. From Sacrococcygeal junction: Male = 47.3 mm Female = 32.3 mm

28. POINT OF CENTER? ASIS PUBIS

29. Normal Landmarks

30. Ilioischial Line Iliopectineal Line

31. Sourcil

32. Posterior Wall Anterior Wall

33. Physeal Scar

34. Hip Imaging Lingo Acetabular Depth Acetabular Extrusion Acetabular Inclination Femoral Head Coverage Acetabular Version Head Sphericity Head-Neck Offset Congruency

35. Acetabular Depth The relationship of the true floor of the acetabulum to the ilioischial line Extrusion Index

36. AE E/A+E Normal = 25% Extrusion Index

37. Cox Profunda -Floor of fossa medial to ilioischial line - Extrusion Index 0

38. Cox Profunda -Floor of fossa medial to ilioischial line - Extrusion Index 0

39. Acetabular Protrusio -Femoral head to ilioischial line -Negative Extrusion Index

40. Acetabular Inclination (Tonnis angle) Horizontal line between center of femoral heads Line connected the medial and lateral edge of the sourcil

41. Acetabular Inclination (Tonnis angle) Negative angle = overcoverage/pincer

42. Acetabular Inclination (Tonnis angle) High positive angle = dysplasia

43. Lateral Center Edge Angle (of Wiberg) Normal = 25 - 40

44. Sphericity Measured by containment of physeal scar with circle of femoral head

45. Acetabular Version Relationship of walls to one another Ischial spine within pelvis Relationship of posterior wall to center of femoral head

46. Dysplasia Low CE angle (< 25) Elevation of acetabular inclination Elevation of Extrusion index

47. Retroverted Acetabulum Cross over sign Ischial Spine within pelvis

48. False profile view AnteriorPosterior

49. Aspherical head Physeal Scar extends beyond the circle

50. Femoral Cam Alpha angle > 50

54. Dunn 45