lower force levels, especially when the force is applied repeatedly. The critical threshold for injury to these tissues is not yet understood (48).

The presence of a cam lesion alone does not predict injury, as there are many examples of bilateral pathology but only one symptomatic hip. It is therefore unclear at what point this continuum of injury progresses beyond a recoverable joint. We know that the presence of a large cam lesion creates an at- risk hip, but a number of factors, such as size of cam, previous injury, duration of symptoms, level of activity and resilience of the patient’s cartilage, must be considered. Further research is required to determine the prevalence and natural history of asymptomatic cam lesions and the relative contribution of these variables to the development of intra-articular hip damage (49). Over the next few years, due to

the inability of the human body to attenuate the forces directed through the hip joint, the number of cases of FAI secondary to trauma, repetitive microtrauma and instability is likely to increase significantly.

References 1. Myers SR, Eijer H, Ganz R. Anterior femoroacetabular impingement after periacetabular osteotomy. Clinical Orthopaedics and Related Research 1999;363:93–99 2. Beaulé PE, Edward Zaragoza, Kambiz Motamedi, Nathan Copelan, Frederick J. Dorey - Three-dimensional computed tomography of the hip in the assessment of femoroacetabular impingement - Journal of Orthopaedic Research - Volume 23 Issue 6, Pages 1286 - 1292 3. Beaule P. Course notes: sports hip surgery, 2008 4. Petersen W, Petersen F, Tillmann B. Structure and vascularization of the acetabular labrum with regard to the pathogenesis and healing of labral lesions. Archives of Orthopaedic and Trauma Surgery 2003;123:283–288 5. Byrd JWT. Arthroscopy. Journal of Arthroscopic and Related Surgery 2006;22:1260–1262 6. Aydingoz U, Ozturk. MR imaging of the acetabular labrum: a comparative study of both hips in 180 asymptomatic volunteers. European Radiology 2001;11:567–574 7. Tan V, Seldes RM, Katz MA, Freedhand AM, et al. Contribution of acetabular labrum to articulating surface area and femoral head coverage in adult hip joints: an anatomic study in cadavera. American Journal of Orthopedics 2001;30:809–812

14

PREDISPOSES THE HIP TO INTRA-ARTICULAR PATHOLOGY

8. Ferguson SJ, Bryant JT, Ganz R, Ito K. The influence of the acetabular labrum on hip joint cartilage consolidation: a poroelastic finite element model. Journal of Biomechanics 2000;33:953–960 9. Czerny C, Kramer J, Neuhold A, Urban M, et al. MR imaging and MR arthrography of the acetabular labrum: comparison with surgical findings. Fortschritte auf dem Gebiete der Röntgenstrahlen und der Nuklearmedizin 2001;173:702–707 10. Edwards DJ, Lomas D, Villar RN. Diagnosis of the painful hip by MRI and arthroscopy. Journal of Bone and Joint Surgery 1995;77:374–376

11. Eriksson E, Arvidsson I, Arvidsson H. Diagnostic and operative arthroscopy of the hip. Orthopaedics 1986;10:392–399 12. Espinosa N, Rothenfluh DA, Beck M, Ganz R, Leunig M. Treatment of femoro- acetabular impingement: preliminary results of labral refixation. Journal of Bone and Joint Surgery. American Volume 2006;88:2537 13. Fitzgerald RH Jr. Acetabular labral tears: diagnosis and treatment. Clinical Orthopaedics 1995;311:60–68 14. McCarthy JC, Noble PC, Schuck MR, Wright J, Lee J. The Otto E. Aufranc Award: the role of labral lesions to the development of early degenerative hip disease. Clinical Orthopaedics and Related Research 2001;393:25–37 15. Conn KS, Villar RN. Labrum lesions from the viewpoint of arthroscopic hip surgery. Orthopaedics 1998;27:699–703 16. Lephart SM, Ferris CM, Riemann BL, Myers JB, Fu FH. Gender differences in strength and lower extremity kinematics during landing. Clinical Orthopaedics and Related Research 2002;401:162–169 17. Stubbs A. Course notes: sports hip surgery, 2008 18. Bradshaw CJ, Bundy M, Falvey E. The diagnosis of longstanding groin pain: a prospective clinical cohort study. British Journal of Sports Medicine 2008;42:551–554 19. Seldes RM, Tan V, Hunt J, Katz M, et al. Anatomy, histologic features, and vascularity of the adult acetabular labrum. Clinical Orthopaedics and Related Research 2001;382:232–240 20. Hoaglund FT, Steinbach LS. Primary osteoarthritis of the hip: etiology and epidemiology. Journal of the America Academy of Orthopedic Surgery 2001;9:320–327 21. Blankenbaker DG, Tuite MJ. The painful hip: new concepts. Skeletal Radiology 2006;35:352–370 22. Kelly BT, Weiland DE, Schenker ML, Philippon MJ. Arthroscopic labral repair in the hip: surgical technique and review of the

FAI IS A MORPHOLOGICAL CONDITION THAT

literature. Arthroscopy 2005;21:1496– 1504 23. Byrd JW, Jones KS. Arthroscopic femoroplasty in the management of cam-type femoroacetabular impingement. Clinical Orthopaedics and Related Research 2009;467:736–746 24. Tannast M, Goricki D, Beck M, Murphy SB, Siebenrock KA. Hip damage occurs at the zone of femoroacetabular impingement.

Clinical Orthopaedics and Related Research 2008;466:273–280 25. Beck M, Kalhor M, Leunig M, Ganz R. Hip morphology influences the pattern of damage to the acetabular cartilage: femoroacetabular impingement as a cause of early osteoarthritis of the hip. Journal of Bone and Joint Surgery. British Volume 2005;87:1012–1018 26. L’Hermette M, Polle G, Tourny-Chollet C, Dujardin F. Hip passive range of motion and frequency of radiographic hip osteoarthritis in former elite handball players. British Journal of Sports Medicine 2006;40:45– 49 27. Hunt D, Clohisy J, Prather H. Acetabular labral tears of the hip in women. Physical Medicine and Rehabilitation Clinics of North America 2007;18:497–520 28. Pfirrmann CW, Mengiardi B, Dora C, Kalberer F, et al. Cam and pincer femoroacetabular impingement: characteristic MR arthrographic findings in 50 patients. Radiology 2006;240:778– 785 29. James SL, Connell DA, O’Donnell P, Saifuddin A. Femoroacetabular impingement: bone marrow oedema associated with fibrocystic change of the femoral head and neck junction. Clinical Radiology 2007;62:472–478 30. Philippon M. Course notes: sports hip surgery, 2006 31. Neumann M, Cui Q, Siebenrock KA, Beck M. Impingement-free hip motion: the ‘normal’ angle alpha after osteochondroplasty. Clinical Orthopaedics and Related Research 2009;469:699–703 32. Nötzli HP, Wyss TF, Stoecklin CH, Schmid MR, et al. The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. Journal of Bone and Joint Surgery. British Volume 2002;84:556–560

33. Philippon M. ESSKA presentation, 2006 34. Byrd JW, Jones KS. Diagnostic accuracy of clinical assessment, magnetic resonance imaging, magnetic resonance arthrography, and intra-articular injection in hip arthroscopy patients. American Journal of Sports Medicine 2004;32:1668–1674 35. Van den Berg JC. Inguinal hernias: MRI and ultrasound. Seminars in Ultrasound, CT, and MR 2002;23:156–173 36. Leunig M, Podeszwa D, Beck M, Werlen S, Ganz R. Magnetic resonance arthrography of labral disorders in hips with dysplasia and impingement. Clinical Orthopaedics and Related Research 2004;418:74–80 37. Saw T, Villar R. Footballer’s hip a report of six cases. Journal of Bone and Joint Surgery. British Volume 2004;86:655– 658 38. Ganz R, Parvizi J, Beck M, Leunig M,

sportEX medicine 2009;40(Apr):10-15