Femoroacetabular Impingement: What the Surgeon Wants to Know

Paulo Rego; Paul E. Beaulé; Olufemi R. Ayeni; Marc Tey; Oliver Marin-Peña; Pedro Dantas; Geoffrey Wilkin; George Grammatopoulos; Inês Mafra; Kevin Smit; Adrian Z. Kurz

doi:10.1055/s-0039-1683967

Seminars in Musculoskeletal Radiology, Table of Contents

Semin Musculoskelet Radiol 2019; 23(03): 257-275
DOI: 10.1055/s-0039-1683967

Review Article

Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Femoroacetabular Impingement: What the Surgeon Wants to Know

Authors

Paulo Rego

¹Orthopedic Surgery Department, Hospital da Luz, Lisbon, Portugal
Paul E. Beaulé

²Division of Orthopaedic Surgery, University of Ottawa, The Ottawa Hospital, Ottawa, Ontario, Canada
Olufemi R. Ayeni

³Division of Orthopaedic Surgery, McMaster University Medical Centre, Hamilton, Ontario, Canada
Marc Tey

⁴Orthopaedic Surgery Department, Hospital Universitari del Mar, Barcelona, Spain
Oliver Marin-Peña

⁵Orthopedic Surgery Department, Hospital Universitario Infanta Leonor, Madrid, Spain
Pedro Dantas

⁶Orthopedic Surgery Department, Hospital Cuf Descobertas, Lisbon, Portugal
Geoffrey Wilkin

²Division of Orthopaedic Surgery, University of Ottawa, The Ottawa Hospital, Ottawa, Ontario, Canada
George Grammatopoulos

²Division of Orthopaedic Surgery, University of Ottawa, The Ottawa Hospital, Ottawa, Ontario, Canada
Inês Mafra

⁷Hospital Beatriz Ângelo, Av Carlos Teixeira, Loures, Portugal
Kevin Smit

⁸Division of Orthopaedic Surgery, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
Adrian Z. Kurz

³Division of Orthopaedic Surgery, McMaster University Medical Centre, Hamilton, Ontario, Canada

Abstract

Femoroacetabular impingement (FAI) is increasingly recognized as a risk factor for early hip degeneration in young active patients. The diagnosis depends on clinical examination and proper imaging that should be able to identify abnormal and sometimes subtle morphological changes. Labral tears and cartilage lesions rarely occur without underlying bone abnormalities. Surgical approaches to treat FAI are increasing significantly worldwide, even without a clearly defined consensus of what should be accepted as the standard imaging diagnosis for FAI morphology.

Hip abnormalities encompass many variations related to the shape, size, and spatial orientation of both sides of the joint and can be difficult to characterize if adequate imaging is not available.

This article presents a comprehensive review about the information orthopaedic surgeons need to know from radiologists to plan the most rational approach to a painful hip resulting from a mechanical abnormality.

Keywords

femoroacetabular impingement - hip arthroscopy - hip dysplasia - acetabular retroversion - periacetabular osteotomy

Full Text

References

References
1 Smith-Petersen MN. The classic: Treatment of malum coxae senilis, old slipped upper femoral epiphysis, intrapelvic protrusion of the acetabulum, and coxa plana by means of acetabuloplasty. 1936. Clin Orthop Relat Res 2009; 467 (03) 608-615
2 Ito K, Minka II MA, Leunig M, Werlen S, Ganz R. Femoroacetabular impingement and the cam-effect. A MRI-based quantitative anatomical study of the femoral head-neck offset. J Bone Joint Surg Br 2001; 83 (02) 171-176
3 Ganz R, Parvizi J, Beck M, Leunig M, Nötzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res 2003; (417) 112-120
4 Ganz R, Gill TJ, Gautier E, Ganz K, Krügel N, Berlemann U. Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J Bone Joint Surg Br 2001; 83 (08) 1119-1124
5 Siebenrock KA, Wahab KHA, Werlen S, Kalhor M, Leunig M, Ganz R. Abnormal extension of the femoral head epiphysis as a cause of cam impingement. Clin Orthop Relat Res 2004; (418) 54-60
6 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. J Bone Joint Surg Br 2005; 87 (07) 1012-1018
7 Ganz R, Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip: an integrated mechanical concept. Clin Orthop Relat Res 2008; 466 (02) 264-272
8 Corten K, Ganz R, Chosa E, Leunig M. Bone apposition of the acetabular rim in deep hips: a distinct finding of global pincer impingement. J Bone Joint Surg Am 2011; 93 (Suppl. 02) 10-16
9 Kraeutler MJ, Chadayammuri V, Garabekyan T, Mei-Dan O. Femoral version abnormalities significantly outweigh effect of cam impingement on hip internal rotation. J Bone Joint Surg Am 2018; 100 (03) 205-210
10 Murray RO. The aetiology of primary osteoarthritis of the hip. Br J Radiol 1965; 38 (455) 810-824
11 Buckwalter JA, Anderson DD, Brown TD, Tochigi Y, Martin JA. The roles of mechanical stresses in the pathogenesis of osteoarthritis: implications for treatment of joint injuries. Cartilage 2013; 4 (04) 286-294
12 Ganz R, Horowitz K, Leunig M. Algorithm for femoral and periacetabular osteotomies in complex hip deformities. Clin Orthop Relat Res 2010; 468 (12) 3168-3180
13 Leunig M, Puloski S, Beck M, Siebenrock K-A, Ganz R. Proximal femoral osteotomy: current indications and techniques. Semin Arthroplasty 2005; 16: 53-62
14 Tannast M, Macintyre N, Steppacher SD, Hosalkar HS, Ganz R, Siebenrock KA. A systematic approach to analyze the sequelae of LCPD. Hip Int 2013; 23 (Suppl. 09) S61-S70
15 Bogunovic L, Gottlieb M, Pashos G, Baca G, Clohisy JC. Why do hip arthroscopy procedures fail?. Clin Orthop Relat Res 2013; 471 (08) 2523-2529
16 Ross JR, Larson CM, Adeoye O, Kelly BT, Bedi A. Residual deformity is the most common reason for revision hip arthroscopy: a three-dimensional CT study. Clin Orthop Relat Res 2015; 473 (04) 1388-1395
17 Rego PR, Mascarenhas V, Oliveira FS. , et al. Morphologic and angular planning for cam resection in femoro-acetabular impingement: value of the omega angle. Int Orthop 2016; 40 (10) 2011-2017
18 Rego P, Mascarenhas V, Collado D, Coelho A, Barbosa L, Ganz R. Arterial topographic anatomy near the femoral head-neck perforation with surgical relevance. J Bone Joint Surg Am 2017; 99 (14) 1213-1221
19 Marin-Peña O, Tey-Pons M, Perez-Carro L. , et al. The current situation in hip arthroscopy. EFORT Open Rev 2017; 2 (03) 58-65
20 Montgomery SR, Ngo SS, Hobson T. , et al. Trends and demographics in hip arthroscopy in the United States. Arthroscopy 2013; 29 (04) 661-665
21 Peters S, Laing A, Emerson C. , et al. Surgical criteria for femoroacetabular impingement syndrome: a scoping review. Br J Sports Med 2017; 51 (22) 1605-1610
22 Nwachukwu BU, Rebolledo BJ, McCormick F, Rosas S, Harris JD, Kelly BT. Arthroscopic versus open treatment of femoroacetabular impingement: a systematic review of medium- to long-term outcomes. Am J Sports Med 2016; 44 (04) 1062-1068
23 Rego PA, Mascarenhas V, Oliveira FS, Pinto PC, Sampaio E, Monteiro J. Arthroscopic versus open treatment of cam-type femoro-acetabular impingement: retrospective cohort clinical study. Int Orthop 2018; 42 (04) 791-797
24 Nepple JJ, Clohisy JC. ; ANCHOR Study Group Members. Evolution of femoroacetabular impingement treatment: the ANCHOR experience. Am J Orthop 2017; 46 (01) 28-34
25 Zaltz I, Kelly BT, Larson CM, Leunig M, Bedi A. Surgical treatment of femoroacetabular impingement: what are the limits of hip arthroscopy?. Arthroscopy 2014; 30 (01) 99-110
26 Costa Rocha P, Klingenstein G, Ganz R, Kelly BT, Leunig M. Circumferential reconstruction of severe acetabular labral damage using hamstring allograft: surgical technique and case series. Hip Int 2013; 23 (Suppl. 09) S42-S53
27 Audenaert EA, Peeters I, Vigneron L, Baelde N, Pattyn C. Hip morphological characteristics and range of internal rotation in femoroacetabular impingement. Am J Sports Med 2012; 40 (06) 1329-1336
28 Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular impingement: radiographic diagnosis—what the radiologist should know. AJR Am J Roentgenol 2007; 188 (06) 1540-1552
29 Siebenrock KA, Steppacher SD, Haefeli PC, Schwab JM, Tannast M. Valgus hip with high antetorsion causes pain through posterior extraarticular FAI. Clin Orthop Relat Res 2013; 471 (12) 3774-3780
30 Vallon F, Reymond A, Fürnstahl P. , et al. Effect of angular deformities of the proximal femur on impingement-free hip range of motion in a three-dimensional rigid body model. Hip Int 2015; 25 (06) 574-580
31 Larson CM, Clohisy JC, Beaulé PE. , et al; ANCHOR Study Group. Intraoperative and early postoperative complications after hip arthroscopic surgery: a prospective multicenter trial utilizing a validated grading scheme. Am J Sports Med 2016; 44 (09) 2292-2298
32 Robertson WJ, Kelly BT. The safe zone for hip arthroscopy: a cadaveric assessment of central, peripheral, and lateral compartment portal placement. Arthroscopy 2008; 24 (09) 1019-1026
33 Bedi A, Zaltz I, De La Torre K, Kelly BT. Radiographic comparison of surgical hip dislocation and hip arthroscopy for treatment of cam deformity in femoroacetabular impingement. Am J Sports Med 2011; 39 (Suppl): 20S-28S
34 Philippon MJ, Stubbs AJ, Schenker ML, Maxwell RB, Ganz R, Leunig M. Arthroscopic management of femoroacetabular impingement: osteoplasty technique and literature review. Am J Sports Med 2007; 35 (09) 1571-1580
35 Horisberger M, Brunner A, Herzog RF. Arthroscopic treatment of femoroacetabular impingement of the hip: a new technique to access the joint. Clin Orthop Relat Res 2010; 468 (01) 182-190
36 Suslak AG, Mather III RC, Kelly BT, Nho SJ. Improved arthroscopic visualization of peripheral compartment. Arthrosc Tech 2012; 1 (01) e57-e62
37 Nasser R, Domb B. Hip arthroscopy for femoroacetabular impingement. EFORT Open Rev 2018; 3 (04) 121-129
38 Matsuda DK. Acute iatrogenic dislocation following hip impingement arthroscopic surgery. Arthroscopy 2009; 25 (04) 400-404
39 Ranawat AS, McClincy M, Sekiya JK. Anterior dislocation of the hip after arthroscopy in a patient with capsular laxity of the hip. A case report. J Bone Joint Surg Am 2009; 91 (01) 192-197
40 Rosenbaum A, Roberts T, Flaherty M, Phillips N, Patel N, Das P. Posterior dislocation of the hip following arthroscopy—a case report and discussion. Bull Hosp Jt Dis (2013) 2014; 72 (02) 181-184
41 Wylie JD, Beckmann JT, Maak TG, Aoki SK. Arthroscopic capsular repair for symptomatic hip instability after previous hip arthroscopic surgery. Am J Sports Med 2016; 44 (01) 39-45
42 Harris JD, Slikker III W, Gupta AK, McCormick FM, Nho SJ. Routine complete capsular closure during hip arthroscopy. Arthrosc Tech 2013; 2 (02) e89-e94
43 Wuerz TH, Song SH, Grzybowski JS. , et al. Capsulotomy size affects hip joint kinematic stability. Arthroscopy 2016; 32 (08) 1571-1580
44 Kuhns BD, Weber AE, Levy DM. , et al. Capsular management in hip arthroscopy: an anatomic, biomechanical, and technical review. Front Surg 2016; 3: 13
45 Larson CM, Giveans MR. Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement. Arthroscopy 2009; 25 (04) 369-376
46 Greaves LL, Gilbart MK, Yung AC, Kozlowski P, Wilson DR. Effect of acetabular labral tears, repair and resection on hip cartilage strain: A 7T MR study. J Biomech 2010; 43 (05) 858-863
47 Olach M, Gerhard P, Giesinger K, Lampert C, Erhardt JB. Clinical and radiological outcome at mean follow-up of 11 years after hip arthroscopy. Arch Orthop Trauma Surg 2019; 139 (01) 1-6
48 Degen RM, Poultsides L, Mayer SW. , et al. Safety of hip anchor insertion from the midanterior and distal anterolateral portals with a straight drill guide: a cadaveric study. Am J Sports Med 2017; 45 (03) 627-635
49 Liechti EF, Ferguson SJ, Tannast M. Protrusio acetabuli: joint loading with severe pincer impingement and its theoretical implications for surgical therapy. J Orthop Res 2015; 33 (01) 106-113
50 Hanke MS, Steppacher SD, Zurmühle CA, Siebenrock KA, Tannast M. Hips with protrusio acetabuli are at increased risk for failure after femoroacetabular impingement surgery: a 10-year followup. Clin Orthop Relat Res 2016
51 Chandrasekaran S, Darwish N, Martin TJ, Suarez-Ahedo C, Lodhia P, Domb BG. Arthroscopic capsular plication and labral seal restoration in borderline hip dysplasia: 2-year clinical outcomes in 55 cases. Arthroscopy 2017; 33 (07) 1332-1340
52 Wyatt MC, Beck M. The management of the painful borderline dysplastic hip. J Hip Preserv Surg 2018; 5 (02) 105-112
53 Wijdicks CA, Balldin BC, Jansson KS, Stull JD, LaPrade RF, Philippon MJ. Cam lesion femoral osteoplasty: in vitro biomechanical evaluation of iatrogenic femoral cortical notching and risk of neck fracture. Arthroscopy 2013; 29 (10) 1608-1614
54 Ganz R, Gill TJ, Gautier E, Ganz K, Krügel N, Berlemann U. Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J Bone Joint Surg Br 2001; 83 (08) 1119-1124
55 Schoeniger R, LaFrance AE, Oxland TR, Ganz R, Leunig M. Does trochanteric step osteotomy provide greater stability than classic slide osteotomy? A preliminary study. Clin Orthop Relat Res 2009; 467 (03) 775-782
56 Bastian JD, Wolf AT, Wyss TF, Nötzli HP. Stepped osteotomy of the trochanter for stable, anatomic refixation. Clin Orthop Relat Res 2009; 467 (03) 732-738
57 Kalhor M, Beck M, Huff TW, Ganz R. Capsular and pericapsular contributions to acetabular and femoral head perfusion. J Bone Joint Surg Am 2009; 91 (02) 409-418
58 Kalhor M, Horowitz K, Gharehdaghi J, Beck M, Ganz R. Anatomic variations in femoral head circulation. Hip Int 2012; 22 (03) 307-312
59 Kamath AF, Ganz R, Zhang H, Grappiolo G, Leunig M. Subtrochanteric osteotomy for femoral mal-torsion through a surgical dislocation approach. J Hip Preserv Surg 2015; 2 (01) 65-79
60 Weidner J, Wyatt M, Beck M. Labral augmentation with ligamentum capitis femoris: presentation of a new technique and preliminary results. J Hip Preserv Surg 2018; 5 (01) 47-53
61 Steppacher SD, Anwander H, Zurmühle CA, Tannast M, Siebenrock KA. Eighty percent of patients with surgical hip dislocation for femoroacetabular impingement have a good clinical result without osteoarthritis progression at 10 years. Clin Orthop Relat Res 2015; 473 (04) 1333-1341
62 Menge TJ, Briggs KK, Dornan GJ, McNamara SC, Philippon MJ. Survivorship and outcomes 10 years following hip arthroscopy for femoroacetabular impingement: labral debridement compared with labral repair. J Bone Joint Surg Am 2017; 99 (12) 997-1004
63 Palmer DH, Ganesh V, Comfort T, Tatman P. Midterm outcomes in patients with cam femoroacetabular impingement treated arthroscopically. Arthroscopy 2012; 28 (11) 1671-1681
64 Reiman MP, Peters S, Sylvain J, Hagymasi S, Ayeni OR. Prevalence and consistency in surgical outcome reporting for femoroacetabular impingement syndrome: a scoping review. Arthroscopy 2018; 34 (04) 1319-1328.e9
65 Mannion AF, Impellizzeri FM, Naal FD, Leunig M. Fulfilment of patient-rated expectations predicts the outcome of surgery for femoroacetabular impingement. Osteoarthritis Cartilage 2013; 21 (01) 44-50
66 Cicuttini FM, Teichtahl AJ, Wang Y. Hip arthroscopy for femoroacetabular impingement: use escalating beyond the evidence. Med J Aust 2017; 206 (10) 424-426
67 Beaulé PE, Bleeker H, Singh A, Dobransky J. Defining modes of failure after joint-preserving surgery of the hip. Bone Joint J 2017; 99-B (03) 303-309
68 Chegini S, Beck M, Ferguson SJ. The effects of impingement and dysplasia on stress distributions in the hip joint during sitting and walking: a finite element analysis. J Orthop Res 2009; 27 (02) 195-201
69 Hellwig FL, Tong J, Hussell JG. Hip joint degeneration due to cam impingement: a finite element analysis. Comput Methods Biomech Biomed Engin 2016; 19 (01) 41-48
70 Ng KCG, Rouhi G, Lamontagne M, Beaulé PE. Finite element analysis examining the effects of cam FAI on hip joint mechanical loading using subject-specific geometries during standing and maximum squat. HSS J 2012; 8 (03) 206-212
71 Jorge JP, Simões FM, Pires EB. , et al. Finite element simulations of a hip joint with femoroacetabular impingement. Comput Methods Biomech Biomed Engin 2014; 17 (11) 1275-1284
72 Lourenço J, Simões FMF, Rego PA. Finite element analyses of femoroacetabular impingement before and after hip arthroscopy. Biomed Mater Eng 2015; 26 (3-4): 193-206
73 Ferguson SJ. Biomechanics of the Acetabular Labrum [dissertation]. Kingston, Canada: Queen's University; 2001
74 Petersen W, Petersen F, Tillmann B. Structure and vascularization of the acetabular labrum with regard to the pathogenesis and healing of labral lesions. Arch Orthop Trauma Surg 2003; 123 (06) 283-288
75 Fernquest S, Arnold C, Palmer A. , et al. Osseous impingement occurs early in flexion in cam-type femoroacetabular impingement: a 4D CT model. Bone Joint J 2017; 99-B (4, Suppl B): 41-48
76 Meyer DC, Beck M, Ellis T, Ganz R, Leunig M. Comparison of six radiographic projections to assess femoral head/neck asphericity. Clin Orthop Relat Res 2006; 445 (445) 181-185
77 Rippstein J. Determination of the antetorsion of the femur neck by means of two x-ray pictures [in German]. Z Orthop Ihre Grenzgeb 1955; 86 (03) 345-360
78 Locher S, Werlen S, Leunig M, Ganz R. Arthro-MRI mit radiärer Schnittsequenz zur Darstellung der präradiologischen Hüftpathologie. Z Orthop Ihre Grenzgeb 2002; 140 (01) 52-57
79 Nötzli HP, Wyss TF, Stoecklin CH, Schmid MR, Treiber K, Hodler J. The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. J Bone Joint Surg Br 2002; 84 (04) 556-560
80 Martin RK, Dzaja I, Kay J. , et al. Radiographic outcomes following femoroacetabular impingement correction with open surgical management: a systematic review. Curr Rev Musculoskelet Med 2016; 9 (04) 402-410
81 Rakhra KS, Sheikh AM, Allen D, Beaulé PE. Comparison of MRI alpha angle measurement planes in femoroacetabular impingement. Clin Orthop Relat Res 2009; 467 (03) 660-665
82 Bouma HW, Hogervorst T, Audenaert E, Krekel P, van Kampen PM. Can combining femoral and acetabular morphology parameters improve the characterization of femoroacetabular impingement?. Clin Orthop Relat Res 2015; 473 (04) 1396-1403
83 Mascarenhas VV, Rego P, Dantas P, Gaspar A, Soldado F, Consciência JG. Cam deformity and the omega angle, a novel quantitative measurement of femoral head-neck morphology: a 3D CT gender analysis in asymptomatic subjects. Eur Radiol 2017; 27 (05) 2011-2023
84 Cross MB, Fabricant PD, Maak TG, Kelly BT. Impingement (acetabular side). Clin Sports Med 2011; 30 (02) 379-390
85 Philippon MJ, Schenker ML. Arthroscopy for the treatment of femoroacetabular impingement in the athlete. Clin Sports Med 2006; 25 (02) 299-308 , ix
86 Larson CM, Giveans MR, Stone RM. Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement: mean 3.5-year follow-up. Am J Sports Med 2012; 40 (05) 1015-1021
87 Ferguson SJ, Bryant JT, Ganz R, Ito K. An in vitro investigation of the acetabular labral seal in hip joint mechanics. J Biomech 2003; 36 (02) 171-178
88 Siebenrock KA, Kistler L, Schwab JM, Büchler L, Tannast M. The acetabular wall index for assessing anteroposterior femoral head coverage in symptomatic patients. Clin Orthop Relat Res 2012; 470 (12) 3355-3360
89 Kalberer F, Sierra RJ, Madan SS, Ganz R, Leunig M. Ischial spine projection into the pelvis : a new sign for acetabular retroversion. Clin Orthop Relat Res 2008; 466 (03) 677-683
90 Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum. A cause of hip pain. J Bone Joint Surg Br 1999; 81 (02) 281-288
91 Kelly B, Philippon MJ. , eds. Arthroscopic Techniques of the Hip. Thorofare, NJ: Slack Inc; 2009
92 Tannast M, Pfannebecker P, Schwab JM, Albers CE, Siebenrock KA, Büchler L. Pelvic morphology differs in rotation and obliquity between developmental dysplasia of the hip and retroversion. Clin Orthop Relat Res 2012; 470 (12) 3297-3305
93 Zaltz I, Kelly BT, Hetsroni I, Bedi A. The crossover sign overestimates acetabular retroversion. Clin Orthop Relat Res 2013; 471 (08) 2463-2470
94 Leunig M. CORR Insights™: Femoroacetabular impingement predisposes to traumatic posterior hip dislocation. Clin Orthop Relat Res 2013; 471 (06) 1944-1945
95 Steppacher SD, Albers CE, Siebenrock KA, Tannast M, Ganz R. Femoroacetabular impingement predisposes to traumatic posterior hip dislocation. Clin Orthop Relat Res 2013; 471 (06) 1937-1943
96 Zurmühle CA, Anwander H, Albers CE. , et al. Periacetabular osteotomy provides higher survivorship than rim trimming for acetabular retroversion. Clin Orthop Relat Res 2017; 475 (04) 1138-1150
97 Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic tilt on acetabular retroversion: a study of pelves from cadavers. Clin Orthop Relat Res 2003; (407) 241-248
98 Tannast M, Zheng G, Anderegg C. , et al. Tilt and rotation correction of acetabular version on pelvic radiographs. Clin Orthop Relat Res 2005; 438 (438) 182-190
99 Leunig M, Nho SJ, Turchetto L, Ganz R. Protrusio acetabuli: new insights and experience with joint preservation. Clin Orthop Relat Res 2009; 467 (09) 2241-2250
100 Anderson LA, Anderson MB, Erickson JA, Chrastil J, Peters CL. Acetabular wall indices help to distinguish acetabular coverage in asymptomatic adults with varying morphologies. Clin Orthop Relat Res 2017; 475 (04) 1027-1033
101 Anderson LA, Kapron AL, Aoki SK, Peters CL. Coxa profunda: is the deep acetabulum overcovered?. Clin Orthop Relat Res 2012; 470 (12) 3375-3382
102 Nepple JJ, Lehmann CL, Ross JR, Schoenecker PL, Clohisy JC. Coxa profunda is not a useful radiographic parameter for diagnosing pincer-type femoroacetabular impingement. J Bone Joint Surg Am 2013; 95 (05) 417-423
103 Beaulé PE, Byrd T, Wilkin G. , et al. Nonarthroplasty Joint-Preserving Surgery for Hip Disorders. Orthopaedic Knowledge Update: Hip and Knee Reconstruction 5. Philadelphia, PA: Lippincott Williams & Wilkins; 2016
104 McKibbin B. Anatomical factors in the stability of the hip joint in the newborn. J Bone Joint Surg Br 1970; 52 (01) 148-159
105 Menschik F. The hip joint as a conchoid shape. J Biomech 1997; 30 (09) 971-973
106 Bullough P, Goodfellow J, O'Conner J. The relationship between degenerative changes and load-bearing in the human hip. J Bone Joint Surg Br 1973; 55 (04) 746-758
107 Grammatopoulos G, Speirs AD, Ng KCG. , et al. Acetabular and spino-pelvic morphologies are different in subjects with symptomatic cam femoro-acetabular impingement. J Orthop Res 2018; 36 (07) 1840-1848
108 Gilles B, Christophe FK, Magnenat-Thalmann N. , et al. MRI-based assessment of hip joint translations. J Biomech 2009; 42 (09) 1201-1205
109 Beaulé PE, Grammatopoulos G, Speirs A. , et al. Unravelling the hip pistol grip/cam deformity: origins to joint degeneration. J Orthop Res 2018; 36 (12) 3125-3135
110 Speirs AD, Beaulé PE, Rakhra KS, Schweitzer ME, Frei H. Bone density is higher in cam-type femoroacetabular impingement deformities compared to normal subchondral bone. Osteoarthritis Cartilage 2013; 21 (08) 1068-1073
111 Nepple JJ, Prather H, Trousdale RT. , et al. Clinical diagnosis of femoroacetabular impingement. J Am Acad Orthop Surg 2013; 21 (Suppl. 01) S16-S19
112 Larson CM, Kelly BT, Stone RM. Making a case for anterior inferior iliac spine/subspine hip impingement: three representative case reports and proposed concept. Arthroscopy 2011; 27 (12) 1732-1737
113 Ng KCG, Lamontagne M, Jeffers JRT, Grammatopoulos G, Beaulé PE. Anatomic predictors of sagittal hip and pelvic motions in patients with a cam deformity. Am J Sports Med 2018; 46 (06) 1331-1342
114 Mascarenhas VV, Rego P, Dantas P. , et al. Can we discriminate symptomatic hip patients from asymptomatic volunteers based on anatomic predictors? A 3-dimensional magnetic resonance study on cam, pincer, and spinopelvic parameters. Am J Sports Med 2018; 46 (13) 3097-3110
115 Jamali AA, Mladenov K, Meyer DC. , et al. Anteroposterior pelvic radiographs to assess acetabular retroversion: high validity of the “cross-over-sign.”. J Orthop Res 2007; 25 (06) 758-765
116 Dandachli W, Islam SU, Liu M, Richards R, Hall-Craggs M, Witt J. Three-dimensional CT analysis to determine acetabular retroversion and the implications for the management of femoro-acetabular impingement. J Bone Joint Surg Br 2009; 91 (08) 1031-1036
117 Tönnis D, Storch K, Ulbrich H. Results of newborn screening for CDH with and without sonography and correlation of risk factors. J Pediatr Orthop 1990; 10 (02) 145-152
118 Cooperman DR, Wallensten R, Stulberg SD. Acetabular dysplasia in the adult. Clin Orthop Relat Res 1983; (175) 79-85
119 Pitto RP, Klaue K, Ganz R, Ceppatelli S. Acetabular rim pathology secondary to congenital hip dysplasia in the adult. A radiographic study. Chir Organi Mov 1995; 80 (04) 361-368
120 Tönnis D, Heinecke A. Acetabular and femoral anteversion: relationship with osteoarthritis of the hip. J Bone Joint Surg Am 1999; 81 (12) 1747-1770
121 Dandachli W, Kannan V, Richards R, Shah Z, Hall-Craggs M, Witt J. Analysis of cover of the femoral head in normal and dysplastic hips: new CT-based technique. J Bone Joint Surg Br 2008; 90 (11) 1428-1434
122 Jacobsen S, Rømer L, Søballe K. The other hip in unilateral hip dysplasia. Clin Orthop Relat Res 2006; 446 (446) 239-246
123 Wilkin GP, Ibrahim MM, Smit KM, Beaulé PE. A contemporary definition of hip dysplasia and structural instability: toward a comprehensive classification for acetabular dysplasia. J Arthroplasty 2017; 32 (9S): S20-S27
124 Seldes RM, Tan V, Hunt J, Katz M, Winiarsky R, Fitzgerald Jr RH. Anatomy, histologic features, and vascularity of the adult acetabular labrum. Clin Orthop Relat Res 2001; (382) 232-240
125 Safran MR. The acetabular labrum: anatomic and functional characteristics and rationale for surgical intervention. J Am Acad Orthop Surg 2010; 18 (06) 338-345
126 Song Y, Ito H, Kourtis L, Safran MR, Carter DR, Giori NJ. Articular cartilage friction increases in hip joints after the removal of acetabular labrum. J Biomech 2012; 45 (03) 524-530
127 Herickhoff PK, Safran MR. Surgical decision making for acetabular labral tears: an international perspective. Orthop J Sports Med 2018; 6 (09) 2325967118797324
128 Philippon MJ, Michalski MP, Campbell KJ. , et al. An anatomical study of the acetabulum with clinical applications to hip arthroscopy. J Bone Joint Surg Am 2014; 96 (20) 1673-1682
129 Garabekyan T, Ashwell Z, Chadayammuri V. , et al. Lateral acetabular coverage predicts the size of the hip labrum. Am J Sports Med 2016; 44 (06) 1582-1589
130 Petersen BD, Wolf B, Lambert JR. , et al. Lateral acetabular labral length is inversely related to acetabular coverage as measured by lateral center edge angle of Wiberg. J Hip Preserv Surg 2016; 3 (03) 190-196
131 James S, Miocevic M, Malara F, Pike J, Young D, Connell D. MR imaging findings of acetabular dysplasia in adults. Skeletal Radiol 2006; 35 (06) 378-384
132 Philippon MJ, Briggs KK, Yen Y-M, Kuppersmith DA. Outcomes following hip arthroscopy for femoroacetabular impingement with associated chondrolabral dysfunction: minimum two-year follow-up. J Bone Joint Surg Br 2009; 91 (01) 16-23
133 Beck M, Leunig M, Parvizi J, Boutier V, Wyss D, Ganz R. Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment. Clin Orthop Relat Res 2004; (418) 67-73
134 O'Connor M, Minkara AA, Westermann RW, Rosneck J, Lynch TS. Outcomes of joint preservation procedures for cartilage injuries in the hip: a systematic review and meta-analysis. Orthop J Sports Med 2018; 6 (06) 2325967118776944
135 MacDonald AE, Bedi A, Horner NS. , et al. Indications and outcomes for microfracture as an adjunct to hip arthroscopy for treatment of chondral defects in patients with femoroacetabular impingement: a systematic review. Arthroscopy 2016; 32 (01) 190-200.e2
136 Nakano N, Gohal C, Duong A, Ayeni OR, Khanduja V. Outcomes of cartilage repair techniques for chondral injury in the hip—a systematic review. Int Orthop 2018; 42 (10) 2309-2322
137 Palmer A, Fernquest S, Rombach I. , et al. Diagnostic and prognostic value of delayed Gadolinium Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) in early osteoarthritis of the hip. Osteoarthritis Cartilage 2017; 25 (09) 1468-1477
138 Bittersohl B, Hosalkar HS, Hesper T, Tiderius CJ, Zilkens C, Krauspe R. Advanced imaging in femoroacetabular impingement: current state and future prospects. Front Surg 2015; 2: 34
139 Gallagher JR. Fracture of the anterior inferior spine of the ileum: sprinter's fracture. Ann Surg 1935; 102 (01) 86-88
140 Hetsroni I, Larson CM, Dela Torre K, Zbeda RM, Magennis E, Kelly BT. Anterior inferior iliac spine deformity as an extra-articular source for hip impingement: a series of 10 patients treated with arthroscopic decompression. Arthroscopy 2012; 28 (11) 1644-1653
141 Hetsroni I, Poultsides L, Bedi A, Larson CM, Kelly BT. Anterior inferior iliac spine morphology correlates with hip range of motion: a classification system and dynamic model. Clin Orthop Relat Res 2013; 471 (08) 2497-2503
142 Morales-Avalos R, Leyva-Villegas JI, Sanchez-Mejorada G. , et al. A new morphological classification of the anterior inferior iliac spine. relevance in subspine hip impingement. Int J Morphol 2016; 91 (04) 391-397
143 El-Shaar R, Stanton M, Biehl S, Giordano B. Effect of subspine decompression on rectus femoris integrity and iliopsoas excursion: a cadaveric study. Arthroscopy 2015; 31 (10) 1903-1908
144 Chadayammuri V, Garabekyan T, Bedi A. , et al. Passive hip range of motion predicts femoral torsion and acetabular version. J Bone Joint Surg Am 2016; 98 (02) 127-134
145 Lerch TD, Todorski IAS, Steppacher SD. , et al. Prevalence of femoral and acetabular version abnormalities in patients with symptomatic hip disease: a controlled study of 538 hips. Am J Sports Med 2018; 46 (01) 122-134
146 Ricciardi BF, Fields KG, Wentzel C, Kelly BT, Sink EL. Short-term outcomes of open hip preservation surgery for symptomatic extraarticular femoroacetabular impingement. Hip Int 2017; 27 (06) 599-607
147 Johnson KA. Impingement of the lesser trochanter on the ischial ramus after total hip arthroplasty. Report of three cases. J Bone Joint Surg Am 1977; 59 (02) 268-269
148 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 (05) 619-627
149 Ganz R, Slongo T, Turchetto L, Massè A, Whitehead D, Leunig M. The lesser trochanter as a cause of hip impingement: pathophysiology and treatment options. Hip Int 2013; 23 (Suppl. 09) S35-S41
150 Gilligan I, Chandraphak S, Mahakkanukrauh P. Femoral neck-shaft angle in humans: variation relating to climate, clothing, lifestyle, sex, age and side. J Anat 2013; 223 (02) 133-151
151 Toogood PA, Skalak A, Cooperman DR. Proximal femoral anatomy in the normal human population. Clin Orthop Relat Res 2009; 467 (04) 876-885
152 Tönnis D. Normal values of the hip joint for the evaluation of X-rays in children and adults. Clin Orthop Relat Res 1976; (119) 39-47