Assessment of Acetabular Morphology Using the Acetabular Anterior Center-Edge Angle on Modified False-Profile Radiographs


      To compare radiographic parameters of acetabular morphology between standard and modified false-profile (FP) radiographs.


      Standard and modified FP radiographs were obtained in 225 hips in 200 consecutive patients evaluated for hip pain and suspected femoroacetabular impingement. Radiographs were retrospectively reviewed by 2 readers to determine the anterior center-edge angle (ACEA), as assessed to the sourcil and to the bone edge. Inter-rater reliability of radiographic measurements was assessed using the intraclass correlation coefficient. Measurements were evaluated for normality with the Shapiro-Wilk test, averaged between the 2 readers, and compared between views using the paired Wilcoxon test.


      The intraclass correlation coefficient values for standard and modified FP views were 0.923 and 0.932, respectively, measuring to the sourcil and 0.867 and 0.896, respectively, measuring to the lateral bone edge. The median difference in ACEA measurements to the sourcil was 1° between the standard and modified FP view (45° vs 44°, P < .001). The median difference in ACEA measurements to the bone edge was 2° (34° vs 32°, P < .001).


      Thirty-five degrees of femoral internal rotation for a modified FP hip radiographic view provides similar clinical information regarding acetabular morphology to that of the standard FP view. Given that the modified FP view also provides better visualization of the anterosuperior head-neck junction cam lesion, the modified FP view may be preferred over the standard FP view in evaluation of hip pain in the young patient.

      Level of Evidence

      Level III, retrospective comparative study.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Arthroscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Clohisy J.C.
        • Carlisle J.C.
        • Beaule P.E.
        • et al.
        A systematic approach to the plain radiographic evaluation of the young adult hip.
        J Bone Joint Surg Am. 2008; 90: 47-66
        • Ganz R.
        • Parvizi J.
        • Beck M.
        • Leunig M.
        • Notzli H.
        • Siebenrock K.A.
        Femoroacetabular impingement: A cause for osteoarthritis of the hip.
        Clin Orthop Relat Res. 2003; 417: 112-120
        • Lequesne M.
        • de Sèze S.
        False profile of the pelvis. A new radiographic incidence for the study of the hip. Its use in dysplasias and different coxopathies.
        Rev Rhum Mal Osteoartic. 1961; 28 ([in French]): 643-652
        • Hellman M.D.
        • Mascarenhas R.
        • Gupta A.
        • et al.
        The false-profile view may be used to identify cam morphology.
        Arthroscopy. 2015; 31: 1728-1732
        • Atkins P.R.
        • Kobayashi E.F.
        • Anderson A.E.
        • Aoki S.K.
        Modified false-profile radiograph of the hip provides better visualization of the anterosuperior femoral head-neck junction.
        Arthroscopy. 2018; 34: 1236-1243
        • Domayer S.E.
        • Ziebarth K.
        • Chan J.
        • Bixby S.
        • Mamisch T.C.
        • Kim Y.J.
        Femoroacetabular cam-type impingement: Diagnostic sensitivity and specificity of radiographic views compared to radial MRI.
        Eur J Radiol. 2011; 80: 805-810
        • Rakhra K.S.
        • Sheikh A.M.
        • Allen D.
        • Beaule P.E.
        Comparison of MRI alpha angle measurement planes in femoroacetabular impingement.
        Clin Orthop Relat Res. 2009; 467: 660-665
        • Siebenrock K.A.
        • Wahab K.H.
        • 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
        • Hanson J.A.
        • Kapron A.L.
        • Swenson K.M.
        • Maak T.G.
        • Peters C.L.
        • Aoki S.K.
        Discrepancies in measuring acetabular coverage: Revisiting the anterior and lateral center edge angles.
        J Hip Preserv Surg. 2015; 2: 280-286
        • Mittal A.
        • Bomar J.D.
        • Jeffords M.E.
        • Huang M.T.
        • Wenger D.R.
        • Upasani V.V.
        Defining the lateral edge of the femoroacetabular articulation: Correlation analysis between radiographs and computed tomography.
        J Child Orthop. 2016; 10: 365-370
        • Anderson L.A.
        • Gililland J.
        • Pelt C.
        • Linford S.
        • Stoddard G.J.
        • Peters C.L.
        Center edge angle measurement for hip preservation surgery: Technique and caveats.
        Orthopedics. 2011; 34: 86
        • Bouttier R.
        • Morvan J.
        • Mazieres B.
        • et al.
        Reproducibility of radiographic hip measurements in adults.
        Joint Bone Spine. 2013; 80: 52-56
        • Mast N.H.
        • Impellizzeri F.
        • Keller S.
        • Leunig M.
        Reliability and agreement of measures used in radiographic evaluation of the adult hip.
        Clin Orthop Relat Res. 2011; 469: 188-199
        • Dolan M.M.
        • Heyworth B.E.
        • Bedi A.
        • Duke G.
        • Kelly B.T.
        CT reveals a high incidence of osseous abnormalities in hips with labral tears.
        Clin Orthop Relat Res. 2011; 469: 831-838
        • Hansen B.J.
        • Harris M.D.
        • Anderson L.A.
        • Peters C.L.
        • Weiss J.A.
        • Anderson A.E.
        Correlation between radiographic measures of acetabular morphology with 3D femoral head coverage in patients with acetabular retroversion.
        Acta Orthop. 2012; 83: 233-239
        • Sakai T.
        • Nishii T.
        • Sugamoto K.
        • Yoshikawa H.
        • Sugano N.
        Is vertical-center-anterior angle equivalent to anterior coverage of the hip?.
        Clin Orthop Relat Res. 2009; 467: 2865-2871
        • Ogata S.
        • Moriya H.
        • Tsuchiya K.
        • Akita T.
        • Kamegaya M.
        • Someya M.
        Acetabular cover in congenital dislocation of the hip.
        J Bone Joint Surg Br. 1990; 72: 190-196
        • Wiberg G.
        Studies on dysplastic acetabulum and congenital subluxation of the hip joint with special reference to the complications of osteoarthritis.
        Acta Chir Scand. 1939; 83
        • Jessel R.H.
        • Zurakowski D.
        • Zilkens C.
        • Burstein D.
        • Gray M.L.
        • Kim Y.J.
        Radiographic and patient factors associated with pre-radiographic osteoarthritis in hip dysplasia.
        J Bone Joint Surg Am. 2009; 91: 1120-1129
        • Sankar W.N.
        • Brighton B.K.
        • Kim Y.J.
        • Millis M.B.
        Acetabular morphology in slipped capital femoral epiphysis.
        J Pediatr Orthop. 2011; 31: 254-258
        • Al-Ghamdi A.
        • Rendon J.S.
        • Al-Faya F.
        • Saran N.
        • Benaroch T.
        • Hamdy R.C.
        Dega osteotomy for the correction of acetabular dysplasia of the hip: A radiographic review of 21 cases.
        J Pediatr Orthop. 2012; 32: 113-120
        • Hosalkar H.
        • Munhoz da Cunha A.L.
        • Baldwin K.
        • Ziebarth K.
        • Wenger D.R.
        Triple innominate osteotomy for Legg-Calve-Perthes disease in children: Does the lateral coverage change with time?.
        Clin Orthop Relat Res. 2012; 470: 2402-2410
        • Philippon M.J.
        • Wolff A.B.
        • Briggs K.K.
        • Zehms C.T.
        • Kuppersmith D.A.
        Acetabular rim reduction for the treatment of femoroacetabular impingement correlates with preoperative and postoperative center-edge angle.
        Arthroscopy. 2010; 26: 757-761
        • Werner C.M.
        • Copeland C.E.
        • Ruckstuhl T.
        • Stromberg J.
        • Turen C.H.
        • Bouaicha S.
        Relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index, and medial acetabular bone stock.
        Skeletal Radiol. 2011; 40: 1435-1439
        • Kappe T.
        • Kocak T.
        • Bieger R.
        • Reichel H.
        • Fraitzl C.R.
        Radiographic risk factors for labral lesions in femoroacetabular impingement.
        Clin Orthop Relat Res. 2011; 469: 3241-3247
        • Nepple J.J.
        • Brophy R.H.
        • Matava M.J.
        • Wright R.W.
        • Clohisy J.C.
        Radiographic findings of femoroacetabular impingement in National Football League Combine athletes undergoing radiographs for previous hip or groin pain.
        Arthroscopy. 2012; 28: 1396-1403
        • Polkowski G.G.
        • Novais E.N.
        • Kim Y.J.
        • Millis M.B.
        • Schoenecker P.L.
        • Clohisy J.C.
        Does previous reconstructive surgery influence functional improvement and deformity correction after periacetabular osteotomy?.
        Clin Orthop Relat Res. 2012; 470: 516-524
        • Ross J.R.
        • Zaltz I.
        • Nepple J.J.
        • Schoenecker P.L.
        • Clohisy J.C.
        Arthroscopic disease classification and interventions as an adjunct in the treatment of acetabular dysplasia.
        Am J Sports Med. 2011; 39: 72S-78S
        • Chosa E.
        • Tajima N.
        Anterior acetabular head index of the hip on false-profile views. New index of anterior acetabular cover.
        J Bone Joint Surg Br. 2003; 85: 826-829
        • Zingg P.O.
        • Werner C.M.
        • Sukthankar A.
        • Zanetti M.
        • Seifert B.
        • Dora C.
        The anterior center edge angle in Lequesne's false profile view: Interrater correlation, dependence on pelvic tilt and correlation to anterior acetabular coverage in the sagital plane. A cadaver study.
        Arch Orthop Trauma Surg. 2009; 129: 787-791
        • Crockarell Jr., J.R.
        • Trousdale R.T.
        • Guyton J.L.
        The anterior centre-edge angle. A cadaver study.
        J Bone Joint Surg Br. 2000; 82: 532-534
        • Nepple J.J.
        • Martel J.M.
        • Kim Y.J.
        • Zaltz I.
        • Clohisy J.C.
        • Group A.S.
        Do plain radiographs correlate with CT for imaging of cam-type femoroacetabular impingement?.
        Clin Orthop Relat Res. 2012; 470: 3313-3320
        • Dudda M.
        • Albers C.
        • Mamisch T.C.
        • Werlen S.
        • Beck M.
        Do normal radiographs exclude asphericity of the femoral head-neck junction?.
        Clin Orthop Relat Res. 2009; 467: 651-659
        • Saito M.
        • Tsukada S.
        • Yoshida K.
        • Okada Y.
        • Tasaki A.
        Correlation of alpha angle between various radiographic projections and radial magnetic resonance imaging for cam deformity in femoral head-neck junction.
        Knee Surg Sports Traumatol Arthrosc. 2017; 25: 77-83

      Linked Article

      • Editorial Commentary: Modified False-Profile View—Two Birds With One Stone?
        ArthroscopyVol. 35Issue 11
        • Preview
          Pathology in the hip is most commonly described using radiographic parameters. Accurately delineating this pathology is paramount in proper diagnosis and care. The anterior center-edge angle measures the anterior coverage of the acetabulum, which has implications in treating the hip. The modified false-profile view will allow visualization of not only the anterior coverage of the femoral head but also the patient's alpha angle. As such, the modified false-profile view could replace both the standard false-profile view and the 45° Dunn view, essentially reducing by 1 the number of images required to evaluate patients presenting with hip symptoms.
        • Full-Text
        • PDF