Normative values of the alpha angle and triangular index measured from the hip radiographs of an African population

Andjelković, 2013, Merenje osteohondralnog spoja glave i vrata femura kod bolesnika sa femoroacetabularnim impingement-om odredivanjem ugla 2α na lateralnim i anteroposteriornim radiografskim snimcima kuka, Vojnosanit Pregl, 70, 259 Ganz, 2003, Femoroacetabular impingement: a cause for osteoarthritis of the hip, Clin Orthop Relat Res, 417, 112, 10.1097/01.blo.0000096804.78689.c2 Griffin, 2016, The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement, Br J Sports Med, 50, 1169, 10.1136/bjsports-2016-096743 Cassar-pullicino, 2016, Femoral head asphericity in cam-type femoroacetabular impingement, Meas Musculoskelet Radiol, 490 Gosvig, 2007, A new radiological index for assessing asphericity of the femoral head in cam impingement, J Bone Jt Surg Ser B, 89, 1309, 10.1302/0301-620X.89B10.19405 Marín-Peña, 2012, 1 Ghaffari, 2018, Current Concepts of Femoroacetabular Impingement, Radiol Clin North Am, 56, 965, 10.1016/j.rcl.2018.06.009 Nötzli, 2002, The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement, J Bone Jt Surg Ser B, 84, 556, 10.1302/0301-620X.84B4.0840556 Beaulé, 2005, Three-dimensional computed tomography of the hip in the assessment of femoroacetabular impingement, J Orthop Res, 23, 1286, 10.1016/j.orthres.2005.03.011.1100230608 Neumann, 2009, Impingement-free hip motion: the “normal” angle alpha after osteochondroplasty, Clin Orthop Relat Res, 467, 699, 10.1007/s11999-008-0616-6 Lim, 2015, Plain radiography of the hip: a review of radiographic techniques and image features, Hip Pelvis, 27, 125, 10.5371/hp.2015.27.3.125 Kumar, 2011, Femoroacetabular impingement and risk factors: a study of 50 cases, Orthop Surg, 3, 236, 10.1111/j.1757-7861.2011.00157.x Fischer, 2018, What are the reference values and associated factors for center-edge angle and alpha angle? A population-based study, Clin Orthop Relat Res, 476, 2249, 10.1097/CORR.0000000000000410 Laborie, 2014, The alpha angle in cam-type femoroacetabular impingement: new reference intervals based on 2038 healthy young adults, Bone Jt J, 96 B, 449, 10.1302/0301-620X.96B4.32194 Haug, 2020, Corrections in alpha angle following two different operative approaches for CAM-type femoral acetabular impingement-Ganz surgical hip dislocation vs anterior mini-open, World J Orthop, 11, 27, 10.5312/wjo.v11.i1.27 Fraitzl, 2013, Femoral head-neck offset measurements in 339 subjects: distribution and implications for femoroacetabular impingement, Knee Surg Sports Traumatol Arthrosc, 21, 1212, 10.1007/s00167-012-2042-2 Agricola, 2014, Cam impingement: Defining the presence of a cam deformity by the alpha angle. Data from the CHECK cohort and Chingford cohort, Osteoarthr Cartil, 22, 218, 10.1016/j.joca.2013.11.007 van Klij, 2020, Classifying cam morphology by the alpha angle: a systematic review on threshold values, Orthop J Sport Med, 8