Comparative Evaluation of Cross-table and Ducroquet Incidences for Measurement of the Hip Alpha Angle^[∗]

Abstract

Objective The purpose of the present paper is to compare the equivalence of the measurement of the alpha angle using the Ducroquet and cross-table lateral views.

Methods We have recruited 90 patients, resulting in 95 hips. We have standardized the realization of the radiographic views. The incidence of the lateral cross-table views were taken with 15° of internal rotation with the patient in the supine position, and the incidence of the Ducroquet views was standardized with the patient in the supine position, with 90° of flexion and 45° of abduction of the hip. The alpha angle was measured in both lateral views, by two musculoskeletal radiologists. The measurements were performed in 2 different times: an initial evaluation and another 4 weeks afterwards. The t Student test was used and calculated the intraclass correlation coefficient (ICC).

Results We have found a good intraobserver correlation for both views in different times; there was no statistically significant difference between the measurements performed by the two views. However, the interobserver correlation was low.

Conclusion In conclusion, the Ducroquet profile view is a good choice for the α angle measurement and can be used instead of the cross-table view.

Keywords

femoracetabular impingement - hip/abnormalities - hip/diagnostic imaging - radiography

^∗ Work performed at the Hip Group, Orthopedics and Traumatology Department, Irmandade Santa Casa de Misericórdia, Faculdade de Ciências Médicas da Santa Casa de São Paulo (FCMSCSP), São Paulo, SP, Brazil.

• Referências

• 1 Clohisy JC, Carlisle JC, Trousdale R, Kim YJ, Beaule PE, Morgan P. , et al. Radiographic evaluation of the hip has limited reliability. Clin Orthop Relat Res 2009; 467 (03) 666-675
• 2 Fadul DA, Carrino JA. Imaging of femoroacetabular impingement. J Bone Joint Surg Am 2009; 91 (Suppl. 01) 138-143
• 3 Dudda M, Albers C, Mamisch TC, Werlen S, Beck M. Do normal radiographs exclude asphericity of the femoral head-neck junction?. Clin Orthop Relat Res 2009; 467 (03) 651-659
• 4 Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular impingement: radiographic diagnosis--what the radiologist should know. AJR Am J Roentgenol 2007; 188 (06) 1540-1552
• 5 Eijer H, Leunig M, Mahomed MN, Ganz R. Cross- table lateral radiographs for screening of anterior femoral head- neck offset in patients with femoro- acetabular impingement. Hip Int 2001; 11 (01) 37-41
• 6 Neumann M, Cui Q, Siebenrock KA, Beck M. Impingement-free hip motion: the ‘normal’ angle alpha after osteochondroplasty. Clin Orthop Relat Res 2009; 467 (03) 699-703
• 7 Fraitzl CR, Käfer W, Nelitz M, Reichel H. Radiological evidence of femoroacetabular impingement in mild slipped capital femoral epiphysis: a mean follow-up of 14.4 years after pinning in situ. J Bone Joint Surg Br 2007; 89 (12) 1592-1596
• 8 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
• 9 Clohisy JC, Nunley RM, Otto RJ, Schoenecker PL. The frog-leg lateral radiograph accurately visualized hip cam impingement abnormalities. Clin Orthop Relat Res 2007; 462 (462) 115-121
• 10 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
• 11 Godefroy D, Chevrot A, Morvan G, Rousselin B, Sarazin L. [Plain films of pelvis]. J Radiol 2008; 89 (5 Pt 2): 679-690 , quiz 691
• 12 Chrétien J. -Lateral views of the hip-. Ann Radiol (Paris) 1997; 40 (01) 5-10
• 13 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
• 14 Loder RT. Effect of femur position on the angular measurement of slipped capital femoral epiphysis. J Pediatr Orthop 2001; 21 (04) 488-494
• 15 Gosvig KK, Jacobsen S, Palm H, Sonne-Holm S, Magnusson E. A new radiological index for assessing asphericity of the femoral head in cam impingement. J Bone Joint Surg Br 2007; 89 (10) 1309-1316
• 16 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