PURPOSE: This study was designed to evaluate whether the mechanical axis deviation (MAD) of the leg correlates with an increased hip alpha angle as described by Nötzli, which is associated with femoroacetabular impingement (FAI). METHODS: In a retrospective analysis, standing full-length anteroposterior radiographs were analysed in patients who suffered from symptomatic leg alignment. The study included 85 radiographs of 80 patients with an average age of 43.11 years (range 18-60 years). Five patients underwent a bilateral long-leg X-ray examination. All radiographs were transferred as Digital Imaging and Communications in Medicine data files from the Picture Archiving and Communications System into the OrthoPlanner software version 2.3.2. The radiographs were measured by one orthopaedic surgeon and one independent radiologist. RESULTS: The mean value of the alpha angle of Nötzli was 61.43° (49.07-74.04°). A total of 57 (67%) radiographs showed a varus deviation, 25 (29.5%) had a valgus malalignment and three (3.5%) a straight leg axis. Of 82 radiographs, 40 (48.8%) had a moderate axis deviation with a MAD <15 or > - 15 mm and a mean alpha angle of 57.81°, and 42 (51.2%) with extended axis deviation of a MAD > 15 or < - 15 mm had a mean alpha angle of 62.93°; 40 (95.2%) of these 42 showed an alpha angle > 55°. The alpha angle was significantly increased in extended axis deviation compared to moderate axis deviation (P = 0.001). CONCLUSIONS: This study confirmed that increased alpha angles were found significantly at higher degrees of axis deviation on the full-length radiograph. In cases of a MAD >15 or < - 15 mm and symptomatic coxalgia, diagnostic tests must be pursued for FAI.
PURPOSE: This study was designed to evaluate whether the mechanical axis deviation (MAD) of the leg correlates with an increased hip alpha angle as described by Nötzli, which is associated with femoroacetabular impingement (FAI). METHODS: In a retrospective analysis, standing full-length anteroposterior radiographs were analysed in patients who suffered from symptomatic leg alignment. The study included 85 radiographs of 80 patients with an average age of 43.11 years (range 18-60 years). Five patients underwent a bilateral long-leg X-ray examination. All radiographs were transferred as Digital Imaging and Communications in Medicine data files from the Picture Archiving and Communications System into the OrthoPlanner software version 2.3.2. The radiographs were measured by one orthopaedic surgeon and one independent radiologist. RESULTS: The mean value of the alpha angle of Nötzli was 61.43° (49.07-74.04°). A total of 57 (67%) radiographs showed a varus deviation, 25 (29.5%) had a valgus malalignment and three (3.5%) a straight leg axis. Of 82 radiographs, 40 (48.8%) had a moderate axis deviation with a MAD <15 or > - 15 mm and a mean alpha angle of 57.81°, and 42 (51.2%) with extended axis deviation of a MAD > 15 or < - 15 mm had a mean alpha angle of 62.93°; 40 (95.2%) of these 42 showed an alpha angle > 55°. The alpha angle was significantly increased in extended axis deviation compared to moderate axis deviation (P = 0.001). CONCLUSIONS: This study confirmed that increased alpha angles were found significantly at higher degrees of axis deviation on the full-length radiograph. In cases of a MAD >15 or < - 15 mm and symptomatic coxalgia, diagnostic tests must be pursued for FAI.
Authors: Klaus A Siebenrock; Simon Damian Steppacher; Pascal Cyrill Haefeli; Joseph Michael Schwab; Moritz Tannast Journal: Clin Orthop Relat Res Date: 2013-12 Impact factor: 4.176
Authors: Martin Beck; Michael Leunig; Javad Parvizi; Vincent Boutier; Daniel Wyss; Reinhold Ganz Journal: Clin Orthop Relat Res Date: 2004-01 Impact factor: 4.176
Authors: Reinhold Ganz; Javad Parvizi; Martin Beck; Michael Leunig; Hubert Nötzli; Klaus A Siebenrock Journal: Clin Orthop Relat Res Date: 2003-12 Impact factor: 4.176
Authors: Matthias Lahner; Simone Bader; Philipp Alexander Walter; Christian Duif; Christoph von Schulze Pellengahr; Carsten Lukas; Andreas Ficklscherer; Stefan Fickert; Marco Hagen Journal: Int Orthop Date: 2014-08-14 Impact factor: 3.075
Authors: Matthias Lahner; Christoph von Schulze Pellengahr; Philipp Alexander Walter; Carsten Lukas; Andreas Falarzik; Kiriakos Daniilidis; Lars Victor von Engelhardt; Christoph Abraham; Ewald M Hennig; Marco Hagen Journal: BMC Musculoskelet Disord Date: 2014-03-16 Impact factor: 2.362