Andronic Octavian, Rahm Stefan, Fritz Benjamin, Singh Sarvpreet, Sutter Reto, Zingg Patrick O
Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland.
Department of Radiology, Balgrist University Hospital, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland.
Eur J Orthop Surg Traumatol. 2022 Dec;32(8):1481-1489. doi: 10.1007/s00590-021-03123-9. Epub 2021 Sep 22.
External snapping hip syndrome (ESH) is postulated to be one of the causes of greater trochanteric pain syndrome, which also includes greater trochanteric bursitis and tendinopathy or tears of the hip abductor mechanism. However, it was not yet described what kind of bony morphology can cause the snapping and whether symptomatic and asymptomatic individuals have different imaging features.
It was the purpose of this study to look for predisposing morphological factors for ESH and to differentiate between painful and asymptomatic snapping.
A consecutive cohort with ESH and available magnetic resonance imaging (MRI) between 2014 and 2019 was identified. The control group consisted of patients that underwent corrective osteotomies around the knee for mechanical axis correction and never complained of hip symptoms nor had undergone previous hip procedures. The following parameters were blindly assessed for determination of risk factors for ESH: CCD (corpus collum diaphysis) angle; femoral and global offset; femoral antetorsion; functional femoral antetorsion; translation of the greater trochanter (GT); posterior tilt of the GT; pelvic width/anterior pelvic length; intertrochanteric width. Hip and pelvic offset indexes were calculated as ratios of femoral/global offset and intertrochanteric/pelvic width, respectively. For the comparison of symptomatic and asymptomatic snapping, the following soft-tissue signs were investigated: presence of trochanteric bursitis or gluteal tendinopathy; presence of surface bony irregularities on trochanter major and ITB (Iliotibial band) thickness.
A total of 31 hips with ESH were identified. The control group (n = 29) consisted of patients matched on both age (± 1) and gender. Multiple regression analysis determined an increased hip offset index to be independent predictor of ESH (r = + 0.283, p = 0.025), most likely due to the higher femoral offset in the ESH group (p = 0.031). Pearson correlation analysis could not identify any significant secondary factors. No differences were found between painful and asymptomatic snapping on MRI.
A high hip offset index was found as an independent predictor for external snapping hip in our cohort, mainly due to increased femoral offset. No imaging soft-tissue related differences could be outlined between symptomatic and asymptomatic external snapping.
This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00590 .
外侧弹响髋综合征（ESH）被认为是大转子疼痛综合征的病因之一，大转子疼痛综合征还包括大转子滑囊炎以及髋外展机制的肌腱病或撕裂。然而，尚未描述何种骨质形态会导致弹响，以及有症状和无症状个体是否具有不同的影像学特征。
本研究旨在寻找ESH的易感形态学因素，并区分疼痛性和无症状性弹响。
确定了2014年至2019年间患有ESH且有可用磁共振成像（MRI）的连续队列。对照组由因机械轴矫正而接受膝关节周围截骨术且从未抱怨过髋部症状且既往未接受过髋部手术的患者组成。对以下参数进行盲法评估以确定ESH的危险因素：CCD（股骨干颈）角；股骨和整体偏移；股骨前倾角；功能性股骨前倾角；大转子（GT）的平移；GT的后倾；骨盆宽度/骨盆前长度；转子间宽度。髋部和骨盆偏移指数分别计算为股骨/整体偏移和转子间/骨盆宽度的比值。为了比较有症状和无症状弹响，研究了以下软组织征象：转子滑囊炎或臀肌腱病的存在；大转子表面骨质不规则的存在以及髂胫束（ITB）厚度。
共确定了31例患有ESH的髋部。对照组（n = 29）由年龄（±1）和性别匹配的患者组成。多元回归分析确定髋部偏移指数增加是ESH的独立预测因素（r = +0.283，p = 0.025），最可能的原因是ESH组中股骨偏移较高（p = 0.031）。Pearson相关性分析未发现任何显著的次要因素。MRI上疼痛性和无症状性弹响之间未发现差异。
在我们的队列中发现高髋部偏移指数是外侧弹响髋的独立预测因素，主要是由于股骨偏移增加。有症状和无症状外侧弹响之间未发现与影像学软组织相关的差异。
证据水平III：本杂志要求作者为每篇文章指定证据水平。有关这些循证医学评级的完整描述，请参阅目录或在线作者指南 www.springer.com/00590 。
