Davidovitch Roy I, DelSole Edward M, Vigdorchik Jonathan M
Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York - USA.
Hip Int. 2016 Mar 23;26(2):e24-9. doi: 10.5301/hipint.5000351.
Instability is a common cause of revision hip arthroplasty and is frequently due to improper component placement and subsequent component impingement. Impingement of the greater trochanter upon the anterior inferior iliac spine (AIIS) has been described as a cause of symptomatic femoroacetabular impingement (FAI), but has never been described as a cause of instability following total hip arthroplasty (THA).
We present 2 cases of patients undergoing THA. Each patient was evaluated preoperatively and found to have a prominent AIIS, which was concerning due to it overhanging the anterolateral acetabular lip. Both patients had intraoperative posterior instability of their THA, the cause of which was determined to be impingement of the greater trochanter upon a prominent AIIS. Open resection of the AIIS was performed with subsequent resolution of impingement.
AIIS impingement has been reported as a cause of symptomatic FAI. In these case reports, open or arthroscopic resection of the AIIS resulted in resolution of symptoms. Morphologically distinct subtypes of the AIIS have been previously described based upon computed tomography, and some subtypes are associated with a high risk of impingement in the native hip. No previous studies have described this phenomenon in the setting of THA.
Instability is a common cause of revision THA. Impingement of the greater trochanter upon a prominent AIIS is a previously unreported cause of THA instability which can be addressed with intraoperative resection of the AIIS with good result.
不稳定是髋关节翻修术的常见原因，通常是由于假体放置不当及随后的假体撞击所致。大转子撞击髂前下棘（AIIS）已被描述为有症状的股骨髋臼撞击症（FAI）的一个原因，但从未被描述为全髋关节置换术（THA）后不稳定的原因。
我们报告2例接受THA的患者。每位患者术前评估均发现AIIS突出，因其悬于髋臼前外侧唇上方而令人担忧。两名患者THA术中均出现后方不稳定，其原因被确定为大转子撞击突出的AIIS。对AIIS进行了开放性切除，随后撞击得以缓解。
AIIS撞击已被报道为有症状的FAI的一个原因。在这些病例报告中，AIIS的开放性或关节镜下切除使症状得到缓解。先前已根据计算机断层扫描描述了AIIS形态学上不同的亚型，一些亚型与原生髋关节撞击的高风险相关。以前没有研究在THA背景下描述过这种现象。
不稳定是THA翻修的常见原因。大转子撞击突出的AIIS是THA不稳定的一个先前未报道的原因，可通过术中切除AIIS来解决，效果良好。
