Background:

Symptomatic patients with femoroacetabular impingement (FAI) have limitations in daily activities and sports and report the exacerbation of hip pain in deep flexion. Yet, the exact impingement location in deep flexion and the effect of femoral version (FV) are unclear.

Purpose:

To investigate the acetabular and femoral locations of intra- or extra-articular hip impingement in flexion in patients with FAI with and without femoral retroversion.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

An institutional review board–approved retrospective study involving 84 hips (68 participants) was performed. Of these, symptomatic patients (37 hips) with anterior FAI and femoral retroversion (FV <5°) were compared with symptomatic patients (21 hips) with anterior FAI (normal FV) and with a control group (26 asymptomatic hips without FAI and normal FV). All patients were symptomatic, had anterior hip pain, and had positive anterior impingement test findings. Most of the patients had hip/groin pain in maximal flexion or deep flexion or during sports. All 84 hips underwent pelvic computed tomography (CT) to measure FV as well as validated dynamic impingement simulation with patient-specific CT-based 3-dimensional models using the equidistant method.

Results:

In maximal hip flexion, femoral impingement was located anterior-inferior at 4 o’clock (57%) and 5 o’clock (32%) in patients with femoral retroversion and mostly at 5 o’clock in patients without femoral retroversion (69%) and in asymptomatic controls (76%). Acetabular intra-articular impingement was located anterior-superior (2 o’clock) in all 3 groups. In 125° of flexion, patients with femoral retroversion had a significantly (P < .001) higher prevalence of anterior extra-articular subspine impingement (54%) and anterior intra-articular impingement (89%) compared with the control group (29% and 62%, respectively).

Conclusion:

Knowing the exact location of hip impingement in deep flexion has implications for surgical treatment, sports, and physical therapy and confirms previous recommendations: Deep flexion (eg, during squats/lunges) should be avoided in patients with FAI and even more in patients with femoral retroversion. Patients with femoral retroversion may benefit and have less pain when avoiding deep flexion. For these patients, the femoral location of the impingement conflict in flexion was different (anterior-inferior) and distal to the cam deformity compared with the location during the anterior impingement test (anterior-superior). This could be important for preoperative planning and bone resection (cam resection or acetabular rim trimming) during hip arthroscopy or open hip preservation surgery to ensure that the region of impingement is appropriately identified before treatment.

中文翻译：

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有和没有股骨后倾的股骨髋臼撞击患者髋关节撞击位置在最大髋关节屈曲中的位置

背景：

有症状的股骨髋臼撞击 (FAI) 患者在日常活动和运动中受到限制，并报告在深屈时髋部疼痛加剧。然而，深屈曲的确切撞击位置和股骨旋转（FV）的影响尚不清楚。

目的：

调查有和没有股骨后倾的 FAI 患者屈曲时髋臼和股骨关节内或关节外撞击的位置。

学习规划：

横断面研究；证据水平，3。

方法：

进行了一项机构审查委员会批准的回顾性研究，涉及 84 髋（68 名参与者）。其中，有症状的前 FAI 和股骨后倾（FV <5°）的患者（37 髋）与有症状的前 FAI（正常 FV）患者（21 髋）和对照组（26 无 FAI 和正常的无症状髋）进行了比较。 FV)。所有患者都有症状，有髋关节前部疼痛，并且前部撞击试验结果呈阳性。大多数患者在最大屈曲或深屈曲或运动过程中出现髋/腹股沟疼痛。所有 84 髋均接受了盆腔计算机断层扫描 (CT) 以测量 FV，并使用等距方法使用基于患者特定 CT 的 3 维模型验证了动态撞击模拟。

结果：

在最大髋关节屈曲时，股骨后倾患者的股骨撞击位于前下方的 4 点钟（57%）和 5 点钟（32%），而没有股骨后倾的患者大多位于 5 点钟（69%） ) 和无症状对照组 (76%)。3组髋臼关节内撞击均位于前上（2点钟）。在 125° 屈曲时，股骨后倾患者与对照组 (29%) 相比，前关节外脊柱下撞击 (54%) 和前关节内撞击 (89%) 的发生率显着 ( P < .001)和 62%，分别）。

结论：

了解深屈曲时髋部撞击的确切位置对手术治疗、运动和物理治疗具有重要意义，并证实了之前的建议：FAI 患者应避免深屈（例如，在深蹲/弓步期间），股骨骨折患者更应避免倒转。股骨后倾的患者在避免深屈时可能会受益并且疼痛更少。对于这些患者，与前部撞击试验中的位置（前-上）相比，屈曲时撞击冲突的股骨位置是不同的（前-下）和远离凸轮畸形的位置。