Background:

Femoroacetabular impingement (FAI) is one of the most common causes of hip osteoarthritis, yet the factors controlling disease progression are poorly understood.

Purpose:

To investigate rates of initial and subsequent symptoms in the contralateral hip of patients with FAI, and identify predictors of disease progression (symptom development and surgical intervention) in the contralateral hip.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

This prospective study included a minimum 5-year follow-up of the contralateral hip in 179 patients undergoing FAI surgery. Symptoms (moderate pain) and surgical progression were monitored. Univariate and multivariate analyses compared patient-specific and imaging characteristics of symptomatic patients with those who remained asymptomatic to identify factors associated with disease progression.

Results:

A total of 150 patients (84% follow-up) were followed for a mean of 7.1 years (range, 5-11 years). Thirty-nine of these patients (26% [39/150]) had contralateral hip symptoms at initial evaluation. Of those without contralateral hip symptoms at initial evaluation, 32% (36/111) had developed contralateral hip symptoms by latest follow-up. Those who developed symptoms during the study period had a lower anteroposterior head-neck offset ratio (0.153 vs 0.165; P = .005), decreased total arc of rotation in 90° of flexion (39.9° vs 51.1°; P = .005), and decreased external rotation in 90° of flexion (28.6° vs 37.1°; P = .003) compared with those who never developed symptoms. Age, sex, body mass index, alpha angle, lateral center-edge angle, internal rotation in flexion, and University of California, Los Angeles (UCLA), activity score were similar between these groups. Those with contralateral symptoms at initial evaluation progressed to contralateral surgery at a rate of 41% (16/39) and those who developed contralateral symptoms during the study period progressed to contralateral surgery at a rate of 28% (10/36). Among those with contalateral hip symptoms (either present initially or developed during study period)), younger age (24.6 vs 34.1 years; P < .001) and baseline UCLA activity score ≥9 (P = .003) were associated with progression to surgery. By Kaplan-Meier analysis, 64%, 54%, and 48% of patients remained free of contralateral hip symptoms at 2, 5, and 10 years.

Conclusion:

At a mean follow-up of 7.1 years, significant symptoms in the contralateral hip of patients with FAI were present in approximately 50% of patients. FAI disease progression (symptom development and surgical intervention) was associated with decreased hip rotation arc, decreased external rotation, and decreased head-neck offset ratio. In symptomatic patients, younger age and UCLA activity score ≥9 were associated with progression to surgery. These findings represent important factors for patient counseling and risk modeling in FAI.

中文翻译：

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与有症状的股骨髋臼撞击患者对侧髋关节疾病进展相关的因素：至少 5 年的分析

背景：

股骨髋臼撞击（FAI）是髋关节骨关节炎最常见的原因之一，但控制疾病进展的因素却知之甚少。

目的：

调查 FAI 患者对侧髋部初始和后续症状的发生率，并确定对侧髋部疾病进展（症状发展和手术干预）的预测因子。

学习规划：

队列研究；证据水平，2。

方法：

这项前瞻性研究包括对 179 名接受 FAI 手术的患者的对侧髋关节进行至少 5 年的随访。监测症状（中度疼痛）和手术进展。单变量和多变量分析比较了有症状患者和无症状患者的患者特异性和影像学特征，以确定与疾病进展相关的因素。

结果：

总共对 150 名患者（84% 的随访）进行了平均 7.1 年的随访（范围为 5-11 年）。这些患者中有 39 名 (26% [39/150]) 在初始评估时出现对侧髋关节症状。在最初评估时没有对侧髋关节症状的患者中，32% (36/111) 在最近的随访中出现了对侧髋关节症状。在研究期间出现症状的人具有较低的前后头颈偏移比（0.153 vs 0.165；P = 0.005），90°屈曲时的总旋转弧度减少（39.9° vs 51.1°；P = 0.005） ，并且在 90° 屈曲时外旋减少（28.6° vs 37.1°；P= .003) 与从未出现症状的人相比。这些组之间的年龄、性别、体重指数、α角、侧向中心边缘角、屈曲内旋和加州大学洛杉矶分校 (UCLA) 的活动评分相似。初始评估时有对侧症状的患者以 41% (16/39) 的比率进展到对侧手术，而在研究期间出现对侧症状的患者进展为对侧手术的比例为 28% (10/36)。在具有对侧髋关节症状（最初出现或在研究期间出现）的患者中，年龄较小（24.6 对 34.1 岁；P< .001) 和基线 UCLA 活动评分≥9 (P = .003) 与手术进展相关。通过 Kaplan-Meier 分析，64%、54% 和 48% 的患者在 2、5 和 10 年时仍然没有对侧髋关节症状。

结论：

在平均 7.1 年的随访中，大约 50% 的 FAI 患者对侧髋关节出现明显症状。FAI 疾病进展（症状发展和手术干预）与髋关节旋转弧度减少、外旋减少和头颈偏移比降低有关。在有症状的患者中，年龄较小和 UCLA 活动评分≥9 与进展为手术相关。这些发现代表了 FAI 患者咨询和风险建模的重要因素。