Nwachukwu Benedict U, Fields Kara, Chang Brenda, Nawabi Danyal H, Kelly Bryan T, Ranawat Anil S
Hospital for Special Surgery, New York, New York, USA.
Am J Sports Med. 2017 Mar;45(3):612-619. doi: 10.1177/0363546516669325. Epub 2016 Oct 23.
There is increasing interest in defining meaningful improvement in patient-reported outcomes. Knowledge of the thresholds and determinants for successful femoroacetabular impingement (FAI) outcomes is evolving.
To define preoperative outcome score thresholds and determine clinical/demographic patient factors predictive for achieving the minimal clinically important difference (MCID) after arthroscopic FAI surgery.
Cohort study (diagnosis); Level of evidence, 2.
A prospective institutional hip preservation registry was reviewed to identify patients undergoing arthroscopic FAI surgery. The modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS), and the international Hip Outcome Tool (iHOT-33) were administered at baseline and 1 year postoperatively. The MCID was calculated using a distribution-based method. Receiver operating characteristic (ROC) analysis was used to calculate cohort-based threshold values predictive of achieving the MCID. The area under the curve (AUC) was used to define predictive ability, with AUC >0.7 considered acceptably predictive. Multivariable analysis identified patient factors associated with achieving the MCID. Sensitivity analysis was performed to derive the MCID by an alternative anchor-based method.
There were 364 patients (mean [±SD] age, 32.5 ± 10.3 years), and 57.1% were female. The MCID for the mHHS, HOS-Activities of Daily Living (HOS-ADL), HOS-Sports, and iHOT-33 was 8.2, 8.3, 14.5, and 12.1, respectively. ROC analysis findings (threshold, percentage achieving the MCID, and strength of association) for these tools were as follows: mHHS (60.5, 77.2%, and 0.68, respectively), HOS-ADL (83.3, 68.1%, and 0.85, respectively), HOS-Sports (58.3, 65.9%, and 0.76, respectively), and iHOT-33 (53.9, 81.9%, and 0.65, respectively). The likelihood for achieving the MCID significantly declined above these thresholds. In multivariable analysis, a higher sagittal center-edge angle (CEA) (odds ratio [OR], 1.04; 95% CI, 1.01-1.08) was a positive predictor of achieving the MCID on the iHOT-33, while a higher Outerbridge grade for the acetabulum was a negative predictor (OR, 0.56; 95% CI, 0.32-0.99) on the mHHS. Sensitivity analysis confirmed these variables and identified relative femoral retroversion as another negative predictor (OR, 0.40; 95% CI, 0.17-0.94).
The HOS had excellent predictive ability for identifying patient thresholds of achieving the MCID; patients with preoperative scores below identified thresholds were most likely to achieve the MCID. Additionally, anterior acetabular undercoverage, chondral injuries, and relative femoral retroversion were clinically significant negative modifiers of outcomes. These findings have implications for managing preoperative expectations of FAI surgery.
人们对定义患者报告结局的有意义改善越来越感兴趣。关于成功的股骨髋臼撞击症（FAI）结局的阈值和决定因素的认识正在不断发展。
确定术前结局评分阈值，并确定预测关节镜下FAI手术后达到最小临床重要差异（MCID）的临床/人口统计学患者因素。
队列研究（诊断）；证据等级，2级。
回顾一项前瞻性机构性髋关节保留登记处，以识别接受关节镜下FAI手术的患者。在基线和术后1年采用改良Harris髋关节评分（mHHS）、髋关节结局评分（HOS）和国际髋关节结局工具（iHOT-33）。使用基于分布的方法计算MCID。采用受试者操作特征（ROC）分析来计算预测达到MCID的基于队列的阈值。曲线下面积（AUC）用于定义预测能力，AUC>0.7被认为具有可接受的预测性。多变量分析确定与达到MCID相关的患者因素。进行敏感性分析，通过另一种基于锚定的方法得出MCID。
共有364例患者（平均[±标准差]年龄，32.5±10.3岁），57.1%为女性。mHHS、HOS-日常生活活动（HOS-ADL）、HOS-运动和iHOT-33的MCID分别为8.2、8.3、14.5和12.1。这些工具的ROC分析结果（阈值、达到MCID的百分比和关联强度）如下：mHHS（分别为60.5、77.2%和0.68）、HOS-ADL（分别为83.3、68.1%和0.85）、HOS-运动（分别为58.3、65.9%和0.76）和iHOT-33（分别为53.9、81.9%和0.65）。高于这些阈值时，达到MCID的可能性显著下降。在多变量分析中，较高的矢状中心边缘角（CEA）（比值比[OR]，1.04；95%可信区间，1.01-1.08）是iHOT-33达到MCID的阳性预测因素，而髋臼较高的Outerbridge分级是mHHS的阴性预测因素（OR，0.56；95%可信区间，0.32-0.99）。敏感性分析证实了这些变量，并确定相对股骨后倾是另一个阴性预测因素（OR，0.40；95%可信区间，0.17-0.94）。
HOS在识别达到MCID的患者阈值方面具有出色的预测能力；术前评分低于确定阈值的患者最有可能达到MCID。此外，髋臼前侧覆盖不足、软骨损伤和相对股骨后倾是临床上重要的结局负面修饰因素。这些发现对管理FAI手术的术前预期具有重要意义。
