Nwachukwu Benedict U, Chang Brenda, Fields Kara, Rebolledo Brian J, Nawabi Danyal H, Kelly Bryan T, Ranawat Anil S
Hospital for Special Surgery, New York, New York, USA.
Am J Sports Med. 2017 May;45(6):1297-1303. doi: 10.1177/0363546516687541. Epub 2017 Feb 1.
The minimal clinically important difference (MCID) has been defined in orthopaedics and is the smallest change that a patient considers meaningful. Less is known about improvements that the patient perceives as clinically considerable, or the substantial clinical benefit (SCB). For the young, highly functioning patient cohort with femoroacetabular impingement (FAI), the SCB is an important measure of clinical success.
To derive the SCB for FAI treatment and identify outcome score thresholds and patient variables predictive of the SCB.
Cohort study (diagnosis); Level of evidence, 2.
The modified Harris Hip Score (mHHS), the Hip Outcome Score activities of daily living (HOS-ADL) and sport (HOS-Sport) subscales, and the international Hip Outcome Tool (iHOT-33) were prospectively administered to 364 patients with a minimum 1-year follow-up. At 1 year postoperatively, patients graded their hip function based on several anchor responses such as "no change" and "much improved." The SCB was defined as the change on each outcome tool that equated to the difference between "no change" and "much improved" on the health transition question. Receiver operating characteristic analysis with area under the curve (AUC) was used to identify optimal values that were most representative of the SCB. Multivariable analysis identified patient variables predictive of the SCB.
The net change in outcome scores corresponding to the SCB for the mHHS, HOS-ADL, HOS-Sport, and iHOT-33 was 19.8, 10.0, 29.9, and 24.5, respectively. The following postoperative outcome scores demonstrated excellent distinction (AUC >0.8) between "no change" and "much improved" and thus were considered absolute values for the postoperative SCB: 82.5 (mHHS), 93.3 (HOS-ADL), 84.4 (HOS-Sport), and 63.5 (iHOT-33). Preoperative scores on the HOS-ADL (83.3) and HOS-Sport (50.0) were significant threshold cutoffs, above which attaining the SCB became less likely. Younger age and lower Outerbridge grade were predictive of achieving the SCB.
The SCB has not been previously defined in the hip preservation literature and is complementary to the MCID as the upper bound for clinically significant improvement. We identified predictive preoperative and diagnostic postoperative outcome scores for the SCB that can be used to manage patient expectations and grade outcomes. These findings are objective criteria for defining clinical success after arthroscopic FAI treatment.
最小临床重要差异（MCID）已在骨科领域得到定义，是患者认为有意义的最小变化。对于患者认为具有临床意义的改善或显著临床获益（SCB），人们了解较少。对于年轻、功能良好的股骨髋臼撞击症（FAI）患者群体而言，SCB是衡量临床成功的一项重要指标。
得出FAI治疗的SCB，并确定结果评分阈值以及预测SCB的患者变量。
队列研究（诊断）；证据等级，2级。
对364例患者前瞻性应用改良Harris髋关节评分（mHHS）、髋关节功能评分日常生活活动（HOS-ADL）和运动（HOS-Sport）子量表以及国际髋关节功能评估工具（iHOT-33），并进行至少1年的随访。术后1年，患者根据“无变化”和“改善很多”等多项关键回答对其髋关节功能进行评分。SCB定义为每种结果工具上的变化，该变化等同于健康转变问题中“无变化”和“改善很多”之间的差异。采用曲线下面积（AUC）的受试者工作特征分析来确定最能代表SCB的最佳值。多变量分析确定了预测SCB的患者变量。
mHHS、HOS-ADL、HOS-Sport和iHOT-33对应SCB的结果评分净变化分别为19.8、10.0、29.9和24.5。以下术后结果评分在“无变化”和“改善很多”之间表现出出色的区分度（AUC>0.8），因此被视为术后SCB的绝对值：82.5（mHHS）、93.3（HOS-ADL）、84.4（HOS-Sport）和63.5（iHOT-33）。HOS-ADL（83.3）和HOS-Sport（50.0）的术前评分是显著的阈值界限，高于此界限则达到SCB的可能性降低。年龄较小和Outerbridge分级较低可预测达到SCB。
SCB此前在保髋文献中尚未得到定义，作为临床显著改善的上限，它是对MCID的补充。我们确定了SCB的术前预测性和术后诊断性结果评分，可用于管理患者期望和对结果进行分级。这些发现是定义关节镜下FAI治疗后临床成功的客观标准。
