作者：Joel Wells,Michael Millis, Young-Jo Kim, Evgeny Bulat, Patricia Miller, Travis Matheney

作者单位:Department of Orthopedic Surgery, Children's Hospital Boston, Harvard MedicalSchool, 300 Longwood Avenue, Boston, MA, 02115, USA.

译者：陶可(北京大学人民医院骨关节科)

摘要

背景：伯尔尼髋臼周围截骨术(PAO) 仍然是治疗有症状的发育性髋关节发育不良的常用非关节成形术(即全髋人工关节置换术, THA)选择，但很少有长期随访研究评估 PAO 后的临床结果。

问题/目的：(1)PAO术后髋关节的长期存活率是多少? (2)14年前患有PAO的患者的验证结果评分是多少? (3) 哪些因素与长期失效有关?

方法：1991年5月至1998年9月期间，由一名骨科医生对158名发育性髋关节发育不良(133名患者)进行了PAO治疗。其中，37髋(34名患者 [26%])失访;另有7名患者(5% [8 髋])在过去5年中没有出现过。在平均18年(范围，14-22年)时对121髋(99名患者)进行回顾性评估。以全髋关节置换术 (THA) 为终点，使用Kaplan-Meier分析评估存活率。使用UCLA (The University of California, Los Angeles) 活动评分、改良Harris髋关节评分、WOMAC (The Western Ontario andMcMaster Universities Osteoarthritis Index)以及髋关节残疾和骨关节炎结果评分 (HOOS) 评估髋关节的活动、疼痛和一般健康状况。失败定义为WOMAC疼痛分量表评分≥10或已接受THA。髋关节分为三组：无症状(在任何时间点均未达到任何失败标准)、有症状(在之前或最近的随访中符合WOMAC疼痛失败标准)和置换(已接受THA)。使用一般估计方程方法的多元逻辑回归模型用于评估与失败相关的因素。

结果：以THA为终点的Kaplan-Meier分析显示，18年的生存率(95%置信区间[CI])为74%(66%-83%)。 26髋(21%)在手术后平均9±5年内接受了THA。 64髋 (53%) 在最近的随访中保持无症状且不符合任何失败标准。基于WOMAC疼痛评分≥10且在最近一次随访中的20例中的均数±SD为11±4，31髋 (26%) 有症状且被视为PAO手术治疗失败。尽管有些最初因疼痛失败，但他们最近的WOMAC评分可能<10。在因疼痛早期失败的16个有症状的髋关节中(在先前的研究中报告WOMAC疼痛分量表评分≥10)，2个失访，2个在16年和17年时接受了THA，其中4人在最近一次随访时仍因疼痛失败，其余8人在最近一次随访时WOMAC疼痛评分<10。无症状髋关节报告了更好的 UCLA 活动评分(无症状：均数 ±SD，7±2;有症状：6±2，p = 0.001)，改良 Harris 髋关节评分(疼痛、功能和活动部分;无症状：80±11;有症状： 50±15, p<0.001)、WOMAC(无症状：2±2，有症状：11±4，p<0.001)和 HOOS(无症状：87±11，有症状：52±20，p<0.001)与有症状相比长期随访中髋关节。 PAO时年龄超过25岁(有症状：优势比 [OR]，3.6;95%CI，1.3-9.8;p=0.01;置换：OR，8.9;95%CI，2.6-30.9;p<0.001) 和术前关节间隙宽度≤2mm(置换OR，0.3;95%CI，0.12-0.71;p=0.007)或≥5mm(置换 ：OR，0.121;95% CI，0.03-0.56;p=0.007) 与长期失败相关，同时由于术前关节形合度较差或一般。

结论：这项研究证明了伯尔尼PAO在长期随访中的持久性。在一部分患者中，随着时间的推移进展为失败。进展为THA或更严重症状的因素包括年龄超过25岁、术前髋关节形合度较差或一般，以及术前关节间隙宽度小于2毫米或大于5毫米。未来的研究应侧重于评估我们在研究中确定的两个失败组：那些早期失败并继续进行THA的组和那些在长期随访中出现症状的组。

图1 研究人群的流程图。

表1. 患者报告的结果数值 HOOS = 髋关节残疾和骨关节炎结果评分。

图2Kaplan-Meier 生存曲线，显示PAO后保留的髋关节百分比。

表2. 按结果分类的患者和髋关节的特征

* 66名受试者的BMI和抑郁数据; p值对应于无症状和有症状髋关节之间的比较; p值对应于无症状髋关节和髋关节置换之间的比较; BMI=体重指数; LCEA=外侧中心边缘角; ACEA=前中心边缘角。

表3. 最近一次随访时患者报告的结果(N = 82 名患者)

表4. 最终多项式模型中包含的变量的调整分析OR=优势比; CI=置信区间; JSW=关节间隙宽度。

表5. PAO术后结果的预测算法

图3 这是一个直方图，展示了未进行髋关节置换术的髋关节的 WOMAC 疼痛评分分布。

讨论

报告PAO术后的长期结果很少，据我们所知，我们的结果(随访病例数)是最大的;在其中，我们旨在发现并分析与长期失败相关的因素。我们的数据表明，理想的术前患者标准是年龄小于25岁，具有足够的关节间隙宽度和良好的髋关节形合度(PAO截骨术后保髋生存期会最长)。

这项研究有局限性。首先，这项回顾性研究代表了一位骨科医生在大手术量中心的经验。这个作者(MM)是技术大师，作为单一骨科医生系列病例，这是一个优点和缺点。结果可能不代表小规模外科医生或中心，这可能会限制推广结果的能力。在类似的大容量保髋中心，这项研究可能有助于指导骨外科医生。其次，术中头颈部偏移未进行评估或校正，并且在初始研究手术时间段内未分析术后头颈部偏移的 X 线片。Albers等人在他们为期10年的回顾性研究中，发现撞击会对结果产生不利影响。不幸的是，我们无法评论医源性股骨髋臼撞击作为失败风险因素的可能性。

我们还注意到，这是一个没有对照组的回顾性病例系列。这种类型的研究可能会受到各种偏见的影响。我们的纳入标准减轻了选择偏差，该标准定义明确，并且由于这些标准，这些结果仅适用于没有既往髋部创伤或神经肌肉或结缔组织疾病的有症状的DDH患者。 37 髋(34名患者 [26%])失访，尽管他们的术前特征相似，但无法获得这些患者的术后生存率和患者报告的结果。失访患者允许转移偏倚，因此这些结果代表了最好的情况，因为我们无法报告那些未考虑的结果。此外，在过去5年内没有在我们机构就诊的7名患者中有8名髋关节。我们保留了这些患者并将他们纳入分析，因为我们的目标是回顾PAO后15年的情况。我们必须认识到，没有可用的比较术前结果测量方法，这也是本研究的局限性。另一个限制是，64个无症状髋关节中只有35个(55%) 和31个有症状髋关节中的19个 (61%) 可以获得长期术后X线片。尽管射线照相数据不是失败标准的一部分，但长期术后射线照相对于评估是有用的。尽管分析中包括了双侧髋关节，但我们能够针对相同受试者的相关测量引入的任何潜在偏差进行调整。此外，当将GEE调整分析与标准的一般线性建模分析进行比较时，GEE模型提供了更准确的效应估计值和更窄的CI。因此，我们可以假设通过包括双侧髋关节和髋关节在我们的研究中引入的偏差很小，这是长期PAO随访的独特案例。

从历史上看，只有转换为THA才被认为是失败的。在年轻的成年人口中，这不是PAO失败的良好标志。我们已经表明，尽管没有接受THA，一些患者仍报告疼痛和生活质量下降。因此，需要患者报告的结果来正确评估患者的疼痛和功能。本次和我们的初始报告中使用的主要结果评分和失败决定因素是WOMAC 疼痛分量表评分(图 3)。WOMAC疼痛分量表大于或等于10已被证明是评估髋骨关节炎，以及那些接受非关节置换髋关节手术的患者的临床准确标准。在选择主观结果测量时，患者可接受的症状状态和最小的临床重要改善是重要因素。该WOMAC疼痛临界值在这方面很有用，可以正确识别满意和不满意的受试者。我们已经表明，在所有使用的结果测量中，有症状的髋关节(因WOMAC 疼痛评分≥10 而失败的那些)报告的疼痛、活动和生活质量结果比无症状髋关节显着(p<0.001)更差。

DDH是一种已知的疼痛原因，并且是年轻成年人群发病的重要原因。很少有研究报告PAO后活动相关和生活质量的结果。Beaule等人在他们2014年髋关节发育不良系列报告中，UCLA术前评分为5.3，术后中位随访5年时评分提高至6.6。van Bergayk和Garbuz报告了对22名患者进行2年随访的小型队列的生活质量和运动特异性结果测量。他们发现短期随访中WOMAC和SF-36评分有临床意义的改善。在我们的研究中，无症状髋关节的UCLA术后平均长期活动评分为7±2，有症状臀部为6±2。这些结果与Beaule等人的以及van Bergayk和Garbuz的相当。我们能够在长期随访中表明，无论是无症状还是有症状，接受PAO的患者都能够保持规律的活动。

Steppacher等人报告了58髋的平均20年随访。41个髋关节 (60%) 保留下来并且没有接受 THA，8个保留的髋关节 (20%) 根据他们的平均 Merle d’Aubigne 评分被分级为一般或差。几个变量被确定为预后。其中包括年龄大于30岁、术前Merle d'Aubigne和Postel评分较低、术前前方撞击试验阳性、术前跛行、根据Tönnis分级的术前关节病更大，以及术后挤压指数。我们的研究发现，无论是WOMAC疼痛分量表评分≥10还是转换为THA，年龄超过25岁都是失败的独立预测因素。除年龄外，术前关节间隙和术前关节一致性进一步加强了预测模型。我们无法找到任何作为失败独立预测因素的术后特征。我们构建了一个简化表，以方便参考，以显示PAO后的长期预后(表 5)。在PAO时年龄小于等于25岁的患者具有良好或极好的关节一致性，并且最小关节间隙宽度在2到5毫米之间，无症状的概率为81%，有症状的概率为15%，出现症状的概率为5%。在平均18年的随访中被置换。我们的分析可以帮助指导外科医生选择可能从PAO中受益的患者，从而帮助改善结果。

总之，我们发现大多数髋关节(77%) 在平均18年时得以保留并且没有接受过THA。一部分患者在长期随访中被确定为具有更差的结果，并被归类为有症状的 (26%)。确定了有症状或置换结果的三个因素：术前年龄大于25岁，术前最小关节间隙宽度小于2毫米或大于5毫米，以及术前髋关节形合度差或一般。基于这些发现，我们认为，正确选择患者对于优化可能受益于PAO的患者的结果以及确定可以更好地接受THA治疗的患者至关重要。重要的是要了解，虽然我们发现年龄超过25岁与失败相关，但不应将其用作手术的年龄临界值，因为老年患者可能会因其他有利的术前变量而受益于PAO手术。未来的研究应侧重于尽管已确定有利因素，但仍接受早期置换或有髋关节症状的患者。这些患者可能具有尚不明显的其他不良预后特征。

文献出处：JoelWells, Michael Millis, Young-Jo Kim, Evgeny Bulat, Patricia Miller, TravisMatheney. Survivorship of the Bernese Periacetabular Osteotomy: What Factorsare Associated with Long-term Failure? Clin Orthop Relat Res. 2017Feb;475(2):396-405. doi: 10.1007/s11999-016-4887-z.

原文：

Survivorship of theBernese Periacetabular Osteotomy: What Factors are Associated with Long-termFailure?

Abstract

Background: TheBernese periacetabular osteotomy (PAO) continues to be a commonly performednonarthroplasty option to treat symptomatic developmental hip dysplasia, butthere are few long-term followup studies evaluating results after PAO.

Questions/purposes:(1) What is the long-term survivorship of the hip after PAO? (2) What were thevalidated outcomes scores among patients who had PAO more than 14 years ago?(3) What factors are associated with long-term failure?

Methods: One hundredfifty-eight dysplastic hips (133 patients) underwent PAO between May 1991 andSeptember 1998 by a single surgeon. Of those, 37 hips (34 patients [26%]) werelost to followup; an additional seven patients (5% [eight hips]) had not beenseen in the last 5 years. The 121 hips (in 99 patients) were retrospectivelyevaluated at a mean of 18 years (range, 14-22 years). Survivorship was assessedusing Kaplan-Meier analysis with total hip arthroplasty (THA) as the endpoint.Hips were evaluated for activity, pain, and general health using the UCLA ActivityScore, modified Harris hip score, WOMAC, and Hip disability and OsteoarthritisOutcome Score (HOOS). Failure was defined as a WOMAC pain subscale score ≥ 10or having undergone THA. Hips were divided into three groups: asymptomatic (didnot meet any failure criteria at any point in time), symptomatic (met WOMACpain failure criteria at previous or most recent followup), and replaced(having undergone THA). A multinomial logistic regression model using a generalestimating equations approach was used to assess factors associated withfailure.

Results: Kaplan-Meieranalysis with THA as the endpoint revealed a survival rate (95% confidenceinterval [CI]) of 74% (66%-83%) at 18 years. Twenty-six hips (21%) underwentTHA at an average of 9 ± 5 years from the surgery. Sixty-four hips (53%)remained asymptomatic and did not meet any failure criteria at most recentfollowup. Thirty-one hips (26%) were symptomatic and considered failed based ona WOMAC pain score of ≥ 10 with a mean ± SD of 11 ± 4 out of 20 at most recentfollowup. Although some failed initially by pain, their most recent WOMAC scoremay have been < 10. Of the 16 symptomatic hips that failed early by pain(reported a WOMAC pain subscale score ≥ 10 in the prior study), two were lostto followup, two underwent THA at 16 and 17 years, four still failed because ofpain at most recent followup, and the remaining eight had WOMAC pain scores< 10 at most recent followup. Asymptomatic hips reported better UCLAActivity Scores (asymptomatic: mean ± SD, 7 ± 2; symptomatic: 6 ± 2, p =0.001), modified Harris hip scores (pain, function, and activity sections;asymptomatic: 80 ± 11; symptomatic: 50 ± 15, p < 0.001), WOMAC(asymptomatic: 2 ± 2, symptomatic: 11 ± 4, p < 0.001), and HOOS(asymptomatic: 87 ± 11, symptomatic: 52 ± 20, p < 0.001) compared withsymptomatic hips at long-term followup. Age older than 25 years at the time ofPAO (symptomatic: odds ratio [OR], 3.6; 95% CI, 1.3-9.8; p = 0.01; replaced:OR, 8.9; 95% CI, 2.6-30.9; p < 0.001) and a preoperative joint space width ≤2 mm (replaced: OR, 0.3; 95% CI, 0.12-0.71; p = 0.007) or ≥ 5 mm (replaced: OR,0.121; 95% CI, 0.03-0.56; p = 0.007) were associated with long-term failurewhile controlling for poor or fair preoperative joint congruency.

Conclusions: Thisstudy demonstrates the durability of the Bernese PAO at long-term followup. Ina subset of patients, there was progression to failure over time. Factors ofprogression to THA or more severe symptoms include age older than 25 years,poor or fair preoperative hip congruency, and a preoperative joint space widththat is less than 2 mm or more than 5 mm. Future studies should focus onevaluating the two failure groups that we have identified in our study: thosethat failed early and went on to THA and those that are symptomatic atlong-term followup.

Few long-termoutcomes after PAO have been reported and to our knowledge ours is among thelargest; in it, we aimed to define and analyze factors associated with longtermfailure [2, 7, 17, 21, 28, 31, 33, 40, 43]. Our data suggest that the idealcandidate is younger than 25 years of age with adequate joint space width andgood hip congruency.

This study haslimitations. First, this retrospective study represents a single surgeon’sexperience in a high-volume center. This author (MM) is a master technician andas a single-surgeon series, this is a strength and weakness. The results maynot be representative of low-volume surgeons or centers, which may limit theability to generalize the results. In similar high-volume joint preservationcenters, this study may help to guide surgeons. Second, intraoperative head andneck offset was not evaluated nor corrected, and postoperative radiographs werenot analyzed for head and neck offset during the initial study surgical timeperiod. Albers et al. [2], in their 10-year retrospective study, found thatimpingement adversely affected outcome. Unfortunately, we are unable to commenton the possibility of iatrogenic femoroacetabular impingement being a riskfactor for failure.

We also note thatthis is a retrospective case series without a control group. This type of studycan suffer from a variety of biases. Selection bias was mitigated by ourinclusion criteria, which was well defined and because of such criteria, theseresults only apply to patients with symptomatic DDH without prior hip trauma orneuromuscular or connective tissue disease. Thirty-seven hips (34 patients[26%]) were lost to followup and although their preoperative characteristicswere similar, postoperative survivorship and patient-reported outcomes were notavailable for these patients. Patients lost to followup allow for transfer biasand therefore these results represent a best case scenario because we are notable to report on the outcomes of those not accounted for. Also, there wereeight hips in seven patients who had not been seen at our institution withinthe past 5 years. We kept these patients and included them in the analysisbecause our goal was to review a 15-year snapshot post-PAO. We must recognizethat there were no comparative preoperative outcome measures available and thisis also a limitation to this study. Another limitation is that long-termpostoperative radiographs were available for only 35 (55%) of the 64asymptomatic hips and 19 (61%) of the 31 symptomatic hips. Althoughradiographic data were not part of the failure criteria, long-termpostoperative radiographs would have been useful for evaluation. Althoughbilateral hips were included in the analyses, we were able to adjust for anypotential bias introduced by correlated measurements on the same subjects. Inaddition, when comparing the GEE-adjusted analysis with a standard generallinear modeling analysis, the GEE model provided more accurate effect estimateswith narrower CIs. Thus, we can assume that little bias was introduced byincluding bilateral hips and the hips in our study present unique cases oflong-term PAO followup.

Historically, onlyconversion to a THA has been considered a failure [2, 8, 21, 40]. In a youngadult population, this is not a good marker of PAO failure. We have shown that,despite not undergoing THA, some patients report pain and a diminished qualityof life. Therefore, patient reported outcomes are required to properly assesspatient pain and function. The main outcome score and determinant of failureused in this and our initial report was the WOMAC pain subscale score (Fig. 3).A WOMAC pain subscale greater than or equal to 10 has been shown to be aclinically accurate criterion in evaluating hip osteoarthritis as well as thosepatients undergoing nonarthroplasty hip surgery [9, 13, 25, 27, 39].Patient-acceptable symptom state and minimal clinically important improvementare important factors when choosing a subjective outcome measure. This WOMACpain cutoff is useful in this regard and can correctly identify subjects whoare satisfied and unsatisfied [13]. We have shown that symptomatic hips (thosethat failed as a result of WOMAC pain score ≥10) reported significantly(p<0.001) worse pain, activity, and quality-of-life outcomes thanasymptomatic hips in all outcome measures used.

DDH is a known causeof pain and is a substantial cause of morbidity in the young adult population[2, 5, 17]. Few studies have reported on activity-related and quality-of-lifeoutcomes after PAO. Beaule´ et al. [5] in their 2014 series on dysplastic hipsreported a preoperative UCLA score of 5.3 with an improvement to 6.6 at amedian of 5 years postoperative followup. van Bergayk and Garbuz [44] reportedon quality of life and sports-specific outcome measures on a small cohort of 22patients with followup of 2 years. They found a clinically importantimprovement in WOMAC and SF-36 scores at short-term followup. In our study, themean long-term postoperative UCLA Activity Score was 7 ± 2 for the asymptomatichips and 6 ± 2 for symptomatic hips. These results are comparable to Beaule´ etal.’s [5] and van Bergayk and Garbuz’ [44]. We are able to show at long-termfollowup that patients undergoing PAO whether asymptomatic or symptomatic areable to remain regularly active.

Steppacher et al.[40] reported on the mean 20-year followup of 58 hips. Forty-one hips (60%)remained preserved and did not undergo THA, and eight hips (20%) that remainedpreserved were graded as fair or poor according to their mean Merle d’Aubignescores. Several variables were identified as prognostic. These included ageolder than 30 years, lower preoperative Merle d’Aubigne and Postel score,positive preoperative anterior impingement test, preoperative limp, greaterpreoperative arthrosis according to Tönnis grade, and postoperative extrusionindex [40]. Our study found that age older than 25 years is an independentpredictor of failure whether by results of WOMAC pain subscale score C 10 orconversion to THA. In addition to age, preoperative joint space andpreoperative joint congruency further strengthened a prediction model. We wereunable to find any postoperative characteristics that were independentpredictors of failure. We constructed a simplified table for easy reference todisplay the long-term prognosis after PAO (Table 5). A patient who is at most25 years old at PAO has good or excellent joint congruency and has a minimumjoint space width between 2 and 5 mm has an 81% probability of being asymptomatic,15% probability of being symptomatic, and 5% probability of being replaced atan average of 18 years of followup. Our analysis can help guide surgeons tochoose patients who might benefit from PAO and thus help improve outcomes.

In summary, we foundthat the majority of hips (77%) at an average of 18 years are preserved and hadnot undergone THA. A subset of patients was identified as having worse outcomemeasures at long-term followup and were classified as symptomatic (26%). Threefactors of having a symptomatic or replaced outcome were identified:preoperative age older than 25 years, preoperative minimum joint space widthless than 2 mm or greater than 5 mm, and a poor or fair preoperative hipcongruency. Based on these findings, we believe that proper selection ofpatients is crucial in optimizing outcomes for patients who may benefit fromPAO as well as identifying patients who would be better treated with THA. It isimportant to understand that although we found age older than 25 years to beassociated with failure, it should not be used as an age cutoff for surgery,because older patients may benefit from PAO by virtue of other favorablepreoperative variables. Future studies should be focused on patients whoundergo early replacement or have symptomatic hips despite the identifiedfavorable factors. These patients may have additional poor prognostic featuresthat are not yet apparent.