基于X线片建立股骨头坏死新分型体系的临床意义

目的观察围塌陷期股骨头坏死在影像学上的表现形式,进行分类总结。 方法选择在广州中医药大学第一附属医院确诊为围塌陷期股骨头坏死且有完整影像资料的患者,排除髋部有先天畸形或有影响髋关节功能的疾病等。在双侧髋关节标准正位片上观察股骨头坏死硬化带的形态及其与髋臼"眉弓"的对应关系,在双侧髋关节蛙式侧位片上观察股骨头坏死硬化带的形态及其与股骨头前外侧柱的对应关系,根据不同表现形式进行分类。 结果共纳入266例435髋,在双侧髋关节标准正位片上观察到6种股骨头坏死硬化带的表现形式,分别是A型(硬化带边缘在眉弓内侧1/3以内)19(4.4%),B型(硬化带边缘在"眉弓"中间1/3内)89髋(20.1%),C1型(硬化带边缘在眉弓外侧1/3内)155髋(35.6%),C2型(硬化带边缘超过髋臼外侧缘)87髋(20.0%),D1型(硬化带呈环形,位于股骨头中心)47髋(10.8%),D2型(硬化带呈环形,位于股骨头负重区软骨下骨板)38髋(8.7%)。在双侧髋关节蛙式侧位片上观察到5种股骨头坏死硬化带的表现形式,分别是1型(硬化带边缘位于股骨头后内侧柱或中央柱)3髋(0.7%),2型(硬化带边缘位于股骨头后内侧柱或中央柱,深部累及前外侧柱)51髋(11.7%),3型(硬化带边缘位于股骨头前外侧柱)316髋(72.6%),4型(硬化带呈环形,位于股骨头中心)32髋(7.4%),5型(硬化带呈环形,位于股骨头负重区软骨下骨板)33髋(7.6%)。总结出435髋共有19种匹配结果,结合纳入髋数的塌陷率,初步确定蛙位3型匹配正位B、C1、C2和D2时,需要采取外科干预。 结论根据股骨头坏死硬化带在影像学上的表现形式建立正位和蛙式侧位分型,充分考虑股骨头外侧柱和前外侧柱的坏死累及情况,更能反映疾病的本质,为临床诊断、治疗和预后判断提供参考。     

基于三柱结构分型股骨头坏死的有限元研究

[目的]本研究基于三柱结构中日友好医院(CJFH)分型对股骨头进行三维有限元分析,研究不同坏死体积的股骨头受力情况,为临床保髋治疗提供理论依据。[方法]选取正常25岁男性青年髋关节CT片股骨头有限元模型,按CJFH分型中的每一型建立占股骨头总体积5%,15%,30%,50%的坏死体积模型,划分网格后进行力学分析。[结果]根据股骨头位移云图及数据,坏死组织的位移偏大,位移峰值均处在负重区的坏死组织上,不同坏死体积坏死带的力学分布可以发现,在坏死体积15%的情况下,压力最高峰值未达到塌陷压力,当坏死体积达到30%时,L2型及L3型塌陷风险极高,L3型以有超过50%坏死区域应力大于塌陷应力。[结论]坏死组织体积越大,位移越大,越容易塌陷,当涉及外侧柱的坏死体积达30%时,塌陷概率大大增加。     

基于中日友好医院分型的股骨头坏死阶梯化保髋治疗经验总结

目的总结基于中日友好医院分型(CJFH分型)的股骨头坏死阶梯化保髋治疗经验,以供临床参考。方法广泛查阅相关文献,并结合本研究小组股骨头坏死保髋治疗28年临床经验,总结基于CJFH分型的股骨头坏死阶梯化保髋治疗方案。结果 CJFH分型将股骨头坏死分为M型、C型、L型,其中L型又分为L1、L2、L3亚型,本研究小组基于该分型标准制定了阶梯化保髋治疗方案。其中,M型一般坏死范围小、坏死部位在内侧非负重区,首选保守治疗。C型一般坏死范围小、坏死部位在外侧负重区,宜用微创死骨清除打压植骨异体腓骨棒支撑术。L型中,L1型髋关节外展位X线片显示正常骨范围未超过1/3者,优先考虑外科脱位头颈开窗死骨清理打压植骨术;正常骨范围超过1/3者,优先考虑经转子间弧形内翻截骨术;L2型可选择外科脱位股骨颈基底部旋转截骨术;L3型一般选择人工全髋关节置换术。结论基于CJFH分型的股骨头坏死阶梯化保髋治疗方案已取得一定疗效,远期效果有待进一步观察。     

基于中日友好医院分型的股骨头坏死保髋手术疗效的影响因素分析

目的探讨基于中日友好医院(China-Japan Friendship Hospital,CJFH)分型的保髋手术疗效的影响因素。方法2012年6月至2016年9月接受保髋手术治疗的非创伤性股骨头坏死患者325例432髋。依据CJFH分型行髓芯减压自体骨髓单个核细胞移植141髋(髓芯减压组)和头颈部开窗减压病灶清除植骨术291髋(开窗减压组)。采用Harris髋关节功能评分评估临床疗效,摄X线片观察坏死修复、股骨头塌陷及关节退变。临床失败定义为末次随访时Harris评分较术前评级降低和(或)影像学上股骨头塌陷进展(ARCO分期增加)。终点事件为疼痛明显加重、Harris评分为差(<70分)和(或)股骨头进行性塌陷。采用Cox比例回归模型分析临床失败的危险因素。结果髓芯减压组67髋临床失败(47.5%,67/141),其中CJFH分型C+M型3髋(13.0%,3/23)、L1型24髋(38.1%,24/63)、L2型14髋(82.4%,14/17)、L3型26髋(68.4%,26/38)。开窗减压组106髋临床失败(36.4%,106/291),C+M型1髋(33.3%,1/3)、L1型41髋(31.3%,41/131)、L2型22髋(84.6%,22/26)、L3型42髋(32.1%,42/131)。髓芯减压组中不同年龄(χ2=3.887,P=0.049)、不同术前CJFH分型(χ2=40.943,P=0.000)的临床失败率的差异有统计学意义;Cox回归模型分析显示年龄≥40岁[HR=2.325,95%CI(1.398,3.866),P=0.000]、术前Harris评分70~80分[HR=2.163,95%CI(1.140,4.105),P=0.018]和<70分[HR=2.597,95%CI(1.173,5.749),P=0.019]、术前CJFH分型L2型[HR=35.052,95%CI(7.721,159.133),P=0.000)和L3型[HR=13.242,95%CI(3.104,56.491),P=0.000]是临床失败的危险因素。开窗减压组中不同年龄(χ2=8.437,P=0.004)、不同术前Harris评分(χ2=19.737,P=0.000)、不同术前CJFH分型(χ2=29.265,P=0.000)的临床失败率的差异有统计学意义;Cox回归模型分析显示术前Harris评分<70分[HR=5.102,95%CI(2.339,11.129),P=0.000]、术前CJFH分型L2型[HR=32.761,95%CI(6.165,43.507),P=0.000]是临床失败的危险因素。结论股骨头坏死保髋手术治疗效果受年龄、术前Harris评分和CJFH分型的影响;术前临床症状越明显,受累股骨头负重关节面及外侧柱支撑结构未得到有效重建,保髋手术的预后越差。     

基于CT坏死区重建的股骨头坏死侧位分型及其临床验证

目的 分析股骨头坏死（osteonecrosis of the femoral head,ONFH）不同日本厚生省骨坏死研究会（JIC）分型的股骨头塌陷与手术情况,总结各分型ONFH的预后规律,并对C1型探索基于CT坏死区重建的ONFH侧位分型的临床意义并验证其临床作用。方法 以2004年5月—2016年12月收治的119例（155髋）ONFH患者为研究对象,JIC分型：A型34髋,B型33髋,C1型57髋,C2型31髋。各JIC分型患者的年龄、性别、侧别、ONFH类型差异均无统计学意义（P>0.05）。分析不同JIC分型的1、2、5年股骨头塌陷及手术情况,以及不同JIC分型、激素性/非激素性ONFH、无症状与有症状（疼痛时间>6个月或≤6个月）髋关节间及联合保留角（combined preserved angle,CPA）≥118.725°和CPA<118.725°髋关节间的生存率（以股骨头塌陷为终点）。选取组内手术及塌陷发生差异较大、具备研究价值的JIC C1分型,根据其坏死区在股骨头表面的位置,在CT重建侧位将其分成5个亚型,并提取坏死区轮廓线,匹配至标准股骨头...     

关于中日友好医院(China-Japan Friendship Hospital，CJFH)股骨头坏死分型英文译文及缩写的修订说明

 我们撰写的“基于三柱结构的股骨头坏死分型——中日友好医院分型”一文在《中华骨科杂志》2012年第32卷第6期发表后倍受各方关注。读者认为基于股骨头三柱结构理论和影像学检查的中日友好医院(China-Japan Friendship Hospital，CJFH)股骨头坏死分型对预测股骨头塌陷将有重要意义。     

股骨头髓芯减压带旋髂深血管蒂髂骨骨瓣植骨治疗股骨头缺血性坏死

目的　探讨股骨头髓心减压带旋髂深血管蒂髂骨骨瓣植骨术治疗股骨头缺血坏死的疗效及手术适应证。　方法　 1995年 10月～ 2 0 0 0年 8月共进行 18例 (2 6髋 )股骨头髓心减压带旋髂深血管蒂髂骨骨瓣植骨术。根据Harris髋关节评分系统进行关节功能评价 ,根据ARCO分期分型系统进行影像学评价。　结果　随访 16例 2 3髋 ,平均 3 1 5个月。Harris评分由术前平均 61 7改善为随访时 76 0分。 13髋 (5 6% )随访时Harris评分 >80 0分 (内侧型 8髋 ,中央型 3髋 ,外侧型 2髋 ) ,根据ARCO分期分型系统进行分类随访时优良率 ,内侧型 80 % ,中央型 60 % ,外侧型 2 5 %。 8髋分期发生进展。塌陷及失败率内侧型 2 0 % ,中央型 40 % ,外侧型 75 %。　结论　股骨头髓芯减压带旋髂深血管蒂髂骨骨瓣植骨术适用于ARCO分期分型系统中ⅠA中央型、ⅠB内侧型、ⅡA中央型、ⅡB内侧型股骨头缺血性坏死 ,并具有良好的近、中期疗效。对坏死范围较大的股骨头不能防止病程的进展 ,但可缓解症状 ,延缓全髋关节置换的时间     

SARS后双侧股骨头坏死进展前瞻性分析

目的通过对SARS患者随访,了解应用激素后双侧股骨头坏死的发生发展状况,观察股骨头坏死的影象学变化。方法自2003年7月～2008年7月对北京市的使用激素治疗的539例SARS患者进行了随访,全部患者在开始使用激素后2～6个月行双髋MRI检查、X线摄片以及体格检查等,检出后定期行坏死关节的X线摄片及CT扫描,如出现关节疼痛等则及时摄片观察。股骨头坏死按照ARCO国际骨循环协会分期,III期作为观察终点。结果 539例应用激素者检出骨坏死176例(32.7%),其中累及股骨头为130例,双侧股骨头骨坏死86例;病例占股骨头坏死的66.2%。73例得到连续随访。目前进入III期为6～46个月,73例146髋中塌陷27髋,23髋为IIC期进展,4髋为IIB期进展;双侧塌陷4例。负重面外侧型(49髋)塌陷23髋,负重面中央型(61髋)塌陷4髋,负重面内侧型(36髋)无塌陷。早期MRIT1中低信号带的形态:开放型-开放型27例,塌陷12例16髋;开放型-包含型25例,开放型塌陷9例9髋,包含型塌陷2例2髋;包含型-包含型21例,无塌陷髋。开放型塌陷比例为25/79;包含型塌陷比例为2/67。结论坏死灶的大小位置影响双侧股骨头坏死的预后;坏死灶上负重面外侧型更易早塌陷;对于双侧股骨头坏死的病例,MRI显示相似的面积,T1低信号带包含型者,预后相对较好;CT显示软骨下骨均匀增厚或明显的"焊接"现象是延迟塌陷的因素;但是软骨下骨没有或有不均匀(不连续)硬化是危险因素。     

儿童及青少年股骨颈骨折后股骨头坏死影像学特征与疾病进展的关系

目的分析儿童及青少年股骨颈骨折后股骨头坏死的影像学特点及其与疾病进展的关系。方法收集广州中医药大学第一附属医院治疗的58例儿童及青少年股骨颈骨折后股骨头坏死患者影像学资料。研究对象的入选标准包括:年龄小于18岁的儿童及青少年;明确股骨颈骨折病史;符合股骨头坏死诊断标准。排除标准包括:大剂量激素使用史或酗酒史;诊断Legg-Calve-Perthes病、戈谢氏病、镰状细胞性贫血症、先天性髋关节发育不良、类风湿性关节炎、强直性脊柱炎、股骨颈骨折骨不连、术后感染;已接受针对股骨头坏死治疗,或影像资料不完整的患者。其中男性38例,女性20例,平均年龄(14.7±2.9)岁,均为单侧坏死(左侧31例,右侧27例)。通过Steinberg分期评估疾病进展,Spearman相关性检验或Fisher精确检验分析坏死面积、日本厚生省骨坏死研究会(JIC)分型以及蛙位分型等影像学特点与疾病进展的关系。结果初次就诊时,根据Steinberg分期,Ⅰ期3例(5.2%),Ⅱ期21例(36.2%),Ⅲ期5例(8.6%),Ⅳ期25例(43.1%),Ⅴ期4例(6.9%)。Steinberg分期与坏死面积(r=0.5,P0.01)、JIC分型(r=0.5,P0.01)以及蛙位分型(r=0.5,P0.01)呈正相关。在已塌陷的29例患者中,19例出现髋关节失稳,表现为严重塌陷后头臼不匹配、关节半脱位。蛙位C2型失稳率为90.0%(18/20),蛙位C1型为11.1%(1/9),其差异具有统计学意义(P0.01);正位C2型失稳率为68.0%(17/25),正位C1型为50%(2/4),其差异无统计学意义(P0.05)。结论儿童及青少年股骨颈骨折后股骨头坏死塌陷风险极高,严重塌陷可导致髋关节失稳,尤其多见于蛙位C2型坏死。     

双锁定钢板交叉支撑固定治疗累及后外侧的C3型胫骨平台骨折

 目的 探讨应用前外侧结合前内侧入路、双锁定钢板交叉支撑固定治疗伴有后外侧劈裂塌陷的 C3 型胫骨平台骨折的可行性、手术方法及近期疗效。方法 回顾性分析 2011 年 3月至 2012年 12月,采用前外侧结合前内侧入路、双锁定钢板交叉支撑固定治疗 15例累及后外侧的 C3型胫骨平台骨折的患者资料,男 9例,女 6例;年龄 27~56岁,平均 42.6岁;均为闭合性骨折。术后进行临床及影像学检查,对术后 X线片采用 Rasmussen放射学评分进行评估,在术后第 12个月随访时采用美国特种外科医院（hospital for special surgery, HSS）评分对膝关节功能进行评估。结果 15例患者均获得随访,随访时间 12~23个月,平均 13.5个月;手术时间 120~210 min,平均 196 min。术后完全负重时间 8~20周,平均 11.6周;骨折临床愈合时间 12~16周,平均 13.8周。术后即刻、3个月、6个月、12个月在 X线片上测量的患肢胫骨平台内翻角及后倾角度数比较,差异均无统计学意义。膝关节功能 HSS评分为 85~95分,平均 89.5分,均为优;术后 Rasmussen放射学评分为 14~18分,平均 16.2分。1例患者术后 2周出现内侧切口约 4 cm的皮肤坏死,经清创负压引流后愈合。末次随访无一例发生感染、骨折不愈合、复位高度丢失、内固定松动、膝关节不稳及医原性神经、血管损伤等并发症。结论 采用前外侧结合前内侧入路、双锁定钢板交叉支撑固定治疗伴有后外侧劈裂塌陷的 C3型胫骨平台骨折方法可行,该方法术中暴露充分,能够允许膝关节进行早期功能锻炼;术后近期疗效满意,未见明显角度丢失及关节面的再次塌陷,膝关节功能恢复好,未出现血管神经损伤、感染等严重并发症。     

The Effect of the Hip Flexion Angle in Osteonecrosis of the Femoral Head Based on China‐Japan Friendship Hospital Classification ‐ A Finite Element Study

Objective

The alteration in the mechanical environment of the necrotic area is the primary cause of the collapse observed in osteonecrosis of the femoral head (ONFH). This study aims to evaluate the biomechanical implications of the China-Japan Friendship Hospital (CJFH) classification system and hip flexion angles on the necrotic area in ONFH using finite element analysis (FEA). The goal is to provide valuable guidance for hip preservation treatments and serve as a reference for clinical diagnosis and therapeutic interventions.

Methods

Hip tomography CT scan data from a healthy volunteer was used to create a 3D model of the left hip. The model was preprocessed and imported into Solidworks 2018, based on the CJFH classification. Material parameters and boundary conditions were applied to each fractal model in ANSYS 21.0. Von Mises stresses were calculated, and maximum deformation values were obtained to evaluate the biomechanical effects of the load on the necrotic area and post-necrotic femur, as well as assess each fractal model's collapse risk.

Results

(1) At the same hip flexion angle, maximum deformation followed this order: M Type < C Type < L Type. The L3 type necrotic area experienced the most significant deformation at 0, 60, and 110° angles (1.121, 1.7913, and 1.8239 mm respectively). (2) Under the same CJFH classification, maximum deformation values increased with hip flexion angle (0 < 60 < 110°), suggesting a higher risk of collapse at larger angles. (3) Von Mises stress results showed that the maximum stress was not located in the necrotic area but near the inner and outer edge of the femoral neck, indicating decreased stiffness and strength of the subchondral bone after osteonecrosis.

Conclusion

The study found that femoral head collapse risk was higher when the necrotic area was located in the lateral column under the same stress load and flexion angle. Mechanical properties of the necrotic area changed, resulting in decreased bone strength and stiffness. Large-angle hip flexion is more likely to cause excessive deformation of the necrotic area; thus, ONFH patients should reduce or avoid large-angle hip flexion during weight-bearing training in rehabilitation activities.     

加入和未加骨形态发生蛋白2的打压植骨术治疗股骨头坏死

背景：已知骨形态发生蛋白2（bone morphogenetic protein2,BMP2）能促进骨愈合,但能否加速股骨头坏死打压植骨术的修复尚不知。目的：回顾性对照分析加入和未加入BMP2的打压植骨术治疗股骨头坏死（osteonecrosis of the femoral head,ONFH）的疗效。方法：42例（72髋）非创伤性ONFH手术患者获得随访,男19例,女23例;手术时年龄22~54岁,平均30.9岁。手术方法为经髋关节前路,股骨头颈交界处开窗,坏死灶清除,人工骨打压植骨。第一组每例加入4mgrhBMP2,第二组未加。患髋按国际骨循环学会（Association Research Circulation Osseous,ARCO）分期,按中日友好医院（China-Japan Friend-ship Hospital,CJFH）分型。临床疗效按Harris髋关节功能评分（Harris hip score,HHS）评定,影像学按股骨头是否塌陷及病灶修复情况评定。结果：随访5~7.8年（平均6.1年）。优36髋,良12髋,尚可7髋。股骨头保存率76.4%,第一组为81.8%,第二组为71.8%（P=0.459）。ARCOⅡ期为90.3%,Ⅲa期为34.6%（P=0.0285）;CJFH-C型及L1型为95.3%,L3型为29.6%（P=0.050）。结论：经股骨头颈开窗病灶清除,打压植骨术在选择合适的非创伤ONFH患者（ARCOⅡb,c期及CJFHC型和L1型）可获得优良的中期疗效。加入rhBMP2可提高手术疗效和骨修复质量。     

The 2021 Association Research Circulation Osseous Classification for Early-Stage Osteonecrosis of the Femoral Head to Computed Tomography–Based Study

BackgroundThe Association Research Circulation Osseous developed a novel classification for early-stage (precollapse) osteonecrosis of the femoral head (ONFH). We hypothesized that the novel classification is more reliable and valid when compared to previous 3 classifications: Steinberg, modified Kerboul, and Japanese Investigation Committee classifications.MethodsIn the novel classification, necrotic lesions were classified into 3 types: type 1 is a small lesion, where the lateral necrotic margin is medial to the femoral head apex; type 2 is a medium-sized lesion, with the lateral necrotic margin being between the femoral head apex and the lateral acetabular edge; and type 3 is a large lesion, which extends outside the lateral acetabular edge. In a derivation cohort of 40 early-stage osteonecrotic hips based on computed tomography imaging, reliabilities were evaluated using kappa coefficients, and validities to predict future femoral head collapse by chi-squared tests and receiver operating characteristic curve analyses. The predictability for future collapse was also evaluated in a validation cohort of 104 early-stage ONFH.ResultsIn the derivation cohort, interobserver reliability (k = 0.545) and intraobserver agreement (63%-100%) of the novel method were higher than the other 3 classifications. The novel classification system was best able to predict future collapse (P < .05) and had the best discrimination between non-progressors and progressors in both the derivation cohort (area under the curve = 0.692 [0.522-0.863], P < .05) and the validation cohort (area under the curve = 0.742 [0.644-0.841], P = 2.46 × 10^?5).ConclusionThis novel classification is a highly reliable and valid method of those examined. Association Research Circulation Osseous recommends using this method as a unified classification for early-stage ONFH.Level of EvidenceLevel III, diagnostic study.     

The 2001 revised criteria for diagnosis, classification, and staging of idiopathic osteonecrosis of the femoral head

 The 2001 revised criteria for the diagnosis, classification, and staging of idiopathic osteonecrosis of the femoral head were proposed in June 2001, by the working group of the Specific Disease Investigation Committee under the auspices of the Japanese Ministry of Health, Labor and Welfare, to establish criteria for diagnosis and management of idiopathic osteonecrosis of the femoral head. Five criteria that showed high specificity were selected for diagnosis: collapse of the femoral head (including crescent sign) without joint-space narrowing or acetabular abnormality on x-ray images; demarcating sclerosis in the femoral head without joint-space narrowing or acetabular abnormality; “cold in hot” on bone scans; low-intensity band on T1-weighted MRI (bandlike pattern); and trabecular and marrow necrosis on histology. Idiopathic osteonecrosis of the femoral head is diagnosed if the patient fulfills two of these five criteria and does not have bone tumors or dysplasias. Necrotic lesions are classified into four types, based on their location on T1-weighted images or x-ray images. Type A lesions occupy the medial one-third or less of the weight-bearing portion. Type B lesions occupy the medial two-thirds or less of the weight-bearing portion. Type C1 lesions occupy more than the medial two-thirds of the weight-bearing portion but do not extend laterally to the acetabular edge. Type C2 lesions occupy more than the medial two-thirds of the weight-bearing portion and extend laterally to the acetabular edge. Staging is based on anteroposterior and lateral views of the femoral head on x-ray images. Stage 1 is defined as the period when there are no specific findings of osteonecrosis on x-ray images, although specific findings are observed on MRI, bone scintigram, or histology. Stage 2 is the period when demarcating sclerosis is observed without collapse of the femoral head. Stage 3 is the period when collapse of the femoral head, including crescent sign, is observed without joint-space narrowing. Mild osteophyte formation in the femoral head or acetabulum may be observed in stage 3. Stage 3 is divided into two substages. In stage 3A, collapse of the femoral head is less than 3 mm. In stage 3B, collapse of the femoral head is 3 mm or greater. Stage 4 is the period when osteoarthritic changes are observed. Received: April 18, 2002 / Accepted: April 21, 2002     

Is bone mineral density lower in the necrotic lesion in pre-collapse osteonecrosis of the femoral head?

The purpose of this study was to clarify whether bone mineral density (BMD) of the necrotic lesion in precollapse osteonecrosis of the femoral head (ONFH) is reduced according to Hounsfield unit (HU) values on computed tomography (CT). The superior one-third of the femoral head in the coronal section was set as the region of interest (ROI) for the measurement of HU values. First, HU values of 101 control participants were assessed to identify relevant confounding factors. Next, the relationship between HU values and BMD on dual-energy X-ray absorptiometry (DXA) was verified. Then the mean HU value of the ROI in patients with pre-collapse ONFH was compared with that in propensity score-matched control participants. Finally, the HU values of the lateral boundary in the patients with and without subsequent collapse were compared. Multivariable analysis showed that both age and BMI were significantly correlated with the HU value, which showed a strong correlation with the BMD of the femoral neck on DXA (r = 0.92). In 25 ONFH patients and 25 propensity-matched control participants, no significant difference was found in the HU value of the ROI (p = .54). The mean HU value of the lateral boundary in patients with subsequent collapse was found to be significantly higher than that in patients without subsequent collapse (p < .01). The assessment of HU values on CT was useful for the evaluation of BMD of the femoral head. The current assessment did not demonstrate reduced bone mineral density of the necrotic lesion in pre-collapse ONFH     

Collapse Progression or Cessation Affects the Natural History of Contralateral Osteonecrosis of the Femoral Head

BackgroundIt is unclear how the condition of one side of the hip joint affects the natural history of contralateral osteonecrosis of the femoral head (ONFH). This study aimed to investigate the natural progression of bilateral ONFH on the asymptomatic side between patients with collapse progression and cessation on the symptomatic side.MethodsThe study included 109 patients with bilateral ONFH at the first visit, who were divided into two groups in accordance with the symptomatic side based on the collapse progression of ≥3 mm (progressive group: 74 hips) and collapse cessation of <3 mm (stable group: 35 hips) with a minimum follow-up of 3 years. The assessment parameters included age, gender, body mass index, etiology, type classification, and survival rates of the asymptomatic side with radiographic failure as the endpoints.ResultsAge, gender, body mass index, and etiology were not different between the two groups; however, a difference was observed in the type classification of the symptomatic side. The 4-year survival rates were significantly different between the progressive (34.3%) and stable groups (85.7%). Multivariate Cox regression analysis showed that age <40 years (vs ≥40 years; hazard ratio [HR], 2.439), type C2 (vs B + C1; HR, 2.865), and collapse progression on the symptomatic side (vs collapse cessation; HR, 7.751) were independent factors determining collapse on the asymptomatic side.ConclusionCollapse progression on the symptomatic side is a poor prognostic factor for the natural history of contralateral ONFH.