髋关节发育不良的髋臼重建

目的　总结采用全髋关节置换术治疗髋关节发育不良继发骨关节炎和功能障碍的经验。方法　 1998年 4月至 2 0 0 2年 4月 ,对 96例 112髋 (双侧 16例 )成人髋关节发育不良继发骨关节炎患者进行了全髋关节置换术。其中 ,半脱位 73髋 ,低位脱位 18髋 ,高位脱位 2 1髋。髋臼侧均采用真臼位置重建 ,其中骨水泥固定 16髋 ,非骨水泥固定 96髋 ,植骨 11髋 ;采用常规置换 83髋 ;磨削加深髋臼后 ,安置小号髋臼假体 2 7髋 ;髋臼外上缘自体股骨头植骨加深髋臼后 ,安置小号髋臼假体 2髋。结果　患者术后伤口均一期愈合 ,未发生感染或血管神经损伤 ,患肢长度平均延长 1 7cm。随访 85例 98髋 ,平均随访 3 5年 ,关节疼痛缓解 ,活动功能满意 ,Harris评分由术前的平均 33 9分恢复到平均 89 3分 ,无假体松动和翻修病例。X线片显示 ,关节假体位置正常 ,人工髋臼的平均外展角4 4° ,宿主骨对臼杯的平均覆盖率为 96 6 % ,金属臼杯与宿主髋臼之间未见透光线 ;11髋髋臼侧植骨病例中 ,植骨块与宿主骨愈合良好 ,未见骨吸收现象。结论　全髋关节置换术是治疗髋关节发育不良继发骨关节炎患者的有效方法 ;术前应充分考虑髋关节发育不良的原发及继发性病理改变 ,尽可能在真臼位置重建髋臼     

先天性髋关节发育不良伴继发性骨性关节炎的病理特点及全髋关节置换术近期疗效观察

[目的]探讨非骨水泥假体的全髋置换术治疗成人先天性髋臼发育不良伴继发性骨关节炎的经验及评价全髋置换术后的近期疗效.[方法]自2000年3月至2007年3月,对25例30髋成人先天性髋臼发育不良伴继发性骨关节炎的患者进行了非骨水泥假体的全髋置换术,其中男5例,女20例;年龄35～55岁,平均45岁,双侧5例,单侧20例.主要症状为疼痛及跛行.根据Hartofilakidis分类方法,半脱位21髋,高位脱位9髋.[结果]经8个月～7年平均3年9个月的随访.Harris评分由术前36.09恢复到术后的88.21.所有病人患髋疼痛基本消失,可以长时间行走,X线片示人工髋关节位置良好,假体无松动及明显下沉迹象,生活自理并恢复日常工作.[结论]非骨水泥假体全髋关节置换术是治疗成人先天性髋臼发育不良伴继发性骨关节炎的有效方法.选择合适的假体,髋臼的加深及恰当的髋臼缺损处骨移植是手术成功的关键.     

髋臼重建及股骨转子下短缩截骨全髋关节置换治疗Crowe Ⅳ型髋关节发育不良

 目的 探讨髋臼重建及股骨转子下短缩截骨全髋关节置换治疗Crowe Ⅳ型髋关节发育不良的临床疗效。方法 2003年9月至2012年9月收治Crowe Ⅳ型髋关节发育不良患者21例(24髋),男3例,女18例;年龄28~71岁,平均(54±10)岁。采用髋臼重建,股骨转子下横行短缩截骨,股骨近端非骨水泥假体全髋关节置换术。髋臼成形后联合自体结构性骨移植修复骨缺损,生物型假体或钛网骨水泥重建髋臼。陶瓷-聚乙烯股骨头臼界面17例(20髋),金属-聚乙烯4例(4髋)。股骨截骨端自体骨移植18例(21髋),异体骨移植原位钢丝捆扎3例(3髋)。术后采用Harris髋关节评分系统评估髋关节功能。结果 3例失访。随访18例(21髋),随访时间0.5~9年,平均3.5年。Harris髋关节评分从术前(47.9±9.1)分提高至术后6个月(88.4±3.5)分。术后髋关节疼痛明显改善,肢体活动度增加,步态接近正常。1例术后并发坐骨神经麻痹,无伤口感染病例。术后6个月X线片均显示髋臼假体骨性覆盖、假体及植骨床压配较好,无髋臼假体松动及植骨块明显吸收,截骨端骨愈合良好。结论 髋臼重建及股骨转子下短缩截骨全髋关节置换适用于Crowe Ⅳ型髋关节发育不良,尤其是高龄髋关节高脱位患者。操作相对简单,能够改善肢体不等长,可避免一次性过度肢体延长导致的坐骨神经损伤。     

非短缩截骨全髋关节置换术治疗严重髋关节发育不良

目的 观察非短缩截骨全髋关节置换术治疗髋关节发育不良继发骨关节炎的临床疗效.方法 2004年12月至2008年12月收治20例(21髋)CroweⅢ或Ⅳ型髋关节发育不良继发髋关节骨关节炎患者,男1例,女19例;年龄19～44岁,平均32.1岁.术前Harris评分(44.3±16.7)分.肢体短缩3.0～6.5 cm,平均4.6 cm.采用后外侧入路,行非股骨短缩截骨的全髋关节置换术,其中14例15髋用自体股骨头植骨重建髋臼.术后早期采取屈髋屈膝位松弛坐骨神经和股神经,仅行下肢肌肉静力性收缩训练,逐渐减少屈髋及屈膝角度至伸髋、伸膝正常.髋臼重建患者术后6周避免负重.结果 所有患者随访8～48个月,平均25.3个月.患肢延长2.9～5.3 cm,平均(3.9±0.7)cm;较对侧短缩0～1.6 cm,平均(0.5±0.3)cm.术后下肢肌肉主动静力性收缩均正常,2例出现小腿皮肤麻木感,1个月后恢复.X线片显示假体位置均满意,髋臼重建患者髋臼假体完全骨性覆盖,植骨块与假体及植骨床压配紧密,无髋臼假体松动及植骨块不愈合、吸收.2例出现异位骨化.末次随访Harris评分(86.3±10.7)分,与术前比较差异有统计学意义.结论 非短缩截骨及自体股骨头结构性植骨全髋关节置换术能重建复杂髋关节发育不良的生物学及生物力学,不增加并发症风险.术后早期软组织平衡应逐渐恢复,强调个体化康复方案.     

结构性植骨全髋关节置换在成人高位先天性髋关节脱位中的应用

[目的]探讨结构性植骨全髋关节置换治疗成人高位先天性髋关节脱位的临床疗效。[方法]2003年8月～2006年10月,采用结构性植骨全髋置换治疗成人高位先髋脱位22例,29髋。男10例,女12例。左13例,右16例,年龄平均34.6岁(23～42岁)。临床症状主要为患髋疼痛、不稳定和跛行。术前Harris评分平均为46.8分,双下肢长度差异平均为3.8cm,股骨头脱位高度平均为3.9cm,髋关节平均活动度:屈曲66.5°,外展23.8°,外旋20.4°,内旋5.3°。术中臼杯均安装于真臼处,自体股骨头结构性植骨使臼杯完全覆盖,充分软组织松解后髋关节复位。髋臼侧选用骨水泥假体18髋、小髋臼生物型假体5髋和普通生物型髋臼6髋;股骨侧选用生物型假体10髋、普通骨水泥假体13髋、窄直柄水泥假体柄4髋和长柄骨水泥假体柄2髋。观察手术时间、出血量、关节活动度、双下肢长度差异、并发症等并进行Harris关节功能评分。[结果]本组平均手术时间95min(70～135min),出血400ml(300～650ml);伤口均一期愈合,无1例感染;术后1周X线片示假体位置良好,人工髋臼外展角平均为48.6°,前倾角平均13.2°。本组22例均获随访,随访时间平均17.6个月(10～47个月),Harris评分平均89.2分(72～93分);髋关节平均活动度:屈曲115.3°,外展44.6°,外旋49.5°,内旋26.8°。双下肢长度差异平均1.2cm,2例术后股神经麻痹,术后4个月内恢复。随访期间未见明显植骨块吸收、假体松动和脱位。[结论]结构性植骨全髋关节置换是治疗成人高位先天性髋关节脱位的一种有效方法,很大程度地改善了患者的症状、功能和外形。结构性植骨可提供良好的髋臼覆盖,恢复髋关节旋转中心高度并可保留骨盆骨量。脱位高度小于4cm经软组织充分松解后能下拉复位,不会造成股神经及坐骨神经永久性麻痹。     

全髋置换治疗先天性髋臼发育不良临床疗效观察

[目的]了解全髋置换治疗先天性髋臼发育不良术后的中远期疗效。[方法]采用人工全髋关节假体，对23例25个先天性髋臼发育不良继发髋关节骨关节炎患者行全髋关节置换（THR），Pemer分型Ⅰ度15例，17个髋；Ⅱ度5例，5个髋；Ⅲ度2例，2个髋；Ⅳ度1例，1个髋。固定方法：髋臼侧，5髋为骨水泥固定，20髋为非骨水泥固定；股骨侧，7髋为骨水泥固定，18髋为非骨水泥固定。[结果]1例术中发生小转子劈裂，1例术后发生下肢静脉炎，3例两侧肢体不等长2am以上。随访3—11年，平均8．2年，术前Harris评分最高59分，最低25分，平均44．5分。所有患者术后髋关节疼痛消失，关节活动度增加，Harris评分最高97分，最低63分，平均85．6分。[结论]先天性髋关节脱位的全髋关节置换术，手术相对比较复杂并发症较多，手术中特别需要考虑两侧肢体的长度、外展肌的平衡、软组织的松解、髋臼骨缺损的处理及假体的选择。     

软组织平衡在全髋关节置换术治疗成人高位髋关节发育不良中的应用

目的 评价软组织平衡技术在全髋关节置换术治疗成人高位髋关节发育不良的效果.方法 2000年12月至2006年8月应用全髋关节置换术治疗21例(26髋)高位髋关节发育不良患者(CreweⅢ型20髋;Ⅳ型6髋).通过软组织松解及股骨转子下短缩截骨重建髋臼于真臼水平,评价其术后临床及影像学结果.术前Harris评分平均41.2分.结果 21例患者获得13个月～7年随访,平均随访时间4.8年.16例患者术后跛行程度明显改善;通过软组织松解可显著纠正下肢不等长,有效减少手术截骨长度.术后Harris评分平均89.6分.患者术后未见脱位、感染及假体松动.结论 适当的软组织松解和平衡可使高位髋臼重建于真臼,有效地恢复髋关节的形态和功能,获得满意的近期效果.     

S-ROM假体全髋关节置换治疗Crowe Ⅳ型髋关节发育不良

目的:探讨S-ROM假体全髋关节置换术治疗CroweⅣ型髋关节发育不良的方法并评价其疗效。方法:2000年10月至2011年10月,应用全髋关节置换术治疗CroweⅣ型髋关节发育不良患者30例36髋,其中6例双侧,24例单侧。采用S-ROM假体结合股骨转子下横断截骨短缩行人工关节置换术,髋臼侧均采用生物型假体,假体在真臼水平或接近于真臼水平植入。对临床结果采用改良Harris评分进行评价,术前及术后随访时均拍X线片进行观察。结果:30例中早期死亡l例(双髋),失访2例(2髋),余27例32髋获得随访,时间7～84个月,平均48个月。2髋分别于术后12、18个月随访时仍可见骨折线,下肢行走无异常,术后未发生感染或神经损伤等严重并发症。改良Harris评分由术前平均41.7±3.7改善至术后89.1±2.9。无假体松动或位置不当需要翻修的病例。影像学复查显示关节假体在位,金属臼杯、股骨假体与宿主骨嵌合良好,无明显松动。所有施行臼侧植骨及股骨截骨的患者植骨及截骨处均骨性愈合,无假体松动,活动度无明显受限,患髋无痛,Trendelenburg征阴性,均无须使用行走辅助工具。结论:对CroweⅣ型髋关节发育不良患者行全髋关节置换术时,良好的真臼暴露、加深髋臼、股骨短缩、斜行截骨及使用S-ROM组配式股骨柄假体假体能提高全髋关节置换术的治疗效果。     

人工全髋置换术治疗先天性髋关节发育不良

目的探索全髋关节置换术治疗先天性髋关节发育不良的经验及疗效。方法13例（15髋）先天性髋关节发育不良继发骨性关节炎行全髋关节置换术。随访11例12髋，平均随访时间2.6a，按Crowe分类，其中Ⅰ型6例7髋，Ⅱ型3例髋，Ⅲ型2例2髋，Ⅳ型2例3髋。其中髋臼侧用骨水泥型假体5例，非骨水泥型10例，股骨侧骨水泥型4例，非骨水泥型11例。结果 1例髋小转子劈裂骨折，1例术后深静脉栓塞，随访期未见有感染，异位骨化，假体松动，坐骨神经损伤等并发症。术前Harris评分平均47例，术后2.6a为88分。结论 全髋关节置换术是治疗成份先天性髋关节脱位继发骨性关节炎的有效方法，但手术难度较大，手术中应特别考虑外展肌的平衡，软组织的松解，髋臼骨缺损的处理以及双侧肢体的长度。     

全髋关节置换术治疗成人Crowe Ⅳ型先天性髋关节脱位的临床研究

目的探讨CroweⅣ型先天性髋关节脱位患者全髋关节置换术的手术方法及预防神经损伤的对策。方法35例（39髋）CroweⅣ型先天性髋关节脱位患者行全髋关节置换术,均为女性,年龄36～56岁,平均46岁。获得随访31例35髋,随访时间1年～8年,平均4年。手术采用后外侧切口。髋臼侧除1例2髋外,均在真臼水平安放臼杯并使用非骨水泥型假体,股骨侧5例5髋选用骨水泥型假体,其余均选用非骨水泥型假体。2例2髋以往曾行转子下截骨者先行转子下截骨矫正术,再植入非骨水泥型假体。采用髋关节功能评分（Harris评分）评定髋关节功能,术前平均43分。结果获得随访的31例（35髋）中,5例5髋发生术中骨折,其中小转子轻微襞裂骨折3例3髋,大转子不全骨折2例2髋,但股骨假体稳定,予钢丝固定或未作特殊处理。3髋发生异位骨化,均为BrookⅡ型。2例术后分别出现坐骨神经或股神经刺激症状,1个月后恢复正常。随访期间内无一例发生术后感染、术中术后髋关节脱位、假体松动及有明显临床表现的深静脉血栓形成等并发症。术后随访时Harris评分平均87分,术后肢体延长4～6cm,平均5cm,肢体短缩得到满意纠正。结论后外侧人路、真臼水平重建髋臼是CroweⅣ型先天性髋关节脱位全髋关节置换术安全、有效的手术方法。     

全髋关节置换术治疗髋关节发育不良的临床疗效分析

目的分析先天性髋关节发育不良（developmental dysplasia of the hip,DDH）行全髋置换的治疗效果,探讨其手术方法和假体的选择。方法回顾分析2004年6月至2007年6月收治的65例（78髋）成人先天性髋关节发育不良患者,男19例,女46例;年龄33～64岁,平均42岁。按Crowe分型标准,Ⅰ型12例,Ⅱ型26例,Ⅲ型24例,Ⅳ型16例;术前Harris评分35～78分（平均42.7分）,Ⅰ～Ⅱ型患者行常规全髋置换,Ⅲ型患者髋臼骨质缺损部植骨后行全髋置换,Ⅳ型患者股骨短缩截骨后使用特殊假体。结果65例患者均获得随访,随访时间2.5～5.5年,术后Harris评分68～94分（平均84分）,除2例CroweⅣ型患者术后患肢大腿内侧出现麻木（给予功能锻炼、药物治疗后,分别于术后半年、1年后症状消失）,其余患者无骨折、感染、深静脉血栓形成或假体松动、脱位等并发症,CroweⅣ患者截骨处骨愈合均良好。结论全髋关节置换术是治疗成人先天性髋关节发育不良继发骨性关节炎、脱位的有效方法,但手术难度大,应针对髋臼病变程度的不同及术前情况制定合适的方案,采用不同的关节假体,配合术中的正确操作,才能提高疗效,减少并发症。     

Epidemiology, demographics, and natural history of congenital hip disease in adults

This study examined the epidemiology and demographics of congenital hip disease in 468 (660 hips) patients who were examined between 1970 and 1996. In 356 (54%) hips, the diagnosis was secondary osteoarthritis due to congenital hip disease, and in 272 (41%) hips, the diagnosis was idiopathic osteoarthritis. In the remaining 32 (5%) hips, the diagnosis was uncertain. Of the hips with congenital hip disease, 170 (47.7%) hips were dysplastic, 85 (23.9%) had low dislocation, and 101 (28.4%) high dislocation. The majority of patients with congenital hip disease were women (338 [95%] hips). The natural history of the three types of congenital hip disease was studied in 157 patients (202 hips: 102 dysplastic, 42 low dislocation, and 58 high dislocation) who had received no treatment before the initial examination. Average length of follow-up was 17 years. In dysplastic hips, the disease remained undiagnosed until the onset of symptoms at an average age of 34.5 years. In patients with low dislocation, pain had started at an average of 32.5 years due to progressive degenerative arthritis within the false acetabulum. In patients with high dislocation, in the presence of a false acetabulum, pain started at an average age of 31.2 years, while in its absence, pain started at an average age of 46.4 years due to muscle fatigue. These findings suggest dysplasia, low dislocation, and high dislocation in adults are the results of untreated dysplasia, subluxation, and complete dislocation in infancy, respectively.     

全髋关节置换术治疗成人先天性髋关节脱位

目的探讨全髋关节置换术治疗成人先天性髋关节脱位继发假臼骨关节炎的经验。方法1998年4月～2000年4月,对9例14髋成人先天性髋关节脱位继发假臼骨关节炎患者,进行了全髋关节置换术。其中双侧5例,单侧4例。结果术后伤口均一期愈合,经6个月～2年的随访,平均Harris评分由术前的33.93分恢复到术后6个月的89.21分。患者均能自行下地行走,生活自理且恢复日常工作。结论全髋关节置换术是治疗成人先天性髋关节脱位继发假臼骨关节炎的有效方法,但手术难度较大。手术中应充分考虑先天性髋关节脱位的原发及继发性病理改变,以采取相应的措施。     

Midterm Results of Hybrid Total Hip Arthroplasty for Treatment of Osteoarthritis Secondary to Developmental Dysplasia of the Hip-Chinese Experience

This study was designed to evaluate the midterm results of hybrid total hip arthroplasty in a consecutive series of 45 Chinese patients with osteoarthritis secondary to dysplastic hip. The average follow-up was 6.6 years. A total of 24 hips were classified as dysplasia, 20 hips as low dislocation, and 13 hips as high dislocation. The preoperative Harris score was 46.19 ± 18.01, which improved to 91.78 ± 3.52 at the final follow-up. The rate of polyethylene liner wear was 0.27 mm/y. Osteolysis was identified around 5 acetabular components and 13 femoral components. With the use of loosening or revision as the end point for failure, the survival rate was 1.0. We suggest that hybrid total hip arthroplasty in Chinese developmental dysplasia of hip patients has favorable results at midterm follow-up, even though their lifestyle includes more deep flexion of the hip. There is no significant difference of postoperative Harris score with increasing severity of dysplasia.     

Primary total hip arthroplasty in severe developmental dysplasia of the hip. Ten-year results using a cementless modular stem

We report the average 10-year clinical and radiographic results of 28 hips with Crowe III or IV developmental dysplasia of the hip (DDH) and a technically difficult primary hip arthroplasty using the cementless modular S-ROM stem (DePuy Orthopedics, Warsaw, Ind). Twenty-one patients required significant autologous bone grafting, 1 had a large allograft, and 6 patients required femoral shortening at the time of their total hip arthroplasty. Three patients had an intraoperative technical complication. The average preoperative Harris hip score was 37; at 10 years, 81. The Short Form 12 was 41.64 physical/54.03 mental at 10 years, and the WOMAC average score was 23 at 10 years. None of the S-ROM stems had been revised or were loose at latest follow-up. Six hips had osteolysis in Gruen zones 1 or 7 but none around or distal to the sleeve. The 10-year results of the S-ROM stem used in patients with osteoarthritis secondary to severe DDH are excellent.     

螺旋臼全髋关节置换术治疗发育性髋关节发育不良

目的探讨使用螺旋臼假体治疗发育性髋关节发育不良（DDH）继发骨性关节炎患者的临床疗效。方法自2003年5月至2007年12月，使用Zweymaller螺旋臼假体治疗40例（43髋）DDH继发骨性关节炎患者，其中男6例（6髋），女34例（37髋），平均年龄47．6岁（22～70岁）；单侧37例，双侧3例；Crowe分型：Ⅰ级6例，Ⅱ级24例，Ⅲ级10例，Ⅳ级3例。平均随访24．6个月，术前Harris评分最高61分，最低22分，平均43．5分。结果所有患者术后疼痛基本消失，双下肢长度差异平均1．2cm，2例术后出现股神经损伤症状，术后6个月症状基本消失，Harris评分最高97分，最低62分，平均85．3分。结论使用Zweymtiller螺旋臼假体治疗DDH继发骨性关节炎的患者，可以达到良好的恢复关节功能的临床疗效，手术不需大块植骨和骨水泥，初期临床效果满意。     

Total hip arthroplasty for congenital hip disease

BACKGROUND: It is generally agreed that the clinical and radiographic results of total hip replacement performed for degenerative arthritis secondary to congenital hip disease vary depending on the severity of the anatomical abnormality. In this study, we report the mid-term and long-term clinical and radiographic results of total hip arthroplasty performed for each of the three different types of congenital hip disease. METHODS: Between 1976 and 1994, the senior author performed 229 consecutive primary total hip arthroplasties in 168 patients with osteoarthritis secondary to congenital hip disease. Seventy-six hips were dysplastic, sixty-nine had a low dislocation, and eighty-four had a high dislocation. The Charnley low-friction technique was performed in 178 hips, and the so-called hybrid technique was performed in forty-six hips. Cementless arthroplasty was used in only five hips. RESULTS: After a minimum of seven years of follow-up, the rates of revision of the acetabular components were 15% in the dysplastic hips, 21% in the hips with a low dislocation, and 14% in those with a high dislocation. The rates of revision of the femoral components were 14%, 14%, and 16%, respectively. Survivorship analysis predicted an overall rate of prosthetic survival at fifteen years of 88.8% +/- 4.8% in the dysplastic hips, 73.9% +/- 7.2% in the hips with a low dislocation, and 76.4% +/- 8.1% in those with a high dislocation. CONCLUSIONS: An understanding of the anatomical abnormalities and the use of appropriate techniques and implants make total hip arthroplasty feasible for treatment of the three types of congenital hip disease. In patients with a low dislocation, the major technical problem is reconstruction of the natural acetabulum. In those with a high dislocation, the challenge is to place the acetabular component inside the reconstructed true acetabulum and to use an appropriate femoral implant in the hypoplastic narrow femoral diaphysis.     

全髋置换术治疗髋关节发育不良

目的探讨髋关节发育不良(DDH)全髋关节置换术的临床方法与疗效。方法对48例DDH继发骨性关节炎的患者(56髋)进行全髋关节置换术。其中CroweⅠ型24髋,Ⅱ型19髋,Ⅲ/Ⅳ型13髋。术前应用影像学方法评估髋臼和股骨的形态学变化。手术采用常规髋关节置换术,恢复髋关节旋转中心35例(40髋),采用自体股骨头结构性植骨重建髋臼旋转中心6例(8髋),髋臼假体内置5例(6髋),高位重建髋臼2例(2髋)。结果 48例均获得随访,时间3个月～8年。关节假体稳定,关节功能正常,双下肢短缩均有明显改善,未出现感染、脱位、神经损伤并发症。Ⅰ、Ⅱ和Ⅲ/Ⅳ型患者按Harris髋关节评分,分别由术前的(47.3±6.5)分、(42.7±5.5)分和(38.6±7.8)分增加到术后的(92.4±4.1)分、(88.2±4.7)分和(83.9±6.6)分,与术前比较差异有统计学意义(P<0.05)。结论对成人DDH按照Crowe分型采用不同方法行全髋关节置换,是一种可靠而有效的方法。充分的软组织松解、重建髋臼和股骨近端的结构以及正确选择假体是手术成功的关键。     

Developmental hip dysplasia treated with total hip arthroplasty with a straight stem and a threaded cup

BACKGROUND: Operative strategies to overcome the anatomical anomalies in patients with osteoarthritis secondary to developmental dysplasia of the hip remain controversial. The objective of this study was to determine the outcomes of total hip replacement with a grit-blasted cementless threaded cup and a cementless straight stem in patients with developmental dysplasia. METHODS: Ninety-three patients with developmental hip dysplasia who had been treated with a total of 121 cementless total hip arthroplasties were clinically assessed at a mean of 9.3 years. The acetabular reconstruction was done with a cementless threaded cup, which was medialized to ensure that at least one thread was anchored in the bone in order to achieve good primary stability. All radiographs were analyzed retrospectively. RESULTS: Kaplan-Meier survivorship analysis, with radiographic evidence of aseptic loosening as the end point, predicted a survival rate of 97.5% for the acetabular component and 100% for the femoral stem at 9.3 years. The average Harris hip score for the unrevised hips improved from 34.0 points preoperatively to 84.1 points at the latest follow-up evaluation. The average total volume of polyethylene wear at the time of final follow-up was 73.6 mm(3). CONCLUSIONS: These wear and loosening rates demonstrate that very good results were achieved in this relatively young patient population when the hip joint center had been properly restored, even when a small cup with a thin polyethylene liner had been used.