Total hip arthroplasty for crowe type ⅳ developmental dysplasia

The purposes of this study were to evaluate the midterm clinical and radiographic results of total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia and to evaluate whether low back pain would improve after THA. Eighteen consecutive patients (20 hips) were included in this study. The average age at the time of surgery was 58.5 years. The average follow-up was 10.2 years. The socket was placed at the level of the true acetabulum, and a femoral shortening osteotomy was performed. The average Harris hip score before surgery was improved from 56 to 85 points at the final follow-up. Revision was performed in 4 hips due to loosening of the femoral component in 1 hip and osteolysis in 3 hips. The midterm outcomes of THA in patients with Crowe type IV developmental dysplasia were satisfactory. The severity of low back pain was significantly reduced after THA.     

Cementless total hip arthroplasty in Chinese patients with osteonecrosis of the femoral head

This study was designed to evaluate the midterm (> or = 5 years) clinical and radiographic outcomes of the cementless total hip arthroplasty in 64 Chinese patients (72 hips), which revealed that the mean Harris hip score increased from an average of 44.0 points before operation to 92.4 points at the last follow-up. Excellent results were achieved in 60 hips (83%). No loosening of the components was observed radiographically. No revision of the femoral components was required. Only one focal area of pelvic osteolysis in 1 hip (1%), which requires a revision, and some small focal areas of femoral osteolysis in 12 hips (17%) were observed. The mean linear wear rate was 0.125 mm/y. The survival rate of the acetabular and femoral components for radiographic loosening was 100% (95% confidence interval, 0.93-1.0) and for revision was 98.61% (95% confidence interval, 0.95-1.0). This study indicated that the cementless total hip arthroplasty in patients with osteonecrosis of the femoral head has a satisfactory midterm clinical and radiographic outcomes, but the long-term effect should be further studied.     

Intermediate-term results after hybrid total hip arthroplasty for the treatment of dysplastic hips

BACKGROUND: In recent studies, good intermediate-term results have been reported after primary hybrid total hip arthroplasty (a cementless acetabular component with a cemented femoral stem) for the treatment of primary osteoarthritis. However, few studies have described the results of this technique in patients with developmental dysplasia of the hip. METHODS: One hundred primary hybrid total hip replacements were performed in ninety patients to treat degenerative arthritis of the hip secondary to developmental dysplasia. Seventy-one patients (eighty-one hips) were available for clinical and radiographic evaluation. The average duration of follow-up was 10.6 years. There were ten men and sixty-one women. Seventy hips were classified as type 1 (dysplasia); seven, as type 2 (low dislocation); and four, as type 3 (high dislocation), according to the classification system of Hartofilakidis et al. RESULTS: At the time of the final follow-up, the average Harris hip score was 86 points. Structural autograft was used in fifteen hips to supplement acetabular coverage. Within five years postoperatively, the acetabular component in six of the fifteen hips had an average of 4.5 mm of vertical migration and an average increase in vertical rotation of 3 degrees, but the position appeared to stabilize thereafter. Revisions were performed in two hips because of recurrent dislocation. No acetabular or femoral component was revised because of aseptic loosening. Osteolysis was identified around two acetabular components and two femoral components. The average rate of polyethylene wear was 0.09 mm per year. CONCLUSIONS: Hybrid total hip arthroplasty for the treatment of symptomatic degenerative arthritis secondary to developmental dysplasia provides favorable results at intermediate-term follow-up. With lower grades of dysplasia, the majority of patients can be treated effectively without a structural bone graft by placement of the cementless acetabular component at a medial or high position.     

成人DDH患者保髋手术失败后的THA疗效分析

目的回顾性分析保髋手术治疗失败后的成人发育性髋关节发育不良患者再次行全髋人工关节置换术的中期疗效。方法选择2014年1月至2019年1月收治的22例(30髋)保髋手术失败后行全髋人工关节置换术(total hip arthroplasty,THA)的发育性髋关节发育不良患者作为研究对象,其中男7例,女15例;行保髋手术时年龄1~18岁,平均(7.9±3.4)岁;行THA时年龄22~63岁,平均(34.2±11.2)岁;单髋14例,双髋8例,左髋16侧,右髋14侧。手术前后采用Harris髋关节评分系统及疼痛视觉模拟评分法(visual analogue score,VAS)进行评价,并对手术前后的X线片进行分析。结果本研究病例全髋人工关节置换术后平均随访时间为(30.5±18.5)个月。全髋人工关节置换术后,Harris总评分从术前的平均(38.7±10.6)分提高至末次随访时的(89.4±9.7)分,差异有统计学意义(t=19.67,P<0.001),且患者的疼痛、行走、功能、活动度等各项指标的术后评分均高于术前且差异有统计学意义;疼痛VAS评分由术前的平均(7.9±0.9)分降低到末次随访时的(1.4±1.0)分,差异有统计学意义(t=30.67,P<0.01);患者双下肢长度差异由术前的平均(3.32±0.51)cm降低到术后(0.71±0.33)cm,差异有统计学意义(t=14.01,P<0.001)。所有患者均无发生手术切口及假体周围感染、假体松动、髋关节脱位、血管神经损伤、深静脉血栓及异位骨化等术后并发症,仅2例患者术中出现股骨近端纵行劈裂。结论保髋手术失败后的成人发育性髋关节发育不良患者行全髋人工关节置换术可获得满意的中期疗效。     

Total hip arthroplasty with a cementless acetabular component and a cemented femoral component in the treatment of Chinese patients with femoral head necrosis

The purpose of this study was to evaluate midterm clinical and radiographic outcomes associated with hybrid total hip arthroplasty in a consecutive series of 86 Chinese patients (93 hips) with osteonecrosis of the femoral head, which revealed that the mean Harris hip score increased from 39 +/- 6.0 points before operation to 90.4 +/- 4.6 points at the latest follow-up. There was pelvic osteolysis in one hip (1%), which required revision, and some small focal areas of femoral osteolysis in 12 hips (13%) were observed. The mean linear wear rate was 0.143 +/- 0.05 mm/y (0.02-0.45 mm/y). No loosening of the components was observed radiographically. The survival rate of the acetabular and femoral components for revision was 98% (95% confidence interval, 0.96-1.0) and 100% (95% confidence interval, 0.95-1.0). Hybrid total hip arthroplasty in patients with osteonecrosis of the femoral head had a satisfactory clinical and radiographic outcome at a minimum 5 years of follow-up. Because polyethylene wear and osteolysis cannot be avoided, the long-term effect should be further studied.     

联合前倾角技术在成人发育性髋关节发育不良全髋关节置换术中的应用

目的探讨联合前倾角技术在成人发育性髋关节发育不良全髋关节置换术中应用的可行性及临床价值。方法回顾性分析自2016-09—2018-06采用联合前倾角技术行全髋关节置换术治疗的31例(36髋)成人发育性髋关节发育不良,比较手术前后髋臼前倾角、股骨前倾角、联合前倾角及髋关节功能Harris评分。结果31例均获得12个月以上随访。术后骨盆正位及髋关节侧位X线片显示假体位置及对应关系良好,无假体松动、下沉,无脱位表现。末次随访时所有患者步态均明显改善,髋部疼痛均消失,仅2例轻度跛行。术后髋臼前倾角、股骨前倾角、联合前倾角较术前明显减小,末次随访时髋关节功能Harris评分较术前明显增加,差异有统计学意义(P<0.05)。结论联合前倾角技术应用于成人发育性髋关节发育不良全髋关节置换术对于指导合适假体的选择、设计以及确定合适的髋臼前倾角、股骨柄前倾角具有重要意义,良好的联合前倾角能够有效预防术后假体脱位的发生。     

自体股骨头重建髋臼治疗髋关节发育不良的中期疗效

 目的 总结采用自体股骨头结构性植骨治疗髋关节发育不良继发关节炎的中期疗效及并发症。方法 回顾性分析2001年10月至2011年12月采用自体股骨头重建髋臼方法治疗36例髋关节发育不良患者资料,其中34例获得30个月以上的临床及影像学完整随访资料,男6例,女28例;年龄28~68岁,平均51岁;均为单侧手术,左侧16例,右侧18例。Crowe分型,Ⅱ型12例,Ⅲ型16例,Ⅳ型6例;所用假体除1例为混合型外,其余均为非骨水泥型。临床随访包括术前、术后Harris评分及各种并发症;影像学评估包括双侧髋关节正位（或骨盆正位）、患侧髋关节侧位X线片,以判断人工假体位置、植骨愈合情况。结果 34例患者均获得随访,随访时间31~153个月,平均64.1个月。术前Harris评分为23~56分,平均35.4分;末次随访时为82~95分,平均89分,其中优28例,良6例,优良率为100%。术后2~8个月,10例出现植骨块吸收。术后4例患者发生髋关节假体脱位,遂均采用闭合复位,其中1例于复位后2个月再次发生脱位,再次采用闭合复位后未再发生脱位;另3例均未再发生脱位。1例患者于术后3个月摔倒后出现假体周围骨折,行骨折切开复位钢板内固定术,1年随访时骨折已愈合,至末次随访时假体及内固定位置良好、骨折愈合良好,患髋功能良好。术后1年,1例患者因高血压颅内出血行保守治疗后关节置换侧偏瘫,关节失用。结论 自体股骨头重建髋臼治疗髋关节发育不良整体疗效满意,骨吸收是结构性植骨的一个自然过程,关节脱位是髋关节发育不良全髋置换术后的最常见并发症。     

全髋关节表面置换术治疗成人髋关节发育不良25例中期随访

目的探讨全髋关节表面置换术（total hip resurfacing arthroplasty,THRA）治疗成人髋关节发育不良（developmental dysplasia of the hip,DDH）继发骨关节炎的中期疗效。方法2005年3月至2006年6月,采用THRA治疗DDH患者25例,女18例,男7例;30～59岁,平均48岁;双髋1例,共26髋。根据Hartofilakidis分型,半脱位22髋,低位脱位4髋。采用Conserve-plus金属对金属全髋关节表面置换假体,髋臼假体为非骨水泥固定,股骨头假体采用低黏骨水泥固定。临床随访采用Harris评分,测量髋臼外展角、垂直距离、水平距离、股骨柄干角、髋臼假体覆盖率;记录髋臼和股骨假体周围透亮线及骨溶解;以各种原因所致翻修或影像学松动为随访终点。结果所有患者均随访3年以上,平均随访3.5年。截至随访终点无翻修或影像学松动。患者的Harris评分由术前平均46分提高至术后平均92.1分,26髋均为优。术后轻度跛行2例,所有患者均无迟发感染、术后股骨颈骨折、术后残余股骨头坏死、术后假体松动、脱位、术后异位骨化。髋关节活动度：屈曲由97.5°增加至127.5°,外展由19.3°增加至40°,外旋由23.2°增加至42.5°,内旋由4.2°增加至28.5°。X线片显示：关节假体位置正常,髋臼假体平均外展角为41.6°,髋关节旋转中心位置平均下移6.2 mm、内移15 mm,股骨柄干角平均146.4°。宿主骨对臼杯的平均覆盖率为94.4%,1例宿主骨与臼杯界面在2区出现透亮线,宿主骨与股骨假体柄界面无一例出现透亮线。结论THRA治疗成人半脱位型及低位脱位型DDH继发骨关节炎具有良好的中期疗效,熟练的手术技术和正确的适应证选择是降低中远期并发症的关键。     

国产表面多孔解剖型全髋关节置换术的远期随访结果

目的 评估国产表面多孔解剖型全髋关节置换术的远期疗效.方法 1990年1月至1998年4月接受国产表面多孔解剖型全髋关节置换术的95例患者经电话核实、预约及直接去患者家中随访,同时在当地医院拍摄标准髋关节正侧位X线片.随访指标:依据Harris评分评价临床疗效,应用Gruen和DeLee & Chamley分区法对股骨柄和髋臼杯的正侧位X线影像进行分析.结果 50例失随访,16例死亡.29例(37髋)得到随访,随访时间11～17年,平均13.8年.随访时4例4髋已得到翻修,其余患者随访时Harris评分6～98分,平均70.3分;其中优7例10髋,良4例6髋,中5例7髋,差9例10髋,优良率48.5%.6髋(18.2%)需行翻修,主要原因为假体无菌性松动及移位.按照Harris评分标准,患者术髋无疼痛或轻度疼痛18例,中度以上疼痛6例(偶服比阿司匹林强的镇痛剂),病废1例(因疼痛被迫卧床,卧床也有剧痛).X线片显示股骨柄下沉9髋,平均下沉9.3mm;股骨柄周围出现透光带12髋;股骨柄周围骨溶解10髋;髋臼假体侧出现透光带13髋;假体多孔表面层有不同程度脱落2髋.结论 20世纪90年代应用的国产表面多孔解剖型全髋关节置换术可有效改善患者功能,但其远期疗效还有待进一步提高.假体无菌性松动是其最主要的远期并发症.     

全髋关节表面置换术的近期疗效观察

目的评价全髋关节表面置换术治疗髋关节疾病的近期疗效。方法回顾性分析2006年10月至2008年4月行全髋关节表面置换术患者38例45髋,男18例22髋,女20例23髋;年龄24～74岁,平均42．5岁。股骨头坏死28例31髋（Ficat分期均为Ⅱ-Ⅲ期）,强直性脊柱炎髋关节病变7例11髋,髋臼发育不良继发骨关节炎2例2髋,创伤性髋关节炎1例1髋。患者均为首次接受髋关节手术治疗,均无严重心血管疾病,术前均存在严重髋关节疼痛与活动受限,且1年以上保守治疗无效。术前VAS评分6—10分,平均（8．21±1．25）分;术前Harris评分30～45分,平均（36±7．85）分。采用金属对金属表面髋假体（metal on metal suvface arthroplasty,MMSA）进行治疗。结果随访时间6—25个月,平均14个月。随访期间无一例发生严重并发症。术后VAS评分改善至0～4分,平均（1．52±1．16）分,与术前相比差异有统计学意义（t=26．32,P〈0．01）。术后Harris评分增至84—98分,平均（93±5．25）分,与术前相比差异有统计学意义（t=40．49,P〈0．01）。其中优39髋,良6髋,优良率100％。结论全髋关节表面置换术治疗年轻患者和对运动要求较高的老年患者的近期疗效满意,术后髋关节疼痛和髋关节功能明显改善。     

Straight tapered titanium stem with alumina bearing in cementless primary total hip arthroplasty: a minimum 5-year follow-up

The aim of this study was to assess the midterm results of primary cementless total hip arthroplasty using a tapered stem and alumina bearing couple in active patients. After a minimum of 5 years of follow-up, 78 arthroplasties in 72 patients were reviewed retrospectively. The mean Harris hip score was 94 points, and 2 hips had thigh pain. All components radiographically demonstrated stable fixation by bone ingrowth and mild stress shielding of the proximal femur were noted in 14% of hips. There was no significant osteolysis or aseptic loosening. There was a ceramic head fracture in 1 hip and audible sounds in 2 hips. The results of total hip arthroplasty with a straight, tapered, proximally porous-coated stem and alumina-on-alumina bearing were encouraging for active patients.     

Hybrid total hip arthroplasty using specifically-designed stems for patients with developmental dysplasia of the hip. A minimum five-year follow-up study

A 4-U hybrid total hip arthroplasty (THA) system was specifically designed for patients with developmental dysplasia of the hip (DDH). Straight stem with an appropriate offset and various size variations are advantages. We followed 128 hips in 124 patients, 13 men and 111 women, for a mean of 6.5 years (range, 5.0–7.5 years). Two acetabular and femoral components in two patients had been revised for infection, one acetabular component had been revised for recurrent dislocation, and one femoral component had been revised for periprosthetic femoral fracture. None of the acetabular or femoral components were revised for loosening or were found to be loose at follow-up. The Harris hip score increased from a preoperative average of 42 points to 88 points at the most recent follow-up. Primary THA using the 4-U system had a good mid-term result in patients with DDH. This system could be applied for all patients including those with the narrowest and deformed femurs.     

全髋翻修术后假体脱位的预防

目的：探讨采用后方关节囊重建方法对行后外侧入路全髋翻修术后假体脱位的防治作用。方法：本组45例（47髋）经后外侧入路行全髋翻修术的患者，男20例，女25例；平均年龄65岁（55-78岁）。术中将后方关节囊与外旋肌群分别重建固定于前上方原先切开的关节囊断端和大转子顶端的软组织处，回顾性分析术后假体脱位率及脱位的风险因素。股骨假体和髋臼假体均翻修29例（31髋），更换内衬5例（5髋），髋臼、股骨翻修的分别是10例（10髋）和1例（1髋）。第1次翻修的有29例（30髋），第2次翻修的有15例（16髋），第3次翻修的有1例（1髋）。X线评估包括翻修前后下肢长度，髋臼位相，股骨偏心距、前倾角和假体松动。临床功能评价采用Harris评分。结果：45例均获随访，平均随访时间2．7年，除1例感觉前方不稳外，无髋关节感染及脱位发生，该例X线片示髋臼假体过度前倾但无脱位发生。术后所有患者双下肢基本等长，髋臼外展角及前倾角、股骨偏心距和前倾角基本恢复至初次手术前水平。髋臼、股骨假体发生松动各1例。髋关节功能Harris评分由术前平均（49.13±15．53）分升至末次随访的平均（83．59±6.93）分（P〈0．05）。按Harris功能评分标准：优36髋，良5髋，可5髋，差1髋。结论：在假体安放正确、软组织张力恢复满意基础上，后方关节囊及外旋肌群重建有助于降低后外侧入路全髋翻修术后假体脱位的发生率。     

Total hip arthroplasty with a collarless, tapered, fiber metal proximally coated femoral stem: minimum 5-year follow-up

The purpose of this study was to evaluate the midterm results, osteointegration potential, and implant-related complications of a cementless, collarless, proximally coated, distally tapered femoral hip prosthesis. The clinical and radiographic results for 129 hips in 116 patients after total hip arthroplasty with a Fiber Metal Taper (Zimmer, Inc ,Warsaw, Ind) femoral stem are reported. One hundred twenty-two (95%) hips were available for the minimum of 5 years clinical and radiographic follow-up. The mean duration of follow-up was 81 months (range, 60-104 months). The mean Harris hip score improved from 44 to 92 at the most recent follow-up. All femoral components were clinically stable with radiographic evidence of bone ingrowth. There has been no evidence of subsidence greater than 2 mm, no significant thigh pain, and no femoral revisions for any reason. Total hip arthroplasty with the Fiber Metal Taper stem demonstrates good clinical and radiographic results at midterm follow-up.     

Cementation of Cross-linked Polyethylene Liner Into Well-Fixed Acetabular Shells : Mean 6-Year Follow-Up Study

The purpose of this study was to evaluate retrospectively the outcomes of cementation of cross-linked polyethylene (PE) liner in a well-fixed metal shell in 23 hips with an average follow-up period of 6 years. The mean Harris hip score was 69.6 ± 12 (range, 46-83) points preoperatively. The average postoperative follow-up was 72.3 months (range, 56-100 months). At the final follow-up, the mean Harris hip score was 95.5 ± 3 (84-100) points. There was no change in the bone-shell interface. No new osteolytic lesions were identified. The lesions impacted with bone graft had united completely. The remaining osteolytic lesions had decreased in size. There was no recurrent osteolysis, hip dislocation, component migration, and failure at the cement-metal interface. The results of the current study revealed that cementation of cross-linked PE liner into a well-fixed shell provided good midterm durability.     

全髋关节置换术治疗成人髋关节发育不良

目的探讨全髋关节置换术(THA)治疗成人髋关节发育不良的临床疗效。方法采用THA治疗45例髋关节发育不良患者(50髋)。记录术后感染、髋关节脱位、假体松动、神经损伤情况,末次随访时采用Harris评分评定髋关节功能。结果患者均获得随访,时间2~65(24.1±16.0)个月。术后无感染、髋关节脱位、神经损伤等并发症发生。Harris评分由术前7~77(38.0±15.4)分增加到末次随访68~96(87.2±6.0)分,末次随访与术前比较差异有统计学意义(P<0.05)。末次随访时,所有患者患侧髋关节疼痛症状消失,关节活动功能满意;摄髋关节X线片复查显示关节假体位置、宿主骨对臼杯覆盖良好,假体骨骼界面稳固、无松动。结论THA治疗成人髋关节发育不良疗效满意,术中髋臼处理、真臼重建以及股骨假体的选择与安放是手术成功的关键因素。     

Cementless Total Hip Arthroplasty With Modified Oblique Femoral Shortening Osteotomy in Crowe Type IV Congenital Hip Dislocation

Midterm results of cementless total hip arthroplasty in patients with Crowe type IV congenital dislocation of the hip were evaluated. A modified oblique subtrochanteric shortening osteotomy was used in all patients. A cylindrical femoral stem was used in all patients to stabilize the osteotomy. Mean follow-up was 82 months in 20 hips of 16 patients. Mean Merle D'Aubigné pain score increased from 2.52 to 5.65 points, function score improved from 4.0 to 5.3 points, and mobility score improved from 3.95 to 5.35. Mean greater trochanter height relative to the estimated hip center was 6.8 ± 2.0 cm preoperatively and − 1 ± 0.2 cm postoperatively. Complications were dislocations in 3 patients, which were successfully managed without redislocation and fracture of greater trochanter in 3 patients, which healed uneventfully in 2 but with residual Trendelenburg gait in one. Total hip arthroplasty with modified oblique subtrochanteric shortening osteotomy is an effective technique for the treatment for Crowe type IV hip dislocation.     

关节置换术后感染非组配式广泛涂层股骨柄二期翻修术的中期疗效

 目的 探讨应用非组配式广泛涂层股骨柄行关节置换术后感染二期翻修术的中期疗效。方法 回顾性分析2005年3月至2006年12月接受全髋关节置换术后感染二期翻修的33例（33髋）患者的病例资料,男20例,女13例;年龄52~80岁,平均（66.1±7.2）岁。二期翻修方案包括一期取出关节假体,彻底清创,置入自制抗生素骨水泥间隔体,抗感染治疗后行二期关节翻修术。抗感染治疗包括静脉抗感染治疗4周、口服抗生素6周。采用美国骨科医师学会（American Academy of Orthopaedic Surgeons,AAOS）分类法评估髋臼骨缺损,Paprosky分类法评估股骨骨缺损。采用Harris髋关节评分评估髋关节功能,术后定期复查X线片评估假体稳定性、移位、松动情况。根据DeLee和Charnley分区法记录髋臼假体周围透光线,根据Gruen分区法记录股骨柄周围透光线。采用Engh等标准评价股骨假体固定情况。再感染的标准与诊断关节感染的标准相同。结果 全部病例随访5~9年,平均（6.1±1.7）年。二期翻修术后无一例出现感染或假体松动。二期翻修术中所取标本微生物培养或病理学检查均为阴性。Harris髋关节评分由术前（42.3±6.5）分提高到末次随访的（89.1±8.5）分。股骨柄骨长入固定30例,纤维稳定固定3例。11例髋臼侧打压植骨和所有股骨髓腔内打压植骨均与宿主骨融合。股骨侧异体皮质骨板移植者10例,9例于二期翻修术后1年与宿主骨融合、1例于术后2年融合。结论 采用非组配式广泛涂层股骨假体行感染二期翻修结合髓腔内颗粒骨打压植骨能取得较好的假体中期生存率和感染清除率。     

股骨矢状位劈开固定股骨假体在全髋关节置换治疗 Crowe Ⅳ型成人髋关节发育不良中的应用观察

目的：探讨股骨矢状位劈开固定股骨假体在全髋关节置换治疗成人髋关节发育不良（ CroweⅣ型）患者术后的疗效分析。方法2002年3月～2012年11月,本组在全髋关节置换术中以股骨矢状位劈开固定股骨侧假体治疗重度成人髋臼发育不良（ Crowe Ⅳ型）患者共21例24髋,股骨上移4.5～6.9 cm,平均（4.53±0.89） cm。术前Harris 评分（38.21±3.09）。结果21例（24髋）患者获随访,截骨端均骨性愈合,平均愈合时间3.8个月;术后6个月Harris评分（85.73±4.15）分,与术前比较差异有统计学意义（t＝-104.2,P＜0.05）。随访期间均无感染、脱位、假体翻修等并发症出现。结论股骨矢状位劈开固定股骨假体在全髋关节置换治疗成人髋关节发育不良（ CroweⅣ型）患者的手术效果稳定,手术技术具有可重复性,能够获得满意的疗效,可在临床中广泛推广。     

Total hip arthroplasty with insertion of the acetabular component without cement in hips with total congenital dislocation or marked congenital dysplasia

BACKGROUND: End-stage osteoarthritis secondary to total congenital dislocation or severe congenital dysplasia of the hip (class B or C according to the system of Eftekhar or type 2 or 3 according to the system of Hartofilakidis et al.) in adults presents special problems with regard to reconstruction of the hip. The purpose of the present study was to assess the intermediate-term results associated with the use of a porous ingrowth acetabular component for the treatment of these difficult cases. METHODS: We performed a prospective study of a consecutive series of twenty-one patients (twenty-four hips) who had had a primary total hip arthroplasty with use of a hemispherical acetabular component that was inserted without cement and fixed with screws. No patient was lost to follow-up. Three patients (four hips) died, of causes unrelated to the total hip arthroplasty, before a minimum duration of follow-up of five years. None of these patients had had revision. Of the remaining eighteen patients (twenty hips), fifteen were women and three were men. Ten hips had total dislocation, and ten had severe dysplasia. RESULTS: After an average duration of follow-up of eighty-three months (range, sixty-four to 102 months), the average Harris hip score was 90 points (range, 68 to 97 points). No patient had revision, loosening, or migration of the acetabular component; pelvic osteolysis; or a continuous radiolucent line at the mesh-bone interface of the acetabular component. The average rate of polyethylene wear was 0.08 millimeter per year (range, zero to 0.21 millimeter per year). CONCLUSIONS: The porous ingrowth acetabular component that was used in the present study functioned well at the time of the intermediate-term follow-up of this group of patients who had marked congenital dysplasia or total dislocation of the hip. The use of this component decreased the need for structural acetabular grafts. This component appears to perform as well as larger components of this design that have been assessed after similar durations of follow-up.