Accurate limb-length equalization during total hip arthroplasty

A method of equalization of limb lengths during total hip arthroplasty (THA) was developed that uses the concept of precise reproduction of the position of the femur in space (abduction/adduction) by use of a carpenter's level. Precise reproduction of the femoral position allows accurate measurement of the distance between the pelvis and femur before hip dislocation and after trial component placement allowing accurate measurement of the change in the distance between the femur and pelvis. Accordingly, limb length can be maintained or adjusted to match the contralateral side with increased accuracy. A prospective study was performed with 117 consecutive patients undergoing THA to assess the accuracy of an intraoperative limb-length measuring device. Patients were sequentially randomized into two groups. Group A patients underwent THA without the use of the measuring device, and group B underwent THA using the device. Radiographic assessments of limb lengths were measured using the method of Williamson and Reckling. The hips in group B had a statistically significant decrease in limb-length inequality after THA compared with group A (P<.01). Average postoperative limb-length inequality was 8.8 mm and 3.4 mm for groups A and B, respectively. Three (5%) of 58 group B patients and 18 (31%) of 59 group A patients had a radiographic postoperative limb-length inequality >12 mm (P<.01). Eighty-four of group B patients had limb lengths within 6 mm of the contralateral side compared with 30% of group A patients. Twenty-four percent of group A patients and 7% of group B patients had a symptomatic limb-length inequality that required a heel lift (P<.01).     

Cementless total hip arthroplasty in patients with high congenital hip dislocation

BACKGROUND: The optimal surgical treatment for patients with high congenital dislocation of the hip remains controversial. The purpose of our study was to evaluate the mid-term to long-term results of cementless total hip arthroplasty in such patients. METHODS: The study included sixty-eight total hip replacements performed between 1989 and 1994 in fifty-six consecutive patients with high congenital hip dislocation at our hospital. The cup was placed at the level of the true acetabulum, and a shortening osteotomy of the proximal part of the femur and distal advancement of the greater trochanter were performed in 90% of the hips. At the time of final follow-up, at a mean of 12.3 years postoperatively, fifty-two patients (sixty-four hips) were evaluated by us with a physical examination, determination of Harris hip scores, and radiographs. RESULTS: The mean Harris hip score increased from 54 points preoperatively to 84 points at the time of final follow-up (p < 0.001). There was a negative Trendelenburg sign in fifty-nine (92%) of the sixty-four hips. There were thirteen perioperative complications (19%): three peroneal nerve palsies, one femoral nerve palsy, one superior gluteal nerve palsy, four nondisplaced fractures of the proximal part of the femur, one malpositioned stem perforating the posteromedial cortex of the femur, one superficial wound infection, and two early dislocations. With revision because of aseptic loosening as the end point, the ten-year survival rate for press-fit, porous-coated acetabular components was 94.9% (95% confidence interval, 89.3% to 100%). Eight of nine threaded acetabular components were revised, and the ninth was radiographically loose at the time of the last follow-up examination. The rate of survival for the CDH femoral components, with revision because of aseptic loosening as the end point, was 98.4% (95% confidence interval, 96.8% to 100%) at ten years. CONCLUSIONS: Total hip arthroplasty, with placement of the cup at the level of the true acetabulum, distal advancement of the greater trochanter, and femoral shortening osteotomy, can be recommended for patients with high congenital hip dislocation. Complications such as wear, osteolysis, and cup revision were secondary to the suboptimal design of the acetabular components used in this series.     

非骨水泥型全髋关节置换治疗成人高位发育性髋脱位

目的：分析和总结成人高位发育性髋脱位患者的非骨水泥型全髋关节置换手术方法及疗效。方法：对1999年5月～2002年7月接受Zweymuller非骨水泥型全髋关节置换术的9例(11髋)成人高位发育性髋脱位患者进行随访。男1例，女8例，平均年龄29．4岁，均为Hartofilakidis Ⅲ型。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40．2分。双下肢长度差异平均4．1cm,脱位高度平均4．8cm。术中臼杯均安装于真臼处，臼杯骨量覆盖80％以上。脱位高度5cm以上4髋，采用股骨小转子下截骨，余7髋经单纯软组织松解后复位。结果：平均随访18．2个月。临床症状基本消失，双下肢长度差异平均1．1cm。1例术中股神经不全损伤，术后4个月恢复。Harris评分平均90分。所有患者最后随访时对治疗结果满意。结论非骨水泥型全髋关节置换对成人高位发育性髋脱位的治疗是一种较理想的方法，能很大程度地改善患者的生活质量。脱位高度小于5cm者，经软组织松解后能完全下拉复位，不会造成股神经及坐骨神经永久性麻痹。手术操作相对简单，即使发生松动也便于翻修。     

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。     

Spinopelvic alignment does not change after bilateral total hip arthroplasty in patients with bilateral Crowe type-IV developmental dysplasia of the hip

ObjectiveThis prospective study aimed to evaluate the changes in the sagittal alignment after total hip arthroplasty (THA) in patients with hip osteoarthritis (OA) secondary to Crowe type-IV developmental dysplasia of the hip (DDH) and whether THA would contribute to the relief of low-back pain (LBP).MethodsA total of 27 patients (2 men and 25 women) with bilateral hip OA secondary to Crowe type-IV DDH were enrolled in this study. Their mean age at the time of surgery was 40,36±12,35. All patients underwent simultaneous, bilateral THA between January 2015 and December 2016. Clinical assessment included Oswestry disability index (ODI) score and Harris hip score (HHS), and pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and pelvic tilt (PT) were measured from radiographs.ResultsPreoperatively, all the patients had hip and low-back pain. Preoperative and final follow-up ODI scores were 48.3 and 3.9 (p=0.000), respectively. HHS changed from 43.54 to 92.68 (p=0.000). PT and PI significantly changed from −20.4°±20.4° to 3.2°±16.7° (p=0.001) and from 26.6°±35.1° to 47.4°±17.9° (p=0.001), respectively. There were no significant differences regarding the SS and LL measurements. Age or limb-length discrepancy was not significantly associated with the spinopelvic alignment measurements.ConclusionRestoring the function of the hip with THA is shown to improve hip-associated LBP, but the accompanying hyperlordosis does not change. THA in patients with bilateral Crowe type-IV hips relieves hip pain as well as associated LBP. Hyperlordosis of the lumbar vertebra does not change after surgery, but PI and PT changes are observed; this improvement might have a role in the relief of LBP.Level of EvidenceLevel IV, Therapeutic study     

股骨转子下叠加缩短截骨在CroweⅣ型成人髋脱位全髋置换术的应用

目的总结CroweⅣ型成人髋脱位采用股骨转子下叠加缩短截骨行全髋置换术的方法与疗效。方法2000年1月至2003年12月，收治8例（11髋）CroweⅣ型成人髋脱位患者，男3例，女5例；年龄40-57岁，平均48岁；单髋5例，双髋3例；先天性发育不良7例，陈旧性髋关节结核1例。假体臼杯为金属杯＋聚乙烯内衬设计，其中Duraloc（Depuy，Warsaw，USA）8髋，Pressfit SⅡ（LINK，Ger-many）3髋。股骨柄假体采用AML（Depuy，Warsaw，USA）4髋，Summit（Depuy，Warsaw，USA）4髋，Ribbed（LINK，Germany）3髋。假体均采用生物学固定。手术均采用股骨转子下叠加缩短截骨，并附加断端“V”形截骨，其中6髋因最小号股骨柄假体置 入困难，而附加股骨劈开成形术。结果无一例发生感染、脱位等并发症，无一例行臀大肌或臀中、小肌等短肌松解。转子下平均缩短截骨长度为4．5cm（4～6cm），无一例因截骨过短，导致股骨头假体复位困难或坐骨神经牵伸伤；也无一例因截骨过长，导致股骨头假体松弛性脱位。术后X线片示臼杯均位于真臼区，股骨柄假体的初始固定均优良，截骨断端在3～6个月后均骨性愈合。测量显示患肢平均延长3cm（2．5～3．5cm）。随访3～7年，髋关节Harris评分从术前的25～32分改善至1年后的90～98分。无一髋假体显示有X线松动和邻近骨溶解。结论股骨转子下叠加缩短截骨术可用于CroweⅣ型成人髋脱位的全髋置换术治疗。     

Cementless total hip arthroplasty with PCA prosthesis

Eighty-one cases of cementless porous-coated total hip arthroplasties in 74 patients were analyzed. Hip rating scores as described by Harris were used, and AP and lateral radiographs were made serially: preoperatively, 3 months, 6 months, 1 year, and 2 years postoperatively. The average postoperative hip rating score was 91 points (range: 76 to 100 points) at 1 year and 93 points (range: 74 to 100 points) at 2 years. The overall clinical results were satisfactory in these patients at both 2 and 4 years. However, slight to mild thigh pain was observed in 16 (19.8%) of 81 hips at 2 years, and 10 (21.3%) of 47 hips at 4 years postoperatively. Moderate to severe limp was seen in 11 (13.6%) of 81 hips at 2 years and seven (14.9%) of 47 hips at 4 years postoperatively.     

Cementless total hip arthroplasty in renal transplant patients.

Twenty-seven cementless total hip arthroplasties were performed in 17 steroid-dependent renal transplant patients. The average age at operation was 39 years, and the average daily dose of prednisone was 10.9 mg. At a mean of 48 months post-surgery, all patients had good to excellent hip ratings on clinical examination and the results compared favorably with 235 non-steroid-dependent age-matched patients using the identical prosthetic hip system. The results of this study suggest that long-term immunosuppression does not prevent bone ingrowth. Noncemented total hip arthroplasty appears to be a reasonable therapeutic option for end-stage osteonecrosis in steroid-dependent renal transplant patients.     

Gait analysis after total hip arthroplasty with leg-length equalization in women with unilateral congenital complete dislocation of the hip--comparison with untreated patients.

Patients with Crowe Type-IV congenital dislocation of the hip (CDH) show significant clinical improvement after total hip arthroplasty (THA) because this surgery greatly reduces pain. Concomitant leg-length equalization in unilateral patients--a controversial procedure--theoretically should significantly improve these patients' ability to walk efficiently and comfortably. To understand the impact of leg-length equalization on these patients, we compared their gait parameters with those of untreated patients without pain but with leg-length discrepancy. Using a motion analysis system, three force platforms and computer calculation, the gait parameters during level walking of 22 women with unilateral Crowe Type-IV CDH were studied at an average of 58 months (27-98 months) following a successful cementless THA. The socket was placed in the best bone stock, which was close to the level of the true acetabulum. The leg-length discrepancy was equalized to within 2 cm in all patients. The Harris hip score averaged 94.8 (range, 88-100) at the time of the study. Nine women with untreated unilateral Crowe Type-IV CDH without major pain but with an average leg-length discrepancy of 4.7 cm (range, 2.5-6 cm) were also studied for comparison. The treated subjects (Group 1; THA and leg-length equalization) walked faster and had gait parameters with better bilateral symmetry than the untreated subjects (Group 2). We concluded that leg-length equalization in addition to THA in patients with unilateral Crowe Type-IV CDH significantly improves gait symmetry and efficiency.     

转子下截骨短缩全髋关节置换治疗髋关节发育不良

目的探讨股骨转子下截骨短缩人工髋关节置换治疗成人CroweIV型髋关节发育不良的临床疗效。方法CroweIV型髋关节发育不良患者18例24髋，均为女性，平均年龄46．8岁（38-55岁）。采用S-ROM或AML假体结合股骨转子下横断截骨短缩行人工关节置换术，按术前计划、股骨重叠情况及软组织和坐骨神经张力截除相应长度股骨。术前、术后行Harris评分及功能评价。结果全部病例随访9-72个月，平均29个月。Harris评分由术前41分增加到术后89分，优良率83．3％。髋旋转中心平均下降56mm，平均截骨短缩长度为31mm。截骨平均愈合时间为8个月。1髋术中、2髋术后并发股骨骨折，发生率12．5％，用加压钢板及钢丝固定，平均10个月后骨折愈合。术前Trendelenburg征均为阳性，术后15例阴性、3例阳性，转阴时间平均为13个月。单侧患者肢体不等长发生率为25％。无一例出现关节感染、假体松动、脱位、神经功能损伤等并发症。结论股骨转子下截骨短缩人工髋关节置换治疗髋关节发育不良高位脱位可避免坐骨神经损伤，单侧患者易形成肢体不等长，软组织平衡及肌力恢复需要一定时间，Trendelenburg征转阴时间长，易并发术中及术后股骨骨折，需用钢丝环扎预防。     

Cementless femoral fixation in total hip arthroplasty

A number of cementless femoral stems are associated with excellent long-term survivorship. Cementless designs differ from one another in terms of geometry and the means of obtaining initial fixation. Strict classification of stem designs is important in order to compare results among series. Loosening and thigh pain are less prevalent with modern stem designs. Stress-shielding is present in most cases, even with newer stem designs.     

Correction of limb-length inequality during total hip arthroplasty

Although several methods of intraoperative limb-length measurements have been described, their success in predicting the limb-length correction is not well documented. A new technique of measuring intraoperative limb lengthening using a vertical Steinmann pin at the infracotyloid groove of the acetabulum was studied in 100 consecutive primary total hip arthroplasties. Correlation of the predicted intraoperative correction was done with the postoperative radiographic measurements. Preoperative limb-length inequality ranged from -24 mm (short) to +2 mm (long) (mean, -4.2 mm). Intraoperative measurement of lengthening ranged from 0 to 15 mm (mean, 5.9 mm). Radiographic measurements of postoperative radiographs showed lengthening ranging from 0 to 17 mm (mean, 7.4 mm). There was significant correlation between the 2 values (r =.84). Postoperative limb-length inequality ranged from -7 mm to +8 mm (mean, 1.9 mm). None of the patients had to use shoe lifts for equalization of limb lengths.     

Cementless total hip arthroplasty in patients 50 years or younger

This report examines the mean 9-year results of 100 second-generation cementless total hip arthroplasty in 91 patients 50 years or younger. The mean age at arthroplasty was 39 years (range, 14-50 years), and follow up averaged 9 years (range, 5-13 years). There were 13 revisions (7 related to polyethylene wear and/or osteolysis, 5 for instability, and 1 for infection). No femoral components were revised for loosening and none were radiographically loose. Two acetabular shells were revised for loosening secondary to extensive osteolysis. Ten-year survivorship using revision for any reason as the end point was 87.5%, using femoral component aseptic loosening as the end point was 100%, and using acetabular component aseptic loosening as the end point was 97.1%.     

非骨水泥型全髋关节假体治疗强直性脊柱炎

目的:评价非骨水泥型全髋假体治疗强直性脊柱炎中期疗效。方法:对29例(33髋)选用非骨水泥型全髋假体行全髋置换术的强直性脊柱炎患者进行随访,年龄34～57岁,平均42.4岁,术后随访2.2～5.6年(平均为4.3年)。对手术前后关节疼痛、活动度、畸形矫正、松动及患者整体功能的改善情况进行对比研究,临床随访根据Har-ris系统进行评分比较。结果:本组失访5例,术后除6侧髋关节轻度疼痛,2侧髋关节明显疼痛外,其余关节均无疼痛。关节活动度由术前平均46.5°改善为术后75.2°。髋关节屈曲畸形由术前平均32.6°改善为7.5°。术前Harris评分18～65分,平均44分;术后68～92分,平均86分。术后所有患者生活均可自理或部分自理。术中及术后并发症包括:股骨上端微型劈裂骨折5例,坐骨神经损伤1例,术后2个月脱位1例,股骨假体下沉4例,异位骨化4例。结论:使用非骨水泥型假体行全髋置换术是治疗强直性脊柱炎的一种可靠而有效的方法。     

Subtrochanteric shortening with overlapping femoral resection in total hip arthroplasty for Crowe type IV adult dislocation of the hip

Objective: To summarize the surgical technique and clinical outcomes of subtrochanteric shortening with overlapping femoral resection in primary total hip arthroplasty (THA) for Crowe type IV adult dislocation of the hip (ADH). Methods: From January 2000 to December 2005, 12 patients with ADH (15 hips) were treated with primary cementless hip arthroplasty using the method of subtrochanteric shortening with overlapping femoral resection. There were three male and nine female patients (nine unilateral and three bilateral hips) with an average age of 56 years (range, 41–75). Subtrochanteric shortening with overlapping femoral resection and ‘V’ shaped derotational osteotomy were performed in all cases without soft tissue cutting release. Proximal femoral shaft splitting was performed as an adjunct in 10 hips. Results: The mean follow‐up time was 6 years (range, 3–8). There were no infections, nonunion, malunion, dislocation or nerve injury of traction. Postoperative X‐ray films showed that the acetabular cups were placed in anatomical position with 95% coverage of the acetabulum. Furthermore, initial stability of the femoral stem fixation was satisfactory and all osteotomies healed in 10–15 weeks. The Harris hip score had improved from 25–32 to 88–98 at one year after surgery (P < 0.01). All acetabular and femoral components were judged to be osteointegrated and well‐fixed during follow‐up. No components have needed revision. Conclusions: Subtrochanteric shortening osteotomy is a safe and predictable method for restoring the anatomic hip center in Crowe type IV ADH. The clinical outcomes of treating Crowe type IV ADH with THA were satisfactory.     

Surgical treatment of limb-length discrepancy following total hip arthroplasty

BACKGROUND: Although most patients with limb-length discrepancy following total hip arthroplasty have manageable symptoms, others may be disabled as a result of pain or functional impairment. In these patients, reoperation may be indicated to equalize the limb lengths. There is a paucity of published data regarding the outcome of surgical intervention to treat this problem. The purpose of the present study was to evaluate the results of revision hip surgery for the treatment of symptomatic limb-length discrepancy. METHODS: We retrospectively reviewed the clinical and radiographic records of patients who had undergone revision hip surgery at our institution for the treatment of a symptomatic limb-length discrepancy following a previous total hip arthroplasty. We identified twenty-one patients (twenty-one hips) who had an average age of sixty-six years at the time of revision hip arthroplasty. The average duration of follow-up was 2.8 years, and no patient was lost to follow-up. The indications for revision hip arthroplasty were severe hip and/or back pain for eleven patients, instability of the hip for eight, hip pain and ipsilateral limb paresthesia for one, and hip pain and ipsilateral foot drop for one. RESULTS: Revision arthroplasty was performed at a mean of eight months (range, six days to six years) after primary total hip replacement. The mean limb-length discrepancy at the time of the revision was 4 cm (range, 2 to 7 cm). Following revision arthroplasty, which involved revision of a malpositioned acetabular and/or femoral component, equalization of the limb lengths was achieved in fifteen patients. In the remaining six patients, the mean discrepancy had decreased to 1 cm. The mean Harris hip score improved significantly, from 56.5 points before the revision to 83.2 points at the time of the latest follow-up (p < 0.005). All but two patients were satisfied with the outcome of the revision surgery. CONCLUSIONS: Limb-length discrepancy following hip arthroplasty can be associated with pain, paresthesia, and hip instability. In these patients, careful evaluation of the position and orientation of the components may reveal the cause of the discrepancy. Revision arthroplasty may be indicated when a surgically correctable cause of limb-length discrepancy can be identified.     

Cementless total hip arthroplasty with a threaded acetabular cup

Summary. Eighty cementless total hip arthroplasties, using smooth threaded cups (Lord universal model), were carried out between 1985 and 1988. Sixty of these patients were available for clinical and radiological study with a mean follow up of 6 years. Five cups were revised for aseptic loosening and another 6 are awaiting revision, so 18% of the cups have failed. Fixation was classified as stable, fibrous-stable and unstable on radiographs. Twenty-six (43%) had fibrous-stable fixation and most were satisfactory clinically. This type of fixation must be carefully watched for signs of osteolysis, especially around the threads, as this precedes failure. Smooth threaded cups have good short term results, but deteriorate because of deficient osteointegration and later from wear debris. This type of cup does is not a good alternative to cemented cups.

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Résumé. Etude rétrospective de 80 arthroplasties totales par prothèse non cimentée utilisant une cupule vissée lisse (de type LORD) faite entre 1985 et 1988. 60 cupules vissées ont pu faire l’objet d’une étude clinique et radiologique avec une durée d’observation moyenne de 6 ans (4 à 10). 5 cupules ont été reprises pour un descellement aseptique et 6 autres doivent être révisées prochainement. Si l’on considère ces deux groupes, il y a donc 18% d’échec pour ces cupules. Une classification radiologique de la fixation de la cupule a été retenue en 3 types: fixation stable, fixation fibreuse stable et fixation instable. Seulement 23 hanches (38%) montraient radiologiquement une fixation stable de la cupule. 26 (43%) avaient une fixation fibreuse stable correspondant à un bon résultat clinique dans la majorité des cas. Ce type de fixation doit être observé attentivement en recherchant des signes discrets d’ostéolyse notamment le long du filtage, car c’est habituellement un stade précédant l’échec de fixation. D’après notre étude, nous pensons que les cupules lisses vissées permettent un bon résultat clinique et radiologique à court terme mais que la qualité de la fixation se détériore rapidement, probablement à la suite de défaut d’intégration puis comme résultat de la réaction aux débris d’usure. Au total, nous pensons que ce type de cupule ne constitue pas une bonne alternative aux cupules cimentées.

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Accepted: 26 November 1996     

Cementless acetabular reconstruction in revision total hip arthroplasty

Reconstruction of the failed acetabular component in total hip arthroplasty (THA) can be challenging. Although there are multiple reconstructive options available, a cementless acetabular component inserted with screws has been shown to have good intermediate-term results and is the reconstructive method of choice for the majority of acetabular revisions. We reviewed the results of 138 consecutive acetabular revisions done with a hemispheric, cementless acetabular component that is sintered with Ti fiber metal mesh and was inserted with line-to-line reaming and multiple screws for fixation. At a mean of 15 years, 19 acetabular components had been revised (13.8%); seven were revised for recurrent instability, six were revised for deep periprosthetic infection, five well-fixed cups were removed at the time of femoral revision, and one cup was fixed by fibrous tissue only at the time of femoral revision and was removed. One acetabular component was radiographically loose. Survivorship of the component was 81% at 15 years when revision for any reason was considered as an end point and 96% when revision for loosening or radiographic evidence of loosening was considered as a second end point. Cementless acetabular revision provides durable results at 15 years with a low rate of failure for loosening.     

Cementless dual-mobility cup in total hip arthroplasty revision

Purpose

Dislocation is a frequent complication in total hip arthroplasty (THA) revision. Cup fixation is the second concern. In order to know outcomes at two years, we prospectively followed a continuous series of 78 patients to demonstrate that cementless dual-mobility cup (DMC) used in revision THA is safe as regards dislocation risk and bone fixation.

Method

We enrolled 78 consecutive patients (79 cases) in a prospective study. Mean interval between index surgery and revision was 12.9 years. Mean age at revision was 75.5 years. Two types of cementless DMC were used: a standard DMC in 68 cases with low-grade bone defect (Paprosky grade 1 and 2), and a specific design reconstruction DMC in 11 cases with severe bone loss (Paprosky grade 3).

Results

At two years of follow-up, 68 patients were reviewed; four were lost to follow-up., and six patients were deceased. We identified three types of situations at risk:standard risk (33 cases), Paprosky grade 1 or 2; medium risk (37 cases), revision for recurrent instability (21), periprosthetic fractures (14) or severe loosening Paprosky grade 3 without femorotomy (2); high risk (nine cases), revision for severe loosening with a femorotomy. One (1.3 %) patient dislocated her hip at one month without recurrence. Revision rate for dislocation was 0 %; two (2.7 %) early mechanical failures occurred.

Conclusion

Considering outcomes of this series, cementless DMC can be suggested in THA revision surgery.