Polyethylene wear in prosthetic hips with loose components

We measured in vivo polyethylene wear of acetabular cups in 74 patients (83 hips) with Charnley total hip arthroplasties (THA), revised because of aseptic loosening of either the acetabular or femoral component. We analyzed conventional pelvic radiographs of 42 THAs before revision due to loose acetabular components alone and 41 THAs before revision due to loose femoral components alone. The THAs were revised after 10 to 26 years. The mean wear-rate in hips with a loose acetabular components was 0.3 mm/y, whereas in hips with a loose femoral components, it was 0.1 mm/y (P=.0001). The mean total linear wear, as measured on the last available radiographs before revision, was 3.4 mm and 1.5 mm, respectively (P=.0001). A significant difference in linear wear between hips with loose cups and loose stems was seen 1 year after surgery: 0.4 mm/y versus 0.3 mm/y, respectively (P=.05).     

Hybrid total hip arthroplasty in patients under the age of fifty: A five- to ten-year follow-up

In 37 patients, 45 total hip replacements were performed using contemporary cementing techniques, an uncemented Harris-Galante I acetabular component and a cemented precoated Iowa femoral component in patients under the age of 50 at the time of their surgery; 36 patients with 43 hybrid hips were living, 1 patient with 2 hybrid hips was decreased. No patients were lost to follow-up. At 5- to 10-year follow-up, eight hips were revised for aseptic loosening. No acetabular components, and eight femoral components (18%) were revised for aseptic loosening. When looking at radiographic results, including revision as well as those components that were probably or definitely loose on radiographs, 0 acetabular components and 11 femoral components (24%) were radiographically loose. These results demonstrate the excellent durability of the uncemented Harris-Galante acetabular component in the younger patient. However, the Iowa grit-blasted methyl methacrylate precoated femoral component had a magnitude increase in the prevalence of revision for aseptic femoral loosening when compared to the senior author's long-term Charnley results in this age group. The authors attribute the failure to the rough surface finish applied to the femoral component. However, the polymethyl methacrylate proximal precoating and the femoral component design may also contribute to the femoral failures.     

Revision total hip arthroplasty in juvenile chronic arthritis: 17 revisions in 11 patients followed for 4-12 years

BACKGROUND: Revision total hip arthroplasty (THA) in patients with juvenile chronic arthritis (JCA) is complicated by the young age of the patient, poor bone stock and small physical proportions. We report the complications and outcome of a prospective series of 17 revision THAs in Charnley class C JCA patients. METHODS: 15 acetabular components and 10 femoral components were revised. 13 cementless cups, 2 reconstruction/roof rings and cemented cups, and 4 cemented and 6 cementless femoral stems were implanted. 2 proximal femoral allografts and 1 strut allograft were used. Age at revision was 32 (21-53) years. Follow-up averaged 7 (4-12) years. RESULTS: 2 patients with cemented femoral stems developed loosening, osteolysis and fracture. Both were successfully revised to long-stem cementless implants with strut/proximal femoral allografts. 1 loose, worn cementless cup with osteolysis was revised. 1 patient with a peri-operative infection and late acetabular fracture had a loose, non-revised cementless cup. 1 case of sciatic nerve palsy occurred after revision using a reconstruction ring. 1 late infection necessitated resection arthroplasty. Harris hip scores improved from 53 (34-85) to 76 (47-96). INTERPRETATION: Revision THA in JCA has a substantial complication rate, even in experienced hands. The problem of obtaining long-term stable fixation, osteolysis, and replenishment of lost bone stock are major difficulties.     

Revision total hip arthroplasty in juvenile chronic arthritis: 17 revisions in 11 patients followed for 4–12 years

Background Revision total hip arthroplasty (THA) in patients with juvenile chronic arthritis (JCA) is complicated by the young age of the patient, poor bone stock and small physical proportions. We report the complications and outcome of a prospective series of 17 revision THAs in Charnley class C JCA patients.

Methods 15 acetabular components and 10 femoral components were revised. 13 cementless cups, 2 reconstruction/roof rings and cemented cups, and 4 cemented and 6 cementless femoral stems were implanted. 2 proximal femoral allografts and 1 strut allograft were used. Age at revision was 32 (21–53) years. Follow-up averaged 7 (4–12) years.

Results 2 patients with cemented femoral stems developed loosening, osteolysis and fracture. Both were successfully revised to long-stem cementless implants with strut/proximal femoral allografts. 1 loose, worn cementless cup with osteolysis was revised. 1 patient with a peri-operative infection and late acetabular fracture had a loose, non-revised cementless cup. 1 case of sciatic nerve palsy occurred after revision using a reconstruction ring. 1 late infection necessitated resection arthroplasty. Harris hip scores improved from 53 (34–85) to 76 (47–96).

Interpretation Revision THA in JCA has a substantial complication rate, even in experienced hands. The problem of obtaining long-term stable fixation, osteolysis, and replenishment of lost bone stock are major difficulties.     

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.     

Primary hybrid total hip replacement, performed with insertion of the acetabular component without cement and a precoat femoral component with cement. An average ten-year follow-up study

One hundred and twenty-one primary hybrid total hip replacements were performed in 107 patients. A titanium, porous-coated, hemispherical acetabular component was fixed with screws, and a collared, chromium-cobalt femoral stem, with a roughened surface and a thin layer of methylmethacrylate on the proximal third, was inserted with contemporary cementing techniques (that is, use of a femoral medullary plug, a cement gun, and centrifugation and pressurization of the cement). Fifteen patients (fifteen hips) died before a minimum duration of follow-up of seven years, four patients (four hips) were too ill for a detailed follow-up examination at the time of the study, and two patients (two hips) refused to be evaluated at the time of the latest follow-up. None of these twenty-one hips had had a revision or a reoperation at the time of the latest follow-up. Eighty-six patients (100 hips) were available for clinical follow-up at an average of 120 months (range, eighty-four to 153 months) and for radiographic follow-up at an average of 118 months (range, eighty-four to 153 months). The average age of the patients at the time of the index arthroplasty was sixty-five years (range, forty-five to eighty-seven years). Three acetabular components were revised because of dissociation of the liner in association with a fracture of a locking tine. One well fixed acetabular component was revised because of pelvic osteolysis, and the femoral stem in the same patient was revised because of aseptic loosening. None of the ninety-six remaining acetabular components migrated, was classified as radiographically loose, or was revised because of aseptic loosening. Osteolytic lesions were identified adjacent to five acetabular components, and one of them was treated with bone-grafting around the well fixed acetabular shell. Two hips had a continuous radiolucent line at the interface between the acetabular implant and the bone. Three femoral stems had evidence of radiographic debonding (a radiolucent line that was one millimeter wide or less between the cement and the prosthesis), and they were classified as radiographically loose despite excellent clinical results. Seven hips had osteolytic areas located in the proximal aspect of the most proximal zones of Gruen et al., and five had small osteolytic regions in more distal areas. The Harris hip score for the eighty-two patients (ninety-six hips) who did not have a revision improved from 48 points (range, 22 to 70 points) preoperatively to 92 points (range, 53 to 100 points) at the most recent follow-up examination. Eighty-one patients had no, slight, or mild pain in the hip, and they were satisfied with the clinical result. In the present study, the hybrid total hip replacement with use of the Harris-Galante acetabular component and the Precoat femoral stem continued to provide an excellent result for most patients at an average of approximately ten years after the operation.     

A preliminary report of the use of a cementless acetabular component with a cemented femoral component

A clinical and roentgenographic study was done on 52 primary total hip arthroplasties (THAs) in which all patients were treated with hip reconstruction with a combination of a cementless, porous-coated acetabular component and a cemented femoral component. The operations were performed between November 1982 and May 1984, and the patients were followed for an average of 31 months (range, 24-40 months). The average age of the patients (55 years) was younger than in many THA series. At the last follow-up assessment, 50 hips were classified as good or excellent, one as fair, and one as a poor result. No total hip component required revision. No acetabular components had migrated as judged by conventional roentgenographic examination, and only one hip had progressive radiolucencies around the acetabular component. No femoral component was rated definitely loose or probably loose, and only one was rated possibly loose. If long-term follow-up study confirms these preliminary results, the combination of a cemented femoral component with a cementless socket may prove to be of value for selected patients requiring THA.     

Excellent long-term results of the Müller acetabular reinforcement ring in primary total hip arthroplasty

Background and purpose — The original Müller acetabular reinforcement ring (ARR) shows favorable medium-term results for acetabular reconstruction in total hip arthroplasty, where it is used when the acetabular bone stock is deficient. However, there are no data regarding long-term survival of the device. We therefore investigated long-term survival and analyzed radiological modes of failure.

Patients and methods — Between 1984 and 2002, 321 consecutive primary arthroplasties using an ARR were performed in 291 patients. The mean follow-up time was 11 (0–25) years, and 24 hips were lost to follow-up. For survival analysis, we investigated 321 hips and the end of the follow-up was the date of revision, date of death, or the last patient contact date with implant still in situ. Radiological assessment was performed for 160 hips with a minimum of 10 years of follow-up and with radiographs of sufficient quality. It included evaluation of osteolysis, migration, and loosening.

Results — 12 ARR THAs were revised: 1 isolated ARR revision for aseptic loosening, 4 revisions of the ARR and the stem for aseptic loosening, 6 for infection, and 1 for recurrent dislocation. The cumulative revision rate for all components, for any reason, at 20 years was 15% (95% CI: 10–22), while for the ARR only it was 7% (95% CI: 4–12) for any reason and 3.4% (95% CI: 1–9) for aseptic loosening. 21 (13%) of 160 ARR THAs examined had radiological changes: 7 had osteolysis but were not loose, and 14 were radiologically loose but were not painful and not revised.

Interpretation — Our data suggest that the long-term survival of the ARR is excellent.     

A long-term follow-up study of the cementless THA with anatomic stem/HGPII cup with 22-mm head

The anatomic femoral component and Harris-Galante porous II (HGPII) cup were developed to provide more reliable bone ingrowth. We performed 20 cementless total hip arthroplasties (THAs) with anatomic stem/HGPII cup with 22-mm head in 14 consecutive patients, and evaluated the clinical and radiological results for a mean follow-up of 12.8 years. The all-anatomically designed stem provided excellent clinical and radiographic results. Four acetabular components underwent revision: three for fracture of the locking mechanism and wear of the polyethylene liner and one for the locking mechanism failure with dislocation of the HGPII cup. The abduction angles of the four revised acetabular components were apparently higher. The survivorship 13 years after surgery was 78%. Our findings show good long-term results using the anatomic femoral component, while the HGPII cup combined with 22-mm head seems to have poor durability due to locking mechanism failure.     

20-year experience with cemented primary and conversion total hip arthroplasty using so-called second-generation cementing techniques in patients aged 50 years or younger

We present the 20-year experience of 47 hips in 40 patients aged 50 years or younger with cemented primary total hip arthroplasty using second-generation femoral cementing techniques. Average follow-up duration in the 23 patients living at least 17 years was 18.2 years. Overall, 18 hips (38%) had components revised or removed for any reason, at an average duration of 12.6 years. Every revision or reoperation involved removing the acetabular component. Of these 18 acetabular components, 15 (32%) were revised for aseptic loosening. Eleven additional acetabular components were loose by radiographic criteria at final follow-up, yielding prevalence of aseptic acetabular loosening (55%). Four femoral components (8%) were revised for osteolysis without loosening, and 3 (6%) were revised for aseptic loosening. Femoral osteolysis, with or without component loosening, led to revision in 5 ( 11%) hips compared with 6% for aseptic loosening alone. Osteolysis was the primary problem leading to acetabular and femoral component revision in this series of people < or = 50 years old over the first 20 years after the index operation.     

Hybrid total hip arthroplasty

One hundred twenty-six primary total hip arthroplasties composed of a hybrid cemented femoral component and a cementless acetabular component were followed for a minimum of two years (mean, 42 months). The average patient age was 63 years. The most common diagnosis was osteoarthritis (85 hips), although 13 of the cases were severe or total congenital dislocations. Overall, the results were excellent. The mean Harris hip score was 93. Postoperative pain was rated as none or slight in 94% of the cases. No patient had moderate or severe pain. No femoral or acetabular components were revised. Roentgenographically no femoral component was definitely or probably loose. One acetabular reconstruction component had migrated. The authors conclude that the selective use of cemented and cementless fixation by anatomic site in this hybrid form of hip arthroplasty provided excellent results for five and one-half years.     

Acetabular revision after failed total hip arthroplasty in patients with congenital hip dislocation and dysplasia. Results after a mean of 8.6 years

BACKGROUND: Revision of a total hip arthroplasty in a patient who has had congenital hip dysplasia or dislocation is often more difficult than a standard revision operation. The purpose of this study was to assess the efficacy and complications of use of a cementless hemispherical acetabular component for revision of an acetabular component of a failed total hip replacement in patients whose initial problem was arthritis secondary to congenital dislocation or dysplasia. The mean duration of follow-up was approximately eight years. METHODS: We reviewed a consecutive series of sixty-one hips in fifty-three patients who underwent a cementless acetabular revision with use of a hemispherical acetabular component, with or without concurrent femoral revision. Data were collected prospectively. The mean age of the patients at the time of the index operation was fifty-six years. A mean of 1.9 ipsilateral hip operations had been performed previously. Thirty-nine hips (64 percent) had a so-called high hip center prior to the index revision. With one exception, the uncemented acetabular component was fixed with screws. Fifty-one acetabular components were placed with so-called line-to-line fit, and ten were oversized by one to three millimeters. In thirty-eight hips, the femoral component was revised as well. Twenty-nine femora were reconstructed with use of a cemented device, and nine were revised with an uncemented patch-porous-coated femoral stem (a stem on which the porous coating appears in patches). RESULTS: Four patients (five hips) died prior to the five-year minimum follow-up interval. With the exception of one hip treated with resection arthroplasty because of deep infection, none of the hips in these deceased patients had been revised or had a loose component. One living patient (one hip) had a resection arthroplasty, and one additional patient (two hips) had both stable acetabular components rerevised at the time of femoral rerevision at another institution because of loosening and osteolysis. One patient refused to return for follow-up, but the components had not been revised. The remaining fifty-two hips in forty-six patients were followed for a mean of 8.6 years (range, 5.0 to 12.7 years). The mean Harris hip score was 80 points (range, 56 to 100 points) at the time of the latest follow-up. No acetabular component had been revised, although two had migrated. No other acetabular component was loose according to our radiographic criteria. Thus, the mechanical failure rate on the acetabular side was 3 percent (two of sixty-one) for the entire series and 4 percent (two of fifty-two) for the patients who had been followed for a mean of 8.6 years. On the femoral side, the mechanical failure rate was 3 percent (one of twenty-nine) for the cemented stems and six of nine for the uncemented patch-porous-coated stems. CONCLUSIONS: Of the approaches used in this difficult series of patients requiring revision, the hybrid arthroplasty (a cementless acetabular component and a cemented femoral component) yielded overall good results after an intermediate duration of follow-up.     

Efficacy of alumina ceramic heads for cemented total hip arthroplasty.

Fifty-seven cemented total hip arthroplasties (THAs) were reviewed in cases of osteoarthrosis secondary to congenital dysplasia or dislocation. The bearing surface of the prosthesis used in this series consists of a polyethylene acetabular component on an alumina ceramic head. All acetabular components were positioned at the same level as the original acetabulum, and an autologous femoral head graft was performed for 18 hips. The follow-up period ranged from five to eight years, averaging six years two months. The latest survey showed excellent and good results for 53 hips (92.9%). Four acetabular components (7%) and two femoral components (3.5%) showed roentgenographic evidence of loosening. Only one hip (1.8%) had to be treated with revision surgery for femoral component loosening. None of the cases suffered a broken ceramic head. The use of a total hip prosthesis with an alumina ceramic head in THA is likely to lead to excellent results for patients with osteoarthrosis of the hip.     

Results of isolated acetabular revisions: The fate of the unrevised femoral component

Controversy exists over whether to remove a well-fixed femoral component at the time of revision of a failed acetabular component, and it has been suggested that the femoral component be removed and recemented. The hypothesis presented in this article is that only the acetabular component should be revised in these situations. Thirty-eight isolated, uncemented acetabular revisions were performed by 1 surgeon and prospectively followed for a mean of 4 years (range, 2–10 years). The femoral component was well fixed at the time of revision and left in situ. There were 30 cemented and 8 uncemented femoral components, which had been in place for a mean of 10.7 years. The hips were evaluated clinically using the Harris hip score rating system. Radiographic evaluation of both components was performed using well-established criteria. Morselized cancellous allograft was used to fill acetabular defects in 30 hips, and a bulk allograft was used in 1 hip. There was a good or excellent clinical result in 32 hips (84%). Two cemented femoral components required revision for aseptic loosening at 2.5 and 4 years. No acetabular component migrated or was revised, and no revisions of either component are pending. Thirty-six (95%) of the unrevised femoral components remain well fixed at the most recent follow-up examination. Compared with a similar population of hips in which both the acetabular and femoral components were revised, the mean blood loss for these revisions was 52% less and the mean surgical time was 35% shorter. Revision of only the acetabular component is recommended for isolated acetabular aseptic loosening. Because the femoral component is not removed, surgical time and blood loss are decreased and serious potential complications related to removing a well-fixed femoral component can be avoided.     

Primary total hip arthroplasty with the Karl Zweymüller first-generation cementless prosthesis: A 5- to 9-year retrospective study

A consecutive series of 72 primary total hip arthroplasties were performed in 70 patients using the first-generation Zweymüller cementless titanium press-fit femoral and threaded acetabular components (AlloPro, Baar, Switzerland). Twelve hips were excluded from the study because of insufficient follow-up evaluation, including one patient who underwent a socket revision within the first 2 weeks. Sixty total hip arthroplasties with an average follow-up period of 80 months (range, 60–108 months) were retrospectively reviewed. Clinical results were graded excellent or good in 54 cases (90%), fair in 3 (5%), and poor in 3 (5%) with 2 early implant failures (1 acetabular cup and 1 femoral stem in 2 hips). Cumulative survival rates at the 6- to 7-year interval, with failure defined as revision and/or loosening are 98.47% (SD, 2.0%) for the femoral component (1 single septic and loose stem, revised at 5 years), 97.08% (SD, 2.72%) for the screw ring (2 unstable but only 1 revised), and 95.56% (SD, 3.36%) for both components. This encouraging experience with the first-generation prosthesis supports the rationale for continued use of the new Zweymüller Alloclassic stem and open-back screw ring available since 1988.     

Intermediate- to Long-Term Results After Hybrid Total Hip Arthroplasty in Patients With Rheumatoid Arthritis

There have been few reports describing intermediate- to long-term results after hybrid total hip arthroplasty in patients with rheumatoid arthritis. We followed up 52 hips in 44 patients aged 5 men and 39 women, with a mean of 11.5 years (range, 5-23.5 years). Revisions had been performed in 6 hips in 6 patients: 1 both acetabular and femoral components for infection, 1 acetabular component for aseptic loosening, 3 acetabular components for recurrent dislocation, and 1 acetabular component for dislodgement of the polyethylene liner from the metal shell. None of other acetabular or femoral components were revised or found to be loose at the final follow-up. Although postoperative dislocation remains a concern, hybrid total hip arthroplasty had an acceptable result in patients with rheumatoid arthritis.     

The fate of stable femoral components retained during isolated acetabular revision: a six-to-twelve-year follow-up study

BACKGROUND: The decision as to whether to revise a well-fixed femoral component in hips requiring isolated acetabular revision is challenging. The purpose of the present study was to determine the long-term results of, and the complications associated with, retention of a stable and well-fixed femoral component during isolated acetabular revision. METHODS: We retrospectively reviewed the clinical and radiographic results for thirty-one patients (thirty-two hips) who underwent isolated revision acetabuloplasty without removal of a well-fixed femoral component. The reason for acetabular revision was aseptic loosening in thirty-one hips and malposition in one hip. Of the thirty-two femoral components, twenty-one were cemented and eleven were cementless. The average duration of follow-up from the time of the index revision was 8.1 years (range, 6.4 to 12.5 years), and the average duration of total service of the femoral component was seventeen years (range, seven to twenty-five years) from time of the initial implantation. The average age of the patients at the time of the index revision was sixty-six years (range, twenty-nine to eighty-seven years). RESULTS: Thirty-one (97%) of the primary femoral components were judged to be stable and well fixed at the latest follow-up evaluation. One femoral component (3%) was revised because of aseptic loosening, eight years after the index acetabular revision and seventeen years after the initial total hip arthroplasty. Radiographic evaluation of the thirty-one femoral components that were not revised demonstrated no evidence of loosening or subsidence. There were no dislocations, nerve palsies, or intraoperative fractures associated with retention of the femoral component. Twenty-seven (84%) of the acetabular components were judged to be stable at the latest follow-up evaluation. CONCLUSION: In hips treated with isolated acetabular revision, a well-fixed femoral component can be retained successfully without adversely affecting the acetabular exposure; the placement, position, or stability of the acetabular component; or the ability to restore bone stock. The data from the present study support the decision to retain a well-fixed femoral component when the acetabular component needs to be revised.     

Threaded acetabular components for primary and revision total hip arthroplasty

A clinical and radiographic review of 48 total hip arthroplasty patients with threaded acetabular components was undertaken at 24-44 months of follow-up study. Twenty-five patients had primary hip arthroplasties and 23 had revision procedures. Clinical scores revealed good to excellent results in 60% of primary and 30% of revision procedures. Radiographic analysis revealed stable acetabular components in 88% of primary and 61% of revision procedures. Potentially loose acetabular components were noted in 8% of primary and 4.3% of revision procedures and loose acetabular components in 4% of primary and 34.7% of revision procedures. The rate of acetabular component loosening was considered unacceptably high in revision cases and an area of concern in primary cases. Discretionary use of these components is advised.     

Tapered titanium cementless total hip replacements: a 10- to 13-year followup study.

The 10- to-13 year performance of 307 Mallory Head cementless tapered total hip replacements in 283 patients was assessed. Eighty-five percent of patients had a diagnosis of osteoarthritis. Fifty-one percent of patients were women. The mean patient age was 64 +/- 10 years. The Hex Loc cementless acetabular component and titanium alloy femoral heads were used in each patient. At final followup, 37 (13%) patients died, 32 (10%) had revision surgery, and two (1%) were lost to followup. No femoral stem was revised for aseptic loosening, but one was revised because of sepsis and one was revised because of a periprosthetic fracture. Wear, osteolysis, and loosening were problems with the Hex Loc cementless acetabular components and 31 (10%) acetabular components required revision because of these mechanisms. The mean Harris hip score at final followup of the remaining patients was 87 +/- 14 points. Three percent of these patients had thigh pain. Radiographic assessment revealed that no femoral stem or acetabular socket was definitely or probably loose. Three-dimensional wear assessment using the Devane technique was 0.35 mm per year. The Mallory Head cementless, tapered femoral component performed well in the patients in the current study, but unfortunately, the clinical results were compromised by the use of a suboptimal cementless acetabular component, the use of polyethylene that was gamma-irradiated in air, and by the use of titanium alloy femoral heads. Future developments obviously will be in the areas of better acetabular component design, alternate polyethylene sterilization methods, and enhancements of the femoral stem in terms of offset choices, neck design, and perhaps ingrowth surface.     

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。