应用锥形沟槽式股骨组配柄假体行全髋关节翻修术的中期疗效

目的 探讨应用锥形沟槽设计的股骨组配柄假体行全髋关节股骨侧假体翻修术的中期疗效.方法 2000年5月至2005年8月采用锥形沟槽式股骨组配柄假体行全髋关节翻修术19例,男6例,女13例;年龄47～86岁,平均67岁.单髋17例,双髋2例.术前诊断均为股骨柄和臼杯假体无菌性松动合并股骨侧骨缺损,按Paprosky标准诊断为Ⅱ型缺损4髋,Ⅲa型缺损14髋,Ⅲb型缺损3髋.股骨侧翻修均采用锥形沟槽式股骨组配柄假体(Lima-Lto,意大利),髋臼侧均采用SPH臼杯假体(LimaLto,意大利)行生物学固定.关节头臼界面采用陶瓷-陶瓷组合17髋,金属-聚乙烯组合4髋.结果 全部病例随访5～10年,平均7年.Harris髋关节评分由术前平均(46.2±15.2)分改善至翻修术后半年平均(90.3±5.3)分,末次随访平均(92.2±3.5)分.X线片显示翻修柄获广泛骨长入骨性固定者20髋(95%,20/21),纤维性稳定者1髋(5%,1/21).假体下沉0～10 mm,平均2.4 mm.随访期间无一例因假体松动或其他原因需行再次翻修.结论 采用锥形沟槽式股骨组配柄假体行伴有PaproskyⅡ型、Ⅲa和Ⅲb型骨缺损的股骨侧假体翻修术,可获得理想的初始稳定和永久生物学固定,中期随访疗效满意.

Abstract：

Objective To evaluate the midterm results of the revision total hip replacement with a fluted and tapered modular stem. Methods Nineteen patients (21 hips) underwent revision total hip arthroplasty from May 2000 to August 2005 were reviewed. There were 13 females and 6 males, with an average age of 67 years. Pre-revision diagnosis included aseptic loosening of the cups and stems associated with femoral defects (Paprosky classification) type Ⅱ 4 hips (19%), type Ⅲa 14 hips (67%), and type Ⅲb 3 hips (14%). The adopted acetabular component was SPH (Lima-Lto, Italy), and femoral component was a fluted and tapered modular stem (Lima-Lto, Italy). Clinical and radiographic evaluations were performed postoperatively. Results The mean follow-up was 7 years (range, 5-10). The Harris hip score improved from 46.2±15.2 preoperatively to 90.3±5.3 postoperatively, and maintain 92.2±3.5 at the latest follow-up. The X-ray films showed bone ingrowths fixation in 20 hips (95%) and fibrous stable fixation in 1 hip (5%). The average stem subsidence was 2.4 mm (range, 0-10 mm). There were no re-revisions of the femoral stem for any reason. Conclusion The midterm results of revision total hip replacement with a fluted and tapered modular stem in Paprosky type Ⅱ, Ⅲ a, Ⅲ b femoral defect associated aseptic loosening of the femoral stem was encouraging.     

Uncemented bipolar double-cup arthroplasty of the hip in inflammatory arthropathy

From 1979 to 1986, 42 uncemented surface arthroplasties were performed in 27 patients with an inflammatory arthropathy of the hip: median age at operation 40 years (range 19-65 ys), median follow-up period 73 months (range 36-120 mo). After 36 months, in 26 of 42 hips, the mean Harris Hip Score was excellent or good (mean 89, range 80-100). In 14 cases, the mean score was fair (76, range 70-79). Overall, those hips with the longest followup period (60-120 m) gradually improved over the years. No correlation was found between the clinical score and radiologic complications such as varus tilting of the femoral component, acetabular protrusion of the cup, or heterotopic ossification. Conversion to a conventional total hip arthroplasty was required in four patients. One patient required a total hip arthroplasty 86 months after the initial operation because of a femoral neck fracture. In two other patients, revision was performed after 60 and 32 months respectively because of a preexistent osteonecrosis and a severe foreign body response to polyethylene debris. Both patients had a varus tilting of the femoral component. In the fourth patient, in whom revision surgery was necessary 28 months after surface replacement there was no explanation for the varus shift of the femoral component. Regarding those problems that can appear after conventional total hip replacement in inflammatory arthropathy, we conclude that the uncemented surface replacement of the hip can be a reasonable alternative.     

股骨髓腔狭窄患者生物柄全髋关节置换

背景：亚洲人体型较小,股骨通常较短且髓腔狭窄,进行人工髋关节置换时常会遇到插入困难,目前尚无有关股骨髓腔狭窄患者进行人工关节置换的相关报道。目的：探讨股骨髓腔狭窄患者生物柄假体全髋关节置换的固定特点与临床疗效。方法：2005年5月至2009年8月,采用锥形生物柄进行全髋关节置换22例23髋,男2例2髋,女20例21髋;年龄19～56岁,平均37.6岁。股骨髓腔峡部直径7.5～8.2mm,平均7.8mm。手术采用生物型全髋关节置换假体,其中三锥度生物型股骨直柄18例,二锥度生物型股骨直柄5例。术后第1、3、6个月及1年门诊随访,以后每年随访1次,随访时采用Harris髋关节评分评估髋关节功能,X线片观察假体压配和生物学固定效果。结果：全部病例随访28～72个月,平均38.5个月。1例22mm直径股骨头术后第3天侧卧拍片摆动体位时发生股骨头前脱位,经手法复位后回纳。Harris髋关节评分由术前（46.2±6.2）分改善至术后半年（90.2±5.1）分,末次随访仍维持在（92.1±3.2）分。23髋术后均立即实现股骨柄的压配。正侧位X线片示股骨柄的髓内充填分别达94%～98%,平均96.5%和87%～94%,平均91.2%。术后3个月的X线片示均获得广泛性骨长入。结论：股骨髓腔狭窄患者适当扩髓可获得良好的临床效果,周密而严谨的术前计划可准确地预测出假体型号、位置,并能有效缩短手术时间,减少术后并发症。     

The use of femoral struts and impacted cancellous bone allograft in patients with severe femoral bone loss who undergo revision total hip replacement: a three- to nine-year follow-up

We determined the midterm survival, incidence of peri-prosthetic fracture and the enhancement of the width of the femur when combining struts and impacted bone allografts in 24 patients (25 hips) with severe femoral bone loss who underwent revision hip surgery. The pre-operative diagnosis was aseptic loosening in 16 hips, second-stage reconstruction in seven, peri-prosthetic fracture in one and stem fracture in one hip. A total of 14 hips presented with an Endoklinik grade 4 defect and 11 hips a grade 3 defect. The mean pre-operative Merle D'Aubigné and Postel score was 5.5 points (1 to 8). The survivorship was 96% (95% confidence interval 72 to 98) at a mean of 54.5 months (36?to 109). The mean functional score was 17.3 points (16 to 18). One patient in which the strut did not completely bypass the femoral defect was further revised using a long cemented stem due to peri-prosthetic fracture at six months post-operatively. The mean subsidence of the stem was 1.6 mm (1 to 3). There was no evidence of osteolysis, resorption or radiolucencies during follow-up in any hip. Femoral width was enhanced by a mean of 41% (19% to 82%). A total of 24 hips had partial or complete bridging of the strut allografts. This combined biological method was associated with a favourable survivorship, a low incidence of peri-prosthetic fracture and enhancement of the width of the femur in revision total hip replacement in patients with severe proximal femoral bone loss.     

Long-term results of bulk femoral head autograft in cementless THA for developmental hip dysplasia

We evaluated the fate of bulk femoral head autograft in cementless total hip arthroplasty (THA) for developmental hip dysplasia. Of 87 hips (80 patients) studied, 37 hips (32 patients) were available for follow-up at a mean of 18.5 years (range, 15-24 years) postoperatively. The mean age of these 32 patients at the index procedure was 53.8 years (range, 40-65 years). The initial diagnosis was osteoarthritis in all 32 patients. The degree of acetabular dysplasia according to Crowe classification was type I in 18 hips (48.6%), type II in 14 (37.8%), type III in 5 (13.5%). The mean percentage of horizontal coverage of the acetabular components with graft bone was 34% (range, 25%-45%). Trabecular bridging across the graft-host interface was seen at a mean of 4 months (range, 2-6 months) postoperatively. Trabecular reorientation of the grafted bone was seen in all hips at a mean of 27 months (range, 12-36 months) postoperatively. There was no evidence of collapse and bony resorption of the grafted bone in the weight-bearing portion. Acetabular component fixation was stable in all hips at final follow-up. Of the 37 hips (32 patients), 2 acetabular components required revision: 1 for a late postoperative deep infection and 1 for dissociation of the polyethylene liner. The survival rate was 94.5% (95% confidence interval, 91.3-96.5) for the acetabular component at 18.5 years of follow-up. This study found that bulk femoral head autograft in cementless THA for developmental hip dysplasia produces excellent long-term results.     

Cone femoral prosthesis for osteoarthritis of the hip with femoral dysplasia

PURPOSE. To assess the clinical and radiological outcomes of total hip replacement (THR) using the cone femoral prosthesis. METHODS. Four men and 15 women (26 hips) aged 19 to 78 (mean, 45) years underwent THR for osteoarthritis of the hip with femoral dysplasia using the cone femoral prosthesis. Only 17 patients (24 hips) were available for review. Pain and functional limitation were assessed using the Oxford hip score. Stable fixation by bone ingrowth was defined as no subsidence or radiolucent lines around the prosthesis. RESULTS. The mean follow-up duration was 50 (range, 25-92) months. The mean Oxford hip score improved from 44 (range, 32-54) preoperatively to 17 (range, 12-28) at the latest follow-up. Prosthesis survival was 100%. All prostheses showed stable integration with bony ingrowth and no measurable subsidence. 15 hips had excessive anteversion of 25 to 90 degrees. No patient had venous thromboembolism, deep prosthetic infections or dislocations. CONCLUSION. The cone prosthesis is less complex and expensive than the modular prosthesis. The early functional and radiological outcomes were excellent, with marked improvement in pain and function. This constitutes effective treatment for osteoarthritis of the hip with femoral dysplasia.     

Clinical outcome and periprosthetic bone remodelling of an uncemented femoral component with taper design

We followed 48 consecutive patients (50 hips) with osteoarthritis who received a primary total hip replacement using a tapered stem with hydroxylapatite coating (Cerafit Multicone H-A.C.) and a press-fit cup. Mean follow-up was 3 years, mean patient age was 54.7 years, and mean preoperative Harris hip score was 57. Quantitative evaluation of periprosthetic bone remodelling was assessed 1 year after the index operation using computed tomography (CT). Clinical and radiological follow-up was obtained in all hips. The mean Harris hip score at follow-up was 96. Forty-nine hips were clinically rated good or excellent. No thigh pain was reported. Radiographs showed stable fixation by bone ingrowth in all hips. Fifteen hips were eligible for CT. Three years after operation, mean decrease of overall bone mineral density (BMD) was 14.2% and mean decrease of cortical BMD 15.5% in the metaphyseal portion. In the diaphyseal portion, mean decrease of overall BMD was 10.0% and mean decrease of cortical BMD 7.7%. Minimal changes were observed at the level of the tip of the stem. Clinical and radiological outcome using a tapered femoral stem with hydroxylapatite coating compares favourably with other reports. Osteodensitometry shows limited proximal femoral bone resorption.     

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.     

Horizontal platform supported hip replacement

The cementless horizontal platform supported femoral component for hip replacement was designed to provide physiologic stress loading of the proximal femur after hip replacement. The goal is to extend pain-free implant survival by reducing periprosthetic bone resorption and to provide improved hip function and many years of relief from hip pain. A total hip replacement using this prosthesis was done in 334 consecutive nonselective hips in 322 patients. The mean age of the patients at the time of total hip replacement was 69 years (range, 29-89 years). Thirty-two patients (34 hips) were lost to followup and 81 patients (83 hips) died less than 10 years postoperatively. The remaining 209 patients (217 hips) were followed up for a minimum of 10 years (maximum, 14 years). There were six revisions of the femoral prosthesis. Three (1.8%) were revised for loosening, two were revised for femoral fracture, and one was revised for unexplained pain. The rate of stem survival was 0.97 +/- 0.02 (mean and standard error). There were 209 (96%) hips with excellent or good results. Seven (3%) patients had osteolytic changes develop. Radiographic evidence of diminished bone density in the proximal femur was seen in 34 hips (16%). The clinical results are comparable with other reported results for cementless hip replacements at 10 years.     

Charnley low-frictional torque arthroplasty in young rheumatoid and juvenile rheumatoid arthritis: 292 hips followed for an average of 15 years

Introduction In the early 1960s, Charnley was cautious with his patient selection for total hip replacement. As follow-up increased and confidence in the operation grew, younger patients were selected. We present our results of the Charnley LFA in young patients with rheumatoid and juvenile rheumatoid arthritis with a followup of up to 36 years.

Patients We studied 292 Charnley low-friction arthroplasties in 195 young patients with an established diagnosis of rheumatoid arthritis. Their mean age at operation was 38 (12-50) years; 168 (58%) were receiving steroids and 79 (27%) were on non-steroidal antiinflammatory medication. The mean follow-up for the whole group was 15 (1-36) years. 24 patients could not be traced (33 hips), and 61 patients died (88 hips).

Results 25 patients (41 hips) had had a revision. The main indication for revision was cup loosening. In the 85 patients (130 hips) attending follow-up, their mean age at surgery was 36 (17-50) years and the mean follow-up was 20 (10-36) years. 98% were pain-free or had no more than occasional discomfort, 44% claimed to have normal or near-normal function, while 62% had full or almost full range of movement of the replaced hip. Radiographically, 29 cups (22%) were considered to be loose. 1 stem (1%) was definitely loose and 2 stems (2%) were probably loose. With revision for any indication as the endpoint, the survival was 74% at 25 years follow-up.

Interpretation The Charnley LFA continues to be an excellent hip replacement, even for very young rheumatoid arthritis patients. Wear and aseptic cup loosening are the main long-term problems.     

Total arthroplasty of the hip after childhood sepsis

Total hip arthroplasty was performed in 45 hips of 44 patients who had pyogenic arthritis of the hip during childhood. The average age of the patients was 36.4 years (range 19 to 50). The interval between active infection and arthroplasty ranged from 11 to 40 years, and average follow-up was 65.4 months (range 58 to 80). Specimens of tissue taken before and during operation gave negative cultures in all hips, and no patient had reactivation of infection. The mean functional rating of the hips was 58 points before operation and 90 at the final review. Complications were seen in 11 cases (24%), loosening of components occurred in six (13%) and one hip had to be revised for acetabular component migration. Acetabular allografts were required in 27 hips (60%). All allografts united but there was partial resorption of the graft in the non-weight-bearing area in all.     

无柄人工髋关节置换术的初步临床应用

目的 评价无柄人工髋关节置换术的早期随访结果,探讨其临床应用的安全性及可行性.方法 2002年2月至2007年3月,对51例56髋施行无柄人工髋关节置换术.男31例34髋,女20例22髋;年龄25～87岁,平均56.2岁.术前髋关节Harris评分平均(72.4±8.4)分.新鲜股骨颈骨折6例6髋,股骨颈骨折继发股骨头坏死4例4髋,股骨头缺血性坏死(FicatⅢ-Ⅳ期)34例37髋,强直性脊柱炎髋关节强直2例3髋,类风湿髋关节炎2例3髋,髋关节结核3例3髋.全髋关节置换50髋,半髋关节置换6髋.以Harris评分评价术后疗效,用Amstutz分区方法对X线片进行分区评价,观察假体位置及并发症情况.结果 全部病例随访2～7年,平均4.8年.髋关节Harris评分平均(92.8+3.2)分,其中优44髋、良7髋、可4髋、差1例,优良率91%.术后第2,3天发生关节脱位2例,经手法复位成功;术后40天发生感染1例,行关节腔病灶清除及持续关节腔冲洗后治愈;术后半年髋区疼痛1例,行有柄全髋关节翻修.随访期间X线片未见关节松动、脱位及螺钉松动、断裂等情况.结论 无柄人工髋关节置换术可保留股骨颈,创伤小、出血少易于于翻修,适合高龄体弱及年轻患者.早期疗效可靠,远期疗效有待进一步观察.     

生物型组配式锥形柄行全髋关节翻修术的中远期疗效

目的探讨应用生物型组配式锥形柄行全髋关节翻修术的中、远期疗效。 方法收集苏州大学附属第一医院2000年5月至2011年5月因假体无菌性松动、股骨侧骨缺损而采用生物型组配式锥形柄行全髋关节翻修手术的患者,排除肿瘤、假体感染及随访时间<5年的患者,共收录37例(39髋),其中采用利马股骨翻修柄19例(21髋),林克(LINK)MP翻修柄18例(18髋)。初次置换至翻修时间为4～15年,平均(10±4)年,均为首次翻修。股骨侧骨缺损分型按Paprosky标准：Ⅲa型28髋,Ⅲb型11髋。摩擦界面均使用陶瓷－陶瓷界面。Harris评分比较采用t检验,骨缺损程度分型组间差异采用卡方检验。 结果全部病例随访6～16年,其中11例随访6～10年,26例随访超过10年,平均(11.6±2.3)年。两种假体翻修时股骨缺损程度未见明显差异(χ²＝0.434; P>0.05)。术前平均Harris髋关节评分为(43±10)分,末次随访为(90±3)分(t＝32.334,P<0.05),两种翻修假体的临床疗效差异无统计学意义(t＝0.881,P>0.05)。X线随访显示翻修柄骨性稳定者38髋(97.4%),纤维稳定者1髋(2.6%)。假体平均下沉(2.1±2.3) mm(0～10 mm)。随访期间无1例因假体松动或其他原因需行再次翻修。 结论采用生物型组配式锥形柄假体行伴有Paprosky Ⅲa和Ⅲb型骨缺损的股骨侧假体翻修,可获得理想的初始稳定和永久生物学固定,中、远期随访疗效满意。     

Cementless total hip arthroplasty in patients older than 80 years of age

We reviewed 80 patients (87 hips) who were older than 80 years of age at the time of cementless total hip arthroplasty. An Alloclassic SL stem had been implanted in all patients. A variety of cementless acetabular components was used. After a mean follow-up of 69.3 months (39.2 to 94.1) 48 hips in 43 patients were analysed clinically and radiologically. One patient had sustained a traumatic periprosthetic fracture of the femur with subsequent exchange of the stem 73 months after operation. Thirty-two patients (34 hips) had died and five patients (five hips) were unavailable for follow-up because of health reasons (four patients) or lack of co-operation (one patient). If the endpoint is defined as removal of the prosthesis because of aseptic loosening, the survival rate was 100% for the cup and stem after 78 months. The mean Harris hip score was 81.9 points. Radiolucent lines and osteolysis were seldom found.     

Clinical experience with a proximally porous-coated second-generation cementless total hip prosthesis: minimum 5-year follow-up

This study reports the minimum 5-year follow-up of our experience with the Porous-Coated Anatomic E (PCA-E) series femoral stem and the modular acetabular cup. A total of 115 consecutive total hip replacements using PCA-E series (Howmedica, Rutherford, NJ) were performed in 108 patients. Six patients whose hips were performing well clinically died before 5-year follow-up and were excluded from the final evaluation. The remaining 109 hips (102 patients) were assessed at a mean follow-up of 72 months (range, 60-84 months). The hip diagnoses were osteoarthritis in 73, osteonecrosis in 31, rheumatoid arthritis in 2, and hip dysplasia in 3. The mean age was 56 years (range, 24-83 years). Three hips were revised: 1 because of late hematogenous infection, 1 because of aseptic loosening of the femoral component, and 1 because of postoperative loosening of an acetabular component. The Harris hip scores improved from a mean of 50 points (range, 20-66 points) preoperatively to a mean of 92 points (range, 64-100 points) at final follow-up. The score differed in each Charnley functional class, with a mean of 93 points (range, 72-100 points) in 57 hips of class A (no other joint involvement); 90 points (range, 58-100 points) in 26 hips of class B (opposite hip involvement); and 85 points (range, 37-100 points) in 26 hips of class C (multiple joint involvement or severe systemic disease). Out of 106 hips that had a full radiographic evaluation performed, 103 femoral components revealed stable bony ingrowth, 2 revealed stable fibrous ingrowth, and 1 showed migration with progressive loosening. This patient with radiographic loosening has minimal symptoms and has not required or been offered further surgery (Harris hip score of 86 points). The low aseptic loosening rate (2%) at minimum 5-year follow-up compares favorably with any cemented or cementless series. The osteolysis that was seen was focal and localized. The short follow-up does not allow determination of progression. There were no cases of distal osteolysis. We attribute the improved results from reported first-generation experience to multiple factors, including increased number of sizes (9 vs 6), increased proportional metaphyseal size, improved polyethylene manufacture (ram extruded vs machined), improved acetabular locking mechanism, and change to 26-mm from 32-mm femoral heads.     

Cementless total hip arthroplasty using the modular S-ROM prosthesis combined with corrective proximal femoral osteotomy

We present the results of total hip arthroplasty using S-ROM (Depuy, Warsaw, Ind) prosthesis combined with corrective femoral transverse osteotomy for hips with proximal femoral deformity. Fourteen hips were followed up for a mean of 61 months (range, 36-95 months), with a mean age at surgery of 55 years (range, 44-69 years). The average intraoperative blood loss was 638 mL, and the average operative time was 136 minutes. The average Harris Hip Score increased from 38.0 (range, 15.0-55.7) preoperatively to 82.0 (range, 34.6-92.7) at the latest follow-up. All the hips except for 1 acquired union of osteotomy and bone ingrowth. S-ROM modular stem, which gives sufficient rotational stability at both proximal and distal parts of the osteotomy, is useful for total hip arthroplasty combined with corrective femoral transverse osteotomy.     

Mittelmeier ceramic—ceramic prosthesis after 10 years

The clinical status of 83 Mittelmeier ceramic—ceramic (Mark II) cementless total hip prostheses (Autophor, Osteo AG, Selzach, Switzerland) implanted between 1978 and 1984 was analyzed. Retrieved tissue from the revised hips was studied histologically. The mean patient age was 47.5 years (range, 19–71 years). One or both components of 12 hips were revised (16% at 16 years in the survival study). Eleven acetabular components and seven stems were revised, with three of the sockets fractured. The mean follow-up period for the patients with unrevised hips was 12.3 years. Osseointegration was uncommon in both the cup and stem. Radiographic cup loosening was observed in 53% of hips at 16 years in the survival study, with most having a complete radiolucent line of 2 mm around the cup. Radiographic stem loosening appeared in 15% of hips at 16 years. Fibrous stable fixation was present in 64% of stems. Significant radiographic acetabular wear was not observed in any hip. The Mittelmeier Mark II prosthesis had worse long-term results than reported with cemented or other uncemented prostheses. Although there was no significant acetabular wear, intracellular ceramic wear debris was seen in the retrieved tissues.     

Risk factors affecting outcome of metal-on-metal surface arthroplasty of the hip

We evaluated radiologic and clinical features affecting the outcome of hybrid metal-on-metal surface arthroplasty of the hip in 119 hips in patients 40 years and younger. Only the hips that had either failed or had minimum 2-year followup were reviewed. Ninety-four hips in 83 patients with a mean age of 34.2 years (range, 15-40 years) were reviewed. Seventy-one percent of the patients were males and 29% of the patients were females; 14% had previous surgery. The Chandler index and surface arthroplasty risk index were calculated. The mean followup at 3 years (range, 2-5 years) showed that three hips were converted to a total hip replacement at a mean of 27 months (range, 2-50 months) after the original surgery, and 10 hips had significant radiologic changes. The mean surface arthroplasty risk index for these 13 problematic hips versus the remaining hips was significantly higher, 4.7 and 2.6, respectively. The mean angle between the prosthesis stem and femoral shaft in the problematic group was significantly smaller than in the remaining hips: 133 degrees and 139 degrees, respectively. With a surface arthroplasty risk index score greater than 3 the relative risk of early problems is 12 times greater than if surface arthroplasty risk index less than or equal to 3.     

Jumbo femoral head for the treatment of recurrent dislocation following total hip replacement

BACKGROUND: The purpose of this study was to assess the results of the use of a jumbo femoral head to restore stability in hips that had sustained recurrent dislocations after total hip replacement. METHODS: Twelve hips in twelve patients who had had multiple hip operations and recurrent instability of the hip underwent a total hip replacement with use of a femoral head with an average diameter of 44 mm (range, 40 to 50 mm). The average age of the patients was fifty-nine years (range, twenty-nine to eighty-four years). The twelve patients had had an average of four previous operations (range, one to eight operations) and seven dislocations (range, two to twenty dislocations). A bipolar head was used in ten hips that had a femoral stem with a fixed (non-modular) head, and a modular head (unipolar) was used in two hips. (One hip was first treated with a bipolar head and then with a unipolar head.) RESULTS: One patient died of unrelated causes fourteen months postoperatively. The hip had remained stable until the time of death. After an average duration of follow-up of 6.5 years (range, 3.2 to 11.8 years), ten of the remaining eleven hips had had no additional episodes of instability. One hip dislocated within one week after the revision, necessitating revision surgery to reposition the acetabular component. This hip was found to be stable at the time of follow-up 7.6 years after the revision. There were four other reoperations: one was done because of a fracture of the polyethylene; one, because of entrapment of cement within the articulation; one, because of pain related to loosening of the femoral stem; and one, because of late hematogenous infection. The preoperative and postoperative University of California at Los Angeles hip scores for the series were, respectively, 7 and 9 points for pain, 5 and 7 points for walking, 4 and 6 points for function, and 3 and 5 points for activity. CONCLUSIONS: A jumbo-diameter femoral head provided stability and improved function without compromising range of motion in patients with recurrent dislocations following total hip arthroplasty.     

Zweymueller with metal-on-metal articulation: clinical,radiological and histological analysis of short-term results

BACKGROUND: This is a prospective study. METHOD:. A total of 266 consecutive patients, who received 350 third-generation Zweymueller-SL total hip arthroplasties with metal-on-metal articulation for primary or secondary osteoarthritis, was followed and evaluated clinically, radiologically and histologically. The age of the patients at the time of surgery was 55+/-9 years, (range 25-70 years). Seven ( 3%) patients did not return for their last follow-up evaluation for reasons unrelated to their hip operation. RESULTS: The mean follow-up was 52 months (range 37-92 months). The preoperative Harris hip score was 45+/-19 and increased to 96+/-4 postoperatively. The invalidity of the patients was significantly improved postoperatively ( p<0.001). In all, 97% of the patients were satisfied or very satisfied with the result of the operation. There was no aseptic loosening noted in this series. Revision was done in 6 (1.8%) hips because of septic loosening ( n=5, 1.5%) or technical error ( n=1, 0.3%) during implantation. Dislocation of the prosthesis occurred in the early postoperative period in 2 (0.6%) hips. Periarticular ossification was observed in 30% of the hips (5% Brooker grades III and IV), but without associated disability. During revision surgery, no macroscopic metalosis could be identified in the newly formed hip joint membrane; however microscopic evidence for metalosis (Mirra grades 1 and 2) was seen in all revised hips. The survival for Zweymueller screw socket and stem 7.6 years after implantation was 99.4% and 96.8%, respectively. CONCLUSIONS: This study showed that the short-term results of Zweymueller total hip arthroplasty with metal-on-metal articulation were just as satisfactory as those of a conventional polyethylene on ceramic articulation, while the metal-on-metal articulation does not seem to give rise to new problems or complications.