Clinical outcome and quantitative evaluation of periprosthetic bone-remodeling of an uncemented femoral component with taper design. A prospective study

The rationale of uncemented taper stems is based on fixation in the proximal portion of the femoral diaphysis, a self-locking principle, and a low modulus of elasticity. The aim of this study was to evaluate a collarless femoral component designed to be a three-dimensional taper for press-fit insertion with regard to clinical outcome, efficacy of fixation, incidence of osteolysis, and periprosthetic bone-remodeling. The first 48 consecutive patients (50 hips) with osteoarthritis who had had primary total hip arthroplasty using the Cerafit Multicone stem and the Cerafit Triradius-M press-fit cup with alumina-alumina pairing (Ceraver Osteal, Paris, France) were followed-up for a mean of 2.3 years (2 to 2.5 years). The mean age of patients at index operations was 52.5 years. Current criteria were used for clinical and radiological assessment. Quantitative evaluation of periprosthetic bone-remodeling was prospectively assessed using computed tomography. Clinical and radiological follow-up was obtained in all hips. Forty-nine hips (98%) were clinically rated good or excellent, one hip (2%) was rated fair, owing to a persisting limp. The mean preoperative Harris Hip Score was rated 62, and it has improved to 93.5 at the time of follow-up. One hip (2%) had marked postoperative thigh pain. This pain had disappeared at 3-month follow-up. All stems showed radiological signs of stable fixation by bone ingrowth. No stem required revision. Thirty-four hips (68%) had either no change in femoral bone density or only patchy loss of bone density isolated to Gruen zones 1 and 7. Sixteen hips (32%) had some reduction of bone density isolated to zone 1. Radiolucencies without progression were found in zones 1 and 7 in 3 hips (6%), and in zone 1 alone in 3 other hips (6%). A slight cortical hypertrophy was seen in 3 hips (6%). Twenty-three hips (46%) developed radiographic appearance of bone apposition at the stem tip as partial pedestal (19 hips) and as complete pedestal (4 hips). No signs of cup loosening were detected at follow-up. Twenty-four patients (25 hips) were eligible for computed tomography. The mean decrease of the overall bone mineral density in the metaphyseal portion of the femur one year after insertion of the stem was rated 15.4%, and the mean decrease of the cortical bone mineral density was rated 17.2%. On the other hand, a mean decrease of the cortical bone mineral density of less than 5% was observed in the diaphyseal portion of the femur around the implant. The clinical and radiological results of the Cerafit Multicone stem at a mean follow-up of 2.3 years are very promising and do not contrast with those achieved using other uncemented stems with tapered design. Furthermore, results of quantitative evaluation of periprosthetic bone-remodeling were considered satisfactory favourably with others reported in the literature using stems inserted without cemented.     

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.     

Revision total hip arthroplasty using a fluted and tapered modular distal fixation stem with and without extended trochanteric osteotomy

We reviewed 62 revision total hip arthroplasties performed using a fluted and tapered modular distal fixation stem after a mean follow-up of 4.2 years. An extended trochanteric osteotomy (ETO) was used in 32 of the 62 hips (52%), whereas no osteotomy was used in the remaining 30 hips. The mean postoperative Harris hip score among the patients was 87.3 points. The mean stem subsidence was 1.1 mm. With the exception of one reoperation for a deep infection, no femoral revision was performed because of mechanical failure. Complications included intraoperative diaphyseal split fractures (6%), cortical perforations (6%), and dislocations (5%). Postoperative Harris hip scores, femoral component stability, and overall complication rates did not differ between the group treated with an ETO and that treated without it. However, the rates of cortical perforation and marked stem subsidence (>5 mm) were significantly higher in the group treated without an ETO than those in the group treated with an ETO, but these were not significantly different when stratified by femoral bone defect. The potential advantages of this implant design could be highlighted in a clinical setting when inserted using an ETO.     

Total hip arthroplasty using an uncemented femoral component with taper design: outcome at 10-year follow-up

The aim of this study was to assess the clinical and radiological outcome of the cementless-system (CLS) femoral component designed by Spotorno with a taper design. Ninety-four patients (107 hips) were operated on from January 1987 to December 1988. The female/male ratio was 2/1, the mean age was 51 years (range 20–77 years). Clinical follow-up was obtained in 89 hips (83%). Five patients (7 hips, 6.5%) could not be traced. Nine patients (11 hips, 10%) had died before the minimum time of follow-up required for this study (10 years). All these hips still had their stem in place at the time of the last intermediate inquiry. The mean follow-up was 10.3 ± 0.3 years. No stem required revision. According to the Harris score, 84% of hips were rated good or excellent, 14% fair, and 2% poor. The average Harris hip score was 88 at the time of the last follow-up. Fifteen patients (17%) reported occasional thigh pain. All patients reported complete relief of pain within the first 6 months after the operation. Radiologically, 95% of stems showed stable fixation by bony ingrowth, 5% by fibrous ingrowth. Seven (9%) uncemented acetabular components showed progressive migration. Three of those cups had been replaced in the meantime. Fifty-one (65%) of the CLS stems induced either no change in femoral bone density or only patchy loss of bone density localized to zone 1 or 7 according to Gruen, while 27 (35%) of the hips showed some reduction of bone density in the proximal diaphysis of the femur (zone 2 or 6). Severe progressive osteolysis of the femoral cortex underneath the lesser trochanter was found in 4 hips (5%) with coexistent loosening of the cup. In all of these hips, the Mecron cup had been used. At a mean follow-up of 10 years, the results of the CLS femoral component are comparable with those of modern techniques of cementing in primary total hip arthroplasty and with the long-term outcomes of other uncemented stems with tapered design. The long-term fixation of the cup remains an unsolved problem. Received: 14 August 1999     

Clinical and radiological results of the collarless polished tapered stem at 15 years follow-up

We prospectively followed 191 consecutive collarless polished tapered (CPT) femoral stems, implanted in 175 patients who had a mean age at operation of 64.5 years (21 to 85). At a mean follow-up of 15.9 years (14 to 17.5), 86 patients (95 hips) were still alive. The fate of all original stems is known. The 16-year survivorship with re-operation for any reason was 80.7% (95% confidence interval 72 to 89.4). There was no loss to follow-up, with clinical data available on all 95 hips and radiological assessment performed on 90 hips (95%). At latest follow-up, the mean Harris hip score was 78 (28 to 100) and the mean Oxford hip score was 36 (15 to 48). Stems subsided within the cement mantle, with a mean subsidence of 2.1 mm (0.4 to 19.2). Among the original cohort, only one stem (0.5%) has been revised due to aseptic loosening. In total seven stems were revised for any cause, of which four revisions were required for infection following revision of the acetabular component. A total of 21?patients (11%) required some sort of revision procedure; all except three of these resulted from failure of the acetabular component. Cemented acetabular components had a significantly lower revision burden (three hips, 2.7%) than Harris Galante uncemented components (17 hips, 21.8%) (p < 0.001). The CPT stem continues to provide excellent radiological and clinical outcomes at 15?years following implantation. Its results are consistent with other polished tapered stem designs.     

Hydroxyapatite-coated total hip arthroplasty: the impact on thigh pain and arthroplasty survival

The purpose of this study was to evaluate the long-term clinical outcomes of primary total hip arthroplasty using an uncemented, hydroxyapatite-coated implant. We followed a consecutive series of 164 patients, who underwent total hip arthroplasty with the Furlong fully-hydroxyapatite coated implant over a mean time period of 12.8 years. Clinical and radiological analyses were performed. Roentgenographic evaluation for the femoral side of the hip was performed using the Gruen zones, for the acetabular side using the DeLee and Charnley zones. Engh's radiological score was employed to assess fixation and stability of the stem. Clinical results were evaluated by Harris Hip Score. The mean Harris hip score was 46 preoperatively and 85 at last follow-up. The mean Engh score was 23. No hips had been revised for aseptic loosening of the femoral component. Thigh pain incidence was very low (1.2%). Survival analysis showed excellent results (95.8% at end point). The Furlong hydroxyapatite-coated implant appears as a reliable and safe option for hip arthroplasty.     

Femoral revision with the Wagner tapered stem: a ten- to 15-year follow-up study

Revision after failed femoral components may be technically demanding due to loss of peri-prosthetic bone. This retrospective study evaluated the long-term results of femoral revision using the cementless Wagner Self-Locking stem. Between 1992 and 1998, 68 consecutive hips in 66 patients underwent femoral revision using this implant. A total of 25 patients died from unrelated causes without further revision; the remaining 41 hips in 41 patients (12 men and 29 women) with a mean age of 61 years (29 to 80) were reviewed at a mean follow-up of 13.9 years (10.4 to 15.8). A transfemoral approach was used in 32 hips. A total of five stems required further revision because of infection in two, progressive subsidence in two and recurrent dislocation in one. Four hips had dislocated and eight stems had subsided ≥?10?mm. The mean Harris hip score improved from 33 points pre-operatively to 75 points at final follow-up (p < 0.001). In all, 33 stems (91.7%) showed radiological signs of stable bone fixation. The cumulative survival rates at 15.8 years with femoral revision for any reason and for stem failure as the endpoints were 92.0% (95% confidence interval (CI) 86.0% to 98.4%) and 96.6% (95% CI 92.2% to 100%), respectively. The survivorship with revision and ≥ 10 mm migration of the stem as the endpoint was 83.6% (95% CI 76.6% to 91.4%). This study shows quite good survival and moderate clinical outcome when using a monoblock tapered titanium stem for supporting the regeneration of bone in complex revision hip surgery.     

Collarless polished tapered stem: clinical and radiological results at a minimum of ten years' follow-up

We retrospectively reviewed 175 patients (191 hips) who had undergone primary cemented total hip replacement between November 1992 and November 1995 using a collarless polished double-tapered femoral component after a minimum of ten years (mean 11.08; 10 to 12.8). All stems were implanted using contemporary cementing techniques with a distal cement restrictor, pressurised lavage, retrograde cementing with a gun and proximal pressurisation. Clinical outcome was assessed using the Harris Hip score. Radiological analysis was performed on calibrated plain radiographs taken in two planes. Complete radiological data on 110 patients (120 hips) and clinical follow-up on all the surviving 111 patients (122 hips) was available. The fate of all the hips was known. At final follow-up, the mean Harris Hip score was 86 (47 to 100), and 87 of 116 patients (75%) had good or excellent scores. Survival with revision of the stem for aseptic loosening as the endpoint was 100%; and survival with revision of the stem for any reason was 95.9% (95% confidence interval 87.8 to 96.8) at ten years. All the stems subsided vertically at the stem-cement interface in a predictable pattern, at an overall mean rate of 0.18 mm per year (0.02 to 2.16), but with a mean rate of 0.80 mm (0.02 to 2.5) during the first year. The mean total subsidence was 1.95 mm (0.21 to 24). Only three stems loosened at the cement-bone interface. There was excellent preservation of proximal femoral bone stock. There was a high incidence of Brooker III and IV heterotopic ossification affecting 25 patients (22%). The collarless polished tapered stem has an excellent clinical and radiological outcome at a minimum of ten years' follow-up. The pattern and magnitude of subsidence of the stem within the cement mantle occurred in a predictable pattern, consistent with the design philosophy.     

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.     

Excellent results from proximally HA-coated femoral stems with a minimum of 6 years follow-up: a prospective evaluation of 100 patients

BACKGROUND: There have been few reports on the mid- and long-term follow-up results of the proximally HA-coated femoral stem. We evaluated this type of stem prospectively, with 6-12 years of follow-up. METHODS: The survival rate, Harris hip score and radiographic features of 106 hips in 100 consecutive patients were evaluated. The mean age at operation was 51 years (SD 8.2). RESULTS: The mean Harris hip score at the time of the latest follow-up was 95 points. Spot welds occurred in 95% of the patients and were first observed at a mean follow-up of 1.4 years in one or more of the Gruen regions, corresponding to the coated part of the femoral stem. A higher grade of stress shielding correlated with a less favorable Harris hip score and pain subscore. According to the criteria of Engh, all stems were graded as stable and durable bone-ingrown. No femoral component was revised. INTERPRETATION: At an average follow-up of 8 years, this proximally HA-coated femoral component showed favorable clinical and radiological outcome and excellent survivorship.     

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。     

Ten to fifteen-year follow-up after total hip arthroplasty with a tapered cobalt-chromium femoral component (tri-lock) inserted without cement

BACKGROUND: Fixation of the femoral component of a total hip arthroplasty without cement has had variable results. While tapered stems appear to have consistently good results, the duration of follow-up in many series has been relatively short. The purpose of this study was to present a longer-term (ten to fifteen-year) follow-up after total hip arthroplasty with insertion of a tapered femoral component without cement. METHODS: Sixty-seven total hip arthroplasties were performed with insertion of a tapered, cobalt-chromium femoral component without cement in fifty-eight patients from 1983 to 1986. Thirteen patients (fifteen hips) died prior to the fifteen-year follow-up examination, and three patients (three hips) were lost to follow-up after ten years, leaving forty-two patients (forty-nine hips) who were followed clinically for a mean of fifteen years. Thirty-seven of the forty-nine hips were followed radiographically for fifteen years, and the remaining twelve were followed for a minimum of ten years. RESULTS: The mean preoperative Charnley score was 3.0 points for pain, 2.7 points for function, and 3.2 points for motion. At the time of the final follow-up, the mean scores were 5.6, 5.6, and 5.2 points, respectively. Although no preoperative Harris hip scores were available, the mean score at the time of the latest follow-up was 92 points (range, 78 to 100 points). There were no revisions because of isolated aseptic loosening of the femoral component (although revision because of aseptic loosening of the acetabular component led to femoral component revision in seven hips). Two femoral components showed radiographic evidence of instability. At fifteen years, the prevalence of thigh pain was 2%. No femoral component that was thought to be stable, with bone ingrowth at two years, lost fixation. CONCLUSIONS: The design features of this cobalt-chromium femoral component (i.e., the collarless, tapered, wedge fit with circumferential porous coating) are thought to be crucial to the achievement of the good-to-excellent results seen in this study.     

Excellent results with cementless total hip arthroplasty and alumina-on-alumina pairing: minimum ten-year follow-up

Ceramic-on-ceramic coupling is thought to be a durable alternative to metal- or alumina-on-polyethylene pairing. No evidence exists suggesting superior clinical and radiological results for hydroxyapatite-coated stems versus uncoated stems. The aim of this study is to report the performance of an alumina-on-alumina bearing cementless total hip arthroplasty and to compare stems with a tapered design with and without hydroxyapatite coating. We prospectively analysed the results of cementless tapered femoral stems (40 hydroxyapatite-coated versus 22 uncoated stems), a metal-backed fibre mesh hydroxyapatite-coated socket and alumina-on-alumina pairing. Of 75 hips studied, 62 were available for follow-up (mean of 10.5 years after surgery). The average Harris hip score was 90. Only one hydroxyapatite-coated stem was revised for aseptic loosening. One instance of non-progressive osteolysis was detected around a screw of a cup. All other components showed radiographic signs of stable ingrowth. Hydroxyapatite coating of the stem had no significant impact on the clinical or radiological results. Total hip arthroplasty with the presented implant and pairing provides a durable standard for all patients requiring hip joint replacement against which all newer generations of cementless implants should be judged.     

Long-term survivorship of the Charnley Elite Plus femoral component in young patients

We studied prospectively the long-term results of the Charnley Elite-Plus femoral stem in 184 consecutive young patients (194 hips). There were 130 men and 54 women with a mean age of 49.1 years (21 to 60). The predominant diagnosis was osteonecrosis of the femoral head (63.6%, 117 patients). Clinical and radiological evaluation was undertaken at each follow-up. The mean follow-up was 11.2 years (10 to 12). The mean pre-operative Harris hip score was 43.4 (12 to 49) which improved to 91 (59 to 100) at the final follow-up. The survival of the femoral stem at 12 years was 99% with revision as the end-point. The mean annual linear wear of the polyethylene liner was 0.17 mm (0.13 to 0.22). The prevalence of acetabular osteolysis was 10.8% (21 hips) and osteolysis of the calcar femorale 12.9% (25 hips). A third-generation cementing technique, accurate alignment of the stem and the use of a 22 mm zirconia head were important factors in the prevention of aseptic loosening of the Elite Plus femoral stem in these high-risk young patients.     

The effect of diaphyseal biologic fixation on clinical results and fixation of the APR-II stem

This study evaluated the effect of a grit-blasted diaphyseal surface on noncemented fixation of the Anatomic Porous Replacement II stem (APR-II, Sulzer Medica Orthopaedics, Austin, TX) for improvement of clinical results and fixation. A total of 107 consecutive total hip arthroplasties with the APR-II stem, which has proximal porous coating and a diaphyseal grit-blasted surface, were performed without cement, and 99 were studied at average 4 years. Of these hips, 37 had hydroxyapatite sprayed onto the proximal porous coating, but because there were no statistical differences for performance in any category, all stems were considered as 1 group. Clinical results were measured by the Harris hip score. Radiographic measurements of fixation, osteolysis, and bone remodeling were studied by reference to Gruen zones. Of hips, 99% had a good or excellent result by Harris hip score, with an average pain score of 42.3. Of hips, 98% had >40 points, with no patient reporting thigh pain after 3 years. There were no radiolucent lines in 94% of stems, and 100% had proximal bone ingrowth fixation. Distal cortical hypertrophy associated with tip fixation occurred in 49%, whereas proximal stress shielding was present in 43% of hips. Comparison of these clinical and radiographic results with our previous experience of bone ingrowth implants (smooth stem) suggests that bone ingrowth proximally with ongrowth in the diaphysis of the femoral stem provides better clinical and radiographic results.     

Computed tomography assisted osteodensitometry in total hip arthroplasty

BACKGROUND: Periprosthetic bone remodelling is an important issue in total hip arthroplasty, which can compromise long-term outcomes. The aim of this study was to evaluate bone remodelling of the proximal femur with an uncemented hydroxyapatite-coated taper stem. METHODS: Twenty-three patients (27 hips) were included in this study. The mean age of the patients at the index operation was 57.2 years. There were 15 men and 8 women. Bone remodelling was assessed with quantitative computed tomography and the clinical outcome determined using the Harris Hip Scores. The mean preoperative Harris Hip Score was 38 points and at the 1-year follow up, it was rated 96 points. All hips were radiologically stable. RESULTS: At the 1-year follow up, we found a greater bone-density loss of the cancellous bone (ranging from 16.7 to 28.2%) compared with the cortical bone (ranging from 5.3 to 7.8%). A strong correlation was found between the low density of the cortical bone at the index operation and a higher loss of bone density at the follow up. CONCLUSION: The newly designed tapered stem showed good clinical and radiological outcomes with a proximal femoral bone loss that compares favourably with other studies.     

Total hip arthroplasty with an uncemented hydroxyapatite-coated tapered titanium stem: results at a minimum of 10 years’ follow-up in 104 hips

Background The purpose of this study was to evaluate the minimum 10-year results of primary total hip arthroplasty using an uncemented, hydroxyapatite-coated tapered stem. Radiological signs of bone remodeling are also presented. Methods We followed a consecutive series of 105 patients (115 hips), who had had an uncemented, proximally hydroxyapatite-coated Bi-Metric femoral component for a mean of 12.2 years (range 10.0–14.9 years). The average age at operation was 52 years. Detailed clinical and radiological analyses were performed after a minimum of 5 and 10 years. Eight patients (10 hips) had died, and one patient was lost to follow-up, leaving 104 hips for final evaluation. The clinical result was evaluated by the Harris Hip Score, complications, and thigh pain. Results All patients still had their femoral components in place at the final follow-up. The average Harris Hip Score after 10 years was 92 (range 50–100) with no deterioration over time. Radiologically, several signs of progressive remodeling were identified, but no stem showed signs of loosening. Conclusions The intermediate clinical and radiological results with this stem are encouraging. In the hands of various surgeons, the stem has performed well in a young, high-risk population.     

Cementless total hip arthroplasty using a threaded cup and a rectangular tapered stem. Follow-up for ten to 17 years

We carried out a clinical and radiological review of 103 cementless primary hip arthroplasties with a tapered rectangular grit-blasted titanium press-fit femoral component and a threaded conical titanium acetabular component at a mean follow-up of 14.4 years (10.2 to 17.1). The mean Harris hip score at the last follow-up was 89.2 (32 to 100). No early loosening and no fracture of the implant were found. One patient needed revision surgery because of a late deep infection. In 11 hips (10.7%), the reason for revision was progressive wear of the polyethylene liner. Exchange of the acetabular component because of aseptic loosening without detectable liner wear was carried out in three hips (2.9%). After 15 years the survivorship with aseptic loosening as the definition for failure was 95.6% for the acetabular component and 100% for the femoral component.     

Long-Term Durability of the CLS Femoral Prosthesis in Patients with Osteonecrosis of the Femoral Head

Ninety-five hips with cementless wedge-shaped tapered CLS stem were evaluated with a mean duration of 12.7 years (range, 10.7–17.3 years). All patients were young and diagnosed with osteonecrosis of the femoral head. The Harris hip score was 92 at the latest follow-up. A subsidence greater than 3 mm was found in 3 hips (3.2%). Focal femoral osteolysis was found in 12 hips (12.6%). Endosteal bone formation and bony pedestal were observed in 94 hips (98.9%) and in 26 hips (27.4%), respectively. With revision for stem loosening as the end point, the survivorship showed 98.9% (95% CI, range 96.9%–100%) at 13 years. Stem alignment and proximal femur morphology did not influence loosening of the stem (p > 0.05).