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

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

Total hip replacement with a cementless acetabular component and a cemented femoral component in patients younger than fifty years of age

BACKGROUND: We have been using hybrid total hip arthroplasty (a cementless acetabular component and a cemented stem) in young patients. The purpose of this study was to determine the prevalence of aseptic loosening, polyethylene wear, and osteolysis after the use of this technique. METHODS: We studied a prospective consecutive series of sixty-four primary hybrid total hip replacements in fifty-five patients younger than fifty years old. There were forty-three men and twelve women; the average age at the time of the index operation was 43.4 years. The average duration of follow-up was 9.4 years. We used a cementless acetabular component without screw-holes and a cemented femoral component with a 22-mm head in all hips. Clinical follow-up with use of Harris hip ratings and radiographic follow-up were performed at six weeks; at three, six, and twelve months; and yearly thereafter. The sequential annual linear and volumetric wear rates were measured, and bone-remodeling and osteolysis were assessed. RESULTS: The mean preoperative Harris hip score was 44 points, which increased to 95 points at the time of final follow-up. No hip had aseptic loosening. One hip (2%) was revised because of late infection. The average linear wear (and standard deviation) was 0.96 +/- 0.066 mm, with an average annual rate of 0.096 +/- 0.013 mm. The average volumetric wear was 364.7 +/- 25.2 mm (3), with an average annual rate of 43.4 +/- 3.5 mm (3). Six hips (9%) had an osteolytic lesion of <1 cm in diameter in the calcar femorale (zone 7). CONCLUSIONS: Our results show that a hybrid arthroplasty with a cementless acetabular component and a smooth cemented femoral component (Ra, 0.6 mm) is effective for primary total hip replacement in young patients. Although there was no aseptic loosening and a low prevalence of osteolysis at the latest follow-up evaluation, the high rates of linear and volumetric wear of the polyethylene liner in these young patients remain a concern.     

No increased stem subsidence after arthroplasty in young patients with femoral head osteonecrosis: 41 patients followed for 1-9 years

BACKGROUND: Poor bone stock in patients with osteonecrosis of the femoral head may be a reason for poor outcome after hip replacement. One way of studying bone quality is to measure implant migration. We thus investigated the clinical and radiographic results of cementless THR in younger patients with femoral head osteonecrosis. PATIENTS AND METHODS: We studied hips in 41 patients (mean age 48 (25-63) years) with a cementless hip arthroplasty after late stage osteonecrosis. Clinical evaluation was by the Harris hip score, the WOMAC score and the SF-36 score. Stem subsidence was measured with the Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) at 3, 12, 24, 60, and 72 months after operation. The average duration of follow-up was 7(1-9) years, with less than 2 years for 2 patients. RESULTS: There was no revision of any hip. No radiographic or clinical stem loosening was seen. After 60 months, the cementless stems showed a median subsidence of -0.7 mm (95% CI: -0.9 to -0.2). No femoral osteolysis occurred. Femoral radiolucent lines, all < 1 mm, were seen in 10 hips. At the latest follow-up the Harris hip score was 83 (23-100) points. INTERPRETATION: Our findings for porous-coated stems in patients with femoral osteonecrosis indicate no greater risk of stem subsidence and rate of osteolysis after an average of 7 years follow-up. Thus, we continue to use uncemented stems in younger patients with femoral osteonecrosis. However, continued follow-up will be necessary to evaluate the long-term outcome.     

Contemporary total hip arthroplasty with and without cement in patients with osteonecrosis of the femoral head

BACKGROUND: The rate of failure of primary total hip arthroplasty in patients with osteonecrosis of the femoral head is higher than that in patients with osteoarthritis. The purpose of this prospective study was to document the clinical and radiographic results of arthroplasty with so-called third-generation cementing and the results of second-generation cementless total hip arthroplasty in ninety-eight consecutive patients with osteonecrosis of the femoral head. METHODS: Fifty patients who had had simultaneous bilateral total hip arthroplasty with a cemented stem in one hip and a cementless stem in the other and forty-eight patients who had had a unilateral total hip arthroplasty with a cementless stem were included in the study. A cementless acetabular component was used in all hips. The presumed cause of the osteonecrosis was ethanol abuse in fifty-seven patients, unknown in twenty-seven, fracture of the femoral neck in nine, and steroid use in five. There were eighty men and eighteen women. The mean age at the time of the arthroplasty was 47.3 years (range, twenty-six to fifty-eight years). Clinical and radiographic evaluations were performed preoperatively; at six weeks; at three, six, and twelve months; and yearly thereafter. The average duration of follow-up was 9.3 years. RESULTS: The average Harris hip scores in the group treated with unilateral arthroplasty (97 points) and the group treated with bilateral arthroplasty (94 points) were similar at the time of final follow-up. They were also similar between the group treated with cement (mean, 96 points) and that treated without cement (95 points). No component had aseptic loosening in either group. In one hip, a cemented femoral stem (2%) and a cementless cup were revised because of infection. Two cementless stems (2%) were revised because of fracture of the proximal part of the femur with loosening of the stem. Annual wear of the polyethylene liner averaged 0.22 mm in the group treated with cement (a zirconia head) and 0.14 mm in the group treated without cement (a cobalt-chromium head). The prevalence of osteolysis in zones 1 and 7 of the femur was 16% in the group treated with cement and 24% in the group treated without cement. CONCLUSIONS: Advancements in surgical technique and better designs have greatly improved the long-term survival of cemented and cementless implants in young patients with osteonecrosis of the femoral head. Although there was no aseptic loosening of the components, a high rate of linear wear of the polyethylene liner and a high rate of osteolysis in these high-risk young patients remain challenging problems.     

The use of cementless expansion acetabular component and an alumina-polyethylene bearing in total hip arthroplasty for osteonecrosis

We performed 114 consecutive primary total hip arthroplasties with a cementless expansion acetabular component in 101 patients for advanced osteonecrosis of the femoral head. The mean age of the patients at surgery was 51 years (36 to 62) and the mean length of follow-up was 110 months (84 to 129). The mean pre-operative Harris hip score of 47 points improved to 93 points at final follow-up. The polyethylene liner was exchanged in two hips during this period and one broken acetabular component was revised. The mean linear wear rate of polyethylene was 0.07 mm/year and peri-acetabular osteolysis was seen in two hips (1.9%). Kaplan-Meier analysis indicated that the survival of the acetabular component without revision was 97.8% (95% confidence interval 0.956 to 1.000) at ten years. Our study has shown that the results of THA with a cementless expansion acetabular component and an alumina-polyethylene bearing surface are good.     

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.     

Second-generation cementless total hip arthroplasty in patients with osteonecrosis of the femoral head

The results of cementless total hip arthroplasties in patients with osteonecrosis have been inferior to those in patients with other diagnoses. Fifty-eight primary total hip arthroplasties with insertion of a femoral stem with a circumferentially proximal porous coating and a cementless acetabular component were followed for a mean of 11.1 years. Fifty-seven (98%) of 58 stems were biologically stable, and one stem was loose. There were acetabular revisions in 18 hips (31%) because of polyethylene wear and osteolysis. One hip (1.7%) underwent revision of both acetabular and femoral components. Osteolysis around the acetabular component was seen on radiographs in 22 hips (37.9%). Femoral osteolysis was seen in 9 hips (15.5%), and there was no osteolysis below the lesser trochanter in any hip. Second-generation femoral prostheses provide excellent fixation in patients with osteonecrosis of the femoral head. However, a high rate of polyethylene wear and osteolysis in these high-risk patients remains a challenging problem.     

Total hip arthroplasty performed without cement in patients with femoral head osteonecrosis who are less than 50 years old

Seventy-two cementless total hip arthroplasties were performed by a single surgeon in 58 patients with the diagnosis of femoral head osteonecrosis. All patients were less than 50 years old (mean, 37 years). The mean follow-up was 84 months with a minimum of 48 months. Good-to-excellent results were maintained at final follow-up in 94% of the hips. Revision rate was 1.5% each for the cups and the stems. Mechanical failure rate was 7.6% for the cups, and 6% for the stems. If the results were analyzed excluding the data from the group of patients who received the Mittelmeier prostheses, the mechanical failure rates for the cups was 0% and for the stems was 4.2%. The probability of survival for the entire series using revision as the endpoint was 96.9% at 11 years. Survival probability decreased to 88.5% if radiographic failures were included. Excluding the Mittelmeier prostheses, survival probability was estimated to be 100% for the cups using both revision and radiographic failures as endpoints; for the stems, the survival probability was 98.0% using revision as the endpoint and 95.8% including radiographic failures. Femoral osteolysis was observed in 1.5% of the hips. No hip had acetabular osteolysis. No measurements of polyethylene wear were attempted in this study. These results appeared superior to total hip arthroplasties done with early cementing techniques in this population of young patients with femoral head osteonecrosis.     

全髋关节置换术治疗成人髋关节发育不良继发骨关节炎五年以上随访研究

目的 评价全髋关节置换术(total hip arthroplasty,THA)在成人髋关节发育不良(develop-mental dysplasia of the hip,DDH)继发骨关节炎患者中的疗效,回顾性分析该类患者THA术后5年以上的临床疗效及其影响因素.方法 对2000年2月至2002年7月在我院采用THA治疗DDH继发骨关节炎的患者55例(69髋)进行术后随访.临床评估以Harris评分为标准.影像学评估根据随访骨盆平片及患髋正、侧位X线片,观察髋臼、股骨假体位置及其周围骨质变化,测量内衬磨损率.假体生存率采用Kaplan-Meier方法进行分析,以任何原因的臼杯、股骨柄翻修或影像学假体明显松动为随访终点.结果 截至随访终点,共45例(57)髋获得5年以上随访,平均随访时间69个月,随访率为81.8%.Harris评分由术前的(46.19±18.01)分提高至末次随访时的(91.78±3.52)分,尚无假体翻修病例.聚乙烯内衬平均磨损率为(0.27±0.14)mm/年.5髋髋臼侧发生骨溶解,8髋股骨侧近端发生骨溶解.Kaplan-Meier分析假体总生存率为1.0(95%可信区间,0.98～1.00).结论 THA治疗DDH继发骨关节炎5年以上随访的影像学表现及临床效果尚可,但存在较高的聚乙烯磨损率及骨溶解发生率,对于年轻、活动量大的DDH患者,THA手术时应选择新型耐摩擦界面假体.DDH患者的定期随访尤为重要,可甲期发现骨溶解,及时给予相应的治疗.     

No increased stem subsidence after arthroplasty in young patients with femoral head osteonecrosis:41 patients followed for 1–9 years

Background?Poor bone stock in patients with osteonecrosis of the femoral head may be a reason for poor outcome after hip replacement. One way of studying bone quality is to measure implant migration. We thus investigated the clinical and radiographic results of cementless THR in younger patients with femoral head osteonecrosis.

Patients and methods?We studied hips in 41 patients (mean age 48 (25–63) years) with a cementless hip arthroplasty after late stage osteonecrosis. Clinical evaluation was by the Harris hip score, the WOMAC score and the SF-36 score. Stem subsidence was measured with the Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) at 3, 12, 24, 60, and 72 months after operation. The average duration of follow-up was 7(1–9) years, with less than 2 years for 2 patients.

Results?There was no revision of any hip. No radiographic or clinical stem loosening was seen. After 60 months, the cementless stems showed a median subsidence of –0.7?mm (95% CI: –0.9 to –0.2). No femoral osteolysis occurred. Femoral radiolucent lines, all < 1?mm, were seen in 10 hips. At the latest follow-up the Harris hip score was 83 (23–100) points.

Interpretation?Our findings for porous-coated stems in patients with femoral osteonecrosis indicate no greater risk of stem subsidence and rate of osteolysis after an average of 7 years follow-up. Thus, we continue to use uncemented stems in younger patients with femoral osteonecrosis. However, continued follow-up will be necessary to evaluate the long-term outcome.     

Charnley-Kerboull total hip arthroplasty for osteonecrosis of the femoral head a minimal 10-year follow-up study

The purpose of this retrospective study was to report the minimum 10-year follow-up results of a consecutive series of 122 cemented low-friction total hip arthroplasties performed for osteonecrosis. Revision was performed for high polyethylene wear associated with periprosthetic osteolysis and socket loosening in 6 hips, and for deep sepsis in 1. The survival rate at 15 years, using revision for any reason as the end point, was 88.5%. Among the variables studied in this series, the only factor associated with a higher risk of revision was a socket wear rate greater than 0.1 mm/y. This series indicated that cemented low-friction total hip arthroplasty performed for avascular necrosis could grant satisfactory long-term results, provided that polyethylene socket wear remained below 0.1 mm/y.     

Primary total hip arthroplasty with the AML total hip prosthesis

Primary total hip arthroplasty using an uncemented AML total hip prosthesis (trispiked cup and a 4/5 porous coated stem) was performed in 50 patients (52 hips). The average age of the patients at the time of surgery was 47.6 years (range, 19-68 years), and the diagnosis was osteonecrosis of the femoral head in 18 hips, osteoarthritis in 16, fracture of the femoral neck in 14, osteoarthrosis secondary to childhood pyogenic arthritis in two, childhood tuberculous arthritis in one, and traumatic arthritis in one. The average followup was 11.3 years (range, 11-12 years). The average preoperative Harris Hip Score was 59 points, which improved to 90 points. Twenty-five (48%) hips had excellent results, 14 (27%) had good results, three (6%) had fair results, and 10 (19%) had poor results. The overall rate of revision was 15% (eight hips). The rate of revision of the femoral component was 2% (one hip), and the rate of revision of the acetabular component was 15% (eight hips). Twenty (38%) hips had acetabular and femoral osteolysis. Nine (17%) hips had femoral osteolysis only. Thirty-four (65%) hips had an average of 3.3 mm (range, 2-12 mm) of wear in the polyethylene liner. The average wear rate was 0.29 mm (range, 0.17 to 1.04 mm) per year.     

Second-generation cementless total hip arthroplasty. Eight to eleven-year results.

BACKGROUND: Second-generation cementless femoral components were designed to provide more reliable ingrowth and to limit distal osteolysis by incorporating circumferential proximal ingrowth surfaces. We examined the eight to eleven-year results of total hip arthroplasty with a cementless, anatomically designed femoral component and a cementless hemispheric acetabular component. METHODS: Ninety-two consecutive primary total hip arthroplasties with implantation of a femoral component with a circumferential proximal porous coating (Anatomic Hip) and a cementless hemispheric porous-coated acetabular component (Harris-Galante II) were performed in eighty-five patients. These patients were prospectively followed clinically and radiographically. Six patients (seven hips) died and five patients (seven hips) were lost to follow-up, leaving seventy-four patients (seventy-eight hips) who had been followed for a mean of ten years (range, eight to eleven years). The mean age at the time of the arthroplasty was fifty-two years. RESULTS: The mean preoperative Harris hip score of 51 points improved to 94 points at the time of final follow-up; 86% of the hips had a good or excellent result. Thigh pain was reported as mild to severe after seven hip arthroplasties. No femoral component was revised for any reason, and none were loose radiographically at the time of the last follow-up. Two hips underwent acetabular revision (one because of dislocation and one because of loosening). Kaplan-Meier survivorship analysis was performed with revision or loosening of any component as the end point. The ten-year survival rate was 96.4% +/- 2.1% for the total hip prosthesis, 100% for the femoral component, and 96.4% +/- 2.1% for the acetabular component. Radiolucencies adjacent to the nonporous portion of the femoral component were seen in sixty-eight (93%) of the -seventy-three hips with complete radiographic follow-up. Femoral osteolysis proximal to the lesser trochanter was noted in four hips (5%). No osteolysis was identified distal to the lesser trochanter. Periacetabular osteolysis was identified in twelve hips (16%). Five patients underwent exchange of the acetabular liner because of polyethylene wear. CONCLUSIONS: This second-generation cementless, anatomically designed femoral component provided excellent clinical and radiographic results with a 100% survival rate at ten years. The circumferential porous coating of this implant improved ingrowth and prevented distal osteolysis at a mean of ten years after the arthroplasty.     

Serial measurement of polyethylene wear of well-fixed cementless metal-backed acetabular component in total hip arthroplasty: an over 10 year follow-up study

Serial radiographic measurements of polyethylene wear were performed in 38 hips (33 patients) with primary cementless total hip arthroplasty (THA). The average follow-up period was 131.8 months. All prostheses were assessed as radiographically stable at the latest follow-up. A two-dimensional method was used to calculate the relative migration of the femoral head center to the cup center. The average total linear wear and wear rate were 1.22 mm and 0.11 mm/year, respectively. The degree of wear in the first 2 postoperative years accounted for nearly 40% of the total wear at the end of the study (average follow up: 131.8 +/- 10.0 months, +/-SD). The migration of the femoral head at an average period of 3. 4 months after operation accounted for 56% of the amount of wear in the first 2 years. Wear rate decreased gradually with time and stabilized after the fourth year. However, in 2 patients, a progressive increase in the wear rate was associated with severe osteolysis and failure of THA. Both creep and wear contributed to the femoral penetration into the polyethylene liner. The influence of creep cannot be ruled out, especially in the early period after operation. Polyethylene wear is a multifactorial process, and the study of individual wear patterns might be useful in identifying patients who are at risk of late failure of THA.     

Third-generation ceramic-on-ceramic total hip arthroplasty in patients younger than 30 years with osteonecrosis of femoral head

The purpose of this study was to evaluate the functional and radiographic results of patients younger than 30 years who underwent cementless third-generation ceramic-on-ceramic total hip arthroplasty for osteonecrosis of the femoral head. Forty-one patients (56 hips) with a minimum follow-up of 6 years were included. In all cases, third-generation ceramic-on-ceramic articulation was used. Average Harris Hip Scores improved from 52.9 preoperatively to 98.2, and Western Ontario and McMaster Universities Osteoarthritis Index score, from 95.2 to 25.2. Thirty-nine patients returned to their normal occupations. No aseptic loosening or osteolysis was observed. Total hip arthroplasty performed using third-generation ceramic-on-ceramic bearings for osteonecrosis of femoral head was found to provide satisfactory clinical and radiologic results, especially in active, young patients.     

双极人工股骨头与全髋关节置换术在老年患者股骨头缺血性坏死FicatⅢ期的中远期随访比较

目的比较生物型双极人工股骨头置换与全髋置换术治疗老年FicatⅢ期股骨头缺血性坏死患者的中远期疗效。方法对获得随访的61例（64髋）FicatⅢ期股骨头缺血性坏死患者,其中23例（24髋）行生物型双极人工股骨头置换、38例（40髋）行全髋关节置换术对其行回顾分析比较,观察手术前后Harris评分和术后髋部疼痛、影像学变化等情况。结果术后随访5～13年（平均8年）,末次随访Harris评分全髋置换组（88.5±8.9）分,较股骨头置换组（73.5±8.3）分高,差异有统计学意义（t=6.69,P〈0.05）。在疼痛发生率及翻修率上股骨头置换组分别为37.5%（9/24）、29.2%（7/24）,均较全髋置换组10%（4/40）、7.5%（2/40）高,差异有统计学意义（2=5.41、2=5.39,P均〈0.05）。随访X线检查假体位置,股骨头置换组9例出现髋臼磨损,发生率为37.5%;全髋置换组髋臼松动率为2.5%（1/40）,假体柄松动率为5%（2/40）;股骨头置换组5例出现股骨柄松动,发生率为20.8%（5/24）,两组在股骨柄松动发生率上差异无统计学意义（2=2.41,P〉0.05）;在股骨侧骨溶解发生率上股骨头置换组20.8%（5/24）与全髋关节置换组22.5%（9/40）间的差异无统计学意义（2=2.44,P〉0.05）。结论治疗老年FicatⅢ期股骨头缺血性坏死选择双极股骨头置换术应慎重,对于大多数患者,应积极选用生物型全髋置换术。     

Uncemented Harris-Galante total hip arthroplasty in patients with osteonecrosis of the femoral head. A 10-16-year follow-up study

Background There have only been a few reports regarding the long-term results of uncemented THAs in patients with osteonecrosis.

Patients and methods We evaluated the long-term results of 65 consecutive uncemented total hip arthroplasties (Harris-Galante type I prostheses) in 54 men (59 hips) and 5 women (6 hips) with osteonecrosis of the femoral head. The mean age was 53 (33-64) years. The mean duration of follow-up was 12.5 (10-16) years.

Results 9 femoral stems and 3 acetabular metal shells were revised. 2 polyethylene liners were changed due to excessive wear. A girdlestone procedure was done in 2 patients (2 hips) due to delayed deep infection. The mean polyethylene wear was 0.14 mm per year. 3 non-revised hips had pelvic osteolysis and 18 had femoral osteolysis. The 15-year survival rates, using failure defined as the removal of any component for any reason, were 85 (95% CI; 79-91)% for the acetabular and 80 (74-86)% for the femoral component and 70 (63-77)% for any of the components.

Intepretation The first generation of the HGP design was frequently associated with pain, unstable fixation, and osteolysis. Excessive wear was frequent. The cup showed better durability than the stem.     

Influence of acetabular coverage on hip survival after free vascularized fibular grafting for femoral head osteonecrosis

BACKGROUND: Osteonecrosis of the femoral head frequently results in collapse of the head and subsequent arthrosis of the joint. Surgical treatment has been based entirely on the evaluation of the femoral side of the hip joint, with little consideration given to the possible influence on outcome of the orientation of the acetabulum. METHODS: We retrospectively reviewed a consecutive series of 200 hips in 160 patients with osteonecrosis of the femoral head who had undergone free vascularized fibular grafting between 1997 and 1998. The mean duration of clinical follow-up was 7.5 years. Ninety-one hips in seventy-one patients were evaluated radiographically for evidence of progression of femoral head collapse at a minimum of two years, and a mean of three years, postoperatively. We defined conversion to a total hip arthroplasty and progression of femoral head collapse as the failure end points, and we analyzed the association of the acetabular center-edge angle of Wiberg, the area and laterality of the lesion, the amount of preoperative collapse of the femoral head, and the etiology of the osteonecrosis with the likelihood of failure. RESULTS: Forty-eight (24%) of the 200 hips had undergone conversion to a total hip arthroplasty at the time of the final clinical follow-up. In addition, 15% (fourteen) of the ninety-one hips with sufficient radiographic follow-up demonstrated progression of femoral head collapse at the time of the final radiographic examination. Of the hips with a center-edge angle of 30 degrees , 10% had progressive collapse (p = 0.002) and 6% were converted to a total hip arthroplasty (p < 0.001). Neither the etiology nor the size of the lesion was significantly correlated with progression of collapse or conversion to a total hip arthroplasty. CONCLUSIONS: Patients with osteonecrosis of the femoral head and a suboptimal center-edge angle of the hip are at substantial risk for progression of femoral head collapse and conversion to a total hip arthroplasty following free vascularized fibular grafting. An estimation of the degree of hip dysplasia should be included in the preoperative assessment of patients with osteonecrosis of the femoral head for prognostic and possibly surgical planning purposes.     

Hybrid total hip arthroplasty with a precoated offset stem. Four to nine-year results

BACKGROUND: Use of modern cementing techniques for fixation of femoral components in total hip arthroplasty has had excellent clinical and radiographic results in most patients. However, several authors have described early loosening of femoral components with roughened and precoated finishes. The purpose of this study was to examine the performance of the precoated Iowa stem, which has increased offset, and to compare the results with those of another cemented precoated femoral component with standard offset used at our institution. METHODS: We carried out a prospective analysis of 102 primary hybrid total hip arthroplasties (a cementless acetabular component and a cemented femoral component) performed with use of the Iowa femoral component in ninety-five patients at our institution. The Iowa stem was used in hips that required greater offset than is available with standard stems as determined by preoperative templating. The average age of the patients at the time of the index procedure was sixty-nine years. Sixteen patients (seventeen hips) died before the forty-eight-month minimum follow-up period had elapsed. Two patients were lost to follow-up, and radiographic follow-up was incomplete for one. The mean duration of clinical and radiographic follow-up of the remaining eighty-two hips in the seventy-six surviving patients was sixty-five months (range, forty-eight to 104 months). RESULTS: The average preoperative Harris hip score of 47 points (range, 16 to 69 points) improved to an average of 87 points (range, 24 to 100 points) at the time of the review. Two hips underwent femoral component revision. Four femoral stems were radiographically loose at an average of thirty-four months. Femoral osteolysis was seen in five hips (6 percent) at an average of fifty-four months postoperatively. No acetabular component was revised because of aseptic loosening. According to Kaplan-Meier analysis, the seven-year survival rate, with an end point of femoral revision, osteolysis, or stem debonding, was 90.6 percent (95 percent confidence interval, 0.87 to 0.94). CONCLUSIONS: The prevalence of revision, osteolysis, and loosening after total hip arthroplasty with the Iowa femoral component at our institution was higher than that seen in our series of Harris Precoat stems, which had a survival rate of 98.4 percent (95 percent confidence interval, 0.97 to 1.00) at ten years with the same end points. The design of the Iowa stem may make it difficult to achieve a good cement mantle, and, in combination with the geometry and increased offset of the stem, may compromise the long-term survival of this cemented femoral component.     

Arthopor 2 acetabular component with screw fixation in primary hip arthroplasty: A 7- to 9-year follow-up study

The first 100 consecutive primary hip arthroplasties with the Arthopor 2 acetabular component (Joint Medical Products, Stamford, CT) with supplemental screw fixation performed by the senior author were prospectively studied. The mean patient age was 57 years. Seventy-seven cemented and 23 cementless stems were placed, with 32-mm femoral heads used in most of the patients. Eighty-six hips were reviewed at 7–8.8 years (mean, 7.8 years). The mean Harris hip score at final follow-up evaluation was 94 points. No cups have been revised, although 2 cups in patients with radiation osteonecrosis were loose radiographically. One patient underwent revision of a severely worn liner. Despite a relatively high mean linear wear rate of 0.27 mm/y (range, 0.13–0.57 mm/y), no radiographic evidence of pelvic osteolysis was seen. The Arthopor 2 cup performed well with respect to pelvic osteolysis, despite the presence of substantial polyethylene debris. The relatively high polyethylene wear rate is attributed in part to the younger patient population and the use of 32-mm femoral heads paired with thin polyethylene liners.