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.     

Clinical performance of a Durasul highly cross-linked polyethylene acetabular liner for total hip arthroplasty at five years

BACKGROUND: Highly cross-linked polyethylene is currently the most common articulation surface used for total hip arthroplasty. The hypothesis of the present study was that the Durasul highly cross-linked polyethylene acetabular liner would have less wear at five years than would a conventional polyethylene liner used in association with the same total hip replacement system. METHODS: Forty-three consecutive patients (fifty hips) underwent total hip replacement with an uncemented titanium porous-coated metal cup and a Durasul liner that was mated with a 28-mm cobalt-chromium femoral head. Thirty-one patients (thirty-seven hips) were followed for at least five years. Thirty-five other patients (thirty-seven hips) underwent total hip arthroplasty with the same system but with a conventional polyethylene liner, and these patients also were followed for five years. Clinical assessment was performed with use of the Harris hip score and a patient self-assessment examination. Radiographic analysis included measurements of acetabular component position, fixation, and osteolysis. Femoral head penetration of the Durasul liners was compared with that of the conventional liners. RESULTS: The clinical results as determined on the basis of Harris hip scores and patient self-assessment examinations did not differ between the Durasul group and the control group. The mean bedding-in penetration was 0.054 +/- 0.07 mm for the Durasul group and 0.059 +/- 0.154 mm for the control group. The subsequent penetration, with elimination of the bedding-in wear, resulted in a linear wear rate of 0.029 +/- 0.02 mm per year for the Durasul group, compared with 0.065 +/- 0.03 mm per year for the control group (p < 0.005). The annual penetration at one and five years was 0.074 mm and 0.011 mm, respectively, for the Durasul group, compared with 0.151 mm and 0.04 mm, respectively, for the control group. CONCLUSIONS: While the qualitative wear pattern of the highly cross-linked polyethylene liner was the same as that of the conventional polyethylene liner, the annual linear wear rate was 45% of that seen with the conventional polyethylene liner. Therefore, we believe that these early data support the continued use of this highly cross-linked polyethylene liner for total hip arthroplasty.     

Cementless total hip replacement using second-generation components: a 12- to 16-year follow-up

We reviewed 123 second-generation uncemented total hip replacements performed on 115 patients by a single surgeon between 1993 and 1994. The acetabular component used in all cases was a fully porous-coated threaded hemispheric titanium shell (T-Tap ST) with a calcium ion stearate-free, isostatically compression-moulded polyethylene liner. The titanium femoral component used was a Taperloc with a reduced distal stem. No patient was lost to follow-up. Complete clinical and radiological follow-up was obtained for all 123 hips at a mean of 14 years (12 to 16). One femoral component was revised after a fracture, and three acetabular components for aseptic loosening. No additional femoral or acetabular components were judged loose by radiological criteria. Mild proximal femoral osteolysis was identified in two hips and minor acetabular osteolysis was present in four. The mean rate of penetration of the femoral head was 0.036 mm/year (0.000 to 0.227). These findings suggest that refinements in component design may be associated with excellent long-term fixation in cementless primary total hip replacement.     

Differences in Femoral Head Penetration Between Highly Cross-Linked Polyethylene Cemented Sockets and Uncemented Liners

BackgroundThis study aimed at investigating differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets and uncemented liners during 5 years postoperatively.MethodsNinety-six patients (106 hips) with a mean age of 64.4 (range, 35-83) years underwent total hip arthroplasty using a HXLPE cemented socket or liner and were respectively divided into cemented (35 patients [37 hips]) and uncemented (61 patients [69 hips]) groups. Femoral head penetrations were evaluated on both anteroposterior (AP)-view and Lauenstein-view radiographs, and mean polyethylene (PE) wear rates were calculated based on femoral head penetration from 2 to 5 years. Multivariate analyses were performed to assess risk factors for PE wear.ResultsAt 5 years postoperatively, the cemented and uncemented groups exhibited proximal direction femoral head penetrations of 0.103 mm and 0.124 mm (P = .226) and anterior direction penetrations of 0.090 mm and 0.151 mm (P = .002), respectively. The corresponding mean PE wear rates were 0.004 mm/y and 0.009 mm/y in the AP-view (P = .286) and 0.005 mm/y and 0.012 mm/y in the Lauenstein-view (P = .168), respectively. Left-side operation and high activity were independent risk factors for PE wear on AP-view.ConclusionWhen HXLPE was used, all mean PE wear rates were very low and those of cemented sockets and uncemented liners were very similar. PE particle theory suggests that the occurrence of osteolysis and related aseptic loosening might consequently decrease.     

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.     

Head penetration into Hylamer acetabular liner sterilized by gamma irradiation in air and in a nitrogen atmosphere

We reviewed 25 consecutive primary cementless total hip arthroplasties with Hylamer acetabular liners (Hylamer group) and 12 with conventional ultra-high molecular weight polyethylene (Enduron group). Two-dimensional penetration of the femoral head into the liner was determined from anteroposterior radiographs of the pelvis. Head penetration rate was 0.37 mm/y in the Hylamer group sterilized by gamma irradiation in air (n = 6; mean length of follow-up, 3 years), 0.21 mm/y in the Hylamer group sterilized by gamma irradiation in a nitrogen atmosphere (n = 19; mean length of follow-up, 2.7 years), and 0.11 mm/y in the Enduron group (n = 12; mean length of follow-up, 3.9 years). Osteolysis was identified in 6 of the 25 hips with Hylamer liners and 1 of the 12 hips with conventional liners. There was a positive linear correlation between period from production to operation and head penetration rate with Hylamer liner sterilized by gamma irradiation in air and no correlation in a nitrogen atmosphere. Rapid oxidation by irradiation in air might not be the main cause of high rate of wear in Hylamer liners.     

Survival and polyethylene wear of porous-coated acetabular components in patients less than fifty years old: results at nine to fourteen years

BACKGROUND: Younger patients (those who are less than fifty years old) have been shown to have a high rate of failure of cemented acetabular components following total hip arthroplasty. In this report, we present the results associated with the use of an uncemented acetabular component in young patients who were evaluated at a minimum of nine years postoperatively. METHODS: Between December 1984 and December 1989, the senior author performed 174 primary total hip arthroplasties with use of a single design of porous-coated acetabular component. Seventy-one of these procedures were performed in fifty-six patients who were younger than fifty years old. Fifty-six of the seventy-one hips were available for radiographic and clinical analysis after a mean duration of follow-up of eleven years. All hips had been treated with a Harris-Galante-I porous-coated acetabular component that had been placed with a line-to-line fit and fixed with a mean of four screws. Clinical analysis was performed with use of the Harris hip score. Standardized anteroposterior radiographs were analyzed with regard to migration, radiolucent lines, pelvic osteolysis, and two-dimensional linear wear of the polyethylene. RESULTS: No metal shell was revised because of aseptic loosening, and no shell was loose at the time of the latest follow-up. A nonprogressive radiolucent line was seen in one zone in ten hips (18%) and in two zones in six hips (11%). No hip had a radiolucent line in all three zones. Pelvic osteolysis was noted in thirteen hips (23%); the osteolysis was observed in the ischium in eleven hips and around the screws in two. Survivorship analysis revealed that the probability of survival of the metal shell was 98% (95% confidence interval, 96.9% to 99.9%) at ten years. The mean rate of linear polyethylene wear (and standard deviation) was 0.15 +/- 0.10 mm/yr (range, 0.02 to 0.59 mm/yr). The wear rate was significantly increased in patients with an excellent Harris hip score (p = 0.004) and a younger age (less than thirty-eight years) (p = 0.026). With the numbers available, no relationship could be detected between the wear rate and the gender or weight of the patient, the polyethylene thickness, the abduction angle, or the femoral neck length. CONCLUSIONS: The fixation and survival of porous-coated acetabular metal shells in patients less than fifty years old was excellent after a mean duration of follow-up of eleven years. The high rate of linear polyethylene wear and the high prevalence of pelvic osteolysis are of serious concern in this patient population. Continued follow-up will be necessary to evaluate the influence of these findings on the longevity of the fixation of this prosthesis.     

The Wisconsin noncemented femoral stem: A prospective study with 5 to 9 years of follow-up evaluation

In an attempt to decrease aseptic loosening, total joint components are now being used without cement. Most components are designed to achieve fixation biologically. The radiographic results of 144 primary uncemented total hip arthroplastics and the clinical results of 89 arthroplastics that were performed using a proximally porous-coated titanium alloy femoral stem between November 1983 and June 1989 are reported. On the acetabular side, a threaded component or a hemispherical porous-coated component was used. The patients were followed prospectively for 5 to 9 years postsurgery. During the study period, the threaded acetabular component had a high failure rate. Because it was not possible to determine accurately from which component a particular sign or symptom arose, clinical analysis was restricted to only those hips without a failed or revised cup. Eighty-nine hips in 71 patients with a minimum follow-up period of 5 years were available for clinical review. Radiographic review of the femoral stem was completed on all hips with 5 or more years of radiographic follow-up evaluation, regardless of the status of the acetabular component. One hundred twelve hips in 85 patients were analyzed radiographically. At a latest mean follow-up period of 6.7 years, the mean Iowa hip score was 91.4 ± 8.0 with a 5.4% incidence of thigh pain. Throughout the followup period, the patients with thigh pain had a statistically lower mean Iowa pain subscore when compared with those patients without thigh pain (P = .0001). Endosteal erosion was seen in two hips (1.8%) and longitudinal loss of the medial neck greater than 2 mm was noted in two hips. One femoral stem was revised for aseptic loosening. The clinical results of this femoral stem equal ot exceed the published accounts of other uncemented arthroplasties. The results indicate that the stem is associated with good clinical results, minimal bone loss, and little osteolysis. Continued follow-up evaluation of patients with this femoral stem is necessary to assess the durability of these encouraging results.     

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     

H/G非骨水泥人工全髋关节置换术后聚乙烯内杯磨损临床研究

目的 对H/G非骨水泥人工全髋关节置换术后聚乙烯内杯的磨损及髋臼周围骨溶解的情况进行总结.方法 我院1991至1995年共进行58例(65髋)H/G非骨水泥人工全髋关节置换,其中35例(40髋)获得10年以上随访.对这35例(40髋)患者获得随访的病例,采用计算机数字化方法测量髋臼聚乙烯内杯的二维线性磨损.结果 35例40髋均有不同程度的磨损,磨损范围2～8 mm,平均磨损为(0.32±0.31)mm/年.10髋聚乙烯磨损超过6 mm,髋臼假体周围的骨溶解严重,并伴有金属假体的移位,其中5髋聚乙烯内杯完伞磨透,金属股骨头与金属髋臼相接触;5髋聚乙烯内杯磨损严重伴明显骨溶解,内杯松动.2髋聚乙烯内杯脱位.共实施翻修手术12例,包括更换聚乙烯内杯和金属股骨头2例、金属闩杯翻修2例、全髋翻修8例.28髋在髋臼侧发现骨溶解,其中14髋股骨侧亦有骨溶解发生.结论 本组病例所观测到的H/G髋臼聚乙烯内杯的磨损程度超过文献所报道,而且由于磨损产生的大量磨屑,导致假体周围出现明显骨溶解,直接影响到假体的稳定.关节置换术后应定期随访,避免出现严重骨溶解后增加翻修手术的困难.     

Early failure of revision total hip arthroplasty with cemented precoated femoral components: comparison with uncemented components at 2 to 8 years

This is a retrospective analysis of 2 methods of fixation of the femoral component in 86 consecutive revision arthroplasties, for which all clinical and radiographic data were recorded prospectively. There were 56 cemented revisions using precoated femoral components followed for 2 to 8 years (mean, 4 years) and 30 uncemented, proximally porous-coated femoral revisions followed for 2 to 6 years (mean, 4 years). Of the 56 cemented hips, 31 (55%) had a good or excellent clinical result. Rerevision has been performed in 10 hips, and revision of 3 loose femoral components is pending (23%). Radiographic review of 56 femoral components showed that 16 (29%) had probable or definite loosening. Of 30 cementless hips, 24 (80%) had a good or excellent clinical result. There was radiographic bone ingrowth in 22 of 30 hips (73%). Seven hips (23%) had nonprogressive subsidence, and 3 hips (10%) had progressive subsidence or loosening. Rerevision has been performed in only 2 hips (7%). The high rate of loosening (29%) and rerevision (23%) at a mean follow-up of only 4 years suggests that a precoated femoral component may place increased stress at the already damaged bone-cement interface.     

Uncemented metal-on-metal acetabular component: follow-up of 112 hips for a minimum of 5 years

Background Aseptic loosening is the major cause of implant failure. In cemented hip arthroplasty, failure of the acetabular side is mainly due to lysis caused by wear particles. By using an implant with low wear characteristics and by enhancing acetabular fixation using an uncemented implant, we aimed to reduce acetabular lysis and thereby loosening.

Patients and methods This was a retrospective cohort study of 119 hips (101 patients) that had the Uncemented Fitmore cup (Sulzer Orthopedics). In 66 patients, the femoral component was CF-30 (Sulzer) used with cement. In the remaining 35 patients, thrust plate prosthesis (TPP) (Sulzer) was used. Of the 101 patients, 94 (112 hips) were available for study. Mean follow-up of the 94 patients was 7 (5-13) years.

Results The mean preoperative Harris hip score was 38 and the mean postoperative Harris hip score was 89 at the last follow-up. Taking aseptic loosening as the endpoint, the survival rate of the Fitmore cup was 100% at 11 years.

Interpretation The uncemented Fitmore acetabular cup with second generation metal-on-metal articulation showed good results with regard to aseptic loosening in the medium term.     

Primary total hip arthroplasty with a cementless porous-coated anatomic total hip prosthesis: 10- to 12-year results of prospective and consecutive series.

We performed a prospective study in 108 consecutive patients (116 hips) who were followed for a minimum of 10 years (10-12 years) after primary total hip arthroplasty using an uncemented porous-coated anatomic (PCA) hip prosthesis. The average age of the patients at operation was 48.4 years (range, 19-85 years), and the diagnosis was avascular necrosis of the femoral head in 46 hips, neglected femoral neck fracture in 27, osteoarthrosis secondary to childhood pyogenic arthritis in 24, childhood tuberculous arthritis in 5, and miscellaneous in 14. The average preoperative Harris Hip Score was 55 points, which improved to 87 points at 11 years. Seventy-five hips (65%) were excellent, 11 (9%) were good, and 30 (39%) were poor. The overall rate of revision was 15% (17 of 116 hips). The rate of revision of the femoral component was 11% (13 of 116 hips), and the rate of revision of the acetabular component was 15% (17 of 116 hips). The prevalence of thigh pain was 28% at 11 years. The increase in the incidence of aseptic loosening of the femoral component was found to explain the high incidence of severe thigh pain at 11 years' follow-up. At 11 years, there was femoral osteolysis in 69 hips (59%) and acetabular osteolysis in 65 hips (56%). At 6 years, 20 hips (17%) showed definite wear of the polyethylene liner. At 11 years, 81 hips (70%) showed definite wear of the polyethylene liner. Because the complication rate of the PCA hip prosthesis with respect to loosening, osteolysis, and excessive wear in the polyethylene liner is high, we abandoned the use of this implant.     

The influence of technique on fixation of primary total hip arthroplasty in patients with rheumatoid arthritis

This is a prospective, consecutive study of 98 total hip arthroplasties implanted by 1 surgeon in 66 patients with rheumatoid arthritis. The mean follow-up time was 7.4 years (range, 2-13 years). All 98 acetabular components were uncemented titanium fiber metal-coated components fixed with multiple screws. Sixty-five hips had bulk or cancellous allograft for protrusio acetabuli. Following a prospective protocol based on patient age, 51 hips had an uncemented femoral component, and 47 hips had a cemented femoral component. Using the Harris Hip Score, 30 hips were rated as excellent; 44, good; 15, fair; and 9, poor. There were no early deep infections. One hybrid hip was removed for late metastatic infection at 7 years. Radiographic evaluation of 98 acetabular components showed 1 case of septic loosening, 2 cases of aseptic loosening (1 patient asymptomatic), and 1 case with severe wear and ischial osteolysis. None of the 47 cemented femoral components subsided, and osteolysis was seen in only 3 femora (7%). Of the 51 uncemented femoral components, subsidence occurred in 7 hips (14%), and osteolysis occurred in 15 hips (30%). Uncemented acetabular components have a high rate of success in patients with rheumatoid arthritis who have a total hip arthroplasty. There is a high rate of subsidence and osteolysis, however, with first-generation cementless femoral components.     

Five-Year clinical and radiographic follow-up of the uncemented long-term stable fixation total hip arthroplasty

Thirty-nine uncemented porous-coated long-term stable fixation total hip prostheses with a minimum 5-year follow-up, were retrospectively reviewed for clinical and radiographic outcome. Clinical evaluation was performed using the modified Harris Hip Score. Additionally, all patients completed a satisfaction questionnaire. Anteroposterior view and lateral view radiographs were obtained and compared with immediate postoperative films utilizing the Hip Society radiographic evaluation form for uncemented implants. The follow-up period averaged 69 months (range, 60–87 months). At the most recent follow-up visit Harris Hip Scores averaged 88 points (range, 68–100 points), with 79% good or excellent results. Of the 8 hips (6 patients) with fair or poor results, 5 patients (6 hips) were Charnley category C patients. All patients were satisfied with their surgery and all, but 2 stated that their function had significantly improved. The incidence of significant thigh pain was 13%. Calcar osteolysis was present in 13 of 39 femurs with the majority of cases being minimal. All but one femoral component demonstrated bone ingrowth. There was no distal femoral osteolysis present and no femoral revisions have been performed or are planned. Acetabular osteolysis was present in 7 of 39 hips, with 4 of the 7 centered around acetabular fixation screws. All patients who had acetabular bone loss had some degree of femoral osteolysis. Thus far, one patient has required acetabular revision secondary to osteolysis. Acetabular osteolysis in this series was more profound than on the femoral side and two other patients are being considered for revision due to pelvic side osteolysis. In conclusion, the uncemented long-term stable fixation femoral component proved to be durable in this series of patients. The circumferential porous coating on the femoral implant may protect against distal osteolysis. A concerning rate of severe pelvic osteolysis and impending failure was noted and may lead to a greater need for revision surgery with longer follow-up.     

Midterm radiographic comparison of cementless acetabular shells containing lateralized and nonlateralized liners

This retrospective study assessed the effect of lateralized acetabular inserts on polyethylene wear rates, radiographic loosening, and hip stability. Fifty-six 4-mm lateralized liners and 39 neutral liners were compared at a mean follow-up of 7.1 years. Multivariate regression analysis demonstrated a significant increase of 0.04 mm/y in polyethylene wear rate with use of lateralized liners. However, predictable cementless fixation was obtained without screws in both liner groups with no migration or radiographic signs of loosening observed for any cup. The dislocation rate for hips with lateralized liners (3.6%) was less than that for hip with neutral liners (10.3%), although the difference was not significant with the numbers available. Despite the increase in wear rate, hips with lateralized liners performed as well as those with neutral liners with regard to loosening and stability.     

Uncemented Total Hip Arthroplasty Using a Tapered Femoral Component in Obese Patients: An 18–27 Year Follow-Up Study

The purpose of this study was to evaluate the efficacy of an uncemented tapered femoral component in obese patients at a mean follow-up of 23 years. We retrospectively reviewed 119 consecutive uncemented total hip arthroplasties in 105 obese patients using a tapered femoral component between 1983 and 1987. The mean body mass index of these patients was 34 (range 30–47). Complete clinical and radiographic follow-up was obtained on the 55 hips in 47 patients who survived a minimum of 18 years (range 18–27 years). Three femoral components (6%) have been revised, none for aseptic loosening. One was loose by radiographic criteria. These results demonstrate that an uncemented tapered stem can provide excellent fixation in obese patients out to 27 years.     

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.     

Alarming wear of the first-generation polyethylene liner of the cementless porous-coated Biomet Universal cup: 107 hips followed for mean 6 years

Wear of the socket liner and resulting osteolysis are the major causes of failure in cementless hip arthroplasties. We report alarming wear of the first-generation polyethylene liner of the cementless porous-coated Biomet Universal cup. Radiographs of 107 primary hip arthroplasties were analyzed retrospectively. The mean follow-up time was 74 (47-91) months. The linear wear of the polyethylene liners was assessed using a modification of the Livermore method. The median linear wear was 1.0 (0-6.2) and the median linear wear rate was 0.17 mm/year. There was a statistically significant difference between the 28 mm and 32 mm femoral head groups both in the volumetric wear and in the volumetric wear rate. The median linear wear was 0.28 mm/year and 0.14 mm/year for the 32 mm and 28 mm heads, respectively. So far, 14 revisions have been performed or have been scheduled because of excessive wear of the polyethylene liner. In regression analysis, the factors related to the wear rate were the 32 mm size of the femoral head and screw fixation of acetabular shell. We found that the cases with calcar rounding were associated with significantly greater wear. Possible reasons for increased wear of the Hexloc liner may be the cylindrical design, thin polyethylene, and poor quality of the polyethylene. Regular clinical and radiographic follow-ups are recommended especially for hips with 32 mm femoral heads or with screw fixation. If progressive wear of the liner is observed, revision must be considered.     

Clinical and Radiographic Outcomes of Total Hip Arthroplasty With a Specific Liner in Small Asian Patients: Influence of Patient-Related,Implant-Related,and Surgical Factors on Femoral Head Penetration

Background

We evaluated the clinical and radiographic outcomes, including femoral head penetration, of total hip arthroplasty performed using a specific polyethylene (PE) liner in small Asian patients at 10 years after the index surgery. In addition, we investigated whether femoral head penetration was affected by patient-related, implant-related, and surgical factors.