Hydroxyapatite-coated total hip replacements in patients 65 years of age and over.

Prospective review examined 69 patients aged over 65 years (mean: 73 years; range: 65 to 85 years) who underwent 72 primary hydroxyapatite-coated total hip replacements by one surgeon. The femoral component used was titanium alloy coated by hydroxyapatite on the proximal third and the acetabular component was spherical and unthreaded, coated with hydroxyapatite. All patients were evaluated clinically by Harris Hip Score and radiologically using Engh's criteria with a mean follow-up of 86 months (range: 29 months to 10 years). Preoperative radiologic evaluation for osteoporotic bone using the Singh index was performed. Average Harris Hip Score increased from 45 before surgery to 89 at last follow-up. Two femoral and one-acetabular components were shown to probably be loose, but none was definitely loose or unstable by Engh's criteria. There was no correlation between clinical and radiologic results with respect to age, sex, and preoperative diagnosis. In contrast, significant statistical correlation was demonstrated between Charnley groups A or B, and group C, with regard to the Harris Hip Score (p = 0.047). There was no correlation between Charnley groups and radiological results. There was no statistical difference between patients with osteoporotic bone (Singh 1-3) and non-osteoporotic bone (Singh 4-6) with respect to clinical and radiologic evaluation. These early clinical and radiologic results compare favorably with those of hydroxyapatite-coated total hip replacements for younger patients and cemented total hip replacements in older patients. We recommended that hydroxyapatite-coated total hip replacements should not be reserved for younger patients. They can be used safely in patients over 65 years of age, promising minimal postoperative thigh pain and satisfactory clinical and radiologic results.     

Staged bilateral total hip arthroplasty using rough and smooth surface femoral stems with similar design: 10-year survivorship of 48 cases

BACKGROUND: Various studies have reported good long-term results using femoral stems with either smooth or rough surfaces. In this retrospective cross-sectional survivorship study, we reviewed the 10-year results of 51 bilateral staged cemented total hip arthroplasties using the Harvard or the Charnley femoral stems-which have almost similar geometry but a different surface finish. METHODS: 51 patients were reviewed at median interval of 10 (Harvard group) and 11 years (Charnley group) after the primary operation. We evaluated cement mantle thickness, alignment of the components, presence of radiolucent lines, and aseptic loosening. Kaplan-Meier analysis was performed to calculate the survival rate using various endpoints. RESULTS: 8 hips in the Harvard group were revised for aseptic loosening of the femoral component at a median interval of 6.3 years after the primary procedure. 3 hips in the Charnley group were revised for aseptic loosening of the femoral and acetabular components between 10 and 11 years after the primary procedure. The 10-year survival rate for the femoral component using revision surgery for aseptic loosening as an endpoint was 80% (95% CI: 31-42) and 95% (95% CI: 44-47) in the Harvard and the Charnley group, respectively. Cox regression analysis did not reveal any statistically significant effect of various radiographical parameters on the survival rate (p < 0.05). INTERPRETATION: Our results demonstrate that in the group of patients studied, the femoral stem component with the matt surface finish had less satisfactory 10-year survival than the femoral stem of similar design which had a smooth surface finish.     

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.     

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

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

Long-term results of a hydroxyapatite-coated femoral component in total hip replacement: a 15- to 21-year follow-up study

Between 1986 and 1991 we implanted 331 consecutive Furlong hydroxyapatite-coated femoral components of a total hip replacement in 291 patients. A cemented acetabular prosthesis was used in 217 hips and a hydroxyapatite-coated component in 114. We describe the long-term clinical and radiological survival of the femoral component at a mean follow-up of 17.5 years (15 to 21). Only two patients (0.68%) were lost to follow-up. With revision of the femoral component for any reason as the endpoint, the survival at a mean of 17 years was 97.4% (95% confidence interval 94.1 to 99.5), and with revision for aseptic loosening as the endpoint it was 100%. The survival at a maximum of 21 years with revision of the femoral component for any reason as the endpoint was 97.4% (95% confidence interval 81.0 or 99.5). These results compare favourably with the best long-term results of cemented or uncemented femoral components used in total hip replacement.     

The Charnley versus the Spectron hip prosthesis: radiographic evaluation of a randomized, prospective study of 2 different hip implants.

A total of 410 hips were randomized to treatment with either a Charnley (206 hips) or a Spectron (204 hips) total hip arthroplasty. The patients were operated on by a standardized procedure using a contemporary cementing technique and were followed after 1, 3, 5 to 6, and 10 years. The postoperative radiographs showed a significantly increased rate of malalignment and consequently low grade of cement mantle quality of the Charnley stem compared to the Spectron. No differences concerning cement mantle quality or positioning were found between the Charnley ogee cup and the metal-backed Spectron. Evaluation of the follow-up radiographs revealed 10 loose Charnley stems and 1 loose Spectron stem and 4 loose Charnley ogee cups and 23 loose Spectron metal-backed cups. The differences of revision rate for the femoral and acetabular components of the 2 prostheses were significant (P = .03, Charnley femoral component more frequent; P = .03, Spectron acetabular component more frequent). The radiographic evaluation strengthened this disparity. Poor wear characteristics of the metal-backed Spectron cup are perhaps the main reason for the highly significant difference in mechanical failure rate between the 2 cups. We therefore propose that metal-backing of cemented cups should be avoided, at least when combined with larger femoral heads. The difficulty in positioning the Charnley stem with an adequate cement mantle, especially in the absence of trochanteric osteotomy, might explain the inferior Charnley stem longevity in this study.     

Staged bilateral total hip arthroplasty using rough and smooth surface femoral stems with similar design: 10-year survivorship of 48 cases

Background?Various studies have reported good long-term results using femoral stems with either smooth or rough surfaces. In this retrospective cross-sectional survivorship study, we reviewed the 10-year results of 51 bilateral staged cemented total hip arthroplasties using the Harvard or the Charnley femoral stems—which have almost similar geometry but a different surface finish.

Methods?51 patients were reviewed at median interval of 10 (Harvard group) and 11 years (Charnley group) after the primary operation. We evaluated cement mantle thickness, alignment of the components, presence of radiolucent lines, and aseptic loosening. Kaplan-Meier analysis was performed to calculate the survival rate using various endpoints.

Results?8 hips in the Harvard group were revised for aseptic loosening of thefemoral component at a median interval of 6.3 years after the primary procedure. 3 hips in the Charnley group were revised for aseptic loosening of the femoral and acetabular components between 10 and 11 years after the primary procedure. The 10-year survival rate for the femoral component using revision surgery for aseptic loosening as an endpoint was 80% (95% CI: 31–42) and 95% (95% CI: 44–47) in the Harvard and the Charnley group, respectively. Cox regression analysis did not reveal any statistically significant effect of various radiographical parameters on the survival rate (p < 0.05).

Interpretation?Our results demonstrate that in the group of patients studied, the femoral stem component with the matt surface finish had less satisfactory 10-year survival than the femoral stem of similar design which had a smooth surface finish.

?     

Hydroxyapatite-coated RM cup in primary hip arthroplasty

We reviewed 113 patients with 127 primary total hip arthroplasties using a hydroxyapatite-coated RM (Robert Mathys) cup. Average patient age was 61 (30-70) years and mean follow-up was 9.4 (6-13) years. Four patients were lost to follow-up and nine patients died of unrelated causes during the course of the study. Three acetabular components were revised; two cups were radiologically loose and one was revised for marginal erosion. No radiolucency was noted in any of the three zones in the remaining cups. There were no cases of cup migration or dislocation. The life table method predicted a 10-year survival rate of 97.9% with revision of the acetabular component for any cause as the endpoint.     

Cementless acetabular fixation at fifteen years. A comparison with the same surgeon's results following acetabular fixation with cement

BACKGROUND: Loosening of the acetabular component is the major long-term problem associated with total hip arthroplasty with cement. The purpose of the present study was to evaluate the minimum thirteen-year results associated with cementless acetabular components that had been inserted by a single surgeon and to compare them with the results associated with cemented acetabular components that had been inserted by the same surgeon. METHODS: One hundred and twenty consecutive, nonselected primary total hip replacements were performed in 108 patients with use of a Harris-Galante-I cementless acetabular component and a cemented femoral component with a 28-mm head. The patients were evaluated clinically with use of a standard terminology questionnaire, and they were evaluated radiographically for loosening, component migration, wear, and osteolysis. The rates of revision for aseptic loosening and radiographic evidence of loosening for this cohort were compared with the rates for four previously reviewed consecutive series of hips in which the acetabular component had been inserted with cement. All patients were managed by the same surgeon, were followed for thirteen to fifteen years, and were evaluated with use of the same two criteria (revision and loosening) as the end points for Kaplan-Meier analysis. RESULTS: Sixty-six patients (seventy-two hips) were living and forty-two patients (forty-eight hips) had died after thirteen to fifteen years of follow-up. No acetabular component had been revised because of aseptic loosening, and no acetabular component had migrated. With revision of the acetabular component for any reason as the end point, the survival rate was 81% +/- 8% at fifteen years. With revision of the acetabular component for clinical failure (osteolysis, wear, loosening, or dislocation) as the end point, the survival rate was 94% +/- 8% at fifteen years. Among the seventy hips with at least thirteen years of radiographic follow-up, five had pelvic osteolysis and three had had revision of a well-fixed acetabular component because of pelvic osteolysis secondary to polyethylene wear. The mean linear wear rate was 0.15 mm/yr (0.12 mm/yr when one outlier was excluded). CONCLUSIONS: In terms of fixation, Harris-Galante-I cementless acetabular components performed better than did cemented 22-mm-inner-diameter Charnley acetabular components as well as 28-mm-inner-diameter all-polyethylene and metal-backed acetabular components that had been inserted by the same surgeon. However, the rate of wear was greater in association with the Harris-Galante-I cementless components than it was in association with the Charnley cemented all-polyethylene components.     

Ten-year survivorship of rough-surfaced femoral stem with geometry similar to Charnley femoral stem

The aim of this study is to review the 10-year results of 269 cemented total hip arthroplasties performed using the Harvard femoral stem with matte surface finish and Charnley stem-like geometry. This is a retrospective cross-sectional survivorship study. We retrospectively reviewed the results of 269 cemented total hip arthroplasties performed using the Harvard femoral stem in 257 patients (men/women 93:164, mean age 71.2 years) between 1990 and 1994. The median duration of follow-up for the surviving implants was 118 (range 60-129) months. Radiographs were reviewed to evaluate the type of osteoarthritis, cement mantle thickness, alignment of the components, presence of aseptic loosening, and radiolucent lines. Kaplan-Meier survival analysis and Cox proportional hazards analysis were performed to evaluate 10-year survival and the impact of various radiological parameters on the prosthesis survival respectively. Of the 248 eligible patients (260 hips), 6 patients (7 hips) were lost to follow-up, and 67 patients had died at the time of the study; 36 hips (35 patients) underwent revision surgery for aseptic failure (median duration 60 months, range 12-125 months), and 11 hips were revised for septic failure (median duration 24 months, range 10-53 months from the index procedure). The femoral component was revised in all patients, whereas the acetabular component was revised in 27 patients. Ten-year survival for the femoral and acetabular components using aseptic loosening (with and without revision surgery) as an end point was 77.5% (71.5%-83.5%) and 91.1% (87.2%-95%), respectively. Cox regression analysis did not reveal a statistically significant (P > 0.05) effect of various radiological parameters on survival rate. Our results demonstrate that the matte surface finish femoral component (with geometry similar to Charnley femoral component) has less satisfactory long-term survival rate.     

Comparison of Charnley and T-28 total hip arthroplasty

A retrospective review of a matched series of 40 Charnley and 40 T-28 total hip arthroplasties was performed. The mean follow-up period after surgery was 5 1/2 years. The clinical status and detailed radiographic appearance were carefully evaluated prior to operation, two months after operation, and at the final follow-up examination. The clinical results were similar. The Charnley femoral components tended to be positioned in a more valgus orientation than the T-28 prostheses by 2.2 degrees (p less than 0.02). After operation, the patients with T-28 prostheses had larger leg-length discrepancies than the patients with Charnley prostheses (p less than 0.01). Calcar resorption was not significantly different between the two groups, nor were subsidence of the femoral components and migration of the acetabular components. A collared T-28 femoral component has little clinical advantage over a noncollared prosthesis with respect to calcar resorption and femoral component subsidence.     

Radiological factors influencing femoral and acetabular failure in cemented Charnley total hip arthroplasties

We have made a retrospective review of 185 cemented Charnley total hip arthroplasties performed between 1970 and 1974 to determine the relationships between radiological variables and failure of the femoral and acetabular components. We measured the acetabular wear, the orientation of the cup, the thickness and consistency of acetabular and femoral cement mantles, radiolucency and femoral alignment. The mean follow-up was for 11.7 years. Femoral loosening was demonstrable radiologically in 15 hips (8.1%), ten (5.4%) of which were revised during the period of follow-up. Only when the first postoperative radiograph showed a thin cement mantle in Gruen zone 5 was there a significant association with failure of the femoral component. There were 12 loose acetabular components (6.5%), nine (4.8%) of which were revised. When the initial radiograph after operation showed radiolucency in DeLee and Charnley zone 1, the incidence of acetabular loosening was 28.21%. If such radiolucency was not present, the incidence of acetabular loosening was only 0.69%. Our findings emphasise the importance of careful cementing.     

A modification of Charnley low-friction arthroplasty. Representative ten-year follow-up results of the St. Georg prosthesis

From the stimulus offered by John Charnley in 1962, Hans Wilhelm Buchholz developed the St. Georg hip implant in Hamburg. The design differed from that of Charnley notably in the size of the femoral head. The results of early operations performed in Hamburg are confined largely to the most cogent form of failure, mechanical loosening of one or both components. Four representative years (1968-1971) were selected for this purpose, and survival curves were constructed for 1971 patients of different age and preoperative diagnosis. In conventional terms, the rate of mechanical loosening for the femoral component is 1.9%, for the acetabular component 2.4%, and for both components 7.5% for a ten or more year follow-up period. The principle annunciated by Charnley suggesting that total joint arthroplasty be performed in large units or special hospitals is strongly recommended.     

Cementless hemispheric hydroxyapatite-coated sockets for acetabular revision

This study describes our experience with a hydroxyapatite-coated uncemented hemispherical component used for revision of 72 patients with aseptic loosening of the acetabular component. Preoperative Paprosky classification of the acetabular defects was 1 type I, 35 type II, and 36 type III; according to American Academy of Orthopaedic Surgeons, 14 segmental, 10 cavitary, and 48 combined. The mean follow-up was 7.6 years (range, 5.0-13.0). Complications were seen in 7 cases (9.6%). Seventy acetabular components (97.2%) showed bone ongrowth on the radiographs. The survival rate was 90.8% after a mean follow-up of 7.6 years (range, 5.0-13.0) when revision for any reason is the end point (confidence interval, 80.5%-100%) and 98.1% (confidence interval, 94.5%-100%) when aseptic loosening of the cup is the end point. We conclude that hydroxyapatite-coated cups for acetabular revision show promising results.     

Total hip arthroplasty using two different cementless tapered stems.

The authors report their 15-year experience with primary total hip arthroplasty using collarless, tapered, porous-coated femoral stems (Trilock and Taperloc) in patients with osteoarthritis, rheumatoid arthritis, and in octogenarians. Excellent clinical results were achieved in all groups at latest followup. For the patients with Trilock stems, Taperloc stems, and patients who were octogenarians and patients with rheumatoid arthritis, Charnley pain scores were 5.6, 5.5, 5.7, and 5.7; Charnley function scores were 5.2, 5.1, 4.2, and 5.3; Harris hip scores were 92, 92, 82, and 93 points, respectively. There was a 2% rate of thigh pain with the Trilock, 4% with Taperloc, 4% in octogenarians, and 2% in patients with rheumatoid arthritis. In 96% of the patients in the Trilock group, in 100% of the patients in the Taperloc group, in 100% of the patients who were octogenarians, and in 100% of the patients with rheumatoid arthritis, femoral components showed radiographic evidence of bone ingrowth. There were six (12%) femoral component revisions in the Trilock group (all secondary to nonmodularity of the component at the time of acetabular revision), one femoral component revision in the Taperloc group and no femoral component revisions in the patients who were octogenarians or who had rheumatoid arthritis. Design features (collarless tapered wedge fit, circumferentially porous-coated) virtually ensure bone ingrowth and are thought to be responsible for the excellent clinical results and longevity.     

Polyethylene wear in prosthetic hips with loose components

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

Hydroxyapatite-coated femoral stem/porous-coated acetabulum survivorship at 15 years

At 10 years, we reported survivorship of the Omnifit hydroxyapatite-coated femoral stem and the Omnifit-PSL porous-coated dual-radius acetabular shell (Stryker, Mahwah, NJ) with polyethylene liners sterilized by gamma radiation in air. Our 15-year follow-up examines survivorship and functional outcomes of this system. Ninety-two patients (98 hips) were identified from our database who had been involved with the prior study. The mean follow-up was 14.7 years (range, 11.8-17.0 years). Survival of the stem and cup was 98.8% and 69%, respectively. Osteolysis was seen in 56% of the proximal femur and 5% of the distal femur. This hydroxyapatite-coated stem continues to perform well at 15 years despite poor acetabular results. The performance of this acetabular component is consistent with previous literature.     

Minimum 10-year results of a tapered cementless hip replacement.

Seventy-one total hip arthroplasties with a cementless, wedge fit, cobalt chrome femoral component were reviewed in 60 patients at a minimum 10-year followup (mean, 11.5 years). For the femoral component, the mechanical failure rate was 5% and the revision rate for aseptic loosening was 0%. The mean Charnley scores for pain, function, and motion changed from preoperative mean values of 3.0, 2.7, and 3.2 to followup mean values of 5.7, 5.5, and 5.2, respectively. The followup mean Harris hip Score was 91. The incidence of thigh pain was 1.4% at 10-year followup. Ninety-five percent of femoral components showed radiologic evidence of stable, bone ingrowth fixation, whereas loosening was seen in 5% of stems. Despite the high incidence of acetabular osteolysis, no osteolysis was seen on the femoral side distal to the lesser trochanter. Nonmodularity of the femoral component led to unavoidable revision of stably fixed femoral components in seven (9.8%) hips during the revision of a loose socket. Design features (collarless, tapered, wedge fit, and circumferentially porous coated) were thought to be crucial to the superlative results with the cobalt chrome femoral component.     

Five-year follow-up with a ceramic sandwich cup in total hip replacement

The results of the first 56 consecutive total hip replacements using a new cementless, sandwich (alumina-polyethylene-titanium) acetabular component are reported. From March 1994 to March 1995 we operated on 39 female and 17 male patients; their mean age was 62.8 years (range 32-85 years). The Harris Hip Score was used for clinical evaluation. X-rays were examined according to the DeLee and Charnley method. At an average follow up of 62.4 months, 51 patients had complete clinical and radiographic data. For them, we recorded a good clinical result (average HHS 90.6), and we could detect no acetabular radiolucencies on X-rays. At the 5-year follow-up the results of this ceramic acetabular cup are quite encouraging. As a matter of fact, although the clinical results are very similar to those reported by other authors with conventional ceramic-polyethylene coupling prosthesis, the absence of periacetabular radiolucency and socket migration could mean less debris formation, less acetabular wear and, consequently, a longer life of the implant.     

Hydroxyapatite-coated acetabular components. Histological and histomorphometric analysis of six cups retrieved at autopsy between three and seven years after successful implantation.

BACKGROUND: Important questions remain regarding the use of hydroxyapatite-coated acetabular components in total hip arthroplasty. What is the relation of resorption of the hydroxyapatite coating to enduring fixation? Will unresorbed or dislodged hydroxyapatite particles cause adverse tissue reactions? Retrieval studies of clinically well-functioning acetabular components should help to answer these questions. METHODS: We examined six clinically successful hydroxyapatite-coated cementless acetabular components that were retrieved at autopsy between 3.3 and 6.6 years after implantation. All components were of the same design. The prostheses and the surrounding bone were prepared for qualitative histological and quantitative histomorphometric analysis. The percentage of bone growth onto the implant, the relative bone area around the implant, the extent of residual hydroxyapatite coating, and the coating thickness were measured. RESULTS: All of the cups showed bone ongrowth, with a mean bone-implant contact (and standard deviation) of 36.5% +/- 13.5%. The contact area was the same in all three zones delineated by DeLee and Charnley. The extent and thickness of the hydroxyapatite layer were much reduced in the specimens from older patients and in those associated with a longer duration of implantation. Degradation of the hydroxyapatite coating by osteoclasts was observed. We did not observe loose hydroxyapatite granules far from the coating, nor did we note any adverse tissue reaction to these granules. In contrast, polyethylene debris was noted in approximately half of the empty screw-holes. CONCLUSIONS: Cell-mediated hydroxyapatite resorption seems to be the main reason for loss of hydroxyapatite coating. The area of bone ongrowth was within a certain range (20% to 50%) of the measured surfaces, and it was independent of the amount of hydroxyapatite residue. The hydroxyapatite coating showed a slow rate of resorption with time, without any adverse tissue reactions.