Hybrid alumina total hip arthroplasty using a press-fit metal-backed socket in patients younger than 55 years. A six- to 11-year evaluation

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point. The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris.     

Long-term results of alumina-on-alumina hip arthroplasty for osteonecrosis

Alumina-on-alumina bearings in THR may, in theory, provide an effective answer to osteolysis in young patients with ON of the femoral head. The purpose of this retrospective study was to report the long-term results of a series of 52 consecutive alumina THAs (41 patients) done for ON. The mean age of the patients at surgery was 41 years (range, 22-79 years). Cemented femoral stems with a 32-mm alumina head were used. Plain alumina cups were used and were either cemented (39 hips) or press-fit (13 hips). No patients were lost to followup. Sixteen hips have been revised. Aseptic loosening of the socket was the main cause of failure. At an average 16-year followup (range, 11-23.65 years), 26 hips were rated excellent and one hip was rated good. No osteolysis was observed and wear was undetectable. If revision for aseptic loosening was the end point, the rate of survival was 88.5% at 10 years for the socket and 100% at 10 years for the stem. With the alumina-on-alumina hip replacement done for ON, absence of osteolysis can be expected for as many as 24 years after the operation. New methods of socket fixation now are being explored.     

Press-fit metal-backed alumina sockets: a minimum 5-year followup study

Two hundred thirty-four consecutive alumina-on-alumina hip replacements using a press-fit metal-backed socket, performed on 214 patients (98 women, 116 men) have been reviewed. These included 201 primary procedures and 33 revision procedures. The median age of the patients at the time of surgery was 62 years (range, 21-83 years). Fourteen patients (16 hips) died from unrelated causes. Eleven patients (11 hips) underwent a total hip arthroplasty revision for recurrent dislocation (one hip), deep infection (two hips), fracture of alumina femoral head (one hip), persistent hip pain (one hip) and aseptic loosening (six hips). The survival rate after 9 years was 93.4% when revision of the prosthesis was considered the end point, and 97.4% if revision of the prosthesis for aseptic loosening was considered the end point. Results were assessed in the surviving patients with a minimal 5-year followup (170 patients, 184 hips). At the median followup of 7.8 years, the average Merle d'Aubigné and Postel score had improved from 11.9- to 17.7. Results were graded as excellent in 148 hips (80.5%), very good in 31 hips (17%), good in two hips (1%), and fair in three hips (1.5%). Radiologic data were documented for 134 patients (143 hips). Three sockets (2%) had a complete and nonprogressive radiolucent line less than 1-mm thick, one stem (0.7%) had lucencies involving five zones, and two stems (1.4%) had isolated femoral osteolysis. Neither component migration nor acetabular osteolysis were detected. A press-fit metal-backed socket may offer a good solution for alumina socket fixation when combined with a careful surgical technique of implantation.     

Alumina-on-alumina total hip arthroplasty: a minimum 18.5-year follow-up study.

BACKGROUND: The purpose of this retrospective study was to report the results, after a minimum of 18.5 years of follow-up, in a consecutive series of total hip arthroplasties performed with an alumina-on-alumina combination. METHODS: One hundred and eighteen consecutive total hip arthroplasties were performed in 106 patients between 1979 and 1980. The prostheses combined a 32-mm alumina head and an all-alumina socket. Both components were cemented in eighty-five hips, both components were implanted without cement in twenty-nine, and only the stem was cemented in four. The mean age of the patients at the time of the index arthroplasty was 62.2 years (range, thirty-two to eighty-nine years). RESULTS: At the 18.5 to 20.5-year follow-up evaluation, forty-five patients (fifty-one hips) were alive and had not had a revision, twenty-five patients (twenty-five hips) had undergone revision of one or both components, twenty-seven patients (thirty hips) had died, and nine patients (twelve hips) had been lost to follow-up. The mean Merle d'Aubigné hip score (and standard deviation) was 16.2 +/- 1.8 points at the latest follow-up evaluation. The rate of survival at twenty years, with revision for any reason as the end-point, was 85.6% for the cementless cups compared with 61.2% for the cemented cups and 84.9% for the cementless stems compared with 87.3% for the cemented stems. Wear of the prosthetic components was undetectable on plain radiographs. Periprosthetic cystic or scalloped lesions requiring the use of allograft bone during revision were present in three of the twenty-five revised hips. In addition, seven hips had moderate acetabular osteolysis treated with a 4-mm-larger cup. No fracture of the alumina socket or head was recorded. The mean acetabular wear rate in this series was <0.025 mm/yr. CONCLUSION: With the alumina-on-alumina total hip arthroplasty, minimal wear rates and limited osteolysis can be expected up to twenty years after the operation, provided that sound acetabular component fixation is obtained.     

Cementless bulk alumina socket: preliminary results at 6 years.

To avoid polyethylene wear observed in total hip replacement, an alumina-alumina combination has been used since 1977. The aim of this study is to report the results of a hybrid alumina-alumina total hip arthroplasty with a cementless press-fit bulk alumina socket and a cemented titanium alloy stem in 55 patients (62 hips) operated on between 1982 and 1990. The bearing surfaces were a 32-mm alumina head articulating within the alumina socket. Four failures occurred: 3 aseptic loosenings of the socket and 1 femoral head fracture. Considering aseptic loosening as the endpoint, the survival rate was 93.2% after 6 years. At a mean of 72.1 months' follow-up, 92.4% of the surviving hips were graded as very good or good using the Merle d'Aubigné-Postel hip score. Radiolucent lines were observed on the acetabular side in 68.1 of the hips. The future of this interface, which is probably fibrous, remains questionable. With the exception of 1 femoral head fracture, all revisions were related to failure of the bony fixation of the socket, and no problem was encountered related to the alumina-alumina friction coupling. Alumina sockets with other types of cementless fixation have therefore been designed and are presently under clinical investigation.     

Alumina Inlay Failure in Cemented Polyethylene-backed Total Hip Arthroplasty

Alumina-on-alumina bearings for THA have markedly improved in mechanical properties through advances in technology; however, alumina fracture is still a concern. We retrospectively reviewed 77 patients (82 hips) with cemented alumina-on-alumina THAs to identify factors relating to alumina failure. The mean age of the patients at surgery was 63 years. The prostheses had a cemented polyethylene-backed acetabular component with an alumina inlay and a 28-mm alumina head. Revision surgery was performed because of alumina inlay failure in four hips (three fractures and one dissociation; 5.6%), deep infection in two, and recurrent dislocation in one. The 8-year survival rate was 90.7% with revision for any reason and 94.4% with revision for alumina failure as the end point. There were no differences in age, body mass index, gender, mobility, function, abduction angle, or size of component among the four hips with alumina failure and the remaining 68 hips without it; however, radiolucent lines in the sockets were more apparent in four cases with alumina inlay failure. This alumina-on-alumina THA thus yielded unsatisfactory medium-term results because we observed a high rate of catastrophic alumina inlay failure.     

Weber rotation total hip replacement: a prospective 5- to 20-year followup study

Between 1974 and 1989, 315 primary total hip replacements (274 patients) were done using the cemented Weber Rotation prosthesis and standardized operative technique, which was modified for the stem in 1978. After the first postoperative year, all patients had routine clinical and radiologic examinations at 2-year intervals. Twenty-one patients (22 hips) were lost to followup. At the most recent followup, 30 of 293 hips (253 patients) had been revised: 24 hips for aseptic loosening, five hips for infection, and one hip for a femoral fracture. Survivorship analyses with revision for aseptic loosening as an end point for the 315 hips showed 93% and 78% survival after 10 and 15 years, respectively. Separate survival analyses for the socket showed 99% and 89% survival after 10 and 15 years, respectively. The stem had a survival of 94% and 81%, respectively, during the same time. Survival at 15 years with radiologic evidence of loosening as an end point was 85% for the socket and 72% for the stem. The cementing technique and the design of the acetabular component significantly influenced the rate of loosening. Survivorship analyses with revision for aseptic loosening of the socket, using a modified second generation cementing technique and a hemispheric socket, showed 100% survival after 10 years and 98% after 13 years.     

Cementless hemispheric porous-coated sockets implanted with press-fit technique without screws: average ten-year follow-up

BACKGROUND: Press-fit implantation of a porous-coated hemispheric acetabular component without screws is an option for primary total hip replacement. The purpose of the present study was to evaluate the results of this technique after an average duration of follow-up of ten years to determine if there was any loss of fixation or increase in osteolysis over time. METHODS: From June 1988 to November 1990, 132 primary total hip replacements were performed with a porous-coated socket that was implanted with use of a press-fit technique. Twenty-two hips were excluded because the patient had died or had been lost to follow-up, leaving 110 hips (103 patients) available for inclusion in the study after an average duration of follow-up of 10.2 +/- 1.0 years. The average age of the patients at the time of operation was 60.7 years (range, 23.7 to 86.2 years). Radiographs were evaluated with regard to initial gaps, radiolucent lines, migration, polyethylene wear, and osteolysis. Kaplan-Meier survivorship analysis was performed to calculate the rate of survival of the acetabular component. RESULTS: One hip (0.9%) had revision of the socket because of aseptic loosening, and four hips (4%) had revision of a stable socket. With the numbers available, the presence of gaps on the initial postoperative radiographs was not associated with the occurrence of radiolucent lines (p = 0.039). Pelvic osteolysis was seen in four hips, with an average time to radiographic appearance of six years. Increased wear was directly related to an abduction angle of >40 degrees. The twelve-year survival rate was 99.1% with revision because of failure of fixation of the metal shell as the end point, 95.3% with revision for any reason as the end point, and 79.6% with exchange of the liner as the end point. CONCLUSIONS: The fixation of this press-fit socket did not deteriorate over time and was associated with a low rate of osteolysis. The most common reasons for reoperation were wear and dissociation of the polyethylene insert.     

Long-term survivorship of cemented all-polyethylene acetabular components in patients > 75 years of age

Between 1974 and 1982, 132 consecutive hips in 112 patients >75 years of age were treated with primary total hip arthroplasty for osteoarthritis using a cemented all-polyethylene T28 socket and cemented T28 or TR28 stem with a 28-mm head size. At the time of review, 94 patients (110 hips [83%]) had died and 18 patients (22 hips [17%]) were still living (mean age at follow-up, 93 years). Five hips (5 patients) were lost to follow-up. Clinical follow-up averaged 8.9 years for the entire group and 14.6 years for patients still living. Only 2 acetabular components have been revised (1 for recurrent dislocation, 1 for infection). No acetabular component has required revision for aseptic loosening. Survivorship free of acetabular revision for aseptic loosening at 10 years was 100%; free of symptomatic acetabular loosening, 97.4% (95% confidence interval, 91.8-100%); and free of acetabular loosening, 95.9% (95% confidence interval, 89.7-100%). The commonest complication was postoperative hip dislocation, which occurred in 11 hips (8.7%) and which required reoperation in 2 hips. Cemented acetabular components implanted in patients >75 years of age with a diagnosis of osteoarthritis showed a high rate of survivorship free of revision and free of symptomatic aseptic loosening.     

Prevention of wear and osteolysis: alumina-on-alumina bearing.

Alumina-on-alumina bearings in total hip replacement have been used for 30 years. Excellent tribologic properties and extra low debris generation could, in theory, provide an answer to osteolysis. A review of the authors' experience with alumina-on-alumina bearings showed that, except in a few bearings that had been loose for a long time, osteolysis was not a problem. Although the cemented titanium stem and the alumina-on-alumina couple were not a problem, fixation of the socket had to be improved. To improve the socket fixation system and to avoid the use of a cemented titanium stem that may have created problems in the long-term, a new design was introduced in 1997. The current authors present the preliminary results of the first 96 hips with cementless fully-coated hydroxyapatite titanium alloy stems and sockets, 32-mm alumina femoral head, and alumina liner, both held with a Morse taper. Ninety-six consecutive hips in 89 patients (57 males, 32 females) with a median age of 46 years (range, 14-72 years) were analyzed. One socket was revised at 4 months because of poor primary stability in a patient with a severe acetabular fracture. One patient experienced a traumatic fracture of the implanted femur 3 weeks after surgery. The mean followup was 16 months (range, 4-38 months). One patient died from rupture of an aneurysm. Ninety-three hips in 86 patients were assessed regarding the clinical and radiologic ratings. Two patients (two hips) were interviewed by telephone. The Merle d'Aubigné rating system was 18 in 65 hips (59 patients), 17 in 25 hips (25 patients), and 16 in three hips (three patients) mainly related to a previous disability including limp, sciatic palsy, or stiffness. Examination of 93 available radiographs revealed no ostelolysis, no radiolucent lines at the last examination, and no subsidence. The level of excellent results, even in this young population, and lack of osteolysis and wear are encouraging, even if the followup is too short to allow any conclusions to be made.     

Poor outcome of 44 cemented total hip arthroplasties with alumina ceramic heads: clinical evaluation and retrieval analysis after 10-16 years.

We evaluated the long-term results of cemented total hip arthroplasty with alumina ceramic heads in 39 patients (44 hips) from 1981 to 1985. The study comprised 8 men (8 hips) and 31 women (36 hips). Their mean age was 54 (37-76) years and mean weight 52 (34-93) kg. The preoperative diagnoses were osteoarthrosis in 34 patients (38 hips), rheumatoid arthritis in 3 (4 hips) and idiopathic osteonecrosis of the femoral head in 2 (2 hips). The mean duration of follow-up was 13 (10-16) years. At this time, 6 cases had been revised because of aseptic loosening (5 hips showed loosening of both components and 1 acetabular loosening alone). Kaplan-Meier survivorship analysis with radiographic loosening as end-point showed 10-year survival rates of 75% for the acetabular component and 86% for the femoral. The mean linear wear rate of polyethylene was 0.10 mm/year radiographically--i.e., about the same as reported for many metal to polyethylene bearings. 5 alumina ceramic heads were retrieved and showed excellent surface roughness and roundness without scratches. However, debris stuck to the gaps was detected. The debris may act as third-bodies and affect polyethylene wear.     

Poor outcome of 44 cemented total hip arthroplasties with alumina ceramic heads: Clinical evaluation and retrieval analysis after 10-16 years

We evaluated the long-term results of cemented total hip arthroplasty with alumina ceramic heads in 39 patients (44 hips) from 1981 to 1985. The study comprised 8 men (8 hips) and 31 women (36 hips). Their mean age was 54 (37-76) years and mean weight 52 (34-93) kg. The preoperative diagnoses were osteoarthrosis in 34 patients (38 hips), rheumatoid arthritis in 3 (4 hips) and idiopathic osteonecrosis of the femoral head in 2 (2 hips). The mean duration of follow-up was 13 (10-16) years. At this time, 6 cases had been revised because of aseptic loosening (5 hips showed loosening of both components and 1 acetabular loosening alone). Kaplan-Meier survivorship analysis with radiographic loosening as end-point showed 10-year survival rates of 75% for the acetabular component and 86% for the femoral. The mean linear wear rate of polyethylene was 0.10 mm/year radiographically--i.e., about the same as reported for many metal to polyethylene bearings. 5 alumina ceramic heads were retrieved and showed excellent surface roughness and roundness without scratches. However, debris stuck to the gaps was detected. The debris may act as third-bodies and affect polyethylene wear.     

Poor outcome of 44 cemented total hip arthroplasties with alumina ceramic heads: Clinical evaluation and retrieval analysis after 10-16 years

We evaluated the long-term results of cemented total hip arthroplasty with alumina ceramic heads in 39 patients (44 hips) from 1981 to 1985. The study comprised 8 men (8 hips) and 31 women (36 hips). Their mean age was 54 (37-76) years and mean weight 52 (34-93) kg. The preoperative diagnoses were osteoarthrosis in 34 patients (38 hips), rheumatoid arthritis in 3 (4 hips) and idiopathic osteonecrosis of the femoral head in 2 (2 hips). The mean duration of follow-up was 13 (10-16) years. At this time, 6 cases had been revised because of aseptic loosening (5 hips showed loosening of both components and 1 acetabular loosening alone). Kaplan-Meier survivorship analysis with radiographic loosening as end-point showed 10-year survival rates of 75% for the acetabular component and 86% for the femoral. The mean linear wear rate of polyethylene was 0.10 mm/year radiographically--i.e., about the same as reported for many metal to polyethylene bearings. 5 alumina ceramic heads were retrieved and showed excellent surface roughness and roundness without scratches. However, debris stuck to the gaps was detected. The debris may act as third-bodies and affect polyethylene wear.     

10-year results of the uncemented Allofit press-fit cup in young patients

Background and purpose — Uncemented acetabular components in primary total hip arthroplasty (THA) are commonly used today, but few studies have evaluated their survival into the second decade in young and active patients. We report on a minimum 10-year follow-up of an uncemented press-fit acetabular component that is still in clinical use.

Methods — We examined the clinical and radiographic results of our first 121 consecutive cementless THAs using a cementless, grit-blasted, non-porous, titanium alloy press-fit cup (Allofit; Zimmer Inc., Warsaw, IN) without additional screw fixation in 116 patients. Mean age at surgery was 51 (21–60) years. Mean time of follow-up evaluation was 11 (10–12) years.

Results — At final follow-up, 8 patients had died (8 hips), and 1 patient (1 hip) was lost to follow-up. 3 hips in 3 patients had undergone acetabular revision, 2 for deep infection and 1 for aseptic acetabular loosening. There were no impending revisions at the most recent follow-up. We did not detect periacetabular osteolysis or loosening on plain radiographs in those hips that were evaluated radiographically (n = 90; 83% of the hips available at a minimum of 10 years). Kaplan-Meier survival analysis using revision of the acetabular component for any reason (including isolated inlay revisions) as endpoint estimated the 11-year survival rate at 98% (95% CI: 92–99).

Interpretation — Uncemented acetabular fixation using the Allofit press-fit cup without additional screws was excellent into early in the second decade in this young and active patient cohort. The rate of complications related to the liner and to osteolysis was low.     

Aseptic loosening in metal-backed acetabular components for total hip replacement. A minimum five-year follow-up

We reviewed the cases of thirty-six patients who had forty cemented total hip replacements with the Harris metal-backed acetabular component. The operations were done between 1972 and 1977, and the duration of follow-up averaged 7.6 years (range, five to 10.8 years). The average age of the patients was forty-four years (range, sixteen to sixty-two years). Aseptic loosening of the acetabular component occurred in three hips (7.5 per cent), and three more sockets were revised for other reasons. Two of the three sockets with aseptic loosening were in the fifteen patients (seventeen hips) who were forty-five years old or younger. The remaining loose cup was in one of the twenty-one patients (twenty-three hips) who were forty-six years old or older. The reduction in the rate of aseptic loosening of the socket in our series, compared with the higher rates reported in similar long-term studies in which other acetabular components were used, supports the conclusion that there is enhanced longevity of acetabular fixation when a metal-backed acetabular component is used in cemented total hip arthroplasty.     

Analysis of survivorship after total hip arthroplasty using a ceramic head

To determine the clinical efficacy of an alumina ceramic head, 119 cemented total hip arthroplasties in 97 patients using an alumina head coupled with ethylene oxide gas sterilized polyethylene were reviewed. Eighty-two patients (101 hips) with greater than 10 years followup were evaluated clinically and radiographically (range, 10-17.6 years), and 97 patients (119 hips) were evaluated for survivorship analysis (range, 0.6-17.6 years). The average functional hip scores according to Merle d'Aubigné and Postel improved from 8.6 preoperatively to 15.0 at the final followup, and 57 patients (64 hips) had no pain. The average polyethylene wear rate was 0.15 mm/year (range, 0.04-0.34 mm/year). Patients with polyethylene wear greater than 3 mm showed significantly higher rates of acetabular loosening. Fifteen-year survival rates (with 95% confidence intervals) with radiographic evidence of aseptic loosening as the end point were 46.8% +/- 13.4% in acetabular components and 91.9% +/- 6.6% in femoral components. Fifteen-year survival rates of hip arthroplasties with revision because of aseptic loosening as the end point were 75.3% +/- 10.2% and 97.9% +/- 3.0%, respectively. Results of the current study suggest that using an alumina head instead of a metal head may not be beneficial when coupled with ethylene oxide gas sterilized polyethylene.     

High survival in young patients using a second generation uncemented total hip replacement

Purpose

Whilst excellent long-term results with contemporary uncemented stems have been reported for total hip arthroplasty in young patients, the survival rates for the whole reconstruction are often compromised by high failure rates on the acetabular site due to peri-acetabular osteolysis and accelerated wear.

Methods

In patients 60 years old or younger, we retrospectively reviewed the results at a minimum of ten years of 89 consecutive uncemented total hip replacements in 88 patients using the press-fit Fitmore acetabular component in combination with the CLS Spotorno stem and a 28-mm Metasul metal-on-metal articulation or a 28-mm alumina ceramic on conventional polyethylene bearing. The mean age at the time of surgery was 49 years (range, 25–60). The mean clinical and radiological follow-up was 12 years (range, 10–15).

Results

Six patients (six hips) died and two patients (two hips) were lost to follow-up. Five hips were revised: one for deep infection, one for peri-prosthetic femoral fracture, and one for aseptic stem loosening. In two hips an isolated revision of the acetabular liner was performed (one for recurrent dislocation and one for unexplained pain). No revision was performed for accelerated wear, osteolysis or aseptic loosening of the acetabular shell. We could not detect peri-acetabular osteolysis visible on plain radiographs in those hips evaluated radiographically. The Kaplan-Meier survival with revision for any reason as the endpoint was 94% (95% confidence interval, 86–97) at 12 years.

Conclusions

The survival rates and the radiological outcomes with this implant combination in this young and active patient group are encouraging when compared to the results reported for other uncemented cups in this age group.     

Cementless total hip arthroplasty with ceramic-on-ceramic bearing in patients younger than 45 years with femoral-head osteonecrosis

Despite improvements in the quality of alumina ceramics, osteolysis has been reported anecdotally after total hip arthroplasty (THA) with use of a contemporary alumina-on-alumina ceramic bearing. The purpose of this study was to evaluate the clinical and radiographic outcomes of THA using alumina-on-alumina ceramic bearing and to determine osteolysis using radiographs and computed tomographic (CT) scans in young patients. Consecutive primary cementless THA using alumina-on-alumina ceramic bearing were performed in 64 patients (93 hips) who were younger than 45 years of age with femoral-head osteonecrosis. There were 55 men (84 hips) and nine women (nine hips). Average age was 38.2 (range 24–45) years. Average follow-up was 11.1 (range 10–13) years. Preoperative Harris Hip Score was 52.9 (range 22–58) points, which improved to 96 (range 85−100) points at the final follow-up examination. Two of 93 hips (2%) had clicking or squeaking sound. No hip had revision or aseptic loosening. Radiographs and CT scans demonstrated that no acetabular or femoral osteolysis was detected in any hip at the latest follow-up. Contemporary cementless acetabular and femoral components with alumina-on-alumina ceramic bearing couples function well with no osteolysis at a ten year minimum and average of 11.1-year follow-up in this series of young patients with femoral-head osteonecrosis.     

Revision Total Hip Arthroplasty Using an Alumina-On-Alumina Bearing Surface in Patients With Osteolysis

We evaluated the outcomes of 64 consecutive revision total hip arthroplasties with an alumina-on-alumina bearing surface in 61 patients with osteolysis. No implants had been rerevised nor was osteolysis detected at a mean of 9.8 years (range, 7.0-13.1 years) postoperatively. There was 1 case of stem loosening but no cup loosening or alumina bearing fractures. Two surgical procedures were performed for an infection in 1 patient. Three dislocations occurred in 3 hips; all were treated with closed reduction and abduction bracing for 3 months. No further dislocations occurred. With any reoperation or radiographic evidence of osteolysis or loosening as the end point, the 7-year survival rate was 96.9% (95% confidence interval, 90.8%-100%). The alumina-on-alumina bearing surfaces used for revision total hip arthroplasty in patients with osteolysis were found to produce encouraging clinical results and implant survival rates at a minimum of 7 years postoperatively.     

Survivorship analysis at 15 years of cemented press-fit condylar total knee arthroplasty

We performed a survival analysis on 354 cemented primary press-fit condylar total knee arthroplasties in 277 patients with prospective follow-up (mean, 8.8 years; range, 0.3-16.9 years). The number of patients alive reaching 15 years at follow-up for survival analysis was 15. The cumulative survival rate at 15 years was 81.7% (95% confidence interval, 72.1%-88.5%), using revision for all causes as our end point. Indications for revision in our patient group were aseptic loosening 4.5%, infection 2.3%, and exchange of polyethylene insert 1.1%. Our results indicate that the cemented press-fit condylar total knee arthroplasty has a good long-term survival, at 15 years, based on revision as the end point.