Charnley total hip arthroplasty in patients less than fifty years old. A twenty to twenty-five-year follow-up note

We evaluated the results twenty to twenty-five years after ninety-three consecutive, nonselected Charnley total hip arthroplasties performed with cement by the senior one of us in sixty-nine patients who were less than fifty years old at the time of the procedure. Seventy of the seventy-two hips in the living patients were followed radiographically for at least twenty years. Twenty-seven hips (29 per cent) had a revision or a resection of the prosthesis during the follow-up period. The revision or the resection was performed because of aseptic loosening in twenty-one hips (23 per cent), infection in four (4 per cent), dislocation in one (1 per cent), and fracture of the femur in one. Eighteen acetabular components (19 per cent) and five femoral components (5 per cent) were revised because of aseptic loosening, and an additional fourteen acetabular components (15 per cent) and seven femoral components (8 per cent) demonstrated definite or probable radiographic loosening. The present study demonstrates the long-term durability of total hip arthroplasty performed with cement in an active population of patients. The fixation of the femoral component was found to perform better than that of the acetabular component at twenty to twenty-five years after the procedure.     

Total hip arthroplasty with cement in patients who have rheumatoid arthritis. A minimum ten-year follow-up study

One hundred and six consecutive total hip arthroplasties with cement were performed by one surgeon, at least ten years before the time of the present clinical and radiographic review, in seventy-five patients who had adult-onset rheumatoid arthritis. Two patients (three hips) were lost to follow-up. Seven (7 per cent) of the remaining 103 hips were revised. The revisions were performed because of infection (three hips), dislocation (two hips), or aseptic loosening (two hips). Of the ninety-eight hips that were not lost to follow-up or revised because of infection or dislocation, eight (8 per cent) had radiographic loosening of the acetabular component and two (2 per cent) had radiographic loosening of the femoral component. Although the prevalence of radiographic loosening of the acetabular component was four times greater than the prevalence of radiographic loosening of the femoral component, the prevalence of revision because of aseptic loosening of the acetabular component was identical to that for the femoral component (one component each). These results compared favorably with those of total hip arthroplasty with cement, performed by the same surgeon, for the treatment of other diagnoses. Loosening of the acetabular component was significantly associated with a younger age at the time of the index operation (p = 0.03) and with acetabular osteolysis (p = 0.0006). Of forty-eight hips in thirty-two patients who survived for at least ten years, 96 per cent (forty-six hips) were considered by the patients to have a satisfactory result. At the time of the latest follow-up, twenty-four (75 per cent) of the patients had no pain in the hip. Although eighteen patients (56 per cent) could walk without support at a minimum of ten years after the operation, we found that the functional results for patients who had rheumatoid arthritis were inferior to those observed for patients who had had a total hip arthroplasty with cement, performed by the same surgeon, for the treatment of other diagnoses.     

Total hip arthroplasty with use of second-generation cementing techniques. An eighteen-year-average follow-up study

In this report, we present the results of a further follow-up of a series of 140 consecutive patients (161 hips) who had had a primary total hip arthroplasty with insertion of a bead-blasted monoblock femoral component with use of so-called second-generation cementing techniques. The average age of the patients at the time of the arthroplasty was sixty-one years (range, twenty-one to eighty-five years). Sixty-seven patients (seventy-seven hips) died less than seventeen years after the index operation. The remaining seventy-three patients (eighty-four hips) were followed for an average of eighteen years (range, seventeen to twenty years). No patient was lost to follow-up. In the entire group of 161 hips, over the twenty-year span of the study, eight femoral components (5 percent) and twenty-eight acetabular components (17 percent) had been revised because of aseptic loosening. Of the seventy-seven hips in the sixty-seven patients who died, four had been revised because of aseptic loosening of the acetabular component only; one, because of aseptic loosening of the femoral component only; and one, because of aseptic loosening of both components. Of the eighty-four hips in the seventy-three patients who were alive at least seventeen years after the index arthroplasty, twenty-four hips (29 percent) in twenty-one patients had had revision of one or both components for any reason. Twenty-three acetabular components (27 percent) and six femoral components (7 percent) had been revised because of aseptic loosening. An additional two hips (2 percent) in two patients were loose according to radiographic criteria but had not been revised. Of the sixty-five all-polyethylene acetabular components that had been inserted with cement and were in patients who were alive at least seventeen years postoperatively, fifteen (23 percent) had been revised because of aseptic loosening. An additional seventeen cups (26 percent) were loose according to radiographic criteria. Thus, a total of thirty-two cups (49 percent) had been revised because of loosening or were loose but had not been revised at the time of the latest follow-up. The femoral components that had been inserted with use of second-generation cementing techniques fared better than did the acetabular components that had been inserted with these techniques during the same time-period. We found that assessment of all postoperative radiographs rather than only those that had been made immediately postoperatively increased the accuracy of the grading of the cement around the femoral component. Subsequent radiographs frequently had been made at different projections, which revealed new findings, consisting primarily of previously undetected voids, areas of thin cement, and defects in the cement mantle. Thus, we now use all available radiographs to determine the grade of the cement.     

Failure of the Mecring screw-ring acetabular component in total hip arthroplasty. A three to seven-year follow-up study

We prospectively studied the results of 411 consecutive total hip arthroplasties with a Mecring screw-ring acetabular component inserted without cement combined with a Stanmore femoral stem inserted with cement. The duration of follow-up ranged from three to seven years (mean, four years and six months). Three hundred and thirty-one patients (378 hips) were available for physical examination and had a complete set of radiographs. The clinical result was good or excellent for 82 per cent (309) of the 378 hips. However, the rate of radiographic loosening of the acetabular component, as evidenced by migration at the most recent follow-up examination, was alarmingly high: 25 per cent (ninety-five) of the 378 hips. In general, these patients did not have serious clinical symptoms. The cups in women migrated significantly more often (p = 0.003) than those in men. Migration was also more frequent in patients who were less than fifty-one years old and in patients in whom the index procedure was a revision arthroplasty, but these differences were not significant. Twenty-one (6 per cent) of the acetabular cups were revised for aseptic loosening. The high rate of radiographic loosening has led us to abandon the use of the Mecring screw-ring acetabular component.     

A femoral component inserted without cement in total hip arthroplasty. A study of the Tri-Lock component with an average ten-year duration of follow-up

Seventy-four total hip arthroplasties in sixty-six patients were performed, between 1983 and 1986, with use of a Tri-Lock femoral component inserted without cement. This tapered cobalt-chromium component has a fixed head and a circumferential proximal porous coating. Follow-up was conducted with use of a questionnaire, physical examination, and radiographic analysis. At the time of the latest follow-up, fifteen patients (eighteen hips) had died, three patients (four hips) had been lost to follow-up, and one patient (one hip) had refused to participate in the follow-up study; however, the status of fifteen hips at the time of death could be verified. Thus, clinical follow-up data were available for sixty-six of the original seventy-four hips. The average age at the time of the operation was sixty-two years (range, seventeen to eighty-four years), and the average interval between the operation and the latest follow-up evaluation was 10.0 years (range, 8.3 to 11.6 years). The Harris hip score was determined for forty-three hips (forty-one patients) in which the prosthesis was in situ at the time of the latest follow-up. The score was good for thirteen hips and excellent for twenty-eight, so the rate of clinical success was 95 per cent. Two patients had a fair result. One of them had persistent pain and the other had limited motion, but neither had radiographic evidence of loosening of the femoral or acetabular component. All forty-one patients were satisfied with the result. The probability (with standard error) of survival of the femoral component at ten years, with revision as the end point, was 0.95 +/- 0.03. The rate of revision of the femoral component because of aseptic loosening was one (2 per cent) of sixty-six. The overall rate of aseptic loosening of the femoral component in the hips that were followed radiographically was two (4 per cent) of forty-seven. Only one (2 per cent) of the forty-seven acetabular cups had evidence of aseptic loosening. There was no radiographic evidence of distal osteolysis around the prostheses that were well fixed. Proximal osteolysis was present in five (11 per cent) of forty-seven hips, but none of the lesions compromised the stability of the prosthesis or the bone and there were no associated fractures. At an average of ten years postoperatively, the Tri-Lock femoral component functioned well overall and patient satisfaction was high.     

Acetabular and femoral fixation 15 years after cemented total hip surgery

Total hip arthroplasty in patients younger than 51 years of age remains controversial. The authors report results in 47 hips in 40 patients at an average followup of 15 years. Second generation femoral cementing techniques were used. Special attention was given to studying the differences between the outcome of acetabular versus femoral fixation. The patient group included 11 in whom custom components were used and 13 who had structural autografts for severe acetabular dysplasia. One femoral component and 10 acetabular components were revised for aseptic loosening. After 15 years, improved cementing techniques produced a marked reduction in the rate of femoral aseptic loosening. Loss of fixation of cemented acetabular components was common.     

Radiotherapy for elderly patients

Fifty-seven revision total hip arthroplasties in fifty-six patients were performed with a Harris-Galante porous-coated acetabular component by one surgeon, and the patients were followed prospectively for a mean of seven years (range, five to twelve years). A trochanteric osteotomy was performed in forty hips, and a posterior approach with an extended anterior capsulectomy was used in the other seventeen. The acetabular defect was classified as segmental in seven hips, cavitary in twenty-three, and combined in twenty-one; six hips had no notable defect. A bulk allograft was used in eleven hips, and morseled cancellous-bone allograft or autogenous graft was used in thirty-four hips; twelve hips did not have bone-grafting. Both the femoral and the acetabular component were revised in forty-five hips, and only the acetabular component was revised in twelve. Thirty-nine hips (68 per cent) had a good or excellent clinical result according to the Harris hip score. The acetabular component was well fixed in the fourteen hips that had a fair result and the four hips that had a poor result. The acetabular component was considered to have migrated if there was a change in the angle of the cup of 5 degrees or more or a change in the horizontal or vertical position of the cup of more than three millimeters. Despite varying degrees of bone loss, no acetabular component had radiographic evidence of loosening at the latest follow-up examination. No component was revised and no revisions were scheduled. One hip was debrided for a late metastatic infection, but the component was well fixed and was not revised. There were no complications related to the use of screws for fixation. These mid-term results confirm the early success of acetabular revisions performed with fixation of a titanium fiber-metal-coated hemispherical component with multiple screws and no cement.     

Ceramic endoprosthesis in total hip arthroplasty

Aluminia-on-aluminia hip prosthesis with titanium alloy stem was used in 255 cases, for 143 patients with cemented acetabular cup and 112 with an uncemented screw cup. The average age of the patients was 62 years. Of the patients, 35 were treated bilaterally. The indication for surgery was osteoarthritis in 186 cases, fractures and nonunions of the hip joint in 34 cases, and congenital dislocations of the hip joint in 16 cases. Previous surgery of the hip joint was recorded for 43 cases. All procedures were primary arthroplasties. Only personal clinical examinations together with radiographic studies were accepted as clinical data. Three patients failed to show up for routine follow-up evaluation and these were excluded from the series. Revision operation was classified as failure. The indications for revision were aseptic loosening, late infection, and fracture of the acrylic cement resulting in loosening of the acetabular or femoral component. The acetabular component was cemented in 143 patients and the mean follow-up period for these patients was 6.7 years (range, 1-12 years). In this series, a revision operation was undertaken for 16 patients (11%). In 12 cases, broken acrylic cement resulted in acetabular aseptic loosening. In the series of 112 patients with uncemented titanium screw cup, the mean follow-up period was 3.6 years (range, 1-7 years) and a revision operation was undertaken in seven cases (7%). In two, the indication was late infection; in one, technical failure; and in two, progression of Pigmented villonodular synovitis. Acetabular aseptic loosening resulted in revision in only two cases. With cementless acetabular component bone transplantation is indicated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute cocaine results in rapid rises in intracellular free calcium concentration in canine cerebral vascular smooth muscle cells: possible relation to etiology of stroke

We report the outcome of 177 consecutive primary Charnley total hip arthroplasties inserted with Boneloc cement between November 1991 and November 1993. There were 107 women and 70 men. The mean age at the time of the operation was 71 years. 11 patients (13 hips) died during the follow-up period and 3 patients were too weak to attend a follow-up examination. Of the 161 remaining hips, 4 had been revised because of deep infection. The mean follow-up time for the remaining 157 hips was 2 (0.5-3) years. 24 hips had been revised and 6 are waiting for revision because of stem loosening. Of the remaining 127 hips, 72 showed radiographic signs of stem loosening and 2 hips were probably loose. Osteolysis was seen around the femoral component in 56 hips.     

Extensively coated femoral components in young patients

A review of 174 hips in 154 patients younger than 50 years of age who underwent primary total hip arthroplasty with a cementless acetabular component and an extensively coated femoral component done by one surgeon was performed to determine whether this method of fixation improves the results of previously reported comparable series using different methods of fixation. The average age was 37.6 years. The average followup was 8.3 years (range, 2-13 years). Eighty-eight hips had at least 10 years followup. Sixteen (9%) hips had severe stress shielding. There were 13 (7.5%) acetabular failures. Of 144 porous coated cups, three were revised for wear and one for dislocation. Another was revised 11 years postoperatively for late loosening secondary to catastrophic acetabular lysis. Excluding the bipolar and threaded components (30 hips), five (3.4%) porous coated cups were revised for failure. Of the 174 fully coated stems, 99.4% had stable fixation, 167 (96%) were ingrown, six (3.4%) had stable fibrous fixation, and one (0.6%) was unstable. Two (1.1%) femoral stems were revised. The total rate of osteolysis was 4%. Cementless extensively porous coated stems and porous coated acetabuli give excellent lasting results in young patients.     

Rationale of a flexible press fit cup in total hip replacement. 5-year followup in 280 procedures

A consecutive series of 280 total hip replacements in 261 patients using the Press Fit Cup with a minimum followup of 5 years is presented. The Press Fit Cup is a nonmodular acetabular component with a porous coating made of titanium fibers. It has one peg and is 1.5 mm oversized with biradial eccentricity. It has a flattened pole area, requires no screw fixation, and partially preserves elasticity. The mean age was 71 years for women, 70 years for men. Forty-seven patients (49 hips) died before the 5-year review, and five patients were unable to return for the followup because of physical infirmity. Two hundred eighteen patients (226 hips) were available for the clinical 5-year followup, and 208 patients (213 hips) were available for the radiographic followup. No intraoperative fracture of the acetabulum occurred; four hips dislocated; 94% clinically were rated as excellent or good. One hip in a patient with rheumatoid arthritis had to be revised for aseptic loosening of the cup and nine femoral stems had to be revised. No migration of the cup could be measured. There was no osteolysis seen around the cup. In six cases a radiolucent line was seen in Zone 1, and in eight hips in Zone 3. There was one hip with a continuous radiolucent line which was considered radiographically loose.     

Long-term results of total hip replacement in young patients who had ankylosing spondylitis. Eighteen to thirty-year results with survivorship analysis

We determined the long-term results of total hip replacement in a series of young patients who had ankylosing spondylitis. Between 1966 and 1978, forty-three Charnley low-friction arthroplasties were performed in twenty-four patients who had an average age of 28.8 years (range, nineteen to thirty-nine years) at the time of the operation. There were seventeen men and seven women. The average duration of follow-up for the series was 22.7 years (range, one month [a perioperative death] to 30.3 years). Four patients (seven hips) had died an average of 12.6 years (range, one month to 18.7 years) after the operation. The twenty surviving patients had clinical and radiographic follow-up until the time of writing or until both of the original components had been revised. All patients had substantial relief of pain and improvement of function and the range of motion of the joint. Twenty-one patients (88 per cent; thirty-nine hips) were completely free of pain (6 points, according to the scale of Merle d'Aubigne and Postel), and the remainder had only slight discomfort (5 points). Ten acetabular components and one femoral component were revised because of aseptic loosening, and one patient had a revision of both components because of late deep infection. Three additional femoral components were revised during a revision operation for a loose acetabular component. Although the femoral components were not loose, they had been in place for more than ten years and it was thought likely that the bearing surface was damaged. The average time to revision was 13.3 years (range, 4.0 to 20.3 years). At an average of 22.7 years, thirty-eight (88 per cent) of the original femoral components and thirty-two (74 per cent) of the original acetabular components remained in situ. The average annual rate of acetabular wear was 0.12 millimeter for the entire series. Only six hips (14 per cent) had minor heterotopic ossification, and none of the hips had clinically important ossification (class III or IV according to the system of Brooker et al.). To our knowledge, the present report describes the largest series of total hip arthroplasties, with the longest duration of follow-up, in young patients who had ankylosing spondylitis. Survivorship analysis with use of the Kaplan-Meier method revealed that the probability of survival of the femoral component (with 95 per cent confidence intervals) was 91 per cent (83 to 99 per cent) at twenty years and 83 per cent (72 to 94 per cent) at thirty years. The probability of survival of the acetabular components was 73 per cent (61 to 84 per cent) at twenty years and 70 per cent (57 to 83 per cent) at thirty years. The probability that both components would survive was 91 per cent (82 to 100 per cent) at ten years, 73 per cent (61 to 84 per cent) at twenty years, and 70 per cent (57 to 83 per cent) at thirty years. The Charnley low-friction arthroplasty provided consistently good long-term results, with a low rate of complications and revisions, in this group of young patients.     

Porous-coated acetabular components with screw fixation. Five to ten-year results

The results of 136 consecutive primary total hip arthroplasties performed by one surgeon with the Harris-Galante-I porous-coated acetabular component were reviewed at a mean of seven years (range, five to ten years). In all hips, the outer diameter of the acetabular component was the same as the diameter of the final reamer used in the preparation of the acetabulum. However, this reamer was used only briefly at the rim of the acetabulum, and therefore the components had so-called press-fit stability. A mean of four screws (range, three to six screws) were used for additional fixation of the component. The clinical evaluation was performed with use of the Harris hip score. Standardized anteroposterior radiographs of the pelvis were assessed for migration of the component, radiolucent and radiodense lines, linear wear of the polyethylene, and osteolysis. No acetabular component had been revised for loosening and none were radiographically loose at the time of the most recent follow-up evaluation. There were no complications related to the use of the screws, and no screw had bent or broken. A non-progressive radiolucent line was seen in one acetabular zone in thirty-four hips (25 per cent) and in two acetabular zones in six hips (4 per cent). No hip had a radiolucent line in all three acetabular zones. The mean rate of linear wear of the polyethylene was 0.1 millimeter per year. There was no dissociation of the acetabular liner from the metal shell. Two hips (1 per cent) had asymptomatic osteolysis in the ischium and adjacent to the rim of the acetabular component; this was treated with grafting at the site of the lesion and exchange of the femoral head and the worn polyethylene liner. Five femoral components inserted without cement and one inserted with cement were revised because of loosening. The data suggest that, at a mean of seven years, fixation of this porous-coated component was uniformly excellent. The low prevalence of radiolucent lines and the absence of loosening are probably related, in part, to the technique of implantation. The low prevalence of polyethylene wear and pelvic osteolysis is a notable improvement compared with the results of arthroplasty with other porous-coated acetabular components. Although the results of the present study are encouraging, longer follow-up is necessary to determine the prevalence of late loosening and osteolysis.     

Total hip arthroplasty with porous-coated prostheses fixed without cement in patients who are sixty-five years of age or older

We reviewed the results of 212 total hip arthroplasties performed without cement in 203 unselected, consecutive patients who were sixty-five years of age or older. The outcome was known for 196 hips, thirty-seven of which had been followed until the death of the patient and 159 of which had been followed for a minimum of five years. A reoperation was done in 4 percent (seven) of the 196 hips. These reoperations included one revision because of loosening of the stem and five revisions of the cup. Three of the acetabular revisions were done because of fracture due to polyethylene wear; one, because of recurrent dislocation; and one, because of polyethylene wear and a fracture due to lysis. In the seventh reoperation, a cup and stem were exchanged because of infection. The probability that a hip prosthesis would survive twelve years without a reoperation was 0.92 (95 percent confidence interval, 0.85 to 0.99). We evaluated the clinical results for 152 patients who had not had a reoperation and had been followed for at least five years (mean, 8.5 years; range, five to fourteen years). Of these patients, thirteen (9 percent) had pain that limited activity: five (3 percent) had pain in the thigh (four patients) or groin (one patient), and eight (5 percent) had trochanteric pain and tenderness. One hundred and forty-four (95 percent) of the patients noted an improvement in overall function, and 149 (98 percent) reported satisfaction with the outcome. One hundred and thirty-five hips that were not revised were followed radiographically for at least five years (mean, 8.2 years; range, five to fourteen years). In this group, osteolysis was observed in three hips (2 percent); loosening of the cup, in three (2 percent); and loosening of the stem, in one (1 percent). Stress-shielding was seen on the two-year postoperative radiographs of forty-five (26 percent) of the 174 hips that were followed for at least that duration. The prevalence of osteolysis, loosening of a component, and reoperations was no greater in this subgroup than in the overall group. These results indicate that total hip arthroplasty without cement can be successful in older patients. This study also provides a reference for comparison with the results of total hip arthroplasty performed with cement and those of so-called hybrid total hip arthroplasty (an acetabular component fixed without cement and a femoral component fixed with cement) in patients who are sixty-five years of age or older.     

Proteasomal regulation of nuclear receptor corepressor-mediated repression

We analyzed the clinical results of 195 Harris Design-2 total hip replacements performed with so-called second-generation cementing techniques in 166 consecutive patients who had osteoarthrosis. The mean age of the patients at the time of the replacement was sixty-seven years and nine months (range, thirty-one to eighty-nine years). Forty-eight patients (fifty-four hips) died before the time of the latest follow-up, but the implants were apparently functioning well at the time of death. Three patients (four hips) were lost to follow-up. Five patients (five hips; 3 percent) had a revision because of aseptic loosening of the acetabular or femoral component, or both, that was related to wear-induced osteolysis. The mean Harris hip score for the 131 hips that were available at the latest follow-up examination at a mean of twelve years (range, ten to fifteen years) after the operation was 89 +/- 10 points. On the basis of the Harris hip score, seventy-six hips had an excellent result, thirty-four had a good result, fifteen had a fair result, and six had a poor result at the latest follow-up examination. Radiographically, twelve (9 percent) of the 131 acetabular components and three (2 percent) of the 131 femoral components were probably or definitely loose. At a mean of twelve years, 186 (97 percent) of 191 Harris Design-2 implants were in situ or had been in situ at the time of the patient's death.     

Survivorship analysis of cemented total hip arthroplasty acetabular components implanted with second-generation techniques

The clinical and radiographic results of primary cemented total hip arthroplasty performed by a single surgeon, with particular emphasis on the performance of acetabular components implanted with so-called second-generation cement techniques, were studied. Seventy hips with 48 metal-backed and 22 polyethylene acetabular components were followed for a mean of 9 years (range, 5-11.5 years). The clinical results were evaluated using a recognized hip score. The fixation status of the cemented acetabular component was evaluated using two methods of measuring radiolucent lines at 5 years and at the last evaluation. Acetabular component loosening was defined as a circumferential radiolucent line, component migration, or revision for loosening. This study was unable to confirm the findings of others that demonstrated higher failure rates with cemented metal-backed components when compared with all-polyethylene components. The survival of cemented acetabular components with 28-mm head femoral prostheses was worse than the survival of cemented acetabular components with 22-mm femoral heads in other published reports, despite advances in cement techniques. Because of the high rate of loosening of cemented 28-mm-inner-diameter acetabular components at 5 and 10 years, the authors no longer use these cemented components for acetabular reconstruction.     

Automated seeded lesion segmentation on digital mammograms

The clinical results of eighty-four total hip arthroplasties performed through a transtrochanteric approach in sixty-seven patients who had a high dislocation of the hip (the femoral head completely out of the acetabulum), from 1976 to 1994, were reviewed. The acetabular component was placed in the true acetabulum and the femur was shortened at the level of the femoral neck, along with release of the psoas tendon and the small external rotators, in order to facilitate reduction of the components and to avoid neurovascular complications. Eleven hip prostheses (13 per cent) failed at a mean of 6.4 years (range, two months to sixteen years) postoperatively; the failure was due to aseptic loosening of both components in four hips, aseptic loosening of the stem only in three, late infection in three, and malpositioning of the acetabular component that caused recurrent dislocations in one. The other seventy-three hips were functioning well at the latest follow-up examination, two to twenty years (mean, 7.1 years) postoperatively. The overall cumulative rate of success was 92.4 per cent (95 per cent confidence interval, 89.5 to 95.3 per cent) at five years and 88.0 per cent (95 per cent confidence interval, 82.2 to 93.8 per cent) at ten years. We believe that this operative technique of total hip arthroplasty is effective for the treatment of the difficult condition of high dislocation of the hip.     

Results of total hip arthroplasty for Crowe Type III developmental hip dysplasia

From 1969 through 1980, 90 hips in 82 patients had cemented total hip arthroplasty for Type III developmental hip dysplasia. Seventy hips were reviewed at an average of 16.6 years (range, 5-23 years) after operation. Aseptic loosening developed in 53% of acetabular cups and 40% of femoral stems. Despite attempts to place acetabular components in the anatomic center, 18 cups (25.7%) were placed outside that area. Using a measurement method to determine the true acetabular region and approximate femoral head center, final acetabular loosening strongly correlated with initial cup placement. Loosening occurred in 15 of 18 cups (83.3%) initially positioned outside of the true acetabular region compared with loosening in 22 of 52 cups (42.3%) initially positioned within the true acetabular region. Acetabular loosening also correlated with initial lateral displacement or initial superior displacement of the hip center from the approximate femoral head center. Initial cup placement medial to the approximate femoral head center was predictive of successful long term acetabular component fixation. The method of acetabular reconstruction did not affect eventual cup loosening. Placement of the hip arthroplasty center of rotation in or near the true acetabular region is recommended.     

Total hip replacements using the ceramic Mittelmeier prosthesis

One hundred twelve consecutive primary total hip replacements were performed for osteoarthritis or osteonecrosis by a single surgeon using the Mittelmeier ceramic prosthesis without cement between January 1983 and July 1984. Ninety-three of these hips were followed prospectively to a minimum of 60 months and a median of 108 months. Five (5.4%) hips have been revised for loosening. Of the remaining hips, 77 (87.5%) were rated clinically satisfactory. Cumulative survival probability using revision as endpoint was estimated to be 92.7% at 5 years and 87.9% at 10 years. However, overall mechanical failure rates were 21.5% for the cup and 22.6% for the stem. There was no case of either femoral or acetabular osteolysis observed.     

Non-cemented acetabular cup in hip arthroplasty. Prosthesis survival and clinical results after 1-8 years

This is a retrospective clinical evaluation of 1028 primary hip arthroplasties performed with the non-cemented Harris-Galante I acetabulaer cup. Hospital records regarding all hips operated from July 1985 through March 1992 were evaluated after a median of 48 (12-93) months. Furthermore, questionnaires were sent out to all patients still alive in order to establish the actual function of the hips. At time of evaluation, 43 of the 1028 primary acetabular cups (4.2%) had been or were due to be revised. (20 because of one or more episodes of dislocation or displacement of the cup, 10 due to deep infection, eight following aseptic loosening of the cup, two because of implant failure and three due to other reasons). Four hundred and twenty-six hips were without pain, 274 had only mild or slight pain, whereas 84 experienced moderate or worse pain. We conclude, that the results after non-cemented hemispheric acetabular arthroplasties in this study are satisfying with a low rate of aseptic loosening.