Reconstruction of the rotation center of the hip after oblong cups in revision total hip arthroplasty

Background

The preoperative bone defect and the reconstruction of the center of rotation of the hip are critical in acetabular revision surgery. Uncemented oblong cups are employed in order to manage these issues. We analyzed the clinical results and rates of revision of two different uncemented oblong cups, the reconstruction of the center of rotation of the hip, as well as the rate of radiological loosening and possible risk factors.

Materials and methods

Forty-five patients (46 hips) underwent acetabular revision surgery using two different uncemented oblong cups. We assessed the clinical results and the survival rate for revision and aseptic loosening. Intraoperative bone loss was classified according to Paprosky, and acetabular reconstruction was assessed according to Ranawat. The mean follow-up was 7.2 years (range 4–11 years).

Results

There were four re-revisions (three due to aseptic loosening); the survival rate for re-revision due to aseptic loosening was 60.1 % at seven years. The mean distance between the center of the femoral head prosthesis and the approximate center of the femoral head improved from 21.5 to 10.2 mm. Thirteen cups showed radiological loosening; the survival rate for radiological loosening at seven years was 40.54 %. A smaller postoperative horizontal distance was correlated with cup loosening.

Conclusions

Although optimal acetabular reconstruction can be achieved by using oblong uncemented cups in revision hip surgery, the clinical and radiological results are not encouraging. Excessive medialization of the cup may increase the rate of loosening.     

The Bicontact cementless primary total hip arthroplasty: long-term results

We report on a prospective series of 201 primary uncemented total hip arthroplasties with a Bicontact prosthesis at a mean follow-up of 12.9 years. The mean Harris hip score improved from 41 before surgery to 89 at final follow-up. Two femoral stems, one each for infection and fracture, and 12 cups were revised. The mean number of years to revision post-primary surgery was 8.7 years (six months to 16 years). The cumulative survival of the prosthesis was 95.42% for any cause at ten years and 93.57% at 12 years. Survivorship for aseptic loosening of the femoral stem was 100%. In our series, the Bicontact uncemented total hip arthroplasty stem without hydroxyapatite coating showed excellent survival and the cup survival was comparable to other leading series.     

Survival analysis of cementless grit-blasted titanium total hip arthroplasties

Although about 200000 cementless Zweymüller-Alloclassic total hip arthroplasties (THAs) were carried out worldwide in the last decade, the survival analysis of these prostheses was not available in the 2000 report of the Swedish national hip arthroplasty registry. We report a prospective survivorship analysis of 200 consecutive grit-blasted cementless Alloclassic primary THAs carried out since 1988. Using surgical, clinical and radiological endpoints for the stem and the threaded cup the ten-year survivorship was 91.5% for reoperation for any cause, 96.4% for hip pain (Merle d'Aubigné score < 5 points, clinical failure), 99.4% for definite aseptic loosening (radiological failure) and 99.3% for revision for aseptic loosening. Using the Swedish registry criteria of primary osteoarthritis and revision for aseptic loosening as the endpoint, the survival rate of 99.1% at ten years for the subgroup of 157 Alloclassic THAs in osteoarthritis compares favourably with that of the best modern cemented hip replacements reported in the Swedish arthroplasty registry.     

Acetabular revision in total hip replacement with a press-fit cup

The need for supplementary screw fixation in acetabular revisions is still widely debated. We carried out 439 acetabular revisions over an eight-year period. In 171 hips with contained or small segmental defects, the Morscher press-fit cup was used. These revisions were followed prospectively. No screws were used for additional fixation. A total of 123 hips with a mean follow-up of 7.4 years (5 to 10.5) were available for clinical and radiological review. There was no further revision of a press-fit cup for aseptic loosening. Radiological assessment revealed osteolysis in three hips. Of the original 171 hips there was cranial and medial migration of up to 6 mm at two years in 44 (26%). No further migration was seen after the second post-operative year. Acetabular revision without screws is possible with excellent medium-term results in well selected patients.     

Excellent Long-Term Survival Rate of Polished,Tapered, Cemented Stems in Patients Aged 35 Years or Younger With Avascular Necrosis or Inflammatory Arthritis of the Hip

BackgroundTotal hip arthroplasty (THA) for avascular necrosis (AVN) or inflammatory arthritis (IA) comes with a relatively high risk of aseptic stem loosening, especially in young patients. There are limited long-term data on the survivorship of polished, tapered, cemented stems in this population. We therefore performed a single-center retrospective study investigating the survival of this particular stem type in young patients with AVN or IA.MethodsAll patients aged ≤35 years who had received a THA for AVN or IA operated on by the senior author between 1990 and 2010 at the University Hospitals Leuven were identified. In total, 85 THAs in 62 patients were included. Primary endpoint was revision of the femoral component for aseptic loosening. Secondary endpoints were revision of the acetabular component for aseptic loosening, revision for other reasons, and the presence of radiolucencies around the components.ResultsThe mean follow-up for the entire cohort was 18.0 ± 5.3 years (range 8.0-28.9). Taking revision for aseptic loosening as endpoint, the survival of cemented stems was 100% after 15 years and 95.1% after 20 years. Survival of uncemented cups (91.3%) was significantly better than survival of cemented cups (50.3%) after 20 years of follow-up for aseptic loosening. Taking revision for any reason as endpoint, the survival of THAs with uncemented and cemented cups was 90% and 43.1% at 20 years respectively. Radiolucencies developed in the cement mantles around 11 of the 81 nonrevised stems, mainly in zones 1 and 7.ConclusionIn this cohort of young patients with high-risk profiles for aseptic stem loosening, polished, tapered, cemented stems showed excellent long-term survival rates and they therefore remain a viable alternative to uncemented stem designs.     

Long-term results of the threaded Weill cup in primary total hip arthroplasty

Uncemented, threaded acetabular components with smooth surface treatment were widely used in continental Europe in the 1970s and 1980s for primary total hip arthroplasty (THA). Previously published studies showed high failure rates in the mid-term. In a consecutive series of 116 patients, 127 threaded cups with smooth surface treatment (Weill cup; Zimmer, Winterthur, Switzerland) were implanted in combination with one type of uncemented stem. Patients were followed up clinically and radiographically. Mean time of follow-up was 17 years (range 15–20). At the time of follow-up, the acetabular component had been revised or was awaiting revision in 30 hips (24%). Two hips were revised for infection and 23 for aseptic loosening. Four polyethylene liners were exchanged because of excessive wear. One hip was awaiting revision. The survival rate for all acetabular revisions including one hip awaiting revision was 75% (95%CI: 65–85%) at 17 years. These results support the view that smooth, threaded acetabular components do not provide satisfactory long-term fixation and should be abandoned. It is important to closely monitor patients with these components as the failure rate remains high in the long-term.     

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.     

Long-term results of the standard Wagner cup

Cementless acetabular components gained popularity because of the increased rate of loosening associated with cemented cups after intermediate and long-term follow-up. There are few long-term follow-up studies of cementless acetabular components. This study aims to evaluate the clinical and radiological long-term results of the press-fit standard Wagner Cup. Between January 1, 1994 and June 30, 1994, 118 implantations of a standard Wagner Cup were performed, and 102 implants were clinically and radiographically followed-up after a mean of 12.0 years. The Merle d’Aubigné score improved from a preoperative mean of 9.5 to 17.2 at latest follow-up. Early postoperative complications included two deep haematomata requiring needle aspiration, two deep vein thromboses, one pulmonary embolism, two temporary lesions of the sciatic nerve, one single event of THR dislocation and one recurrent dislocation. Two isolated cup revisions and five more complete total hip replacements were performed for aseptic loosening. The overall survival rate at 12 years was 93.1% (95/102). The standard Wagner cup yields very good long-term results.     

The uncemented Bi-Contact total hip arthroplasty

We reviewed a consecutive series of 153 uncemented Bi-Contact (Aesculap, Tuttlingen, Germany) total hip arthroplasties (THAs) in 138 patients who had been followed for at least 5 years (mean, 6.8 years; range, 5-9 years). The Bi-Contact uncemented THA consists of a straight femoral stem made of titanium alloy. The proximal portion of the stem is titanium plasma-sprayed. The cup is press-fit with or without hydroxyapatite coating with a facility for anchoring screws with a snap-fit polyethylene liner. The mean age of the patients was 70.8 years (range, 41-94 years). The mean preoperative Harris hip score of 41 (range, 20-80) improved postoperatively to a mean of 92 (range, 56-96). Three acetabular cups were revised for aseptic loosening, and 1 cup was revised for recurrent dislocation. To date, none of the stems have been revised for aseptic loosening. Radiographic evaluation of the remaining 149 hips revealed that the acetabular cup was stable in 146 hips and possibly unstable in the remaining 3 cases with nonprogressive osteolysis behind the cup. None of the stems showed any evidence of instability. Using the recommendation of revision as the endpoint, the cumulative survival for the prosthesis was 97.3% at a mean follow-up of 6.8 years (95% confidence interval, 95.9-99.4), with stem survival of 100%. In the medium-term, these results are comparable to cemented primary THA and justify the continued use of this prosthesis.     

Extra-large uncemented hemispherical acetabular components for revision total hip arthroplasty

BACKGROUND: Extra-large uncemented components provide several advantages for acetabular revision, but limited information is available on the results of their use. The purpose of this study was to evaluate, at a minimum of five years, the results associated with the use of an extra-large uncemented porous-coated component for acetabular revision in the presence of bone loss. METHODS: Eighty-nine extra-large uncemented hemispherical acetabular components were used for revision after aseptic failure of a total hip arthroplasty in forty-six men and forty-three women (mean age at revision, fifty-nine years; range, thirty to eighty-three years). The revision implant (a Harris-Galante-I or II cup fixed with screws) had an outside diameter of > or = 66 mm in men and > or = 62 mm in women. Seventy-nine patients had a segmental or combined segmental and cavitary acetabular bone deficiency before the revision. Particulate bone graft was used in fifty-four hips and bulk bone graft, in nine. RESULTS: One patient died with the acetabular component intact and two patients were lost to follow-up within five years after the operation. At the time of the last follow--up, four acetabular components had been removed or revised again (two for aseptic loosening). All of the remaining patients were followed clinically for at least five years (mean, 7.2 years; range, 5.0 to 11.3 years). In the hips that were not revised again, only two sockets had definite radiographic evidence of loosening. All four of the sockets that loosened were in hips that had had combined cavitary and segmental bone loss preoperatively. In the hips that were not revised again, the mean modified Harris hip score increased from 56 points preoperatively to 83 points at the time of the most recent follow-up. The most frequent complication, dislocation of the hip, occurred in eleven patients. The probability of survival of the acetabular component at eight years was 93% (95% confidence interval, 85% to 100%) with removal for any reason as the end point, 98% (95% confidence interval, 92% to 100%) with revision for aseptic loosening as the end point, and 95% (95% confidence interval, 88% to 100%) with radiographic evidence of loosening or revision for aseptic loosening as the end point. CONCLUSIONS: This study demonstrates that extra-large uncemented components used for acetabular revision in the presence of bone loss perform very well and have a low rate of aseptic loosening at the time of intermediate-term follow-up.     

Cementless total hip arthroplasty using a threaded cup and a rectangular tapered stem. Follow-up for ten to 17 years

We carried out a clinical and radiological review of 103 cementless primary hip arthroplasties with a tapered rectangular grit-blasted titanium press-fit femoral component and a threaded conical titanium acetabular component at a mean follow-up of 14.4 years (10.2 to 17.1). The mean Harris hip score at the last follow-up was 89.2 (32 to 100). No early loosening and no fracture of the implant were found. One patient needed revision surgery because of a late deep infection. In 11 hips (10.7%), the reason for revision was progressive wear of the polyethylene liner. Exchange of the acetabular component because of aseptic loosening without detectable liner wear was carried out in three hips (2.9%). After 15 years the survivorship with aseptic loosening as the definition for failure was 95.6% for the acetabular component and 100% for the femoral component.     

A cementless hip system with a new surface for osseous integration

Purpose

The failure of total hip systems caused by wear-particle-induced loosening has focused interest on factors potentially affecting wear rate. Remnants of the blasting material were reported on grit-blasted surfaces for cementless fixation. These particles are believed to cause third-body wear and implant loosening. The purpose of this study was to evaluate the early clinical and radiological outcomes of a cementless hip system with a new, contamination-free, roughened surface with regard to prosthesis-related failures.

Methods

Between May 2004 and March 2009, 202 consecutive primary total hip arthroplasties (THAs) (192 patients with a mean age of 62.6 years) were performed using a cementless stem (Hipstar®) and a hemispherical acetabular cup (Trident®).

Results

At a minimum follow-up of two years, five revisions (2.5 %) due to aseptic loosening of the stem and three (1.5 %) of the cup were necessary. The cumulative rate of prostheses survival, counting revision of both components and with aseptic failure as end point, was 92.9 % at 8.8 years. Radiolucent lines up to three millimetres were evaluated in the proximal part of the femur in 61 % of cases.

Conclusions

Although the incidence of radiolucent lines was decreased, the revision rate was considerably increased compared to other uncemented hip implants with grit-blasted surfaces in the short- to mid-term follow-up of our study. Subsequent studies are needed to confirm whether these changes in implant material and surface affect the radiological and clinical outcome in the long term.     

Clinical and radiological outcome following total hip arthroplasty with an uncemented trabecular metal monoblock acetabular cup

Uncemented acetabular components are associated with a significant incidence of polyethylene wear and secondary osteolysis. The new tantalum/polyethylene composite (Hedrocel) acetabular component is designed to reduce the polyethylene wear and to increase the longevity of the acetabular cups. We report our short- term clinical outcome and patient satisfaction following use of an uncemented tantalum acetabular component in a single centre. During 1999 to 2002, 113 uncemented tantalum acetabular cups were implanted in 105 patients in our institution. The average age at operation was 56.8 years. All patients were assessed pre- and post-operatively with the Oxford 12 item hip questionnaire and standard radiographs of the pelvis. At a mean follow-up of 32 months (range: 18 to 48), 112 Hedrocel cups were assessed in 104 patients. Subjective patient's satisfaction was also assessed. At the time of evaluation, one patient had died due to an unrelated cause. Eight patients had bilateral acetabular cups implanted. The mean Oxford hip score improved from 45 preoperatively to 14 post-operatively. Subjectively 99% were very satisfied or satisfied. Only one patient expressed dissatisfaction about the outcome of this surgery. Radiologically, there were no signs of cup loosening or wear. This study shows that at short-term the new uncemented tantalum/polyethylene composite (Hedrocel) acetabular component can yield a satisfactory clinical and radiological outcome and has a high patient satisfaction. Although the short-term result from our centre is very encouraging, similar results from other centres and longer follow-up are required.     

Comparison of the results of cemented,porous-ingrowth,and threaded acetabular cup fixation: A meta-analysis of the orthopaedic literature

A meta-analysis of the orthopaedic literature was performed to evaluate the clinical performance of cementless, threaded acetabular cups. The hypothesis for the study was that the clinical performance of the cementless, threaded acetabular cup is equivalent to that of the cemented and porous-ingrowth acetabular cups. Ninety-five articles were included in the study. There were 1,269 cases in the threaded cup group, 1,979 in the porous control group, and 10,230 in the cemented control group. The primary outcome variable tested was the rate of aseptic loosening of the acetabular components as measured by the revision rates following the index total hip arthroplasty procedure. Other measures of acetabular component loosening that were analyzed included clinical rating scores, pain scores, frequency of radiolucencies according to location and size, frequency of radiolucencies as a separately defined outcome variable, progressive radiolucencies, and component migration. The threaded cup group was found to have a significantly higher rate of revision, clinical and pain score failures, progressive radiolucencies and migrations when compared with the cemented and porous control groups (P < .05). Despite the many limitations of meta-analyses and the poor state of the orthopaedic literature database, this study provides a reasonable comparison of the clinical performance of threaded acetabular cups with that of cemented and porous-ingrowth acetabular cups.     

Revision of failed acetabular components utilizing a cementless oblong cup: an average 9-year follow-up study

Introduction  Failure of acetabular components often leads to bone loss with extensive elongated defects in the surrounding bone. In these cases, reconstruction is challenging and stable fixation of the revision implant difficult. The use of an oblong cup has been described as an option for acetabular reconstruction in such revisions. We report the first long-term results obtained with this implant to date. Materials and methods  Fifty-six longitudinal oblong revision cups (LOR™) were evaluated clinically and radiologically after a follow-up of 8–12 years (average 9 years). The defects treated with the LOR™ cup ranged from Paprosky type 1–3. Allogenic cancellous bone chips were additionally used in 31 reconstructions to fill cavitary defects. Results  Based on radiological criteria, 50 acetabular implants underwent osseointegration without any definitive signs of loosening; 2 consistently exhibited zonal radiolucent lines that were always smaller than 2 mm, 1 migrated by around 3 mm. None of these cases exhibited any clinical symptoms. In 11 cases where acetabular defects manifested postoperatively, 8 were remodeled completely and 3 partially at final follow-up. Three revision implants migrated farther than 5 mm and had to be revised before 32-month follow-up. In addition, 1 septic implant failure occurred. After an average follow-up of 9 years, 93% of the investigated implants remained in situ without further revision and 95% without aseptic implant failure. Conclusion  This 12-year clinical study demonstrates that the LOR™ cup offers a successful concept for the revision of failed acetabular components that also promotes the biological reconstruction of bony defects. Compared with other methods with similarly long follow-ups, our long-term results prove this procedure has a very low rate of revision and aseptic implant failure.     

Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old

BACKGROUND: Acetabular bone deficiency can present a challenge during total hip arthroplasty, especially in young patients. The purpose of the present study was to evaluate the long-term clinical and radiographic outcomes of primary and revision acetabular reconstruction with use of an impaction bone-grafting technique and a cemented polyethylene cup in young patients who had preexisting acetabular bone deficiency. METHODS: Forty-two consecutive acetabular reconstructions were performed in thirty-seven patients who were younger than fifty years old (average, 37.2 years old). The impaction bone-grafting technique was used for twenty-three primary and nineteen revision acetabular reconstructions. Twenty-eight patients (thirty-one hips) were available for review after a minimum duration of follow-up of fifteen years. Clinical and radiographic results were assessed, and survivorship analysis was performed with the Kaplan-Meier method. RESULTS: Eight hips were revised at a mean of twelve years (range, three to twenty-one years) after a primary reconstruction (four hips) or revision reconstruction (four hips). The revision was performed because of aseptic loosening of the acetabular component in four hips and because of culture-proven septic loosening in two. Two additional cups (both in hips that had had a revision reconstruction) were revised, during revision of the femoral stem, because of wear (one hip) or because of persistent intraoperative instability (one hip). Twenty-eight hips (in twenty-five patients) had retention of the acetabular component for a minimum of fifteen years. The mean Harris hip score for that group was 89 points. Twenty-six of these twenty-eight hips had no or slight pain. Kaplan-Meier analysis revealed a twenty-year survival rate of 80% (95% confidence interval, 67% to 94%) with acetabular revision for any reason as the end point and of 91% (95% confidence interval, 80% to 100%) with acetabular revision because of aseptic loosening as the end point. CONCLUSIONS: Acetabular reconstruction with use of impaction bone-grafting and a cemented polyethylene cup is a reliable and durable technique that is associated with good long-term results in young patients with acetabular bone-stock defects.     

Evaluation of a porous tantalum uncemented acetabular cup in revision total hip arthroplasty: clinical and radiological results of 60 hips

Long-term survival of the acetabular component in revision total hip arthroplasty (THA) is determined by initial implant stability and bone ingrowth. Highly porous Trabecular Metal (TM, Zimmer, Inc, Warsaw, Ind) facilitates ingrowth and may be an ideal material for revision THA. The outcome and survivorship of a TM, nonmodular, uncemented acetabular cup were assessed in 60 consecutive patients undergoing revision THA (mean follow-up, 42 months; range, 14-68 months). Most (55/60) acetabular cups were implanted without screw fixation. Mean Harris Hips Scores improved from 74.8 preoperatively to 94.4 at last follow-up. Serial radiographs demonstrated excellent bone apposition and bone graft incorporation. Complications were limited to 7 cases of dislocation and 1 revision for aseptic loosening. The TM acetabular cup appears suitable for use in revision THA and warrants further study.     

Eleven- to 14-year follow-up results of cementless total hip arthroplasty using a third-generation alumina ceramic-on-ceramic bearing

To analyze long-term survivorship of cementless total hip arthroplasties (THAs) with the third-generation alumina ceramic-on-ceramic bearing, 100 consecutive THAs between 1996 and 1998 were reviewed. One cup and 2 stems were revised due to aseptic loosening. Another cup showed chipping of the acetabular liner at 8 years and required cup revision. The remaining hips showed stable bone ingrowth fixation with no osteolysis at the final follow-up. The 14-year survivorship as the end point of revision was 97.9% for the cup, 97.8% for the stem, and 95.7% for the overall implants, respectively. We conclude that cementless THA with the third-generation ceramic-on-ceramic hip bearing provided an excellent survivorship and eliminated periprosthetic osteolysis for 11 to 14 years.