Cementless Acetabular Components Research Articles

Polyethylene Wear and Osteolysis Is Associated With High Revision Rate of a Small Sized Porous Coated THA in Patients With Hip Dysplasia

The outcome of 25 primary THAs in patients with hip dysplasia using the AML Bantam femoral stem (DePuy) is reported. Age at operation averaged 43±10years. Twenty-two of 25 stems were cementless. All cementless acetabular components had conventional or cross-linked polyethylene and screws. Follow-up averaged 11±5years (range 4–18). Four cementless stems were revised after 3, 4, 8, and 9years; 2/3 cemented stems were revised at 8 and 18years. Femoral revisions demonstrated extensive conventional polyethylene wear, periprosthetic osteolysis and loosening. Five entire cups were revised for wear and loosening; four liners were replaced. Harris Hip Scores for patients with retained stems went from 43±12 to 85±13. High revision rates with the proximally porous coated Bantam stem are due to loss of fixation, often associated with polyethylene wear and osteolysis.

Combined cementless acetabular reconstruction with bone grafting in total hip replacement after acetabular fractures treated nonoperatively

BackgroundAcetabular fractures are serious and challenging orthopedic injuries. Many of these fractures may potentially result in late complications that can occur with or without initial surgical treatment. Such complications usually end in post-traumatic arthritis. Once symptomatic post-traumatic arthritis has developed, options for salvage are generally limited to total hip arthroplasty (THA) and arthrodesis. Whether initial nonoperative or operative treatment was used to manage acute and highly displaced acetabular fractures, formidable problems such as nonunion, malunion, bone defect, and heterotopic bone may complicate the arthroplasty. More recent studies have evaluated the techniques of THA after an acetabular fracture initially managed by a nonoperative or an operative course. Various reconstructive strategies have been assessed in an attempt to advice improvements in the surgical protocol.AimThe aim of the work was to evaluate the early results of THA using cementless acetabular components combined with bone grafting in the reconstruction of the hip joint in patients with post-traumatic arthritis after an old nonoperatively treated acetabular fracture or fracture dislocation.Patients and methodsThis prospective study included 12 patients who had end-stage arthritis. All patients had old acetabular fractures either with or without hip dislocation. All patients had a nonoperative treatment for their fractures 1-5 years before presentation for total hip replacement. Clinical, laboratory, and radiological evaluations before surgery were performed. In all patients, conventional cementless cups combined with bone graft from their own femoral heads were used to fill defects and reconstruct the acetabulum. The duration of the follow-up period ranged from 1 to 3 years.ResultsClinically, there was marked improvement in the Harris Hip Score (satisfactory results in 83.33% of the study group at the last follow-up) with special concern to postoperative pain relief, the range of hip movement, and the walking distance. Radiologically, all cups were placed in the normal hip center with no early signs of cup loosening, migration, or position change with good integration of the bone graft.ConclusionThe results were very satisfactory and significantly in favor of using this technique using conventional cementless cups combined with autogenous bone grafting to reconstruct the acetabulum in certain cases of old united fractures of the acetabulum saving the extra costs of metallic augments, special cups, or modular reconstructions using cages or rings and achieving a superior biological and biomechanical reconstruction.

Four- to Six-year Follow-up of Primary THA Using Contemporary Titanium Tapered Stems

Tapered cementless femoral components have been used in total hip arthroplasty constructs for more than 20 years. In the past 5 to 10 years, these stems have gained popularity in the United States. The purpose of this study was to evaluate the results of the authors’ initial experience using a contemporary tapered, proximally porous-coated, titanium femoral component at 4 to 6 years of follow-up. Eighty-eight patients underwent 100 total hip arthroplasties using the Summit stem (DePuy, Warsaw, Indiana) and a cementless acetabular component. Average age at the time of surgery was 61.6 years. Patients were prospectively followed for 4 to 6 years or until death. Patients were evaluated clinically using Harris Hip Scores and the need for revision. Radiographs were evaluated for femoral loosening and osteolysis. At final follow-up, no hips had been revised for femoral or acetabular loosening. Two hips required revision for dislocation and 1 for early femoral fracture. Bony ingrowth was seen in all but 2 femoral components. There was 1 instance of proximal femoral osteolysis and none distally on radiographs (cross-linked polyethylene was used in 73% of cases). There were 2 cases of severe stress shielding. One percent of cases had an early fracture (too tight) and 1% subsided without ingrowth (too loose). One patient reported significant thigh pain that did not limit activity. At final follow-up, the Summit femoral component demonstrated durable results at 4 to 6 years. Stability of the implant without femoral fracture is paramount.

Revisiones acetabulares con injertos óseos impactados: técnica quirúrgica y serie de casos

IntroductionImpaction bone grafting technique is useful when the orthopaedic surgeon is faced with large cavitational acetabular defects with compressed particulate bone grafts, followed by insertion of either a cemented or cementless acetabular component. The technically demanding nature of the procedure, mandate the extensive training of the orthopedic surgeon who practiced the procedure. MethodA case series study was performed from September 2006 to September 2011, including 27 patients with either acetabular or acetabular and femoral revision surgery with slight variations of the technique according to each particular case. ResultMean age of patients was 68.3 years (44 to 81). Among all included patients (27 patients), 21 were female and the remaining 6 were male. All prosthetic revision components were cemented. There was only one post-surgery hip dislocation. All cement bone interface radiolucent lines found were less than 1mm in length. A 2mm protrusio was found out in only one acetabular component along the first 2 follow up years, but it stopped by itself without the necessity of any further intervention. DiscussionWhen philosophy underneath this surgical procedure is well understood by the surgeon, enough bone graft availability is being assure, a correct selection of candidate patient is performed, and when the procedure is performed by a well-trained orthopedic surgeon, results seems to be adequate to fairly recommend this technique.

Dimensional analysis of total hip arthroplasty polyethylenes

ObjectiveThis paper performs a dimensional analysis of different total hip arthroplasty polyethylenes, cemented and non-cemented, Brazilian made and imported. MethodsIt was considered acetabular components with 50mm for the 28mm femoral heads. Dimensional analysis was performed on a 3D coordinate Carl-Zeiss robotic device. Polyethylene thickness and its external measurements (maximum diameter and diameter for the femoral head) were measured. ResultsThe minimum thickness of the polyethylene was guaranteed on all tested components. The thickness of cemented acetabular varied from 19.185mm to 25.358mm, while the thickness of the non-cemented acetabular varied from 12.451mm to 19.232mm. The thickness was 27.96% lower in non-cemented acetabular components. With respect to the polyethylene acetabular cavity that receives the femoral head, all internal diameters exhibit at least 28mm. In relation to the maximum outer diameter of the polyethylene, only one cemented acetabular component reached 50mm in diameter. ConclusionsThere are large differences in measurements between brands and models analyzed. Cementless acetabular components have the smaller thickness. The diameters of non-cemented acetabular were also lower than those cemented at the expense of their need to insert into the metal-back.

Acetabular protrusio

There are few reports describing the technique of managing acetabular protrusio in primary total hip replacement. Most are small series with different methods of addressing the challenges of significant medial and proximal migration of the joint centre, deficient medial bone and reduced peripheral bony support to the acetabular component. We describe our technique and the clinical and radiological outcome of using impacted morsellised autograft with a porous-coated cementless cup in 30 primary THRs with mild (n = 8), moderate (n = 10) and severe (n = 12) grades of acetabular protrusio. The mean Harris hip score had improved from 52 pre-operatively to 85 at a mean follow-up of 4.2 years (2 to 10). At final follow-up, 27 hips (90%) had a good or excellent result, two (7%) had a fair result and one (3%) had a poor result. All bone grafts had united by the sixth post-operative month and none of the hips showed any radiological evidence of recurrence of protrusio, osteolysis or loosening. By using impacted morsellised autograft and cementless acetabular components it was possible to achieve restoration of hip mechanics, provide a biological solution to bone deficiency and ensure long-term fixation without recurrence in arthritic hips with protrusio undergoing THR.

Comportamiento radiológico de los cotilos no cementados y su correlación clínica

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><strong>In­tro­duc­ción: </strong><span>Luego de colocar un cotilo no cementado es frecuente encontrar imágenes radiolúcidas entre la copa y el lecho óseo circundante en la radiografía posoperatoria inmediata. El propósito de este estudio retrospectivo fue evaluar el comportamiento clínico y radiológico de estas imágenes, si se producían cambios en la posición de los componentes y si afectaban su duración.</span></p><p><span><br /> </span><strong>Materiales­ y­ métodos: </strong><span>Se analizaron 121 cotilos no cementados Duraloc® (Depuy J&J), 53 del modelo 100 y 68 del modelo 300. La serie estaba formada por 48 mujeres y 73 varones, con un promedio de edad de 58 años y un seguimiento de 5,2 años. Se realizó una medición manual de las radiografías en la que se determinó la presencia de la brecha radiolúcida entre el componente y el fondo acetabular, la posición y la orientación de las copas. Cuando se observó dicha brecha, las mediciones se repitieron en las radiografías de seguimiento.</span></p><p><span><br /> </span><strong>Resultados: </strong><span>Veintiocho (23,14%) pacientes, 9 casos del modelo 100 y 19 del modelo 300 tenían brechas. El tamaño fue de 3,5 mm en promedio, y más frecuente en la zona II y, en el 86% de los casos, se rellenó, en promedio, a los 22 meses de la cirugía. En dos casos, el relleno fue parcial y, en 4, no se modificó. El puntaje de cadera de Harris en el grupo con una brecha fue de 94,3 y el de aquellos sin la brecha, de 93,9. No se registraron aflojamientos en ningún paciente.<br /> </span></p><p><strong>Conclusiones: </strong><span>La presencia de líneas radiolúcidas en la radiografía posoperatoria inmediata, tras la colocación de un cotilo no cementado, tiene una duración finita en la mayoría de los casos y, en consonancia con otros reportes, no representa una amenaza para la duración a mediano y largo plazo del componente. </span></p></div></div></div><p> </p><div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p> </p></div></div></div>

Análise dimensional de diferentes acetábulos usados na artroplastia total do quadril

ObjectiveThis paper performs a dimensional analysis of different total hip arthroplasty polyethylenes, cemented and non-cemented, brazilian made and imported. MethodsIt was considered acetabular components with 50mm for the 28mm femoral heads. Dimensional analysis were performed on a 3d coordinate Carl-Zeiss robotic device. Polyethylene thickness and its external measurements (maximum diameter and diameter for the femoral head) were measured. ResultsThe minimum thickness of the polyethylene was guaranteed on all tested components. The thickness of cemented acetabular varied from 19.185mm to 25.358mm, while the thickness of the non-cemented acetabular varied from 12.451mm to 19.232mm. The thickness was 27.96% lower in non-cemented acetabular components. With respect to the polyethylene acetabular cavity that receives the femoral head, all internal diameters exhibit at least 28mm. In relation to the maximum outer diameter of the polyethylene, only one cemented acetabular component reached 50mm in diameter. ConclusionsThere are large differences in measurements between brands and models analyzed. Cementless acetabular components have the smaller thickness. The diameters of non-cemented acetabular were also lower than those cemented at the expense of their need to insert into the metal-back.

A Randomized Trial Comparing Acetabular Component Fixation of Two Porous Ingrowth Surfaces Using RSA

Several new porous ingrowth surfaces for acetabular component fixation have recently been developed. The purpose of this study was to compare the in vivo fixation achieved by two different porosity ingrowth surfaces using radiostereometric analysis (RSA). Sixty-two patients undergoing primary total hip arthroplasty (THA) were randomized to receive a cementless acetabular component with either a 61% high porosity asymmetric titanium porous surface (StikTite, Smith and Nephew, TN, USA) or a 45% low porosity sintered bead porous surface (Roughcoat, Smith and Nephew, TN, USA). RSA and clinical follow-up examinations were done post-operatively, 6-weeks, 3-months, 6-months, 1-year and 2-years. Both the high porosity StikTite and lower porosity Roughcoat surfaces provided excellent biologic fixation.

Outcomes of Open Reduction for Developmental Dysplasia of the Hip: Does Bilateral Dysplasia Have a Poorer Outcome?

The purpose of this study was to compare the outcomes of surgical treatment in children of walking age with unilateral and bilateral developmental dysplasia of the hip (DDH). We examined the records of fifty-six children of walking age with bilateral dysplasia and 156 children of walking age with unilateral dysplasia treated with open reduction and pelvic osteotomy with or without femoral osteotomy from 1990 to 2000. The minimum duration of follow-up was five years. The mean age at surgery was thirty-four months in the bilateral group and twenty-five months in the unilateral group. Preoperative radiographs were evaluated to determine the Tönnis grade of the dislocation and the acetabular index, and the latest radiographs were evaluated to determine the Severin classification. The Kalamchi and MacEwen classification was used to assess osteonecrosis, and the McKay classification was used to assess the clinical outcome at the time of the latest follow-up. For the statistical analyses, we selected the worse side in patients in the bilateral group as the index hip if the outcome was asymmetrical and the left hip if the outcome was symmetrical. The Fisher exact and Student t tests were used for comparisons of outcomes between the groups. Multiple logistic regression models were used to analyze factors associated with osteonecrosis and with the McKay classification. Age at surgery and preoperative Tönnis grade differed significantly between the groups. Forty-five (80.3%) of the patients in the bilateral group and 135 (86.5%) of the patients in the unilateral group had a satisfactory Severin classification (Ia, Ib, or II); the difference between the groups was not significant. According to the McKay classification, twenty-six (46%) of the patients in the bilateral group had an satisfactory outcome compared with 111 (71%) of the patients in the unilateral group (p = 0.006). Osteonecrosis was significantly greater in the bilateral group as well (p = 0.01). Patient age at surgery and Tönnis grade were risk factors for osteonecrosis. Older age and bilaterality were associated with a poorer McKay classification. The logistic regression analysis was repeated after removing the nineteen patients (34%) in the bilateral group who had an asymmetrical outcome, and this analysis confirmed that asymmetrical outcome was a risk factor for a poorer McKay classification. Our data confirmed that the clinical outcome of bilateral developmental dysplasia of the hip was worse primarily because of asymmetrical outcomes. Age and Tönnis grade played an important role in the risk of occurrence of osteonecrosis. The radiographic outcome according to the Severin classification did not differ significantly between the groups.

Polyethylene Wear and Osteolysis After Cementless Total Hip Arthroplasty with Alumina-on-Highly Cross-Linked Polyethylene Bearings in Patients Younger Than Thirty Years of Age

We asked whether cementless total hip arthroplasties that made use of alumina-on-highly cross-linked polyethylene bearings would improve hip score and functional activity and reduce the prevalence of polyethylene wear, osteolysis, and aseptic loosening. Consecutive primary total hip arthroplasties were performed in fifty patients (a total of sixty hips among thirty-four men and sixteen women) who were younger than thirty years of age. The average age at the time of the index arthroplasty was 28.3 years (range, twenty-one to twenty-nine years). The average follow-up was 10.8 years (range, ten to twelve years). Osteolysis and polyethylene wear rates were evaluated with use of radiography and computed tomography. The mean Harris hip score, which was 38 points (range, 6 to 45 points) preoperatively, had improved to 95 points (range, 85 to 100 points) at a mean follow-up time of 10.8 years. The mean penetration (and standard error of the mean) of the polyethylene liner was 0.031 ± 0.004 mm per year. No hip had osteolysis or aseptic loosening. At a minimum of ten years and an average of 10.8 years postoperatively, the current generation of cementless acetabular and femoral components with alumina-on-highly cross-linked polyethylene bearings was functioning well and was not associated with the development of osteolysis in our group of patients younger than thirty years of age. While the long-term prevalence of polyethylene wear and osteolysis remains unknown, the midterm data are promising.

Cementless femoral stems: Is there an optimum?

The use of cementless fixation in total hip arthroplasty has been associated with excellent results in several long-term follow-up studies. A majority of total hip arthroplasty performed in the United States has capitalized on this concept, utilizing both cementless acetabular and femoral components. Since the advent of cementless fixation, there has been a substantial evolution in femoral stem design. The individual stem geometry and the location of the porous coating for bone ingrowth are critical to the surgical technique for bone preparation and guide the ensuing success, complications, and even potentially the postoperative rehabilitation.

Bone remodelling around uncemented metallic and ceramic acetabular components

Stress shielding-induced bone resorption around cementless acetabular components has been indicated as a potential failure mechanism that may threaten long-term fixation. Using a bone remodelling algorithm in combination with three-dimensional finite element models of intact and implanted pelvises and musculoskeletal loading during normal walking, the objectives of the study were to investigate the deviations in load transfer due to implantation and bone adaptation around cementless metallic and ceramic acetabular components. Variations in implant-bone interfacial condition affected strain shielding and bone remodelling; strain shielding was higher for the bonded condition as compared to the debonded condition. For bonded interfacial condition, severe bone resorption, 20%-50% bone density reduction, was observed within the acetabulum. Considering debonded implant-bone interface, bone density increase of 50%-60% was observed around the supero-posterior part of acetabulum, whereas bone density reductions were low (2%-15%) in other locations. The implant-bone interface appeared less likely to fail, post-operatively and after bone remodelling. Moreover, the implant-bone micromotion was found to be low, less than 100 µm. Strain shielding and bone remodelling were almost similar for the metallic and ceramic components. Based on the results of this study, the ceramic acetabular component appeared to be a viable alternative to metal.

Acetabular Components in Total Hip Arthroplasty: Is There Evidence That Cementless Fixation Is Better?

The use of cementless acetabular components in total hip arthroplasty has gained popularity over the past decade. Most total hip arthroplasties being performed in North America currently use cementless acetabular components. The objective of this systematic review and meta-analysis was to compare the survivorship and revision rate of cemented and cementless acetabular components utilized in total hip arthroplasty. A primary literature search in PubMed identified 3488 articles, of which 3407 did not meet the inclusion criteria and were excluded. Only English-language articles on either the survivorship or revision rate of primary total hip arthroplasty at a minimum of ten years of follow-up were included. The present study analyzed forty-five articles reporting the long-term outcome of cementless acetabular components, twenty-nine reporting the outcome of cemented acetabular components, and seven comparing cemented and cementless acetabular components. Meta-analysis (with a random-effects model) was performed on the data from the seven comparative studies, and study-level logistic regression analysis (with a quasibinomial model) was performed on the pooled data on the eighty-one included articles to determine a consensus. The studies were weighted according to the number of total hip arthroplasties performed. The meta-analysis did not reveal any effect of the type of acetabular component fixation on either survivorship or revision rate. The regression analysis revealed the estimated odds ratio for survivorship of a cemented acetabular component to be 1.60 (95% confidence interval, 1.32 to 2.40; p = 0.002) when adjustments for factors including age, sex, and mean duration of follow-up were made. The preference for cementless acetabular components on the basis of improved survivorship is not supported by the published evidence. Although concerns regarding aseptic loosening of cemented acetabular components may have led North American surgeons toward the nearly exclusive use of cementless acetabular components, the available literature suggests that the fixation of cemented acetabular components is more reliable than that of cementless components beyond the first postoperative decade.

Atypical Femoral Fractures: What Do We Know About Them?

Background: The use of cementless acetabular components in total hip arthroplasty has gained popularity over the past decade. Most total hip arthroplasties being performed in North America currently use cementless acetabular components. The objective of this systematic review and meta-analysis was to compare the survivorship and revision rate of cemented and cementless acetabular components utilized in total hip arthroplasty. Methods: A primary literature search in PubMed identified 3488 articles, of which 3407 did not meet the inclusion criteria and were excluded. Only English-language articles on either the survivorship or revision rate of primary total hip arthroplasty at a minimum of ten years of follow-up were included. The present study analyzed forty-five articles reporting the long-term outcome of cementless acetabular components, twenty-nine reporting the outcome of cemented acetabular components, and seven comparing cemented and cementless acetabular components. Meta-analysis (with a random-effects model) was performed on the data from the seven comparative studies, and study-level logistic regression analysis (with a quasibinomial model) was performed on the pooled data on the eighty-one included articles to determine a consensus. The studies were weighted according to the number of total hip arthroplasties performed. Results: The meta-analysis did not reveal any effect of the type of acetabular component fixation on either survivorship or revision rate. The regression analysis revealed the estimated odds ratio for survivorship of a cemented acetabular component to be 1.60 (95% confidence interval, 1.32 to 2.40; p = 0.002) when adjustments for factors including age, sex, and mean duration of follow-up were made. Conclusions: The preference for cementless acetabular components on the basis of improved survivorship is not supported by the published evidence. Although concerns regarding aseptic loosening of cemented acetabular components may have led North American surgeons toward the nearly exclusive use of cementless acetabular components, the available literature suggests that the fixation of cemented acetabular components is more reliable than that of cementless components beyond the first postoperative decade.

Use of a revision cup for treatment of Zurich cementless acetabular cup loosening

Loosening of the acetabular cup is one of the most common complications following total hip replacement and has an incidence rate of 1.8% to 36.8%. The objective of this study was to describe the surgical technique for the application of a cementless acetabular component specifically designed for treatment of cup loosening and preliminary clinical experience. The Kyon revision cup is composed of two components; the first is a perforated titanium outer shell with holes for 2.4 mm titanium screws, which is impacted into the acetabulum after removal of the loose cup and reaming of the acetabulum. It is secured with a variable number of screws. The second component is an inner plain titanium cup with an ultra-high-molecular-weight polyethylene insert, which is impacted into the outer shell to obtain press-fit stability. This revision cup was used in 31 dogs with cup loosening and a minimum follow-up period of six months. There were four intra-operative complications and two postoperative complications. The main intra-operative complication was difficulty inserting the inner cup into the outer shell. Postoperative complications included craniodorsal hip luxation in one dog, which was successfully managed, and cup loosening in another dog, which required explantation of the prosthesis. The main advantage of the revision cup appears to be increased implant stability afforded by screw fixation. Our initial clinical results in 31 dogs were promising; all but one dog had a successful clinical outcome.

Cementless Total Hip Arthroplasty in Patients Fifty Years of Age or Younger: A Minimum Ten-Year Follow-up

The durability of total hip arthroplasty in younger patients has been reported to be less than that in older patients. The purpose of this study was to evaluate the results of cementless total hip arthroplasty performed in a consecutive series of patients fifty years of age or younger who were followed for a minimum of ten years. We prospectively followed 100 consecutive patients (115 hips) who were fifty years of age or younger when they were treated with primary cementless total hip arthroplasty with use of a second-generation, extensively porous-coated femoral stem and a cementless acetabular component. The patients were followed for a minimum of ten years, and the results were compared with our patients in the same age group who had total hip arthroplasty with cement. Evaluation included the need for revision, activity questionnaires, six-minute walks, activity level monitoring with an accelerometer, and radiographic evaluation for evidence of loosening, wear, and osteolysis. Seventy-three patients (eighty-two hips) were available for follow-up at ten years (mean, twelve years). Seventeen patients (twenty-three hips) had died, and ten patients (ten hips) were lost to follow-up. The average age at the time of surgery was 40.1 years. Three femoral stems were revised for periprosthetic fracture. No acetabular shell or femoral stem was revised for loosening, and none were loose on radiographs made at the time of a minimum ten-year follow-up. This compares favorably with the cemented cohort, which had poorer survivorship of the implant with regard to revision for aseptic loosening and radiographic loosening. Reoperation for any reason was similar between the two cohorts at ten years, primarily because of the relatively large numbers of revisions for polyethylene wear in the cementless group. Cementless total hip arthroplasty with use of a second-generation, extensively porous-coated stem demonstrated durable fixation in an active, younger population at a minimum follow-up of ten years and had better survivorship with respect to fixation compared with our previously reported cemented cohort.

Cemented polyethylene and cementless porous-coated acetabular components have similar outcomes at a mean of seven years after total hip replacement

The aim of this prospective randomised study was to compare the clinical and radiological results of a cemented all-polyethylene Ultima acetabular component with those of a cementless porous-coated acetabular component (PFC) following total hip replacement (THR). A total of 287 patients received either a polyethylene acetabular component (groupA) or a cobalt-chromium porous-coated component (group B) with an identical cemented femoral component and 28 mm cobalt-chromium head, thus making it the largest study of its type. Patients were evaluated radiologically and clinically using the Harris hip score (HHS). Group A comprised 183 patients (73 male, 110 female) with a mean age of 71.3 years (55 to 89). Group B comprised 104 patients (48 male, 56 female) with a mean age of 69.8 years (56 to 89). A total of 16 patients (13 in Group A, three in Group B) did not have post-operative data for analysis. The mean follow-up in group A was 7.52 years (0.4 to 15.0) and in Group B 7.87 years (0.5 to 14.0). At final follow-up the mean HHS was similar between groups A and B (74.5 (25 to 100) and 78.0 (37 to 100), respectively; p = 0.068). The total number of revisions for any cause was 28, 17 of which were in group A and 11 in group B. The ten-year survivorship was 86.8% (95% confidence interval (CI) 78.4 to 92.1) and 89.2% (95% CI 78.3 to 94.8) for groups A and B, respectively (log-rank p-value = 0.938). A total of 20 cemented and two cementless acetabular components had evidence of acetabular radiolucencies or acetabular component migration at last follow-up (p = 0.001). These results indicate that patients with a cemented all-polyethylene and cementless porous-coated polyethylene lined acetabular component have similar long-term clinical outcomes.

Revision with Cementless Acetabular Components

The purpose of the present study was to analyze the longer-term results for a previously reported cohort of patients who were managed with cementless acetabular fixation at the time of revision arthroplasty. Sixty-one consecutive revision total hip arthroplasties were performed in fifty-five patients with use of a cementless acetabular component and screw-augmented fixation. This series was evaluated at minimum of twenty years. Twelve patients (fourteen hips) were living at twenty years. In this group of sixty-one arthroplasties, there were nineteen revisions in fourteen hips (22.9%) during the follow-up period, but no revisions were performed because of loosening of the acetabular component and no additional cups had loosened since the time of the last report at a minimum of ten years. Two components had previously been reported as loose and had migrated, but neither had been revised at the time of the latest follow-up. The minimum twenty-year follow-up of these cementless acetabular components demonstrated durable long-term fixation. The survival rate was 100% with revision of the shell because of aseptic loosening as the end point and 97.7% (95% confidence interval, ± 8.8%) with radiographic evidence of loosening as the end point. The authors continue to use cementless acetabular fixation with screw augmentation for most revision total hip arthroplasty procedures. Therapeutic Level IV.

Successful Long-Term Fixation and Progression of Osteolysis Associated with First-Generation Cementless Acetabular Components Retrieved Post Mortem

Primary cementless acetabular reconstruction has shown durable long-term fixation. Late failures secondary to aseptic loosening are rare but may occur in patients with previously well-fixed components. In the present study, the histopathological characteristics of postmortem specimens were correlated with wear damage and radiographic data in an attempt to better understand the long-term events in the periacetabular tissue around well-functioning devices. Seventeen primary cementless Harris-Galante I acetabular components with adjacent tissues were harvested after a mean of eleven years (range, four to twenty-five years) from patients whose implants were well functioning at the time of death. Undecalcified and paraffin sections were used to quantify the extent of bone and soft tissues within the porous coating and at the interface between the coating and the surrounding bone. Wear particles were identified with use of polarized light microscopy and energy-dispersive x-ray analysis. Bearing-surface volumetric wear and backside wear damage of the polyethylene liner were assessed. All of the components were fixed by bone ingrowth (mean extent, 33% ± 21%). Particle-induced granulomas were present in the porous coating and along the interface and progressed through screw holes, ballooning into the retroacetabular bone in the longer-term specimens. Particles of femoral and acetabular origin were identified in the granulomas. Bearing-surface volumetric wear (mean, 41.6 mm3/year) increased with duration and correlated with increasing extent of granuloma in the porous coating and the increasing size of pelvic granulomas. Radiolucencies on radiographs correlated with the extent of bone and fibrous tissue ingrowth. Of the six pelvic granulomas that were identified histologically, only one was apparent on routine radiographs. Acetabular fixation by bone ingrowth can be successful into the third decade after implantation. Osteolysis and secondary replacement of bone with particle-induced granuloma are commonly seen in the presence of excellent clinical function. Strategies designed to minimize bearing-surface wear and backside damage are important to maintain long-term bone ingrowth fixation.