In primary and revision total hip arthroplasty (THA), the acetabular component continues to pose greater challenges than the femoral component. Numerous factors lead to polyethylene wear, which subsequently affects primary THA survival. Progressive polyethylene wear is associated with the occurrence of osteolysis, especially overlying the acetabulum, which can lead to ...

The purpose of this study was to compare acetabular component positioning using an imageless system to a matched control group using conventional techniques. Thirty procedures were performed using navigation. A multislice computed tomographic scan was used to assess cup position. There was no significant difference between mean ...

The use of large metal on metal bearings has led to a reduction in the risk of dislocation post hip arthroplasty. Because of this, and also because of the technical difficulties associated with resurfacing surgery in particular, it could be argued that a less meticulous approach to acetabular cup placement has developed in comparison with conventional ...

ABSTRACT: BACKGROUND: Correct placement of the acetabular cup is a crucial step in total hip replacement to achieve a satisfactory result and remains a challenge with free hand techniques. Imageless navigation may provide a viable alternative to freehand technique and improve placement significantly. The purpose of this project was to assess and validate ...

BackgroundCorrect placement of the acetabular cup is a crucial step in total hip replacement to achieve a satisfactory result and remains a challenge with free-hand techniques. Imageless navigation may provide a viable alternative to free-hand technique and improve placement significantly. The purpose of this project was to assess and validate ...

Eighty-six polyethylene liners and 56 metallic shells of acetabular components were evaluated by visual and stereomicroscopic examination for impingement, backside polyethylene wear, creep, and fretting at the screw-metallic shell interface using a subjective scoring system. Medical records and radiological data were available in 65 and 46 patients, ...

Five different porous-coated acetabular prosthetic configurations underwent in vitro testing to assess mechanical stability in embalmed cadaver hemipelves: Harris Galante II cup with three cancellous screws, Biomet Universal cup, Whiteside cup with peripheral pegs, Whiteside cup with two ...

The study uses idealized two-dimensional finite element models to examine the behaviour of the acetabular construct following revision hip arthroplasty, carried out using the Slooff-Ling impaction grafting technique. The behaviour of bone graft was considered in detail, with non-linear elasticity and non-associated plasticity being adopted. Load was applied to the ...

BackgroundContact pressure of UHMWPE acetabular cup has been shown to correlate with wear in total hip replacement (THR). The aim of the present study was to test the hypotheses that the cup geometry, abduction angle, thickness and clearance can modify the stresses in cemented polyethylene cups.MethodsAcetabular ...

The aim of the study was to analyze early results of total uncemented hip replacement with use of small diameter acetabular components. In the group of 13 patients (15 hips) with severe dysplastic coxarthrosis mean age at surgery was 43.6 years. There were 8 right and 7 left hips operated. For clinical assessment Merle d'Aubign� and Postel classification modified by Charnley ...

BackgroundWe performed a retrospective study to evaluate the results of acetabular circumferential medial wall osteotomy, a procedure designed to provide secure fixation of a cementless hemispherical acetabular cup for the sequelae of septic arthritis of the hip.MethodsWe assessed 38 total hip arthroplasties (THAs) with circumferential ...

A review of current clinically applied biomaterials for the femoral heads and acetabular cups of total hip prostheses (UHMWPE, CoCrMo alloys, alumina and zirkonium) in terms of their resistance to wear is presented. Further developments in metallic and ceramic materials over the last few years have now left UHMWPE as the weakest link in the prosthesis ...

Resurfacing systems use press-fit, monoblock, cobalt chrome alloy acetabular sockets because of the material's ability to withstand stresses while accommodating a large femoral head. Despite the widespread use of these types of sockets for both hip resurfacing and total hip replacement, there is a paucity of literature assessing the outcomes of these ...

INTRODUCTION: Revision surgery in patients showing polyethylene wear and acetabular osteolysis without visible acetabular cup loosening involves the difficult decision of whether to revise only the liner or both the cup and the liner. The purpose of this study is to compare the outcomes of complete ...

A major concern during revision hip arthroplasty is acetabular bone loss and bleeding during the extraction of well-fixed cementless acetabular cup, because no interface exists between the host bone and the cup. Forceful removal of such component using curved gouges and osteotomes often leads to extended bone loss ...

Appropriate anatomic concepts for surgery to treat femoroacetabular impingement require a precise appreciation of the native acetabular anatomy. We therefore determined (1) the spatial acetabular rim profile, (2) the topography of the articular lunate surface, and (3) the 3-D relationships of the acetabular opening plane comparing 66 ...

Ensuring the stability of a cemented PROSTALAC cup (Depuy, Warsaw, Ind) in the presence of severe superior acetabular segmental deficiency is critical to the success of the first-stage surgery. We present an illustrative case and the surgical technique required to achieve this. PMID:21752577

Infra-red measurement systems are an established facet of operative procedures using surgical navigation, yet questions remain regarding their accuracy and everyday suitability. The importance of these systems has grown with the increasing popularity of minimally invasive procedures, which are associated with a reduction in operative field visibility. Even ...

BackgroundThere are multiple revision implant systems currently available for socket revision in revision total hip arthroplasty. Up until now, not all of these systems have been followed up with regards to their long-term use as a revision implantation.For the first time, this study presents the hemispherical porous-coated socket Plasmacup SC, produced by ...

At 10 years, we reported survivorship of the Omnifit hydroxyapatite-coated femoral stem and the Omnifit-PSL porous-coated dual-radius acetabular shell (Stryker, Mahwah, NJ) with polyethylene liners sterilized by gamma radiation in air. Our 15-year follow-up examines survivorship and functional outcomes of this system. Ninety-two patients (98 hips) were ...

Five fresh cadaver pelves were cleaned of soft tissue and instrumented with strain gauges. The acetabula were reamed, and a cementless cup, oversized at the periphery, was inserted. The applied force and cup acceleration were measured during insertion and used to calculate an effective mass of the cup, insertion device, and pelvis ...

The aim of the research was to investigate the cemented bone-implant interface behavior (cement layer degradation and bone-cement interface debonding) with emphasis on imaging techniques suitable to detect the early defects in the cement layer. To simulate in vivo conditions a human pelvic bone was implanted with polyurethane acetabular cup using ...

The computed tomographic (CT) and conventional radiographic appearances of the acetabulum are correlated for assessment of acetabular fractures according to the Judet and Letournel classification system, a system widely used by orthopedic surgeons performing fracture reduction and external fixation of the acetabulum. A desiccated ...

An effective lubrication can significantly reduce wear of metal-on-metal artificial hip joints. The improvement of the lubrication can be achieved through the optimisation of the bearing geometry in terms of a small clearance and/or the structural support such as a polyethylene backing underneath a metallic bearing in a sandwich acetabular cup form. The ...

The purpose of this paper was to evaluate the results of acetabular revisions with the use of an oblong revision cup that is designed with its longitudinal diameter elongated relative to its transverse diameter. Between 1996 and 2001, 62 hips in 60 patients underwent an acetabular revision with the insertion of a LOR ...

Contact mechanics analysis for a typical McKee-Farrar metal-on-metal hip implant was carried out in this study. The finite element method was used to predict the contact area and the contact pressure distribution at the bearing surfaces. The study investigated the effects of the cement and underlying bone, the geometrical parameters such as the radial clearance between the ...

Fifty-three patients (54 hips) treated with cemented total hip reconstruction with the aid of an acetabular mesh made of Vitallium (Howmedica Inc., Rutherford, New Jersey), a cobalt-chrome molybdenum alloy, to reinforce the medial cement for deficient bone stock in the central acetabular region, were evaluated at an average follow-up period of 6.8 years ...

A radiographic study of a singular type of threaded cup, revised due to aseptic loosening, was performed with Einzel-Bild-Roentgen-Analyse (EBRA) to detect eventual risk factors and patterns of loosening. Fifty-three cups of 50 patients were revised. Forty-two cups could be measured with EBRA. No cup had obvious ...

The impact of femoral head surface roughness on wear of gamma-irradiation sterilized (3 MRad in nitrogen, crosslinked) and nonsterilized (not crosslinked) UHMWPE acetabular cups has been evaluated. Gravimetric wear testing was performed in a hip joint simulator for 2 x 10(6) cycles. CoCrMo heads were used with different surface roughness (R(a) = 15 nm and ...

PURPOSE: Correct cup positioning is one of the keys for successful total hip replacement. There are mechanical and computer assistant guides for correct cup positioning in the market. To optimize the cup positioning, the use of navigation systems is recommended. The aim of this study was to compare spatial ...

The purpose of the study was to investigate the contact stresses in 3 different acetabular cup rim designs (new, worn, chamfer) during edge loading, after microseparation of ceramic on ceramic hip prostheses. A 3-dimensional finite element analysis was conducted for a 28-mm diameter alumina ceramic bearing with a radial clearance of 40 ?m using a normal ...

Ultra-high molecular weight polyethylene acetabular cups of 5 different total hip systems (M�ller, Mallory-Head, Lubinus, P.C.A. and Charnley-Elite) were worn on a new 5-station hip joint simulator. The cups articulated against modular metallic (stainless steel in M�ller and Charnley-Elite, ion-implanted ...

The major failure mode of cemented or noncemented acetabular fixation is osteolysis produced by biologic reaction to polyethylene and metallic debris. A monoblock acetabular noncemented component offers advantages in reducing the failure mechanism of acetabular cups. First, there is no extra-articular back surface ...

Total hip joint arthroplasty is commonly used in cases of osteoarthritis and rheumatoid arthritis. A hip joint prosthesis consists of a cup and a stem. The relative pose (position and orientation) of the prosthesis, when the patient is standing naturally, is planned pre-operatively; however, there is no guarantee that the pre-operatively planned pose will be accurate. ...

Followed by successful demonstration of high interfacial tensile strength in a new design of cemented all-polyethylene acetabular cup, interfacial shear strength was investigated in this study, with the use of canine-size prototypes of polymethylmethacrylate (PMMA) precoated UHMWPE acetabular cups. In addition to ...

We reviewed 81 consecutive ABG I primary total hip replacements implanted in 72 patients between January 1993 and December 1998. The mean follow-up was 8.2 (range 7-12) years. There was significant polyethylene wear and osteolysis associated with the acetabular cup . The cumulative survival of the cup with revision being the end point ...

Cementless acetabular components are routinely used in revision hip surgery. Nevertheless, few investigators have assessed their retention and efficacy over the long term. This occurs mainly in cases which originate from moderate to severe bone losses (cavitary and or segmental) requiring the use of morselized and or bulk bone graft. Our objective in the present study is to ...

In a prospective and randomised clinical study, we implanted acetabular cups either by means of an image-free computer-navigation system (navigated group, n = 32) or by free-hand technique (freehand group n = 32, two drop-outs). Total hip replacement was conducted in the lateral position and through a minimally invasive anterior ...

This is a prospective review of 135�HA-coated ABG I total hip arthroplasty (THA) systems with a mean clinical and radiographic follow-up of 8.5�years. The 5-year survival rate was 85%, but 22% of the patients were dissatisfied. Revision THA was already indicated in 28% of the patients, with 26% indicated for cup loosening. PE wear was detected by x-ray ...

This paper explores the effect of under-reaming on micromotion at the cup/bone interface of a press-fit acetabular cup. A cadaver experiment was performed on 11 acetabuli implanted with a cementless acetabular cup. The loading profile simulated hip impingement at the extremes of motion and ...

A finite element model has been developed to predict in vivo micro motion between a modular acetabular cup and liner after cement less total hip arthroplasty. The purpose of this study is to experimentally validate the model. Six LVDT sensors were used to monitor the micromotion of the liner when subjected to loading conditions ranging from 250 N to 5000 ...

The theoretical advantage of using thinner acetabular components in hip resurfacing has not yet been clinically verified. Our purpose was to test the hypothesis of bone conservation and assess the effects of using a thinner acetabular component on hip biomechanics and clinical outcome. We compared the bone conservation, biomechanical results, and ...

The authors propose a simple and practical method to measure radiologically the angle of ante- or retroversion of the acetabular cup using a goniometer. It only necessitates an anteroposterior radiograph centered on the femoral head and another one centered on the public symphysis. Special x ray equipment, compass, conversion table, mathematical formulas, ...

Orthopaedic surgeons must currently choose from several types of ultra high molecular weight polyethylene acetabular cups that differ in their material properties and in the methods used for their sterilization. Information on the wear resistance of these different cups may help in the selection process. This study included two ...

Hip resurfacing is femoral bone preserving, but there is controversy regarding the amount of bone removed at the acetabular side. We therefore compared the implanted acetabular cup sizes in primary THAs between two resurfacing devices and a conventional press-fit cup using a series of 2134 THAs ...

We report the results of 24 acetabular reconstructions in which cemented polyethylene cups and tamped corticocancellous allografts were used for severe acetabular bone deficiency. Eleven hips had type-II (cavitary) bone deficiency and 13 had type-III (combined) defects. At a mean follow-up of 5.8 years, two components had migrated more ...

In view of the controversy about bulk autografts to provide support for the acetabular cup in reconstruction of the dysplastic hip, a series of 15 dysplastic hips were investigated as follows: Femoral head autograft shelf reconstruction and cemented acetabular components were evaluated at an average follow-up period of 99 months after ...

BackgroundIt has been indicated that, in the long term, the rate of wear and the degree of osteolysis observed with uncemented acetabular components are greater than those associated with cemented cups, but most studies which compare the wear characteristics of cementless with cemented cups have used historical controls. We report a ...

This article summarises a clinical and radiographical analysis of 30 acetabular revisions in patients younger than 55�years old, performed with impaction bone grafting and cemented cups. Preoperative Merle D�Aubigne and Postel functional score was an average 7 points. At a mean follow-up of 86.5�months (range 34�228) functional score averaged 16.3 ...

BackgroundLoosening of acetabular components often leads to bony defects. Management of extensive acetabular bone loss in hip revision arthroplasty can be a tremendous challenge.Questions/purposesWe asked whether a reconstruction with impacted bone grafts will provide a durable and pain-free function in extensive acetabular defects. We ...

Massive acetabular bone loss (more than 50% of the acetabular area) can result in insufficient native bone for stable fixation and long-term bone ingrowth of conventional porous cups. The development of trabecular metal cages with osteoconductive properties may allow a more biological and versatile approach that will help restore bone ...

We report a case of a 46-year-old male patient who sustained a fracture of the Burch�Schneider anti-protrusio cage (APC) that was implanted 13 years before. The fracture occurred in the transitional area to the proximal flange and was caused by direct and recurrent contact between the prosthetic metal head and the acetabular device. Late failure was related to increased wear ...

Alumina ceramic-on-ceramic total hip arthroplasty (THA) has been widely used due to its advantages such as low wear, scratch resistance, wettable surface and relatively low biological reactivity of the wear particles. Nevertheless, this material in THA still persists to be one of the major concerns about the risk of fracture, due to its brittleness. Many authors have reported a fracture of the ...

A subject-specific three-dimensional finite element (FE) pelvic bone model has been developed and applied to the study of bone-cement interfacial response in cemented acetabular replacements. The pelvic bone model was developed from CT scan images of a cadaveric pelvis and validated against the experiment data obtained from the same specimen at a simulated single-legged ...

BACKGROUND: The recent interest in hip resurfacing arthroplasty is motivated by its potential advantages over THA. One advantage of hip resurfacing arthroplasty is that it conserves bone on the femoral side; however, it is unclear whether it does so on the acetabular side. QUESTIONS/PURPOSES: We determined whether the amount of acetabular reaming and ...

PURPOSE. To evaluate long-term outcomes of total hip arthroplasty (THA) using the Perfecta cementless system. METHODS. 73 men and 76 women aged 65 to 88 (mean, 71) years underwent 168 THAs using the Perfecta cementless system and were followed up for a mean of 13 (10 to 15) years. 19 patients had bilateral THA. The diagnoses were idiopathic osteoarthritis ...

Implantation of a cementless press-fit acetabular cup during hip arthroplasty alters stress transfer to the periacetabular bone, resulting in stress shielding of cancellous bone and enhanced load transfer to cortical bone. Theoretically, the thicker, stiffer and larger acetabular cup of a hip resurfacing may ...

The purpose of the present study was to evaluate the 6- to 11-year follow-up results of hemispherical porous-coated cups implanted into dysplastic hips using press-fit technique without screws focusing on the amount of host bone coverage. There were 87 patients who underwent 98 primary total hip arthroplasties. Bony coverage was measured as the angle between the vertical line ...

We aimed to investigate the transfer of metal to both ceramic (alumina) and metal (cobalt-chrome) heads that were scraped by a titanium alloy surface under different load conditions. The ceramic and metal heads for total hip arthroplasties were scraped by an acetabular metal shell under various loads using a creep tester. Microstructural changes in the scraped area were ...

In a multifoil thermal insulation package having a plurality of concentric cylindrical cups, means are provided for reducing heat loss from the penetration region which extends through the cups. At least one cup includes an integral skirt extending from one end of the cup to intersection with the penetration means. ...

Ultra-high molecular weight polyethylene acetabular cups backed by Ti-6Al-4V acetabular shells were articulated against Co-Cr-Mo alloy, ion-implanted Co-Cr-Mo alloy, and zirconia ceramic femoral heads in a hip joint simulator. Three tests of three million walking cycles each were run with five different head-cup ...

BackgroundHydroxyapatite (HA) is the main inorganic component of bone, and HA coating is widely used on acetabular cups in hip arthroplasty. It has been suggested that this surface finish improves cup survival.MethodsAll patients registered in the Swedish Hip Arthroplasty Register between 1992 and 2007 with an uncemented ...

Squeaking of hip replacements with ceramic-on-ceramic bearings has put the use of this material into question despite its superior wear behavior. Squeaking has been related to implant design. The purpose of this study was to determine the influence of particular acetabular cup and femoral stem designs on the incidence of squeaking and its characteristics. ...

The Exeter� Universal hip (Stryker Inc., Newbury, UK) has reported survival rates of 91.74% at 12�years in all patients with reoperation as an endpoint. However, its performance in younger patients has not been fully established. We reviewed survivorship and the clinical and radiographic outcomes of this hip system implanted in 107 patients (130 hips) 50�years old or ...

Five patients presented with fiber metal mesh shedding of a Harris Galante II acetabular cup detected between 11 and 15 years after implantation. All patients presented with hip pain and 4 demonstrated gross acetabular loosening and fiber metal separation on preoperative radiographs. The remaining patient underwent revision surgery ...

The success of metal bearings is dependent on several parameters. The effects of in vivo forces on the deformation of monoblock acetabular components have yet to be determined. The purpose of our study was to assess the amount of deformation with press-fit fixation of 1-piece metal acetabular components. Four manufacturers provided 1-piece metal ...

We applied a Raman confocal spectroscopic technique to quantitatively assess the structural features of two kinds of acetabular cups made of ultra-high molecular weight polyethylene. We wanted to know whether polyethylene cups belonging to different generations, and thus manufactured by different procedures, possess different molecular ...

IntroductionRevision acetabulum arthroplasty is one of the common procedures, which has been on the rise recently. Many implants are available in the market with variable results. Aseptic loosening is the most common indication for revision acetabulum arthroplasty. Birmingham dysplasia cup has been used occasionally in these complex procedures. We know that these implants have ...

The anatomic femoral component and Harris-Galante porous II (HGPII) cup were developed to provide more reliable bone ingrowth. We performed 20 cementless total hip arthroplasties (THAs) with anatomic stem/HGPII cup with 22-mm head in 14 consecutive patients, and evaluated the clinical and radiological results for a mean follow-up of 12.8�years. The ...

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In case of major bone loss, where <50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring or cage in association with a cemented component and allograft bone should be ...

Two methods were developed and evaluated for cross-linking the bearing surface of a polyethylene acetabular cup to a limited depth, in order to improve its resistance to wear without degrading the mechanical properties of the bulk of the component. In the first method, low-energy electron beams were used to cross-link only the bearing surface of the ...

BackgroundCotyloplasty is a technique that involves making a perforation of the medial wall of a shallow acetabulum and then inserting an acetabular cup with the medial aspect of its dome beyond the Kohler line. The purpose of this study was to evaluate the results of cementless total hip arthroplasty (THA) using cotyloplasty with focusing on the amount of ...

Taguchi technique is a powerful method of solving engineering problems in order to improve the performance of a process and to enhance the productivity. The methodology for the design of the experiment is proposed in order to find the best parameters for better experimental results with less number of experiments as possible. In this study, Taguchi technique was applied to optimize the compression ...

A custom-made hip is essential for the initial stability and longevity which correspond to an optimal stress distribution, since a standard hip cannot always satisfy every patient's need. In order to find out the designing principles of a custom-made hip, a patient's personal features on which the design was based were acquired. In this study, an integrated finite element model of the hip ...

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 ...

Between March 1990 and May 1991 we performed 85 primary total hip replacements in 74 patients using the Landos Atoll hydroxyapatite (HA)-coated cup and the Corail HA-coated stem. The patients were followed up for a mean of ten years. Of the 85 cups, 26 (31%) have already been revised and a further six are radiologically unstable and awaiting revision. Two ...

Total joint replacements (TJRs) have a limited lifetime, but the introduction of components that exhibit good lubricating properties with low friction and low wear could extend the life of TJRs. A novel acetabular cup design using polyurethane (PU) as a compliant layer (to mimic the natural joint) has been developed. This study describes a series of ...

There are no clear explanations for the spectrum of hip dysplasia nor for the observation that in normal and dysplastic hips, final development may be unpredictable with or without treatment. Immunohistochemical and histological studies of a three month old child's acetabulae were performed. Multiple inclusions were found in the lateral ring epiphysis and in the three flanges of the triradiate ...

Impaction grafting is controversial in the presence of segmental and cavitary acetabular defects and requires the use of supplemental devices to close segmental defects. This approach, however, would allow treating combined deficiencies that could not be managed with impacted cancellous bone alone. We raised the following two questions: (1) What is the survival rate in ...

OBJECTIVES:Our primary aim was to compare the long?term survivorship rates and the rates of successful osseointegration between two different types of uncemented acetabular components.INTRODUCTION:Two types of alloys have primarily been used for the manufacture of the uncemented acetabular components: titanium?based and cobalt?based alloys. A ...

Although there is a great deal in the literature about the clinical accuracy of computed tomography (CT)-based navigation systems for acetabular cup orientation and leg length discrepancy in total hip arthroplasty, there is little analysis of femoral stem orientation. Thirty total hip arthroplasties in which CT-based navigation ...

Metal press-fit cups and shells are widely used in hip resurfacing and total hip replacement procedures. These acetabular components are inserted into a reamed acetabula cavity by either impacting their inner polar surface (shells) or outer rim (cups). Two-dimensional explicit dynamics axisymmetric finite element models were developed ...

Objective: In order to achieve accurate implantation of the acetabular prosthesis in total hip arthroplasty (THA), we designed individual templates based on a three-dimensional (3D) model generated from computed tomography (CT) scans. Methods: Individual templates were designed for 12 patients who underwent THA. A physical template was designed to conform to the contours of ...

Squeaking in total hip arthroplasty (THA) has been observed only in hard-on-hard bearings, such as ceramic-on-ceramic or metal-on-metal. We report the case of a patient with a squeaking THA who had undergone multiple femoral head revisions combined with a composite ceramic cup (polyurethane, ceramic). Squeaking started 6 years postoperatively and ...

In a multifoil thermal insulation package having a plurality of concentric cylindrical cups, means are provided for reducing heat loss from the penetration region which extends through the cups. At least one cup includes an integral skirt extending from one end of the cup to intersection with the penetration means. ...

Using computed tomography-assisted (CT) osteodensitometry, we studied the bone changes that occurred in 12 patients at 2 weeks and again at 1 year after total hip arthroplasty with insertion of a press-fit acetabular cup and an uncemented femoral tapered stem. There was a greater decrease in full bone density (BD) lateral to the femoral stem when compared ...

Joint simulators are important tools in wear studies of prosthetic joint materials. The type of motion in a joint simulator is crucial with respect to the wear produced. It is widely accepted that only multidirectional motion yields realistic wear for polyethylene acetabular cups. Multidirectionality, however, is a wide concept. The type of ...

In the 1970s, high failure rates of cemented acetabular components, especially in young patients, in the middle- and long-term prompted a search for alternatives. The Mecring was one of the most popular first generation uncemented, threaded cups widely used in the 1980s for arthroplasty of the hip. First generation threaded cups ...

Factors that influence the outcome of acetabular replacement are design materials, means of fixation, operative technique, and patient-related parameters (e.g., etiology of osteoarthrosis). Whereas improved cementing techniques have produced a marked reduction in the rate of femoral component loosening, the incidence of acetabular loosening has been only ...

BACKGROUND: The recommended range of anteversion of the components in total hip arthroplasty (THA) is between 10 and 30�, but the intraoperative estimation of these versions may be inadequate. HYPOTHESIS: The components anteversion in primary cementless THA using straight stem and hemispherical cup is not significantly different from the native anteversion of the hip joint. ...

The total penetration of femoral heads into acetabular cups is achieved by a combination of long-term wear and early non-recoverable deformation or creep. The former is important in determining the total rate of production of polyethylene wear debris, recently implicated in the development of osteolysis and loosening, while the latter contributes to the ...

Wear of the polyethylene in total joint prostheses has been a source of morbidity and early device failure, which has been extensively reported in the last 20 years. Although research continues to attempt to reduce the wear of polyethylene joint-bearing surfaces by modifications in polymer processing, there is a renewed interest in the use of metal-on-metal bearing couples for hip prostheses. Wear ...

Recent in vitro work has shown that sealing the acetabular notch with bone graft in bovine acetabulum samples results in improved cement penetration in the acetabular bone during total hip arthroplasty. Successful sealing of the notch may be identified on postoperative films by a lack of cement extrusion. This study aimed to assess the clinical ...

Quantifying soft-tissue tension around the hip joint during total hip arthroplasty remains difficult. In this study, a three-dimensional computer-aided design model was developed to clarify how component position in total hip arthroplasty contributes to the primary cause of posterior dislocation in cases of flexion, adduction and internal rotation. To better understand the influences of ...

Porous surfaces are intended to enhance osteointegration of cementless implants. Tantalum has been introduced in an effort to enhance osseointegration potential of uncemented components. We therefore compared the clinical outcome of acetabular components with two different porous surfaces. We retrospectively reviewed 283 patients (295 hips) who underwent cementless revision ...

Hydrated polymer coatings on polymer substrates are common for many biomedical applications, such as tissue engineering constructs, contact lenses, and catheters. The thickness of the coatings can affect the mechanical behavior of the systems and the cellular response, but measuring the coating thickness can be quite challenging using conventional methods. We propose a new ...

In the present work, based on high frequency wavelet analysis of dynamic signals of mechanical systems, a multiple-resolution wavelet analysis is carried out, to the signal obtained from an accelerometer mounted on the structure of a hip prosthesis wearing test device. The prostheses employed had a femoral head made of aluminum oxide and the acetabular ...

Patients Receiving Primary Hip Arthroplasty Using the Continuum Metal on Polyethylene Acetabular System

... wear rate of prosthesis contact surfaces is greatly accelerated if loose fragments of bone cement become detached and act as an abrasive in the ...

... Panel meeting; Dr. Mayor reported that his laboratory has not received any CoMplete � Acetabular Hip System components for retrieval analysis. ...

Lead content has been determined in untreated urine by atomic absorption spectrophotometry using the Delves Cup micro-sampling system. Twenty microliters of untreated urine is added to a flame-cleaned Delves Cup, the Delves Cup is advanced until the cup i...

Polyetheretherketone (PEEK) is one of the up-to-date organic polymer thermoplastics with applications in orthopaedics and trauma medicine. This study presents a detailed analysis of its tests and applications in clinical medicine. A wide range of PEEK modifications and composites are commercially available, e.g., PEEK-Classix, PEEK-Optima, Endolign and Motis. They differ in their physical ...

The implantation of an endoprosthetic socket into the acetabulum alters the mechanical stresses in the periacetabular region in a significant manner compared with the natural hip joint. In this way, a remodelling process is initiated. Primary stability to achieve osseointegration and a loading of the acetabulum owing to the biomechanical interaction between cup and bone that ...

After total hip replacement (THR) impingement of the implant components causes shear stresses at the acetabular implant-bone interface. In the current study the finite element method (FEM) was applied to analyse the shear stresses at a fully bonded implant-bone interface assuming total ingrowth of the cup. The FE model of a press-fit ...

A new uncemented acetabular component, the Cambridge cup, has been designed to mimic the anatomy and physiology of subchondral bone in order to minimise stress shielding and enhance long-term component stability. Cambridge cups were implanted in a cohort of 50 women who presented with displaced sub-capital fracture of the femoral neck. ...

Intrapelvic acetabular cup migration is a rare but serious complication, which can occur after cup loosening following total hip arthroplasty. To make safe intrapelvic implant removal, several principles must be respected: identification of potential risks with a thorough preoperative workup, preoperative planing of a surgical strategy ...

High-porosity "cancellous metal" coatings have been introduced to increase the fixation and biologic incorporation of acetabular cups. The strength of initial fixation provided by a cancellous metal cups vs conventional alternatives in the deficient revision acetabulum was investigated. Cancellous, plasma-sprayed, and beaded ...

Small-diameter cemented Metasul� cups have been previously identified to be at high risk of early loosening. We asked whether this particular mode of failure was associated with a specific histological feature. Periprosthetic tissues were obtained at the time of revision of two aseptically loose cemented Metasul� cups. Each tissue sample was processed ...

, ISAAC and TEAMORE, for off�line review of RoboCup. Our response draws from these multiple systemsTwo Fielded Teams and Two Experts: A RoboCup Challenge Response from the Trenches Milind Tambe, Gal ftambe,galk,marsella,muslea,rainesg@isi.edu Abstract The RoboCup (robot world�cup soccer) ...

, ISAAC and TEAMORE, for off-line review of RoboCup. Our response draws from these multiple systemsTwo Fielded Teams and Two Experts: A RoboCup Challenge Response from the Trenches Milind Tambe, Gal tambe,galk,marsella,muslea,raines� @isi.edu Abstract The RoboCup (robot world-cup soccer) ...

The Rim Cutter (Stryker Orthopedics, Mahwah, New Jersey) is a tool designed to cut a ledge inside the rim of the acetabulum, onto which a precisely trimmed, cemented, flanged cup can be fitted. The aim was to investigate the effect of the Rim Cutter on the intra-acetabular cement mantle pressure and the depth of cement penetration during ...

INTRODUCTIONExtensive bone loss associated with revision hip surgery is a significant orthopaedic challenge. Acetabular reconstruction with the use of impaction bone grafting and a cemented polyethylene cup is a reliable and durable technique in revision situations with cavitatory acetabular bone defects. Some use cancellous graft ...

IntroductionMany kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics ...

wear de- bris which may accelerate loosening of implant bone interfaces. The position of im- pingement systems used in orthopaedics is the need for fiducial pins to be surgically implanted into bone before preDevelopment and Validation of a Navigational Guidance System for Acetabular Implant Placement* D

The centre of rotation of the hip can be displaced in hip dysplasia and revision arthroplasty. This study examined the effect of artificial femoral head load after acetabular component displacement in total hip arthroplasty. Sixteen total hip arthroplasty models of human cadaver specimens were reconstructed, and under different acetabular component ...

The centre of rotation of the hip can be displaced in hip dysplasia and revision arthroplasty. This study examined the effect of artificial femoral head load after acetabular component displacement in total hip arthroplasty. Sixteen total hip arthroplasty models of human cadaver specimens were reconstructed, and under different acetabular component ...

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 ...

Pelvic and acetabular injuries are rare and represent the tip of the trauma iceberg. They often present with other associated injuries. Their management can pose difficulties even to the most experienced trauma surgeons and well-developed trauma systems. Despite the advancements made after the 1960s due to Judet and Letournel's contributions, the pelvic ...

DOP-26 iridium alloy cups are used for fuel cladding for radioisotope power systems. The cups are deep drawn and recrystallized prior to final fabrication operations. This study characterizes the plastic deformation of cups during a sizing operation following the recrystallization heat treatment. The purpose of the ...

... During valve closure, the disk protrusion enters the cup depression forcing water in the depression to exit the cup through a primary restrictive path ...

... cup anemometers, including data registers, were CW Thornthwaite Associates Wind Profile Recording System Model 106. The anemometer cups ...

There are six different definitions of acetabular position based on observed inclination and anteversion made in either the (1) anterior pelvic plane or (2) coronal planes and based on whether each of the observations made in one of these two planes is (1) anatomic, (2) operative, or (3) radiographic. Anteroposterior pelvic tilt is the angle between the anterior pelvic plane ...

The complications, management, and outcome of a consecutive series of 61 ilioischial reconstruction rings performed by 1 surgeon over a 15-year period are reported. Structural corticocancellous allografts were used in 48 cases. Twenty-seven cases had no complications, 9 had medical complications, and 5 had complications related to femoral revision. Other complications included 4 sciatic and 2 ...

The versatility of modular total hip arthroplasties have rapidly extended their applications. However, these new interfaces can lead to complications that were not observed with monolithic components. These problems have been noted with modular femoral and acetabular components and have been associated with the generation of particulate debris. This article reviews the ...

The main design features of metal-on-metal (MOM) hip resurfacing prostheses in promoting elastohydrodynamic lubrication were investigated in the present study, including the femoral head diameter, the clearance, and the cup wall thickness. Simplified conceptual models were developed, based on equivalent uniform wall thicknesses for both the cup and the ...

Total hip arthroplasty (THA) still carries a higher failure rate in patients with avascular necrosis of the femoral head (AVN) than in a similar patient population with THA for other reasons. This is particularly true for the acetabular component. One of the major factors accounting for this is the compromised acetabular bone quality with structural ...

Knowledge of the acetabular rim and surface can be invaluable for hip surgery planning and dysplasia evaluation. The acetabular rim can also be used as a landmark for registration purposes. At the present time acetabular features are mostly extracted manually at great cost of time and human labor. Using a recent level set algorithm ...

In the area of orthopaedic implants, particularly total hip joint replacements, a metal-plastic combination is still the most popular choice consisting of a femoral head fabricated from 316L stainless steel, Ti alloy or Co-Cr alloy in contact with an ultra-high molecular weight polyethylene (UHMWPD) acetabular cup. It is recently considered that wear of ...

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 ...

While favorable tribological properties and allowance for larger femoral head sizes have made metal-on-metal (MoM) bearings an increasingly popular choice for total hip arthroplasty, concerns have mounted regarding adverse reactions to metal wear debris and ions. MoM cups differ from conventional polyethylene cups in terms of edge profile design and ...

A technique for primary uncemented total hip arthroplasty in the presence of a superolateral acetabular deficiency is described. The resected femoral head is used as an autograft. Matching reamers are used to ream the pseudoacetabulum and femoral head. Lag screw fixation is then performed and reaming of the graft and host bone simultaneously allows placement of an uncemented ...

Bone stock deficiency presents the major challenge in acetabular reconstruction during revision hip arthroplasty. The preoperative assessment of acetabular bone stock before revision surgery is critical because the amount and location of pelvic osteolysis can determine the type and success of revision surgery. Traditionally, plain radiographs with AP and ...

The study investigates the short-term behaviour of the acetabular construct following revision hip arthroplasty, carried out using the Slooff-Ling impaction grafting technique; using 3D finite element analyses. An elasto-plastic material model is used to describe the constitutive behaviour of morsellised cortico-cancellous bone (MCB) graft, since it has been shown that MCB ...