Introduction and Aims: Polyethylene wear continues to be the most significant issue following total hip arthroplasty (THA), leading to the current increase in use of alternative bearing surfaces. We performed a prospective, randomised, blinded clinical trial comparing
Purpose of Study:. To look at the difference in
Purpose of the study:. Recent literature raised concern on the adverse effects, incidence of pseudo tumours and raised blood and urine Chromium and Cobalt levels in patients with a
Introduction. The aim of this study is to report the results of Revision hip arthroplasty using large diameter,
Introduction. Cemented stems have shown 90–100% survivorship when coupled with polyethylene acetabular component. This study aims to compare cemented stem behaviour in combination with large
Summary. The M2a-38. tm.
One hundred fifty one total hip arthroplasty (THA) with metal on metal hip system of without cement were followed at a mean of 5. 5 years (range 2. 6 years to 7 years). Original diseases were 134 hip in 123 cases with osteoarthritis and 17 hips in 13 with rheumatoid arthritis. The average Harris hip score of before the operation was 45. 3 points and at the follow-up time the average score was 88. 5 points. Radiographic findings in the incidence of partial radiolucent line around the component: in the acetabular component, no radiolucent line was observed, in the femoral component, marginal lucent lines were 8. 6% (13 hips). Cortical hypertrophy was observed in high ratio of 27. 2%(41 hips). There was no loosening and tilt of component over 5 degrees observed in any patient. Postoperative dislocation of the hip was observed 9 hips (6. 0%). Cobalt concentrations and chromium concentration in the serum were measured in cases in
Aims: A polyethylene free,
Fracture of the acetabulum can lead to degenerative arthritis of the hip, avascular necrosis of the femoral head, or both. Total hip arthroplasty is a common form of surgical treatment when significant joint changes and pain are present. Ten patients with fracture acetabulum were treated in this study using
Introduction. To report the short to medium term results of acetabular reconstruction using reinforcement/reconstruction ring, morcellised femoral head allograft and cemented
In a cross sectional cohort study three different
Ninety-four hips with a mean patient age 34.2 (range 15– 40) with a
Retrospective analysis of 25 consecutive
Background:
Patients with DDH are known to be at risk of early degenerative changes to their hips. To date, no consensus exists as to the most appropriate management of this group, with many surgical options being associated with specific complications such as dislocation and early wear. In addition, modern resurfacing methods are considered by many to be contra-indicated in patients with DDH due to the technical difficulty of the procedure. This prospective study analyses a single surgeon series of known DDH hips that underwent
Purpose. To evaluate the radiological changes after
Introduction: Disagreement exists in the literature as to whether hip resurfacing requires more acetabular reaming than uncemented hip replacement. Materials and Methods: Thirty-nine patients underwent total hip arthroplasty with a large
The poor outcome of large head
The poor outcome of large head
In-vitro studies have shown that wear rates of the
Medical and Health care products Regulatory Agency (MHRA) released an alert in 2010 regarding
The ‘first generation’
Introduction: The wear particles produced from the metal-on-metal hip prosthesis causes measurable rise of
Aims: Measure serum chromium (SrCr) and cobalt (SrCo) and urine chromium (UCr) levels in patients with
Introduction. We conducted independent wear analysis of retrieved
The poor outcome of large head
Introduction: Several studies have shown the presence of cobalt (Co) and chromium (Cr) ions in blood, urine, and organs of patients after THA using Co-Cr alloy-based implants. Even though it is well known that exposure to heavy
Introduction: Local problems of
This study reports the mid-term results of a large bearing uncemented
Introduction: The advantages of
This study reports the mid-term results of a large bearing hybrid
This study reports the mid-term results of a large bearing hybrid
In vivo and in vitro studies of ceramic on ceramic (COC) bearings have demonstrated that swing phase microseparation followed by the impact of the femoral head on the superior acetabular insert rim leads to accelerated wear. However, resultant wear remained low. The wear of ceramic on polyethylene (COP) and
Background: There is a paucity of published data with regard to the wear of failed
Retrieval analysis offers a direct insight into in vivo wear mechanisms. However, the 3D measurement of wear patch characteristics on spherical highly reflective bearings has been difficult. An instrument based on an optical technique has been developed over the past 3 years. It is capable of scanning metallic head and cup in a single measurement, within minutes, at a resolution of 20 nm. From the cloud of 3D points obtained during scanning (typically 35,000 To 1,000,000), a 3D image of the measured part can be obtained. The associated computer program allows for sphericity, roughness, radius and local radius to be calculated, and surface maps of the 3D model can easily be plotted. Both head and cup of two failed MoM resurfacing devices, a wear simulator test couple and intact components were analysed using the new technique. A successful McKee Farrar head (20 years in vivo) was also scanned. Results were compared with traces obtained on a Mitutoyo RA 300 roundness machine (resolution 0.01 microns). 3D maps of the bearing surfaces of MoM devices were obtained. The maximum linear wear values on heads were 2.5 microns, 99 microns 53.5 microns and 298 microns for the simulator sample, the McKee Farrar head and the two failed resurfacing devices respectively. The corresponding maximum linear wear values on cups were 11 microns, 529 microns and 645 microns for the simulator sample and the two failed resurfacing devices respectively. These results were in good agreement with results obtained on the Mitutoyo machine. Contrary to other worn samples, the two latter cups showed that the cup had worn on the edge of the bearing surface. This resulted in an oval shaped wear patch on the head. For the McKee Farrar device and the simulator device, the wear patch was away from the edge and the outline of the wear patch was circular in shape. This novel technique has allowed for high resolution 3D mapping of the full bearing surfaces on successful McKee Farrar device and on more recent resurfacing devices. Further studies are required. However, the results suggest that component positioning is paramount to wear performance of
The authors report their preliminary experience with a minimum of one year follow –up of hydroxyapatite coating as the means of fixation of the femoral head in hip resurfacing. Between Dec 2003 and Dec 2004, of the 23 cases performed by the senior author,22 were available for follow up,15 were women (68.2%) and 7 were men (31.8). The femoral and acetabular components of the uncemented version of the CORMET 2000(Corin,Cire ncester,UK) were used. The surgical approach was the Hardinge approach in all cases. Patients were assessed pre-operatively for pain and function,using the Harris Hip Score. Post operatively they were assessed in clinic with x rays at 6 weeks,6 months and annually thereafter. X rays were evaluated for pre and post op neck shaft angle,giving an indication of varus or valgus placement of the head prosthesis. The lateral view was assessed to reveal anterior or posterior tilting of the prosthesis. Neck thinning was evaluated by measuring the ratio of the
The purpose of this study is to identify clinical and radiographic results of 78 uncemented total hip arthroplasties using Metasul. ®.
The purpose of the present study was to analyze the-clinical and radiographic factors which determine the enduring fixation of
Background. Previous studies have suggested that the modular junction of
Introduction. The biological pathways responsible for adverse reactions to
Using a femoral head from one manufacturer on the stem of another manufacturer poses the risk that the taper interface between the components do not contact correctly and the performance of the joint will be impaired. The cohorts in this study are a combination of modular Birmingham Hip Resurfacing (BHR) and Adept femoral heads on CPT stems. The study reviews the geometry of the taper interfaces to establish if the taper clearance angles was outside of the normal range for other taper interfaces. In addition the rates of material loss from the bearings and taper and a ranking of the stem damage were reviewed to determine if the levels of loss were above that seen for other similar joints. The material loss analysis demonstrated that the rates or levels of loss from the bearings, taper and stem are no different to levels published for manufacturer matched joints and in many cases are lower. The results demonstrate that the taper clearance angles for the mixed manufacturer joints (BHR-CPT: 0.067 to −0.116, Adept-CPT: 0.101 to −0.056) were within the range of other studies and manufacturer matched clearances (0.134 to −0.149). Using components from different manufacturers has not in this instance increased the level of material loss from the joints, when compared to other similar manufacturer matched joints.
On hundred and ninety unselected patients, mean age 62(SD12.8) were operated upon by one surgeon, using same approach. HSS improved from 33 to 75 post-operatively, the low figures reflecting a high percentage of Charnley C patients (71%). There was a 5% mortality rate from unrelated causes. Early complications included a 2.97% femoral fracture rate within 4–8 weeks of surgery (analysis showed no relation between implant position, BMI, age or Charnley classification, but there was correlation between high level of satisfaction and early weight bearing). There was one infection and one dislocation. Late complications included 3 periprosthetic fractures, 3 dislocations and 2 aseptic cup failures. However, 30% of patients developed groin pain, increasing stiffness and clunking at 1–2 years following surgery. These patients were investigated with an ultrasound scan. 28 patients (14%) had an effusion and were aspirated. Chrome and cobalt levels in synovial fluid, blood and urine were very high. 13 patients have been revised. 1 showed infection, 10 showed
The awareness of MoM hips in the general public, one would expect, to be good, given the media coverage. This study aims to look at the perceptions and knowledge of patients who have already got a MoM arthroplasty. All the patients who have had a MoM hip arthroplasty from Nov 2003 to the end of 2007 were identified from the database. Postal questionnaires were sent to all the patients, the responses received and analyzed. Those patients who had symptoms and those who fulfilled MHRA criteria were invited to a clinic for further surveillance.Introduction:
Methods:
Introduction:
Introduction. Metal on metal hip bearings (MoM) are under scrutiny. Short and mid-term complications attributed to
There is increasing worldwide interest in the assessment of wear in explanted hip components. This is due is part to high profile failures of orthopaedic components in the US, whilst in the UK hip resurfacings have been experiencing a higher than expected failure rate. The reasons for these failures are not well understood, with data from the NJR suggesting the 43% of MoM resurfacing failures are unexplained. Wear analysis is a vital tool in determining failure mechanisms and ultimately improving the longevity of joint replacements through improved design and manufacturing control. There are currently no relevant measurement standards for the evaluation of retrieved orthopaedic components. This paper will assess two of the most commonly used techniques namely roundness measurement and co-ordinate measurement. The advantages and disadvantages of both techniques are considered in this paper. The Talyrond 365 is a stylus based roundness machine. The component is located on a rotating table and the stylus measures the deviation from a perfect circle as the component is slowly rotated. The Talyrond measures a single profile to an accuracy of 30 nm and up to 72,000 data points per revolution. The air spindle has a radial accuracy of <0.02 μm and the Talymin gauge a minimum resolution of 12 nm. Individual roundness profiles can be stitched together to build up 3D cylinder maps, allowing 3D pictures of sections of explanted hip components to be generated.INTRODUCTION
ROUNDNESS MACHINE
The pathologies of the hip (epiphisiolysis, Perthes, congenital dysplasia) cause invalidating outcomes in young patients. In the years many authors searched for the golden standard if total hip arthroplasty is necessary. From Smith-Petersen to McKee, to Amstutz the saving of the femoral neck has been the main objective, with the longevity of the system. Therefore the combination metal-metal has been used for articular components, because the friction of metallic components creates sub-micron metallic particles causing only minimal foreign body reactions andvery low wear rates. Our study group (Arthro Surgery Group) has implanted, from April 2003, 28 cementless resurfacing hip prosthesis with metal-metal articular components. The average follow-up has been of 6 months (from 3 months to 1 year). In all cases, the Harris Hip Score has been good or excellent (from 77 to 100), and radiographic exams didn’t show signs of radiolucence or resorption. This type of prosthesis allows moreover an minimum-invasive approach to the hip and a second line of defense in case of revision.
Ion analysis has been used as one of the key indicators to assess the performance of MoM devices in patients. Modular devices, in particular having larger overall surface area (the stem and sleeve), and locking interfaces (head – bore, sleeve- taper and sleeve-bore, stem-taper surfaces) than other MoM devices are expected to release greater number of ions. Concerns have been expressed that the ion release at the taper junction might be a potential cause leading to the failure of the implant [Garbuz The aim of this study was to look into the wear and the associated ion release from the taper junction and the articulating surface of modular devices. For the first time a novel design has been used to isolate the taper junction on modular devices on the hip simulators in order to compare the wear at the taper junction and articulating surface. The taper junction has been isolated in a small gaiter, while the head and cup were contained in a large gaiter. CoCrMo sleeves having an offset of +8 mm have been used on 50 mm modular heads along with Ti6Al4V stems. The acetabular components were standard BHR cups. Three devices (Smith & Nephew, UK) have been tested with newborn calf serum as a lubricant (in the large gaiter) and also as the medium containing the taper junction (in the small gaiter). The serum samples from the articulating surface and taper junction were analysed using HR-ICPMS. The locking interfaces at the taper junction have been left intact throughout the duration of the test. Both the head and the cup have been tested under anatomical conditions using the standard implant development centre's (IDC) profile for 2 million cycles (Mc). The lubricant was newborn calf serum with 0.2% sodium azide diluted with de-ionised water to achieve protein concentration of 20 mg/ml. The flexion/extension was 30°/15° and the internal/external rotation was ±10°. The force was Paul-type stance phase loading with a maximum load of 3 kN and a standard ISO swing phase load of 0.3 kN. The frequency was 1 Hz, with an 8 hour stop after every 16 hours of testing.Introduction
Method
INTRODUCTION. The risk of dislocation in large diameter metal on metal hip replacement is significantly lower than in standard THR. This is due to the increased primary arc, increased jump distance and possibly a suction effect. Our unit has performed over 1500 of these cases with an overall revision rate of <1%. We report a case series of dislocations in 5 large diameter metal on metal hips undertaken at our unit. METHOD. All cases were reduced closed and investigated for cause of dislocation. Radiological investigation included plain film radiographs and CT to exclude component mal-position and MRI to document soft tissue deficiency.
Introduction: We hypothesised that a stemmed hybrid total hip replacement with a large
During the past fifty years
Wear measurements of 100 explanted hips have been carried out on a Taylor Hobson 365 Roundness Machine using the LIRC Wear Protocol. It was found that 50% of explanted cups were wearing less than 5 μm/year and 60% of components were wearing less than 10 μm/year. Wear tests on hip joint simulators predict wear rates between 2 and 8 μm/year. However, 6% of cups are wearing faster than 100 μm/year, with 16% of cups have wear patches deeper than 100 μm and that 4% have a wear patch deeper than 300 μm.
Cup position is an important factor, all of the high wearing components are outside the Lewinick’s Box, however it is shown that mal position is does not always lead to extreme wear. Further analysis is taking place to calculate the size of the contact patch between head and cup (based on patient data and biomechanics) and the proximity of the contact patch to the edge of the cup.
This prospective study evaluates the outcome of a new
We report a 10% failure rate for aseptic loosening and overall revision rate of 15% at 5 years mean follow up in 190 patients using the Cormet 2000 Dual coat ace-tabular component. Between April 2001 and March 2004, this cup was used in our region by 4 surgeons. It was peripherally expanded and comprised a cobalt chrome shell, plasma sprayed with a further layer of cobalt chrome which was then coated with hydroxyapatite. This backing has since been abandoned in favour of a titanium plasma coat beneath the hydroxyapatite because of a higher than expected incidence of early loosening. There were 190 cups implanted in 174 patients, 142 with resurfacing heads. The average age was 54 and 99 were male. Revision for aseptic loosening was required in 20 cups (10%) at a mean interval of 23 months including five within 2 months, Of the early revisions three developed a deep infection. Undiagnosed groin pain in four further patients appeared at revision to arise from an inflamed bursa secondary to impingement of psoas tendon on the rim of the cup. There was one primary infection, one infection following revision of a trochanteric osteotomy and two neck fractures. Persistent unexplained groin pain was seen in three patients who have declined further surgery Failure of this backing to integrate with bone led to an unacceptably high early loosening rate. Positioning of the larger resurfacing cups is critical to avoid painful irritation of psoas. Early revision carries a high risk of infection.
In our independent centre, in the period from January 2003 to august 2008, over 1100 36mm MoM THRs have been implanted as well as 155 Birmingham Hip Resurfacing procedures, 402 ASR resurfacings and 75 THRs using ASR XL heads on SROM stems. During this period we have experienced a number of failures with patients complaining of worsening groin pain at varying lengths of time post operatively. Aspiration of the hip joints yielded a large sterile effusion on each occasion. At revision, there were copious amounts of green grey fluid with varying degrees of necrosis. There were 11 failures of this nature in patients with ASR implants (10 females) and 2 in the 36 MoM THR group (one male one female). Tissue specimens from revision surgery showed varying degrees of ‘ALVAL’ as well as consistently high numbers of histiocytes.
We retrospectively reviewed the mid term outcome of 88 MoM THA in 84 patients and 21Hip Resurfacing using Recap Magnum bearing surface performed during 2006 – 2009. There were 41 males and 47 females in the THA group and 17 males and 4 females in the Hip Resurfacing group. All procedures were performed through a posterior approach. The average head size for the THR group was 46mm and the cup size was 52mm and the average head size for the resurfacing was 50mm and cup size was 56mm respectively. Median age for the THA group was 60 yrs. (28–73) and for the Resurfacing it was 51.5 yrs. (32–62). Average follow up was 76 months for the THA group and 78 months for the Resurfacing group. Average serum cobalt for the THA and the Resurfacing groups were 53.2nmol/l (119) and 30.85 and the Chromium levels were 82.44nmol/l(134.5) and 67.49 respectively. Eight MRI scans showed abnormal fluid collections suspicious of ARMD in the THA group and 2 showed fluid collection in the Resurfacing group. There were five revisions in the THA group with the tissue diagnosis of ALVAL. In all except one case a well fixed uncemented stem (Taperloc) was retained. In our series Recap Magnum on a Taperloc stem showed 94% survival at five years and therefore we continue to review the cases annually with serum cobalt chromium levels and MRI scans.
In vitro the introduction of microseparation and edge loading to hip simulator gait cycle has replicated clinically relevant wear rates and wear mechanisms in ceramic-on-ceramic bearings[1], and elevated the wear rates of MoM surface replacements (SR) to levels similar to those observed in retrievals[2]. The aim was to assess the wear of two different sized MoM total hip replacement bearings under steep cup inclination angles and adverse microseparation and edge loading conditions. Two tests were performed on the Leeds II hip joint simulator using two different size bearings (28mm and 36mm). Cups were mounted to provide inclination angles of 45 degrees (n=3) and 65 degrees (n=3). The first three million cycles were under standard gait conditions. Microseparation and edge loading conditions as described by Nevelos et al[1] were introduced to the gait cycle for the subsequent three million cycles. The lubricant was 25% new born calf serum. The mean wear rates and 95% confidence limits were determined and statistical analysis was performed using One Way ANOVA. Under standard gait conditions, when the cup inclination angle increased from 45 degrees to 65 degrees, the wear of size 28mm bearing significantly (p=0.004) increased by 2.7-fold, however, the larger bearings did not show any increase in wear (p=0.9). The introduction of microseparation conditions resulted in a significant (p=0.0001) increase in wear rates for both bearing sizes under both cup inclination angle conditions. Under microseparation conditions, the increase in cup inclination angle had no influence on the wear rate for both bearing sizes (Figure 1). With larger bearings, head-rim contact occurs at a steeper cup inclination angle providing an advantage over smaller bearings. The introduction of edge loading and microseparation conditions resulted in a significant increase in wear rates for both bearing sizes. The wear rates obtained in this study under combined increased cup inclination angle and microseparation were half of those obtained when SR MoM bearings were tested under similar adverse conditions[2]. This study shows the importance of prosthesis design and accurate surgical positioning of the head and acetabular cup in MoM THRs.
Orthopaedic cobalt chromium particles and ions can induce indirect DNA damage and chromosome aberrations in human cells on the other side of a cellular barrier in tissue culture. This occurs by intercellular signalling across the barrier. We now show that the threshold for this effect depends on the
Background. Revision surgery for failed metal-on-metal (MOM) total hip arthroplasty (THA) or hip resurfacing (HR) has been a challenge. Previous studies have reported high failure and complication rates, including dislocation, infection, aseptic loosening and lower patient satisfaction. Options for revision depend on the integrity and stability of the femoral and acetabular components. When both components fail, full revision is required; however, when the acetabular component remains well fixed and oriented, only the isolated femoral component revision can be performed. Dual mobility components can be utilized to match the size to the inner diameter of the
Introduction:. The clinical significance of serum
Development of the
Metal-on-metal bearing surfaces have been reintroduced for use in total hip replacement, despite concerns regarding the potential risks posed by metallic by-products. We have compared periprosthetic tissues from metal-on-metal and metal-on-polyethylene hip replacements at revision surgery with control tissues at primary arthroplasty. Tissues were obtained from 9 control, 25 contemporary metal-on-metal, 9 CoCr-on-polyethylene and 10 titanium-on-polyethylene hip replacement arthroplasties. Each was processed for routine histology with Haematoxylin and Eosin. Quantitative stereological analysis was performed at the light microscopic level. Metal-on-metal sections showed more surface ulceration and this was correlated with the density of inflammation in the deeper tissues layers. Metal-on-metal tissues displayed a pattern of well-demarcated tissue layers, which were rarely seen in metal-on-polyethylene cases. In metal-on-polyethylene cases, the inflammation was predominantly histiocytic. Metal-on-metal cases by contrast showed a lymphocytic infiltrate with abundant plasma cells. Metal-on-metal tissues showed a striking pattern of peri-vascular inflammation with prominent lymphocytic cuffs especially deep to areas of surface ulceration. Levels of inflammation were higher in cases revised for failure than in those retrieved at autopsy or exploratory surgery. Total replacement and surface replacement designs of metal-on-metal arthroplasty showed similar histological changes. Plasma cells were not seen in any of the metal-on-polyethylene cases. The differences between the patterns of inflammation and cellular infiltration seen in metal-on-metal and metal-on-polyethylene tissues were highly statistically significant. The pattern and type of inflammation in periprosthetic tissues from metal-on-metal and metal-on-poly-ethylene arthroplasties is very different. Our findings support the conclusion that metal-on-metal articulations are capable of generating a form of immunological response to metallic wear debris that has not been described previously. The incidence and clinical implications of these immunological responses in failed metal-on-metal joints are unknown.
To review short to medium term results of a metalon-metal (M/M) hybrid surface arthroplasty (SA) for a young and active patient population. The first 300 hips (of 564) in 263 patients underwent M/M hybrid surface arthroplasty (cementless acetabular and cemented femoral components). Demographics: mean age 48.4; 75% males, 25% females; 141 Charnley Class A; 109 Class B and 13 Class C. Diagnosis at surgery: OA 67%, DDH 10.3%, ON 8.3%, Post-traumatic 6.7%, Inflammatory arthritis and Rheumatoid Disease 4%, SCFE and LCP 3.4%, Melorheostosis 0.3%. Mean follow-up 3.6 years (2.5–5.9). Average UCLA hip scores post-op: pain 9.4, walking 9.5, function 9.4 and activity 7.7. Average Harris Hip Score was 92.8. The SF-12 physical and mental components were respectively, 31.4 and 47.2 pre-op and 49.9 and 52.9 post-op. DEXA data suggests preservation or restoration of neck BMD. The experience with SA of all cemented
Aims. The Birmingham Hip Resurfacing (BHR) arthroplasty has been used as a surgical treatment of coxarthrosis since 1997. We present 20-year results of 234 consecutive BHRs performed in our unit. Methods. Between 1999 and 2001, there were 217 patients: 142 males (65.4%), mean age 52 years (18 to 68) who had 234 implants (17 bilateral). They had patient-reported outcome measures collected, imaging (radiograph and ultrasound), and serum
Our experience with
Aims: Review short to medium term results of a metal-on-metal (M/M) hybrid surface arthroplasty (SA) for a young and active patient population. Methods: The þrst 400 hips (of 533) in 355 patients underwent M/M hybrid surface arthroplasty. Mean age 48.2; 73% males, 27% females; 198 Charnley Class A; 139 Class B and 18 Class C. Diagnosis at surgery: OA 64%, DDH 11%, ON 9%, Post-traumatic 8%, Inßammatory arthritis 3%, SCFE and LCP 4%, Melorheostosis 0.3%. Results: Mean follow-up 3.9 years (2.6–6.5). Average UCLA hip scores post-op: pain 9.4, walking 9.5, function 9.4, and activity 7.7. The SF-12 physical and mental components were respectively, 31.2 and 46.8 pre-op and 50.1 and 53.0 post-op. 12 hips were converted to THA (8 in the þrst 102): 2 neck fractures, 7 femoral loosenings, 1 socket protrusio due to over-reaming, 1 subluxation due to impingement and 1 sepsis. Conclusions: Clinical results are excellent despite very high activity levels. The experience with SA of all cemented
The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive any payments or make agreements to provide such benefit from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other non profit organization with which the authors are affiliated or associated. Background: We observed early osteolysis and loosening of the rough surface-cement stem with a second generation metal-on-metal articulation. This study was to investigate the possible etiologic role of stem loosening and osteolysis by examination of the surface of the rough blast cement and related periprosthetic tissues that have been retrieved at revision. Methods: We retrospectively analyzed 39 hips (37 patients) with use of metasul metal-on-metal total hip arthroplasty. Of the femoral stem, rough surface-cement stem used in 18 hips and cementless Ti-alloy stem in 21 hips. The mean duration of follow-up was 10.2 years. Of these eight rough blast cement stem were revised, seven in loosening and one in recurrent dislocation. By using energy disperse spectroscope and back scattered electron image, histologic studies were performed to the samples of periprosthetic tissues. Skin patch tests for
Introduction. It is well-known that wear debris generated by metal-on-metal hip replacements leads to aseptic loosening. This process starts in the local tissue where an inflammatory reaction is induced, followed by an periprosthetic osteolysis. MOM bearings generate particles as well as ions. The influence of both in human bodies is still the subject of debate. For instance hypersensitivity and high blood
Aims. The purpose of this study was to compare two different types
of metal-on-metal (MoM) bearing for total hip arthroplasty (THA):
one with a large femoral head (38 mm to 52 mm) and the other with
a conventional femoral head (28 mm or 32 mm). We compared clinical
outcome, blood
In this prospective study a total of 80 consecutive
Chinese patients with Crowe type I or II developmental dysplasia of
the hip were randomly assigned for hip resurfacing arthroplasty
(HRA) or total hip replacement (THR). Three patients assigned to HRA were converted to THR, and three
HRA patients and two THR patients were lost to follow-up. This left
a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips)
who underwent THR. The mean follow-up was 59.4 months (52 to 70)
in the HRA group and 60.6 months (50 to 72) in the THR group. There was
no failure of the prosthesis in either group. Flexion of the hip
was significantly better after HRA, but there was no difference
in the mean post-operative Harris hip scores between the groups.
The mean size of the acetabular component in the HRA group was significantly
larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was
no difference in the mean abduction angle of the acetabular component
between the two groups. Although the patients in this series had risk factors for failure
after HRA, such as low body weight, small femoral heads and dysplasia,
the clinical results of resurfacing in those with Crowe type I or
II hip dysplasia were satisfactory. Patients in the HRA group had
a better range of movement, although neck-cup impingement was observed.
However, more acetabular bone was sacrificed in HRA patients, and
it is unclear whether this will have an adverse effect in the long
term.
Cemented total hip arthroplasty yields reliable results in short to medium term studies, but aseptic loosening remains a problem in long-term follow up, especially in young and active patients. Aseptic loosening has been related to wear, and in order to minimize wear various alternatives to the traditional
Introduction. Clinically relevant attributes of an orthopedic bearing material include its strength, oxidative stability, and wear resistance. Recent reductions in bearing wear and oxidation have been realized by crosslinking (HXLPE), and through the incorporation of α-tocopherol (VE). VE infusion has improved the oxidative stability of HXLPE in vitro [1] and in vivo (as evidenced by retrievals) [2]. However, concern has been raised that adding VE may increase the frictional torque of bearings, potentially increasing the risk of trunnionosis [3]. This study compares the 3D frictional torques of HXLPE vs Vitamin-E HXPLE, against 28 mm and 36 mm
The implantation of endoprosthesis is a routine procedure in orthopaedics. Endoprosthesis are mainly manufactured from ceramics, polymers,
An increase in
Aim. Antibacterial activity of coatings based on
Cobalt chrome alloy is commonly used in joint replacement surgery. However, it is recognised that some patients develop lymphocyte mediated delayed type hypersensitivity (DTH) responses to this material, which may result in extensive bone and soft tissue destruction. Phase 1. United Kingdom: From an existing database, we identified extreme phenotype patient groups following
The biological reaction in metallosis and pseudotumor generation after
Summary. Management of metal on metal hip replacements can be accomplished with a simple algorithm including easily available
We performed a prospective, randomised, blinded clinical trial comparing
Orthopaedic implants, such as femoral heads, sockets and stems, are manufactured with a high degree of smoothness and very low form error in order to function as low wear bearings. The surfaces are subject to both wear and damage during in vivo use. Articulating surfaces naturally wear during normal use. Aseptic loosening associated with osteolysis and release of wear particles is the main reason for revision of total hip arthroplasty (THA). Damage of femoral heads is well known to increase the wear rate at the articulating surface and is vulnerable to scratching during the maneuver of positioning the femoral component into the acetabulum component either in primary as in revision total hip arthroplasties. The findings emphasize the importance of achieving and maintaining good surface finish of the femoral head component. The author presents a very simple and “zero cost” method of preventing scratching of the femoral head of any kind of total hip prosthesis (ceramic on ceramic, ceramic on poly,
It is accepted that larger diameter heads are more difficult to dislocate due to the increased distance the head has to travel to come out of the cup. Currently larger femoral heads are being used for their resistance to dislocation however, there remains little reporting on the effect of design of cup on jump distance. Monoblock
Introduction. Bearing surfaces used for total hip arthroplasty must have characteristics including bio-compatibility, low friction and low wear rate. Bearing combinations are generally characterised as Soft on Hard/Hard. In general, all newer bearing combinations have reduced wear but may present with other issues that impact on patient outcomes. Materials. The Australian Orthopaedic Association – National Joint Replacement Registry classifies bearing surfaces into six categories. These are
Introduction: Although good mid-term results have been reported with some metal on metal hip replacements, reported complications due to
Introduction. The rise of the anterior approach (AA) in primary surgery has led to enthusiasm for using this approach in revision surgery, especially because head and liner exchanges have been accompanied by a high dislocation rate when the posterior approach (PA) is used. The aim of this study was to compare the institutional dislocation rate comparing the PA and AA in isolated head and liner exchange. Methods. A retrospective institutional database query was done to identify all aseptic head and liner exchanges between the years 2010- June, 2020. 186 hips were identified with an average age of 64.8+/−10.8 yrs (27.9–87.6) and average BMI of 28.7+/−6.3 kg/m2 (16.2–52). The reason for revision was polyethylene wear and osteolysis in 105 hips (56.5%), adverse tissue reaction to
Young and active patients require bearing materials that can last up to 200 million walking steps, ten fold greater than conventional polyethylene bearings. Cross linked polyethylene provides reduced wear rate compared to conventional polyethylene, and further advantage is gained from using ceramic femoral heads. However in polyethylene bearings wear increases with the head diameter, and there is currently little opportunity to use head sizes greater then 36mm diameter. There is evidence of polyethylene fracture with steeply positioned cups. Ceramic on ceramic bearings provide substantially lower wear rates than polyethylene bearings. Steep cups, lateralised heads or neck impingement can lead to head contact on superior rim of the cup and stripe wear, but this still results in very low wear rates. Recently developed ceramic matrix composites Biolox Delta provide greater resistance to stripe wear. In a few patients stripe wear may lead to squeaking.
The purpose of this study is to evaluate short to mid-term clinical and radiological results of
The main problem of modern total hip replacement is the reduction of wear debris. Hence, new tribological partners such as ceramic on ceramic,
INTRODUCTION. The advantages of large diameter
Aims: A polyethylene free,
Objectives. Total hip replacement is increasingly being conducted in younger and more active patients, so surgeons often use bearing surfaces with improved wear characteristics, such as ceramic on ceramic. The primary objective of this study was to determine if survivorship for a BIOLOX® delta ceramic on delta ceramic couple used with the PROCOTYL® L acetabular cup is significantly different from all other cementless cups in a large arthroplasty registry. The secondary objective of this study was to analyze patient reported outcomes measures (PROMs) of the subject cup with a minimum five year follow-up. Methods. Patient demographics and survivorship data was collected from the National Joint Registry of England, Wales, Northern Ireland, and the Isle of Man (NJR) database for all total hip replacements performed with the PROCOTYL® L cup used in combination with a delta-on-delta articulation, as well as for all other cementless cups. Survivorship data was compared for all revisions and cup revisions only and data was adjusted to exclude
Introduction. Mix and Match (M&M) describes the use of components from more than one manufacturer in a total hip replacement (THR) The NJR has records of over 90,000 instances where this practice, which is contrary to the advice of most manufacturers and regulators, has been followed. Patients, Materials and Method. The NJR database 2003–13 was interrogated and the types of M&M were grouped using head size, bearing characteristics and use of cement. Results. Total Cohort. M&M. HARD ON SOFT.
Introduction: Historically Surface Replacement of the Hip exhibited a high failure rate due to femoral head loosening attributed to polyethylene wear debri, originating from the acetabulum. A
Introduction. Fretting corrosion at the Head-Neck taper interface of Large