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: