Aims. Several short- and mid-term studies have shown minimal liner
Aims. The aims of this study were to evaluate
Aims. The primary objective of this study was to compare the five-year tibial component migration and
Aims. A retrospective longitudinal study was conducted to compare directly volumetric
Aims. A retrospective study was conducted to measure short-term in vivo linear and volumetric
Aims. We aimed to investigate if the use of the largest possible cobalt-chromium head articulating with polyethylene acetabular inserts would increase the in vivo
We analysed 54 alumina ceramic-on-ceramic bearings
from total hip replacements retrieved at one centre after a mean
duration of 3.5 years (0.2 to 10.6) in situ. These
implants were obtained from 54 patients (16 men and 38 women) with
a mean age of 67 years (33 to 88) who underwent revision for a variety
of reasons. Posterior edge loading was found in the majority of
these retrievals (32 out of 54). Anterosuperior edge loading occurred
less often but produced a higher rate of
Aims. The increased in vivo resistance to
Aims. A significant reduction in
Aims.
Aims. Oxidized zirconium (OxZi) and highly cross-linked polyethylene (HXLPE) were developed to minimize
Aims. This study aimed to assess the impact of using the metal-augmented glenoid baseplate (AGB) on improving clinical and radiological outcomes, as well as reducing complications, in patients with superior glenoid
Aims. The aim of this study was to evaluate the performance of first-generation annealed highly cross-linked polyethylene (HXLPE) in cementless total hip arthroplasty (THA). Methods. We retrospectively evaluated 29 patients (35 hips) who underwent THA between December 2000 and February 2002. The survival rate was estimated using the Kaplan-Meier method. Hip joint function was evaluated using the Japanese Orthopaedic Association (JOA) score. Two-dimensional polyethylene
Aims. Vitamin E-infused highly cross-linked polyethylene (E1) has recently been introduced in total knee arthroplasty (TKA). An in vitro
Aims. Isolated acetabular liner exchange with a highly crosslinked polyethylene (HXLPE) component is an option to address polyethylene
Aims. A contact patch to rim (CPR) distance of <
10 mm has been
associated with edge-loading and excessive
Aims. The aim of this study was to determine whether there is a difference
in the rate of
Aims. The primary aim of this study was to compare the
The Oxford Unicompartmental Knee replacement (UKR) was introduced as a design to reduce polyethylene
This multicentre study analysed 12 alumina ceramic-on-ceramic
components retrieved from squeaking total hip replacements after
a mean of 23 months in situ (11 to 61). The rates
and patterns of
There are many methods for analysing
Aims. The purpose of this study was to compare the long-term results
of primary total hip arthroplasty (THA) in young patients using
either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene
liner in terms of functional outcome, incidence of osteolysis, radiological
wear and rate of revision. Methods. We included all patients between the ages of 45 and 65 years
who, between January 2000 and December 2001, had undergone a primary
THA for osteoarthritis at our hospital using a CPE or HXLPE acetabular
liner and a 28 mm cobalt-chrome femoral head. . From a total of 160 patients, 158 (177 hips) were available for
review (CPE 89; XLPE 88). The mean age, body mass index (BMI) and
follow-up in each group were: CPE: 56.8 years (46 to 65); 30.7 kg/m. 2. (19
to 58); 13.2 years (2.1 to 14.7) and HXLPE: 55.6 years (45 to 65);
BMI: 30 kg/m. 2. (18 to 51); 13.1 years (5.7 to 14.4). Results. The mean Harris hip score (HHS) at final follow-up was 89.3 for
the CPE group and 90.9 for the HXLPE group (p = 0.078). Osteolysis
was present around 15 acetabular (17%) and 16 femoral (18%) components
in the CPE hips compared with none (0%) in the HXLPE hips. The mean
radiological linear
Since the Oxford knee was first used unicompartmentally
in 1982, a small number of bearings have fractured. Of 14 retrieved
bearings, we examined ten samples with known durations in
situ (four Phase 1, four Phase 2 and two Phase 3). Evidence
of impingement and associated abnormally high
The Oxford unicompartmental knee replacement (UKR) was designed to minimise
The creep and
Aims. Vitamin E-diffused, highly crosslinked polyethylene (VEPE) and porous titanium-coated (PTC) shells were introduced in total hip arthroplasty (THA) to reduce the risk of aseptic loosening. The purpose of this study was: 1) to compare the
We investigated the rate of polyethylene
We report the five-year outcome of a randomised
controlled trial which used radiostereometric analysis (RSA) to assess
the influence of surface oxidised zirconium (OxZr, Oxinium) on polyethylene
wear in vivo. A total of 120 patients, 85 women and 35 men with a mean age
of 70 years (59 to 80) who were scheduled for primary cemented total
hip arthroplasty were randomly allocated to four study groups. Patients
were blinded to their group assignment and received either a conventional
polyethylene (CPE) or a highly cross-linked (HXL) acetabular component
of identical design. On the femoral side patients received a 28
mm head made of either cobalt-chromium (CoCr) or OxZr. . The proximal head penetration (wear) was measured with repeated
RSA examinations over five years. Clinical outcome was measured
using the Harris hip score. . There was no difference in polyethylene
The presence of pseudotumours, which are soft-tissue masses relating to the hip, after metal-on-metal hip resurfacing arthroplasty has been associated with elevated levels of metal ions in serum, suggesting that pseudotumours occur when there is increased
Complications involving the patellofemoral joint,
caused by malrotation of the femoral component during total knee replacement,
are an important cause of persistent pain and failure leading to
revision surgery. The aim of this study was to determine and quantify
the influence of femoral component malrotation on patellofemoral
wear, and to determine whether or not there is a difference in the
rate of
Oxidised zirconium (OxZi) has been developed
as an alternative bearing surface for femoral heads in total hip arthroplasty
(THA). This study has investigated polyethylene
We measured the orientation of the acetabular and femoral components in 45 patients (33 men, 12 women) with a mean age of 53.4 years (30 to 74) who had undergone revision of metal-on-metal hip resurfacings. Three-dimensional CT was used to measure the inclination and version of the acetabular component, femoral version and the horizontal femoral offset, and the linear
Polyethylene particulate
Aims. This paper describes the methodology, validation and reliability
of a new computer-assisted method which uses models of the patient’s
bones and the components to measure their migration and polyethylene
wear from radiographs after total hip arthroplasty (THA). Materials and Methods. Models of the patient’s acetabular and femoral component obtained
from the manufacturer and models of the patient’s pelvis and femur
built from a single computed tomography (CT) scan, are used by a
computer program to measure the migration of the components and
the penetration of the femoral head from anteroposterior and lateral radiographs
taken at follow-up visits. The program simulates the radiographic
setup and matches the position and orientation of the models to
outlines of the pelvis, the acetabular and femoral component, and
femur on radiographs. Changes in position and orientation reflect
the migration of the components and the penetration of the femoral
head. Validation was performed using radiographs of phantoms simulating
known migration and penetration, and the clinical feasibility of
measuring migration was assessed in two patients. Results. Migration of the acetabular and femoral components can be measured
with limits of agreement (LOA) of 0.37 mm and 0.33 mm, respectively.
Penetration of the femoral head can be measured with LOA of 0.161
mm. Conclusion. The migration of components and polyethylene
We studied 33 third generation, alumina ceramic-on-ceramic bearings retrieved from cementless total hip replacements after more than six months in situ.
The biological significance of cobalt-chromium
We made a clinical study of polyethylene
The issues surrounding raised levels of metal
ions in the blood following large head metal-on-metal total hip replacement
(THR), such as cobalt and chromium, have been well documented. Despite
the national popularity of uncemented metal-on-polyethylene (MoP)
THR using a large-diameter femoral head, few papers have reported
the levels of metal ions in the blood following this combination.
Following an isolated failure of a 44 mm Trident–Accolade uncemented
THR associated with severe
Polyethylene
Polyethylene acetabular cups retrieved at revision surgery were measured by a shadowgraph technique to determine linear
We analysed in-vivo migration and
The inherent challenges of total hip replacement
(THR) in children include the choice of implant for the often atypical
anatomical morphology, its fixation to an immature growing skeleton
and the bearing surface employed to achieve a successful long-term
result. We report the medium-term results of 52 consecutive uncemented
THRs undertaken in
35 paediatric patients with juvenile idiopathic arthritis. The mean
age at the time of surgery was 14.4 years (10 to 16). The median
follow-up was 10.5 years (6 to 15). During the study period 13 THRs
underwent revision surgery. With revision as an endpoint, subgroup
analysis revealed 100% survival of the 23 ceramic-on-ceramic THRs
and 55% (16 of 29) of the metal- or ceramic-on-polyethylene. This
resulted in 94% (95% CI 77.8 to 98.4) survivorship of the femoral
component and 62% (95% CI 41.0 to 78.0) of the acetabular component.
Revision of the acetabular component for
Isolated
Many designs of unicompartmental knee replacement show early and mid-term failure due to polyethylene
We examined radiographic polyethylene
We measured polyethylene
Since
The ABG I cementless hip prosthesis has demonstrated unacceptably high rates of
We used radiostereometric analysis to compare