In Asia and the Middle-East, people often flex their knees deeply
in order to perform activities of daily living. The purpose of this
study was to investigate the 3D kinematics of normal knees during
high-flexion activities. Our hypothesis was that the femorotibial
rotation, varus-valgus angle, translations, and kinematic pathway
of normal knees during high-flexion activities, varied according
to activity. We investigated the Aims
Materials and Methods
This 501-patient, multi-centre, randomised controlled trial sought
to establish the effect of low-intensity, pulsed, ultrasound (LIPUS)
on tibial shaft fractures managed with intramedullary nailing. We
conducted an economic evaluation as part of this trial. Data for patients’ use of post-operative healthcare resources
and time taken to return to work were collected and costed using
publicly available sources. Health-related quality of life, assessed
using the Health Utilities Index Mark-3 (HUI-3), was used to derive
quality-adjusted life years (QALYs). Costs and QALYs were compared
between LIPUS and control (a placebo device) from a payer and societal
perspective using non-parametric bootstrapping. All costs are reported
in 2015 Canadian dollars unless otherwise stated.Aims
Patients and Methods
Up to 40% of unicompartmental knee arthroplasty (UKA) revisions are performed for unexplained pain which may be caused by elevated proximal tibial bone strain. This study investigates the effect of tibial component metal backing and polyethylene thickness on bone strain in a cemented fixed-bearing medial UKA using a finite element model (FEM) validated experimentally by digital image correlation (DIC) and acoustic emission (AE). A total of ten composite tibias implanted with all-polyethylene (AP) and metal-backed (MB) tibial components were loaded to 2500 N. Cortical strain was measured using DIC and cancellous microdamage using AE. FEMs were created and validated and polyethylene thickness varied from 6 mm to 10 mm. The volume of cancellous bone exposed to < -3000 µε (pathological loading) and < -7000 µε (yield point) minimum principal (compressive) microstrain and > 3000 µε and > 7000 µε maximum principal (tensile) microstrain was computed.Objectives
Materials and Methods
The primary aim of this independent prospective randomised trial
was to compare serum metal ion levels for ceramic-on-metal (CoM)
and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty
(THA). Our one-year results demonstrated elevation in metal ion
levels above baseline with no significant difference between the
CoM and MoM groups. This paper reviews the five-year data. The implants used in each patient differed only in respect to
the type of femoral head (ceramic or metal). At five-year follow-up
of the 83 enrolled patients, data from 67 (36 CoM, 31 MoM) was available
for comparison.Aims
Patients and Methods
The aims of this study were to determine the proportion of patients
with outlier varus or valgus alignment in kinematically aligned
total knee arthroplasty (TKA), whether those with outlier varus
or valgus alignment have higher forces in the medial or lateral
compartments of the knee than those with in-range alignment and
whether measurements of the alignment of the limb, knee and components
predict compartment forces. The intra-operative forces in the medial and lateral compartments
were measured with an instrumented tibial insert in 67 patients
who underwent a kinematically aligned TKA during passive movement.
The mean of the forces at full extension, 45° and 90° of flexion
determined the force in the medial and lateral compartments. Measurements
of the alignment of the limb and the components included the hip-knee-ankle
(HKA) angle, proximal medial tibial angle (PMTA), and distal lateral
femoral angle (DLFA). Measurements of the alignment of the knee
and the components included the tibiofemoral angle (TFA), tibial
component angle (TCA) and femoral component angle (FCA). Alignment was
measured on post-operative, non-weight-bearing anteroposterior (AP)
scanograms and categorised as varus or valgus outlier or in-range
in relation to mechanically aligned criteria.Aims
Patients and Methods
There is little evidence on the cost effectiveness
of different brands of hip prostheses. We compared lifetime cost effectiveness
of frequently used brands within types of prosthesis including cemented
(Exeter V40 Contemporary, Exeter V40 Duration and Exeter V40 Elite
Plus Ogee), cementless (Corail Pinnacle, Accolade Trident, and Taperloc Exceed)
and hybrid (Exeter V40 Trilogy, Exeter V40 Trident, and CPT Trilogy).
We used data from three linked English national databases to estimate
the lifetime risk of revision, quality-adjusted life years (QALYs)
and cost. For women with osteoarthritis aged 70 years, the Exeter V40 Elite
Plus Ogee had the lowest risk of revision (5.9% revision risk, 9.0
QALYs) and the CPT Trilogy had the highest QALYs (10.9% revision
risk, 9.3 QALYs). Compared with the Corail Pinnacle (9.3% revision
risk, 9.22 QALYs), the most commonly used brand, and assuming a
willingness-to-pay of £20 000 per QALY gain, the CPT Trilogy is
most cost effective, with an incremental net monetary benefit of £876.
Differences in cost effectiveness between the hybrid CPT Trilogy
and Exeter V40 Trident and the cementless Corail Pinnacle and Taperloc
Exceed were small, and a cautious interpretation is required, given
the limitations of the available information. However, it is unlikely that cemented brands are among the most
cost effective. Similar patterns of results were observed for men
and other ages. The gain in quality of life after total hip arthroplasty,
rather than the risk of revision, was the main driver of cost effectiveness. Cite this article:
We sought to establish whether an oxidised zirconium (OxZr) femoral
component causes less loss of polyethylene volume than a cobalt
alloy (CoCr) femoral component in total knee arthroplasty. A total of 20 retrieved tibial inserts that had articulated with
OxZr components were matched with 20 inserts from CoCr articulations
for patient age, body mass index, length of implantation, and revision
diagnosis. Changes in dimensions of the articular surfaces were compared
with those of pristine inserts using laser scanning. The differences
in volume between the retrieved and pristine surfaces of the two
groups were calculated and compared.Aims
Materials and Methods
Intramedullary fixation is considered the most stable treatment for pertrochanteric fractures of the proximal femur and cut-out is one of the most frequent mechanical complications. In order to determine the role of clinical variables and radiological parameters in predicting the risk of this complication, we analysed the data pertaining to a group of patients recruited over the course of six years. A total of 571 patients were included in this study, which analysed the incidence of cut-out in relation to several clinical variables: age; gender; the AO Foundation and Orthopaedic Trauma Association classification system (AO/OTA); type of nail; cervical-diaphyseal angle; surgical wait times; anti-osteoporotic medication; complete post-operative weight bearing; and radiological parameters (namely the lag-screw position with respect to the femoral head, the Cleveland system, the tip-apex distance (TAD), and the calcar-referenced tip-apex distance (CalTAD)).Objectives
Methods
The morphometry of the distal femur was largely studied to improve
bone-implant fit in total knee arthroplasty (TKA), but little is
known about the asymmetry of the posterior condyles. This study
aimed to investigate the dimensions of the posterior condyles and
the influence of externally rotating the femoral component on potential prosthetic
overhang or under-coverage. We analysed the shape of 110 arthritic knees at the time of primary
TKA using pre-operative CT scans. The height and width of each condyle
were measured at the posterior femoral cut in neutral position,
and in 3º and 5º of external rotation, using both central and medial
referencing systems. We compared the morphological characteristics
with those of 14 TKA models.Aims
Patients and Methods
Despite being one of the most common orthopaedic
operations, it is still not known how many arthroscopies of the knee
must be performed during training in order to develop the skills
required to become a Consultant. A total of 54 subjects were divided
into five groups according to clinical experience: Novices (n =
10), Junior trainees (n = 10), Registrars (n = 18), Fellows (n =
10) and Consultants (n = 6). After viewing an instructional presentation,
each subject performed a simple diagnostic arthroscopy of the knee
on a simulator with visualisation and probing of ten anatomical
landmarks. Performance was assessed using a validated global rating
scale (GRS). Comparisons were made against clinical experience measured
by the number of arthroscopies which had been undertaken, and ROC
curve analysis was used to determine the number of procedures needed
to perform at the level of the Consultants. There were marked differences between the groups. There was significant
improvement in performance with increasing experience (p <
0.05). ROC curve analysis identified that approximately 170 procedures
were required to achieve the level of skills of a Consultant. We suggest that this approach to identify what represents the
level of surgical skills of a Consultant should be used more widely
so that standards of training are maintained through the development
of an evidenced-based curriculum. Cite this article:
To assess the effect of high tibial and distal femoral osteotomies
(HTO and DFO) on the pressure characteristics of the ankle joint. Varus and valgus malalignment of the knee was simulated in human
cadaver full-length legs. Testing included four measurements: baseline
malalignment, 5° and 10° re-aligning osteotomy, and control baseline
malalignment. For HTO, testing was rerun with the subtalar joint
fixed. In order to represent half body weight, a 300 N force was applied
onto the femoral head. Intra-articular sensors captured ankle pressure.Aims
Materials and Methods
The aim of this study was to analyse human muscle tissue before
and after rotator cuff repair to look for evidence of regeneration,
and to characterise the changes seen in the type of muscle fibre. Patients were assessed pre-operatively and one year post-operatively
using the Oxford Shoulder Score (OSS) and MRI. The cross-sectional
area and distribution of the type of muscle fibre were assessed
on biopsies, which were taken at surgery and one year post-operatively.
Paired samples from eight patients were analysed. There were three
men and five women with a mean age of 63 years (50 to 73).Aims
Patients and Methods
The bony shoulder stability ratio (BSSR) allows for quantification of the bony stabilisers Four polyethylene balls (radii: 19.1 mm to 38.1 mm) were used to mould four fitting sockets in four different depths (3.2 mm to 19.1mm). The SR was measured in biomechanical congruent and incongruent experimental series. The experimental SR of a congruent system was compared with the calculated SR based on the BSSR approach. Differences in SR between congruent and incongruent experimental conditions were quantified. Finally, the experimental SR was compared with either calculated SR based on the socket concavity or plastic ball radius.Objectives
Methods
Valid and reliable techniques for assessing performance
are essential to surgical education, especially with the emergence
of competency-based frameworks. Despite this, there is a paucity
of adequate tools for the evaluation of skills required during joint
replacement surgery. In this scoping review, we examine current
methods for assessing surgeons’ competency in joint replacement
procedures in both simulated and clinical environments. The ability
of many of the tools currently in use to make valid, reliable and
comprehensive assessments of performance is unclear. Furthermore,
many simulation-based assessments have been criticised for a lack
of transferability to the clinical setting. It is imperative that
more effective methods of assessment are developed and implemented
in order to improve our ability to evaluate the performance of skills
relating to total joint replacement. This will enable educators
to provide formative feedback to learners throughout the training
process to ensure that they have attained core competencies upon
completion of their training. This should help ensure positive patient
outcomes as the surgical trainees enter independent practice. Cite this article:
Previously, we showed that case-specific non-linear
finite element (FE) models are better at predicting the load to failure
of metastatic femora than experienced clinicians. In this study
we improved our FE modelling and increased the number of femora
and characteristics of the lesions. We retested the robustness of
the FE predictions and assessed why clinicians have difficulty in
estimating the load to failure of metastatic femora. A total of
20 femora with and without artificial metastases were mechanically
loaded until failure. These experiments were simulated using case-specific
FE models. Six clinicians ranked the femora on load to failure and
reported their ranking strategies. The experimental load to failure
for intact and metastatic femora was well predicted by the FE models (R2 =
0.90 and R2 = 0.93, respectively). Ranking metastatic
femora on load to failure was well performed by the FE models (τ =
0.87), but not by the clinicians (0.11 <
τ <
0.42). Both the
FE models and the clinicians allowed for the characteristics of
the lesions, but only the FE models incorporated the initial bone
strength, which is essential for accurately predicting the risk
of fracture. Accurate prediction of the risk of fracture should
be made possible for clinicians by further developing FE models.
In May 2012, in airports across the globe, seven
orthopaedic surgeons bravely said goodbye to their loved ones, and
slowly turned towards their respective aircraft. Filled with expectation
and mild trepidation they stepped into the unknown… the ABC fellowship
of 2012.
