Computer hexapod assisted orthopaedic surgery (CHAOS), is a method
to achieve the intra-operative correction of long bone deformities
using a hexapod external fixator before definitive internal fixation
with minimally invasive stabilisation techniques. The aims of this study were to determine the reliability of this
method in a consecutive case series of patients undergoing femoral
deformity correction, with a minimum six-month follow-up, to assess
the complications and to define the ideal group of patients for
whom this treatment is appropriate. The medical records and radiographs of all patients who underwent
CHAOS for femoral deformity at our institution between 2005 and
2011 were retrospectively reviewed. Records were available for all
55 consecutive procedures undertaken in 49 patients with a mean
age of 35.6 years (10.9 to 75.3) at the time of surgery.Aims
Patients and Methods
Determining and accurately restoring the flexion-extension
axis of the elbow is essential for functional recovery after total
elbow arthroplasty (TEA). We evaluated the effect of morphological
features of the elbow on variations of alignment of the components
at TEA. Morphological and positioning variables were compared by
systematic CT scans of 22 elbows in 21 patients after TEA. There were five men and 16 women, and the mean age was 63 years
(38 to 80). The mean follow-up was 22 months (11 to 44). The anterior offset and version of the humeral components were
significantly affected by the anterior angulation of the humerus
(p = 0.052 and p = 0.004, respectively). The anterior offset and
version of the ulnar components were strongly significantly affected
by the anterior angulation of the ulna (p <
0.001 and p <
0.001). The closer the anterior angulation of the ulna was to the joint,
the lower the ulnar anterior offset (p = 0.030) and version of the
ulnar component (p = 0.010). The distance from the joint to the
varus angulation also affected the lateral offset of the ulnar component
(p = 0.046). Anatomical variations at the distal humerus and proximal ulna
affect the alignment of the components at TEA. This is explained
by abutment of the stems of the components and is particularly severe
when there are substantial deformities or the deformities are close
to the joint. Cite this article:
We compared the clinical and radiological outcomes of using a
polyetheretherketone cage with (TiPEEK) and without a titanium coating
(PEEK) for instrumented transforaminal lumbar interbody fusion (TLIF). We conducted a randomised clinical pilot trial of 40 patients
who were scheduled to undergo a TLIF procedure at one or two levels
between L2 and L5. The Oswestry disability index (ODI), EuroQoL-5D,
and back and leg pain were determined pre-operatively, and at three,
six, and 12 months post-operatively. Fusion rates were assessed
by thin slice CT at three months and by functional radiography at
12 months.Aims
Materials and Methods
To clarify the asymmetrical ossification of the epiphyseal ring
between the convex and concave sides in patients with adolescent
idiopathic scoliosis (AIS). A total of 29 female patients (mean age, 14.4 years; 11 to 18)
who underwent corrective surgery for AIS (Lenke type 1 or 2) were
included in our study. In all, 349 vertebrae including 68 apical
vertebrae and 87 end vertebrae in the main thoracic (MT) curve and
thoracolumbar/lumbar (TL/L) curve were analysed. Coronal sections
(anterior, middle and posterior) of the vertebral bodies were reconstructed
from pre-operative CT scans (320-row detector; slice thickness,
0.5 mm) and the appearances of the ossification centre in the epiphyseal
ring at four corners were evaluated in three groups; all vertebrae
excluding end vertebrae, apical vertebrae and end vertebrae. The appearance
rates of the ossification centre at the concave and convex sides
were calculated and compared.Aims
Patients and Methods
The purpose of this study was to clarify the appearance of the reparative tissue on the articular surface and to analyse the properties of the reparative tissue after hemicallotasis osteotomy (HCO) using MRI T1ρ and T2 mapping. Coronal T1ρ and T2 mapping and three-dimensional gradient-echo images were obtained from 20 subjects with medial knee osteoarthritis. We set the regions of interest (ROIs) on the full-thickness cartilage of the medial femoral condyle (MFC) and medial tibial plateau (MTP) of the knee and measured the cartilage thickness (mm) and T1ρ and T2 relaxation times (ms). Statistical analysis of time-dependent changes in the cartilage thickness and the T1ρ and T2 relaxation times was performed using one-way analysis of variance, and Scheffe’s test was employed for Objectives
Methods
The purpose of this study was to develop an accurate, reliable and easily applicable method for determining the anatomical location of the joint line during revision knee arthroplasty. The transepicondylar width (TEW), the perpendicular distance between the medial and lateral epicondyles and the distal articular surfaces (DMAD, DLAD) and the distance between the medial and lateral epicondyles and the posterior articular surfaces (PMAD, DLAD) were measured in 40 knees from 20 formalin-fixed adult cadavers (11 male and nine female; mean age at death 56.9 years, Objectives
Methods
The aim of this study was to assess the reproducibility and validity
of cross table radiographs for measuring the anteversion of the
acetabular component after total hip arthroplasty (THA) and to compare
it with measurements using CT scans. A total of 29 patients who underwent THA between June 2010 and
January 2016 were included. There were 17 men and 12 women. Their
mean age was 43 years (26 to 65). Seven patients underwent a bilateral
procedure. Thus, 36 THAs were included in the study. Lateral radiographs
and CT scans were obtained post-operatively and radiographs repeated
three weeks later. The anteversion of the acetabular component was
measured using the method described by Woo and Morrey and the ischiolateral
method described by Pulos et al and these were compared with the
results obtained from CT scans.Aims
Patients and Methods
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
Cardiac disease in patients with ankylosing spondylitis
(AS) has previously been studied but not in patients with a kyphosis
or in those who have undergone an operation to correct it. The aim of this study was to measure the post-operative changes
in cardiac function of patients with an AS kyphosis after pedicle
subtraction osteotomy (PSO). The original cohort consisted of 39 patients (33 men, six women).
Of these, four patients (two men, two women) were lost to follow-up
leaving 35 patients (31 men, four women) to study. The mean age
of the remaining patients was 37.4 years (22.3 to 47.8) and their
mean duration of AS was 17.0 years (4.6 to 26.4). Echocardiographic measurements,
resting heart rate (RHR), physical function score (PFS), and full-length
standing spinal radiographs were obtained before surgery and at
the two-year follow-up. The mean pre-operative RHR was 80.2 bpm (60.6 to 112.3) which
dropped to a mean of 73.7 bpm (60.7 to 90.6) at the two-year follow-up
(p = 0.0000). Of 15 patients with normal ventricular function pre-operatively,
two developed mild left ventricular diastolic dysfunction (LVDD)
at the two-year follow-up. Of 20 patients with mild LVDD pre-operatively
only five had this post-operatively. Overall, 15 patients had normal
LV diastolic function before their operation and 28 patients had
normal LV function at the two-year follow-up. The clinical improvement was 15 out of 20 (75.0%): cardiac function
in patients with AS whose kyphosis was treated by PSO was significantly
improved. Cite this article:
The interaction between surgical lighting and laminar airflow
is poorly understood. We undertook an experiment to identify any
effect contemporary surgical lights have on laminar flow and recommend
practical strategies to limit any negative effects. Neutrally buoyant bubbles were introduced into the surgical field
of a simulated setup for a routine total knee arthroplasty in a
laminar flow theatre. Patterns of airflow were observed and the
number of bubbles remaining above the surgical field over time identified.
Five different lighting configurations were assessed. Data were analysed
using simple linear regression after logarithmic transformation.Aims
Materials and Methods
We undertook a prospective non-randomised radiological study
to evaluate the preliminary results of using magnetically-controlled
growing rods (MAGEC System, Ellipse technology) to treat children
with early-onset scoliosis. Between January 2011 and January 2015, 19 children were treated
with magnetically-controlled growing rods (MCGRs) and underwent
distraction at three-monthly intervals. The mean age of our cohort
was 9.1 years (4 to 14) and the mean follow-up 22.4 months (5.1
to 35.2). Of the 19 children, eight underwent conversion from traditional growing
rods. Whole spine radiographs were carried out pre- and post-operatively:
image intensification was used during each lengthening in the outpatient
department. The measurements evaluated were Cobb angle, thoracic kyphosis,
proximal junctional kyphosis and spinal growth from T1 to S1.Aims
Patients and Methods
The purpose of the present study was to examine the long-term
fixation of a cemented fixed-bearing polished titanium tibial baseplate
(Genesis ll). Patients enrolled in a previous two-year prospective trial (n
= 35) were recalled at ten years. Available patients (n = 15) underwent
radiostereometric analysis (RSA) imaging in a supine position using
a conventional RSA protocol. Migration of the tibial component in
all planes was compared between initial and ten-year follow-up.
Outcome scores including the Knee Society Score, Western Ontario
and McMaster Universities Arthritis Index, 12-item Short Form Health
Survey, Forgotten Joint Score, and University of California, Los
Angeles Activity Score were recorded.Aims
Patients and Methods
Ideal placement of the acetabular component remains
elusive both in terms of defining and achieving a target. Our aim
is to help restore original anatomy by using the transverse acetabular
ligament (TAL) to control the height, depth and version of the component.
In the normal hip the TAL and labrum extend beyond the equator of
the femoral head and therefore, if the definitive acetabular component
is positioned such that it is cradled by and just deep to the plane
of the TAL and labrum and is no more than 4mm larger than the original
femoral head, the centre of the hip should be restored. If the face
of the component is positioned parallel to the TAL and psoas groove
the patient specific version should be restored. We still use the
TAL for controlling version in the dysplastic hip because we believe
that the TAL and labrum compensate for any underlying bony abnormality. The TAL should not be used as an aid to inclination. Worldwide,
>
75% of surgeons operate with the patient in the lateral decubitus
position and we have shown that errors in post-operative radiographic
inclination (RI) of >
50° are generally caused by errors in patient positioning.
Consequently, great care needs to be taken when positioning the
patient. We also recommend 35° of apparent operative inclination
(AOI) during surgery, as opposed to the traditional 45°. Cite this article:
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
Patellofemoral arthroplasty (PFA) has experienced significant
improvements in implant survivorship with second generation designs.
This has renewed interest in PFA as an alternative to total knee
arthroplasty (TKA) for younger active patients with isolated patellofemoral
osteoarthritis (PF OA). We analysed the cost-effectiveness of PFA We used a Markov transition state model to compare cost-effectiveness
between PFA and TKA. Simulated patients were aged 60 (base case)
and 50 years. Lifetime costs (2015 United States dollars), quality-adjusted
life year (QALY) gains and incremental cost-effectiveness ratio
(ICER) were calculated from a healthcare payer perspective. Annual rates
of revision were derived from the National Joint Registry for England,
Wales, Northern Ireland and the Isle of Man. Deterministic and probabilistic
sensitivity analysis was performed for all parameters against a
$50 000/QALY willingness to pay. Aims
Patients and Methods
Fractures of the distal femur can be challenging to manage and
are on the increase in the elderly osteoporotic population. Management
with casting or bracing can unacceptably limit a patient’s ability
to bear weight, but historically, operative fixation has been associated
with a high rate of re-operation. In this study, we describe the outcomes
of fixation using modern implants within a strategy of early return
to function. All patients treated at our centre with lateral distal femoral
locking plates (LDFLP) between 2009 and 2014 were identified. Fracture
classification and operative information including weight-bearing
status, rates of union, re-operation, failure of implants and mortality
rate, were recorded.Aims
Patients and Methods
Malrotation of the femoral component can result in post-operative complications in total knee arthroplasty (TKA), including patellar maltracking. Therefore, we used computational simulation to investigate the influence of femoral malrotation on contact stresses on the polyethylene (PE) insert and on the patellar button as well as on the forces on the collateral ligaments. Validated finite element (FE) models, for internal and external malrotations from 0° to 10° with regard to the neutral position, were developed to evaluate the effect of malrotation on the femoral component in TKA. Femoral malrotation in TKA on the knee joint was simulated in walking stance-phase gait and squat loading conditions.Objectives
Materials and Methods
