The results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular flexion and extension gaps sought with gap-balanced mechanical axis total knee arthroplasty (MATKA). This paper aims to address the following questions: 1) what factors determine coronal joint congruence as measured on standing radiographs?; 2) is flexion gap asymmetry produced with KA?; 3) does lateral flexion gap laxity affect outcomes?; 4) is lateral flexion gap laxity associated with lateral extension gap laxity?; and 5) can consistent ligament balance be produced without releases? A total of 192 KTKAs completed by a single surgeon using a computer-assisted technique were followed for a mean of 3.5 years (2 to 5). There were 116 male patients (60%) and 76 female patients (40%) with a mean age of 65 years (48 to 88). Outcome measures included intraoperative gap laxity measurements and component positions, as well as joint angles from postoperative three-foot standing radiographs. Patient-reported outcome measures (PROMs) were analyzed in terms of alignment and balance: EuroQol (EQ)-5D visual analogue scale (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS Joint Replacement (JR), and Oxford Knee Score (OKS).Aims
Patients and Methods
Prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty. Non-contact induction heating of metal implants is a new and emerging treatment for PJI. However, there may be concerns for potential tissue necrosis. It is thought that segmental induction heating can be used to control the thermal dose and to limit collateral thermal injury to the bone and surrounding tissues. The purpose of this study was to determine the thermal dose, for commonly used metal implants in orthopaedic surgery, at various distances from the heating centre (HC). Commonly used metal orthopaedic implants (hip stem, intramedullary nail, and locking compression plate (LCP)) were heated segmentally using an induction heater. The thermal dose was expressed in cumulative equivalent minutes at 43°C (CEM43) and measured with a thermal camera at several different distances from the HC. A value of 16 CEM43 was used as the threshold for thermal damage in bone.Objectives
Methods
The purpose of this study was to evaluate spinopelvic mechanics from standing and sitting positions in subjects with and without femoroacetabular impingement (FAI). We hypothesize that FAI patients will experience less flexion at the lumbar spine and more flexion at the hip whilst changing from standing to sitting positions than subjects without FAI. This increase in hip flexion may contribute to symptomatology in FAI. Male subjects were prospectively enrolled to the study (n = 20). Mean age was 31 years old (22 to 41). All underwent clinical examination, plain radiographs, and dynamic imaging using EOS. Subjects were categorized into three groups: non-FAI (no radiographic or clinical FAI or pain), asymptomatic FAI (radiographic and clinical FAI but no pain), and symptomatic FAI (patients with both pain and radiographic FAI). FAI was defined as internal rotation less than 15° and alpha angle greater than 60°. Subjects underwent standing and sitting radiographs in order to measure spine and femoroacetabular flexion.Aims
Patients and Methods
The aim of this study was to evaluate the accuracy of implant placement when using robotic assistance during total hip arthroplasty (THA). A total of 20 patients underwent a planned THA using preoperative CT scans and robotic-assisted software. There were nine men and 11 women (n = 20 hips) with a mean age of 60.8 years (Aims
Patients and Methods
Tibiofemoral alignment is important to determine the rate of
progression of osteoarthritis and implant survival after total knee
arthroplasty (TKA). Normally, surgeons aim for neutral tibiofemoral
alignment following TKA, but this has been questioned in recent
years. The aim of this study was to evaluate whether varus or valgus
alignment indeed leads to increased medial or lateral tibiofemoral
forces during static and dynamic weight-bearing activities. Tibiofemoral contact forces and moments were measured in nine
patients with instrumented knee implants. Medial force ratios were
analysed during nine daily activities, including activities with
single-limb support (e.g. walking) and double-limb support (e.g.
knee bend). Hip-knee-ankle angles in the frontal plane were analysed
using full-leg coronal radiographs. 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 aims of this study were to quantify health state utility
values (HSUVs) after a tibial fracture, investigate the effect of
complications, to determine the trajectory in HSUVs that result
in these differences and to quantify the quality-adjusted life years
(QALYs) experienced by patients. This is an analysis of 2138 tibial fractures enrolled in the
Fluid Lavage of Open Wounds (FLOW) and Study to Prospectively Evaluate
Reamed Intramedullary Nails in Patients with Tibial Fractures (SPRINT)
trials. Patients returned for follow-up at two and six weeks and
three, six, nine and 12 months. Short-Form Six-Dimension (SF-6D) values
were calculated and used to calculate QALYs.Aims
Patients and Methods
This study assessed the association of classes of body mass index
in kg/m2 (classified as normal weight 18.5 kg/m2 to
24.9 kg/m2, overweight 25.0 kg/m2 to 29.9
kg/m2, and obese ≥ 30.0 kg/m2) with short-term
complications and functional outcomes three to six years post-operatively
for closed ankle fractures. We performed a historical cohort study with chart review of 1011
patients who were treated for ankle fractures by open reduction
and internal fixation in two hospitals, with a follow-up postal
survey of 959 of the patients using three functional outcome scores.Aims
Patients and Methods
Anatomical atlases document classical safe corridors for the
placement of transosseous fine wires through the calcaneum during
circular frame external fixation. During this process, the posterior
tibial neurovascular bundle (PTNVB) is placed at risk, though this
has not been previously quantified. We describe a cadaveric study
to investigate a safe technique for posterolateral to anteromedial
fine wire insertion through the body of the calcaneum. A total of 20 embalmed cadaveric lower limbs were divided into
two groups. Wires were inserted using two possible insertion points
and at varying angles. In Group A, wires were inserted one-third
along a line between the point of the heel and the tip of the lateral
malleolus while in Group B, wires were inserted halfway along this
line. Standard dissection techniques identified the structures at
risk and the distance of wires from neurovascular structures was measured.
The results from 19 limbs were subject to analysis.Aims
Materials and Methods
The aim of this study was to determine whether the rates of revision
for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle
components varied according to the year of the initial operation,
and compare these with the rates of revision for other designs of
MoM THA. Data from the National Joint Registry for England and Wales included
36 mm MoM THAs with Pinnacle acetabular components which were undertaken
between 2003 and 2012 with follow-up for at least five years (n
= 10 776) and a control group of other MoM THAs (n = 13 817). The
effect of the year of the primary operation on all-cause rates of revision
was assessed using Cox regression and interrupted time-series analysis.Aims
Patients and Methods
In patients where the proximal femur shows gross deformity due
to degenerative changes or fracture, the contralateral femur is
often used to perform preoperative templating for hip arthroplasty.
However, femurs may not be symmetrical: the aim of this study was
to determine the degree of variation between hips in healthy individuals and
to determine whether it is affected by demographic parameters. CT-scan based modelling was used to examine the pelvis and bilateral
femurs of 345 patients (211 males, 134 women; mean age 62 years
(standard deviation (Aims
Materials and Methods
Gastrocnemius tightness predisposes to musculoskeletal pathology
and may require surgical treatment. However, it is not clear what
proportion of patients with foot and ankle pathology have clinically
significant gastrocnemius tightness. The aim of this study was to
compare the prevalence and degree of gastrocnemius tightness in
a control group of patients with a group of patients with foot and
ankle pathology. This prospective, case-matched, observational study compared
gastrocnemius tightness, as assessed by the lunge test, in a control
group and a group with foot and ankle pathology. Gastrocnemius tightness
was calculated as the difference in dorsiflexion of the ankle with
the knee extended and flexed.Aims
Patients and Methods
Early evidence has emerged suggesting that ceramic-on-ceramic
articulations induce a different tissue reaction to ceramic-on-polyethylene
and metal-on-metal bearings. Therefore, the aim of this study was
to investigate the tissue reaction and cellular response to ceramic
total hip arthroplasty (THA) materials We investigated tissue collected at revision surgery from nine
ceramic-on-ceramic articulations. we compared our findings with
tissue obtained from five metal-on-metal THA revisions, four ceramic-on-polyethylene
THAs, and four primary osteoarthritis synovial membranes. The latter
were analyzed to assess the amount of tissue fibrosis that might
have been present at the time of implantation to enable evaluation,
in relation to implantation time, of any subsequent response in
the tissues.Aims
Patients and 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
This study investigated the influence of body mass index (BMI)
on the post-operative fall in the level of haemoglobin (Hb), length
of hospital stay (LOS), 30-day re-admission rate, functional outcome
and quality of life, two years after total knee arthroplasty (TKA). A total of 7733 patients who underwent unilateral primary TKA
between 2001 and 2010 were included. The mean age was 67 years (30
to 90). There were 1421 males and 6312 females. The patients were
categorised into three groups: BMI <
25.0 kg/m2 (normal);
BMI between 25.0 and 39.9 kg/m2 (obese); and BMI ≥ 40.0
kg/m2 (morbidly obese).Aims
Patients and Methods
The primary aim of this study was to define and quantify three
new measurements to indicate the position of the greater trochanter.
Secondary aims were to define ‘functional antetorsion’ as it relates
to abductor function in populations both with and without torsional
abnormality. Three new measurements, functional antetorsion, posterior tilt,
and posterior translation of the greater trochanter, were assessed
from 61 CT scans of cadaveric femurs, and their reliability determined.
These measurements and their relationships were also evaluated in
three groups of patients: a control group (n = 22), a ‘high-antetorsion’ group
(n = 22) and a ‘low-antetorsion’ group (n = 10).Aims
Patients and Methods
Recently, there has been considerable interest in quantifying
the associations between bony abnormalities around and in the hip
joint and osteoarthritis (OA). Our aim was to investigate the relationships
between acetabular undercoverage, acetabular overcoverage, and femoroacetabular
impingement (FAI) with OA of the hip, which currently remain controversial. A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd
osteological collection were obtained. Femoral head volume (FHV),
acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha
angle and anterior femoral neck offset (AFNO) were measured. A validated
grading system was used to quantify OA of the hip as minimal, moderate,
or severe. Multiple linear and multinomial logistic regression were
used to determine the factors that correlated independently with
the FHV, AV, and the FHV/AV ratio. Aims
Materials and Methods
The Bereiter trochleoplasty has been used in our unit for 12
years to manage recurrent patellar instability in patients with
severe trochlea dysplasia. The aim of this study was to document
the outcome of a large consecutive cohort of patients who have undergone
this operation. Between June 2002 and August 2013, 214 consecutive trochleoplasties
were carried out in 185 patients. There were 133 women and 52 men
with a mean age of 21.3 years (14 to 38). All patients were offered
yearly clinical and radiological follow-up. They completed the following
patient reported outcome scores (PROMs): International Knee Documentation
Committee subjective scale, the Kujala score, the Western Ontario
and McMaster Universities Arthritis Index score and the short-form
(SF)-12. Aims
Patients and Methods
The aim of this study was to compare the effectiveness of a femoral
nerve block and a periarticular infiltration in the management of
early post-operative pain after total knee arthroplasty (TKA). A pragmatic, single centre, two arm parallel group, patient blinded,
randomised controlled trial was undertaken. All patients due for
TKA were eligible. Exclusion criteria included contraindications
to the medications involved in the study and patients with a neurological
abnormality of the lower limb. Patients received either a femoral
nerve block with 75 mg of 0.25% levobupivacaine hydrochloride around
the nerve, or periarticular infiltration with 150 mg of 0.25% levobupivacaine
hydrochloride, 10 mg morphine sulphate, 30 mg ketorolac trometamol
and 0.25 mg of adrenaline all diluted with 0.9% saline to make a
volume of 150 ml.Aims
Patients and Methods
