Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis.Objectives
Materials and Methods
Knee joint distraction (KJD) is a relatively new, knee-joint
preserving procedure with the goal of delaying total knee arthroplasty
(TKA) in young and middle-aged patients. We present a randomised
controlled trial comparing the two. The 60 patients ≤ 65 years with end-stage knee osteoarthritis
were randomised to either KJD (n = 20) or TKA (n = 40). Outcomes
were assessed at baseline, three, six, nine, and 12 months. In the
KJD group, the joint space width (JSW) was radiologically assessed,
representing a surrogate marker of cartilage thickness.Aims
Patients and Methods
Many aspects of total knee arthroplasty have
changed since its inception. Modern prosthetic design, better fixation techniques,
improved polyethylene wear characteristics and rehabilitation, have
all contributed to a large change in revision rates. Arthroplasty
patients now expect longevity of their prostheses and demand functional
improvement to match. This has led to a re-examination of the long-held
belief that mechanical alignment is instrumental to a successful
outcome and a focus on restoring healthy joint kinematics. A combination
of kinematic restoration and uncemented, adaptable fixation may
hold the key to future advances. Cite this article:
The role of high tibial osteotomy (HTO) is being questioned by
the use of unicompartmental knee arthroplasty (UKA) in the treatment
of medial compartment femorotibial osteoarthritis. Our aim was to
compare the outcomes of revision HTO or UKA to a total knee arthroplasty
(TKA) using computer-assisted surgery in matched groups of patients. We conducted a retrospective study to compare the clinical and
radiological outcome of patients who underwent revision of a HTO
to a TKA (group 1) with those who underwent revision of a medial
UKA to a TKA (group 2). All revision procedures were performed using
computer-assisted surgery. We extracted these groups of patients
from our database. They were matched by age, gender, body mass index,
follow-up and pre-operative functional score. The outcomes included
the Knee Society Scores (KSS), radiological outcomes and the rate
of further revision.Aims
Patients and Methods
Fractures around total knee arthroplasties pose
a significant surgical challenge. Most can be managed with osteosynthesis
and salvage of the replacement. The techniques of fixation of these
fractures and revision surgery have evolved and so has the assessment
of outcome. This specialty update summarises the current evidence
for the classification, methods of fixation, revision surgery and
outcomes of the management of periprosthetic fractures associated
with total knee arthroplasty. Cite this article:
This study demonstrates a significant correlation
between the American Knee Society (AKS) Clinical Rating System and
the Oxford Knee Score (OKS) and provides a validated prediction
tool to estimate score conversion. A total of 1022 patients were prospectively clinically assessed
five years after TKR and completed AKS assessments and an OKS questionnaire.
Multivariate regression analysis demonstrated significant correlations between
OKS and the AKS knee and function scores but a stronger correlation
(r = 0.68, p <
0.001) when using the sum of the AKS knee and
function scores. Addition of body mass index and age (other statistically
significant predictors of OKS) to the algorithm did not significantly
increase the predictive value. The simple regression model was used to predict the OKS in a
group of 236 patients who were clinically assessed nine to ten years
after TKR using the AKS system. The predicted OKS was compared with
actual OKS in the second group. Intra-class correlation demonstrated
excellent reliability (r = 0.81, 95% confidence intervals 0.75 to
0.85) for the combined knee and function score when used to predict
OKS. Our findings will facilitate comparison of outcome data from
studies and registries using either the OKS or the AKS scores and
may also be of value for those undertaking meta-analyses and systematic
reviews. Cite this article:
The use of robotics in arthroplasty surgery is expanding rapidly as improvements in the technology evolve. This article examines current evidence to justify the usage of robotics, as well as the future potential in this emerging field.
We compared the outcome of total hip arthroplasty (THA) in obese
patients who previously underwent bariatric surgery and those who
did not, in a matched cohort study. There were 47 THAs in the bariatric group (42 patients), and
94 THAs in the comparison group (92 patients). The mean age of the
patients was 57 years in both groups (24 to 79) and 57% of the patients
in both groups were women. The mean time between bariatric surgery
and THA was five years (four months to 12 years) in the bariatric group.
The mean follow-up after THA was three years (2 to 9). Aims
Patients and Methods
The interest in unicompartmental knee arthroplasty (UKA) for
medial osteoarthritis has increased rapidly but the long-term follow-up
of the Oxford UKAs has yet to be analysed in non-designer centres.
We have examined our ten- to 15-year clinical and radiological follow-up
data for the Oxford Phase III UKAs. Between January 1999 and January 2005 a total of 138 consecutive
Oxford Phase III arthroplasties were performed by a single surgeon
in 129 patients for medial compartment osteoarthritis (71 right
and 67 left knees, mean age 72.0 years (47 to 91), mean body mass
index 28.2 (20.7 to 52.2)). Both clinical data and radiographs were
prospectively recorded and obtained at intervals. Of the 129 patients,
32 patients (32 knees) died, ten patients (12 knees) were not able
to take part in the final clinical and radiological assessment due
to physical and mental conditions, but via telephone interview it
was confirmed that none of these ten patients (12 knees) had a revision
of the knee arthroplasty. One patient (two knees) was lost to follow-up.Aims
Patients and Methods
There is uncertainty regarding the optimal means of thromboprophylaxis
following total hip and knee arthroplasty (THA, TKA). This systematic
review presents the evidence for acetylsalicylic acid (aspirin)
as a thromboprophylactic agent in THA and TKA and compares it with
other chemoprophylactic agents. A search of literature published between 2004 and 2014 was performed
in accordance with Preferred Reporting Items for Systematic Reviews
and Meta-Analyses guidelines. A total of 13 studies were eligible
for inclusion.Aims
Materials and Methods
To determine whether there is any difference in infection rate
at 90 days between trauma operations performed in laminar flow and
plenum ventilation, and whether infection risk is altered following
the installation of laminar flow (LF). We assessed the impact of plenum ventilation (PV) and LF on the
rate of infection for patients undergoing orthopaedic trauma operations.
All NHS hospitals in England with a trauma theatre(s) were contacted
to identify the ventilation system which was used between April
2008 and March 2013 in the following categories: always LF, never
LF, installed LF during study period (subdivided: before, during
and after installation) and unknown. For each operation, age, gender,
comorbidity, socio-economic deprivation, number of previous trauma
operations and surgical site infection within 90 days (SSI90) were
extracted from England’s national hospital administrative Hospital
Episode Statistics database. Crude and adjusted odds ratios (OR)
were used to compare ventilation groups using hierarchical logistic
regression. Subanalysis was performed for hip hemiarthroplasties.Aims
Patients and Methods
Anatomical total knee arthroplasty alignment
The February 2015 Knee Roundup360 looks at: Intra-operative sensors for knee balance; Mobile bearing no advantage; Death and knee replacement: a falling phenomenon; The swings and roundabouts of unicompartmental arthroplasty; Regulation, implants and innovation; The weight of arthroplasty responsibility!; BMI in arthroplasty
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
Obesity is a worldwide epidemic that has both
economic and health implications of enormous consequence. The obese
patients tend to have earlier symptoms related to osteoarthritis,
more peri-operative medical problems, higher rates of infection
and more technical difficulties intra-operatively following hip
and knee arthroplasty. Nevertheless, these patients have good long-term
clinical outcomes and implant survival rates and are often some of
the most satisfied patients after joint arthroplasty. Therefore,
obese patients should not be denied surgery based on their weight
alone. Cite this article:
A key to the success of revision total knee arthroplasty
(TKA) is a safe surgical approach using an exposure that minimises
complications. In most patients, a medial parapatellar arthrotomy
with complete synovectomy is sufficient. If additional exposure
is needed, a quadriceps snip performed through the quadriceps tendon
often provides the additional exposure required. It is simple to
perform and does not alter the post-operative rehabilitative protocol.
In rare cases, in which additional exposure is needed, or when removal
of a cemented long-stemmed tibial component is required, a tibial
tubercle osteotomy (TTO) may be used. Given the risk of post-operative
extensor lag, a V-Y quadricepsplasty is rarely indicated and usually
considered only if TTO is not possible. Cite this article:
Collateral ligament release is advocated in total
knee arthroplasty (TKA) to deal with significant coronal plane deformities,
but is also associated with significant disadvantages. We describe steps to avoid release of the collateral (superficial
medial and lateral collateral) ligaments during TKA in severely
deformed knees, while correcting deformity and balancing the knee. Cite this article:
