The treatment of bone loss in revision total
knee arthroplasty has evolved over the past decade. While the management
of small to moderate sized defects has demonstrated good results
with a variety of traditional techniques (cement and screws, small
metal augments, impaction bone grafting or modular stems), the treatment of
severe defects continues to be problematic. The use of a structural
allograft has declined in recent years due to an increased failure
rate with long-term follow-up and with the introduction of highly
porous metal augments that emphasise biological metaphyseal fixation.
Recently published mid-term results on the use of tantalum cones
in patients with severe bone loss has reaffirmed the success of
this treatment strategy. Cite this article:
Animal models have been developed that allow simulation of post-traumatic joint contracture. One such model involves contracture-forming surgery followed by surgical capsular release. This model allows testing of antifibrotic agents, such as rosiglitazone. A total of 20 rabbits underwent contracture-forming surgery. Eight weeks later, the animals underwent a surgical capsular release. Ten animals received rosiglitazone (intramuscular initially, then orally). The animals were sacrificed following 16 weeks of free cage mobilisation. The joints were tested biomechanically, and the posterior capsule was assessed histologically and via genetic microarray analysis.Aims
Methods
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:
The accurate reconstruction of hip anatomy and
biomechanics is thought to be important in achieveing good clinical
outcomes following total hip arthroplasty (THA). To this end some
newer hip designs have introduced further modularity into the design
of the femoral component such that neckshaft angle and anteversion,
which can be adjusted intra-operatively. The clinical effect of
this increased modularity is unknown. We have investigated the changes
in these anatomical parameters following conventional THA with a
prosthesis of predetermined neck–shaft angle and assessed the effect
of changes in the hip anatomy on clinical outcomes. In total, 44 patients (mean age 65.3 years (standard deviation
( The mean pre-operative neck–shaft angle was significantly increased
by 2.8° from 128° ( Cite this article:
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:
Partial knee arthroplasty (PKA), either medial
or lateral unicompartmental knee artroplasty (UKA) or patellofemoral arthroplasty
(PFA) are a good option in suitable patients and have the advantages
of reduced operative trauma, preservation of both cruciate ligaments
and bone stock, and restoration of normal kinematics within the
knee joint. However, questions remain concerning long-term survival.
The goal of this review article was to present the long-term results
of medial and lateral UKA, PFA and combined compartmental arthroplasty
for multicompartmental disease. Medium- and long-term studies suggest
reasonable outcomes at ten years with survival greater than 95% in
UKA performed for medial osteoarthritis or osteonecrosis, and similarly
for lateral Cite this article:
The aims of this study were to determine the
functional impact and financial burden of isolated and recurrent dislocation
after total hip arthroplasty (THA). Our secondary goal was to determine
whether there was a difference between patients who were treated
non-operatively and those who were treated operatively. We retrospectively reviewed 71 patients who had suffered dislocation
of a primary THA. Their mean age was 67 years (41 to 92) and the
mean follow-up was 3.8 years (2.1 to 8.2). Because patients with recurrent dislocation were three times
more likely to undergo operative treatment (p <
0.0001), they
ultimately had a significantly higher mean Harris Hip Score (HHS)
(p = 0.0001), lower mean Western Ontario and McMaster Universities
Arthritis Index (WOMAC) scores (p = 0.001) and a higher mean SF-12
score (p <
0.0001) than patients with a single dislocation. Likewise,
those who underwent operative treatment had a higher mean HHS (p
<
0.0001), lower mean WOMAC score (p <
0.0001) and a higher
mean SF-12 score (p <
0.0001) than those who were treated non-operatively. Recurrent dislocation and operative treatment increased costs
by 300% (£11 456;
p <
0.0001) and 40% (£5217; p <
0.0001), respectively. The operative treatment of recurrent dislocation results in significantly
better function than non-operative management. Moreover, the increase
in costs for operative treatment is modest compared with that of
non-operative measures. Cite this article:
The aim of our study was to describe the characteristics,
treatment, and outcomes of patients with periprosthetic joint infection
(PJI) and normal inflammatory markers after total knee arthroplasty
(TKA) and total hip arthroplasty (THA). In total 538 TKAs and 414 THAs underwent surgical treatment for
PJI and met the inclusion criteria. Pre-operative erythrocyte sedimentation
rate (ESR) and C-reactive protein level (CRP) were reviewed to identify
the seronegative cohort. An age- and gender-matched cohort was identified
from the remaining patients for comparison. Overall, 4% of confirmed
infections were seronegative (21 TKA and 17 THA). Of those who underwent
pre-operative aspiration, cultures were positive in 76% of TKAs
(n = 13) and 64% of THAs (n = 7). Cell count and differential were
suggestive of infection in 85% of TKA (n = 11) and all THA aspirates
(n = 5). The most common organism was coagulase-negative Cite this article:
Instability in flexion after total knee replacement
(TKR) typically occurs as a result of mismatched flexion and extension
gaps. The goals of this study were to identify factors leading to
instability in flexion, the degree of correction, determined radiologically,
required at revision surgery, and the subsequent clinical outcomes.
Between 2000 and 2010, 60 TKRs in 60 patients underwent revision
for instability in flexion associated with well-fixed components.
There were 33 women (55%) and 27 men (45%); their mean age was 65
years (43 to 82). Radiological measurements and the Knee Society
score (KSS) were used to assess outcome after revision surgery.
The mean follow-up was 3.6 years (2 to 9.8). Decreased condylar
offset (p <
0.001), distalisation of the joint line (p <
0.001)
and increased posterior tibial slope (p <
0.001) contributed
to instability in flexion and required correction at revision to regain
stability. The combined mean correction of posterior condylar offset
and joint line resection was 9.5 mm, and a mean of 5° of posterior
tibial slope was removed. At the most recent follow-up, there was
a significant improvement in the mean KSS for the knee and function
(both p <
0.001), no patient reported instability and no patient
underwent further surgery for instability. The following step-wise approach is recommended: reduction of
tibial slope, correction of malalignment, and improvement of condylar
offset. Additional joint line elevation is needed if the above steps
do not equalise the flexion and extension gaps. Cite this article:
Intact abductors of the hip play a crucial role
in preventing limping and are known to be damaged through the direct lateral
approach. The extent of trauma to the abductors after revision total
hip replacement (THR) is unknown. The aim of this prospective study
was to compare the pre- and post-operative status of the gluteus
medius muscle after revision THR. We prospectively compared changes
in the muscle and limping in 30 patients who were awaiting aseptic
revision THR and 15 patients undergoing primary THR. The direct
lateral approach as described by Hardinge was used for all patients.
MRI scans of the gluteus medius and functional analyses were recorded
pre-operatively and six months post-operatively. The overall mean
fatty degeneration of the gluteus medius increased from 35.8% (1.1
to 98.8) pre-operatively to 41% (1.5 to 99.8) after multiple revision
THRs (p = 0.03). There was a similar pattern after primary THR,
but with considerably less muscle damage (p = 0.001), indicating
progressive muscle damage. Despite an increased incidence of a positive
Trendelenburg sign following revision surgery (p = 0.03) there was
no relationship between the cumulative fatty degeneration in the
gluteus medius and a positive Trendelenburg sign (p = 0.26). The
changes associated with other surgical approaches to the hip warrant
investigation. Cite this article:
Instability after total knee replacement (TKR)
accounts for 10% to 22% of revision procedures. All patients who
present for evaluation of instability require a thorough history to
be taken and physical examination, as well as appropriate imaging.
Deep periprosthetic infection must be ruled out by laboratory testing
and an aspiration of the knee must be carried out. The three main
categories of instability include flexion instability, extension instability
(symmetric and asymmetric), and genu recurvatum. Most recently,
the aetiologies contributing to, and surgical manoeuvres required
to correct, flexion instability have been elucidated. While implant
design and patient-related factors may certainly contribute to the
aetiology, surgical technique is also a significant factor in all
forms of post-operative instability. Cite this article:
Substantial healthcare resources have been devoted
to computer navigation and patient-specific instrumentation systems
that improve the reproducibility with which neutral mechanical alignment
can be achieved following total knee replacement (TKR). This choice of
alignment is based on the long-held tenet that the alignment of
the limb post-operatively should be within 3° of a neutral mechanical
axis. Several recent studies have demonstrated no significant difference
in survivorship when comparing well aligned Review of the literature suggests that a neutral mechanical axis
remains the optimal guide to alignment. Cite this article:
The goal of this study was to determine whether intra-articular
administration of the potentially anti-fibrotic agent decorin influences
the expression of genes involved in the fibrotic cascade, and ultimately
leads to less contracture, in an animal model. A total of 18 rabbits underwent an operation on their right knees
to form contractures. Six limbs in group 1 received four intra-articular
injections of decorin; six limbs in group 2 received four intra-articular
injections of bovine serum albumin (BSA) over eight days; six limbs
in group 3 received no injections. The contracted limbs of rabbits
in group 1 were biomechanically and genetically compared with the
contracted limbs of rabbits in groups 2 and 3, with the use of a
calibrated joint measuring device and custom microarray, respectively.Objectives
Methods
Instability after arthroplasty of the shoulder
is difficult to correct surgically. Soft-tissue procedures and revision surgery
using unconstrained anatomical components are associated with a
high rate of failure. The purpose of this study was to determine
the results of revision of an unstable anatomical shoulder arthroplasty
to a reverse design prosthesis. Between 2004 and 2007, 33 unstable
anatomical shoulder arthroplasties were revised to a reverse design.
The mean age of the patients was 71 years (53 to 86) and their mean
follow-up was 42 months (25 to 71). The mean time to revision was
26 months (4 to 164). Pain scores improved significantly (pre-operative
visual analogue scale (VAS) of 7.2 ( Cite this article: