We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE. Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality.Aims
Methods
A retrospective longitudinal study was conducted to compare directly volumetric wear of retrieved polyethylene inserts to predicted volumetric wear modelled from individual gait mechanics of total knee arthroplasty (TKA) patients. In total, 11 retrieved polyethylene tibial inserts were matched with gait analysis testing performed on those patients. Volumetric wear on the articular surfaces was measured using a laser coordinate measure machine and autonomous reconstruction. Knee kinematics and kinetics from individual gait trials drove computational models to calculate medial and lateral tibiofemoral contact paths and forces. Sliding distance along the contact path, normal forces and implantation time were used as inputs to Archard’s equation of wear to predict volumetric wear from gait mechanics. Measured and modelled wear were compared for each component.Aims
Methods
In order to address acetabular defects, porous metal revision acetabular components and augments have been developed, which require fixation to each other. The fixation technique that results in the smallest relative movement between the components, as well as its influence on the primary stability with the host bone, have not previously been determined. A total of 18 composite hemipelvises with a Paprosky IIB defect were implanted using a porous titanium 56 mm multihole acetabular component and 1 cm augment. Each acetabular component and augment was affixed to the bone using two screws, while the method of fixation between the acetabular component and augment varied for the three groups of six hemipelvises: group S, screw fixation only; group SC, screw plus cement fixation; group C, cement fixation only. The implanted hemipelvises were cyclically loaded to three different loading maxima (0.5 kN, 0.9 kN, and 1.8 kN).Objectives
Methods
The number of arthroplasties being performed
increases each year. Patients undergoing an arthroplasty are at
risk of venous thromboembolism (VTE) and appropriate prophylaxis
has been recommended. However, the optimal protocol and the best
agent to minimise VTE under these circumstances are not known. Although
many agents may be used, there is a difference in their efficacy
and the risk of bleeding. Thus, the selection of a particular agent relies
on the balance between the desire to minimise VTE and the attempt
to reduce the risk of bleeding, with its undesirable, and occasionally
fatal, consequences. Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis
following arthroplasty. Many studies have shown its efficacy in
minimising VTE under these circumstances. It is inexpensive and
well-tolerated, and its use does not require routine blood tests.
It is also a ‘milder’ agent and unlikely to result in haematoma
formation, which may increase both the risk of infection and the
need for further surgery. Aspirin is also unlikely to result in persistent
wound drainage, which has been shown to be associated with the use
of agents such as low-molecular-weight heparin (LMWH) and other
more aggressive agents. The main objective of this review was to summarise the current
evidence relating to the efficacy of aspirin as a VTE prophylaxis
following arthroplasty, and to address some of the common questions
about its use. There is convincing evidence that, taking all factors into account,
aspirin is an effective, inexpensive, and safe form of VTE following
arthroplasty in patients without a major risk factor for VTE, such
as previous VTE. Cite this article:
Inflammation of the retrocalcaneal bursa (RB) is a common clinical problem, particularly in professional athletes. RB inflammation is often treated with corticosteroid injections however a number of reports suggest an increased risk of Achilles tendon (AT) rupture. The aim of this cadaveric study was to describe the anatomical connections of the RB and to investigate whether it is possible for fluid to move from the RB into AT tissue. A total of 20 fresh-frozen AT specimens were used. In ten specimens, ink was injected into the RB. The remaining ten specimens were split into two groups to be injected with radiological contrast medium into the RB either with or without ultrasonography guidance (USG).Objectives
Methods
It is not clear whether anterior knee pain and osteoarthritis
(OA) of the patellofemoral joint (PFJ) are contraindications to
medial unicompartmental knee arthroplasty (UKA). Our aim was to
investigate the long-term outcome of a consecutive series of patients,
some of whom had anterior knee pain and PFJ OA managed with UKA. We assessed the ten-year functional outcomes and 15-year implant
survival of 805 knees (677 patients) following medial mobile-bearing
UKA. The intra-operative status of the PFJ was documented and, with
the exception of bone loss with grooving to the lateral side, neither
the clinical or radiological state of the PFJ nor the presence of
anterior knee pain were considered a contraindication. The impact
of radiographic findings and anterior knee pain was studied in a
subgroup of 100 knees (91 patients).Aims
Patients and Methods
Studies which consider the molecular mechanisms of degeneration and regeneration of cartilaginous tissues are seriously hampered by problematic ribonucleic acid (RNA) isolations due to low cell density and the dense, proteoglycan-rich extracellular matrix of cartilage. Proteoglycans tend to co-purify with RNA, they can absorb the full spectrum of UV light and they are potent inhibitors of polymerase chain reaction (PCR). Therefore, the objective of the present study is to compare and optimise different homogenisation methods and RNA isolation kits for an array of cartilaginous tissues. Tissue samples such as the nucleus pulposus (NP), annulus fibrosus (AF), articular cartilage (AC) and meniscus, were collected from goats and homogenised by either the MagNA Lyser or Freezer Mill. RNA of duplicate samples was subsequently isolated by either TRIzol (benchmark), or the RNeasy Lipid Tissue, RNeasy Fibrous Tissue, or Aurum Total RNA Fatty and Fibrous Tissue kits. RNA yield, purity, and integrity were determined and gene expression levels of type II collagen and aggrecan were measured by real-time PCR.Objectives
Materials and Methods
Pathological assessment of periprosthetic tissues is important, not only for diagnosis, but also for understanding the pathobiology of implant failure. The host response to wear particle deposition in periprosthetic tissues is characterised by cell and tissue injury, and a reparative and inflammatory response in which there is an innate and adaptive immune response to the material components of implant wear. Physical and chemical characteristics of implant wear influence the nature of the response in periprosthetic tissues and account for the development of particular complications that lead to implant failure, such as osteolysis which leads to aseptic loosening, and soft-tissue necrosis/inflammation, which can result in pseudotumour formation. The innate response involves phagocytosis of implant-derived wear particles by macrophages; this is determined by pattern recognition receptors and results in expression of cytokines, chemokines and growth factors promoting inflammation and osteoclastogenesis; phagocytosed particles can also be cytotoxic and cause cell and tissue necrosis. The adaptive immune response to wear debris is characterised by the presence of lymphoid cells and most likely occurs as a result of a cell-mediated hypersensitivity reaction to cell and tissue components altered by interaction with the material components of particulate wear, particularly metal ions released from cobalt-chrome wear particles. Cite this article: Professor N. A. Athanasou. The pathobiology and pathology of aseptic implant failure.
The place of thromboprophylaxis in arthroplasty surgery remains
controversial, with a challenging requirement to balance prevention
of potentially fatal venous thrombo-embolism with minimising wound-related
complications leading to deep infection. We compared the incidence
of fatal pulmonary embolism in patients undergoing elective primary
total hip arthroplasty (THA) between those receiving aspirin, warfarin
and low molecular weight heparin (LMWH) for the chemical component
of a multi-modal thromboprophylaxis regime. A prospective audit database was used to identify patients who
had died within 42 and 90 days of surgery respectively between April
2000 and December 2012. A case note review was performed to ascertain
the causes of death.Aims
Patients and Methods
Recently, the use of metal-on-metal articulations
in total hip arthroplasty (THA) has led to an increase in adverse
events owing to local soft-tissue reactions from metal ions and
wear debris. While the majority of these implants perform well,
it has been increasingly recognised that a small proportion of patients
may develop complications secondary to systemic cobalt toxicity
when these implants fail. However, distinguishing true toxicity
from benign elevations in cobalt ion levels can be challenging. The purpose of this two part series is to review the use of cobalt
alloys in THA and to highlight the following related topics of interest:
mechanisms of cobalt ion release and their measurement, definitions
of pathological cobalt ion levels, and the pathophysiology, risk factors
and treatment of cobalt toxicity. Historically, these metal-on-metal
arthroplasties are composed of a chromium-cobalt articulation. The release of cobalt is due to the mechanical and oxidative
stresses placed on the prosthetic joint. It exerts its pathological
effects through direct cellular toxicity. This manuscript will highlight the pathophysiology of cobalt
toxicity in patients with metal-on-metal hip arthroplasties. Take home message: Patients with new or evolving hip symptoms
with a prior history of THA warrant orthopaedic surgical evaluation.
Increased awareness of the range of systemic symptoms associated
with cobalt toxicity, coupled with prompt orthopaedic intervention, may
forestall the development of further complications. Cite this article:
We describe the routine imaging practices of
Level 1 trauma centres for patients with severe pelvic ring fractures, and
the interobserver reliability of the classification systems of these
fractures using plain radiographs and three-dimensional (3D) CT
reconstructions. Clinical and imaging data for 187 adult patients
(139 men and 48 women, mean age 43 years (15 to 101)) with a severe
pelvic ring fracture managed at two Level 1 trauma centres between July
2007 and June 2010 were extracted. Three experienced orthopaedic
surgeons classified the plain radiographs and 3D CT reconstruction
images of 100 patients using the Tile/AO and Young–Burgess systems.
Reliability was compared using kappa statistics. A total of
115 patients (62%) had plain radiographs as well as two-dimensional
(2D) CT and 3D CT reconstructions, 52 patients (28%) had plain films
only, 12 (6.4%) had 2D and 3D CT reconstructions images only, and
eight patients (4.3%) had no available images. The plain radiograph
was limited to an anteroposterior pelvic view. Patients without
imaging, or only plain films, were more severely injured. A total
of 72 patients (39%) were imaged with a pelvic binder Interobserver reliability for the Tile/AO (Kappa 0.10 to 0.17)
and Young–Burgess (Kappa 0.09 to 0.21) was low, and insufficient
for clinical and research purposes. Severe pelvic ring fractures are difficult to classify due to
their complexity, the increasing use of early treatment such as
with pelvic binders, and the absence of imaging altogether in important
patient sub-groups, such as those who die early of their injuries. Cite this article:
The aim of this study was to define the incidence
of venous thromboembolism (VTE) and risk factors for the development
of deep-vein thrombosis (DVT) after the resection of a musculoskeletal
tumour. A total of 94 patients who underwent resection of a musculoskeletal
tumour between January 2003 and December 2005 were prospectively
studied. There were 42 men and 52 women with a mean age of 54.4
years (18 to 86). All patients wore intermittent pneumatic compression
devices and graduated compression stockings. Ultrasound examination
of the lower limbs was conducted to screen for DVT between the fifth
and ninth post-operative days. DVT was detected in 21 patients (22%). Of these, two were symptomatic
(2%). One patient (1%) had a fatal pulmonary embolism. Patients
aged ≥ 70 years had an increased risk of DVT (p = 0.004). The overall incidence of DVT (both symptomatic and asymptomatic)
after resection of a musculoskeletal tumour with mechanical prophylaxis
was high. It seems that both mechanical and anticoagulant prophylaxis
is needed to prevent VTE in patients who have undergone the resection
of a musculoskeletal tumour. Cite this article:
The aims of this piece of work were to: 1) record the background
concentrations of blood chromium (Cr) and cobalt (Co) concentrations
in a large group of subjects; 2) to compare blood/serum Cr and Co
concentrations with retrieved metal-on-metal (MoM) hip resurfacings;
3) to examine the distribution of Co and Cr in the serum and whole
blood of patients with MoM hip arthroplasties; and 4) to further
understand the partitioning of metal ions between the serum and
whole blood fractions. A total of 3042 blood samples donated to the local transfusion
centre were analysed to record Co and Cr concentrations. Also, 91
hip resurfacing devices from patients who had given pre-revision
blood/serum samples for metal ion analysis underwent volumetric
wear assessment using a coordinate measuring machine. Linear regression analysis
was carried out and receiver operating characteristic curves were
constructed to assess the reliability of metal ions to identify
abnormally wearing implants. The relationship between serum and
whole blood concentrations of Cr and Co in 1048 patients was analysed
using Bland-Altman charts. This relationship was further investigated
in an Objectives
Methods
There is currently limited information available
on the benefits and risks of extended thromboprophylaxis after hip fracture
surgery. SAVE-HIP3 was a randomised, double-blind study conducted
to evaluate the efficacy and safety of extended thromboprophylaxis
with the ultra-low molecular-weight heparin semuloparin compared
with placebo in patients undergoing hip fracture surgery. After
a seven- to ten-day open-label run-in phase with semuloparin (20
mg once daily subcutaneously, initiated post-operatively), patients
were randomised to once-daily semuloparin (20 mg subcutaneously)
or placebo for 19 to 23 additional days. The primary efficacy endpoint
was a composite of any venous thromboembolism (VTE; any deep-vein
thrombosis and non-fatal pulmonary embolism) or all-cause death until
day 24 of the double-blind period. Safety parameters included major
and clinically relevant non-major bleeding, laboratory data, and
treatment-emergent adverse events (TEAEs). Extended thromboprophylaxis
with semuloparin demonstrated a relative risk reduction of 79% in
the rate of any VTE or all-cause death compared with placebo (3.9% Cite this article:
Symptomatic cobalt toxicity from a failed total
hip replacement is a rare but devastating complication. It has been reported
following revision of fractured ceramic components, as well as in
patients with failed metal-on-metal articulations. Potential clinical
findings include fatigue, weakness, hypothyroidism, cardiomyopathy,
polycythaemia, visual and hearing impairment, cognitive dysfunction,
and neuropathy. We report a case of an otherwise healthy 46-year-old
patient, who developed progressively worsening symptoms of cobalt
toxicity beginning approximately six months following synovectomy
and revision of a fractured ceramic-on-ceramic total hip replacement
to a metal-on-polyethylene bearing. The whole blood cobalt levels
peaked at 6521 µg/l. The patient died from cobalt-induced cardiomyopathy.
Implant retrieval analysis confirmed a loss of 28.3 g mass of the
cobalt–chromium femoral head as a result of severe abrasive wear
by ceramic particles embedded in the revision polyethylene liner.
Autopsy findings were consistent with heavy metal-induced cardiomyopathy. We recommend using new ceramics at revision to minimise the risk
of wear-related cobalt toxicity following breakage of ceramic components. Cite this article:
We investigated the incidence of and risk factors
for venous thromboembolism (VTE) following surgery of the shoulder
and elbow and assessed the role of thromboprophylaxis in upper limb
surgery. All papers describing VTE after shoulder and elbow surgery
published in the English language literature before 31 March 2012
were reviewed. A total of 14 papers were available for analysis,
most of which were retrospective studies and case series. The incidence
of VTE was 0.038% from 92 440 shoulder arthroscopic procedures,
0.52% from 42 261 shoulder replacements, and 0.64% from 4833 procedures
for fractures of the proximal humerus (open reduction and internal fixation
or hemiarthroplasty). The incidence following replacement of the
elbow was 0.26% from 2701 procedures. Diabetes mellitus, rheumatoid
arthritis and ischaemic heart disease were identified as the major
risk factors. The evidence that exists on thromboprophylaxis is based on level
III and IV studies, and we therefore cannot make any recommendations
on prophylaxis based on the current evidence. It seems reasonable
to adopt a multimodal approach that involves all patients receiving
mechanical prophylaxis, with chemical prophylaxis reserved for those
who are at high risk for VTE. Cite this article:
This article reviews the current knowledge of
the intervertebral disc (IVD) and its association with low back
pain (LBP). The normal IVD is a largely avascular and aneural structure
with a high water content, its nutrients mainly diffusing through
the end plates. IVD degeneration occurs when its cells die or become
dysfunctional, notably in an acidic environment. In the process
of degeneration, the IVD becomes dehydrated and vascularised, and
there is an ingrowth of nerves. Although not universally the case,
the altered physiology of the IVD is believed to precede or be associated
with many clinical symptoms or conditions including low back and/or
lower limb pain, paraesthesia, spinal stenosis and disc herniation. New treatment options have been developed in recent years. These
include biological therapies and novel surgical techniques (such
as total disc replacement), although many of these are still in
their experimental phase. Central to developing further methods
of treatment is the need for effective ways in which to assess patients
and measure their outcomes. However, significant difficulties remain
and it is therefore an appropriate time to be further investigating
the scientific basis of and treatment of LBP.
In order to compare the effect of oral apixaban
(a factor Xa inhibitor) with subcutaneous enoxaparin on major venous
thromboembolism and major and non-major clinically relevant bleeding
after total knee and hip replacement, we conducted a pooled analysis
of two previously reported double-blind randomised studies involving 8464
patients. One group received apixaban 2.5 mg twice daily (plus placebo
injection) starting 12 to 24 hours after operation, and the other
received enoxaparin subcutaneously once daily (and placebo tablets)
starting 12 hours (± 3) pre-operatively. Each regimen was continued
for 12 days ( Apixaban 2.5 mg twice daily is more effective than enoxaparin
40 mg once daily without increased bleeding.
We performed a meta-analysis of modern total
joint replacement (TJR) to determine the post-operative mortality and
the cause of death using different thromboprophylactic regimens
as follows: 1) no routine chemothromboprophylaxis (NRC); 2) Potent
anticoagulation (PA) (unfractionated or low-molecular-weight heparin, ximelagatran,
fondaparinux or rivaroxaban); 3) Potent anticoagulation combined
(PAC) with regional anaesthesia and/or pneumatic compression devices
(PCDs); 4) Warfarin (W); 5) Warfarin combined (WAC) with regional anaesthesia
and/or PCD; and 6) Multimodal (MM) prophylaxis, including regional
anaesthesia, PCDs and aspirin in low-risk patients. Cause of death
was classified as
Aseptic loosening of the acetabular component continues to be the most common indication for revision of total hip replacements in younger patients. Early in the evolution of the cemented hip, arthroplasty surgeons switched from removal to retention of the acetabular subchondral bone plate, theorising that unfavourable mechanical forces were the cause of loosening at the bone-cement interface. It is now known that the cause of aseptic loosening is probably biological rather than mechanical and removing the subchondral bone plate may enhance biological fixation of cement to bone. With this in mind, perhaps it is time to revive removal of the subchondral bone as a standard part of acetabular preparation.
