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
Despite the earlier work on the bone cement interface in successful Charnley stems lasting 20 years, there is still controversy explaining success and failure of cemented stems. Is it possible to analyse cemented stems histo-pathologically over the whole length of the prosthesis, to show where loosening might start or where the osseous structure resists components' failure?. The purpose of this analysis was to develop histo-pathological procedures, to provide information about bony integration or fibrous encapsulation. This study took place over the past 12 years. Fourteen femoral stems from
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
INTRODUCTION. Adverse local tissue reactions (ALTR) and elevated serum metal ion levels secondary to fretting and corrosion at head-neck junctions in modular total hip arthroplasty (THA) designs have raised concern in recent years. Factors implicated in these processes include trunnion geometry, head-trunnion material couple, femoral head diameter, head length, force of head impaction at the time of surgery, and length of implantation. Our understanding of fretting and corrosion in vivo is based largely on the analysis of retrieved prostheses explanted for reasons related to clinical failure. Little is known about the natural history of head-neck tapers in well-functioning total hip replacements. We identified ten well-functioning THA prostheses retrieved at
Introduction. Previous studies of CoCr alloy femoral components for total knee arthroplasty (TKA) have identified 3. rd. body abrasive wear, and apparent inflammatory cell induced corrosion (ICIC) [1] as potential damage mechanisms. The association between observed surface damage on the femoral condyle and metal ion release into the surrounding tissues is currently unclear. The purpose of this study was to investigate the damage on the bearing surface in TKA femoral components recovered at
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
Bone ingrowth fixation of large diameter, beaded cobalt chromium cups is generally considered to be reliable but this is typically judged radiographically. To date, implant retrieval data of attached bone has been limited. This study evaluated correlations between the pre-revision radiographic appearance and the measured amount of bone attachment on one design of porous coated cup. Methods. Twenty-six monoblock, CoCr Birmingham Hip Resurfacing (BHR, Smith and Nephew, TN, USA) cups with macroscopic beads and hydroxyapatite coating were studied. Seventeen were revised for acetabular malposition with the remainder revised for femoral loosening (4), pain (1), infection (1), dislocation (1) or lysis (2). Median time to revision was 35 months (10 – 70 months). Ten patients were female; the median age of all patients was 54 years. The pre-revision radiographs were visually ranked for cup-bone integration as follows: 0 = none, 1 = < 50%, 2 = 50 – 75%, 3 = 76 – 95%, 4 = > 96% integration. Rankings were made for the superior and inferior aspects, without knowledge of the appearance of bone on the retrievals. The revised cups were photographed at an angle so the dome and the cup periphery were visualized. The area of bone in four equal segments in each of the superior and inferior aspects was measured with image analysis software. A probe was used to differentiate bone from soft tissue. Only bone that covered the beads was counted. Correlation coefficients were calculated for the radiographic and image analysis data. Results. Radiographically, most cups were assessed as having more than 50% of bone attachment and 7 cups were ranked as having almost total integration with bone. Only 2 cups were assessed radiographically as fully loose. Measured total bone attachment ranged from none to 55%. Superior and inferior percent ingrowth were highly correlated (corr=0.68, p<0.001) but there was no correlation between percent bone and x-ray rank (inferior corr=0.01, p=0.96; superior corr=0.23, p=0.26). There was no correlation between cup malpositioning as a reason for revision and x-ray integration ranking (superior p=0.34; inferior p=0.80). Discussion. Despite the radiographic appearance of good fixation, there was little or no correlation between percent area of actual bone attachment and x-ray appearance. One study limitation is the assumption that attached bone was indeed integrated with the beads as destructive sectioning was not done to verify this. Published
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:
Aims. This retrospective study aimed to determine the causes of in-hospital death after Neck of Femur (NOF) fracture in Southampton General Hospital (SGH) over a 6 year period, comparing the clinical cause of death with findings at post-mortem. A previous study showed discrepancies between pre-mortem clinical diagnosis and
Venous thromboembolic events, either deep vein thromboses or pulmonary emboli, are important complications in patients undergoing knee or hip arthroplasty. The purpose of this study was to evaluate the effectiveness of a mobile compression device (ActiveCare+S.F.T.®; Medical Compression Systems, Inc., Or Akiva, Israel) with or without aspirin compared with current pharmacology protocols for venous thromboembolism prophylaxis in patients undergoing elective primary unilateral lower extremity joint arthroplasty. A multicenter registry was established to capture the rate of symptomatic venous thromboemboli following primary lower extremity joint arthroplasty in 3,060 patients from ten sites including knee arthroplasty (1,551) or hip arthroplasty (1,509). All patients were 18 years of age or older with no known history of venous thromboembolism, coagulation disorder, or solid tumor. Use of the compression device began peri-operatively and continued for a minimum of ten days. Patients with symptoms of deep venous thrombosis or pulmonary embolism underwent duplex ultrasonography and/or spiral computed tomography. All patients were evaluated at three months post-operatively to document any evidence of deep venous thrombosis or pulmonary embolism. Of 3,060 patients, twenty-eight (0.92%) had venous thromboembolism (20 distal deep venous thromboses, 3 proximal deep venous thromboses, and 5 pulmonary emboli). One death occurred with no
Venous thromboembolic events, either deep vein thromboses or pulmonary emboli, are important complications in patients undergoing knee or hip arthroplasty. The purpose of this study was to evaluate the effectiveness of a mobile compression device (ActiveCare+S.F.T.®; Medical Compression Systems, Inc., Or Akiva, Israel) with or without aspirin compared with current pharmacology protocols for venous thromboembolism prophylaxis in patients undergoing elective primary unilateral lower extremity joint arthroplasty. A multicenter registry was established to capture the rate of symptomatic venous thromboemboli following primary lower extremity joint arthroplasty in 3,060 patients from ten sites including knee arthroplasty (1,551) or hip arthroplasty (1,509). All patients were eighteen years of age or older with no known history of venous thromboembolism, coagulation disorder, or solid tumor. Use of the compression device began perioperatively and continued for a minimum of ten days. Patients with symptoms of deep venous thrombosis or pulmonary embolism underwent duplex ultrasonography and/or spiral computed tomography. All patients were evaluated at three months postoperatively to document any evidence of deep venous thrombosis or pulmonary embolism. Of 3,060 patients, 28 (0.92%) had venous thromboembolism (20 distal deep venous thromboses, 3 proximal deep venous thromboses, and 5 pulmonary emboli). One death occurred with no
Venous thromboembolic events, either deep vein thromboses or pulmonary emboli, are important complications in patients undergoing knee or hip arthroplasty. The purpose of this study was to evaluate the effectiveness of a mobile compression device (ActiveCare+S.F.T.®; Medical Compression Systems, Inc., Or Akiva, Israel) with or without aspirin compared with current pharmacology protocols for venous thromboembolism prophylaxis in patients undergoing elective primary unilateral lower extremity joint arthroplasty. A multicenter registry was established to capture the rate of symptomatic venous thromboemboli following primary lower extremity joint arthroplasty in 3,060 patients from ten sites including knee arthroplasty (1,551) or hip arthroplasty (1,509). All patients were eighteen years of age or older with no known history of venous thromboembolism, coagulation disorder, or solid tumor. Use of the compression device began peri-operatively and continued for a minimum of ten days. Patients with symptoms of deep venous thrombosis or pulmonary embolism underwent duplex ultrasonography and/or spiral computed tomography. All patients were evaluated at three months post-operatively to document any evidence of deep venous thrombosis or pulmonary embolism. Of 3,060 patients, twenty-eight (0.92%) had venous thromboembolism (twenty distal deep venous thromboses, three proximal deep venous thromboses, and five pulmonary emboli). One death occurred with no
Venous thromboembolic events, either deep vein thromboses or pulmonary emboli, are important complications in patients undergoing knee or hip arthroplasty. The purpose of this study was to evaluate the effectiveness of a mobile compression device (ActiveCare+S.F.T.®; Medical Compression Systems, Inc., Or Akiva, Israel) with or without aspirin compared with current pharmacology protocols for venous thromboembolism prophylaxis in patients undergoing elective primary unilateral lower extremity joint arthroplasty. A multicenter registry was established to capture the rate of symptomatic venous thromboemboli following primary lower extremity joint arthroplasty in 3,060 patients from ten sites including knee arthroplasty (1,551) or hip arthroplasty (1,509). All patients were eighteen years of age or older with no known history of venous thromboembolism, coagulation disorder, or solid tumor. Use of the compression device began perioperatively and continued for a minimum of ten days. Patients with symptoms of deep venous thrombosis or pulmonary embolism underwent duplex ultrasonography and/or spiral computed tomography. All patients were evaluated at three months postoperatively to document any evidence of deep venous thrombosis or pulmonary embolism. Of 3,060 patients, twenty-eight (0.92%) had venous thromboembolism (twenty distal deep venous thromboses, three proximal deep venous thromboses, and five pulmonary emboli). One death occurred with no
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: