Delayed postoperative inoculation of orthopaedic implants with persistent wound drainage or bacterial seeding of a haematoma can result in periprosthetic joint infection (PJI). The aim of this in vivo study was to compare the efficacy of vancomycin powder with vancomycin-eluting calcium sulphate beads in preventing PJI due to delayed inoculation. A mouse model of PJI of the knee was used. Mice were randomized into groups with intervention at the time of surgery (postoperative day (POD) 0): a sterile control (SC; n = 6); infected control (IC; n = 15); systemic vancomycin (SV; n = 9); vancomycin powder (VP; n = 21); and vancomycin bead (VB; n = 19) groups. Delayed inoculation was introduced during an arthrotomy on POD 7 with 1 × 105 colony-forming units (CFUs) of a bioluminescent strain of Aims
Methods
The aim of this study was to analyze the prevalence of culture-negative periprosthetic joint infections (PJIs) when adequate methods of culture are used, and to evaluate the outcome in patients who were treated with antibiotics for a culture-negative PJI compared with those in whom antibiotics were withheld. A multicentre observational study was undertaken: 1,553 acute and 1,556 chronic PJIs, diagnosed between 2013 and 2018, were retrospectively analyzed. Culture-negative PJIs were diagnosed according to the Muskuloskeletal Infection Society (MSIS), International Consensus Meeting (ICM), and European Bone and Joint Society (EBJIS) definitions. The primary outcome was recurrent infection, and the secondary outcome was removal of the prosthetic components for any indication, both during a follow-up period of two years.Aims
Methods
Magnification of anteroposterior radiographs of the pelvis is variable. To improve the accuracy of templating, reliable and radiographer-friendly methods of scaling are necessary. We assessed two methods of scaling digital radiographs of the pelvis: placing a coin of known diameter in the plane of interest between the patient’s thighs, and using a caliper to measure the bony width of the pelvis. A total of 39 patients who had recently undergone hemiarthroplasty of the hip or total hip replacement were enrolled in the study. The accuracy of the methods was assessed by comparing the actual diameter of the head of the
When amputation just below the knee becomes necessary after extensive loss of bone from the tibia and of anterior soft tissue in the treatment of tumours, fractures or infection, the remaining proximal tibia may be too short for a below-knee
We have prospectively studied the outcome of infections associated with implants which were retained and treated using a standardised antimicrobial protocol. Over a period of four years, we studied 24 consecutive patients who had symptoms of infection for less than one year, a stable implant, no sinus tract and a known pathogen which was susceptible to recommended antimicrobial agents. The infections involved hip prostheses (14), knee prostheses (5), an internal fixation device (4), and an ankle
We investigated the long-term changes in the Harris Hip and Knee Society scores (HSS and KSS) to determine whether they result from overall functional decline rather than actual changes in the condition of the
The number of arthroplasties being undertaken
is expected to grow year on year, and periprosthetic joint infections will
be an increasing socioeconomic burden. The challenge to prevent
and eradicate these infections has resulted in the emergence of
several new strategies, which are discussed in this review. Cite this article:
Plots are an elegant and effective way to represent
data. At their best they encourage the reader and promote comprehension.
A graphical representation can give a far more intuitive feel to
the pattern of results in the study than a list of numerical data,
or the result of a statistical calculation. The temptation to exaggerate differences or relationships between
variables by using broken axes, overlaid axes, or inconsistent scaling
between plots should be avoided. A plot should be self-explanatory and not complicated. It should
make good use of the available space. The axes should be scaled
appropriately and labelled with an appropriate dimension. Plots are recognised statistical methods of presenting data and
usually require specialised statistical software to create them.
The statistical analysis and methods to generate the plots are as
important as the methodology of the study itself. The software,
including dates and version numbers, as well as statistical tests
should be appropriately referenced. Following some of the guidance provided in this article will
enhance a manuscript. Cite this article:
Periprosthetic joint infection (PJI) complicates
between 0.5% and 1.2% primary total hip arthroplasties (THAs) and
may have devastating consequences. The traditional assessment of
patients suffering from PJI has involved the serological study of
inflammatory markers and microbiological analysis of samples obtained
from the joint space. Treatment has involved debridement and revision
arthroplasty performed in either one or two stages. We present an update on the burden of PJI, strategies for its
diagnosis and treatment, the challenge of resistant organisms and
the need for definitive evidence to guide the treatment of PJI after
THA. Cite this article:
Currently, there is no animal model in which
to evaluate the underlying physiological processes leading to the heterotopic
ossification (HO) which forms in most combat-related and blast wounds.
We sought to reproduce the ossification that forms under these circumstances
in a rat by emulating patterns of injury seen in patients with severe
injuries resulting from blasts. We investigated whether exposure
to blast overpressure increased the prevalence of HO after transfemoral
amputation performed within the zone of injury. We exposed rats
to a blast overpressure alone (BOP-CTL), crush injury and femoral
fracture followed by amputation through the zone of injury (AMP-CTL)
or a combination of these (BOP-AMP). The presence of HO was evaluated
using radiographs, micro-CT and histology. HO developed in none
of nine BOP-CTL, six of nine AMP-CTL, and in all 20 BOP-AMP rats.
Exposure to blast overpressure increased the prevalence of HO. This model may thus be used to elucidate cellular and molecular
pathways of HO, the effect of varying intensities of blast overpressure,
and to evaluate new means of prophylaxis and treatment of heterotopic
ossification. Cite this article:
Implant-associated infection is a major source
of morbidity in orthopaedic surgery. There has been extensive research
into the development of materials that prevent biofilm formation,
and hence, reduce the risk of infection. Silver nanoparticle technology
is receiving much interest in the field of orthopaedics for its
antimicrobial properties, and the results of studies to date are
encouraging. Antimicrobial effects have been seen when silver nanoparticles are
used in trauma implants, tumour prostheses, bone cement, and also
when combined with hydroxyapatite coatings. Although there are promising
results with Cite this article:
Nanotechnology is the study, production and controlled
manipulation of materials with a grain size <
100 nm. At this
level, the laws of classical mechanics fall away and those of quantum
mechanics take over, resulting in unique behaviour of matter in
terms of melting point, conductivity and reactivity. Additionally,
and likely more significant, as grain size decreases, the ratio
of surface area to volume drastically increases, allowing for greater interaction
between implants and the surrounding cellular environment. This
favourable increase in surface area plays an important role in mesenchymal
cell differentiation and ultimately bone–implant interactions. Basic science and translational research have revealed important
potential applications for nanotechnology in orthopaedic surgery,
particularly with regard to improving the interaction between implants
and host bone. Nanophase materials more closely match the architecture
of native trabecular bone, thereby greatly improving the osseo-integration
of orthopaedic implants. Nanophase-coated prostheses can also reduce
bacterial adhesion more than conventionally surfaced prostheses.
Nanophase selenium has shown great promise when used for tumour
reconstructions, as has nanophase silver in the management of traumatic
wounds. Nanophase silver may significantly improve healing of peripheral
nerve injuries, and nanophase gold has powerful anti-inflammatory
effects on tendon inflammation. Considerable advances must be made in our understanding of the
potential health risks of production, implantation and wear patterns
of nanophase devices before they are approved for clinical use.
Their potential, however, is considerable, and is likely to benefit
us all in the future. Cite this article:
We compared the use of broth culture medium for
samples taken in theatre with the standard practice of placing tissue
samples in universal containers. A total of 67 consecutive patients
had standard multiple samples of deep tissue harvested at surgery
and distributed equally in theatre either to standard universal
containers or to broth culture medium. These samples were cultured
by direct and enrichment methods. The addition of broth in theatre to
standard practice led to an increase in sensitivity from 83% to
95% and an increase in negative predictive value from 77% to 91%.
Placing tissue samples directly into broth in the operating theatre
is a simple, inexpensive way to increase the sensitivity of cultures
from infected patients, and does not appear to compromise the specificity
of these cultures. Cite this article:
Peri-prosthetic infection remains a leading cause
of revision surgery. Recent publications from the American Musculoskeletal
Infection Society have sought to establish a definition of peri-prosthetic
infection based on clinical findings and laboratory investigations.
The limitations of their approach are discussed and an alternative
definition is proposed, which it is felt may better reflect the
uncertainties encountered in clinical practice.
Peri-prosthetic osteolysis and subsequent aseptic
loosening is the most common reason for revising total hip replacements.
Wear particles originating from the prosthetic components interact
with multiple cell types in the peri-prosthetic region resulting
in an inflammatory process that ultimately leads to peri-prosthetic
bone loss. These cells include macrophages, osteoclasts, osteoblasts
and fibroblasts. The majority of research in peri-prosthetic osteolysis
has concentrated on the role played by osteoclasts and macrophages.
The purpose of this review is to assess the role of the osteoblast
in peri-prosthetic osteolysis. In peri-prosthetic osteolysis, wear particles may affect osteoblasts
and contribute to the osteolytic process by two mechanisms. First,
particles and metallic ions have been shown to inhibit the osteoblast
in terms of its ability to secrete mineralised bone matrix, by reducing
calcium deposition, alkaline phosphatase activity and its ability
to proliferate. Secondly, particles and metallic ions have been
shown to stimulate osteoblasts to produce pro inflammatory mediators Cite this article:
We report the results of six trauma and orthopaedic
projects to Kenya in the last three years. The aims are to deliver both
a trauma service and teaching within two hospitals; one a district
hospital near Mount Kenya in Nanyuki, the other the largest public
hospital in Kenya in Mombasa. The Kenya Orthopaedic Project team
consists of a wide range of multidisciplinary professionals that
allows the experience to be shared across those specialties. A follow-up
clinic is held three months after each mission to review the patients.
To our knowledge there are no reported outcomes in the literature
for similar projects. A total of 211 operations have been performed and 400 patients
seen during the projects. Most cases were fractures of the lower
limb; we have been able to follow up 163 patients (77%) who underwent
surgical treatment. We reflect on the results so far and discuss
potential improvements for future missions.
Clinical, haematological or economic benefits of post-operative blood salvage with autologous blood re-transfusion have yet to be clearly demonstrated for primary total hip replacement. We performed a prospective randomised study to analyse differences in postoperative haemoglobin levels and homologous blood requirements in two groups of patients undergoing primary total hip replacement. A series of 158 patients was studied. In one group two vacuum drains were used and in the other the ABTrans autologous retransfusion system. A total of 58 patients (76%) in the re-transfusion group received autologous blood. There was no significant difference in the mean post-operative haemoglobin levels in the two groups. There were, however, significantly fewer patients with post-operative haemoglobin values less than 9.0 g/dl and significantly fewer patients who required transfusion of homologous blood in the re-transfusion group. There was also a small overall cost saving in this group.
The Control of Infection Committee at a specialist orthopaedic hospital prospectively collected data on all episodes of bacteriologically-proven deep infection arising after primary hip and knee replacements over a 15-year period from 1987 to 2001. There were 10 735 patients who underwent primary hip or knee replacement. In 34 of 5947 hip replacements (0.57%) and 41 of 4788 knee replacements (0.86%) a deep infection developed. The most common infecting micro-organism was coagulase-negative staphylococcus, followed by Of the infections, 29% (22) arose in the first three months following surgery, 35% between three months and one year (26), and 36% (27) after one year. Most cases were detected early and treated aggressively, with eradication of the infection in 96% (72). There was no significant change in the infection rate or type of infecting micro-organism over the course of this study. These results set a benchmark, and importantly emphasise that only 64% of peri-prosthetic infections arise within one year of surgery. These results also illustrate the advantages of conducting joint replacement surgery in the isolation of a specialist hospital.
We present seven patients with recurrent haemarthroses after total knee arthroplasty, caused by an inherent platelet function defect. These patients developed painful knee swelling, persistent bleeding and/or wound breakdown, a platelet factor 3 availability defect being identified in all cases. Surgical exploration, with joint debridement, lavage and synovectomy, was performed in four patients who did not improve with conservative therapy. Histopathological examination of synovium revealed a focal synovial reaction with histiocytic infiltration, and occasional foreign-body giant cells. One patient required an early revision because of aseptic loosening of their tibial component. The condition was treated by single-donor platelet transfusions with good results. The diagnosis, management, and relevance of this disorder are discussed.