Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user’s cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma.
Periprosthetic joint infection (PJI) is a serious complication
of total hip arthroplasty (THA). Different bearing surface materials
have different surface properties and it has been suggested that
the choice of bearing surface may influence the risk of PJI after
THA. The objective of this meta-analysis was to compare the rate
of PJI between metal-on-polyethylene (MoP), ceramic-on-polyethylene
(CoP), and ceramic-on-ceramic (CoC) bearings. Electronic databases (Medline, Embase, Cochrane library, Web
of Science, and Cumulative Index of Nursing and Allied Health Literature)
were searched for comparative randomized and observational studies
that reported the incidence of PJI for different bearing surfaces.
Two investigators independently reviewed studies for eligibility, evaluated
risk of bias, and performed data extraction. Meta-analysis was performed
using the Mantel–Haenzel method and random-effects model in accordance
with methods of the Cochrane group.Aims
Patients and Methods
Ultraviolet (UV) light-mediated photofunctionalisation is known to improve osseointegration of pure titanium (Ti). However, histological examination of titanium alloy (Ti6Al4V), which is frequently applied in orthopaedic and dental surgery, has not yet been performed. This study examined the osseointegration of photofunctionalised Ti6Al4V implants. Ti and Ti6Al4V implants were treated with UV light, and the chemical composition and contact angle on the surfaces were evaluated to confirm photofunctionalisation. The implants were inserted into femurs in rats, and the rats were killed two or four weeks after the surgery. For histomorphometric analysis, both the bone–implant contact (BIC) ratio and the bone volume (BV) ratio were calculated from histological analysis and microcomputed tomography data.Objectives
Methods
During the last decades, several research groups have used bisphosphonates for local application to counteract secondary bone resorption after bone grafting, to improve implant fixation or to control bone resorption caused by bone morphogenetic proteins (BMPs). We focused on zoledronate (a bisphosphonate) due to its greater antiresorptive potential over other bisphosphonates. Recently, it has become obvious that the carrier is of importance to modulate the concentration and elution profile of the zoledronic acid locally. Incorporating one fifth of the recommended systemic dose of zoledronate with different apatite matrices and types of bone defects has been shown to enhance bone regeneration significantly
The optimal method of tibial component fixation remains uncertain
in total knee arthroplasty (TKA). Hydroxyapatite coatings have been
applied to improve bone ingrowth in uncemented designs, but may
only coat the directly accessible surface. As peri-apatite (PA)
is solution deposited, this may increase the coverage of the implant
surface and thereby fixation. We assessed the tibial component fixation
of uncemented PA-coated TKAs Patients were randomised to PA-coated or cemented TKAs. In 60
patients (30 in each group), radiostereometric analysis of tibial
component migration was evaluated as the primary outcome at baseline,
three months post-operatively and at one, two and five years. A
linear mixed-effects model was used to analyse the repeated measurements.Aims
Patients and 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 Intraosseous Transcutaneous Amputation Prosthesis (ITAP)
may improve quality of life for amputees by avoiding soft-tissue
complications associated with socket prostheses and by improving
sensory feedback and function. It relies on the formation of a seal
between the soft tissues and the implant and currently has a flange
with drilled holes to promote dermal attachment. Despite this, infection
remains a significant risk. This study explored alternative strategies
to enhance soft-tissue integration. The effect of ITAP pins with a fully porous titanium alloy flange
with interconnected pores on soft-tissue integration was investigated.
The flanges were coated with fibronectin-functionalised hydroxyapatite
and silver coatings, which have been shown to have an antibacterial
effect, while also promoting viable fibroblast growth Aims
Materials and Methods
Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis.Objectives
Methods
Objectives. The surface of pure titanium (Ti) shows decreased histocompatibility over time; this phenomenon is known as biological ageing. UV irradiation enables the reversal of biological ageing through photofunctionalisation, a physicochemical alteration of the titanium
Osteosynthesis of anterior pubic ramus fractures using one large-diameter screw can be challenging in terms of both surgical procedure and fixation stability. Small-fragment screws have the advantage of following the pelvic cortex and being more flexible. The aim of the present study was to biomechanically compare retrograde intramedullary fixation of the superior pubic ramus using either one large- or two small-diameter screws. A total of 12 human cadaveric hemipelvises were analysed in a matched pair study design. Bone mineral density of the specimens was 68 mgHA/cm3 (standard deviation (Objectives
Materials and Methods
To assess the extent of osteointegration in two designs of shoulder
resurfacing implants. Bony integration to the Copeland cylindrical
central stem design and the Epoca RH conical-crown design were compared. Implants retrieved from six patients in each group were pair-matched.
Mean time to revision surgery of Copeland implants was 37 months
(standard deviation (Aims
Patients and Methods
We wished to investigate the influence of metal debris exposure
on the subsequent immune response and resulting soft-tissue injury
following metal-on-metal (MoM) hip arthroplasty. Some reports have
suggested that debris generated from the head-neck taper junction
is more destructive than equivalent doses from metal bearing surfaces. We investigated the influence of the source and volume of metal
debris on chromium (Cr) and cobalt (Co) concentrations in corresponding
blood and hip synovial fluid samples and the observed agglomerated
particle sizes in excised tissues using multiple regression analysis
of prospectively collected data. A total of 199 explanted MoM hips
(177 patients; 132 hips female) were analysed to determine rates
of volumetric wear at the bearing surfaces and taper junctions. Aims
Patients 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.
Throughout the 20th Century, it has been postulated that the knee moves on the basis of a four-bar link mechanism composed of the cruciate ligaments, the femur and the tibia. As a consequence, the femur has been thought to roll back with flexion, and total knee arthroplasty (TKA) prostheses have been designed on this basis. Recent work, however, has proposed that at a position of between 0° and 120° the medial femoral condyle does not move anteroposteriorly whereas the lateral femoral condyle tends, but is not obliged, to roll back – a combination of movements which equates to tibial internal/ femoral external rotation with flexion. The aim of this paper was to assess if the articular geometry of the GMK Sphere TKA could recreate the natural knee movements The pattern of knee movement was studied in 15 patients (six male: nine female; one male with bilateral TKAs) with 16 GMK Sphere implants, at a mean age of 66 years (53 to 76) with a mean BMI of 30 kg/m2 (20 to 35). The motions of all 16 knees were observed using pulsed fluoroscopy during a number of weight-bearing and non-weight-bearing static and dynamic activities.Objectives
Methods
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:
Bactericidal levels of antibiotics are difficult
to achieve in infected total joint arthroplasty when intravenous antibiotics
or antibiotic-loaded cement spacers are used, but intra-articular
(IA) delivery of antibiotics has been effective in several studies.
This paper describes a protocol for IA delivery of antibiotics in
infected knee arthroplasty, and summarises the results of a pharmacokinetic
study and two clinical follow-up studies of especially difficult
groups: methicillin-resistant Cite this article:
A retrospective review was performed of patients
undergoing primary cementless total knee replacement (TKR) using
porous tantalum performed by a group of surgical trainees. Clinical
and radiological follow-up involved 79 females and 26 males encompassing
115 knees. The mean age was 66.9 years (36 to 85). Mean follow-up
was 7 years (2 to 11). Tibial and patellar components were porous
tantalum monoblock implants, and femoral components were posterior
stabilised (PS) in design with cobalt–chromium fibre mesh. Radiological
assessments were made for implant positioning, alignment, radiolucencies,
lysis, and loosening. There was 95.7% survival of implants. There
was no radiological evidence of loosening and no osteolysis found.
No revisions were performed for aseptic loosening. Average tibial
component alignment was 1.4° of varus (4°of valgus to 9° varus),
and 6.2° (3° anterior to 15° posterior) of posterior slope. Mean
femoral component alignment was 6.6° (1° to 11°) of valgus. Mean tibiofemoral
alignment was 5.6° of valgus (7° varus to 16° valgus). Patellar
tilt was a mean of 2.4° lateral (5° medial to 28° lateral). Patient
satisfaction with improvement in pain was 91%. Cementless TKR incorporating
porous tantalum yielded good clinical and radiological outcomes
at a mean of follow-up of seven-years. Cite this article:
We have assessed the different adhesive properties
of some of the most common bacteria associated with periprosthetic
joint infection on various types of ultra high molecular Weight
Polyethylene (UHMWPE). Quantitative Cite this article:
Our aim was to compare polylevolactic acid screws
with titanium screws when used for fixation of the distal tibiofibular
syndesmosis at mid-term follow-up. A total of 168 patients, with
a mean age of 38.5 years (18 to 72) who were randomly allocated
to receive either polylevolactic acid (n = 86) or metallic (n =
82) screws were included. The Baird scoring system was used to assess
the overall satisfaction and functional recovery post-operatively.
The demographic details and characteristics of the injury were similar
in the two groups. The mean follow-up was 55.8 months (48 to 66).
The Baird scores were similar in the two groups at the final follow-up.
Patients in the polylevolactic acid group had a greater mean dorsiflexion
(p = 0.011) and plantar-flexion of the injured ankles (p <
0.001).
In the same group, 18 patients had a mild and eight patients had
a moderate foreign body reaction. In the metallic groups eight had
mild and none had a moderate foreign body reaction (p <
0.001).
In total, three patients in the polylevolactic acid group and none
in the metallic group had heterotopic ossification (p = 0.246). We conclude that both screws provide adequate fixation and functional
recovery, but polylevolactic acid screws are associated with a higher
incidence of foreign body reactions. Cite this article: