Trauma and orthopaedics is the largest of the
surgical specialties and yet attracts a disproportionately small
fraction of available national and international funding for health
research. With the burden of musculoskeletal disease increasing,
high-quality research is required to improve the evidence base for
orthopaedic practice. Using the current research landscape in the
United Kingdom as an example, but also addressing the international
perspective, we highlight the issues surrounding poor levels of
research funding in trauma and orthopaedics and indicate avenues
for improving the impact and success of surgical musculoskeletal
research. Cite this article:
High-intensity narrow-spectrum (HINS) light is
a novel violet-blue light inactivation technology which kills bacteria through
a photodynamic process, and has been shown to have bactericidal
activity against a wide range of species. Specimens from patients
with infected hip and knee arthroplasties were collected over a
one-year period (1 May 2009 to 30 April 2010). A range of these
microbial isolates were tested for sensitivity to HINS-light. During
testing, suspensions of the pathogens were exposed to increasing
doses of HINS-light (of 123mW/cm2 irradiance). Non-light exposed
control samples were also used. The samples were then plated onto
agar plates and incubated at 37°C for 24 hours before enumeration.
Complete inactivation (greater than 4-log10 reduction)
was achieved for all of the isolates. The typical inactivation curve
showed a slow initial reaction followed by a rapid period of inactivation.
The doses of HINS-light required ranged between 118 and 2214 J/cm2.
Gram-positive bacteria were generally found to be more susceptible
than Gram-negative. As HINS-light uses visible wavelengths, it can be safely used
in the presence of patients and staff. This unique feature could
lead to its possible use in the prevention of infection during surgery
and post-operative dressing changes. Cite this article:
The Capital Hip implant was a Charnley-based system which included a flanged and a roundback stem, both of which were available in stainless steel and titanium. The system was withdrawn from the market because of its inferior performance. However, all four of the designs did not produce poor rates of survival. Using a simulated-based, finite-element analysis, we have analysed the Capital Hip system. Our aim was to investigate whether our simulation was able to detect differences which could account for the varying survival between the Capital Hip designs, thereby further validating the simulation. We created finite-element models of reconstructions with the flanged and roundback Capital Hips. A loading history was applied representing normal walking and stair-climbing, while we monitored the formation of fatigue cracks in the cement. Corresponding to the clinical findings, our simulation was able to detect the negative effects of the titanium material and the flanged design in the Capital Hip system. Although improvements could be made by including the effect of the roughness of the surface of the stem, our study increased the value of the model as a predictive tool for determining failure of an implant.
We carried out a cross-sectional study with analysis of the demographic, clinical and laboratory characteristics of patients with metal-on-metal hip resurfacing, ceramic-on-ceramic and metal-on-polyethylene hip replacements. Our aim was to evaluate the relationship between metal-on-metal replacements, the levels of cobalt and chromium ions in whole blood and the absolute numbers of circulating lymphocytes. We recruited 164 patients (101 men and 63 women) with hip replacements, 106 with metal-on-metal hips and 58 with non-metal-on-metal hips, aged <
65 years, with a pre-operative diagnosis of osteoarthritis and no pre-existing immunological disorders. Laboratory-defined T-cell lymphopenia was present in13 patients (15%) (CD8+ lymphopenia) and 11 patients (13%) (CD3+ lymphopenia) with unilateral metal-on-metal hips. There were significant differences in the absolute CD8+ lymphocyte subset counts for the metal-on-metal groups compared with each control group (p-values ranging between 0.024 and 0.046). Statistical modelling with analysis of covariance using age, gender, type of hip replacement, smoking and circulating metal ion levels, showed that circulating levels of metal ions, especially cobalt, explained the variation in absolute lymphocyte counts for almost all lymphocyte subsets.
The re-establishment of vascularity is an early event in fracture healing; upregulation of angiogenesis may therefore promote the formation of bone. We have investigated the capacity of vascular endothelial growth factor (VEGF) to stimulate the formation of bone in an experimental atrophic nonunion model. Three groups of eight rabbits underwent a standard nonunion operation. This was followed by interfragmentary deposition of 100 μg VEGF, carrier alone or autograft. After seven weeks, torsional failure tests and callus size confirmed that VEGF-treated osteotomies had united whereas the carrier-treated osteotomies failed to unite. The biomechanical properties of the groups treated with VEGF and autograft were identical. There was no difference in bone blood flow. We considered that VEGF stimulated the formation of competent bone in an environment deprived of its normal vascularisation and osteoprogenitor cell supply. It could be used to enhance the healing of fractures predisposed to nonunion.