Aims

The aims of this study were to: 1) report on a cohort of skeletally mature patients with native hip and knee septic arthritis over a 14-year period; 2) to determine the rate of joint failure in patients who had experienced an episode of hip or knee septic arthritis; and 3) to assess the outcome following septic arthritis relative to the infecting organism, whether those patients infected by Staphylococcus aureus would be more likely to have adverse outcomes than those infected by other organisms.

Aims

To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability.

Aims. Hip resurfacing remains a potentially valuable surgical procedure for appropriately-selected patients with optimised implant choices. However, concern regarding high early failure rates continues to undermine confidence in use. A large contributor to failure is adverse local tissue reactions around metal-on-metal (MoM) bearing surfaces. Such phenomena have been well-explored around MoM total hip arthroplasties, but comparable data in equivalent hip resurfacing procedures is lacking. In order to define genetic predisposition, we performed a case-control study investigating the role of human leucocyte antigen (HLA) genotype in the development of pseudotumours around MoM hip resurfacings. Methods. A matched case-control study was performed using the prospectively-collected database at the host institution. In all, 16 MoM hip resurfacing 'cases' were identified as having symptomatic periprosthetic pseudotumours on preoperative metal artefact reduction sequence (MARS) MRI, and were subsequently histologically confirmed as high-grade aseptic lymphocyte-dominated vasculitis-associated lesions (ALVALs) at revision surgery. ‘Controls’ were matched by implant type in the absence of evidence of pseudotumour. Blood samples from all cases and controls were collected prospectively for high resolution genetic a nalysis targeting 11 separate HLA loci. Statistical significance was set at 0.10 a priori to determine the association between HLA genotype and pseudotumour formation, given the small sample size. Results. Using a previously-reported ALVAL classification, the majority of pseudotumour-positive caseswere found to have intermediate-grade group 2 (n = 10; 63%) or group 3 (n = 4; 25%) histological findings. Two further patients (13%) had high-grade group 4 lesions. HLA-DQB1*05:03:01 (p = 0.0676) and HLA-DRB1*14:54:01 (p = 0.0676) alleles were significantly associated with a higher risk of pseudotumour formation, while HLA-DQA1*03:01:01 (p = 0.0240), HLA-DRB1*04:04:01 (p = 0.0453), HLA-C*01:02:01 (p = 0.0453), and HLA-B*27:05:02 (p = 0.0855) were noted to confer risk reduction. Conclusion. These findings confirm the association between specific HLA genotypes and the risk of pseudotumour development around MoM hip resurfacings. Specifically, the two ‘at risk’ alleles (DQB1*05:03:01 and DRB1*14:54:01) may hold clinical value in preoperative screening and prospective surgical decision-making. Cite this article: Bone Jt Open 2023;4(3):182–187

Aims

This study aimed to explore the role of small colony variants (SCVs) of Staphylococcus aureus in intraosseous invasion and colonization in patients with periprosthetic joint infection (PJI).

Aims. Staphylococcus aureus is a major cause of septic arthritis, and in vitro studies suggest α haemolysin (Hla) is responsible for chondrocyte death. We used an in vivo murine joint model to compare inoculation with wild type S. aureus 8325-4 with a Hla-deficient strain DU1090 on chondrocyte viability, tissue histology, and joint biomechanics. The aim was to compare the actions of S. aureus Hla alone with those of the animal’s immune response to infection. Methods. Adult male C57Bl/6 mice (n = 75) were randomized into three groups to receive 1.0 to 1.4 × 10. 7. colony-forming units (CFUs)/ml of 8325-4, DU1090, or saline into the right stifle joint. Chondrocyte death was assessed by confocal microscopy. Histological changes to inoculated joints were graded for inflammatory responses along with gait, weight changes, and limb swelling. Results. Chondrocyte death was greater with 8325-4 (96.2% (SD 5.5%); p < 0.001) than DU1090 (28.9% (SD 16.0%); p = 0.009) and both were higher than controls (3.8% (SD 1.2%)). Histology revealed cartilage/bone damage with 8325-4 or DU1090 compared to controls (p = 0.010). Both infected groups lost weight (p = 0.006 for both) and experienced limb swelling (p = 0.043 and p = 0.018, respectively). Joints inoculated with bacteria showed significant alterations in gait cycle with a decreased stance phase, increased swing phase, and a corresponding decrease in swing speed. Conclusion. Murine joints inoculated with Hla-producing 8325-4 experienced significantly more chondrocyte death than those with DU1090, which lack the toxin. This was despite similar immune responses, indicating that Hla was the major cause of chondrocyte death. Hla-deficient DU1090 also elevated chondrocyte death compared to controls, suggesting a smaller additional deleterious role of the immune system on cartilage. Cite this article: Bone Joint Res 2022;11(9):669–678

Aims

The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells.

Aims

Rheumatoid arthritis (RA) is a systematic autoimmune disorder, characterized by synovial inflammation, bone and cartilage destruction, and disease involvement in multiple organs. Although numerous drugs are employed in RA treatment, some respond little and suffer from severe side effects. This study aimed to screen the candidate therapeutic targets and promising drugs in a novel method.

Aims

Osteoarthritis (OA) is the most prevalent joint disease. However, the specific and definitive genetic mechanisms of OA are still unclear.

Aims

There are limited published data detailing the volumetric material loss from tapers of conventional metal-on-polyethylene (MoP) total hip arthroplasties (THAs). Our aim was to address this by comparing the taper wear rates measured in an explanted cohort of the widely used Exeter THA with those measured in a group of metal-on-metal (MoM) THAs.

Objectives. Staphylococcus aureus (S. aureus) is the most commonly implicated organism in septic arthritis, a condition that may be highly destructive to articular cartilage. Previous studies investigating laboratory and clinical strains of S. aureus have demonstrated that potent toxins induced significant chondrocyte death, although the precise toxin or toxins that were involved was unknown. In this study, we used isogenic S. aureus mutants to assess the influence of alpha (Hla)-, beta (Hlb)-, and gamma (Hlg)-haemolysins, toxins considered important for the destruction of host tissue, on in situ bovine chondrocyte viability. Methods. Bovine cartilage explants were cultured with isogenic S. aureus mutants and/or their culture supernatants. Chondrocyte viability was then assessed within defined regions of interest in the axial and coronal plane following live- and dead-cell imaging using the fluorescent probes 5-chloromethylfluorescein diacetate and propidium iodide, respectively, and confocal laser-scanning microscopy. Results. Hla-producing mutants caused substantial chondrocyte death compared with the toxin-deficient control (Hla-Hlb-Hlg-), whilst mutants producing Hlb and Hlg in the absence of Hla induced minimal chondrocyte death. Coronal studies established that Hla-induced chondrocyte death started in the superficial zone of cartilage and spread to deeper layers, whereas Hlb and Hlg toxins were without significant effect. Conclusion. This study identified Hla as a highly potent S. aureus toxin that caused rapid chondrocyte death in bovine cartilage, with other toxins or metabolic products produced by the bacteria playing a minor role. The identification of Hla in mediating chondrocyte death may assist in the development of therapeutic strategies aimed at reducing the extent of cartilage damage during and after an episode of septic arthritis. Cite this article: I. D. M. Smith, K. M. Milto, C. J. Doherty, S. G. B. Amyes, A. H. R. W. Simpson, A. C. Hall. A potential key role for alpha-haemolysin of Staphylococcus aureus in mediating chondrocyte death in septic arthritis. Bone Joint Res 2018;7:457–467. DOI: 10.1302/2046-3758.77.BJR-2017-0165.R1

Aims

We sought to determine whether cobalt-chromium alloy (CoCr) femoral stem tapers (trunnions) wear more than titanium (Ti) alloy stem tapers (trunnions) when used in a large diameter (LD) metal-on-metal (MoM) hip arthroplasty system.

Objectives

The molecular mechanism of rheumatoid arthritis (RA) remains elusive. We conducted a protein-protein interaction network-based integrative analysis of genome-wide association studies (GWAS) and gene expression profiles of RA.

Objectives

An ongoing prospective study to investigate failing metal-on-metal hip prostheses was commenced at our centre in 2008. We report on the results of the analysis of the first consecutive 126 failed mated total hip prostheses from a single manufacturer.

Although success has been achieved with implantation of bone marrow mesenchymal stem cells (bMSCs) in degenerative discs, its full potential may not be achieved if the harsh environment of the degenerative disc remains. Axial distraction has been shown to increase hydration and nutrition. Combining both therapies may have a synergistic effect in reversing degenerative disc disease. In order to evaluate the effect of bMSC implantation, axial distraction and combination therapy in stimulating regeneration and retarding degeneration in degenerative discs, we first induced disc degeneration by axial loading in a rabbit model.

The rabbits in the intervention groups performed better with respect to disc height, morphological grading, histological scoring and average dead cell count. The groups with distraction performed better than those without on all criteria except the average dead cell count.

Our findings suggest that bMSC implantation and distraction stimulate regenerative changes in degenerative discs in a rabbit model.

Heterotopic ossification (HO) of the hip after injury to the central nervous system can lead to joint ankylosis. Surgery is usually delayed to avoid recurrence, even if the functional status is affected. We report a consecutive series of patients with HO of the hip after injury to the central nervous system who required surgery in a single, specialised tertiary referral unit. As was usual practice, they all underwent CT to determine the location of the HO and to evaluate the density of the femoral head and articular surface. The outcome of surgery was correlated with the pre-, peri- and post-operative findings.

In all, 183 hips (143 patients) were included of which 70 were ankylosed. A total of 25 peri-operative fractures of the femoral neck occurred, all of which arose in patients with ankylosed hips and were associated with intra-articular lesions in 18 and severe osteopenia of the femoral head in seven. All the intra-articular lesions were predicted by CT and strongly associated with post-operative complications.

The loss of the range of movement before ankylosis is a more important factor than the maturity of the HO in deciding the timing of surgery. Early surgical intervention minimises the development of intra-articular pathology, osteoporosis and the resultant complications without increasing the risk of recurrence of HO.