Introduction

The treatment of posterior malleolar fractures is developing. Mason and Molloy (Foot Ankle Int. 2017 Nov;38(11):1229-1235) identified only 49% of posterior malleolar rotational pilon type fractures had syndesmotic instabilities. This was against general thinking that fixation of such a fragment would stabilize the syndesmosis.

Aims

Obesity is associated with an increased risk of hip osteoarthritis, resulting in an increased number of total hip arthroplasties (THAs) performed annually. This study examines the peri- and postoperative outcomes of morbidly obese (MO) patients (BMI ≥ 40 kg/m²) compared to healthy weight (HW) patients (BMI 18.5 to < 25 kg/m²) who underwent a THA using the anterior-based muscle-sparing (ABMS) approach.

Nanotopographical cues on Ti surfaces have been shown to elicit different cell responses such as differentiation and selective growth. Bone remodelling is a continuous process requiring specific cues for optimal bone growth and implant fixation. In addition, the prevention of biofilm formation on surgical implants is a major challenge. We have identified nanopatterns on Ti surfaces that would be optimal for both bone remodelling and for reducing risk of bacterial infection. We used primary human osteoblast/osteoclast co-cultures and seeded them on flat Ti and three Ti nanosurfaces with increasing degrees of roughness, manufactured using anodisation under alkaline conditions (for 2, 2.5 and 3 hours). Cell growth and behaviour was assessed by scanning electron microscopy (SEM), immunofluorescence microscopy, histochemistry and quantitative RT-PCR methods. Bacterial growth on the nanowire surfaces was also assessed by confocal microscopy and SEM. From the three surfaces tested, the 2 h nanowire surface supported osteoblast and, to a lesser extent, osteoclast growth and differentiation. Bacterial viability was significantly reduced on the 2h surface. Hence the 2 h surface provided optimal bone remodelling conditions while reducing infection risk, making it a favourable candidate for future implant surfaces. This work was funded by EPSRC grant EP/K034898/1.

Introduction: The evolving pattern of bacterial resistance at septic revision surgery to the common antibiotics used during total hip arthroplasty is described.

Methods: A retrospective review of 72 case notes and microbiology data inclusive of bacterial sensitivity profiles was undertaken between January 2002 and April 2007. Data collected was combined with a previous study to demonstrate bacteriology trends over the last thirty years (327 cases). Antibiotic sensitivities to the two common infectious agents, Staphylococcus aureus and coagulase negative staphylococi were formulated into a hypothetical model combined with Gentamycin sensitivity, a constant factor (the sole antibiotic in bone cement), to assess the efficacy of the combination of antibiotics used in primary arthroplasty.

Results: When compared to previous microbiology data percentage isolates of each bacterium were found to be similar, confirming that the infectious agents at septic revision had remained the same, and were the common contaminants at primary surgery. The results also demonstrated an overall trend of increased resistance of the major organisms to the major classes of antibiotics used. Staphylococcus aureus and coagulase negative staphylococci were routinely tested against nine common antibiotics, inclusive of Gentamycin. Critical findings showed that the regimen used in routine primary surgery covers only 67% of staphylococcus infections (cefuroxine and Gentamycin); combinations that showed increased coverage included clindamycin and Gentamycin, and rifampicin plus Gentamycin, providing in excess of 100% coverage, and Erythromycin and Gentamycin, coverage in excess of 80%.

Discussion: Consequently we can recommend from prospective analysis of common infections at septic revision, that the antibiotic regimen at primary surgery is not sufficient to prevent infection (in isolation). Dynamic variations continuously develop in bacteria; genetic make up is regulated to optimise survival, continuously detrimentally affecting the efficacy of antibiotics against the power of super bugs, indicating a pattern in need of continuous monitoring and review.