Serial section electron microscopy (SSEM) was initially developed to map the neural connections in the brain. SSEM eventually led to the term ‘Connectomics’ to be coined to describe process of following a cell or structure through a volume of tissue. This permits the true three-dimensionality to be appreciated and relationships between cells and structures. The purpose of this study was to utilize this methodology to interrogate S. aureus infected bone.

Bone samples were harvested from mice tibia infected with S. aureus and were fixed, decalcified, and osmicated. The samples were paraffin embedded and 5-micron sections were cut to identify regions of bacterial invasion into the osteocyte-lacuna-canalicular-network (OLCN). This area was cut from the paraffin block, deparaffinized, post-fixed and reprocessed into epoxy resin. Serial sections were cut at 60nm and collected onto Kapton tape utilizing the Automated Tape-collecting Ultramicrotome (ATUMtome) system. Samples were mounted onto 4” silicon wafers and post-stained with 2% uranyl acetate followed by 0.3% lead citrate and carbon coated. A ZEISS GeminiSEM 450 scanning electron microscope fitted with an electron backscatter diffusion detector was used to image the sections. The image stack was aligned and segmented using the open-source software, VASTlite.

264 serial sections were imaged, representing approximately 40 × 45 × 15-micron (x, y, z) volume of tissue. 70% of the canaliculi demonstrated infiltration by S. aureus.

This study demonstrates that SSEM can be applied to the skeletal system and provide a new solution to investigate the OLCN system. It is feasible that this methodology could be implemented to investigate why some canaliculi are resistant to colonization and potentially opens up a new direction for the prevention of chronic osteomyelitis. In order to make this a realistic target, automated segmentation methodologies utilizing machine learning must be developed and applied to the bone tissue datasets.

Aims

The BOA/BAPRAS guidelines for the management of open tibial fractures (2009) recommend early senior combined orthoplastics input and appropriate facilities to manage a high caseload. St Georges Hospital is one of four London Trauma Centres fulfilling these criteria. Our aim is to determine whether becoming a trauma centre has affected the management of patients with open tibial fractures.

Purpose: The authors would like to report the outcome following evaluation of surgical treatment for acetabular fractures with more than 10 years follow-up.

Materials and methods: 133 consecutive patients were evaluated with 10–16 years post surgery follow-up (mean 12 years). Mean age was 34 years (17 to 70 range) and male: female were 2:1. 90% of our cases were tertiary referrals. The follow-up assessments included AP pelvis and Judet view radiographs and clinical evaluation was performed with the Harris hip score, Modified Merle d’Aubigne score and the SF 36v2 health survey.

Results: Fracture reduction was anatomical in 69% of the patients and in 31% it was non-anatomical. The reduction of the acetabular fractures was considered anatomical when all five lines on post-operative radiographs were corrected and the hip was congruent. Among our patients, 19% had excellent clinical results according to the modified Merle d’Aubigne Score and 58% according to the Harris Hip Score. A poor clinical outcome was identified in 18% of our patients according to the modified Merle d’Aubigne Score and 23% according to the Harris Hip Score. Radiographic evidence of osteoarthritis was in 35,8% of our patients (all grades of arthritis). 6 of our patients had neurological complications (sciatic nerve palsy) (3 pre-operatively, 2 post- operatively and in one patient there was a delayed sciatic nerve palsy secondary to haematoma). In 7 patients (8.6%) there was heterotopic ossification but in only three that was clinically a problem. Two patients developed intraoperatively pulmonary embolism. We had no post-operative deep vein thrombosis or pulmonary embolism.

Conclusions: Our results compare favourably with those of previous published studies with shorter follow-up period. Anatomical fracture reduction is mandatory and improves the clinical outcome. Infection and avascular necrosis are associated with poor clinical outcome. Early surgical intervention for displaced acetabular fractures can improve the final outcome.