The 2011 National Hip Fracture Database (NHFD) Report has shown our institute has the fewest number of patients meeting the 36-hour target to theatre in the UK (9%) but well above the national average for review by geriatrician (42.5%) at 76%. We believe our timely medical input means patients' are more physiologically normalised prior to surgery. We aimed to review our postoperative results to see if our patients had significantly different morbidity and mortality compared to the rest of the UK.

We reviewed 152 patients between the period September 2009 and September 2010. All of the patients were prospectively identified and their information was added to our hip fracture database. Using the auditing software we reviewed the patients' outcomes and compared them to national averages using figures from the NHFD.

Of the 152 patients identified 13% met the 36-hour target. The average time to theatre for the study group was 89 hours. 83% of the group had a pre-operative assessment by a geriatrician. The primary reason for surgical delay was a lack of space on a theatre list (61.2%) followed by being medical unfit (16.4%). The average length of acute hospital stay was 16.4 days matching the national average while 30 Day mortality at 7.9% was (0.5%) lower than NHFD figures.

We continue to try and improve our time to surgery for hip fracture patients and accept this is mostly related to limited theatre access. Deficient resources due to Northern Ireland's exclusion from the best practice tariff means we are unable to compete with the top performing units in the NHFD. While it makes humanitarian sense to expedite surgery, evidence used to determine the 36-hour target is quoted as “low quality” or “very low quality”. Our data shows no significant difference in outcomes compared to national figures.

Introduction: Osteoblasts precursors reside in the marrow and small numbers circulate in the blood. Our previous work demonstrated an increase in circulating cells following fracture in humans. Skeletal injury is recognised to stimulate a distant osteogenic response.

We hypothesised that in response to fracture, some integral osteoblasts are recruited via the circulation from remote bone marrow sites.

Method: We established a fracture union model in 3-month-old, male, New Zealand White rabbits and reimplanted labelled autologous osteoblast precursors. At date of submission we have 20 rabbits allocated into 4 groups. Three groups had labelled cells re-implanted, whilst the fourth control group did not receive cells. In groups I, II and III the cells were re-implanted into the fracture gap, into the circulation and into a remote bone marrow cavity respectively. There were six animals in groups I and IV, and four in both II and III.

All animals had bone marrow harvested from their right tibia by saline flush. The mononuclear cells were isolated and culture-expanded in osteogenic medium for 3 weeks. Fluorescent reporter molecules were incorporated into the cell membranes, 24 hours prior to re-implantation of the cells into the fracture model. A 3 mm ulnar defect was preformed in all the animals. In groups I–III this was established 48 hours prior to cell re-implantation.

The animals were sacrificed at least 3 weeks after fracture surgery. Representative samples of the fracture callous, lung, liver, spleen and kidney were harvested from all animals and cryo-sectioned. Using confocal microscopy, the labelled cells were expressed as the average in 5 high power fields for each solid tissue. In addition, cyto-spins were made from blood and marrow and the cell number expressed as a percentage of the total cells.

Results: In group I, labelled cells were identified in the fracture callous, establishing their viability in vivo. Following intravenous re-implantation a smaller number of labelled cells were identified in the callous. When the cells were re-implanted into a remote marrow site, the number of cells in the callous was greater than after venous reimplantation, but less numerous than those in group I.

In all sections, these labelled cells appeared on trabecular surfaces in an osteoblastic fashion, but occasionally they were surrounded by osteoid, corresponding to osteocytes.

A small number of labelled cells were found in the blood, bone marrow, lung, liver and spleen of all animals in groups I–III. No labelled cells were identified in the kidney tissue.

Discussion and Conclusions: We have demonstrated that cells from remote sites are integral in fracture healing. Their presence in callous following venous administration supports recruitment via the circulation. This preliminary data is a proof of concept. This is an exciting new phenomenon, which could provide alternatives for harvesting skeletal progenitor cells and for their delivery in the treatment of bony pathology.