High energy chest trauma resulting in flail chest injury is associated with increased rates of patient morbidity. Operative fixation of acute rib fractures is thought to reduce morbidity by reducing pain and improving chest mechanics enabling earlier ventilator weaning.

A variety of operative techniques have been described and we report on our unit's experience of acute rib fracture fixation. Over 18 months, 10 patients have undergone acute rib fracture fixation. Outcome measures included; patient demographics, time ventilated pre-operatively, time ventilated post-operatively and time spent on ITU/HDU post operatively.

The mean time from presentation to surgery was 5 days (range 2–12 days). The mean time ventilated post operatively was 2 days (range 1–4 days) and the mean number of days spent on ITU/HDU post-operatively was 6 days (range 2–11 days).

Our results appear positive in terms of time spent ventilated post-operatively but no conclusion can be drawn as we have no comparable non-operative group. We have however shown, that rib fracture fixation can be carried out successfully and safely in a trauma centre. Further evidence on rib fracture fixation is required from a large, multi-centre randomised controlled trial.

Purpose: To evaluate the appropriateness of posterior blade plate ankle arthrodesis as a salvage procedure, in a complex subgroup of ankle trauma patients.

Methods: We retrospectively identified all patients who underwent an ankle arthrodesis from our prospectively collected trauma database at Vancouver General hospital from 1997 to 2005. We then extracted those who had blade plate arthrodesis via the posterior approach for previous failed fracture fixation or failed previous fusion. Demographics, pre arthrodesis diagnosis, previous surgeries, deformity and complications were recorded. Clinical examination was based on outpatient evaluation and physical evaluation. This was supplemented with radiological follow up to confirm union and outcome scoring using the AOFAS and SF36 systems.

Results: Sixteen patients were identified from the trauma database who had undergone posterior blade plate ankle arthrodesis. Of these thirteen were available for follow up. There average age was 47 years (range 23–63 years). The male to female ratio was 3:1. Three cases were for failed previous ankle fusion by other means. Of the remaining ten patients with post traumatic osteoarthritis, seven had previous pilon fractures, two talar fractures and one fracture dislocated ankle. All cases went onto bony union. Patient satisfaction was good although functional outcome scoring was not normal

Conclusion: We have found this procedure to have several excellent benefits. It allows the surgeon to operate through virgin skin, reducing potential wound complications, and achieve good soft tissue coverage. The blade plate allows reconstitution of a normal plantar grade ankle and distal tibial orientation, when secured appropriately to bone. Excellent compression and union can be achieved with the AO compression device, but it’s important to have a second screw in the talus to prevent blade pull out. The procedure has good satisfaction among patients following previous failed surgery, as a salvage procedure.

Background: The next generation of biomaterial surfaces for use in orthopaedic surgery will be functionalised to promote osteogenesis. This will be achieved in part by the stable addition of functional bioactive molecules onto the biomaterial surface. Heparan sulphate is a complex glycosaminoglycan (GAG) that displays cell and tissue specific differences in size and levels of sulphation. It is this heterogeneity that underlies the numerous biological roles of heparan sulphate, including binding of growth factors and proteases. Findings by others have shown that the addition of heparan sulphate proteoglycans stimulate osteoblast differentiation in vitro.

Aims: To characterise heparan sulphate structures that support and enhance osteogenesis and have the potential for tissue engineering.

Experiment 1. In order to further investigate the role of heparan-sulphate proteoglycans (HSPGs) in osteogenesis we supplemented cultures of differentiating rat osteo-blasts with sodium chlorate (an inhibitor of the enzyme that sulphates GAG chains) or 4-methylumbelliferyl-b-D-xyloside, BDX (an artificial acceptor of GAG chain synthesis). Interestingly the addition of chlorate to our culture system significantly stimulated alkaline phosphatase levels and increased the area of Von Kossa stained bone-like nodules. Whereas, when BDX was added to differentiating rat osteoblasts there was no increase in alkaline phosphatase activity or nodule area.

Experiment 2. Further characterisation of the HSPGs in chlorate treated osteoblasts showed that whilst they were less sulphated than untreated cells (as shown by low salt elution from an anion exchange chromatography column) they were much more abundant. These observations led us to hypothesise that less sulphated forms of heparan sulphate may well stimulate osteo-blast differentiation.

Experiment 3. To test this hypothesis we took the fully sulphated form of heparan sulphate, heparin and selectively desulphated it using DMSO/methanol (9:1) at 97°C and specifically N-resulphated or N-acetylated. These partially desulphated heparins were then added to osteoblasts cultured under osteogenic conditions. Quantification of bone nodule formation showed that specifically desulphated heparin significantly increased mineralised areas compared to controls whilst the addition of heparin inhibited osteogenesis. How these modified heparan sulphates exert their effect on bone cells is unknown, but a well characterised role of heparan sulphate is the support of FGF signalling. In preliminary studies we have shown through the activation of p42/44 MAPK and proliferation assays that the modified heparan sulphates are able to support FGF signalling in bone cells.

Experiment 4. Currently were are attaching our desulphated heparin to biomaterial scaffolds and examining osteoblast attachment and migration/ingrowth in cell culture.

Conclusion: We have isolated heparan sulphate chains that demonstrate osteogenic properties and have the potential for enhancing biological interactions of orthopaedic implant materials.