A tapered-sleeve transcortical pin external skeletal fixation device for use in horses: development, application, and experience.

This research developed, applied and examined the results of a novel tapered-sleeve transcortical pin external skeletal fixation device (TSP ESFD) designed for equine fractures. The study found the device offered a promising treatment alternative for severe injuries on the lower part of a horse’s limb, potentially reducing the risk of bone fracture at the pin interface.

Development and Application of TSP ESFD

• The research focused on creating a new type of external skeletal fixation device, specifically the tapered-sleeve transcortical pin external skeletal fixation device (TSP ESFD). This device is intended to be used for treating fractures of the distal aspect of a horse’s limb, essentially the lower part of the limb.
• The researchers tested this device on third metacarpal bones, known as MC3, from adult horse cadavers and also administered the device on seven separate live horses with severely fragmented or ‘comminuted’ fractures in their proximal phalanx (P1) or second phalanx.
• Alongside the application tests, mechanical testing methods were employed to see how the device could be best attached to the sidebars and to optimise the diameter of the pins used in the device. The final device used pins with a diameter of 7.94mm.

Case Study Outcomes and Findings

• Findings from the case studies conducted were then compared with existing solutions to assess the device’s effectiveness. The survival rate for the horses treated with the new device was found to be 71%.
• However, one of the horses that had been treated for P1 fracture and had an infected fracture site, ended up fracturing their MC3 at the distal pin hole while undergoing treatment with the TSP ESFD. Meanwhile, there was one case of euthanasia in a mare suffering from contralateral laminitis.
• Out of the seven horses treated, three had open fractures.

Conclusions and Further Implications

• The study finds that external skeletal fixation continues to be a relevant treatment method for severe injuries of a horse’s lower limb. The research suggests that the TSP ESFD device should improve on existing treatment success rates by helping to lower the risks of bone fractures occurring at the pin interface.
• The design improvements incorporated into the TSP ESFD could potentially increase treatment success rates. Nevertheless, the research also highlights the need to continue investigation into methods for reducing complications associated with bone fractures and pin attachments.