21 October 2020
CVS Veterinary Specialists, Ben Walton and Professor John Innes, have designed and tested a successful new surgical implant system called the ‘Humeral Intracondylar Repair System’ (HIRS) to treat a condition in dogs called ‘Humeral intracondylar fissure’ (HIF).
A peer-reviewed paper, describing the use of the system on over 40 dogs, has been published in ‘early view’ online by The Journal of Small Animal Practice – A humeral intracondylar repair system for the management of humeral intracondylar fissure and humeral condylar fracture.
The paper reports on the positive clinical outcomes and low complications rates of the new repair system. The system comprises a dual-diameter drill bit that creates a hole for the implant, and a void that is packed with bone allograft (canine demineralised bone matrix) to induce healing. The implant is headless to reduce soft-tissue irritation, is self-compressing to better stabilise the fissure, and is made of titanium alloy for its superior mechanical and biological properties.
Lead author, Ben Walton, orthopaedic Specialist at ChesterGates Veterinary Specialists said: “John and I came up with our concept several years ago and we have worked carefully to refine the design, refine the surgical technique, and test it in clinics with colleagues in practice. The system is already being used successfully by surgeons in UK and some other countries for HIF and humeral condylar fractures, which are a common, related problem in certain breeds such as the Springer Spaniel. We believe that this is a significant step forward in the management of these challenging conditions”.
Professor John Innes, orthopaedic surgeon and Chief Veterinary Officer at CVS Group plc, explained: “I’ve had a 20-year ‘journey’ with HIF. The condition was first recognised in the UK by orthopaedic Specialist, Steve Butterworth, and myself, in the late 1990s and we published a paper on the condition back in in 2001. In the UK, it mainly affects Springer Spaniels, with approximately 15% of Springers having some degree of the pathology.
“Traditional techniques of fixing these non-union fractures with standard bone-screws did not allow for bone grafting, and have been associated with significant complication rates, which can lead to significant morbidity, amputation or even euthanasia. Our paper describes the use of the screw in over 40 dogs with CT-image evidence of some healing in all cases where CT follow-up was available. We report good outcomes and fewer complications compared to traditional techniques used for HIF. I think this system, combined with the canine DBM nanopaste, is a real ‘game changer’ for what has been a very challenging condition to manage.“
The HIRS implant is available from Fusion Implants Ltd but the inventors stress that surgeons need to train in the technique prior to using it. Ben Walton said: “It is important to place any transcondylar implant very precisely, and the HIRS creates a relatively large void to accommodate the bone graft, so it is critical to drill the hole along exactly the right axis. With Fusion Implants, we have developed training opportunities for interested surgeons. Fusion Implants can also supply custom-made, 3D-printed drill guides, which are designed from the dog’s CT scan and will assist greatly with precise drilling. Of course, like any surgery, the skill, training and diligence of the surgeon will also play a critical role, but we have tried to make the surgery as repeatable as we can to ensure good clinical outcomes and lower risks for as many patients as possible.”