Chapter 7 - Veterinary Instrumentation

www.vetinst.comTRAUMA IMPLANTS & INSTRUMENTS 7Hybrid Intertarsal Arthrodesis PlatesHYBRID INTERTARSAL ARTHRODESIS PLATEWhere the tibio-tarsal joint can be preserved, intertarsal arthrodesis ispreferred to pantarsal arthrodesis, allowing a near normal range of motionto be maintained.Hybrid Plates are very helpful in permitting larger screws to be used in thecalcaneous and smaller screws to be used in the finer metatarsals. Acentral round hole is to engage the fourth metatastal bone. Thehybridisation also allows the Plates to become much thinner distallyallowing for easier closure of soft tissues. The 2.7/2.7 Plate will also accept2.4mm screws distally.Many of the early Intertarsal Plates were modified pancarpal Plates withadjustments made to squeeze them onto the lateral aspect of the limb.As Geoff Robins has suggested, many of these result in holes spacing thatis sub-optimal, with the biggest criticism being that the spacing of the T4and proximal metatarsal holes is too great. With Geoff’s help, we havedeveloped our extended range of Intertarsal Plate for 2013.152920 has been modified to mirror the optimal spacing of our all newsizes. The proximal hole spacing has also been optimised, so that theseplates adequately span the cuboidal bones in the vast majority of patients.152924 Hybrid Intertarsal Arthrodesis Plate 1.5/2.0mm * £105.00152923 Hybrid Intertarsal Arthrodesis Plate 2.0/2.0mm * £105.00152920 Hybrid Intertarsal Arthrodesis Plate 2.0/2.7mm £105.00152922 Hybrid Intertarsal Arthrodesis Plate 2.7/2.7mm * £105.00152921 Hybrid Intertarsal Arthrodesis Plate 2.7/3.5mm £105.00152925 Hybrid Intertarsal Arthrodesis Plate 2.7/3.5mm * £105.00Plate profile on page 396.* Available June 2013Pantarsal Arthrodesis by Cranial Hybrid PlateThe concept of a cranial plate is not new. Contoured DCPs have beenused with success for pantarsal arthrodesis. However, there is afundamental problem with the use of DCPs. The loading takes placeacross the weakest plane of the plate on the compression side of the jointresulting in a relatively weak construct which leads to cycling and platefailure usually at the hole closest to the bend. In addition use of the samediameter screw in both metatarsals and the tibia always results in amismatch. A large screw in the distal metatarsal makes the metatarsalinvolved very vulnerable to fracture.Although requiring more initial dissection than the medial approach, thecranial plate makes alignment easier and does not involve screwingmetatarsals to each other. Stability across the talocrural joint is achievedby a screw which passes through the plate and crosses the joint into thecalcaneus.Noel Fitzpatrick and VI have revisted the cranial plate and have developeda range plates which allow the surgeon to benefit from the advantages ofcranial plating while minimising the risks of failure. The Plates are hybrid innature and taper distally to reduce the stress riser at the end of the plate.The vulnerable area on either side of the bend is substantially thicker andstronger than the plate proximally and distally to reduce stress at the joint.For maximum stability it is essential that a screw is placed across thetalocrural joint. To facilitate this the holes on either side of the bend areextended into slots to increase the range of screw angles possible.An aiming device is available to assist the surgeon in placing these vitalscrews.The shape of the cranial plate lends itself to being placed by minimallyinvasive plate osteosynthesis (MIPO) to preserve as much soft tissue aspossibleFeline Cranial Pantarsal Arthrodesis PlateCase: Noel FitzpatrickFeline Cranial PantarsalArthrodesis MIPODeveloped incollaboration with NoelFitzpatrick we offer adedicated cranial platewith holes placed inexactly the correctpositions and machinedto allow appropriatescrew angulation tosecure the talus. ThePlate is a hybrid havingsmaller holes distally ina range of sizes. ThePlate tapers distally toreduce the stress risereffect on themetatarsals.IMPROVEDDESIGNCase: Noel FitzpatrickFELINE CRANIAL PANTARSAL PLATE152941 Feline Cranial Pantarsal Arthrodesis Plate 2.0/2.0mmCalcaneal Holes accept 2.0 or 2.4mm Screws £115.00203