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tvpjournal.com | November/December 2015 | ToDay's VeTeriNary PracTice a PracTiTioNer's GuiDe To FracTure MaNaGeMeNT Peer reviewed 35 of the fracture. 3 See Orthopedic Hardware: Linear ESF (page 33) for further details on using linear ESFs. Follow-Up Since constructs can damage, or get caught on, household items, the ESF frame should be bandaged, which requires rechecks every 7 to 10 days to evaluate the frame and change the bandage. In addition, while the implants are in place, during each recheck the skin– pin interface should be monitored and cleaned regularly to prevent superfcial infections or draining tracts. BONE PLATES & SCREWS Bone plating is ideal for preventing many of the potential forces that will be imposed on the fracture, including compression, shearing, rotation, and bending. The plate–bone construct is weakest in regard to bending forces; therefore, the plate is always placed on the tension side of the bone. An IM pin can be combined with a plate to enhance bending strength (Figure 5). 1 Indications Bone plates can be used for almost any fracture type if there is enough bone length proximal and distal to the fracture to allow for placement of 3 screws in each fragment, engaging a minimum of 6 cortices. This general rule can be used to determine the length and type of plate that should be applied in any given situation. Technique Bone plates (see Orthopedic Hardware: Bone Plates & Screws, page 36) can be placed in bridging, buttressing, or compressing fashion, depending on the fracture type. • Bridging and buttressing fashion: Used for fractures that cannot be readily reconstructed or for long bone fractures in which the length of bone must be restored and maintained in the face of comminution and bone loss. • Compressing fashion: Used when the bony column can be reconstructed and the ends of the fracture fragment can be compressed together, which allows the bone to share in load bearing during the healing process. Screws are placed in either neutral or compressing fashion dependent on planned use of the plate. Additionally, independent of use in the plate, screws can be placed in lag fashion to apply compression across a fracture line—a method commonly used with humeral or femoral condylar fractures (Figure 6): • The near (cis) cortex is drilled to the same diameter of the screw threads (glide hole), while the far (trans) cortex is drilled slightly smaller than the core diameter of the screw. Plates: Buttressing Versus Bridging A bone plate used in a buttressing fashion is designed for metaphyseal fractures to prevent collapse of the area adjacent to an articular surface due to compressive forces. A plate used in a bridging fashion (in old terminology used interchangeably with buttressing) is designed to act as an internal splint to maintain the correct length and normal axial alignment when fracture ends cannot be anatomically reconstructed. More simply, this placement bridges the fracture site to hold the bones in reduction and alignment, allowing the bone to heal. FIGURE 6. Craniocaudal radiograph illustrating use of a lag screw for a condylar fracture in the femoral condyle of a cat; note there is also cross pin fxation to address additional comminuted aspects of the fracture. Screws: Neutral Versus Compressing A screw used in a neutral fashion (also known as a plate screw ) is placed in the center of the screw hole only to hold the plate in place. A screw used in a compression fashion allows movement of the bone fragment relative to the plate as it is tightened, leading to compression of the fracture. Screw holes in compression plates have an oval shape (rather than the round shape seen in noncompression plates) that allows the screw to be placed at one end of the oval.