Techinque and Results of CT Guided Repair of Fractures Within the Hoof Capsule

Internal fixation of equine fractures has advanced over the last few decades primarily because of the improving expertise of practicing surgeons and correct application of implants according to proven mechanical principles. The unfortunate reality of fracture repair in horses, however, is that failures still occur commonly because of infection, delayed union and implant failure. Delayed union in species other than the horse is a lesser issue because the consequences of severe lameness and overload of the contralateral limb are less and the expectations for return to function are usually lower. In horses, we still generally recognize that immediate comfort (i.e. stability) is an important element of successful fracture repair and that delayed union is a major complication because of implant failure and contralateral limb problems. Equine surgeons have naturally tended towards aggressive open fracture repairs in order to minimize mechanical “errors” that might reduce stability. Arthroscopy and fluoroscopy/intraoperative digital radiography are already routine adjuncts to many internal fixation procedures but intraoperative CT has enormous potential to minimize the errors that are inherently more likely with minimally invasive techniques.

CT is especially valuable in complex fractures that are difficult to “figure out” from standard films (e.g. comminuted P1), fractures that do not allow adequate fluoroscopic projections that can assure accurate screw placement (e.g. tarsal slab fractures) and bones with a complete lack of direct exposure (P3 and navicular).

Our most highly specific experiences with CT guided fixations are probably within the hoof but the same principles apply when using the CT for intraoperative guidance in other types of fractures or arthrodeses. Use a skin marker to help define the intended site of implant insertion. Use a skin marker on the extended line for the drill bit. Take post- insertion CT to triple check placement.  [...]