CT Guided Repair of Fractures of the Proximal Phalanx and Metacarpal/Metatarsal Condyles in TB Racehorses

Since January 2014 at Newmarket Equine Hospital, all Thoroughbred racehorses undergoing surgical repair of a parasagittal, frontal or comminuted fracture of the proximal phalanx, and parasagittal or spiral fracture of the metacarpal or metatarsal condyles, underwent pre-operative Computed Tomographic (CT) examination. CT was performed under general anaesthesia immediately prior to surgery using a portable 8 slice small-bore scanner (CereTomR). Images were assessed patient side by the operating surgeon and fractures mapped. The diagnostic information obtained was used to guide surgical planning. In select cases, further CT scans were obtained intra-operatively to assist implant placement.

Image acquisition typically took less than 15 minutes, including positioning of the patient, obtaining a scout and the final scan sequence. Pre-operative imaging only was performed in 99 cases. In three horses further, scans were acquired intra-operatively to guide placement of implants when repairing short incomplete parasagittal fractures of the proximal phalanx.

When compared to radiography, CT enabled mapping of fracture configuration with improved accuracy, and as a consequence enhancing surgical planning. This was particularly apparent with spiral fracture configurations. Three-dimensional reconstructions enabled better visualization of fracture configuration. Measurements obtained at proposed sites of implant placement from multi-planar reconstruction were more accurate than those obtained radiographically. The difference was most apparent when implants were positioned away from the widest point of the bone, for example when repairing unicortical short incomplete parasagittal fractures of the proximal phalanx.  [...]