Fractures are never identical; each fracture, patient and owner brings its own set of factors to the operating room table. This lecture will present a few of the lessons learned over a decade of practice. A few of these are presented below.
Preoperative imaging is essential for appropriate fracture planning. Radiographs with a calibration bar or ball, as well as CT imaging, can be used to measure bone segments and make preoperative implant choices. Three-dimensional reconstructions of the CT scan can assist the surgeon in preparing for fracture reduction and treatment. In highly comminuted bones, imaging the contralateral bone can give important length and contouring information.
Fractures that are severely contracted can slowly be brought to length using a variety of techniques. It is important that stretching the soft tissues is done gradually. Hanging the limb for the duration of the surgical prep creates tension and can help relax and stretch musculature. The administration of muscle relaxants, if the animal can be ventilated, can also be of assistance.
Both comminuted and simple fractures can be difficult to maintain in alignment during plate application. The placement of a temporary or permanent IM pin assists in bringing the fracture to length and allowing rotational adjustments of the proximal and distal segments prior to plate contouring and application. In the humerus and femur, the pin can easily be placed retrograde, but in the tibia, normograde placement is recommended to minimize trauma to the intraarticular structures of the stifle. Regardless, in order to maximize the distraction of the IM pin without penetration of the distal cortex, the trochar tip should be cut off so the tip is blunt. This is usually performed as the pin is being advanced distally and the tip has just traversed the fracture site. After cutting off the trochar tip, the pin is withdrawn into the medullary cavity, the fracture is reduced, and the pin is advanced by hand. Distraction at the fracture site is easily seen. The pin will maintain length for plate contouring and application, and depending on the fracture configuration and pin placement, may also assist in maintaining rotation. Care must be taken not to allow varus or valgus angulation or underreduction. Following plate application, the pin may be removed or left in place to decrease the load on the plate.
Kirschner wires and small Steinman pins can be particularly useful when reconstructing comminuted articular fractures. Small fragments are pinned to larger ones until a fracture is created that can be rigidly neutralized with plates or screws. K-wires and cannulated drill bits are also useful when narrow safe corridors exist for accurate screw placement (such as in a toy breed humeral condylar fracture). Intraoperative radiographs or fluoroscopy are a great help when working with intraarticular fractures and implants must not be positioned in the joint. Appropriate planning in regards to patient positioning and towel clamp placement is important for the use of intraoperative radiographs. These can avoid the need to return back to the surgical suite after postoperative radiographs.
Appropriate bone-holding forceps are required for efficient fracture repair. Care must be used with the use of these to avoid propagation of fractures lines or compression of immature bone. In oblique fractures of both long bones and flat bones, AO reduction forceps can be used to assist in reduction, the forceps are placed across the fracture angled greater than perpendicular to the fracture line. As the forceps are compressed, the fracture is 'walked' to length and reduction is achieved.
Contouring plates can be tricky, and repeated changes can cycle the plate prematurely. Titanium and stainless steel handle very differently, and different plate types within these metals also require different methods of contouring. For most plates, specific benders and torque application devices can be purchased. The key is to know the plate and to 'sneak up' on the contouring needed. Overcontouring on one end will always result in worsening on the other end. I prefer to work from one end of the bone to the other; generally, but not always, performing the trickiest part (usually distal) last. The advent of locking plates has greatly increased the accuracy maintained during fracture reduction, as perfect contouring is not required. It is important to note, however, that anatomic reconstruction is not always needed and biologic fixation may result in faster healing times.
It is important to note that alternative plans should always be in mind if 'Plan A' does not work out. Ready access to surgical approach books and an extra set of trained hands can come in handy in unfamiliar fracture locations and configurations.