2.8 References
1. Matthews LS, Hirsh C (1972) Temperatures measured in human cortical bone when drilling. J Bone Joint Surg [Am]; 54:297.
2. Perren SM (1976) Force measurements in screw fixation. J Biomech; 9:669–675.
3. Askew MJ, Mow VC (1975) Analysis of the intraosseous stress field due to compression plating. J Biomech; 8:203.
4. Schenk RK (1964) Zur Histologie der primären Knochenheilung. Langenbecks Arch Klin Chir; 308:440.
5. Hayes WC, Perren SM (1972) Plate-bone friction in the compression fixation of fractures. Clin Orthop; 89:236–240.
6. Nunamaker DM, Richardson DW, Butterweck DM (1991) Mechanical and biological effects of plate luting. J Orthop Trauma; 5:138–145.
2.8.1 Online references
See online references on the PEOS internet home page for this chapter: http://www.aopublishing.org/PEOS/02.htm
Gustave E. Fackelman
3.1 The day before surgery
The patient should arrive safely at your facility having been given appropriate first aid and having been carefully transported, the details of which are described elsewhere [1]. The following discussion is intended as a checklist of activities to promote ideal operative conditions and enhance the probability of a satisfactory outcome.
Completeness of biographical data should be carefully checked. The patient's name, age, breed, previous surgical/anesthetic history, known drug sensitivities, the dates of injury and of arrival, along with the owners name, address and telephone number would be the minimum. Gathering this data, as well as recording much of which is described below can be facilitated by the use of an appropriate computerized format such as the AO Equine Fracture Documentation System [2].
The owner should be made aware of the alternatives to surgery, the risks involved in any operative procedure, and any dangers that are specific to the intended surgery in this particular horse. A clear description of these risks should be part of a written document that details the operation and the recommended aftercare. This document is countersigned by the owner as having been read and understood. On the same page, the owner is provided with an enumeration of the costs involved and an estimated value of the animal concerned. (This latter value may be left to the owner to fill in.) This information is important to patient care and client relations and also touches upon the medicolegal aspects of patient care, described at length in a recent text [3].
Perform a complete physical examination including a hemogram.
Assess lameness and associated lesions. (See Movie: Evaluation of the Equine Musculoskeletal System).
Start gathering data by using the AO Equine Fracture Documentation System.
Make the owner aware of the alternatives to surgery and have your description countersigned.
A complete physical examination and hemogram are performed. While focused on the musculoskeletal system, including potentially predisposing conformational defects, care is taken to evaluate the animal as a whole. Assessment of lameness and any associated lesions should follow a systematic approach [4] with which the clinician has become comfortable. In the so-called exercise induced fractures [5], particular attention is paid to the possibility of the lesions being bilateral. The pain on one side is usually greater than on the other, and masks the existence of the second fracture. The findings of the examination are carefully documented, and communicated to the owner and any interested colleagues in practice. The initial (referral) set of radiographs is reviewed and augmented when necessary with additional views. From these films, a preoperative plan is diagrammed indicating the location and size of the implants to be used in the surgical repair (Fig. S3A). This plan is initially used to serve as a check on the availability of implants in the size(s) indicated, and the appropriate instrumentation for their insertion, and later to guide the surgeon during the actual operation. Recently a Large Animal Preoperative Planner has been introduced.
Fig. S3A
The area surrounding the surgical site is clipped with a fine blade (#40). For fractures of the limbs distal to the carpus or the hock, this is carried out circumferentially to facilitate draping in a subsequent step. The entire animal is bathed to remove dirt, sweat, and detritus from its body and limbs (Fig. S3B), and the operative site is scrubbed with a soap containing tamed iodine. A sterile dressing is used to cover the site, and this is held in place with a light bandage (Fig. S3C).
Fig. S3B
Fig. S3C
Perioperative antibiosis is warranted even in elective surgeries [6]. When truly prophylactic, it is brief in duration, extending roughly from the day before surgery to the day after [7]. The nature of this therapy will be dictated by the condition of the surgical site [8], concerns about anesthetic interactions [9], the presence of infection at a distant locus [10], the identification of nosocomial organisms, or certain details of the procedure itself [11]. As a rule, the treatment is timed so that an effective level of drug is present at the time of surgery. Broad-spectrum antibiosis consisting, for instance, of a penicillin and an aminoglycoside is