Proximal interphalangeal joint arthrodesis in 34 horses using two parallel 5.5-mm cortical bone screws.

OBJECTIVE: To report clinical experience with arthrodesis of the proximal interphalangeal joint in horses using two parallel 5.5-mm cortical bone screws placed in lag fashion. STUDY DESIGN: Retrospective, clinical study. ANIMALS: Thirty-four horses, aged 1 to 19 years. METHODS: Medical records for all horses admitted (1991-1997) for pastern arthrodesis using two 5.5-mm ASIF cortical bone screws, in parallel orientation, and placed in lag fashion by use of a combined aiming device to facilitate accuracy were reviewed. Signalment, lameness diagnosis, duration of lameness, limb(s) involved, and outcome were recorded. Criteria for successful outcome were determined as return to previous level of function or future intended athletic use. RESULTS: Thirty-nine proximal interphalangeal joint arthrodeses were performed on 34 horses. One horse was euthanatized in the recovery room and was excluded from data analysis. Successful outcome occurred in 85% of frontlimbs and 89% of hindlimbs. Failure occurred in 5 joints; 1 horse had lameness directly associated with surgery, whereas 4 horses had unrelated lameness. CONCLUSION AND CLINICAL RELEVANCE: Age, breed, and initial disease did not affect outcome. Arthrodesis of the proximal interphalangeal joint by use of two 5.5-mm ASIF cortical bone screws, in parallel orientation, placed in lag fashion by use of a combined aiming device, resulted in sound use of the limb in >85% of the joints with shortened postoperative coaptation.

Outcome of limb amputations in wapiti: 13 cases (1995-2001).

The object of this investigation was to determine the outcome of limb amputation in wapiti. Medical records of 13 wapiti that underwent limb amputation were reviewed to determine age, weight, sex, injury preceding amputation, limb amputated, amputation location, length of hospital stay, complications, and outcome. Ages ranged from 3 months to 8 years and weights from 70 kg to 280 kg. All animals were female. Eleven animals sustained catastrophic long bone fractures prior to amputation. Five animals had front limb amputations and 8 had hind limb amputations. Of these animals, 1 with a front limb amputaiton and 5 with hind limb amputations survived. Postsurgical inability to stand is associated with hospitalization of > 1 day. Of the 13 wapiti reviewed, 5 with hind limb amputations have produced and reared offspring. Hind limb amputation can be considered a viable alternative to euthanasia when catastrophic orthopedic injuries occur in female wapiti.

Persistent right aortic arch in a yearling horse.

A 14-month-old filly with chronic pharyngitis was diagnosed with incomplete esophageal constriction and megaesophagus due to a persistent right aortic arch. This report is unusual because clinical signs of respiratory dysfunction secondary to chronic regurgitation occurred prior to the recognition of dysphagia.

Repair of complete dorsal fracture of the proximal phalanx in two horses.

Simple complete dorsal fractures of the proximal phalanx were repaired in 2 mature pleasure horses with cortical bone screws placed in lag fashion. Healing occurred within 12 weeks and both horses returned to their previous performance level of light pleasure riding within 6 months of injury.

Repair of a deep digital tendon deficit in a horse using a polypropylene implant.

A yearling horse was treated for a chronic wound with a 4 cm deficit in the deep digital tendon. The gap in the tendon was bridged with paired polypropylene braided implants designed for use as a ligament augmentation device. Uncomplicated healing and return to function occurred.

Lag screw fixation of an extensor process fracture in a foal with flexural deformity.

A 4-month-old colt with stage I flexural deformity of the distal interphalangeal joint was diagnosed as having a type IV nondisplaced fracture of the extensor process of the 3rd phalanx. An inferior check ligament desmotomy and internal fixation of the fracture were performed. Favorable long-term results for internal fixation of extensor process fractures are presented.

Fixation of femoral capital physeal fractures with 7.0 mm cannulated screws in five bulls.

Salter-Harris type I fractures of the femoral capital physis were repaired in five Holstein bulls with three 7.0 mm cannulated screws placed in lag fashion. Radiographically at months 7 to 10, the fractures were healed and there was periarticular bone production on the femoral necks and the dorsal acetabular rims. Four bulls had normal gaits, and one bull had muscle atrophy and barely detectable lameness.

Pulsed radio frequency therapy of experimentally induced arthritis in ponies.

The effect of pulsed radio frequency therapy (PRFT) was evaluated on seven ponies with no arthritis and in 28 ponies in which arthritis was created using intra-articular amphotericin B to induce synovitis in the right middle carpal joint. The ponies were divided into five treatment and two control groups. Two levels of arthritis were created and two dosage levels of PRFT were evaluated. The effect of PRFT on arthritic and nonarthritic joints was measured by comparing synovial fluid parameters, the degree and duration of lameness, the range of carpal motion, and carpus circumference, for treated and untreated groups. Lesions seen radiographically, at gross pathology, and by histopathology were also compared between the treated and control groups. In the ponies with a mild form of induced arthritis, PRFT significantly (p less than 0.05) reduced the severity and duration of lameness, swelling of the carpus, and the severity of gross pathological and radiographic changes. In these ponies the synovial acid phosphatase levels were lower, the mucin clot quality was superior, and the synovial protein levels were lower for the ponies receiving PRFT as compared to the arthritic ponies receiving no treatment. A dose response effect was evident. In ponies with a slightly more severe form of arthritis, PRFT was evaluated at one dosage level. The treated ponies were significantly improved over the untreated ponies with respect to carpal range of motion, degree of lameness, carpus swelling, and radiographic lesions. No deleterious effects were noted when normal, PRFT treated, middle carpal joints were compared to contralateral untreated, normal joints. It was concluded that significant beneficial effects resulted when affected ponies were treated with PRFT.

Intra-articular replacement of bovine cranial cruciate ligaments with an autogenous fascial graft.

Transected cranial cruciate ligaments in nine Holstein heifers were replaced with an autograft harvested from fascia on the medial surface of the gluteobiceps muscle and a connected segment of the lateral patellar ligament. There was minimal lameness at month 1, and all animals were sound by month 2. There was no evidence of degenerative joint disease in any stifles examined at necropsy on days 90, 120, or 365. Augmented healing of the severed cranial cruciate ligaments occurred in several animals. The mean failure strength of the cranial cruciate ligament replacements was 29.7% of the failure strength of the contralateral normal cranial cruciate ligament in four heifers. The technique was successful in eight of 13 bulls and cows with ruptured cranial cruciate ligaments. Animals treated successfully had significantly lower body weights than those with unsuccessful outcomes.

A surgical approach to the ramus of the mandible in cattle and horses. Case reports of a bull and a horse.

A surgical approach to the ramus of the mandible was developed. Subperiosteal elevation of the masseter muscle from the ramus allowed reduction and plate fixation of ramus fractures in a bull and a horse. Results of follow-up examinations, 2 years after surgery, showed excellent functional and cosmetic results.

Dentistry's future at the University of Southern California.

Participation in the National Dental Education Program has been a most important activity. It has had great impact on the future well-being of the USC School of Dentistry. Success in Phases 1 and 2 was, of course, important. However, the involvement in training sessions, where ideas were exchanged and new skills learned, was probably of more importance. Communication with university officials suddenly became easier--we now spoke a common language and could respond more effectively than before. While the outcomes will be important in changing the school's course, the process leading to the outcomes will also produce significant change. Planning took on new meaning at USC. We are now able to respond to opportunities that come knocking at our door. We are able to see relationships previously invisible. We are beginning to recognize that what each does, in whatever activity, matters a great deal. We--faculty, students, staff, and alumni--are interdependent to a larger degree than previously thought. Challenging years are in store for the USC School of Dentistry. Much needs to be done to ensure dentistry's future at USC into the 21st century. The school is located at the right place at the right time. The external environment beckons for increased involvement by the School of Dentistry. If the school can address the challenges posed by the changed internal environment, it is well positioned to become the most important resource in dental education, in dental care, and in dental information in the Southwest.

Dental school finances: current status.

Total expenditures and revenues of 58 US dental school were derived from reports of the ADA Division of Educational Measurements. These financial data were studied by type of dental school (public, state-related private, and private) and by expenditure/revenue categories. Dental schools showed little diversity in expenditures: most were directed toward instruction; few were directed toward research or continuing education. Several distinctive patterns among the three types of dental schools in revenues were observed. Two configurations emerged: public and state-related private dental schools receive more than 75% of their revenues from government and tuition, and private dental schools, more than 50%.

The effect of racetrack design on gait symmetry of the pacer.

A survey of a western Canadian racetrack determined the superelevation and transition curves to be less than the cited design standards. High-speed cinematography was used to film seven Standardbred pacers as they proceeded around one curve of the track at racing speed and for each horse 19 temporal stride parameters were obtained from these films using a film analyzer system. Average velocities were calculated and the mean stride length was found to vary from 5.08 m to 5.77 m. In all frames analyzed the hind foot was observed to contact the track surface prior to the ipsilateral forefoot and all horses displayed significant (p less than 0.05) contralateral asymmetry of some temporal stride parameters. Fifteen temporal stride parameters were significantly different (p less than 0.05) when compared between horses but only three temporal stride parameters were significantly different (p less than 0.05) when their values were compared between segments of the curved portions of the track. It is suggested that temporal gait asymmetry should not be used to judge the standards of racetrack design.

Guidelines for the future of equine locomotion research.

This paper describes the major areas that require investigation in equine locomotion and outlines a plan for such research in both the Thoroughbred and Standardbred. Fifteen topics for future investigation have been selected and given an order of priority. These topics deal with characteristics of normal locomotion, factors which influence locomotion, the epidemiology and economics of lameness and the clinical identification of lameness.