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Biomedical subjects

T A Turner

Publications and source records attributed to T A Turner.

At least 19 recordsLinked to original sources

Ultrasonographic abnormalities detected in the sacroiliac area in twenty cases of upper hindlimb lameness.

REASONS FOR PERFORMING STUDY: The pelvis is covered with extensive musculature and often presents a challenge in diagnostic imaging. Ultrasonography provides diagnostic information about soft tissue, articular cartilage and bone surfaces, although little information exists about the normal ultrasonographic appearance of the equine sacroiliac region. OBJECTIVES: To determine the clinical applicability of ultrasonographic examination in horses with sacroiliac pain. METHODS: Horses presented to the University of Minnesota Veterinary Teaching Hospital for hindlimb lameness were evaluated and lower limb lameness was ruled out with examination and local anaesthesia. Twenty cases were diagnosed with sacroiliac pain, characterised by response to palpation over the tuber sacrale. Seven of the 20 had visible asymmetry of the tuber sacrale. Ultrasonography was performed percutaneously and per rectum. Structures imaged were measured and compared to normal reference measurements. Other methods used to confirm diagnoses included thermography, scintigraphy and radiology. RESULTS: All 20 cases with sacroiliac pain showed ultrasonographic abnormalities of the sacroiliac area. Abnormalities were detected in the dorsal sacroiliac ligaments. Ligament size was significantly different from the normal ranges (P < 0.01). Malalignment of the sacroiliac area and sacral fractures were also imaged. CONCLUSIONS: Ultrasonography of the sacroiliac region aided diagnosis of ligament damage and displacement of bone surfaces; and may aid in monitoring the progression of healing. POTENTIAL RELEVANCE: Diagnostic ultrasound is readily available to most practitioners. Therefore the findings of this study show that diagnosis of sacroiliac injuries is possible in the field.

Animals↗

Diagnostic thermography.

Thermography is a practical aid in the clinical evaluation of the equine patient. It is particularly germane to the evaluation of lameness. This modality specifically increases the accuracy of diagnosis. Thermography is the pictorial representation of skin temperature. The technique involves the detection of infrared radiation, which can be directly correlated to blood flow. To be accurate, thermography must be performed in a controlled area free of drafts. The area should be protected from sunlight to avoid erroneous heating of the skin, and the horse's hair length should be uniform. Thermography detects heat before it is perceptible during routine physical examination and thus is useful for the early detection of laminitis, stress fractures, and tendinitis. It offers a noninvasive means of evaluating the blood supply to an injured region and represents one of the only reliable noninvasive means to evaluate blood flow to the foot of the horse. Thermography is also useful for the early identification of stress injuries to the contralateral limb of convalescing orthopedic patients. Thermography is an excellent adjunct to clinical examination as well as being complementary to other imaging techniques such as radiology, ultrasonography, and scintigraphy.

Animals↗

Detailed ultrasonographic mapping of the pelvis in clinically normal horses and ponies.

OBJECTIVE: To map the equine pelvis using ultrasonography, validated by use of computed tomography (CT), magnetic resonance imaging (MRI), and measurements of frozen cadaver slices. ANIMALS: 6 ponies and 6 horses. PROCEDURE: Ultrasonographic examination of the pelvis was performed on 6 clinically normal ponies. Measurements were obtained for imaged structures. Computed tomography, MRI, and measurements of frozen sections were performed after death and used to verify measurements. Linear regression determined the degree of correlation between measurements obtained ultrasonographically and the other modalities. Six clinically normal horses were then examined by use of ultrasonography. For each structure measured mean, SD, and range were calculated. RESULTS: Data obtained from ponies revealed high correlations between ultrasonographic findings and those of CT, MRI, and frozen section measurements (r2 = 0.97, r2 = 0.99, and r2 = 0.99, respectively). Differences between structures measured on each side of the pelvis were not significant. Variation in size of structures was not associated with weight of horses. A correlation was not found between weight of horses and ponies and size of structure. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonography can be used to accurately measure and evaluate the musculoskeletal structures of the pelvis of horses. The use of CT, MRI, and measurements of frozen sections provided a means of validating the ultrasonographic measurements. Reference range values determined in our study can be used to evaluate horses with suspected pelvic disease.

Animals↗

Endoscopy of the intertubercular bursa in horses.

Forelimbs from 3 anesthetized horses and 16 fresh cadaver horses were used to describe the endoscopic anatomy of the intertubercular bursa and outline the surgical portals that provide the greatest access to structures within the bursa. A lateral arthroscopic portal was made proximal to the deltoid tuberosity of the humerus into the distal bursal recess. A second portal was created proximal to the humeral tubercles that entered the proximal bursal space. These approaches provided consistent viewing and instrument access to the lateral intertuberal groove, the greater and intermediate humeral tubercles, and the synovial membrane of the proximal and distal bursal recesses. The intermediate tubercle and heavy muscle mass restricted access to the medial intertuberal groove and lesser tubercle. This technique may provide a less invasive alternative to bursotomy in the surgical management of selected horses with intertubercular bursitis. Clinical applications include cartilage debridement, fragment removal, partial synovectomy, and high-volume lavage.

Animals↗

Adrenergic, cholinergic, and nonadrenergic-noncholinergic intrinsic innervation of the jejunum in horses.

OBJECTIVE: To determine the major neurotransmitters that regulate contractile activity in the jejunum of horses. SAMPLE POPULATION: Jejunal specimens from 65 horses without gastrointestinal tract lesions. PROCEDURE: Jejunal smooth muscle strips, oriented in the plane of the circular or longitudinal muscular layer, were suspended isometrically in muscle baths. Neurotransmitter release was induced by electrical field stimulation (EFS) delivered at 30 and 70 V intensities and at various frequencies on muscle strips maintained at low or high muscle tone. To detect residual nonadrenergic-noncholinergic neurotransmission, the response of muscle to EFS in the presence of adrenergic and cholinergic blockade was compared with the response in the presence of tetrodotoxin. RESULTS: Atropine (ATR) decreased the contractile response of muscle strips to EFS under most conditions. However, ATR increased the contractile response of high-tone circular muscle. Adrenergic blockade generally increased the muscle responses to 30 V EFS and in high-tone longitudinal muscle but decreased contractile responses in high-tone circular muscle. Tetrodotoxin significantly altered the responses to EFS, compared with adrenergic and cholinergic receptor blockade. CONCLUSIONS: Acetylcholine and norepinephrine appear to be important neurotransmitters regulating smooth muscle contractility in the equine jejunum. They induce contraction and relaxation, respectively, in most muscle preparations, although they may cause opposite effects under certain conditions. In addition, nonadrenergic-noncholinergic excitatory and inhibitory influences were detected. CLINICAL RELEVANCE: Acetylcholine or norepinephrine release within the myenteric plexus of horses may alter gastrointestinal motility.

Adrenergic Agents↗

Arthroscopic surgery in a reticulated giraffe (Giraffa camelopardalis reticulata).

An 8-mo-old captive male reticulated giraffe (Giraffa camelopardalis reticulata) developed an acute lameness (grade IV/V) of the right forelimb, with swelling of the metacarpophalangeal joint. A traumatic injury was suspected based on clinical, radiographic, and arthroscopic evaluation. Several abnormalities were identified arthroscopically, including synovitis, cartilage damage, and an osteochondral fragment. Medial collateral ligament damage was also suspected based on radiographic evaluation. Arthroscopy provided a means of diagnosis and treatment of the abnormalities identified. The lameness in this giraffe resolved within 6 wk following arthroscopic surgery.

Animals↗

Treatment of a comminuted frontal-plane fracture of the distal phalanx in a horse.

Successful treatment of a comminuted frontal plane fracture of the distal phalanx in a horse is described. The bone fractured through the solar canal, close to the insertion of the deep digital flexor tendon. A hoof case was used to reduce bending and tensile stresses on the solar surface by limiting expansion of the hoof wall during weightbearing. In addition, the heel was elevated, using 3 degrees wedge pads incorporated within the hoof cast, to reduce distraction at the fracture site caused by the pull of the deep digital flexor tendon. Two casts were used over a 4-month period. Complete radiographic healing of the fracture was evident 4 months after injury. At this time the horse was lame at the trot. The owner reported the horse to be sound 7 months after injury. Reexamination 12 months after injury revealed a clinically normal foot and no lameness.

Animals↗

Influence of adrenergic and cholinergic mediators on the equine jejunum in vitro.

OBJECTIVE: To characterize the response of equine jejunal smooth muscle to adrenergic and cholinergic mediators. DESIGN: Evaluation of myogenic responses, using an in vitro model. SAMPLE POPULATION: Intestinal tissues were obtained from horses without gastrointestinal tract disorders or systemic disease. PROCEDURE: Baseline myogenic tone and amplitude and frequency of contraction were determined for suspended jejunal muscle strips. The level of adrenergic and cholinergic regulation was assessed, using atropine and adrenoceptor antagonists. The response of the muscles to norepinephrine was characterized, using adrenergic blockade and alpha- and beta-agonists. RESULTS: Adrenergic and cholinergic blockade had minimal effect on baseline myogenic activity. However, alpha 1- and beta 2-agonists induced significant (P < 0.05) decreases in the amplitude and frequency of contraction. Surprisingly, alpha 2-agonists caused an increase in the contraction amplitude of longitudinal muscle fibers (neurogenic in origin). Change in circular muscle activity was not induced by alpha 2-agonists. Norepinephrine induced a similar selective response and was inhibited by yohimbine. CONCLUSIONS: Baseline jejunal activity appears to be myogenic in origin and can function independently of sympathetic and parasympathetic input. However, intestinal smooth muscle can be affected by adrenergic agonists and potentially by increased concentrations of circulating catecholamines. Norepinephrine may act by altering the activity of other neurotransmitters. Differing responses between circular and longitudinal muscle fibers indicates a need to evaluate both components. CLINICAL RELEVANCE: Selective alpha 2-agonists may be potentially useful for motility modification of the equine jejunum. Therapeutic use of adrenergic blockade will be effective only in cases of increased adrenergic stimulation.

Acetylcholine↗

Aneurysm of the cranial mesenteric artery in a cow.

Exploratory laparotomy of an adult dairy cow, examined because of acute signs of persistent abdominal pain, revealed a firm pulsatile mass with associated fremitus just distal to the origin of the cranial mesenteric artery. The cow died acutely 2.5 days after surgery. A dilated, thin-walled, sacculated aneurysm, which had ruptured, was located along the proximal portion of the cranial mesenteric artery. It was postulated that the aneurysm developed secondary to structural defects in the arterial wall, but caused no clinical signs until enlargement and local tissue stretching or circulatory disturbances caused intestinal ischemia, resulting in abdominal pain. Aneurysms of visceral arteries in cattle should be considered as another differential diagnosis for signs of abdominal pain after more common causes such as severe bloat, mesenteric root volvulus, intussusception, cecal dilatation/volvulus, and uterine torsion have been excluded.

Abdominal Pain↗

Nonsurgical treatment of cubital subchondral cyst-like lesions in horses: seven cases (1983-1987).

Subchondral cyst-like lesions of the cubital joint were diagnosed in 7 horses at the teaching hospital between 1983 and 1987. Diagnosis of the lesions was made by administration of intra-articular local anesthesia and/or radiographically. Initial treatment for all horses consisted of stall rest for 60 to 90 days. In addition, 2 horses were administered sodium hyaluronate intra-articularly, 1 horse was given injections of polysulfated glycosaminoglycans IM, and 1 horse was given phenylbutazone orally. Follow-up information was compiled 6 weeks to 4 years after initial examination. At the time of follow-up inquiry, 6 horses were sound for intended use and only 1 horse became lame when exercised. A logical approach to choice of surgical or nonsurgical treatment is proposed on the basis of these findings and those reported in the literature.

Anesthesia, Local↗

Thermography as an aid to the clinical lameness evaluation.

Thermography has been shown to be a practical aid in the clinical evaluation of lameness. This modality specifically increases the accuracy of diagnosis. Thermography represents skin temperature, usually pictorially. The techniques involve contacting and noncontacting modalities. Noncontacting thermography, which detects infrared radiation, is the most accurate. In order to be accurate, thermography must be performed in a temperature-controlled, draft-free area. The area should be protected from sunlight to avoid erroneous heating of the skin, and the hair length should be uniform. Thermography detects heat before it is perceptible during routine physical examination; therefore, it is useful for early detection of laminitis, stress fractures, and tendinitis. It offers a noninvasive means of evaluating the blood supply to an injured part and offers one of the only reliable means to evaluate blood flow to the foot of horses with navicular syndrome. Thermography also is useful for the early identification of stress injuries to the contralateral limb of convalescing orthopedic patients. Thermography is an excellent adjunct to clinical and radiographic examination. It is complementary to other imaging techniques such as ultrasonography and scintigraphy.

Animals↗

Ethmoidal hematoma in nine horses.

Ethmoidal hematoma was diagnosed in 9 horses by results of physical examination, endoscopy, radiography, and histologic examination of tissues. The horses had stertorous breathing (n = 4) or intermittently sanguineous nasal discharge (n = 7). All horses underwent sinusotomy and extirpation of the lesion. At reexamination 15 to 104 months after surgery (mean, 61 months), 3 horses had recurrence of ethmoidal hematoma, and 1 horse had ethmoidal hematoma involving the contralateral ethmoturbinates. One of the horses with recurrence of ethmoidal hematoma also developed a contralateral lesion; both lesions recurred and additional surgeries were performed.

Animals↗

Diagnosis and treatment of the navicular syndrome in horses.

Navicular syndrome can be treated in a variety of ways. This is related to the fact that it has a variety of causes. Prognostically, most horses will improve with treatment. One can expect about 50 per cent of the horses to become useably sound for 1 year, no matter what treatment is used. The disease is progressive, and affected horses eventually will need to be retired because of lameness. The author's therapeutic approach is to utilize shoeing as the primary therapy. Shoeing is performed to correct structural problems and to ensure that shoeing is physiologically sound. Nonsteroidal anti-inflammatory drugs are not used unless radical changes have been made in the shoeing. In cases of confirmed distal interphalangeal joint synovitis, either sodium hyaluronate or polysulfated glycosaminoglycans will be used in conjunction with shoeing. In cases where decreased circulation is documented, isoxsuprine hydrochloride will be administered if shoeing alone has not improved the horse within 6 weeks. If therapy does not improve the horse within 6 to 12 weeks, palmar digital neurectomy is recommended.

Animals↗

Injuries to the cranial cruciate ligament and associated structures: summary of clinical, radiographic, arthroscopic and pathological findings from 10 horses.

The clinical, radiographic, arthroscopic and pathological findings of 10 horses with injury to the cranial cruciate ligament are presented. The most consistent clinical signs included moderate to severe distension of the femoropatellar joint and a Grade III to a Grade V out of V lameness. Craniocaudal instability could be elicited in five horses under general anaesthesia and in one conscious horse. Radiographic evaluation of the stifles revealed that avulsion fracture of the medial intercondylar eminence was the most common finding in six out of 10 horses. Arthroscopic examination of the affected femorotibial joints were performed in five horses. This confirmed the presumptive diagnosis of cranial cruciate ligament injury or rupture. Post mortem examinations were performed on two horses which documented partial tears of the cranial cruciate ligament.

Animals↗