Reasons for performing study: The longissimus dorsi is the largest muscle in the equine back and ... more Reasons for performing study: The longissimus dorsi is the largest muscle in the equine back and plays an important role in locomotor ability and performance in the horse. In vivo studies suggest that the mechanical function varies between different muscle segments, in part determined by anatomy. It is possible therefore that variations in function reflect variations in the anatomy of the longissimus dorsi along its length.Objectives: To identify if there are regional variations in muscle architecture of the longissimus dorsi.Methods: Computed tomography scans were obtained from 8 cadaver backs to identify the cross-sectional area and volume of the muscle. The 3D orientations of the muscle fascicles were quantified in situ by their direction cosines using a magnetic digitisation system.Results: Mean ± s.e. volume of the muscle was 2.34 ± 0.18 l for each side and mean length of the vertebral column from T4 to L6 dorsal spinous processes was 56.57 ± 2.0 cm. There were significant differences in the cross-sectional area and the moment arm lengths between muscle segments (P<0.05). In the lumbar region, the mediolateral moment arms were 2–3 times greater than the dorsoventral moment arms. There were significant variations in the direction cosines (n = 7129) between muscle segments and between different regions within each segment (P<0.05).Potential relevance: These observations indicate that the muscle fascicle architecture predisposes the longissimus dorsi to different functions both along its length and between different regions within each segment. Detailed 3D anatomical measures of the structure with in vivo measures of function (back motion and muscle activity) will be investigated in further studies.
The diagnostic and prognostic value of nuclear scintigraphy with technetium-99m-labelled hexameth... more The diagnostic and prognostic value of nuclear scintigraphy with technetium-99m-labelled hexamethyl-propyleneamine oxime-labelled leucocytes was assessed in 17 horses with weight loss due to gastrointestinal malabsorption by comparing the results with the results obtained from 13 normal control horses. Intestinal uptake of activity was detected in 12 of the 17 cases but none of the control horses. The technique was therefore specific for intestinal pathology, but failed to detect some horses that might have had intestinal pathology. No indications of the horses&#39; specific pathology were obtained, and their prognosis or response to treatment could not be predicted.
In this article, we describe student perceptions of the value of a short, compulsory research pro... more In this article, we describe student perceptions of the value of a short, compulsory research project embedded in a clinical degree program, the research output in terms of publications, and the factors influencing this. It was hypothesized that student attitudes toward the project, student perceptions of how much the project contributed to their generic skills, and the number of publications submitted or prepared for submission would be associated with perceived quality of supervision, perceived difficulty of the project, career plans, and attitude before commencement of the project. We explored this using a questionnaire comprising 30 questions that included demographics, Likert scales, and categorical responses. Student attitudes toward research were found to be associated with student attitude before the start of the project, perceived difficulty of the project, perceived quality of supervision, and perceived relevance to the profession. Students thought that the research project contributed most to the skills of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;information gathering&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;critical evaluation&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and the least to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;teamwork,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;problem solving,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;oral communication.&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; Research output was significantly linked to perceived quality of supervision and the help students received with data analysis and data collection, though not with the project report itself. In conclusion, although the success of the research project was influenced by many factors, the perceived quality of supervision influenced all three outcome measures. Therefore it is clear that optimization of this aspect offers the most scope for enhancing the student learning experience.
Horses that had been trimmed and shod by apprentice farriers were sourced from the Royal School o... more Horses that had been trimmed and shod by apprentice farriers were sourced from the Royal School of Military Engineering, Melton Mowbray (37 horses) and from the Household Cavalry, Knightsbridge (54 horses). The lateral and medial hoof wall angles of both forelimbs were measured using a Ruidoso hoof gauge by the same operator. The difference between the lateral and medial hoof wall angles for each horse was calculated and the results were compared between right-handed and left-handed farriers using the Mann-Whitney U test (P&lt;0.05). There was a significant difference in the mediolateral hoof balance obtained between right-handed and left-handed farriers for each forelimb (P&lt;0.001). Right-handed farriers were shown to create an imbalance in 47 per cent of left forelimbs and 46 per cent of right forelimbs assessed, while left-handed farriers created an imbalance in 41 per cent of left forelimbs and 71 per cent of right forelimbs. The tendency was for right-handed farriers to over-trim the medial (inner) aspect of the left forelimb and the lateral (outer) aspect of the right forelimb; the reverse was demonstrated for left-handed farriers. Performing a risk ratio confirmed these findings.
Joint injections are commonly used in equine practice for diagnosis and treatment of joint disord... more Joint injections are commonly used in equine practice for diagnosis and treatment of joint disorders. Performing joint injections is hence an essential skill for equine practitioners. However, opportunities for veterinary students to practice this skill are often scarce in veterinary curricula. The aim of this study was to design and validate an equine joint injection simulator. We hypothesized that the simulator will enhance student ability and confidence in performing joint injections. The simulator was constructed around an equine forelimb skeleton with soft tissues rebuilt using building foam and rubber bands. An electrical circuit including a buzzer, a battery, wire wool in the joints, and a hypodermic needle at the end of the cable was incorporated. If the students placed the needle into the joint correctly, instant auditory feedback was provided by the buzzer. To validate the simulator, 45 veterinary students were allocated to three groups: cadaver limb, textbook, or simulator. Students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; ability to perform joint injections was tested and students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; opinions were evaluated with a questionnaire. The proportion of students performing a metacarpophalangeal (MCP) joint injection correctly was significantly higher in the cadaver (93%) and simulator (76%) groups compared to the textbook group (50%). There was no significant difference between groups for performing a distal interphalangeal (DIP) joint injection correctly. Students rated the learning experience with the cadaver and simulator group high and with the textbook group low. The joint injection simulator represents an affordable teaching aid that allows students to repeatedly practice this skill in their own time with immediate feedback.
Joint effusion is one of the classic radiographic signs of osteoarthritis, but no information is ... more Joint effusion is one of the classic radiographic signs of osteoarthritis, but no information is available regarding clinicians&amp;amp;amp;amp;#39; ability to detect joint effusion radiographically. This study determined the accuracy and precision of experienced and inexperienced observers in detecting joint effusion of the distal interphalangeal (DIP), metacarpophalangeal (MCP) and midcarpal joints on radiographs. Fresh cadaverous forelimbs were loaded in a material testing machine to mimic a standing horse. The joints were gradually distended and lateromedial and dorsopalmar radiographs were acquired. The images were assessed by three experienced and three inexperienced observers. This study showed that the sensitivity was high for both groups for all joints and projections. Specificity was high for the experienced group but low for the inexperienced group. There was a significant positive correlation between joint distension and severity of joint effusion when reported by experienced observersfor most views (except DIP joint), but only for the MCP joint for inexperienced observers. Interoperator agreement was poor to fair for the experienced group and poor for the inexperienced group. In conclusion, the accuracy and precision of grading joint effusion on radiographs was highly subjective and related to experience.
Criteria for the radiographic evaluation of navicular bones in horses have been published to stan... more Criteria for the radiographic evaluation of navicular bones in horses have been published to standardise classification of radiographic signs. However, intra- and interobserver agreement have not been established. To determine intra- and interobserver agreement in the evaluation of radiographic and computed tomographic (CT) navicular changes. It was hypothesised that: 1) intraobserver agreement would be better than interobserver agreement; 2) agreement would be better for CT than for radiography; and 3) pathological changes would be recognised with greater certainty with CT. Radiographs and CT scans of 60 cadaver navicular bones were evaluated by 3 observers using published criteria. A subset of 30 studies was evaluated twice by one observer. Agreement was tested using the kappa statistic. Certainty about pathological changes was evaluated by giving the observers the option to choose &#39;not sure&#39;. Agreement varied from poor to almost perfect for radiographic evaluation and from poor to substantial for CT evaluation. For radiographic evaluation mean interobserver agreement was fair, as it was for CT evaluation. For radiographic evaluation mean intraobserver agreement was moderate as it was for CT evaluation. Pathological changes were evaluated with greater certainty on CT scans compared to radiographs; however, this was not associated with improved agreement. Variations in classification of navicular lesions in radiographic and CT studies were considerable between and within observers and challenge the use of such studies for diagnostic and prognostic purposes. The results of this study allowed the identification of evaluation criteria with sufficient precision to be useful for navicular bone evaluation.
Reasons for study: Detailed anatomy of the equine cervical articular process joints (APJs) has re... more Reasons for study: Detailed anatomy of the equine cervical articular process joints (APJs) has received little attention in the literature and yet disorders of this joint have been linked to spinal cord compression resulting in severe clinical signs such as ataxia and weakness. This study aimed to describe the 3D anatomy of the APJ in relation to the spinal cord in the horse.Hypothesis: Artificial distension of the APJ causes the joint pouches to extend into the vertebral canal, with the potential for APJ effusion to cause spinal cord compressive disease.Methods: Six cadaveric necks (C1–C7) of clinically normal horses were used in this study. Computed tomography scans of the cervical APJ were acquired after injection of a negative contrast agent to maximal distension. The resulting images were semi-automatically segmented using greyscale thresholding and reconstructed in 3D by polygonal surface meshing. The 3D reconstructions were used to assess the topographic anatomy of the APJ in relation to the spinal cord and to measure joint volume at each cervical vertebra in relation to vertebrae size.Results: Joint volume varied significantly between joint location (P<0.0001) and was positively correlated to the vertebral site (from cranial to caudal) (r = 0.781, P<0.0001). After distension, the medial outpouch of the APJ extended towards the vertebral canal from a dorsolateral location but in none of the 6 horses was there apparent compression of the dura mater surrounding the spinal cord. There was no significant difference in the extent of medial outpouch at any vertebral level (P = 0.104). Flexion of the neck resulted in minor changes to the shape of the APJ but did not result in the medial outpouch encroaching any closer to the spinal cord.Conclusions: From this study, it appears that in the absence of any other soft tissue or bony changes an effusion of the APJ is unlikely to cause spinal cord compression. However, given that the APJ and spinal cord are in close approximation, in the presence of other anatomical changes, an effusion may have the potential to cause compression.Potential relevance: This study confirms that the APJ extend into the dorsolateral aspect of the vertebral canal in a ventromedial direction, suggesting that oblique myelographic views are recommended for the diagnosis of spinal cord compression when pathology of the APJ is suspected.
Reasons for performing study: Currently available sedatives depress cardiopulmonary function cons... more Reasons for performing study: Currently available sedatives depress cardiopulmonary function considerably; therefore, it is important to search for new, less depressive sedatives. The study was performed to assess duration and intensity of cardiopulmonary side effects of a new sedative, dexmedetomidine (DEX), in horses.Objectives: To study pharmacokinetics and cardiopulmonary effects of i.v. DEX.Methods: Pharmacokinetics of 3.5 μg/kg bwt i.v. DEX were studied in a group of 8 mature (mean age 4.4 years) and 6 old ponies (mean age 20 years). Cardiopulmonary data were recorded in mature ponies before and 5, 10, 20, 30, 45 and 60 mins after administration of DEX 3.5 μg/kg bwt i.v. Data were analysed using ANOVA for repeated measures, and where appropriate Dunnett's t test was used to detect differences from resting values (P<0.05).Results: Within 2 h after DEX administration, plasma levels were beyond limits of quantification (0.05 ng/ml). Mean values for kinetic parameters for mature and old ponies were: Cmax (ng/ml) 4.6 and 3.8, t1/2 (min) 19.8 and 28.9 and AUC (ng.min/ml) 34.5 and 44.3, respectively. Heart rate, central venous pressure, pulmonary artery pressure and pulmonary capillary wedge pressure did not change significantly compared to presedation values throughout the 60 min observation period. Compared to presedation values, stroke volume and mixed venous PO2 were reduced for the first 5 mins, paralleled by an increase in systemic and pulmonary vascular resistance. Cardiac index was reduced for the first 10 mins, arterial blood pressures at 20, 30 and 45 mins and respiratory rate throughout the 60 min observation period, but no change in arterial PO2 or PCO2 occurred.Conclusions: DEX administration i.v. causes similar cardiopulmonary changes to those caused by other alpha-2 adrenoceptor agonists, but of very short duration. DEX is redistributed particularly rapidly.Potential relevance: DEX might be safer for sedation of horses because of its very short-lasting cardiopulmonary side effects. For long duration sedation, its kinetics favour its use as a continuous infusion.
Reasons for performing study: Hindlimb lameness is common and can be difficult to diagnose or qua... more Reasons for performing study: Hindlimb lameness is common and can be difficult to diagnose or quantify in evaluating response to nerve blocks. An objective measure of lameness can also be used to evaluate the effectiveness of the treatment's contribution to evidence-based medicine. The inertial sensor system can be used to capture 6 degree of freedom movement during over ground locomotion and here was used to quantify tuber coxae movement in nonlame and lame horses.Hypothesis: Tuber coxae movement is useful for discriminating between nonlame and lame horses.Objectives: To measure left and right tuber coxae movement in lame and nonlame horses during over ground locomotion and to implement a linear discriminant analysis to discriminate between lame and nonlame horses.Methods: Two inertial sensors were attached to the skin over left and right tuber coxae of 21 horses (9 mildly and 12 not lame). Horses were trotted on a hard surface. A total of 1021 strides were collected. For each stride 34 features were extracted from the dorsoventral and craniocaudal movement and used in 2 different classification scenarios (lame vs. nonlame or left lame, right lame and nonlame) using linear discriminant analysis.Results: Six degree of freedom inertial sensors were successfully used to collect kinematic data continuously from left and right tuber coxae in horses during over ground locomotion. These data were used for an automated classification of lameness. In the first scenario, a sensitivity of 89% was achieved with a specificity of 75%. In the second scenario, all horses could be correctly assigned to the correct class in a simple 3 class reclassification test.Potential relevance: A mobile system that reliably detects and quantifies hindlimb lameness in horses during unconstrained locomotion could be a valuable tool to perform an evidence-based assessment of lameness in horses in a clinical setting, e.g. before and after nerve blocks or before and after surgery.
Reasons for performing study: Visual assessment of horses' movements is subjective, affected by b... more Reasons for performing study: Visual assessment of horses' movements is subjective, affected by bias and dependent on the level of experience of the assessor. However, to date there are no data available on the ability of the human visual system to recognise (a)symmetry in moving objects.Objectives: To investigate, using visual lameness assessment, the limits of human perception and the ability of experienced and nonexperienced individuals to detect asymmetry in 2 moving objects simulating hindlimb lameness in the horse.Methods: Twelve experienced individuals (equine and small animal clinicians), and 24 nonexperienced individuals (undergraduate veterinary students) were presented with computer simulations showing 2 ‘tuber coxae markers’ created using data from both lame and nonperceptibly lame horses, as well as artificial data based on a sine wave. Individuals were asked to classify as symmetrical or asymmetrical, and then rank based on the grade of perceived asymmetry. Repeatability and learning effect were evaluated by repeating the tests on a subset of subjects.Results: The threshold for detection of movement asymmetry was found to be approximately 25% difference in amplitude between the 2 moving objects for all individuals. There was no significant difference between experienced and nonexperienced individuals in the ability to detect asymmetry in the simulations based on artificial data. However, the percentage of correct answers was higher for experienced compared to nonexperienced individuals for simulations based on data from real lame horses.Conclusions: There was a significant difference between experienced and nonexperienced individuals in the ability to identify asymmetric movement based on the pattern seen in a lame horse, as opposed to an artificial pattern for which all individuals showed similar performance.Potential relevance: The study provides the basis for the development of computer simulations that could aid in training veterinarians in the diagnosis of lameness and, even, the objective assessment of expertise in this field.
Reasons for performing study: The longissimus dorsi is the largest muscle in the equine back and ... more Reasons for performing study: The longissimus dorsi is the largest muscle in the equine back and plays an important role in locomotor ability and performance in the horse. In vivo studies suggest that the mechanical function varies between different muscle segments, in part determined by anatomy. It is possible therefore that variations in function reflect variations in the anatomy of the longissimus dorsi along its length.Objectives: To identify if there are regional variations in muscle architecture of the longissimus dorsi.Methods: Computed tomography scans were obtained from 8 cadaver backs to identify the cross-sectional area and volume of the muscle. The 3D orientations of the muscle fascicles were quantified in situ by their direction cosines using a magnetic digitisation system.Results: Mean ± s.e. volume of the muscle was 2.34 ± 0.18 l for each side and mean length of the vertebral column from T4 to L6 dorsal spinous processes was 56.57 ± 2.0 cm. There were significant differences in the cross-sectional area and the moment arm lengths between muscle segments (P<0.05). In the lumbar region, the mediolateral moment arms were 2–3 times greater than the dorsoventral moment arms. There were significant variations in the direction cosines (n = 7129) between muscle segments and between different regions within each segment (P<0.05).Potential relevance: These observations indicate that the muscle fascicle architecture predisposes the longissimus dorsi to different functions both along its length and between different regions within each segment. Detailed 3D anatomical measures of the structure with in vivo measures of function (back motion and muscle activity) will be investigated in further studies.
The diagnostic and prognostic value of nuclear scintigraphy with technetium-99m-labelled hexameth... more The diagnostic and prognostic value of nuclear scintigraphy with technetium-99m-labelled hexamethyl-propyleneamine oxime-labelled leucocytes was assessed in 17 horses with weight loss due to gastrointestinal malabsorption by comparing the results with the results obtained from 13 normal control horses. Intestinal uptake of activity was detected in 12 of the 17 cases but none of the control horses. The technique was therefore specific for intestinal pathology, but failed to detect some horses that might have had intestinal pathology. No indications of the horses&#39; specific pathology were obtained, and their prognosis or response to treatment could not be predicted.
In this article, we describe student perceptions of the value of a short, compulsory research pro... more In this article, we describe student perceptions of the value of a short, compulsory research project embedded in a clinical degree program, the research output in terms of publications, and the factors influencing this. It was hypothesized that student attitudes toward the project, student perceptions of how much the project contributed to their generic skills, and the number of publications submitted or prepared for submission would be associated with perceived quality of supervision, perceived difficulty of the project, career plans, and attitude before commencement of the project. We explored this using a questionnaire comprising 30 questions that included demographics, Likert scales, and categorical responses. Student attitudes toward research were found to be associated with student attitude before the start of the project, perceived difficulty of the project, perceived quality of supervision, and perceived relevance to the profession. Students thought that the research project contributed most to the skills of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;information gathering&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;critical evaluation&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and the least to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;teamwork,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;problem solving,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;oral communication.&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; Research output was significantly linked to perceived quality of supervision and the help students received with data analysis and data collection, though not with the project report itself. In conclusion, although the success of the research project was influenced by many factors, the perceived quality of supervision influenced all three outcome measures. Therefore it is clear that optimization of this aspect offers the most scope for enhancing the student learning experience.
Horses that had been trimmed and shod by apprentice farriers were sourced from the Royal School o... more Horses that had been trimmed and shod by apprentice farriers were sourced from the Royal School of Military Engineering, Melton Mowbray (37 horses) and from the Household Cavalry, Knightsbridge (54 horses). The lateral and medial hoof wall angles of both forelimbs were measured using a Ruidoso hoof gauge by the same operator. The difference between the lateral and medial hoof wall angles for each horse was calculated and the results were compared between right-handed and left-handed farriers using the Mann-Whitney U test (P&lt;0.05). There was a significant difference in the mediolateral hoof balance obtained between right-handed and left-handed farriers for each forelimb (P&lt;0.001). Right-handed farriers were shown to create an imbalance in 47 per cent of left forelimbs and 46 per cent of right forelimbs assessed, while left-handed farriers created an imbalance in 41 per cent of left forelimbs and 71 per cent of right forelimbs. The tendency was for right-handed farriers to over-trim the medial (inner) aspect of the left forelimb and the lateral (outer) aspect of the right forelimb; the reverse was demonstrated for left-handed farriers. Performing a risk ratio confirmed these findings.
Joint injections are commonly used in equine practice for diagnosis and treatment of joint disord... more Joint injections are commonly used in equine practice for diagnosis and treatment of joint disorders. Performing joint injections is hence an essential skill for equine practitioners. However, opportunities for veterinary students to practice this skill are often scarce in veterinary curricula. The aim of this study was to design and validate an equine joint injection simulator. We hypothesized that the simulator will enhance student ability and confidence in performing joint injections. The simulator was constructed around an equine forelimb skeleton with soft tissues rebuilt using building foam and rubber bands. An electrical circuit including a buzzer, a battery, wire wool in the joints, and a hypodermic needle at the end of the cable was incorporated. If the students placed the needle into the joint correctly, instant auditory feedback was provided by the buzzer. To validate the simulator, 45 veterinary students were allocated to three groups: cadaver limb, textbook, or simulator. Students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; ability to perform joint injections was tested and students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; opinions were evaluated with a questionnaire. The proportion of students performing a metacarpophalangeal (MCP) joint injection correctly was significantly higher in the cadaver (93%) and simulator (76%) groups compared to the textbook group (50%). There was no significant difference between groups for performing a distal interphalangeal (DIP) joint injection correctly. Students rated the learning experience with the cadaver and simulator group high and with the textbook group low. The joint injection simulator represents an affordable teaching aid that allows students to repeatedly practice this skill in their own time with immediate feedback.
Joint effusion is one of the classic radiographic signs of osteoarthritis, but no information is ... more Joint effusion is one of the classic radiographic signs of osteoarthritis, but no information is available regarding clinicians&amp;amp;amp;amp;#39; ability to detect joint effusion radiographically. This study determined the accuracy and precision of experienced and inexperienced observers in detecting joint effusion of the distal interphalangeal (DIP), metacarpophalangeal (MCP) and midcarpal joints on radiographs. Fresh cadaverous forelimbs were loaded in a material testing machine to mimic a standing horse. The joints were gradually distended and lateromedial and dorsopalmar radiographs were acquired. The images were assessed by three experienced and three inexperienced observers. This study showed that the sensitivity was high for both groups for all joints and projections. Specificity was high for the experienced group but low for the inexperienced group. There was a significant positive correlation between joint distension and severity of joint effusion when reported by experienced observersfor most views (except DIP joint), but only for the MCP joint for inexperienced observers. Interoperator agreement was poor to fair for the experienced group and poor for the inexperienced group. In conclusion, the accuracy and precision of grading joint effusion on radiographs was highly subjective and related to experience.
Criteria for the radiographic evaluation of navicular bones in horses have been published to stan... more Criteria for the radiographic evaluation of navicular bones in horses have been published to standardise classification of radiographic signs. However, intra- and interobserver agreement have not been established. To determine intra- and interobserver agreement in the evaluation of radiographic and computed tomographic (CT) navicular changes. It was hypothesised that: 1) intraobserver agreement would be better than interobserver agreement; 2) agreement would be better for CT than for radiography; and 3) pathological changes would be recognised with greater certainty with CT. Radiographs and CT scans of 60 cadaver navicular bones were evaluated by 3 observers using published criteria. A subset of 30 studies was evaluated twice by one observer. Agreement was tested using the kappa statistic. Certainty about pathological changes was evaluated by giving the observers the option to choose &#39;not sure&#39;. Agreement varied from poor to almost perfect for radiographic evaluation and from poor to substantial for CT evaluation. For radiographic evaluation mean interobserver agreement was fair, as it was for CT evaluation. For radiographic evaluation mean intraobserver agreement was moderate as it was for CT evaluation. Pathological changes were evaluated with greater certainty on CT scans compared to radiographs; however, this was not associated with improved agreement. Variations in classification of navicular lesions in radiographic and CT studies were considerable between and within observers and challenge the use of such studies for diagnostic and prognostic purposes. The results of this study allowed the identification of evaluation criteria with sufficient precision to be useful for navicular bone evaluation.
Reasons for study: Detailed anatomy of the equine cervical articular process joints (APJs) has re... more Reasons for study: Detailed anatomy of the equine cervical articular process joints (APJs) has received little attention in the literature and yet disorders of this joint have been linked to spinal cord compression resulting in severe clinical signs such as ataxia and weakness. This study aimed to describe the 3D anatomy of the APJ in relation to the spinal cord in the horse.Hypothesis: Artificial distension of the APJ causes the joint pouches to extend into the vertebral canal, with the potential for APJ effusion to cause spinal cord compressive disease.Methods: Six cadaveric necks (C1–C7) of clinically normal horses were used in this study. Computed tomography scans of the cervical APJ were acquired after injection of a negative contrast agent to maximal distension. The resulting images were semi-automatically segmented using greyscale thresholding and reconstructed in 3D by polygonal surface meshing. The 3D reconstructions were used to assess the topographic anatomy of the APJ in relation to the spinal cord and to measure joint volume at each cervical vertebra in relation to vertebrae size.Results: Joint volume varied significantly between joint location (P<0.0001) and was positively correlated to the vertebral site (from cranial to caudal) (r = 0.781, P<0.0001). After distension, the medial outpouch of the APJ extended towards the vertebral canal from a dorsolateral location but in none of the 6 horses was there apparent compression of the dura mater surrounding the spinal cord. There was no significant difference in the extent of medial outpouch at any vertebral level (P = 0.104). Flexion of the neck resulted in minor changes to the shape of the APJ but did not result in the medial outpouch encroaching any closer to the spinal cord.Conclusions: From this study, it appears that in the absence of any other soft tissue or bony changes an effusion of the APJ is unlikely to cause spinal cord compression. However, given that the APJ and spinal cord are in close approximation, in the presence of other anatomical changes, an effusion may have the potential to cause compression.Potential relevance: This study confirms that the APJ extend into the dorsolateral aspect of the vertebral canal in a ventromedial direction, suggesting that oblique myelographic views are recommended for the diagnosis of spinal cord compression when pathology of the APJ is suspected.
Reasons for performing study: Currently available sedatives depress cardiopulmonary function cons... more Reasons for performing study: Currently available sedatives depress cardiopulmonary function considerably; therefore, it is important to search for new, less depressive sedatives. The study was performed to assess duration and intensity of cardiopulmonary side effects of a new sedative, dexmedetomidine (DEX), in horses.Objectives: To study pharmacokinetics and cardiopulmonary effects of i.v. DEX.Methods: Pharmacokinetics of 3.5 μg/kg bwt i.v. DEX were studied in a group of 8 mature (mean age 4.4 years) and 6 old ponies (mean age 20 years). Cardiopulmonary data were recorded in mature ponies before and 5, 10, 20, 30, 45 and 60 mins after administration of DEX 3.5 μg/kg bwt i.v. Data were analysed using ANOVA for repeated measures, and where appropriate Dunnett's t test was used to detect differences from resting values (P<0.05).Results: Within 2 h after DEX administration, plasma levels were beyond limits of quantification (0.05 ng/ml). Mean values for kinetic parameters for mature and old ponies were: Cmax (ng/ml) 4.6 and 3.8, t1/2 (min) 19.8 and 28.9 and AUC (ng.min/ml) 34.5 and 44.3, respectively. Heart rate, central venous pressure, pulmonary artery pressure and pulmonary capillary wedge pressure did not change significantly compared to presedation values throughout the 60 min observation period. Compared to presedation values, stroke volume and mixed venous PO2 were reduced for the first 5 mins, paralleled by an increase in systemic and pulmonary vascular resistance. Cardiac index was reduced for the first 10 mins, arterial blood pressures at 20, 30 and 45 mins and respiratory rate throughout the 60 min observation period, but no change in arterial PO2 or PCO2 occurred.Conclusions: DEX administration i.v. causes similar cardiopulmonary changes to those caused by other alpha-2 adrenoceptor agonists, but of very short duration. DEX is redistributed particularly rapidly.Potential relevance: DEX might be safer for sedation of horses because of its very short-lasting cardiopulmonary side effects. For long duration sedation, its kinetics favour its use as a continuous infusion.
Reasons for performing study: Hindlimb lameness is common and can be difficult to diagnose or qua... more Reasons for performing study: Hindlimb lameness is common and can be difficult to diagnose or quantify in evaluating response to nerve blocks. An objective measure of lameness can also be used to evaluate the effectiveness of the treatment's contribution to evidence-based medicine. The inertial sensor system can be used to capture 6 degree of freedom movement during over ground locomotion and here was used to quantify tuber coxae movement in nonlame and lame horses.Hypothesis: Tuber coxae movement is useful for discriminating between nonlame and lame horses.Objectives: To measure left and right tuber coxae movement in lame and nonlame horses during over ground locomotion and to implement a linear discriminant analysis to discriminate between lame and nonlame horses.Methods: Two inertial sensors were attached to the skin over left and right tuber coxae of 21 horses (9 mildly and 12 not lame). Horses were trotted on a hard surface. A total of 1021 strides were collected. For each stride 34 features were extracted from the dorsoventral and craniocaudal movement and used in 2 different classification scenarios (lame vs. nonlame or left lame, right lame and nonlame) using linear discriminant analysis.Results: Six degree of freedom inertial sensors were successfully used to collect kinematic data continuously from left and right tuber coxae in horses during over ground locomotion. These data were used for an automated classification of lameness. In the first scenario, a sensitivity of 89% was achieved with a specificity of 75%. In the second scenario, all horses could be correctly assigned to the correct class in a simple 3 class reclassification test.Potential relevance: A mobile system that reliably detects and quantifies hindlimb lameness in horses during unconstrained locomotion could be a valuable tool to perform an evidence-based assessment of lameness in horses in a clinical setting, e.g. before and after nerve blocks or before and after surgery.
Reasons for performing study: Visual assessment of horses' movements is subjective, affected by b... more Reasons for performing study: Visual assessment of horses' movements is subjective, affected by bias and dependent on the level of experience of the assessor. However, to date there are no data available on the ability of the human visual system to recognise (a)symmetry in moving objects.Objectives: To investigate, using visual lameness assessment, the limits of human perception and the ability of experienced and nonexperienced individuals to detect asymmetry in 2 moving objects simulating hindlimb lameness in the horse.Methods: Twelve experienced individuals (equine and small animal clinicians), and 24 nonexperienced individuals (undergraduate veterinary students) were presented with computer simulations showing 2 ‘tuber coxae markers’ created using data from both lame and nonperceptibly lame horses, as well as artificial data based on a sine wave. Individuals were asked to classify as symmetrical or asymmetrical, and then rank based on the grade of perceived asymmetry. Repeatability and learning effect were evaluated by repeating the tests on a subset of subjects.Results: The threshold for detection of movement asymmetry was found to be approximately 25% difference in amplitude between the 2 moving objects for all individuals. There was no significant difference between experienced and nonexperienced individuals in the ability to detect asymmetry in the simulations based on artificial data. However, the percentage of correct answers was higher for experienced compared to nonexperienced individuals for simulations based on data from real lame horses.Conclusions: There was a significant difference between experienced and nonexperienced individuals in the ability to identify asymmetric movement based on the pattern seen in a lame horse, as opposed to an artificial pattern for which all individuals showed similar performance.Potential relevance: The study provides the basis for the development of computer simulations that could aid in training veterinarians in the diagnosis of lameness and, even, the objective assessment of expertise in this field.
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Papers by Renate Weller