Effect of video angle on detection of induced front limb lameness in horses.

BACKGROUND: Lameness examinations are commonly performed in equine medicine. Advancements in digital technology have increased the use of video recordings for lameness assessment, however, standardization of ideal video angle is not available yielding videos of poor diagnostic quality. The objective of this study was to evaluate the effect of video angle on the subjective assessment of front limb lameness. A randomized, blinded, crossover study was performed. Six horses with and without mechanically induced forelimb solar pain were recorded using 9 video angles including horses trotting directly away and towards the video camera, horses trotting away and towards a video camera placed to the left and right side of midline, and horses trotting in a circle with the video camera placed on the inside and outside of the circle. Videos were randomized and assessed by three expert equine veterinarians using a 0-5 point scoring system. Objective lameness parameters were collected using a body-mounted inertial sensor system (Lameness Locator®, Equinosis LLC). Interobserver agreement for subjective lameness scores and ease of grading scores were determined. RESULTS: Induction of lameness was successful in all horses. There was excellent agreement between objective lameness parameters and subjective lameness scores (AUC of the ROC = 0.87). For horses in the "lame" trials, interobserver agreement was moderate for video angle 2 when degree of lameness was considered and perfect for video angle 2 and 9 when lameness was considered as a binary outcome. All other angles had no to fair agreement. For horses in the "sound" trials, interobserver agreement was perfect for video angle 5. All other video angles had slight to moderate agreement. CONCLUSIONS: When video assessment of forelimb lameness is required, a video of the horse trotting directly towards the video camera at a minimum is recommended. Other video angles may provide supportive information regarding lameness characteristics.

Objective evaluation for analgesia of the distal interphalangeal joint, the navicular bursa and perineural analgesia in horses with naturally occurring forelimb lameness localised to the foot.

BACKGROUND: The outcome and interpretation of intra-synovial diagnostic analgesia of the distal interphalangeal joint (DIPJ) and the navicular bursa (NB) remain in dispute, and no objective studies have been carried out to establish the percentage of improvement over time from these two analgesia techniques. OBJECTIVES: To investigate the qualitative and time-dependent outcome of DIPJ-A and NB-A in naturally occurring forelimb lameness. STUDY DESIGN: Case series. METHODS: Twenty-three clinical cases with forelimb lameness were evaluated objectively using a body mounted inertial sensor system (BMIS). Lameness was localised to the foot with a palmar digital nerve block and/or an abaxial sesamoidean nerve block on day 1, and analgesia of the DIPJ (DIPJ-A) and NB (NB-A) were performed on days 2 and 3. Improvement following perineural analgesia was measured after 10 min and intra-synovial blocks after 2-, 5- and 10-min. Horses with at least 70% improvement measured objectively after diagnostic analgesia were included in the study. RESULTS: There was no significant association between improvement following perineural analgesia and the DIPJ-A and NB-A. The mean improvement in the lameness differed between DIPJ-A and NB-A at 2 min (p < 0.001) and at 5 min (p = 0.04), and it was no longer observed after 10 min (p = 0.06). A positive NB-A produced a high degree of improvement that remained stable, whereas the DIPJ-A improved over time. MAIN LIMITATIONS: Perineural and intra-synovial analgesia were performed without contrast medium to assess the diffusion of mepivacaine. CONCLUSIONS: Our results suggest that perineural analgesia is not reliable enough to differentiate pain originating from DIPJ and NB. Early evaluation of the DIPJ-A and NB-A can determine the origin of the pain. An improvement following NB-A was constant over time, but an improvement following DIPJ-A varied by up to 10 min.

An Objective Assessment of the Effect of Anesthetizing the Median Nerve on Lameness Caused by Pain in the Cubital Joint.

The median nerve, along with the ulnar nerve, is often anesthetized when performing a lameness examination in horses. Because of the close proximity of the median nerve to the cubital joint, proximal migration of local anesthetic might ameliorate pain originating from the cubital joint. The objective of this study was to determine if a median nerve block will ameliorate lameness caused by pain in the cubital joint. A forelimb lameness was induced in six healthy horses by injecting 100 ng of recombinant equine interleukin 1 beta (IL-1ß) into the cubital joint. The median nerve of the lame leg was anesthetized using 10 mL of 2% mepivacaine hydrochloride. A successful median nerve block was confirmed by loss of skin sensation at the medial aspect of the pastern and typical changes in thermographic images. Gait was assessed before and at 20, 40, and 60 minutes after the median nerve block using an inertial sensor-based motion analysis system (Lameness Locator; Equinosis LLC, Columbia, MO). A full-factorial repeated measures analysis of variance was used to compare treatment effect across time. IL-1ß administration resulted in significant transient lameness in all horses (P < .0001). The median nerve block was successfully performed in all horses and did not result in significant improvement (P = .32) of lameness as quantified by the total differential head vector sum. This result has relevant clinical application as it suggests when performing a lameness examination, it is unlikely that blocking the median nerve with 10 mL of local anesthetic will ameliorate pain originating from the cubital joint.

Objective evaluation versus subjective evaluation of flexion tests in the pelvic limb of horses / Avaliação objetiva versus avaliação subjetiva dos testes de flexão no membro pélvico de cavalos

The agreement between subjective and objective evaluation methods was studied to identify claudication in the pelvic limbs of horses before and after flexion tests were performed. Twenty-nine horses were equipped with a wireless system of inertial sensors and evaluated during seven times while trotting. Videos were recorded to be evaluated by three veterinarians, with different levels of experience, to evaluate the agreement between the two different methods and between the evaluators. The evaluators and the objective evaluation had a low rate of agreement, with the exception of moderate agreement between the objective evaluation and evaluator 1 to identify lameness after the left total flexion and moderate agreement in evaluating the response to the tests, between objective evaluation and evaluator 2, after right distal flexion. This shows that there was a low agreement among the evaluators and between them and the objective evaluation for identifying lameness, measuring the degree of lameness and the response to the flexion tests.(AU)

A concordância entre métodos de avaliação subjetiva e objetiva foi estudada para identificar claudicação nos membros pélvicos antes e após a realização dos testes de flexão. Vinte e nove cavalos foram equipados com um sistema de sensores inerciais sem fio e avaliados durante sete momentos enquanto troteavam. Vídeos foram gravados para serem avaliados por três veterinários com diferentes níveis de experiência, a fim de avaliar a concordância entre os dois métodos diferentes e entre os avaliadores. Os avaliadores e a avaliação objetiva tiveram uma baixa taxa de concordância, com exceção de uma moderada concordância entre avaliação objetiva e avaliador 1 para identificar claudicação após o teste de flexão total esquerdo e uma moderada concordância na avaliação da resposta aos testes, entre avaliação objetiva e avaliador 2, após o teste de flexão distal direito. Isso demonstra que houve uma baixa concordância entre os avaliadores e entre estes e a avaliação objetiva para identificação da claudicação, mensuração do grau de claudicação e resposta aos testes de flexão.(AU)

Impact or push-off lameness presentation is not altered by the type of track surface where horses are trotted / Claudicação de impacto ou elevação não é alterada pelo tipo de superfície onde os cavalos são troteados

This study aimed to evaluate the influence of the track surface on which horses are examined, regarding the phase of lameness presentation. Ten horses with lameness in at least one limb were evaluated with wireless inertial sensors on three track surfaces (concrete, loose sand and grass). Six crossover track sequences were established. The variables vector sum, maximum and minimum height of the head and pelvis, variation coefficient of the maximum and minimum height of the head and pelvis were analyzed using ANOVA, followed by Tukey test to compare means between track surface and sequence, at 5% significance level. The lameness phase (impact or pushoff) was analyzed considering the proportion of affected animals. There were no differences on vector sum, maximum and minimum height or variation coefficient of head and pelvis. Difference was observed on the number of strides registered on sand compared to grass and concrete (p <0.0001) for fore and hindlimbs. Impact lameness on forelimbs was presented by a larger number of animals on the concrete surface; pushoff lameness was more evident on the grass surface. In the hindlimbs, impact lameness was more evident on the grass surface, while pushoff lameness was in greater number of animals on concrete surfaces. The track sequence on which horses were trotted during evaluation does not seem to be a factor, but the number of lame horses and the phase of lameness manifestation can vary between track surfaces, as some horses showed impact lameness on soft ground and elevation lameness on hard ground.

Este estudo teve como objetivo avaliar a influência do tipo de superfície em que os cavalos são examinados em relação à fase de apresentação da claudicação. Dez cavalos com claudicação em pelo menos um dos membros foram avaliados com sensores inerciais sem fio em três tipos de superfície (concreto, areia e grama). Seis sequências de cruzamento de tipo de superfície foram estabelecidas. As variáveis soma vetorial, altura máxima e mínima da cabeça e da pélvis, o coeficiente de variação da altura máxima e mínima da cabeça e da pélvis foram analisadas utilizando uma Análise de Variância, seguida do teste de Tukey para comparação das médias entre tipos de superfície e sequências, a um nível de significância de 5%. A fase da claudicação (impacto ou elevação) foi analisada considerando a proporção de animais afetados. Não houve diferença na soma vetorial, altura máxima ou mínima e coeficiente de variação da altura máxima e mínima da cabeça e pélvis. Foi observada diferença no número de passos registrados na areia em comparação com grama e concreto (p <0,0001) para membros torácicos e pélvicos. Claudicação de impacto nos membros torácicos foi apresentada em um número maior de animais na superfície de concreto, já claudicação de elevação foi mais evidente na superfície de grama. Em membros pélvicos, a claudicação de impacto foi mais evidente na superfície de grama, enquanto claudicação de elevação esteve em maior número de animais na superfície de concreto. A sequência de superfícies em que os cavalos foram troteados durante a avaliação não foi um fator importante na manifestação da claudicação, mas o número de cavalos claudicantes e a fase de manifestação da claudicação podem variar entre as superfícies, visto que alguns cavalos mostraram claudicação de impacto em solo macio e claudicação de elevação em solo duro.