Análise eletromiográfica e comportamental de equinos submetidos a desmotomia patelar medial

Abstract

The passive support mechanism acts by blocking the flexion of the equine stifle and hock joints, thus preventing muscular fatigue. In cases where this mechanism fails to release during locomotion, the animal may exhibit a condition known as dorsal fixation of the patella, with severe cases requiring medial patellar desmotomy (MPD) as the only treatment. The aim of this study was to investigate possible electrical and behavioral muscle alterations in horses undergoing MPD surgery due to compromised passive support. Five horses with a complaint of dorsal fixation of the patella were deemed suitable for the study. Measurements were taken preoperatively and immediately postoperatively, as well as at 24 hours, 7, 14, and 21 days, using a surface electromyograph. Electrodes were placed bilaterally on the vastus lateralis, tensor fasciae latae, biceps femoris, and semitendinosus muscles for signal capture. Data collection occurred over 60 minutes, and results were analyzed using root mean square (RMS). The preoperative average of tripedal support at rest was 62%. However, postoperatively, the variation in support Exchange and rest was nonexistent. Additionally, a gradual increase in postoperative muscle recruitment was observed. In conclusion, horses undergoing medial patellar desmotomy in this study demonstrated an inability to maintain tripedal support, along with an increased need for muscle fiber recruitment, as evidenced by the gradual rise in electromyographic tracings and total RMS values of the evaluated muscles.