Comparative Stiffness of an Equine Distal Sesamoid Bone Fracture Model Stabilized with 3.5-mm versus 4.5-mm Cortical Bone Screws in Lag Fashion.

OBJECTIVE: The aim of this study was to to determine the comparative stiffness following repair of an axial sagittal fracture model in equine distal sesamoid bones using either a single 3.5-mm or 4.5-mm cortical bone screw placed in lag fashion. STUDY DESIGN: The present study was an in vitro biomechanical study. RESULTS: The mean (±standard deviation) stiffness value for the 4.5-mm screw-bone construct (522.49 N/mm ± 168.21) was significantly greater than the 3.5-mm screw-bone construct (408.46 N/mm ± 131.13) (p = 0.047). This represents a 28% difference in mean stiffness. CONCLUSIONS: In vitro, the 4.5-mm screw-bone construct creates a stiffer repair of fractured distal sesamoid bones by a margin of 28%. The 4.5-mm cortical bone screw may better withstand forces imparted on the distal sesamoid bone sustained during anaesthetic recovery, normal weight bearing and athletic exercise, thereby minimizing the risk of implant failure.

Adaptation and evaluation of a monopolar electrosurgical triangle-tip knife for transendoscopic ventriculocordectomy in healthy horses.

OBJECTIVE: To evaluate the efficacy and safety of a transendoscopic monopolar electrosurgical triangle-tip knife as instrumentation to perform unilateral ventriculocordectomy (VC) in healthy adult horses. STUDY DESIGN: In vivo experimental study. STUDY POPULATION: Nine horses donated for medical conditions unrelated to respiratory system. METHODS: The triangle-tip knife was applied in contact fashion. Left VC was performed under standing sedation. Endoscopic images of the upper airway were graded for inflammation by 2 masked surgeons preoperatively and immediately, 24 hours and, in 2 cases, 7 and 14 days postoperatively. Four larynxes were examined for histological evidence of inflammation and collagen deposition at 24 hours (n = 2) and at 14 days (n = 2) after surgery. RESULTS: Ventriculocordectomy was successfully performed in all horses. Endoscopic evidence of inflammation was scored as normal (preoperatively), mild (immediately postoperatively), mild (24 hours postoperatively), mild (7 days postoperatively), and normal (14 days postoperatively). According to histopathology, inflammation of the surgical site and ventricularis muscle was generally increased (variable is common and is present in most high-power fields) 24 hours and 14 days postoperatively. Fibrosis and collagen deposition also seemed increased at the surgical site 14 days postoperatively. CONCLUSION: Ventriculocordectomy was successfully performed with an electrosurgical triangle-tip knife and resulted in acceptable short-term outcomes. CLINICAL SIGNIFICANCE: The use of an electrosurgical triangle-tip knife alternative instrumentation may be offer an alternative option to perform VC in practices when diode laser is not available or is cost prohibitive. Longer term evaluation of the VC site is required to determine the effect on rima glottic cross-sectional area.

Tenotomy of the semitendinosus muscle under standing sedation versus general anesthesia: Outcomes in 20 horses with fibrotic myopathy.

OBJECTIVE: To compare outcomes after semitendinosus tenotomy performed under standing sedation versus general anesthesia. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: 20 horses with fibrotic myopathy of the semitendinosus muscle. METHODS: Medical records (2002-2015) of horses undergoing tenotomy of the semitendinosus muscle for the treatment of fibrotic myopathy were reviewed. Signalment, history, affected muscles, restrain method, surgical procedures, and short-term outcome as well as complications were retrieved from records. Long-term outcome (gait and athletic function) was assessed at least 6 months postoperatively by conversation with the owners. Pearson's χ2 statistical analysis was used to compare restrain method and affected muscles with overall outcome. Significance was set at P < .05. RESULTS: Tenotomy of the semitendinosus muscle was performed under standing sedation in 8 horses and under general anesthesia in 12 horses. Follow-up period ranged from 9 months to 10 years. Gait was improved to variable degrees in 8 of 14 horses when the semitendinosus muscle alone was affected and in 4 of 6 horses when both the semitendinosus and semimembranosus muscles were involved (P = .11). Six of 8 horses treated under standing sedation and 6 of 12 horses treated under general anesthesia exhibited some improvement in the characteristic fibrotic gait (P = .4473). Five of 6 athletic horses treated under standing sedation and 6 of 9 athletic horses treated under general anesthesia returned to their preinjury level of athleticism. Horses treated under standing sedation had no incisional complications; 2 of 12 horses treated under general anesthesia exhibited incisional drainage. CONCLUSION: Tenotomy of the semitendinosus muscle in horses with fibrotic myopathy leads to similar improvement in gait, whether performed under standing sedation or general anesthesia.