Biomechanical testing of three constructs for prosthetic laryngoplasty in horses demonstrates advantages of differing metallic implants in the arytenoid cartilage.

Objective: To compare the biomechanical stability of a novel arytenoid implant (tie-bolt, TB) with a suture anchor (SA) and standard laryngoplasty using suture alone (control) in equine larynges.

Study Design: Randomized ex vivo controlled experimental study.

Sample Population: Thirty equine cadaver larynges.

Equine laryngoplasty: Effects of three anchoring techniques in the muscular process and three positions for suture implantation in the cricoid cartilage.

Objective: To compare the effects of three anchoring techniques in the muscular process and three positions of laryngoplasty suture implantation in the cricoid cartilage on abduction of the arytenoid cartilage and interaction with the cricoarytenoid dorsalis (CAD) muscle compartments.

Study Design: Experimental study.

Sample Population: Twenty-two cadaveric equine larynges.

Decreasing polymethyl methacrylate bone cement concentration extends working and setting times in vitro.

Objective: To determine setting and temperature properties of diluted polymethyl methacrylate (PMMA) bone cement in vitro to assess utility for vocal fold augmentation in horses.

Samples: 4 dilutions of PMMA equivalent to volumes of 15 mL, 20 mL, 25 mL, and 30 mL PMMA powder (PMMAp) in 10 mL solvent.

Methods: For each volume PMMAp, setting times (tset), peak temperatures (Tmax), and times to peak temperature (tmax) were determined using a temperature data logger in a 4-mL volume of PMMA.

Clinical and Pathological Features in Horses With Advanced Arytenoid Chondritis.

Equine arytenoid chondritis causes airway obstruction and abnormal upper airway noise due to a space-occupying lesion(s) and decreased abduction. Our objective was to compare clinical scores and ultrasonographic findings with gross and microscopic lesions of naturally occurring arytenoid chondritis, in order to guide surgical treatment. Seventeen naturally affected horses with advanced/severe chronic arytenoid chondritis and 4 control arytenoid cartilages were evaluated after partial arytenoidectomy.

Equine Nasal Endoscopy: Treating Bullae Disease and Sinus Disease.

The nasal conchal bullae (dorsal and ventral) are separate, air-filled structures within their respective dorsal and ventral nasal conchae. Computed tomography scans have assisted with the increasing diagnosis of empyema of the nasal conchae. This condition is usually associated with dental or sinus disease.

An Exploratory Study into the Implantation of Arytenoid Cartilage Scaffold in the Horse.

Respiratory function in the horse can be severely compromised by arytenoid chondritis, or arytenoid chondropathy, a pathologic condition leading to deformity and dysfunction of the affected cartilage. Current treatment in cases unresponsive to medical management is removal of the cartilage, which can improve the airway obstruction, but predisposes the patient to other complications like tracheal penetration of oropharyngeal content and dynamic collapse of the now unsupported soft tissue lateral to the cartilage. A tissue engineering approach to reconstructing the arytenoid cartilage would represent a significant advantage in the management of arytenoid chondritis.

Management of postoperative dysphagia after prosthetic laryngoplasty or arytenoidectomy.

Objective: To evaluate the efficacy of various treatments for dysphagia after laryngeal surgery.

Study Design: Retrospective.

Animals: Horses treated for dysphagia after laryngeal surgery.

Joint Sepsis and Osteomyelitis Is Associated With a Grave Prognosis in Foals.

The most common pathologic manifestation of , a gram-positive, facultative intracellular bacterium, is pyogranulomatous pneumonia in foals and weanlings. Hematogenous spread of bacteria may subsequently occur, resulting in joint sepsis, osteomyelitis, or subcutaneous abscessation. Medical records from horses presenting to the Cornell University Equine Hospital from 1998 to 2018 were reviewed for cases diagnosed with joint and/or bone infection, and information about case progression and outcome were analyzed.

Investigation into pathophysiology of naturally occurring palatal instability and intermittent dorsal displacement of the soft palate (DDSP) in racehorses: Thyro-hyoid muscles fatigue during exercise.

Exercise induced intermittent dorsal displacement of the soft palate (DDSP) is a common cause of airway obstruction and poor performance in racehorses. The definite etiology is still unclear, but through an experimental model, a role in the development of this condition was identified in the dysfunction of the thyro-hyoid muscles. The present study aimed to elucidate the nature of this dysfunction by investigating the spontaneous response to exercise of the thyro-hyoid muscles in racehorses with naturally occurring DDSP.

Transendoscopic correction of epiglottic entrapment with a silicone-covered laser guide and diode laser in 29 horses.

Objective: To describe the use of a silicone-covered laser guide and diode laser for surgical correction of epiglottic entrapment and report postoperative outcomes in horses with epiglottic entrapment.

Study Design: Retrospective case series.

Animals: Thoroughbred and standardbred racehorses (n = 29) with epiglottic entrapment.

Return to racing after surgical management of third carpal bone slab fractures in thoroughbred and standardbred racehorses.

Objective: To determine the prognosis for racing of horses surgically treated for slab fractures of the third carpal bone (C3).

Study Design: Retrospective case study.

Animals: Horses (n = 125) surgically treated for C3 slab fractures.

Functional electrical stimulation following nerve injury in a large animal model.

Introduction: Controversy exists over the effects of functional electrical stimulation (FES) on reinnervation. We hypothesized that intramuscular FES would not delay reinnervation after recurrent laryngeal nerve (RLn) axonotmesis.

Methods: RLn cryo-injury and electrode implantation in ipsilateral posterior cricoarytenoid muscle (PCA) were performed in horses.

Asymmetric recurrent laryngeal nerve conduction velocities and dorsal cricoarytenoid muscle electromyographic characteristics in clinically normal horses.

The dorsal cricoarytenoid (DCA) muscles, are a fundamental component of the athletic horse's respiratory system: as the sole abductors of the airways, they maintain the size of the rima glottis which is essential for enabling maximal air intake during intense exercise. Dysfunction of the DCA muscle leads to arytenoid collapse during exercise, resulting in poor performance. An electrodiagnostic study including electromyography of the dorsal cricoarytenoid muscles and conduction velocity testing of the innervating recurrent laryngeal nerves (RLn) was conducted in horses with normal laryngeal function.

Transnasal, Endoscopically Guided Skull-Based Surgery by Pharyngotomy for Mass Removal from the Sphenopalatine Sinus in a Horse.

Objective: To report a transnasal, endoscopically guided ventral surgical approach for accessing the cranial and caudal segments of the sphenopalatine sinus for mass removal in a horse.

Study Design: Case report.

Animal: Adult horse with acute onset blindness referable to a soft tissue mass within the sphenopalatine sinus.

Effects of Functional Electrical Stimulation on Denervated Laryngeal Muscle in a Large Animal Model.

Bilateral vocal fold paralysis (BVCP) is a life-threatening condition that follows injury to the Recurrent Laryngeal nerve (RLn) and denervation of the intrinsic laryngeal musculature. Functional electrical stimulation (FES) enables restoration and control of a wide variety of motor functions impaired by lower motor neuron lesions. Here we evaluate the effects of FES on the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle in a large animal model of RLn injury.

Ultrasonography detects early laryngeal muscle atrophy in an equine neurectomy model.

Introduction: A unilateral neurectomy model was used to study the relationship between histologic and ultrasonographic tissue characteristics during muscle atrophy over time.

Methods: This investigation was an in vivo experimental study in an equine model (n = 28). Mean pixel intensity of ultrasonographic images was measured, a muscle appearance grade was assigned weekly, and muscles were harvested from 4 to 32 weeks.

Laryngoplasty in standing horses.

Objective: To describe the clinical experience with standing laryngoplasty in a series of horses mostly nonracing.

Study Design: Case series.

Animals: Seventy-one client-owned horses.

Computed tomography-guided tissue engineering of upper airway cartilage.

Normal laryngeal function has a large impact on quality of life, and dysfunction can be life threatening. In general, airway obstructions arise from a reduction in neuromuscular function or a decrease in mechanical stiffness of the structures of the upper airway. These reductions decrease the ability of the airway to resist inspiratory or expiratory pressures, causing laryngeal collapse.

Regenerative medicine approach to reconstruction of the equine upper airway.

Airway obstruction is a common cause of poor performance in horses. Structural abnormalities (insufficient length, rigidity) can be a cause for the obstruction. Currently, there are a few effective clinical options for reconstruction of the equine larynx.

Effects of hypoglossal nerve block and electrical stimulation of the thyrohyoideus muscles on position of the larynx and hyoid apparatus in healthy horses.

Objective: To determine the effects of hypoglossal nerve block and electrical stimulation of the thyrohyoideus muscles on position of the larynx and hyoid apparatus in resting horses.

Animals: 16 healthy horses that underwent hypoglossal nerve block and 5 healthy horses that underwent electrical stimulation of the thyrohyoideus muscles.

Procedures: Horses underwent bilateral hypoglossal nerve block or electrical stimulation of the thyrohyoideus muscles.

Functional electrical stimulation of intrinsic laryngeal muscles under varying loads in exercising horses.

Bilateral vocal fold paralysis (BVCP) is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES). Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP.

A transducer for measuring force on surgical sutures.

The objective of this study was to validate, both in vitro and in an ex vivo model, a technique for the measurement of forces exerted on surgical sutures. For this purpose, a stainless steel E-type buckle force transducer was designed and constructed. A strain gauge was mounted on the central beam of the transducer to measure transducer deformation.

Equine laryngoplasty sutures undergo increased loading during coughing and swallowing.

Objectives: To report (1) the force required on a single laryngoplasty suture to achieve optimal abduction of the left arytenoid cartilage, (2) peak forces experienced by the suture during induced swallowing and coughing, and during 24-hour resting activity in a stall, and (3) peak forces during induced swallowing and coughing after left recurrent laryngeal nerve blockade.

Study Design: Experimental study.

Animals: Horses (n=8).

A technique for laser-facilitated equine pastern arthrodesis using parallel screws inserted in lag fashion.

Objective: To report a technique for laser-facilitated, minimally invasive proximal interphalangeal joint (PIJ) arthrodesis in horses.

Study Design: Case series.

Animals: Horses (n=6); 5 thoracic and 2 pelvic limb PIJ.