Application of locking compression plates as type 1 external fixators to treat unilateral mandibular fractures in four equids and one dromedary.

OBJECTIVES: To describe a novel fixation of open, unstable, unilateral mandibular fractures applying a locking compression plate as an external skeletal fixator (ESF-LCP). ANIMALS: Four horses and one dromedary. STUDY DESIGN: Short case series. METHODS: Animals presented with unstable, open, unilateral fractures of the mandible. Fracture fixation was performed under general anesthesia. A 4.5/5.5 narrow LCP was applied externally above the level of the skin and combined with intraoral tension band wiring. RESULTS: Fracture fixation was achieved successfully using an ESF-LCP. Minimal tissue manipulation was required during application and removal of the construct. The ESF-LCPs provided adequate access to the wounds at the fracture site, were well tolerated, and did not interfere with any objects in the animals' environment. Mild drainage at the screw-skin interface developed in all cases, requiring early implant removal due to surgical site infection in one case. The use of longer plates was associated with superficial pressure necrosis of the skin in the masseter area in two cases. Implants were removed after 3 to 12 weeks, and the long-term functional outcome after 11 to 41 (median 13) months was good in all cases. CONCLUSION: Stabilization of mandibular fractures with ESF-LCP led to good outcomes in this case series. The use of longer plates positioned more caudally and in a ventrolateral position seemed associated with surgical site infection and pressure necrosis of the skin. CLINICAL SIGNIFICANCE: Use of a locking compression plate as an external skeletal fixator seems to offer a viable alternative to treat unilateral mandibular fractures, especially when these are open and/or infected.

Single-cut osteotomy for correction of a complex multiplanar deformity of the radius in a Shetland pony foal.

OBJECTIVE: To describe the surgical correction of a multiplanar deformity of the radius in a pony using a single-cut osteotomy. STUDY DESIGN: Case report. ANIMALS: A 9-week-old male Shetland pony foal with a bodyweight of 47 kg. METHODS: The foal presented with a complex multiplanar deformity of the right radius. A 3-dimensional model of the bone was created based on computed tomography (CT) imaging. To correct the deformity, the cutting plane for a single-cut osteotomy was calculated following the mathematical approach described by Sangeorzan et al. After osteotomy, the bone was realigned and stabilized with two 4.5 locking compression plates (LCPs). RESULTS: Recovery from surgery was uneventful, and the foal remained comfortable. A CT exam 15 weeks after surgery revealed that diaphyseal deformities improved substantially in procurvatum (from 8° to 1°), varus (from 27° to 0°), and rotation (30° to 5°). The operated radius was 2.1 cm shorter than the left. Eighteen-month follow up confirmed a functionally and cosmetically acceptable outcome. CONCLUSION: The single-cut osteotomy resulted in the successful correction of a multiplanar equine long-bone deformity with a favorable outcome in a Shetland pony. CLINICAL SIGNIFICANCE: Single-cut osteotomy is an alternative surgical technique for the correction of complex diaphyseal long-bone equine deformities. Computed tomography data and the possibility of printing 3D models provides a significant advantage for rehearsing the procedure and for evaluating the correction that was achieved.

Ex vivo evaluation of an alternative technique for resection of the proximal manica flexoria in horses.

OBJECTIVE: To describe and evaluate an alternative technique for tenoscopic resection of the manica flexoria (MF). STUDY DESIGN: Descriptive study. SAMPLE POPULATION: Equine cadaver forelimbs and hind limbs (n = 36). METHODS: Three surgeons varying in experience resected the MF in 12 limbs. The procedure was divided into six steps, including resection of the lateral/medial borders of the MF with a hook knife and resection of the proximal border with a micro scalpel. Outcomes compared between surgeons included completeness of resection, appearance of the margins of resection, appearance of the resected MF, collateral damage, and time required for resection. RESULTS: The MF was successfully resected in all specimens, with a median time of 14 minutes 54 seconds (range, 6 minutes 42 seconds to 43 minutes 33 seconds). Nineteen of 36 MF were categorized as symmetric, 11 of 36 MF were categorized as mildly asymmetrical, and six of 36 MF had unequal borders. No differences were detected between surgeons regarding the appearance of the MF and number of iatrogenic lesions. Five lesions were considered potentially clinically relevant; three were caused by the arthroscope in the scutum (1) and the deep digital flexor tendon (DDFT; 2), and two consisted of DDFT damage caused by the microscalpel. CONCLUSION: The MF was successfully and symmetrically resected with minimal damage to adjacent structures by surgeons with varying levels of experience. CLINICAL SIGNIFICANCE: The results of this study provide evidence to justify further evaluation of the technique described here in live horses with rupture of the MF.

Internal fixation of a complete ventral luxation of the dens axis in an American quarter horse yearling.

OBJECTIVE: To report surgical treatment of a complete luxation of the atlantoaxial articulation with a 4.5-mm T-locking compression plate (T-LCP) in a horse. STUDY DESIGN: Case report. ANIMALS: A one-year-old American quarter horse filly. METHODS: A one-year-old American quarter horse filly presented with a complete luxation of the atlantoaxial articulation. Closed and open reduction of the luxation were attempted under general anesthesia with the aid of a pulley system. Because the manual reduction was unsuccessful, the dens axis was excised, and the atlas and axis were stabilized with a 4.5-mm T-LCP. Four 5.5-mm cortex screws were placed across the atlantoaxial articulation in lag fashion to provide additional stability. RESULTS: The horse made an uneventful recovery from surgery and remained comfortable thereafter. Nine months postsurgery, the filly had developed normally and did not show any sign of ataxia or reduced mobility of the cranial neck. CONCLUSION: The described surgical approach resulted in the successful stabilization of a complete luxation of the atlantoaxial articulation in an American quarter horse yearling, with a favorable outcome. CLINICAL SIGNIFICANCE: Complete atlantoaxial luxation is associated with a poor prognosis for survival in horses. This is the first report of a favorable outcome after surgical stabilization. The described approach presents a valuable alternative to the manual reduction of atlantoaxial luxation in horses.