Dorsal-to-palmar branch neuroanastomosis in horses undergoing palmar digital neurectomy does not reduce neuroma formation or improve outcome.

OBJECTIVE: Chronic foot pain, a common cause of forelimb lameness, can be treated by palmar digital neurectomy (PDN). Complications include neuroma formation and lameness recurrence. In humans, neuroanastomoses are performed to prevent neuroma formation. The aim of the study was to evaluate the outcome of horses undergoing dorsal-to-palmar branch neuroanastomosis following PDN. STUDY DESIGN: Retrospective case series. ANIMALS: Eighty-five horses with PDN and dorsal-to-palmar branch neuroanastomosis. METHODS: Medical records for horses undergoing this procedure at two hospitals between 2015 and 2020 were reviewed. Palmar and dorsal nerve branches of the PDN were transected and end-to-end neuroanastomosis was performed by apposition of the perineurium. Follow-up was obtained from medical records and telephone interviews. Success was defined as resolution of lameness for at least one year. RESULTS: Lameness resolved following surgery in 81/85 (95%) horses with 57/84 (68%) sound at one year. Postoperative complications occurred in 19/85 (22%) cases. The main limitations of the study were an incomplete data set, inaccurate owner recall, and variations in procedure. CONCLUSION: Compared to previous studies, this technique resulted in similar numbers of horses sound immediately after surgery, a comparable rate of postoperative neuroma formation but a higher recurrence of lameness rate at 1 year postoperatively. CLINICAL SIGNIFICANCE: End-to-end neuroanastomosis of the dorsal and palmar branches of the PDN does not reduce the rate of neuroma formation in horses. Long-term outcome was less favorable compared to previously reported PDN techniques.

Application accuracy of a frameless optical neuronavigation system as a guide for craniotomies in dogs.

BACKGROUND: Optical neuronavigation systems using infrared light to create a virtual reality image of the brain allow the surgeon to track instruments in real time. Due to the high vulnerability of the brain, neurosurgical interventions must be performed with a high precision. The aim of the experimental cadaveric study was to determine the application accuracy of a frameless optical neuronavigation system as guide for craniotomies by determining the target point deviation of predefined target points at the skull surface in the area of access to the cerebrum, cerebellum and the pituitary fossa. On each of the five canine cadaver heads ten target points were marked in a preoperative computed tomography (CT) scan. These target points were found on the cadaver skulls using the optical neuronavigation system. Then a small drill hole (1.5 mm) was drilled at these points. Subsequently, another CT scan was made. Both CT data sets were fused into the neuronavigation software, and the actual target point coordinates were identified. The target point deviation was determined as the difference between the planned and drilled target point coordinates. The calculated deviation was compared between two observers. RESULTS: The analysis of the target point accuracies of all dogs in both observers taken together showed a median target point deviation of 1.57 mm (range: 0.42 to 5.14 mm). No significant differences were found between the observers or the different areas of target regions. CONCLUSION: The application accuracy of the described system is similar to the accuracy of other optical neuronavigation systems previously described in veterinary medicine, in which mean values of 1.79 to 4.3 mm and median target point deviations of 0.79 to 3.53 mm were determined.

Placement of vertebral screws for spinal stabilization and distraction in a dog with disc-associate cervical spondylomyelopathy: case report / Uso de parafusos vertebrais para distração e estabilização espinhal em um cão com espondilomielopatia cervical disco-associada: relato de caso

A 10-year-old male Rottweiler was evaluated for a 2-month history of recurrent forelimb weakness. Neurologic examination revealed proprioceptive ataxia, tetraparesis and moderate cervical pain. Disk-associated cervical spondylomyelopathy (CSM) with static lesion at C3-4 was diagnosed based on magnetic resonance imaging (MRI). The dog was surgically treated by a ventral slot procedure and distraction-stabilization of the vertebral bodies through insertion of vertebral screws with transverse connective bars. The patient had favorable clinical outcome. Neurologic assessment performed 120 days after surgery showed absence of neurologic defects. Radiographic assessment performed at the same time indicated adequate spinal cord decompression although vertebral fusion was not achieved. To the authors' knowledge, this is the first case of distraction-stabilization with vertebral (pedicle) screws to treat CSM in a dog. The treatment was well tolerated with no complications and excellent outcome and can be a viable option for this condition.(AU)

Um cão, macho, adulto, Rotweiller de 10 anos de idade, foi atendido com histórico de claudicação do membro torácico esquerdo com evolução para fraqueza havia aproximadamente dois meses. Ao exame neurológico, observou-se ataxia proprioceptiva nos quatro membros e dor cervical moderada. Mediante ressonância magnética, espondilomielopatia cervical disco-associada com a característica estática da compressão C3-C4 foi diagnosticada. Realizou-se cirurgia descompressiva por meio de slot ventral e estabilização-distração com o uso de parafusos vertebrais e barras conectoras. O paciente apresentou evolução clínica favorável do quadro. A evolução foi progressiva e, no último retorno, 120 dias após a cirurgia, não apresentou nenhum déficit neurológico ou sinal de falha do implante nas imagens radiográficas; no entanto, não foi evidenciada fusão vertebral. Pelo conhecimento dos autores, esse é o primeiro relato de EMC disco-associada tratada por distração e estabilização com parafusos vertebrais (pediculares) em um cão. A fixação espinhal por meio do uso de parafusos vertebrais foi uma alternativa viável no caso apresentado.(AU)

Comparison of palmar digital neurectomy by the guillotine technique and palmar digital neurotomy associated with end-to-side neurorrhaphy in mares / Comparação entre neurectomia por técnica de guilhotina e neurotomia associada à neurorrafia em alça de balde em nervo digital palmar de éguas

Five mares were submitted to palmar digital neurectomy by the guillotine technique and palmar digital neurotomy followed by end-to-side neurorrhaphy (right and left thoracic limbs, respectively). Mares were checked for local pain sensation using hoof tester and submitted to lameness workup at 15-day intervals. No evidence of painful neuroma formation was detected. Palmar digital nerve (PDN) stump segments were collected within 60 days of surgery. Mean left and right limb PDN stump thickness corresponded to 5.96 mm and 7.16 mm, respectively. Schwann cells prevailed over connective healing tissue in all PDN stumps studied. Well-formed nerve-like structures with better organized nervous tissue and predominance of parallel nerve fiber orientation were documented in left limb PDN stumps. End-to-side neurorrhaphy tended to promote tissue organization, potentially reducing the chances of neuroma formation...

O nervo digital palmar (NDP) lateral do membro torácico direito (MTD) de cinco equinos fêmeas foi submetido à neurectomia pela técnica da guilhotina, e o do membro torácico esquerdo (MTE) à neurotomia e neurorrafia término-lateral. Os animais foram avaliados a cada 15 dias quanto ao teste de sensibilidade cutânea com pressão local com pinça de casco e de claudicação, não sendo notados sinais clínicos de neuroma doloroso. Aos 60 dias pós-cirurgia coletou-se segmentos dos cotos proximais dos NDPs. Os dos MTDs apresentavam em média, a espessura de 7,16 mm e aos dos MTEs de 5,96 mm. Nos cotos proximais dos nervos dos membros direito e esquerdo notou-se predominância de células de Schwann à grande quantidade de tecido conjuntivo cicatricial. Os do MTEs apresentavam estruturas de nervo típico, bem constituídas, com maior organização do tecido nervoso e predomínio de fibras nervosas orientadas paralelamente. A neurorrafia termino-lateral apresentou tendência a ocasionar maior organização entre as estruturas analisadas, o que lhe conferiu menor potencial em desenvolver neuromas dolorosos...

Traumatismo encefálico con fractura de cráneo. Tratamiento médico y quirúrgico. Reporte de un caso / Head trauma with a skull fracture. Medical and surgery assessment. Case Report

Se presenta al Consultorio Veterinario de la Universidad de Antioquia una perra de raza Pinsher miniatura de 6 años, con convulsiones tónico clónicas y en estado de delirio, después de sufrir un fuerte traumatismo ocasionado por el ataque de otro perro. A la exploración física se detecta una fractura en el cráneo, que luego fue confirmada por radiología. Se instaura tratamiento médico encaminado a reducir la presión intracraneal. Al no mejorar neurológicamente se somete a cirugía. Este procedimiento permitió la mejoría del paciente y la posterior recuperación total de los síntomas neurológicos, sin que hasta la fecha se hayan presentado secuelas del incidente.