Development of an intervertebral disc prosthesis prototype for the canine cervical spine

ABSTRACT: Cervical arthroplasty with disc prosthesis has been proposed as a treatment option for dogs with Cervical Spondylomyelopathy. The present study developed a novel vertebral disc prosthesis for dogs. Sixteen Functional Spinal Units (C5-C6) were collected from dog cadavers with body weights ranging between 25 and 35 kg, and their vertebral measurements were used to design a prosthetic disc. The sizing of the prosthesis was performed based on the averages of the measurements of width, height, and length of the vertebral bodies from C5-C6 of all specimens. The prosthesis was developed using the Rhinoceros 3D® and SolidWorks® programs, and 3D prototyping was carried out to define the best design. The developed prosthesis consisted of two independent parts that are fixed to the cranial and caudal vertebral bodies, in the intervertebral space, and fitted together by metal-to-metal surfaces capable of moving in the lateral, ventral, and dorsal directions. Each part of the prosthesis is angled in two portions: vertically, in the intervertebral space, and horizontally, in contact with the ventral surface of the vertebral bodies, both of which are fixed by means of monocortical locking screws. The design of the developed prototype allowed a good fit in the intervertebral space between C4-C5, C5-C6, and C6-C7.

摘要：针对患有颈椎脊髓病（Cervical Spondylomyelopathy）的犬只，采用椎间盘假体的颈椎关节成形术已被提出作为一种治疗方案。本研究研发了一款新型犬用椎间盘假体。研究从体重介于25~35 kg的犬尸体中获取16个功能脊柱单元（Functional Spinal Units，C5-C6节段），通过测量其椎体参数开展假体设计。假体的尺寸基于所有标本C5-C6节段椎体的宽度、高度及长度的平均值进行设计。研究依托Rhinoceros 3D®与SolidWorks®软件完成假体开发，并通过3D原型制作确定最优设计方案。所研发的假体包含两个独立部件，分别固定于椎间间隙的头侧与尾侧椎体，二者通过金属-金属接触面契合，可实现侧向、腹侧及背侧的运动。假体的每个部件均分为两个倾斜结构：其一为适配椎间间隙的垂直结构，其二为与椎体腹侧表面贴合的水平结构，二者均通过单皮质锁定螺钉实现固定。所开发的原型可良好适配C4-C5、C5-C6及C6-C7节段的椎间间隙。