Antidegenerative effects of artificial disc replacement by low water content-poly (vinyl alcohol)

虽然一些作者报道了部分椎间盘置换术(PDR)具有良好的临床效果，但很少有对照动物研究证明这种手术的治疗效果。本研究的目的是建立PDR的动物外科模型，并验证其治疗效果。采用放射学和组织学的对照研究方法，对PDR术后兔腰椎间盘的退行性变化进行了体内评价。植入材料为聚乙烯醇水凝胶(含水率为35%)，为棒状。用2.0 mm克氏针刺穿日本大白兔L2/3或L3/4椎间盘，植入内植体。为了进行比较，相邻的椎间盘接受了假处理或对照处理，其中穿透了碟子，但没有植入任何植入物。对30只兔的60个椎间盘在术后1、3、6个月进行放射学和组织学退行性改变分析。放射学分析显示，与对照治疗相比，替代治疗明显减少了椎间高度的损失。置换治疗后椎间高度的变化与假治疗后无显著差异。与对照相比，替换的椎间盘的组织学退变延迟，但随着时间的推移而进展。即使使用含水量较高的种植体，在组织学上也没有观察到明显的形状变化。本研究建立了一种安全、重复性好的PDR动物模型，并通过定量放射学和组织学分析证实了其抗退变作用。通过保留椎间高度和占用NP间隙，延缓了替代治疗后房颤的退变。适当的材料选择和植入物的设计对于长期的成功是必要的。

Although some authors reported that partial disc replacements (PDR) have beneficial clinical outcomes, there are few controlled animal studies in which the therapeutic effects of this procedure have been demonstrated. The objective of this study was to establish an animal surgery model of PDR and to demonstrate its therapeutic effects. In vivo degenerative changes of rabbit intervertebral discs after PDR were evaluated radiologically and histologically in a controlled trial. The implants were made of poly (vinyl alcohol) hydrogel (35% water content) and rod-shaped. The L2/3 or L3/4 intervertebral discs of Japanese white rabbits were pierced with a 2.0 mm Kirschner wire and implants were inserted into the holes. For comparative purposes, the adjacent discs underwent sham treatments or control treatments in which the dish was pierced but no implant was inserted. Sixty discs from 30 rabbits were analyzed radiologically and histologically for degenerative changes at 1, 3, or 6 months postoperatively. Radiological analysis revealed that significantly less disc height was lost with the replacement treatment than with the control treatment. Change in disc height after the replacement treatment was not significantly different from that after the sham treatment. Histological degeneration of the replaced discs was delayed in comparison with that of the control discs but progressed with time. Even when implants with higher water content were used, no remarkable change was histologically observed in shape. In this study, a safe and reproducible animal model of PDR was established, and its antidegenerative effects were demonstrated by quantitative radiological and histological analyses. Degeneration of the AF after the replacement treatment was delayed by preserving disc height and occupying the NP space. Proper selection of material and design of implants are necessary for long-term success.