Investigative study of Spinal Instrumentation utilizing PLLA (Poly-L-lactide)

利用 PLLA（聚左旋丙交酯）进行脊柱器械的调查研究

• 批准号: 08671630
• 负责人: SHONO Yasuhiro
• 金额: $ 1.47万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08671630/
• 关键词: SPINAL INSTRUMENTATION; PLLA (Poly-L-lactide); SPINAL FUSION; BIOMECHANICS; ポリ-L乳酸骨接合材; 力学試験; 生体力学試験

Biomechanical and clinical studies were performed to evaluate the stability and the influence of spinal instrumentation on the residual intact motion segments using spinal fracture and deformity models. Conventional rigid metal based spinal instrumentation provided effective satiability to the spine in both fracture and deformity modeles. However, as the rigidity of the instrumentation increased stress on the adjacent intact motion segments significantly increased. Also, spinal instrumentation changes the motion pattern of the residual motion segments, and the changes in the motion pattern become more distinct as the rigidity of the fixation increases. To overcome these negative effects of the conventional metal based instrumentation, new spinal instrumentation consists of metal screws and PLLA rod was developed for experimental investigation. Spinal fusion using PLLA instrumentation was performed in lumber spine of the 12 sheep. Total 24 spinal segments were fused. After four to six months, lumbar motion segments were sacrificed Although PLLA dissolves in the living body, extracted PLLA rods showed no evidence of dissolution. To make PLLA implant stable enough to withstand the load which spine must endure, dissolution ability of the PLLA will be sacrificed. At present technology, PLLA instrumentation which has enough stability to reconstruct the spine and, also, dissolution characteristic to allow effective fusion of the spinal segments is difficult to develop. Further research is required to develop new system. In clinical situation, the authors used PLLA screw for fixation of the bone graft to the graft site in reconstruction of the cervical spine disorders. We have analyzed more than 30 parents who underwent cervical fusion surrey. All patients obtained solid fusion and showed better clinical results compared to only graft without PLLA screw fixation.

使用脊柱骨折和畸形模型进行生物力学和临床研究，以评估脊柱内固定对剩余完整运动节段的稳定性和影响。传统的刚性金属脊柱内固定在骨折和畸形模型中提供了有效的脊柱满足度。然而，随着内固定刚度的增加，相邻完整运动节段的应力显著增加。此外，脊柱内固定改变了剩余运动节段的运动模式，并且随着固定物刚性的增加，运动模式的变化变得更加明显。为了克服传统金属基内固定的这些负面影响，开发了由金属螺钉和PLLA棒组成的新型脊柱内固定进行实验研究。采用PLLA器械对12只羊的腰椎进行脊柱融合术。共融合24个脊柱节段。4 ~ 6个月后，切除腰椎活动节段，尽管PLLA在活体中溶解，但提取的PLLA棒没有溶解的迹象。为了使PLLA植入物能够稳定地承受脊柱必须承受的载荷，牺牲了PLLA的溶解能力。在目前的技术条件下，很难开发出具有足够稳定性来重建脊柱的PLLA内固定装置，同时又具有溶解特性以使脊柱节段有效融合。开发新系统需要进一步的研究。临床应用PLLA螺钉将植骨固定于植骨部位，用于颈椎疾患的重建。我们分析了30多名接受颈椎融合检查的父母。所有患者均获得了牢固的融合，与仅植骨不加PLLA螺钉固定相比，临床效果更好。

项目成果

SHONO, Yasuhiro: "Stability of Posterior Spinal Instrumentation and Its Effects on Adjacent Motion Segments in the Lumbosacral Spine" Spine. 23・14. 1550-1558 (1998)

SHONO，Yasuhiro：“后脊柱器械的稳定性及其对腰骶脊柱相邻运动节段的影响” 脊柱 23・14（1998）。

庄野 泰弘: "4.New Mook 整形外科 : 脊椎・脊髄損傷" 金原出版株式会社, 227 (1998)

庄野泰宏：《4.新穆克骨科：脊柱/脊髓损伤》金原出版有限公司，227（1998）