通用型脊柱椎弓根内固定系统的研制及临床初步应用

目的　通过对自行设计的通用型脊柱内固定系统 (GSS)进行生物力学测试和初步临床应用 ,评价其效果。方法　采用医用钛合金制成GSS植入物 ,用不锈钢制成专用工具。以新鲜尸体脊柱标本为材料 ,首先进行螺钉拔出试验 ,并分别与CCD ,SOCON ,TSRH和Diapason螺钉进行对比。随后将GSS与SOCON安装于脊柱滑脱标本后进行系统稳定性生物力学测试 ;最后将GSS用于 16例退行性腰椎滑脱不稳患者 ,观察临床疗效。结果　生物力学测试证实GSS与SOCON和CCD比较 ,螺钉最大轴向拔出力分别是 1131N± 2 5 5N、10 34N± 2 6 2N、886N± 15 3N。GSS螺钉拔出力最大 ;系统稳定性与SOCON相似 ;翻修试验结果亦为GSS作用最佳。 16例接受后路GSS手术的患者术后平均随访12 6个月 (11 5～ 14 5个月 ) ,术后 1月及末次随访时X线平片显示滑椎均完全复位 ,所有患者术前临床症状均消失 ,滑脱复位满意且无丢失 ,后外侧植骨融合术后及随访过程中未发现与植入物或手术相关的并发症。结论　GSS独特的螺钉设计 ,可提供坚强的椎体锚固作用和良好的生物力学稳定性 ,用于腰椎滑脱的手术治疗 ,可获得良好的复位效果和临床疗效。

Design and preliminary clinical application of general spine system

OBJECTIVE: To evaluate the efficacy of self-designed General Spine System (GSS) through the measurement of the biomechanical characteristics and the outcomes of preliminary clinical application. METHODS: The General Spine System implants were made of titanium alloy (TC4, Ti6Al4V) and the instruments were made of stainless steel after design. Pull-out strength of GSS screw, CCD, SOCON, TSRH and Diapason screw were tested in fresh normal cadaveric spine specimens respecting and the biomechanical stability analyses of GSS and SOCON were also tested. GSS was applied clinically in 16 patients with degenerative lumbar spondylolisthesis combined with lumbar canal stenosis. Clinical efficacy, reduction effectiveness, and complications were recorded. RESULTS: The pull-out strength of GSS screw was more than other control screws. Biomechanical stability of GSS was similar to SOCON system. Average postoperative follow-up for all patients was 12.6 months (11.5-14.5 months). All patients got satisfied clinical results at the latest follow-up. X-ray results showed complete reduction for all spondylolisthesis patients, and results remained good in follow-up. Complications related to implants or operation were not observed after surgery or in follow-up. CONCLUSION: GSS pedicle screws have strong anchoring ability and good stabilization for spondylolisthesis. This system can provide good reduction for spondylolisthesis. Its clinical efficacy is confirmed.