Department of Neurosurgery, Virginia Commonwealth University Health Systems, Medical College of Virginia, Richmond; and.
J Neurosurg Spine. 2015 Jan;22(1):1-10. doi: 10.3171/2014.9.SPINE131005.
Bone allografts used for interbody spinal fusion are often preserved through either freeze drying or lowtemperature freezing, each having disadvantages related to graft preparation time and material properties. In response, a glycerol preservation treatment has been developed to maintain the biomechanical properties of allografts at ambient temperatures, requiring no thawing or rehydration and minimal rinsing prior to implantation. The authors conducted a prospective randomized study to compare the clinical results of glycerol-preserved Cloward dowels and those of freezedried Cloward dowels in anterior cervical discectomy and fusion. The primary outcome measures were evidence of fusion and graft subsidence, and the secondary outcome measures included adverse events, pain, and neck disability scores.
Of 106 patients, 53 (113 levels of surgery) were randomly assigned to the glycerol-preserved graft group and 53 (114 levels of surgery) to the freeze-dried graft group. Subsidence was assessed at 3 and 6 months after implantation. Evidence of fusion was evaluated radiographically at 6 months postimplantation. Subsidence was quantitatively assessed based on physical measurements obtained from radiographs by using calibrated comparators, whereas fusion was also evaluated visually. Surgeons were blinded to treatment type during visual and physical assessments of the patients and the radiographs.
No one in either group had evidence of complete nonunion according to radiographic evaluation at the 6-month follow-up. Average subsidence for all graft-treated levels was 2.11 mm for the glycerol-preserved group and 2.73 mm for the freeze-dried group at the 3-month follow-up and 2.13 and 2.83 mm at the 6-month follow-up, respectively. The 2 treatment groups were statistically equivalent (p = 0.2127 and 0.1705 for the 3- and 6-month follow-up, respectively). No differences were noted between the graft types in terms of adverse event incidence or severity.
Glycerol-preserved bone allografts exhibit fusion results and subsidence values similar to those of their freeze-dried counterparts, potentially more favorable biomechanical properties, and significantly shorter preparation times.
用于脊柱椎间融合的异体骨移植物通常通过冻干或低温冷冻进行保存，这两种方法都存在与移植物准备时间和材料特性相关的缺点。为了应对这一问题，已经开发出甘油保存处理方法，以在环境温度下保持同种异体移植物的生物力学特性，无需解冻或再水化，在植入前只需进行最小程度的冲洗。作者进行了一项前瞻性随机研究，比较甘油保存的 Cloward 栓和冻干的 Cloward 栓在前路颈椎间盘切除和融合术中的临床效果。主要结局指标是融合和移植物下沉的证据，次要结局指标包括不良事件、疼痛和颈部残疾评分。
在 106 例患者中，53 例（113 个手术节段）被随机分配到甘油保存移植物组，53 例（114 个手术节段）分到冻干移植物组。植入后 3 个月和 6 个月评估下沉情况。植入后 6 个月进行影像学评估以确定融合证据。根据校准比较器从 X 光片中获得的物理测量值对下沉进行定量评估，同时还进行视觉评估。在对患者和 X 光片进行视觉和物理评估时，外科医生对治疗类型不知情。
在 6 个月的随访中，根据影像学评估，两组均无人出现完全非融合的证据。甘油保存组所有移植物治疗节段的平均下沉量在 3 个月随访时为 2.11mm，在 6 个月随访时为 2.13mm；冻干组分别为 2.73mm 和 2.83mm。两组在统计学上是等效的（3 个月和 6 个月随访时的 p 值分别为 0.2127 和 0.1705）。在不良事件发生率或严重程度方面，两种移植物类型之间没有差异。
甘油保存的同种异体骨移植物表现出与冻干移植物相似的融合结果和下沉值，可能具有更有利的生物力学特性，并且准备时间显著缩短。
