Sekiguchi Ivan, Takeda Naoki, Ishida Naoki
Department of Orthopedic Surgery, Hokuto Medical Corporation Hokuto Hospital, Obihiro, Japan.
Department of Orthopedic Surgery, Sapporo Orthopedic Cardiovascular Hospital, Sapporo, Japan.
Spine Surg Relat Res. 2018 Apr 27;2(4):309-316. doi: 10.22603/ssrr.2018-0002. eCollection 2018 Oct 26.
In an attempt to increase anchoring strength of posterior instrumentation in spine with compromised bone quality, we introduced diagonal trajectory pedicle screwing (hooking screws) that do not rely on screw thread purchase in bone but rather hook onto the strong posterior elements of vertebrae from inside the bone.
Between November 2016 and July 2017 we treated eight patients, mean age 80 years old (75-86 years old) with compromised bone quality for spinal instability. The diagnosis was osteoporotic fracture nonunion in three, ankylosed spine fracture in three, pyogenic spondylitis in two cases. All spines were percutaneously instrumented. Groove-entry technique was used for down-going thoracic screws. No additional hooks, cables, or any other augmentation was used. All patients were mobilized on post-operative day 1.
84 screws were inserted overall. Groove-entry technique was used for 42 screws insertion. On average, 5.3 spinal segments were fixed per case. Mean operation time was 252 min (46 min per one spinal segment). Mean intraoperative bleeding was 112 ml per case (21 ml per one fixed spinal segment). All cases achieved bony union of the fracture site or across the destroyed intervertebral disk. Mean time to union was 4 months postop (3-7 months). All patients were ambulatory at the time of discharge. No nerve injury, no skin irritation caused by implants, no screw loosening, no screw pullout, no loss of correction, and no junctional kyphosis were noted in this series.
Diagonal screw instrumentation (our hooking screws and groove-entry technique) appears to provide sufficient anchoring strength while being minimally invasive and possibly helpful in prevention of junctional kyphosis.
为了增强骨质受损的脊柱后路内固定的锚固强度，我们引入了斜向轨迹椎弓根螺钉固定技术（钩形螺钉），该技术不依赖于螺钉螺纹在骨中的咬合，而是从骨内部钩住椎体的坚固后部结构。
2016年11月至2017年7月，我们治疗了8例骨质受损导致脊柱不稳定的患者，平均年龄80岁（75 - 86岁）。诊断为骨质疏松性骨折不愈合3例，强直性脊柱炎骨折3例，化脓性脊柱炎2例。所有脊柱均采用经皮内固定。下行胸椎螺钉采用开槽置入技术。未使用额外的钩子、缆线或任何其他增强装置。所有患者术后第1天即可活动。
共置入84枚螺钉。42枚螺钉采用开槽置入技术。平均每例固定5.3个脊柱节段。平均手术时间为252分钟（每个脊柱节段46分钟）。平均术中出血量为每例112毫升（每个固定脊柱节段21毫升）。所有病例骨折部位或破坏的椎间盘均实现了骨愈合。平均愈合时间为术后4个月（3 - 7个月）。所有患者出院时均可行走。本系列中未发现神经损伤、植入物引起的皮肤刺激、螺钉松动、螺钉拔出、矫正丢失和交界性后凸畸形。
斜向螺钉内固定技术（我们的钩形螺钉和开槽置入技术）似乎能提供足够的锚固强度，同时具有微创性，可能有助于预防交界性后凸畸形。
