X-Stop (R) Implantation Effectively Limits Segmental Lumbar Extension in-vivo without Altering the Kinematics of the Adjacent Levels

作者：Wan, Zongmiao^*; Li, Guoan

来源：Turkish Neurosurgery, 2015, 25(2): 279-284.

DOI：10.5137/1019-5149.JTN.10135-13.0

• Interspinous process distracting device
• In-vivo
• Kinematics
• Adjacent segments

AIM: To evaluate the in-vivo three-dimensional (3D) vertebral kinematics of the implanted and adjacent segments after implantation of the interspinous process distracting (ISP) device during various functional activities.
MATERIAL and METHODS: Eight patients with lumbar spinal stenosis (LSS) scheduled for X-Stop (R) surgery were recruited. Prior to surgery, patients were scanned with computed tomography/magnetic resonance imaging (CT/MRI) in order to construct 3D L2 to 51 vertebral models. The lumbar spines of the patients were then imaged using two fluoroscopes while they performed seven functional activities before and after X-Stop (R) surgeries. The in-vivo 3D vertebral positions were determined in the dual fluoroscopic images using an established 2D-3D matching method.The vertebral 3D ranges of motion (ROM) of the implanted and cranial-caudal adjacent levels were then measured.
RESULTS: Primary ROMs of the implanted segments were significantly decreased (p<0.05) by 50.2% only at torso extension, from preoperative 2.5 +/- 1.4 degrees to postoperative 1.1 +/- 0.5 degrees, but not significantly (p>0.05) at flexion, twisting and lateral bending. Primary ROM and the coupled translations and rotations of the implanted and the adjacent levels were not significantly changed during each posture.
CONCLUSION: X-Stop (R) implantation reduced the in-vivo range of extension by 50.2% at the implanted segment without disturbing 3D kinematics at the adjacent segments.

• 出版日期2015-3
• 单位南昌大学