Park Soo-An, Fayyazi Amir H, Yonemura Kenneth S, Fredrickson Bruce E, Ordway Nathaniel R
Spine Center, Seoul St Mary's Hospital, The Catholic University of Korea, College of Medicine, Seoul, South Korea.
VSAS Orthopaedics, Institute for Advanced Healthcare, Allentown, PA.
Int J Spine Surg. 2012 Dec 1;6:87-92. doi: 10.1016/j.ijsp.2012.02.003. eCollection 2012.
Biomechanical studies have shown that dynamic stabilization restores the neutral zone and stabilizes the motion segment. Unfortunately, there are limitations to clinical measurement of lumbar motion segments when using routine radiographs. Radiostereometric analysis is a 3-dimensional technique and can measure the spinal motion segment more accurately than techniques using plain film radiographs. The purpose of this study was measure and compare the range of motion after dynamic stabilization, posterior lumbar fusion (PLF), and lumbar discectomy.
Four patients who underwent lumbar decompression and dynamic stabilization (Dynesys; Zimmer Spine, Inc., Warsaw, Indiana) for treatment of lumbar spondylosis were compared with 4 patients with a similar diagnosis who were treated by PLF and pedicle screw fixation (PLF group) and 8 patients who had undergone lumbar microdiscectomy (discectomy group) for treatment of radiculopathy. During the surgical procedure, 3 to 5 tantalum beads were placed into each of the operative segments. The patients were followed up postoperatively at 1 month, 1 year, and 2 years. At each follow-up time point, segmental motions (flexion, extension, and total sagittal range of motion [SROM]) were measured by radiostereometric analysis.
Flexion, extension, and SROM measured 1.0° ± 0.9°, 1.5° ± 1.3°, and 2.3° ± 1.2°, respectively, in the Dynesys group; 1.0° ± 0.6°, 1.1° ± 0.9°, and 1.5° ± 0.6°, respectively, in the PLF group; and 2.9° ± 2.4°, 2.3° ± 1.5°, and 4.7° ± 2.2°, respectively, in the discectomy group. No significant difference in motion was seen between the Dynesys and PLF groups or between the Dynesys and discectomy groups in extension. Significant differences in motions were seen between the PLF and discectomy groups and between the Dynesys and discectomy groups in flexion (P = .007) and SROM (P = .002). There was no significant change in the measured motions over time.
In this study a significantly lower amount of motion was seen after dynamic stabilization and PLF when compared with discectomy. A future study with a larger cohort is necessary to examine what effect, if any, these motions have on clinical outcomes.
生物力学研究表明，动态稳定化可恢复中性区并稳定运动节段。遗憾的是，使用常规X线片对腰椎运动节段进行临床测量存在局限性。放射立体测量分析是一种三维技术，与使用普通X线片的技术相比，能更准确地测量脊柱运动节段。本研究的目的是测量并比较动态稳定化、腰椎后路融合术（PLF）和腰椎间盘切除术后的活动范围。
将4例因腰椎退变性疾病接受腰椎减压及动态稳定化治疗（Dynesys；齐默脊柱公司，印第安纳州华沙）的患者，与4例诊断相似且接受PLF及椎弓根螺钉固定治疗的患者（PLF组）以及8例因神经根病接受腰椎显微椎间盘切除术的患者（椎间盘切除术组）进行比较。在手术过程中，向每个手术节段植入3至5颗钽珠。术后对患者进行1个月、1年和2年的随访。在每个随访时间点，通过放射立体测量分析测量节段运动（前屈、后伸和矢状面总活动范围[SROM]）。
Dynesys组的前屈、后伸和SROM分别为1.0°±0.9°、1.5°±1.3°和2.3°±1.2°；PLF组分别为1.0°±0.6°、1.1°±0.9°和1.5°±0.6°；椎间盘切除术组分别为2.9°±2.4°、2.3°±1.5°和4.7°±2.2°。Dynesys组与PLF组之间以及Dynesys组与椎间盘切除术组之间在后伸时的运动无显著差异。PLF组与椎间盘切除术组之间以及Dynesys组与椎间盘切除术组之间在前屈（P = .007）和SROM（P = .002）方面存在显著差异。测量的运动随时间无显著变化。
在本研究中，与椎间盘切除术相比，动态稳定化和PLF术后的活动量明显更低。有必要进行一项纳入更大队列的未来研究，以检验这些活动对临床结局是否有影响（若有影响，则影响如何）。
