Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, Ulm University, Helmholtzstr. 14, 89081 Ulm, Baden-Wuerttemberg, Germany.
Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, Ulm University, Helmholtzstr. 14, 89081 Ulm, Baden-Wuerttemberg, Germany.
Spine J. 2022 Nov;22(11):1913-1921. doi: 10.1016/j.spinee.2022.06.010. Epub 2022 Jun 30.
Intervertebral disc degeneration represents one of multiple potential trigger factors for reduced passive spinal mobility and back pain. The effects of age-related degenerative intervertebral disc changes on spinal flexibility were however mainly investigated for the lumbar spine in the past, while intervertebral disc degeneration is also highly prevalent in the thoracic spine.
To evaluate the effect of the degeneration grade on the range of motion and neutral zone of the thoracic spine.
Experimental study including combined radiological grading of intervertebral disc degeneration and biomechanical testing of 95 human thoracic functional spinal units (min. n=4 per level from T1-T2 to T11-T12) from 33 donors (15 female / 18 male, mean age 56 years, age range 37-80 years).
Degeneration grades of the intervertebral discs were assessed using the validated x-ray grading scheme of Liebsch et al. (0=no, 1=mild, 2=moderate, 3=severe degeneration). Motion segments were loaded with pure moments in flexion/extension, lateral bending, and axial rotation to determine range of motion and neutral zone at 5 Nm.
All tested specimens exhibited degeneration grades between zero and two. Range of motion significantly decreased for grades one and two compared with grade zero in any motion direction (p<.05), showing the strongest decrease in extension comparing grade two with grade zero (-42%), while no significant differences were detected between grades one and two. Similar trends were found for the neutral zone with the strongest decrease in extension also comparing grade two with grade zero (-47%). Donor age did not significantly affect the range of motion, whereas the range of motion was significantly reduced in specimens from male donors due to the significantly higher degeneration grade in this study.
Even mild intervertebral disc degeneration reduces the range of motion and neutral zone of the thoracic spine in any motion plane, whereas progressing degeneration does not further affect its flexibility. This is in contrast to the lumbar spine, where a more gradual decrease of flexibility was found in prior studies, which might be explained by differences between thoracic and lumbar intervertebral disc morphologies.
Thoracic intervertebral disc degeneration should be considered as one of multiple potential causal factors in patients showing reduced passive mobility and middle back pain.
椎间盘退变性是导致被动脊柱活动度降低和腰背疼痛的潜在因素之一。然而，过去主要研究了年龄相关的椎间盘退行性变对腰椎柔韧性的影响，而椎间盘退变性在胸椎中也很常见。
评估椎间盘退变程度对胸椎活动度和中立区的影响。
本实验研究包括对 95 个人体胸椎功能节段（T1-T2 至 T11-T12，每个节段最少有 4 个样本，来自 33 位供体）的椎间盘退变进行放射学分级，并进行生物力学测试。这些节段来自 33 位供体（15 位女性/18 位男性，平均年龄 56 岁，年龄范围 37-80 岁）。
采用 Liebsch 等验证的放射学分级方案评估椎间盘退变程度（0=无，1=轻度，2=中度，3=重度退变）。对运动节段施加纯力矩，进行屈伸、侧屈和轴向旋转运动，在 5 Nm 时测定活动度和中立区。
所有测试样本的退变程度均为 0 级至 2 级。与 0 级相比，1 级和 2 级的活动度在任何运动方向均显著降低（p<.05），其中伸展时的降幅最大（2 级与 0 级相比，降低了 42%），而 1 级与 2 级之间无显著差异。中立区也呈现出类似的趋势，与 0 级相比，伸展时 2 级与 0 级之间的降幅最大（47%）。供体年龄对活动度无显著影响，但由于本研究中男性供体的退变程度明显更高，因此男性供体的活动度显著降低。
即使是轻度的椎间盘退变也会降低胸椎在任何运动平面的活动度和中立区，而进展性退变不会进一步影响其柔韧性。这与腰椎不同，在之前的研究中发现腰椎的柔韧性呈逐渐下降，这可能是由于胸椎和腰椎椎间盘形态的差异所致。
在出现被动活动度降低和腰背疼痛的患者中，应考虑胸椎椎间盘退变是潜在的多个致病因素之一。
