Warren J P, Dixon A R, Culbert M P, Khan A, Mengoni M, Wilcox R K
University of Leeds, Institute of Medical and Biological Engineering Leeds UK.
Leeds Centre for Neurosciences, Leeds Teaching Hospitals NHS Trust Leeds UK.
JOR Spine. 2025 Jun 10;8(2):e70081. doi: 10.1002/jsp2.70081. eCollection 2025 Jun.
Nucleus augmentation has been proposed as an early-stage intervention for intervertebral disc degeneration and involves the injection of a biomaterial into the nucleus to restore disc height and functionality. The aim of this work was to identify clinically relevant quantitative measures that indicate the mechanical performance of the disc following nucleus augmentation.
Bovine tail bone-disc-bone units ( = 22) were mechanically tested under cyclic loading sequentially in native, artificially degenerated, and treated states. Treatment involved injection of a peptide-glycosaminoglycan mixture into the degenerated disc to a predetermined load using a syringe driver with an integrated force sensor. The stiffness restoration of the treatment was determined by comparing the biomechanical behavior of the native state to the treated state of each disc. The stiffness restoration was then compared against clinically quantifiable parameters.
No significant biomechanical differences were observed between the native and treated states, but both were significantly different from the degenerated state. The force delivered during injection was found to ramp to a steady state, followed by a final rapid increase; however, all measures associated with injection force poorly correlated with the level of stiffness restoration. Volume injected and change in disc height from injection had the strongest relationship to stiffness restoration.
This work showed that measuring the injection force for injectable treatments of the disc can provide lower and upper limits for delivery, but direct measures are stronger indicators of disc stiffness restoration.
髓核增强术已被提议作为椎间盘退变的早期干预措施，该方法涉及将生物材料注入髓核以恢复椎间盘高度和功能。本研究的目的是确定能够表明髓核增强术后椎间盘力学性能的临床相关定量指标。
对22个牛尾骨-椎间盘-骨单元在循环加载下依次进行力学测试，测试其天然状态、人工退变状态和治疗状态。治疗方法是使用带有集成力传感器的注射器驱动器，将肽-糖胺聚糖混合物注入退变的椎间盘中，直至达到预定负荷。通过比较每个椎间盘天然状态和治疗状态的生物力学行为来确定治疗后的刚度恢复情况。然后将刚度恢复情况与临床可量化参数进行比较。
天然状态和治疗状态之间未观察到显著的生物力学差异，但两者均与退变状态有显著差异。发现注射过程中施加的力会逐渐上升至稳定状态，随后最终快速增加；然而，所有与注射力相关的指标与刚度恢复水平的相关性都很差。注射体积和注射后椎间盘高度的变化与刚度恢复的关系最为密切。
本研究表明，测量椎间盘可注射治疗的注射力能够提供注射量的下限和上限，但直接测量指标是椎间盘刚度恢复的更强指标。
