How the clinical dosage of bone cement biomechanically affects adjacent vertebrae

Abstract

Objective: This study evaluated the biomechanical changes in the adjacent vertebrae under a physiological load (500 N) when the clinically relevant amount of bone cement was injected into fractured cadaver vertebral bodies. Methods: The embalmed cadaver thoracolumbar specimens in which each vertebral body (T12-L2) had a BMD of < 0.75 g/cm 2 were used for the experiment. For establishing a fracture model, the upper one third of the L1 vertebra was performed wedge osteotomy and the superior endplate was kept complete. Stiffness of specimens was measured in different states. Strain of the adjacent vertebral body and intervertebral disc were measured in pre-fracture, post-fracture, and after augmentation by non-contact optical strain measurement system. Results: The average amount of bone cement was 4.4 ml (3.8-5.0 ml). The stiffness of after augmentation was significantly higher than the stiffness of post-fracture (p < 0.05), but still lower than pre-fracture stiffness (p < 0.05). After augmentation, the adjacent upper vertebral strain showed no significant difference (p > 0.05) with prefracture, while the strain of adjacent lower vertebral body was significantly higher than that before fracture (p < 0.05). In flexion, T12/L1 intervertebral disc strain was significantly greater after augmentation than after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05); L1/2 vertebral strain after augmentation was significantly less than that after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05). Conclusions: PVP may therefore have partially reversed the abnormal strain state of adjacent vertebral bodies which was caused by fracture.

Risk assessment for sandwich vertebral fractures in the treatment of osteoporosis vertebral compression fractures using two methods of bone cement reinforcement

“…Theoretically, bone cement might increase the pressure on the adjacent disk, resulting in the deformation of the adjacent endplate, causing fractures in the endplate and nearby cancellous bone. Thus, stress and strain changes can further exacerbate, ultimately leading to adjacent vertebral fractures [ 21 ]. In the present study, when the Cobb angle was large, the fracture rate of the dissected vertebral body was higher, and PVP was higher than PKP.…”

Clinical Outcomes of Fracture Haemorrhage Aspiration for Percutaneous Vertebroplasty in Treating Osteoporotic Vertebral Compression Fractures

“… 22 , 23 Other studies have shown that large bone cement dosages do not show greater benefits and lead to asymmetrical cement distribution and excessive vertebral stiffness. 6 , 8 , 20 , 21 In some cases, even if the injection volume of bone cement was increased, bone cement was an uncertainly connected endplate, indicating that the amount of bone cement is not the decisive factor in improving the distribution pattern. 23 , 24 Based on these findings, we explored a new approach.…”

Bone Cements Used in Vertebral Augmentation: A State-of-the-art Narrative Review

“… 5 A mismatch between mechanical properties of fractured bone and nonfractured bone may be partially reversed by the addition of an adequate amount of BC and may result in less abnormal strain on the adjacent vertebral bodies. 13 …”

“…5 A mismatch between mechanical properties of fractured bone and nonfractured bone may be partially reversed by the addition of an adequate amount of BC and may result in less abnormal strain on the adjacent vertebral bodies. 13 When engineering ABCs, cement viscosity is one of the most important characteristics. The viscosity of the cement affects injectability, leakage, retention in the vertebral body, and the final mechanical properties of the set cement.…”