PROPHYLACTIC OF STRESS FRACTURES OF VERTEBRAE ADJACENT TO TRANSPEDICULAR SCREW FIXATION FOR OSTEOPOROSIS

ABSTRACT Objective: To assess the efficacy and use of vertebroplasty as a prophylactic measure to prevent stress fractures of vertebrae adjacent to transpedicular screw fixation with augmentation for osteoporosis. Methods: An experimental cadaveric study was performed to assess the overall strength of 10 cadaveric blocks of T10-L4 vertebral segments with simulation of L1 fracture and T12-L2 transpedicular 4-screw system with augmentation. T11 and L2 vertebroplasty cranial and caudal to the transpedicular system was performed in 5 blocks in the main group. Stress testing of the blocks was performed by placing them under a vertically directed load until destruction. Results: Vertically directed load on the blocks in the main group (0.84 ± 0.39831 kN) resulted in T11 vertebrae fractures. Vertebrae with augmentation were resistant to the load in the main group. T10 vertebrae fractures in the blocks of the main group occurred at a load of 1.91 ± 0.40566 kN. Conclusion: 1. The adjacent T11 vertebra is the weakest vertebra in the anatomical blocks of T10-L4 vertebral segments with simulation of L1 fracture (type A according to the AO/Magerl classification) and the T12-L2 4-screw transpedicular system with augmentation. 2. Bone cement injection into the T11 cranial vertebra adjacent to the level of fixation increases the overall strength of the blocks 3. Vertebroplasty of the overlying vertebra is an effective way to prevent its fracture and in case of osteoporosis. 4. Prophylactic vertebroplasty of the vertebra caudal to the level of fixation is unnecessary due to the insignificant risk of a fracture. Level of Evidence III; Experimental – Quasi experiments