Evaluation of stripping resistance of different anatomically placed screws in a sheep spine osteoporosis model

Osteoporosis is not only a disease of postmenopausal women and the elderly, it occurs due to very different etiologies and is a disease that we often have to struggle with in the daily practice of neurosurgery. With advanced and rapid diagnostic methods, more patients seek help with spine problems, causing spinal surgeons to deal with more degenerative and osteoporotic spines. This increases the rate of development of complications such as screw stripping. In biomechanical studies on the spine, the spines of large 4-legged animals (such as calves and pigs) are used. Osteoporotic spine is often overlooked because it is difficult to create. In our study, we used 6 sheep vertebrae consisting of 5-7 vertebral segments, and 4 of these vertebrae were fixed in 10% formaldehyde solution and decalcified in 10% hydroxychloric acid and EDTA solution for 15 days. We obtained relevant osteoporosis measurements by monitoring DEXA t and z scores every 2 days. We were able to easily test different screw applications in the tensile test of the osteoporotic vertebrae we obtained. We think that this technique is cheap, easily accessible and fast to use in osteoporotic spine biomechanical studies.