Haruo Kanno, Toshimi Aizawa, Ko Hashimoto, Eiji Itoi


May 2020, pp 1 - 8 Original Article Read Full Article 10.1007/s00586-020-06451-2

First Online: 18 May 2020

Purpose

Percutaneous pedicle screw (PPS) fixation has been commonly used for various spine surgeries. Rigid PPS fixation is necessary to decrease the incidence of screw loosening in osteoporotic spine. Recently, we have reported biomechanical advantages of augmentation technique using hydroxyapatite (HA) granules for PPS fixation in synthetic bone. However, its biomechanical performance in augmenting PPS fixation for osteoporotic spine has not been fully elucidated. The aim of the present study is to perform a cadaveric biomechanical analysis of PPS fixation augmented with HA granules.

Methods

Thirty osteoporotic lumbar vertebrae (L1–L5) were obtained from 6 cadavers (3 men and 3 women; age 80 ± 9 years; bone mineral density 73 ± 9 mg/cm3). The maximal pullout strength and maximal insertion torque were compared between the screws inserted into the vertebrae with and without augmentation. In toggle testing, the number of craniocaudal toggle cycles and maximal load required to achieve the 2-mm screw head displacement were also compared.

Results

The maximal pullout strength in the screws augmented with HA granules was significantly greater compared to those without augmentation (p 

Conclusion

The PPS fixation was significantly enhanced by the augmentation with HA granules in the osteoporotic lumbar spine. The PPS fixation augmented with HA granules might decrease the incidence of screw loosening and implant failure in patients with osteoporotic spine.


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