Lukas Weiser, Kay Sellenschloh, Klaus Püschel, Michael M. Morlock, Lennart Viezens, Wolfgang Lehmann, Gerd Huber


June 2020, Volume 29, Issue 6, pp 1297 - 1303 Original Article Read Full Article 10.1007/s00586-020-06376-w

First Online: 23 March 2020

Reduced cement volume does not affect screw stability in augmented pedicle screws

Purpose

Cement augmentation of pedicle screws is able to improve screw anchorage in osteoporotic vertebrae but is associated with a high complication rate. The goal of this study was to evaluate the impact of different cement volumes on pedicle screw fatigue strength.

Methods

Twenty-five human vertebral bodies (T12–L4) were collected from donors between 73 and 97 years of age. Bone density (BMD) was determined by quantitative computed tomography. Vertebral bodies were instrumented by conventional pedicle screws, and unilateral cement augmentation was performed. Thirteen vertebrae were augmented with a volume of 1 ml and twelve with a volume of 3 ml bone cement. A fatigue test was performed using a cranial–caudal sinusoidal, cyclic load (0.5 Hz) with increasing compression force (100 N + 0.1 N/cycles).

Results

The load to failure was 183.8 N for the non-augmented screws and was increased significantly to 268.1 N (p 

Conclusion

Cement augmentation significantly increases pedicle screw stability. The benefit of augmentation on screw anchorage was not significantly affected by reducing the applied volume of cement from 3 ml to 1 ml. Considering the high risk of cement leakage during augmentation, we recommend the usage of a reduced volume of 1 ml bone cement for each pedicle screw.

Graphic Abstract

These slides can be retrieved under Electronic Supplementary Material [graphic not available: see fulltext].


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