Cement Augmentation of Pedicle Screw Instrumentation: A Literature Review

Abstract

This literature review aimed to review the current understanding, indications, and limitations of pedicle screw instrumentation cement augmentation. Since they were first reported in the 1980s, pedicle screw cement augmentation rates have been increasing. Several studies have been published to date that describe various surgical techniques and the biomechanical changes that occur when cement is introduced through the screw-bone interface. This article provides a concise review of the uses, biomechanical properties, cost analysis, complications, and surgical techniques used for pedicle screw cement augmentation to help guide physician practices. A comprehensive review of the current literature was conducted, with key studies, and contributions from throughout history being highlighted. Patients with low bone mineral density are the most well-studied indication for pedicle screw cement augmentation. Many studies show that cement augmentation can improve pullout strength in patients with low bone mineral density; however, the benefit varies inversely with pathology severity and directly with technique. The various screw types are discussed, with each having its own mechanical advantages. Cement distribution is largely dependent on the filling method and volume of cement used. Cement composition and timing of cement use after mixing are critical considerations in practice because they can significantly alter the bone-cement and screw-cement interfaces. Overall, studies have shown that pedicle screw cement augmentation has a low complication rate and increased pullout strength, justifying its universal use in patients with a suboptimal bone-implant interface.

Keywords: Biomechanics; Cement; Osteoporosis; Pedicle screws; Thoracolumbar.

Fig. 1

(A, B) Example of a fenestrated pedicle screw demonstrating cannulated core and fenestrations for cement delivery.

Fig. 2

(A, B) Cement delivery demonstrated in fenestrated pedicle screws. The cement will distribute through the fenestrations and take the path of least resistance. As the pressure accumulates proximally, the cement will continue distally until the entire distal portion is covered.

Fig. 3

(A, B) Postoperative anteroposterior and lateral radiographs of the lumbar spine demonstrating fenestrated pedicle screws with cement augmentation. Written informed consent for the publication of these images was obtained from the patient. Images were provided courtesy of Laurence E. Mermelstein, MD.