Cement leakage in pedicle screw augmentation: a prospective analysis of 98 patients and 474 augmented pedicle screws

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Loosening and pullout of pedicle screws are well-known problems in pedicle screw fixation surgery. Augmentation of pedicle screws with bone cement, first described as early as 1975, increases the pedicle-screw interface and pullout force in osteoporotic vertebrae. The aim of the present study was to identify cement leakage and pulmonary embolism rates in a large prospective single-center series of pedicle screw augmentations.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>All patients who underwent cement-augmented pedicle screw placement between May 2006 and October 2010 at the authors' institution were included in this prospective cohort study. Perivertebral cement leakage and pulmonary cement embolism were evaluated with a CT scan of the area of operation and with a radiograph of the chest, respectively.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>A total of 98 patients underwent placement of cement-augmented pedicle screws; 474 augmented screws were inserted in 237 vertebrae. No symptomatic perivertebral cement leakage or symptomatic pulmonary cement embolism was observed, but asymptomatic perivertebral cement leakage was seen in 88 patients (93.6%) and in 165 augmented vertebrae (73.3%). Cement leakage most often occurred in the perivertebral venous system. Clinically asymptomatic pulmonary cement embolism was found in 4 patients (4.1%).</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Perivertebral cement leakage often occurs in pedicle screw augmentation, but in most cases, it is clinically asymptomatic. Cement augmentation should be performed under continuous fluoroscopy to avoid high-volume leakage. Alternative strategies, such as use of expandable screws, should be examined in more detail for patients at high risk of screw loosening.</jats:p></jats:sec>

Novel Surgical Strategy for Treating Osteoporotic Vertebral Fractures with Cord Compression

“…It has been proved that cement augmentation can increase pullout strength and biomechanical stability from 96% to 278%. Although bone cement augmentation of pedicle screw bares a risk of cement leakage ranging from 0% to 73.3%, the majority of them are asymptomatic. Only 7.3% of asymptomatic cement leakage of pedicle screw occurred in this study.…”

Venöse Paravasate nach Augmentation von Pedikelschrauben – ein unterschätztes Risiko

“…Bei 88 Patienten (94 %) wurden im CT Zementparavasate beobachtet, überwiegend in den paravertebralen Venen. In 4 Fällen (4 %) kam es zu Lungenembolien, die aber alle asymptomatisch waren [10].…”

“…Dies ist deutlich seltener als bei den nicht gebrochenen Wirbeln, bei denen Müller et al in 94 % Paravasate beobachtet haben [10].…”

Osteoporotische Wirbelkörperfraktur

“…Bei all den Vorteilen, welche die Augmentation des Schraubenlagers mutmaßlich bietet, muss man immer einen kritischen Blick auf die zusätzlichen Risiken werfen, die sich durch das Einbringen von PMMA in den Schraubenkanal oder durch die Pedikelschraube ergeben. So ist die beschriebene Paravasatrate deutlich über derjenigen der Kyphoplastie und wird in aktuellen Studien mit über 70 % und mit einer Rate an Zementembolien über 4 % angegeben [38]. 10 Jahren für die traumatischen Verletzungen der Wirbelsäule beschrieben [40] und zeigen in klinischen Kontrollen einen geringeren kyphotischen Korrekturverlust sowie weniger Implantatlockerungen im Vergleich zur isolierten dorsalen Instrumentierung.…”