J Minim Invasive Spine Surg Tech.  2018 Dec;3(2):52-58. 10.21182/jmisst.2018.00332.

Novel Bioactive Glass Putty (S53P4) as Bone Graft Expander in Minimally Invasive Lumbosacral Interbody Fusion

• Saarenpää I
• Hirvonen J
• Rinne J
• Frantzén J

• KMID: 2562038
• DOI: http://doi.org/10.21182/jmisst.2018.00332

Abstract

Objective
This study aimed to evaluate the clinically achieved interbody fusion rate in minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) operations, when using a novel bioactive glass (BAG) S53P4 putty as bone graft expander together with local autologous bone (AB). A second purpose was to assess radiologically the subsidence of intervertebral cage into vertebral endplates.
Methods
We conducted a retrospective analysis of 20 patients operated on with MI-TLIF for 24 levels by a neurosurgeon in our clinic between 2014 and 2016. In addition to routine follow-up by static plain radiographs, the patients with special complaints were investigated with computed tomography (CT) and/or magnetic resonance imaging (MRI). An independent neuroradiologist analysed the interbody fusion by bridging bone criteria in CT scans and subsidence either in CT scans or in static plain radiographs. The patients were followed up to 12-24 months postoperative.
Results
The interbody fusion rate of 95.8% could be defined based on CT analysis of the symptomatic patients. Of the eight symptomatic patients, one had interbody cage dislocation of 2-3 mm posteriorly, lucency around a sacral screw and breakage of the other sacral screw. No subsidence of cages was observed. No postoperative infections were detected.
Conclusion
As bone graft expander, the novel BAG S53P4 putty provides at least as good interbody fusion results as the presently used bone graft expanders and enhancers with no observed subsidence or postoperative infections.

Keyword

Bone replacement materials; Minimally invasive surgery; Lumbosacral region; Spinal fusion