Surgical treatment of unstable spondylodiscitis with posterior instrumentation and bioactive glass (BAG-S53P4): surgical technique and results at medium-term follow-up.

Abstract

The article aims to describe the novel surgical technique of filling anterior spine cavitations in pyogenic spondylodiscitis (PS) using bioactive glass S53P4 (BAG-S53P4) (BonAlive^®) in association with posterior spinal stabilization alone and its results in the first three patients. The technique starts with a posterior approach and instrumentation of the spine, total or partial laminectomy (when needed), debridement of the intervertebral space and cavity filling with BAG-S53P4, without any additional anterior instrumentation (i.e., meshes/cages). We retrospectively reviewed the first three cases of spondylodiscitis surgically treated with this technique at the department of orthopaedic surgery of the ASST-Ovest Milanese, Legnano Hospital (Italy). Functional outcomes, pain level, and C-reactive protein (CRP) trends were reported. Serial plain radiographs were collected, and a computed tomography (CT) scan was performed after a period of 2-3 years. A rapid improvement and healing from infection were observed in all cases with progressive spinal fusion and restoration of the previous quality of life. We did not observe major adverse events. BAG-S53P4 can be safely introduced in the disk space through a posterior approach to fill vertebral cavitation when the posterior wall is almost intact. It may be considered a safe and useful biomaterial in the surgical treatment of spondylodiscitis, helping in the eradication of the infection and promoting progressive spinal fusion. With this technique, anterior instrumentation and double approaches could be avoided in case of limited bone defects and moderate spinal deformity.