The Facet Wedge: a minimally invasive technique for posterior segmental intra-articular fusion

Abstract

Minimally invasive posterior segmental instrumentation and intra-articular fusion with the Facet Wedge device. All fusion indications in degenerative disc disease without significant translational instability, postnucleotomy syndrome, spondylarthrosis, discitis. Translatory instabilities, status after decompression with partial facet joint resection, spondylolysis in the affected segment. Through a3 cm skin incision, blunt transmuscular approach to the corresponding facet joint L1/2 to L5/S1. Opening of the joint capsule and visualisation of the intra-articular space. Cartilage removal and intra-articular implantation of the Facet Wedge device. Fixation of the implant by means of two angle-stable screws inserted in the corresponding facet joint parts. Early mobilisation under thomboprophylaxis. Wearing atrunk-stabilizing brace for up to 12weeks, depending on the type and extent of the procedure. No restrictions regarding walking distance, standing and sitting immediately postoperatively after pain. In all, 27patients (mean age 51.2 years, range 30-76years) were enrolled in the prospective nonrandomized study from 02/2015 to 9/2017 with atotal of 31treated segments. In 23cases aventrodorsal surgical technique was used, in 4cases apurely dorsal procedure with interposition of an intervertebral cage. Follow-up was 2years. The Oswestry Score (ODI) improved from an average of 40.6% preoperatively to 16.6% postoperatively. The visual analog scale (VAS) for back pain improved from an average of 6.7points preoperatively to 2.1points 2years postoperatively. During this observation period, 2implant-specific complications were observed. One Facet Wedge had to be revised due to misplacement with early loosening. In another case, loss of correction occurred in apreoperatively existing first-degree spondylolisthesis with revision to adorsal screw-rod system.