312. CLINICAL OUTCOME IN 37 PATIENTS WITH A PERMANENT INTRASOMATIC IMPLANT WITH CRANIOCAUDAL EXPANSION FOR TRAUMATIC COMPRESSION FRACTURES A1, A2, A3.1

Abstract

Purpose of the study: Vertebroplasty with or without balloons is limited to stabilisation, without restoration of the vertebral endplates despite the risk of complications reported in the literature if this anatomic restoration is not completed before stabilising the vertebral body by cement injection.

Material and methods: Two titanium craniocaudal expansion implants were used to treat 37 patients (18 F, mean age 55years; 19 M, mean age 52 years) via the transpedicular approach for symptomatic traumatic compression fractures of the vertebral body at least 45 days earlier. The reduction was completed by injection of acrylic cement. Anatomic restoration of the vertebral body volume was measured on the 3D CT reconstructions before and after surgery. The superposition methods and calculations of the different parameters (height of the restoration and local vertebral kyphosis) were determined by an independent laboratory: the ENSAM biomechanics laboratory (Paris). Clinical criteria (VAS, Oswestry) were recorded befor and after surgery.

Results: Mean hospital stay was 2.3 days. Pain reduction was significant (70% reduction of mean VAS between the pre- and postoperative values which were unchanged at six months). The 3D images showed the capacity of these implants to restore the anatomic volume and reduce endplate impaction. The traumatic kyphosis angle was reduced on average 26% (maximum 92%) between the pre- and postoperative values.

Discussion: Using implants to maintain the anatomic restoration after fracture reduction appears to be indispensable for cement injection and a key factor for successful treatment of compression fractures of the vertebral body. Millimetric craniocaudal expansion of this new intravertebral titanium implant offers the surgeon greater control for the vertebral fracture. The imaging technique based on 3D reconstruction from pre- and postoperative scans as developed by the ENSAM should allow new standards for the evaluation of the results of surgical treatments for these vertebral fractures.

Conclusion: These preliminary results are very encouraging and should be confirmed at review with one year follow-up. They are part of a broader clinical evaluation project currently being conducted at multiple sites.