488 - Circumferential Minimally Invasive Approach for Low-grade Isthmic Spon...

Oral Posters: MIS

Presented by: P. Tropiano - View Audio/Video Presentation (Members Only)


B. Blondel(1), K. Farah(2), P. Tropiano(3), S. Fuentes(2)

(1) Université Aix-Marseille, Orthopaedic Surgery, Marseille, France
(2) Université Aix-Marseille, Marseille, France
(3) Université Aix-Marseille, Spine Unit, Marseille, France


Introduction: Circumferential fusion for lumbar low grade isthmic spondylolisthesis (LGIS) may provide the best spinal stability and highest fusion rates. The aim of this study was to investigate results of minimal invasive circumferential fusion of LGIS and correlations between Intervertebral Foramen Surface (IFS) and other parameters.

Methods: We retrospectively reviewed cases of 43 patients who underwent a minimally invasive circumferential fusion (Anterior lumbar interbody fusion followed by percutaneous posterior pedicle screw fixation) for LGIS between January 2010 and December 2014 in our institution. Inclusion criteria were one-level (L4-L5 or L5-S1) LGIS with low back and radicular pain. Postoperative radiographic evaluations were performed at 6, 12 and 24 months. Measurements (Percentage of anterior displacement, degree of slip angle, height of the intervertebral space and the IFS) were obtained using Surgimap®.

Results: 19 patients (44.2%) were males. Mean age was 43 years old (19- 72years). The mean follow up of the series was 16.3 months (6-72months). Mean preoperative Visual Analogy Scale (VAS) for low back pain decreased from 7/10 to 2/10 and from 8/10 to 1/10 for radicular pain. Anterior displacement was reduced from 18% to 7% (p< 0.01), degree of slippage was increased from 9.8° to 15.2° (p< 0.01), intervertebral height was restored from 4.4 mm to 8.5mm (p< 0.01) with an increase of the IFS calculated at 48.8%. Restoration of intervertebral height was significantly correlated to the correction of the anterior displacement and to the restoration of the IFS.

Conclusion: Minimal invasive one stage circumferential fusion for adults´ LGIS without direct decompression, allows restoration of intervertebral height. As a consequence, this procedure lead to correction of the slippage and an increased IFS (indirect decompression effect) with a low rate of complications. It may therefore be a valuable alternative in the management of these patients.