552 - Reduction and Circumferential Arthrodesis of Low-grade Isthmic Spondyl...

General Session: MIS-1

Presented by: G. Edgard-rosa - View Audio/Video Presentation (Members Only)


G. Edgard-rosa(1), G. Geneste(1), M. Grau-Ortiz(1), G. Negre(1), T. Marnay(1)

(1) Clinique du Parc, Centre de Chirurgie Vertébrale, Castelnau-le Lez, France


Introduction: Surgical treatment of symptomatic low grade isthmic spondylolisthesis (SPLi) remains controversial, as there is no universal consensus on the type of procedure(s) (reduction, instrumentation, arthrodesis, and/or decompression) to be performed. However, we now have a better understanding of what the goals of surgery should be: greater attention to the restoration of spinal balance and lumbar lordosis versus anterior slippage, obtaining a solid arthrodesis, effectively resolving both leg and back pain, and minimizing the invasiveness of the procedure(s). The procedure we describe addresses these goals and our study sought to evaluate the radiographic and clinical outcomes using this method. Radiographically, we assessed the correction of sagittal balance and restoration of lumbar lordosis following ALIF in addition to the rate of successful 360° arthrodesis using only 2 unilateral percutaneous screws posteriorly. Clinically, we evaluated our ability to relieve the leg and back pain accompanying the SPLi without performing a posterior decompression.

Material and Methods: Between October 2011 and February 2015, 113 patients were entered into a prospective study on the surgical treatment of low-grade SPLi. Patients underwent clinical and radiographic follow-up at 3, 6, 12 and 24 months. All data were collected and tabulated by a clinical research assistant. All patients had a 2-step procedure: 1) an anterior reduction and arthrodesis by ALIF using BMP and 2) unilateral posterior percutaneous screw osteosynthesis. Of these 113 patients, 27 had degenerative discopathy at the level cephalad to the SPLi and underwent a hybrid construct of ALIF at the SPLi level and TDR at the level above in the first step of the procedure; these patients were studied separately.

Results: We attained a horizontal reduction of slippage of 32%, restoration of disc height of 220%, and gain of segmental lordosis of 10.3°. Sagittal balance parameters also improved, with a gain of 5.1° in the spino-sacral angle. At last follow up, the ODI score was 9, lumbar VAS score of 1.9, and radicular VAS score of 2.1. In patients with preoperative leg pain greater than their back pain, the procedure resulted in a 6.4 points improvement in the leg pain. Average satisfaction rate was 8.8/10 and 93 % of the patients would undergo the surgery again.

Conclusion: This original technique has many advantages: an improved ability to restore both sagittal balance and lumbar lordosis, a high rate of successful fusion, and the added ability to relieve the leg pain without the necessity to enter the spinal canal. In some patients where there is concomitant symptomatic adjacent level discopathy, this procedure can be used as an alternative to performing a 2-level L4-S1 arthrodesis ; this is done by performing a hybrid construct combining ALIF and TDR. The advantages of this technique, however, must be weighed against the added second step of posterior instrumentation.

Restoration of lumbar lordosis following