Preoperative phlebography in anterior L4-L5 disc approach. Clinical experience about 63 cases.

INTRODUCTION: The anterior approach of the L4-L5 disc requires a perfect knowledge of the venous anatomy. Some configurations make this approach hazardous. The purpose of this study is to classify configurations of the iliocava junction and the iliolumbar vein relative to L4-L5 and to analyze vascular complications. MATERIALS AND METHODS: The preoperative phlebographies of 63 patients (30 men, 33 women, mean age 42years) undergoing a L4-L5 disc replacement were reviewed. The height of the iliocava junction was calculated as a ratio of the distance between the discs L4-L5 and L5-S1. The position of the left iliac vein was classified into three thirds across the width of L5. The number of branches of the iliolumbar vein was noted. Surgical reports were reviewed for complications. RESULTS: The height of the iliocava junction was very high in six, high in 25, low in 26 and very low in six patients. The position of the left iliac vein was medial in 20, intermediate in 28 and lateral in 15 patients. The iliolumbar vein had one branch in 37, two in 20, three in three patients. It was not visualized in three cases. Variants of the venous anatomy included eight duplications of the left iliac vein, four wide diameters and one iliolumbar vein network pattern. Intraoperatively, three lacerations of iliolumbar veins occurred. CONCLUSION: The iliocava anatomy is very variable: the safety of an anterior approach to the L4-L5 disc depends on it. The information of preoperative phlebography can help to plan a more accessible antero-lateral approach or to switch on a posterior fusion if the anatomical situation is deemed too dangerous, such as duplicated left iliac veins. LEVEL OF EVIDENCE: Level IV. Diagnostic study.

[Thoracolumbar fractures]. / Fractures du rachis thoracolombaire.

Thoracolumbar fractures are frequent and the functional outcomes are sometimes severe. This multicentric study, including five medical centers, was performed to evaluate the long-term outcomes of the patients. One hundred and thirty six patients with thoracolumbar fracture (T11 to L2) was evaluated with a minimal follow-up of two years. Every one had a clinical exam with a score of Oswestry and an X-Ray study (before and after treatment and at revision). Most of them presented compression fractures, the most often at L1 level. On X-rays, a gain was noted on the vertebral kyphosis immediately after surgery, but there is a loss of correction over time whatever the treatment. The clinical outcomes for the patients were great, with an Oswestry average score of 6,4. A correlation was noted between this functional score and vertebral kyphosis. So, an anterior column strengthening (isolated or performed during the surgery) could improve these functional outcomes. Moreover, the Thoraco Lumbar Injury Severity Score (TLISS) seems to be a simple organigram to determine the most appropriate treatment of these fractures, with particular attention to the distraction mechanism or posterior ligamentous complex lesions. However, RMI before surgery is necessary to evaluate these lesions.