Novel L5-S1 interbody fusion technique for root anomalies or abnormal root configurations of L5-S1 foramens

Abstract

Purpose: We show in this study that if a root anomaly does not permit access to the disc space in the usual way, the technique we define here can be used. If the patient has a root anomaly or an abnormal root configuration at this level, inevitably, an anterior approach is preferred. Materials and Methods: The patient's previous skin incision was used; the L5-S1 space was reached laterally without entering the midline. The dura in the midline and the L5 and S1 roots on both sides were exposed. They were reached through the adjacent points of both S1 pedicles by going around the upper edge of the sacrum, allowing the disc space to be evacuated. An autologous bone graft was placed on both sides of the space. T10-S1 pedicle screws were placed. An L1 pedicle osteotomy was performed and joined using two rods. Results: The patient's back and leg pain disappeared after the surgery. The plain X-rays showed that the sagittal balance was restored. In this case, it is impossible to see the disc space because the nerve root blocks its view. Conclusions: The classic approach in such cases is to perform a fusion by either a transperitoneal or retroperitoneal approach or by performing a posterior intertransverse fusion. However, it is very challenging to execute an anterior L5-S1 fusion on a patient with pelvic retroversion. When the spinopelvic junction is included in the fusion, one common problem observed is pseudarthrosis. The surgical technique defined in this article makes it possible to drill the bone tissue through the disc space and the upper surface of the sacrum, accessing the pedicle bone. Then, a discectomy is performed at the disc space, a bone graft is placed, and a posterior lumbar interbody fusion is performed.