Treatment of L5-S1 Spondyloptosis with Multiple Pedicle Defects Through a Combined Anterior and Posterior Approach

Background: An anterior dislocation of the L5 vertebral body from the sacrum and decent into the pelvis is considered as spondyloptosis. The surgical treatment of L5-S1 spondyloptosis remains challenging and controversial. We present a case of lumbosacral spondyloptosis with multiple pedicle defects treated through a combined anterior and posterior approach.

Case description: A 38-year-old female patient suffering from L5-S1 spondyloptosis with multiple pedicle defects without any history of trauma presented with lower back pain and bilateral lower leg radiating pain. A 3-stage procedure involving L5 spondylectomy, assisted by intraoperative 3-dimensional (3D) navigation, through a retroperitoneal approach at the first stage was performed. At the second stage, decompression was performed, and pedicle screws and iliac screws were placed into L1-S2, which was assisted by intraoperative 3D navigation. At the third stage, slippage reduction was achieved by placing L4 over onto S1, where a mesh was stuffed with bone from the spondylectomy and was placed into the L4/S1 intervertebral space. The patient experienced transient lower leg weakness but returned to preoperative status soon. Radiography revealed that internal fixation was in good position. No dural tears, postoperative infections, and implantation failure were reported after 3 months of postoperation.

Conclusions: The L5 spondylectomy shortens the spine to reduce the strain on the neural elements and facilitates correction of the lumbosacral kyphosis. When long instrumentation is mandatory, such as in multiple pedicle defects, sacropelvic fixation is recommended. Intraoperative 3D navigation is helpful in such a complex case.