Introduction: Pedicle subtraction osteotomy (PSO) has been described for correction of fixed sagittal imbalance, typically allowing up to 30 degrees of correction of lumbar lordosis. This procedure is typically done in the prone position using a bipedicular approach. However, it can be associated with significant morbidity, including major operative blood loss. Minimally invasive lateral approaches have increasingly been used for the treatment of degenerative disease and spinal deformity. These have included thoracolumbar interbody fusions, corpectomies, and thoracic discectomies. In this technical note, we present the first report of a novel application of the minimally invasive lateral approach for a hybrid PSO.
Methods: A 69 year-old male with multiple previous thoracolumbar operations, ultimately with a T10 – S1 instrumentation and fusion, presented with gluteal and thigh pain with a crouching gait secondary to compensating for a positive sagittal balance. In a staged procedure, anterior wedge resection of the L1 vertebral body was performed using the minimally invasive retroperitoneal lateral approach. The patient was then placed prone for the completion of the pediculectomies, closure of the PSO, and definitive posterior rod instrumentation.
Results: Preoperatively, he had 9 cm of positive sagittal imbalance and 15 degrees of lumbar lordosis, with anterior wedging of the L1 vertebral body. Postoperatively, the patient had 47 degrees of lumbar lordosis for a gain of 32 degrees. Blood loss was minimal. He remains neurologically intact and was discharged home four days after the completion of the procedure.
Conclusions: This case displays the technical feasibility of using a minimally invasive lateral approach for PSO. While additional experience and follow up is required to further characterize the technical challenges and potential complications, our novel application for the minimally invasive lateral approach demonstrates its viability in achieving correction for sagittal imbalance via a hybrid PSO.
Patient Care: The application of the minimally invasive retroperitoneal lateral approach for hybrid pedicle subtraction osteotomy can, with additional experience and refinement, provide another option in the surgical armamentarium for the treatment of spinal deformity.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the indications for pedicle subtraction osteotomy; 2) Describe the potential advantages, disadvantages, and technical challenges of the lateral approach for PSO.