Outrigger rod technique for supplemental support of posterior spinal arthrodesis

Abstract

Background context: Instrumentation failure is a recognized complication after complex spinal reconstruction and deformity correction. Rod fracture (RF) is the most frequent mode of hardware failure in long-segment spinal fusion surgery. This complication can negatively impact the clinical outcome by producing spinal pain, functional compromise, instability, and loss of deformity correction.

Purpose: To describe the outrigger rod surgical technique.

Study design: Review of literature, case review, and surgical technique description.

Patient sample: Two clinical cases are presented.

Outcome measures: Rod fracture.

Methods: Outrigger rod placement in posterior spinal arthrodesis is performed by supplementing primary spinal rods with outrigger rods attached with cranial and caudal side-by-side connectors providing a more robust construct.

Results: This technique may be beneficial for preventing RF in patients undergoing surgery for three-column osteotomy for sagittal imbalance; pseudarthrosis surgery with previous hardware failure; transforaminal lumbar interbody cage placement at multiple levels in realignment procedures, long-segment spinal arthrodesis with impaired host fusion potential; long-segment instrumented fusions that span the cervicothoracic, thoracolumbar, or lumbosacral junction; and across spinal segments at high risk for RF (eg, after extensive resection of vertebral elements in the management of metastatic malignancy).

Conclusions: The risk of rod failure is substantial in the setting of long-segment spinal arthrodesis and corrective osteotomy. Efforts to increase the mechanical strength of posterior constructs may reduce the occurrence of this complication. The outrigger rod technique increases spinal construct stiffness and may improve the longevity of the construct. This technique should reduce the rate of device failure during maturation of posterior fusion mass and limit the need for supplemental anterior column support.

Keywords: Instrumentation failure; Long-segment fusion; Ourigger rod; Revision surgery; Rod fracture (RF); Spinal deformity.