Minimally Invasive Spinous Process Fixation and Fusion

Minimally invasive spinal techniques have been developed to minimize the perioperative morbidity associated with traditional, open spinal procedures, all the while maintaining similar or superior clinical outcomes. Interspinous rigid fixation/fusion devices (IFDs), which can be implanted in the lumbar spine through small midline incisions with minimal soft tissue dissection, allow for rigid spinal fixation, most commonly when implanted to supplement anterior, lateral, or posterior interbody fusions. These devices are distinct from the class of interspinous “bumpers” or spacers designed to distract the interspinous space and provide dynamic fixation. While an abundance of biomechanical data exists to support the use of IFDs, particularly as compared to stand-alone interbody, unilateral, or bilateral pedicle screw constructs, clinical studies reporting of surgical morbidity and patient outcomes are more sparse. The familiar surgical approach and minimal soft tissue dissection required for implantation of IFDs may mitigate both the steep learning curve required for minimally invasive posterior pedicle screw placement and perioperative morbidity, though more study is required to draw definitive conclusions