Introduction: minimally invasive spine surgery: the greatest advance in medicine?

In the past century, significant advances have been made in spine surgery, and in this issue of Neurosurgical Focus, we will review the myriad of treatment options currently available to treat spinal disorders. These minimally disruptive techniques and approaches to the spine have dramatically altered the natural history of previously difficult lesions and spinal conditions. Harvey Cushing would be proud of the work done in the fields of neurosurgery, radiology, engineering, physics, and orthopedics for the advancement of spine surgery. In modern medicine, there are few advances that have had a more meaningful impact on patient outcomes than minimally invasive spine procedures. Patients presenting with painful radiculopathies and neural compression can be treated successfully with minimal access procedures and sent home the same day. Sven Eicker and colleagues discuss their experience with extraforaminal lumbar disc herniations. Their minimal access microsurgical approach with the endoscopic technique seemed to produce less tissue trauma and instability, while providing significant improvement of functional outcomes. Surgical management of tumors, fractures, and spinal deformities has significantly improved with these emerging technologies and techniques. Percutaneous ped icle screw fixation for spine fractures can be done with minimal blood loss, and patients can be mobilized immediately, resulting in a decrease in postsurgical complications. Flexion-distraction spine injuries, which are extremely unstable, classically consisting of a fracture line through all 3 columns, require surgical fixation to avoid neurological deterioration, help stabilize the spine, and restore spinal balance. Historically, these injuries were all treated by means of the standard posterior open approach with instrumented fusion. Percutaneous pedicle screw fixation for these unstable spine injuries has been recently reported in the literature. Andrew Grossbach and colleagues report on their institutional experience of treating these fractures with both surgical techniques and review the current literature. Although it was a small prospective study, there was improvement in kyphotic angulation, and the authors found no significant difference in ASIA scores or the degree of kyphotic angulation between the percutaneous and open surgical groups. Percutaneous pedicle screw fixation appeared to have similar efficacy in the treatment of flexion-distraction injuries, and it allowed for reduced blood loss and tissue damage compared to open surgical techniques. Instrumentation systems have improved significantly in the past 10 years, and today’s hardware allows surgeons to realign the spine and contour the rod to the spine. How about treating spinal stenosis and spondylolisthesis with a minimally invasive interspinous fixation device? Nai-Feng Tian and colleagues found that there was a high incidence of heterotopic ossification after interspinous fixation. Lateral approaches have been applied to treat spinal conditions, such as scoliosis, in recent years. The prior treatment deformity paradigms of shortening the spine by performing osteotomies posteriorly are utilized less. Scoliosis procedures can now be staged with multilevel lateral cages that lengthen the spine, correct the deformity, increase spinal balance, provide a more natural curve, and indirectly decompress neural elements. Armen Deukmedjian and coauthors reviewed their lateral approach for adult degenerative scoliosis. They provided useful data about patient selection for the application of lateral approaches for adult scoliosis surgery. Isolated lateral interbody fusions were deemed suitable for patients with preserved spinal pelvic harmony. Sagittal imbalance may be addressed with advanced lateral approaches, such as releasing the anterior longitudinal ligament. Is there a role for minimally disruptive procedures in the treatment of intradural pathology? The article by Gandhi et al. eloquently describes utilizing a paramedian minimally invasive tubular retractor to access the spine and microscopic instruments to remove intradural pathology. Historically, intradural spinal lesions have been treated from a midline posterior approach using standard microsurgical techniques. The authors retrospectively reviewed their operative blood loss, length of stay, imaging characteristics, and outcomes. Introduction