The ascendancy of spinal surgery within neurosurgery over the last 15 years has been truly remarkable. Not long ago, for most neurosurgeons spinal neurosurgery was limited predominantly to spinal decompression and intradural surgery. Changing demographics, technical and technological advances, and a highly effective strategic plan initiated by organized neurosurgery have had a dramatic impact on the scope and volume of neurosurgical practice in spine. In the United States neurosurgeons now perform more spinal surgeries, including a majority of both cervical and lumbar fusions, than do orthopedic surgeons. Advances and innovations in techniques and technologies have fueled much of this growth, and neurosurgeons have played an integral role in these developments, particularly in the fields of implant development, biomechanics, image guidance, minimally invasive surgery, cellular and molecular biologics, spinal radiosurgery, spinal cord injury, and motion preservation surgery. Continued innovation in these areas will continue to advance spinal surgery.
As rapidly as spinal surgery has developed, however, it is likely that its pace and direction will continue to rapidly evolve over the next decade and beyond. Accumulating empirical data through clinical experience and investigation, basic science research, and both individual and collective initiative will undoubtedly result in significant incremental, transformational, and translational innovations in spinal surgery.
As increased capabilities lead to increased complexity of many aspects of spinal surgery, there not only will be continued innovation but also integration of numerous technologies. Biologics, minimally invasive and/or percutaneous techniques, image guidance, and real-time imaging will allow safer, more reliable and efficient achievement of the surgical objective.
Many of the specific innovations will be driven by changing patient needs. For example, an aging population with active lifestyles will create demand for safe and effective operative and nonoperative management of the degenerative and frequently osteoporotic spine. Thus, dynamic stabilization, “soft” fusions, modification of the material properties of spinal implants, augmentation of the precarious implant-bone interface, and even facet joint replacement will be active areas of development.
Perhaps as importantly, recent advances in cellular and molecular biology have led to greater understanding of the mechanical, biochemical, and biological mechanisms underlying degenerative disc disease. It is likely that further investigation may lead to earlier and less invasive methods for modifying, stopping, or even reversing the degenerative process affecting the disc. Indeed, the use of biological materials may provide for retention or restoration of more normal spinal biomechanics without the implantation of a mechanical device.
With the increase in life expectancy and expectations, so too will the number of patients living with malignancy expand, particularly as adjuvant treatments become more effective in controlling systemic disease. More effective management of these patients by improving the quality and safety of tumor resection and spinal reconstruction will be an important area of future development. Continued advances in radiosurgery and other adjuvant treatments are also likely to become more prominent both in this patient population as well as in those with benign lesions.
The use of graft extenders, graft substitutes, and even biologics to enhance osteoinduction (e.g. recombinant human bone morphogenetic protein-2) and osteogenesis (e.g. mesenchymal stem cells, gene therapy) to improve fusion rates and reduce the reliance and morbidity of autograft harvest will continue to be an active area of development and innovation. Continued advances in motion preservation surgery will complement these innovations.
The fields of pediatric and adult deformity, long nearly exclusively the domains of orthopedic surgeons, are increasingly being populated by spinal neurosurgeons. This shift will require modification of resident and even fellowship training in neurosurgery, as it did 15 years ago. Motion preservation or restoration at junctional segments above and below long instrumented fusions, improved techniques for growth-permitting procedures for early onset scoliosis and chest wall deformities, and development of new and improvement of current techniques for less invasive anterior lumbar interbody fusion L1-S1, such as transpsoas and trans-sacral approaches, are but a few areas of current and future innovation in this rapidly developing field.
Lastly and no less importantly, the external environment within which these innovations will occur will continue to change significantly into the future. Increased scrutiny and regulation at a level not previously encountered from government, public agencies, third-party payers and advocacy groups will create new challenges. Appropriately aligned partnerships between physicians and industry, adaptive collaboration with allied physician and basic science investigators, rigorous reporting of valid clinical data, and accurate matching of specific treatment for each individual patient in an effort to maximize benefit and minimize the risk of our interventions will be crucial if we are to continue to serve the best interests of our patients. To relieve pain, restore function, and enhance the quality of life should remain unchanging principles of our specialty’s continued progress.
Paul C. McCormick, MD, MPH, FACS, is Linda and Herbert Gallen Professor of Neurosurgery and director of the Spine Center at Columbia University College of Physicians and Surgeons, New York, N.Y. The author reported no conflicts for disclosure.