The problems of neurologic injury, disc degeneration, and spinal pain are germane to all physicians who manage spinal deformities. In accordance with this Focus Issue’s theme of “Innovative Treatment Options for Spinal Deformity,” the prior four papers describe novel technologies that encompass biologic, biomechanical, and biophysical approaches.
In the area of spinal cord injury, several experimental approaches have shown promise for promoting neurologic recovery in animal models and are emerging as potential therapies ready for human clinical trials. The urgency with which an effective treatment for these devastating injuries are needed, however, should not circumvent the requirement for all potential therapies to undergo rigorous safety and efficacy evaluation in well-designed, controlled clinical trials before their acceptance as a valid treatment in humans.
Intervertebral disc matrix degradation and cellular loss are integral to the process of disc degeneration. In recent years, a variety of biologic strategies have been suggested to repair the degenerative disc. The current data suggest that a variety of cell types have the ability to survive transplantation to the disc and produce matrix proteins for at least short periods of time in animal models. At present, it remains unclear whether a cellular approach is capable of producing meaningful, long-term disc repair in humans. A significant hurdle in this line of research is the lack of understanding of the specific etiology of spinal pain, and the elusive correlation between pain and the histologic and morphologic signs of disc degeneration. Substantial future research is required to determine the efficacy of a cellular approach to disc repair and ultimately the effect of such a strategy on symptomatic disc degeneration in humans.
Biophysical methods such as heat and ultrasound have been studied for the treatment of spinal pain, although the mechanisms of action and the underlying short- and long-term efficacy of biophysical methods remain undefined. Cryotherapy, which is at a very preliminary stage of investigation, represents a potential, novel approach treatment for spinal pain. Substantial research will be required to characterize the safety and biologic effects of cryotherapy before consideration of clinical trials.
Within this section, cervical disc replacement is the farthest along the path to clinical adoption with several FDA IDE trials in progress across North America. Despite the current enthusiasm for motion preservation in the spine, it is not yet clear whether cervical disc replacement will produce a true clinical benefit when compared with cervical fusion. It is worth remembering that anterior cervical decompression and fusion has traditionally been considered one of the most successful of spine surgeries. New complications related to cervical disc replacement are likely to occur, and the longevity of the implant and consequences of wear debris are unknown.