Becker's Spine Review

28 Thought Leadership MIS spine technology: Which are fads, and what is here to stay? 7 surgeons weigh in By Alan Condon O ver the last 30 years, minimally invasive technology has devel- oped rapidly in spine surgery, with many technologies demon- strating significant clinical advantages, but others promising more than they could deliver and largely falling by the wayside. Seven spine surgeons discuss which technologies are here to stay and which could be a flash in the pan. Question: Which minimally invasive technology trends are a fad and which are here to stay? Peter Derman, MD. Texas Back Institute (Plano): I anticipate that mo- tion preservation via disc replacement and minimally invasive and endo- scopic decompressions will increasingly be utilized. For this to happen, training in these techniques must become more widespread; we must continue to produce high-quality evidence supporting their use; and the reimbursement system must change to reflect the value generated by these operations compared to fusion. Continued innovation with development of arthroplasty devices that can be used in the setting of deformity and instability will ultimately help even more patients avoid fusion. I believe that the recent explosion in the use of interspinous and inter- laminar spacers will subside just as it has in the past. I am skeptical that the long-term data will demonstrate meaningful benefit. Furthermore, the argument that these devices are useful in patients who are too old or frail for a direct decompression is flawed — advanced surgical tech- niques allow us to perform laminectomies via comparable (or smaller) incisions with minimal blood loss. General anesthesia may not even be necessary if endoscopic techniques are employed, and patients can go home the same day. Why insert a kyphosis-inducing implant when a nondestabilizing direct decompression is an option? Joseph Lee, MD. Rothman Orthopaedic Institute (Philadelphia): Minimally invasive surgery has continued to evolve in the last 30 years. However, the goals of minimally invasive spine surgery remain constant: nerve decompression and spinal stability. Advances in navigation, robot- ics and augmented reality will continue to evolve together and allow sur- geons to perform minimally invasive surgery safely and efficiently. e next frontier will be merging information from MRI and CTs to allow robots to assist in exposure, neural decompression and disc space prepa- ration. Advances in interbody technology such as surface modification and multiplanar expansion capabilities facilitate achievement of fusion and sagittal plane correction. e traditional lateral MIS approach re- mains a successful surgical technique for a variety of degenerative spinal conditions. e recent introduction of the single-position prone lateral technique has been successful, with its proposed advantages of superior OR efficiency, better sagittal correction and ability to incorporate navi- gation/robotics. Endoscopic spine surgery, or "ultra-minimally invasive surgery," has become more popular in the last few years, but it has yet to be determined if this technique provides superior clinical outcomes compared to traditional minimally invasive techniques. James Mok, MD. NorthShore Orthopaedic & Spine Institute (Skok- ie and Des Plaines, Ill.): Here to stay are expandable interbody cages, which facilitate restoration of disc height, maximize footprint, and min- imize the amount of trialing and energy of insertion. ese attributes further enable the minimally invasive surgeon to achieve the goals of interbody fusion. e continuing advances in cage designs make this a minimally invasive technology with staying power. On the other hand, prone lateral interbody fusion, a variant of the estab- lished MIS lateral retroperitoneal interbody fusion, might prove to be a fad. It is performed in the prone position, and although an interesting concept, several problems may preclude widespread adoption. While there is only a single major value proposition — the time savings in re- positioning (the "flip") — the prone position has several potential draw- backs, including gravity dragging retroperitoneal fat and other so tis- sues into the field of view, making disc space prep and implant insertion challenging. But the major concern is safety. It is easier to consistently maintain a safe working angle (vertical) with the patient in the lateral decubitus position than the prone position (horizontal). is is critical considering the adjacent structures such as the great vessels. e effect of gravity on the lumbar plexus — considered the structure most at risk in the lateral approach for interbody fusion — is yet to be defined. Sur- geons must carefully weigh the benefit of saving time against these safety considerations when evaluating prone lateral interbody fusion. Ali H. Mesiwala, MD. DISC Sports & Spine Center (Newport Beach, Calif.): Minimally invasive surgery is fast becoming the norm across all specialties. However, the concept of MIS can be confusing for many pa- tients. In traditional spine applications, MIS refers to the use of smaller incisions or multiple stab incisions to replace large open incisions and operations. is minimizes blood loss, anesthetic time and complica- tions. Any MIS and related technologies that achieve these endpoints will be adopted, modified and improved upon, and are here to stay. e MIS trends, however, that are likely to be transient are those which have been used in spine surgery in the past and have been abandoned by surgeons, only to be repackaged and reapplied by other specialists in traditionally nonsurgical fields. Prime examples of this are spinous process distraction devices for the treatment of lumbar stenosis, poste- rior sacroiliac fusion using allogra dowels, and needle/shaving devices used for ligamentum flavum removal as a replacement for traditional laminectomies. Procedures which allow us to take advantage of the body's natural cor- ridors and orifices are here to stay. ose operations that can be done more safely, effectively, efficiently and reproducibly through small inci- sions will also be the ones that we continue to utilize. Lastly, advances in medical device design will also streamline surgery and make it less invasive. Hooman Melamed, MD. Hoag Orthopedic Institute Surgery Cen- ter - Marina del Rey (Calif.): e field of endoscopic spine surgery, which I would consider is ultra-minimally invasive, is going to become the preferred and a better alternative choice for patients who not only require decompression, but even more importantly, save many patients from having fusion done, where, with the power of endoscopy, one can perform a very thorough extraforaminal decompression without desta- bilizing the spine and decompressing nerve roots and obviate the need from doing any interbody graing and fusion. You are preserving most of the normal anatomy with very minimal blood loss, much lower risk

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