Latest advances in spine surgery

MIS, Endoscopic Surgery, Robotic surgery, 3-D printing.

Written by Bansal Gaurav, MBBS, MS, MCh (AIIMS), IFAANS (USA)

Endoscopic Spine Surgery (ESS) and MIS are currently the foremost example of how far we’ve come in the surgical treatment of our patients with back and neck pain. With these techniques, the risks, recovery time, and surgical complications have decreased greatly.

During the past 2 decades, many surgical specialties have used newer technologies in parallel with different scientific developments for the purpose of decreasing morbidity and mortality. No doubt, spine surgery also follows this trend.

Endoscopic Spine Surgery (ESS) and MIS

Spine surgery has advanced dramatically with the technology surrounding minimally invasive surgical (MIS) techniques. Surgical materials, nerve monitoring, and computer-aided navigation have improved significantly recently.

According to data, there are approximately 16 lac instrumented spinal procedures performed each year in our country. Minimizing the amount of tissue injury, trauma and post-operative pain are important to optimize any patient’s recovery from back surgery. Over the years, we have seen great strides in spine surgery technology, equipment, instrumentation, and procedures.

Minimally invasive surgical (MIS) techniques are a part of the daily practice of many spine surgeons. There are four virtues of MIS in spine: less surgically induced tissue damage; predictable clinical outcomes, such as decreased blood loss, shorter hospital stays and faster postoperative rehabilitation; clinical efficacy; and reasonable cost.

For some patients who have spinal instability or have been recommended spinal fusion, it is important to understand what minimally invasive options may be available.

Advances in spine imaging, such as MRI, allow surgeons to see smaller and smaller spinal problems. Individual spinal nerves, bone spurs, and small disc fragments can be easily seen and diagnosed. Similarly, spinal surgery techniques have advanced to the point where some procedures involve incisions less than 1 cm.

Many modern techniques can be described as “minimally invasive” surgery, or “MIS.” For some patients, a minimally invasive procedure may be a better surgical option than a traditional or “open” spinal surgery. Instead of removing muscle attachments from bones, a minimally invasive surgery spreads and pushes muscles out of the way.

X-rays, computer-aided navigation techniques, and specialized tubes or retractors with special cameras or microscopes have led to major advances in the capabilities of MIS and Endoscopic Spine surgery. In addition to a smaller incision, these surgeries has several advantages. It has been shown, on average, to cause decreases in blood loss, post-operative pain and narcotic use, soft tissue damage, and number of days spent in the hospital. On average, patients have a faster recovery, and return to normal activity and work faster.

When spine surgery is recommended, it is important for patients to discuss minimally invasive options with their surgeon. Minimally invasive surgery and Endoscopic surgery, is not the right option for all patients. It is important to understand why you may not be a candidate for MIS or Endoscopic surgery. Some surgeons have not been trained using these techniques, and do not offer them even though their patients may benefit. Before undergoing a spinal surgery, you should have a good understanding of the procedure itself and what to expect during the recovery process. Since pain and recovery are personal and individualized for each patient, no surgeon can guarantee a particular recovery course. However, for many patients, an MIS or Endoscopic surgery option may result in a smoother and more successful outcome.

Most surgeons turn to MIS techniques exclusively for trauma and degenerative conditions. In particular, vertebroplasty/kyphoplasty, endoscopic disc surgery, percutaneous fixation techniques and minimally invasive interbody fusion have been proved as effective procedures with short hospital stay and decreased morbidity in several studies.

Robotic surgery

Spine surgery is an advanced subspecialty that relies on meticulous motor skills to carefully manipulate vulnerable structures, such as the neural elements. Sometimes spine surgeons must work through narrow areas that are surrounded by critical anatomical structures. Furthermore, these procedures may take a long time to complete and can therefore cause of mental and physical fatigue for the surgeon. Based on these facts, spine surgery is a good candidate for robotic surgery.

Robotic surgery gained its popularity with intrapelvic, complex surgeries that consisted of gynecologic oncology, prostatic and rectal surgery. Among spinal interventions, pedicle screw fixation is the most common area in which robotic-assisted surgery is used. Studies show the accuracy of robotic-assisted pedicle screw insertion is sufficient. On the other hand, Laudato and colleagues found no significant difference between fluoroscopy-assisted free hand, O-arm-assisted and robotic-assisted pedicle screw insertion groups in a study. Thus, it can be said robotics in spine surgery is still in its infancy and needs more adaptation to different complex procedures, such as tumor resection and deformity correction, to gain widespread use in this specialty.

Will robotic surgery in spine eventually gain universal appreciation as has been the case with knee arthroscopy or will the appreciation for robotic surgery be limited to medical history books and deemed as an approach that was no more than an expensive, marketing gadget? I think it is too early to answer this question accurately since we need more evidence for drawing any conclusions.

Additive manufacturing

Additive manufacturing — 3-D printing — emerged in the new millennium. Economist and social theorist Jeremy Rifkin described additive manufacturing or 3-D printing as a feature of the “third industrial revolution.” It allows 3-D renderings to be become physical objects by way of a printer that uses CAD software and stereolithographic design files. The 3-D printing technology has revolutionized prototyping and is now found in many non-medical applications. In medicine, the technology has applications in orthopaedic surgery, neurosurgery, maxillofacial surgery, cardiac surgery and spine surgery, among various other disciplines.

In spine surgery, there are three main areas in which 3-D printing is being used: anatomic haptic models for preoperative planning; surgical guides for the placement of pedicle screws; and patient-specific titanium implants for spinal column reconstruct ion.

Spine surgery is inherently complex due to the surrounding anatomy. Intraoperative patient-specific pedicle screw placement guides created with preoperative data obtained from imaging studies may help surgeons avoid the risks of these procedures. One of the first studies of pedicle screw placement guides used in adolescent idiopathic scoliosis patients was a pilot study presented at the Scoliosis Research Society Annual Meeting in September 2017. It showed use of these low-cost, personalized 3-D guides is as safe and effective as computer/navigation-based techniques with 92% accuracy. However, the major disadvantage of this technology is the requisite CT scan that is needed to model the spinal column because it resulted with high radiation exposure to the patient. Future studies should focus on modelling structures using imaging techniques that have low radiation.

As spine surgeons, we must identify emerging technologies for obtaining better outcomes with decreased morbidity and mortality in complex surgeries. However, the cost-benefit dilemma must be considered in the decision-making process related to adoption of new technologies in spine surgery.