Three-dimensional printing, also known as “Additive Manufacturing”, is a rapidly growing industry, particularly in the area of spinal surgery. Given the complex anatomy of the spine and delicate nature of surrounding structures, 3D printing has the potential to aid surgical planning and procedural accuracy.
In the era of smaller incisions and minimally invasive approaches to the spine, orthopaedic spine surgeons are increasingly dependent on biologics and implant technology to achieve their ultimate goal: biologic fusion (i.e., cells meeting cells to become one non-mobile bone mass). While this does not negate the importance of good surgical carpentry, 3D printed spinal implant technology has emerged as one avenue to improving patient outcomes.
More traditional implants often do not have the best biologic properties nor favorable architecture to promote biologic fusion. The concept of material properties and good engineering has been well studied by our orthopaedic experts performing total hip and knee replacements. Over a period of decades, we have seen optimization of total joint implants to include the most compatible metals. Even the structural properties have evolved to now include more porous, lattice like structures. Such changes overall have clearly yielded better clinical outcomes for our patients.
Implants now better than ever resist corrosion and breakage. Equally important, structural enhancements such as the introduction of porosity and a nanoscale environment have augmented cellular integration (i.e. biologic fusion) without sacrificing durability. In the field of spine surgery, we consistently rely upon optimal engineering in pursuit of best possible outcomes for our patients. The addition of 3D printing to interbody implants known as fusion cages has greatly enhanced the opportunity to achieve biologic spinal fusion.
Not surprisingly, cutting edge technology is initially met with increased upfront cost and subsequent resistance to widespread acceptance. As we see more competition in the implant market, we can expect the cost of surgery to be neutralized by more favorable pricing, better patient outcomes, fewer failures, and lower likelihood for revision surgery. Imagine the scenario where a smoker or diabetic has undergone ACDF (anterior cervical discectomy and fusion) or ALIF (anterior lumber interbody fusion) surgery with a non-porous and/or plastic (PEEK) based implant; more likely than not, fusion may not occur and the patient will be back for revision surgery. In this example, 3D printed technology may offset the less ideal biologic milieu (smoking, diabetes, obesity, liver disease, kidney disease, etc.) and still yield a solid fusion outcome the first time around.
The evolution of minimally invasive spine surgery into the modern era will continue to rely upon the best surgical techniques however the next frontier may ultimately borrow from next generation engineering. 3D printed spinal implants may be the key to even better patient outcomes.
- Dr. Vamsi Kancherla, Board-Elligible Spine Surgeon