Targeted re-innervation is therefore an umbrella term encompassing both targeted muscle re-innervation (TMR) and targeted sensory re-innervation (TSR). Interestingly, as the surgical techniques surrounding targeted re-innervation continue to evolve, seemingly concurrently, so have the advances in prosthetic design and fabrication. These parallel events will likely herald a new way of thinking about what it means to be an amputee in terms of ability to function in the future and raises many interesting questions about society as a whole. This article aims to describe some of these prosthetic innovations and their unique contributions.

One of the earliest entrants into the advanced/bionic prosthetic space was the DEKA Arm System whose developer is none other than Dean Kamen, inventor of the Segway scooter. This system now re-named LUKE (for Life Under Kinetic Evolution) is interesting because despite only a maximum of 10 degrees of freedom in optimal configuration, the system is modular enough to be almost commercially readily available and is easily configurable for both trans-radial amputees, trans-humeral amputees as well as shoulder disarticulation patients. There are also sensors for grip force feedback. Funded by DARPA, two LUKE arms have already been delivered to veterans at Walter Reed National Military Medical Center.

Touch Bionics has developed several upper extremity prosthetic products which are already commercially available and which allow users to control the prosthetic using a combination of muscle contractions and smart phone applications allowing up to 36 different hand grip motions. Along those lines, another interesting development driving prosthetic evolution is the increasing availability of lower cost, 3D printing solutions. Lyman Connor is an engineer for GE who was inspired to try to create a low-cost prosthetic hand for a young boy he met in 2013 who had lost his hand in a bicycle accident and was unable to afford an advanced prosthetic as they often cost tens or hundreds of thousands of dollars. His efforts have led to the Bionic Hand Project and the Mano-Matic 3D-printed bionic hand which uses this novel printing technology along with readily available electronic technology to create a more affordable device capable of a number of different functions.

Finally, all advancements in the field of prosthetics are necessarily high-tech related, but can still have very meaningful and profound impacts on their recipients. Until recently, many people in the small South American nation of Columbia were victims of landmine explosions set in place over the last half-century by the competing forces of the FARC rebels and the Colombian government. Unfortunately, many victims of these landmines were children who suffered amputations and the subsequent social isolation that often accompanies such tragedies. Thanks to the work of a Columbian designer by the name of Carlos Torres and his IKO Creative Prosthetic System, many of these children not only are more functional, but more integrated into their social circles. Mr. Torres conducted exhaustive research with prosthetists, clinical psychologists and surgeons, then used his creative talents along with those of the Lego Future lab (yes, that Lego) to design a unique prosthetic system that makes use of the world's favorite building blocks. The end result is a myoelectric, artificial limb which children can modify according to their desires and which allows exchanges of, for example, robotic Lego grippers for light-emitting spaceship configurations and other modular connectors which these young amputees can learn to control as they would any other myoelectric prosthetic. This project has apparently exceeded all expectations with children not only not shying away from social interactions, but proudly showing off their robotic limbs whose limitations in terms of configuration is limited only by the imagination. In my opinion, the coalescence of several factors including the advent of surgical re-innervation, the ability to fabricate and manufacture moderately complex and complex prosthetics in increasingly lower-cost ways as well as continued improvement in rehabilitation techniques will lead to a revolution not only in the prosthetics themselves, but how we think about amputees. At this point, despite what some amputees themselves may think, most people would say that missing a limb is a disability. However, it is not unreasonable to think that in the near future, people with prosthetic limbs may not only be as functional as their "able-bodied" counterparts, but perhaps even more advanced. Just asked Marcus Rehm, a unilateral below-knee amputee and long jumper who, during the German Athletics Championships in 2014, performed a long jump that would have won the silver medal two years earlier at the 2012 London Olympics.

1. https://www.thrillist.com/health/nation/luke-skywalker-bionic-arm-darpa
2. https://formlabs.com/blog/3d-printing-powered-startup-manufactures-affordable-custom-prosthetics/
3. http://designawards.core77.com/Open-Design/29865/IKO-Creative-Prosthetic-System

1. Dr. Peled: I was going to ask about endoscopic cubital tunnel decompression. Are there any unusual coding pearls that would be applicable to this type of procedure as it probably requires a bit more work than the typical open cubital tunnel release +/- transposition?
   
   Dr. Janevicius: You can append modifier 22 to the primary code (64718) to indicate that there are increased services. This modification will require documentation in the operative note and usually a letter to the payor post-operatively.
   
   
2. If you create a local tissue rearrangement (i.e. random pattern fascio-cutaneous flap to help pexy the ulnar nerve anterior to the medial epicondyle during a subcutaneous transposition, does that maneuver get coded separately with a 1402X?
   
   Dr. Janevicius: This maneuver would not constitute an adjacent tissue transfer, so 1402X is not appropriate. Subcutaneous transposition is included in code 64718. One cannot perform an anterior subcutaneous transposition without undermining, so this maneuver is included.
   
   
3. Does the coding change if you perform a sub-muscular transposition of the ulnar nerve?
   
   Dr. Janevicius: Yes, a flexor tendon/origin slide is reported separately using code 25280.