Amputation

Amputation is the process of removing parts or the entire damaged limb due to disease, trauma, infection, etc. It can range from minor procedures of the toe or finger removal, feet or hand removal to major operations of the upper and lower limbs. In replacement of the missing limbs, many amputees may wear prothesis, as known as an artificial limb, in order to return to their normal daily activities. When focusing on the military, many soldier amputees require upper-limb prothesis due to traumatic above-elbow amputation from handling of small explosive devices, which allows them to resume daily activities and engage in sports such as volleyball.

Prosthesis Category

There are many types of prostheses on the market as for now.

The earliest form of prostheses used mechanical control of prosthetic joints such as an artificial hand. It was first made for Marcus Sergius for solely cosmetic purposes during the Punic War (218-201 BC) [1, 2].

A more recent type is the microprocessor-controlled exoprosthetic knee joint developed in the 1990s which consists of various control methods with sensors and actuators. It is a more complicated prosthesis that can restore functions of the amputee’s arm.

Later, body powered prostheses were developed; they are controlled by the amputees. They are more affordable and easier to maintain since no external power source is required.

Last but the most important, externally powered prostheses are developed. Their movements are based on electrical signals generated by muscle contractions on the residual limb. Therefore, they are more precise, controllable and are widely used nowadays. However, due to cost of many intricate parts, these are the most expensive of all.

High Costs of the Prosthesis

Generally,  price of prosthetic arms is relatively high. For example, the cost of a commercial body-powered prosthetic hand can range from $4000 to $10,000, [1, 2] and the cost of an externally powered prosthetic hand can range from $25,000 to $75,000. The affordability partially challenges a lot of amputees from using prostheses.

According to Erik Scheme’s study, in the United States, approximately 30,000 persons have an above-elbow amputation and 60,000 have a below-elbow amputation. Only a small percentage of them with an upper-limb amputation regularly use a prosthesis, mainly because of a perceived lack of function and affordability among general population [3]. 

Amputation and Prosthesis in the Military

If the general population can barely afford it, what about the military? Let’s look at some military demographics. A study done by the Office of Inspector General in the Department of Veteran Affairs found data on the pre-exposure and outcomes of veteran amputees. Their amputations are mainly resulted from the war instead of solely diseases and infection. For example, the Iraq and Afghanistan war resulted in an estimated 1,573 U.S. veteran amputees [4]. In 2011 alone, a total of 6,026 veterans received amputations, with major upper limbs accounted for 0.3% [5].

Additionally, the study found that among the veterans with upper-limb amputations, at least half experience moderate to severe pain daily. This highly affects their daily activities such as sports. When resuming playing an instrument or sport, only 18.2% of veterans were able to use their usual technique without difficulty. Around 90% reported that it’s mildly to extremely difficult to play the instrument or sport as well as they would compared to pre-amputation [5]. To better evaluate the effect of amputation, the Veteran Department also used QuickDASH as a measurement of muscle and bone function loss on a scale from 1 to 100, with 100 implicating severe loss in functional use. Veteran amputees within the instruments/sports category averaged to a score of 28.9 [5]. Furthermore, to the general population, the average pain precepted on a scale of 1 to 10 ranges from 4.38 to 5.80 [6]. 

Needs of prosthesis

Regardless the struggles in returning to sports, it’s still necessary to develop and produce prothesis attachments for those in need [7]. In some cases, many attachments are made out of flexible rubber that allows players to perform the basic hand movements of serving, bumping, and spiking [8]. In the case of extreme transhumeral amputation, shoulder prosthesis, where the ball and socket joints are reversed, can be in use and found to maintain shoulder strength and torque, with some decrease in external and internal rotational strength [9]. These are great ways for amputees to return to sports since inactivity due to the inability to return to physical exercise from amputations can increase risks of obesity, diabetes, cardiovascular diseases, and other medical conditions. This is supported by a study that had concluded that mortality rates in war amputees have increased by 63% due to cardiovascular diseases [10]. 

Not only does an amputation procedure cause a restricted range of function, there are also other side effects and medical conditions associated with post operation. Amputees commonly experience phantom limb, where the amputated limb is felt to still be present even though it’s amputated or replaced by prosthesis. Among war-caused upper limb amputees, around 82% of 103 surveyed had experienced phantom limb, with at least half suffered degrees of phantom limb pain near the site of amputation [11]. However, current treatments are able to help cope with the pain, including: medication for muscle stimulation / relaxation, acupuncture, and shock therapy [12]. 

These general post-amputation side effects along with a long and difficult recovery in returning to sports and hefty prices attached to specialized and general prosthesis are the main difficulties that many current amputees face. In response to these issues, there are many different advances in biomedical research and technologies that are able to reduce and minimize such problems.