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March 2009 • Vol. 5, No. 2
Advancing Orthotic and Prosthetic
Care Through Knowledge

Improving Outcomes for Bilateral Transfemoral Amputees: A Graduated Approach to Prosthetic Success

Kevin Carroll, MS, CP, FAAOP
Randy Richardson, RPA


Patients with bilateral transfemoral amputations face a complex process of physical and emotional recovery. Though regaining mobility and learning to walk on prostheses are usually the ultimate goals, most new amputees are overwhelmed by how difficult it is to become a highly functional bilateral prosthesis user. Issues of stability, balance, and energy expenditure are magnified. Often, even after months of intensive effort at rehabilitation, patients lose confidence that they will be able to walk comfortably and independently on two transfemoral prostheses. It may seem that their most practical option is to accept using a wheelchair for mobility. For many, facing this reality can lead to depression, physical deconditioning, and weight gain.

Table 1:

Table 1

In working with numerous such patients, some of whom are recently wounded American service members, the authors have developed a comprehensive approach to improving long-term prosthetic outcomes for bilateral transfemoral amputees. This strategy includes four broad phases: building confidence in prostheses; walking on short legs with training feet; graduated increases in height; and walking on full-length legs with knees and prosthetic feet. The following case studies reflect the experiences of several bilateral amputees—people who have navigated the winding road that lies between the severe trauma of bilateral limb loss and the possibility of regaining mobility and independence.

Phase 1: Building Confidence in Prostheses

Improving prosthetic outcomes for bilateral transfemoral amputees has to begin with building their confidence in the usefulness of prostheses. The patients featured in these case studies each initially presented in a wheelchair and stated that they did not believe they would ever be full-time, functioning, independent prosthesis users. In every case, the catalyst that changed their thought process was meeting a bilateral transfemoral amputee who had successfully achieved being a fulltime prosthesis user.1

Staff Sgt. Heath Calhoun, ret., age 29, lost both of his legs above the knee in 2003 while serving in Iraq. He had nine months of inpatient rehabilitation and prosthesis training. Over the next two years, he tried different sockets and components, including a pair of computerized knees, but he continued to struggle with balance. The difficulty of walking on bilateral prosthetic legs outweighed the benefits, and Calhoun came to believe it was impossible to be a full-time prosthesis user and that he would always rely on a wheelchair.

In 2006 Calhoun attended a workshop at the Amputee Coalition of America (ACA) national conference and met bilateral transfemoral amputee Cameron Clapp. Clapp was wearing two prosthetic legs and a prosthetic arm on his right side. "I was astounded to see what he was doing," Calhoun says. "It was almost as if he could function like a person with two natural legs." Clapp had become a prosthesis user in 2002 by following the graduated approach to fitting a bilateral transfemoral amputation (figure 1). He became Calhoun's peer support, encouraging him to try prostheses again using the graduated approach. "Be determined and ambitious," Clapp says. "You have to want to do something about your situation."

Figure 1: Cameron Clapp with his prosthetist, Kevin Carroll, MS, CP, FAAOP.

Figure 2: Staff Sgt. Heath Calhoun, ret., enjoys his independent lifestyle on full-length prosthetic legs with microprocessor-controlled knees.

In spite of using a wheelchair full time, Calhoun had remained physically active, learning to snow ski just five months after his injury. In 2005, he began training on a hand cycle and successfully completed the Soldier Ride National Tour, a 4,200-mile cross-country bike ride. His strength, stamina, and healthy weight meant that he was physically prepared to begin phase 2, walking on short legs with training feet. After three months with graduated increases in height, Calhoun transitioned to full-length prosthetic legs with microprocessor-controlled knees (figure 2).

Many people with bilateral amputations who use a wheelchair are seriously deconditioned and often overweight—two factors that will inhibit their ability to move into phase 2. For these patients, conditioning, stretching, and losing weight must begin as soon as possible. A comprehensive physical therapy program2 is vital to their ability to move forward in their prosthetic rehabilitation. Every effort should be made to locate a physical therapist who is experienced in working with amputees, including prosthesis users. Patients who are unable to commit to the rigorous work of getting into good physical shape will continue to struggle with the demands of becoming a prosthesis user and are likely to prefer using a wheelchair.

One potential psychological barrier for some patients is their unwillingness to be short. They may have strong feelings about being returned to their former height and are very self-conscious about the idea of going out in public wearing short legs. In fact, the authors have worked with several people who wanted to be prosthesis users but could not come to terms with starting out on short legs. In these cases, patients will typically insist on wearing full-length legs and will often struggle for months and even years trying to be functional on full-length legs. Eventually, the frustration of using full-length legs can bring them to a point at which they will try short legs, or they give up entirely on using prosthetic legs for mobility. Peer-to-peer support from another patient who has already been through this process can be very helpful to the new patient.1,2

Engaging the support of the patient's family and friends is an important component of phase 1. Many family members are very involved with helping the person with bilateral transfemoral amputations and as a result fall into behaviors that prevent the patient from doing even simple things without assistance. Often, family members and friends are trying to protect the patient from being disappointed again or from doing anything that might lead to potential physical injury, such as falling. The clinician must help family members and friends understand that they play a vital support role in the patient's rehabilitative success. Accepting and encouraging the patient completely as a short person is a good place to start.

Patients are ready to move into the next phase when they have made progress in two vital areas. On a psychological level, they have renewed hope that there is a path to being a successful prosthesis user. Physically, they are taking the necessary actions of physical therapy, daily stretching, conditioning, and weight control.

Phase 2: Walking on Short Legs ("Shorties") with Training Feet

After many years of clinical experience, the authors have come to believe that it is counterproductive to expect bilateral transfemoral amputees to move directly from a wheelchair to wearing full-length prosthetic legs.3 A more practical and realistic step is to focus on getting patients out of the wheelchair by fitting them initially with short prosthetic legs with custom-designed training feet. The absence of pylons and knees have numerous benefits, including stabilizing balance and reducing the risk of injury from falls.1 Although patients will experience significant energy expenditure as they begin walking on "shorties," it still requires substantially less energy than walking on full-length legs. Using short legs without prosthetic knees can reduce heart rate and oxygen use by 7-23 percent and can increase walking speed by up to 25 percent.4

Figure 3: Anatomically contoured transfemoral sockets accommodate the bone, muscle, vascular, and nerve structures of the residual limbs.

Short legs include anatomically contoured prosthetic sockets and custom-made training feet. The fit of the sockets is critical to the patient's success. Sockets must be comfortable, accommodating the bone, muscle, vascular, and nerve structures of the residual limbs5 (figure 3). As the patient becomes active, the muscles in the residual limbs strengthen and grow; the flexible socket material locks onto the bones and muscles without causing surface damage to the skin. The secure fit of direct-contact suction sockets makes them the preferred approach for most bilateral users. Some people may need to wear gel liners to help control swelling or to protect skin from damage. Direct-contact suction sockets enhance proprioception while gel liners may diffuse it.6 Several patients who have used the graduated approach to bilateral transfemoral prostheses have commented to the authors on the increased feeling and control they experience with direct-contact suction sockets.

Figure 4: Small training feet are custom made for each patient.

In prosthetic facilities that train patients on short legs, it is often customary to use actual prosthetic feet that are turned backwards, providing less forefoot for the person to deal with while learning to walk. While this practice works for some patients and is easy for the clinicians, the authors have observed that many patients are discouraged by the appearance of a backward foot. In the graduated-fitting approach, the small training feet that are custom made for each patient receive a favorable response and also increase functional ability (figure 4).

Cameron Clapp, age 22, lost both legs above the knee and his right arm above the elbow in 2001 when he was struck by a train (figure 5). His desire to become a prosthesis user provided the initial momentum for this graduated approach to prosthetic fitting. Initially, Clapp was not willing to wear short legs and insisted on going right into full-length legs. He was diligent in physical therapy and used parallel bars at home to continue his walking training, but even after months of effort, he found that wearing full-length prosthetic legs was too difficult. Clapp agreed to try shorties after all, had several gradual height increases over a period of five months, and then successfully graduated to full-length legs.

By committing to the use of shorties all day, every day, patients quickly improve their physical condition and develop daily routines that do not involve a wheelchair. It is counterproductive to use the shorties for only an hour or two a day while continuing to use a wheelchair for the majority of daily tasks. Patients may believe that using a wheelchair will be quicker in covering long distances, such as when going to a shopping mall.7 Though this may be true, it actually works against their goal of becoming independent prosthesis users. Sitting in a wheelchair puts them in a position that can cause flexion contractures in the residual limbs. Encouraging patients to stop using a wheelchair completely and wear the shorties full time, regardless of how long it might take to do certain tasks, is one way that family members and friends can help patients make progress. An ongoing physical therapy program should continue and will also help patients improve their mobility on shorties.

Another component of phase 2 is teaching patients how to fall and how to get back up. Often, clinicians, therapists, and family members are very focused on never allowing patients to be in a situation where they could fall. Falls are an inevitable part of learning to be a bilateral transfemoral prosthesis user. It is much less frightening to fall when wearing shorties than when wearing full-length legs, and the incidence of injury also is much lower. The most difficult tasks include stepping off curbs, walking down stairs, and walking down ramps. In order to learn to successfully navigate these obstacles and build their confidence, patients need to put themselves in an environment with curbs, stairs, and ramps.

Figure 5: Trilateral amputee Cameron Clapp was 15 years old when he was struck by a train.

Figure 6: Today, Clapp is a very active 22-year-old college student.

The role of the clinician from this phase forward is not only to create and ft the proper prostheses, but also to act as the primary source of encouragement and enthusiasm for the patient. The pros-thetist must truly "be there," ensuring the ft and functional readiness of the prostheses and leading the patient forward with hope and confidence. Peer-to-peer support is also a key element of keeping the patient motivated and moving forward.1,2 Clapp's accomplishments as a prosthesis user have been the inspiration for many others to leave their wheelchairs behind. He provides the absolutely vital peer support that newer amputees need in order to believe it is possible to be a full-time bilateral transfemoral prosthesis user. Today, Clapp walks on his prostheses with microprocessor knees every day. "Many of the activities that I love to do would not be possible without prostheses," Clapp says. "Prostheses enable people to pursue the things that make their life richer" (figure 6). It is worth noting that two other bilateral transfemoral prosthesis users gave peer-to-peer support to Clapp after his injury—people who built his confidence in the possibility of a favorable prosthetic outcome.

Patients are ready to move on to the next phase when they are confidently and safely ambulating an entire day on short legs, with minimal or no need for crutches or canes.

Phase 3: Graduated Increases in Height

Patients who are ambulating well on shorties and training feet are ready to gradually increase their height. The first increase is usually about two inches and is accomplished by adding pylons between the sockets and the training feet. This increase usually requires patients to re-stabilize their balance and to expend more energy. A torque absorber can also be introduced to help reduce the shear forces of the residual limb moving against the wall of the socket.

At this phase, most patients are reaching an improved level of physical conditioning and their stamina is in creasing. This is critically important because walking on bilateral full-length legs expends 280 percent more energy than that required from a person who is not an amputee.8 Although continued physical therapy is still a good idea, what matters most is that the patient is using the shorties every day for walking and most other activities.

Reentering the community as a shorter person is also a necessary part of the patient's rehabilitation. It is not unusual for patients to resist venturing outside of their comfort zone while wearing shorties. Nonetheless, they should be strongly encouraged to go into public places such as restaurants, stores, and even into their workplace7 (figure 7). There is a definite psychological component of building confidence while adjusting to being seen by others as shorter or different. Patients must be reminded that every step they take in shorties brings them closer to attaining functional independence with full-length prostheses. With a little experience on short legs, most patients start to appreciate that they are able to be more independent than they were when using a wheelchair.

Figure 7: While patients are training on shorties, it is important for them to reintegrate into the larger community.

Susan Bailey, age 25, lost both of her legs above the knee in July of 2007 as a result of Escherechia coli bacteria leading to septic shock. She spent two months recuperating in the hospital, and when she was well enough, began trying to learn to walk on full-length legs. She relied on a wheelchair for mobility. In May of 2008, she had her first consultation with the authors, learned about the graduated approach to prosthetic fitting, and began walking on short legs. "With the shorties, I felt mobile again, like I could get up and go where I wanted to go, do what I needed to do," Bailey says. In June 2008, she attended the ACA conference and met bilateral transfemoral prosthesis user Heath Calhoun. Seeing him walk so well on full-length legs helped build Bailey's confidence that she could be a full-time prosthesis user (figure 8). They became friends, and later, Calhoun, along with another bilateral user, Staff Sgt. Roland Paquette, ret., came to her prosthetic clinic in Maryland for a peer-to-peer visit. Bailey experienced several graduated height increases over six months, and in November 2008, she successfully moved from short legs to full-length legs with microprocessor-controlled swing-and-stance hydraulic knees. Her husband and family provided exceptional support throughout the entire process, learning that sometimes the best thing to do was to step back and allow her to rediscover her independence. Following a graduated increase in height, patients must reestablish their balance and coordination. Height is then increased by an inch or more every few weeks. Without the added challenge of using two prosthetic knees, the patient slowly grows taller while becoming more confident and independent. After numerous height increases, some patients find that the extra-long pylon begins to get in the way in certain situations. In these cases, a pair of manual locking knees may be introduced to the short legs so patients can bend their legs when they need to sit down or get into a car. By the time patients are ready for the next phase, typically about 15 inches have been added to their height since they began wearing short legs.

Figure 8: Susan Bailey and Calhoun share peer-to-peer support at the ACA national conference.

Phase 4: Walking in Full-Length Legs with Knees and Prosthetic Feet

Bilateral transfemoral amputees and the prosthetists and therapists who work with them share a vision of complete mobility on two transfemoral prostheses—a vision that is much more likely to become a reality by following a graduated approach to prosthetic fitting. In this final phase, patients graduate to wearing full-length legs with microprocessor-controlled swing-and-stance hydraulic knees and energy-storing prosthetic feet.

The key components in the full-length prostheses are the microprocessor-controlled swing-and-stance hydraulic knees. These knees automatically adapt to the speed, length, and frequency of each step, resulting in the most natural gait pattern possible. This is particularly useful when the user encounters slopes, uneven surfaces, curbs, or stairs. Security is increased and the risk of falling is minimized with this specific knee.9 Patients react positively to the feeling of stability they experience with these knees, and the smooth, natural gait allows them to incorporate the prostheses as part of their total body image .10

The training feet are replaced with carbon-fiber energy-storing prosthetic feet. Slightly firmer feet are preferable. Softer feet will usually have a negative effect on knee flexion and make it difficult for bilateral users to initiate flexion of the knee when they want to sit down. It is also preferable to use standard pylons instead of pylons with torsion adapters. The use of torsion adapters adds additional weight to the distal end of the prostheses, and the added rotation at the feet requires additional energy expenditure.

Paquette, age 29, served as an Army Special Forces medic in Afghanistan. He lost his legs following an explosion in 2004. About nine months into his recovery at a military hospital, Paquette met bilateral transfemoral prosthetic user Clapp. Observing Clapp's high level of functioning, Paquette dedicated himself to learning to walk on full-length prostheses. After two years of struggling to walk and spending a lot of time in a wheelchair, Paquette saw a video of Heath Calhoun walking and playing golf while wearing his bilateral transfemoral prostheses. Paquette scheduled a consultation with the authors, who suggested he try walking on microprocessor-controlled swing-and-stance hydraulic knees. Paquette experienced an immediate improvement in both stability and gait, and with continued training, was able to become a full-time prosthetic user (figure 9). It is important to note that Paquette was in excellent physical condition and had been through a prosthetic rehabilitation program; these factors made it easier for him to quickly move forward once he was fitted with microprocessor-controlled swing-and-stance hydraulic knees.

Figure 9: With the help of prosthetist Chad Simpson, BOCP, LP, Staff Sgt. Roland Paquette, ret., gets acquainted with his microprocessor controlled swing-and-stance hydraulic knees.

Most full-time bilateral above-knee prosthesis users who have followed the outlined program will find that using full-length prostheses with microprocessor-controlled swing-and-stance hydraulic knees allows them the most function in an average day. It is important to note that "full-length" typically does not refer to the height the individuals were prior to their amputations. In fact, most users of full-length prostheses prefer to be a few inches shorter since they find it is easier to balance and to bend over to pick up objects from the floor. Most users also prefer smaller-sized feet that are more convenient when driving an unmodified vehicle. It is easier to safely move between the gas and brake pedal in that confined area.

Energy expenditure is increased when wearing full-length legs, but patients are usually prepared for that due to the conditioning and physical therapy they experienced in phases 2 and 3.8


Bilateral transfemoral amputees present complex challenges to prosthetists and the entire rehabilitation team. There are many vital components to achieving a positive prosthetic outcome: peer-to-peer support, a motivated patient who is in good physical shape, comfortable prosthetic sockets, healthy residual limbs, ongoing physical therapy, positive family support/involvement, and unwavering commitment from the prosthetist and rehabilitation team. The combination of all these factors can result in favorable outcomes for patients. The graduated approach to prosthetic fitting can also be applied to bilateral amputees who have a hip disarticulation on one side and a transfemoral amputation on the other side.

In these case studies, short legs have been presented as an integral training tool for phases 2 and 3 in the graduated rehabilitation process for bilateral above-knee prosthetic users. However, for most patients, shorties will continue to be useful in other situations throughout their lifetime. Sometimes it is simply easier and more practical for people to wear shorties, such as when they are doing chores at home, working in their garden, visiting the beach, or playing with their children. Shorties can also be more functional for some sports and recreational activities. Clapp has worn short legs for snow skiing, and Paquette wears shorties for swimming, replacing the standard feet with swim ankle/feet (figure 10).

Figure 10: Shorties can be useful in many activities and situations throughout life.

From a broader perspective, it is important for all members of the rehabilitation team to keep in mind that bilateral transfemoral amputees have usually experienced a traumatic event or illness that led to their amputations. Often, their condition is described as polytrauma—recovering from several serious injuries simultaneously. Learning to be a prosthesis user is just one of many challenges these patients face in reestablishing a state of physical and psychological health and wellness. As clinicians, we are asking a lot from people who are moving through various stages of the healing process. Expecting too much or demanding rigid compliance may only lengthen the rehabilitation process. All clinical efforts at creating a positive prosthetic outcome should be balanced with encouragement and patience.

While it is true that reaching the goal of becoming a full-time prosthesis user depends on the hard work and discipline of the patient, everyone on the care team must be accountable for his or her specific tasks—particularly the prosthetist. It is the pros-thetist's responsibility to ensure that the prostheses are completely functional during each phase of the graduated approach to fitting. The prosthetist must be proactively involved from start to finish and, in collaboration with the physical therapist, family, and peer visitors, build an enthusiastic support base.

In conclusion, the most convincing evidence of the effectiveness of a graduated approach to prosthetic fitting is seen in the outcomes of the patients themselves:

Paquette now relies on microprocessor-controlled prosthetic legs for his mobility. He is retired from the military and attending college to become a physician's assistant.

Bailey is now walking in full-length microprocessor-controlled legs and does not need crutches or canes. She is an active mother of two young children, the leader of her local amputee support group, and a national lecturer on the topic of recovering from limb loss.

Clapp pursues an active California lifestyle that includes body surfing, acting, and dating. He has participated in the national Endeavor Games for Athletes with Physical Disabilities, is a motivational speaker, and is certified as a peer visitor by the ACA. He is currently attending college.

Calhoun is training in Colorado for a position on the U.S. Paralympic Ski Team. He has competed in the Endeavor Games for Athletes with Physical Disabilities, enjoys playing golf, and drives a car without hand controls. He has not used a wheelchair since July 5, 2006.

Kevin Carroll, MS, C P, FAAOP, has been a practicing prosthetist for more than 30 years. He is the vice president of prosthetics for Hanger Prosthetics & Orthotics, Bethesda, Maryland. He presents scientific symposiums to healthcare professionals both nationally and internationally and specializes in managing the treatment of patients with complex cases. He is chair of the Lower Limb Prosthetics Society for the American Academy of Orthotists and Prosthetists.

Randy Richardson, RPA, is a licensed prosthetic assistant and has been with Hanger Prosthetics & Orthotics for more than 15 years. He specializes in working with bilateral above-knee prosthesis users to develop customized rehabilitation plans that enable them to be more independent and functional with prostheses.


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