Using the RCR method over the last few years has been a rewarding road of discovery. I have a better understanding of gait and normal anatomy. I have learned that the high tension cast in full extension gives me the best “snapshot” of the limb for comfort at midstance. I have also discovered that the problems I was having (distal tibia break down and alignment issues) have been cured with the RCR method. Patients love extra extension as well as flexion. I was surprised that even the relatively happy patients I already had were even happier when I switched them over to the RCR because of the increased freedom they felt. Lastly, I have been overwhelmed with the feedback from physical therapists saying that they are so impressed with the thoughtfulness of the design, and tell me they really never understood why there was a bar in the socket to begin with.
I believe that the RCR socket design and theory benefit ALL below-the-knee amputees. It is strange to think about not having a bar in a socket, but the time has come to say so long to the tradition and keep on developing socket designs that are relevant to the interface technology advances we now know. The RCR design and process is a systematic process which gives me confidence that I can make patients happy and comfortable in their prosthesis.
I recently documented a case where a patient had worn out his Ossur Comfort 3mm locking liner in the patellar tendon area. He also had a dark calloused spot on his patellar tendon. I put him into an RCR socket and the patient was thrilled. Over the course of 4 weeks, the dark callous turned lighter and eventually to normal, supple, non-calloused skin. His gait pattern was more normal, and he felt uninhibited around his knee because there was no material hindering full extension. The cosmesis was better because the socket was lower profile with no anterior gapping. Lastly, he was ecstatic that he was able to bend his leg up to about 110 degrees under him, which made it easier for him to get his 6’4” frame out of a low chair.
Two weeks after initial fitting
4 Weeks After Fitting
Dale’s conclusion is that with the advent of liners, I no longer need to load the patellar tendon. In fact, if I relieve the patellar tendon it is able to fully fire. Once I relieve the tendon, the quadriceps are allowed to gain strength and more normal extension is achieved at midstance. With these concepts, I, along with others, have hypothesized that this may be the missing link to a normal gait pattern rather than a “normal amputee gait pattern”.
Armed with my new-found knowledge, I went back at my office and tried it on my first, brave patient volunteer. The patient was in a socket with a very tight AP─so tight, that it actually caused a bulge in the popliteal area. He said he mostly just sat around because it was too painful to walk any distance. I casted him with the two-part high tension cast that the RCR mandates and had him weight bear through the cast. As he was putting weight through the cast, a smile crossed his face; this was the first time he was truly comfortable. I knew at that point not to do too much to the cast because I could mess up the fit. I followed the modifying instructions and enhanced my cast accordingly. The process did not take a great amount of time, and it gave me the confidence that I had a great fitting socket. The patient returned, and I was able to quickly align the prosthesis and allow the patient to leave on the copolymer check socket. I followed up with the patient in one week, and he had increased his activity level and kept telling me he was so amazed to not have pain. After this experience with the RCR, I knew that all my transtibial patients deserved to experience the comfort and freedom it offers.
At the end of 2008, I needed a few extra continuing ed credits, so I decided to take one of the inaugural RCR courses at Northwestern University organized by OPGA. Two days before I left for Chicago, OPGA called to let me know that one of their “hands on participants” had cancelled, and they were looking for a volunteer to take the spot. I must admit, my first thought was “no,” but I realized that the worst that could happen was to fail miserably so I took the spot and have not looked back since.
Dale Perkins, CPO with Rehab Systems in Boise, ID challenged my conventional thinking as well as historical perspective of transtibial socket design with the development of the RCR socket. The socket design is a result of challenges he experienced by putting a patellar bar in his own prosthetic socket. Dale underwent a closed femoral shortening on his limb to even his knee center, as well as to get a better foot under his socket. One of the unintended consequences of the femoral shortening was that the quadriceps were now long, which meant he had to undergo quadriceps strengthening. He had no issues in his socket at the time of the surgery, however, as he gained strength, he realized his patellar tendon was starting to bother him. He evaluated his socket and decided to remove the bar and essentially relieved the tendon. He found that once the tendon was relieved, he was able to continue strengthening his quadriceps. He also found that he was getting more extension than he had previously achieved with the bar. With the added normal extension moment he was getting at midstance, his gait pattern improved as well.
As a young, know-it-all prosthetist, I leaned over to my buddy and said in a sarcastic smug voice, “You’re kidding me right? These are the craziest trimlines for a BK I have ever seen; those shapes do not make any sense and would never work.” Over the next two years, however, I could not get my mind off of what I had seen, and I wanted to know more.
I enjoy reading a great deal of prosthetic historical literature, and I know that Charles Radcliffe, MS, ME pioneered many of the concepts that are still used today in below-the-knee prosthetics. His contributions are and continue to be extremely valuable to the field of prosthetics. I began to realize, however, that many of the theories behind the Patellar Tendon Bearing (PTB) prosthesis were actually created in the 1950’s─long before gel liners. Socket technology has not kept up with the designs and progression of new interface technology
Over the last few months I have been able to track what people are searching for and what people want to know. The RCR (now StabileFlex) socket design from Coyote Design has been one of the most searched for topics. I have used the Stabileflex socket design for over three years and help other prosthetists learn the design. I can honestly say that taking the RCR course was the best thing I did for the comfort of my patients. If you are a below-the-knee amputee and are interested in finding out more information please contact your prosthetist and I would be more than happy to share the information with him or her. Coyote Design has many avenues for prosthetists to learn the techniques of creating the design.
Mr. McMahon has generously given of his time to review the elan foot from Endolite. He feels as though it has greatly improved his ability to go up and down inclines but also given him a confidence that he has not had previously. Other feet he has tried have been the Trustep from College Park, Ceterus from Ossur, Echelon from Endolite, Proprio From Ossur, and now the elan.
Prosthetists will notice Mr. McMahon has an extremely strange alignment but it works for him. I will continue to make some minor changes to hone in his alignment but for the time being I can have been amazed at the increase in his activity level due to this foot.