Advanced Upper Limb Fitting Options For A Transhumeral Brachial Plexus Injury

William J. Sampson, CP and Bambi P. Lombardi, OTR/L
Sampson's O&P and Otto Bock Health Care
Schenectady, New York

Adult traumatic brachial plexus amputee injuries can be very complex in nature and can be a difficult prosthetic fit as well. Limited options are available due to lack of EMG capabilities and/or proximal strength for conventional function. This paper highlights an advanced prosthetic fitting option for a transhumeral brachial plexus amputee who underwent revisions to accommodate advanced technology for his upper limb fitting. A team approach incorporating therapy contributed to a successful fitting. This patient is a 28-year-old white male, who on July 7, 2005, collided with a truck while riding his motorcycle. He suffered extensive injuries that included fracturing his right leg tibia and femur and a right long transhumeral amputation with a brachial plexus injury. The patient was employed as a finisher at a paper mill. He is married and has 2 children, ages 2 and 4, both boys.

Upon evaluation, the patient had minimum soft touch sensation on the right transhumeral residual limb, was able to feel point pressure and was able to shrug his shoulders, but unable to move the arm at the glenohumeral joint. The different types of prosthetic options were reviewed with the patient with the idea that he would be treated more like a shoulder disarticulation. His shoulder needed to be encompassed for stability of the prosthesis. Body powered versus external power was discussed. The patient understood these options as well as some of the limiting factors, i.e., brachial plexus injury.

The patient was fit with a shrinker initially and seemed to tolerate it very well although he was extremely sensitive and in a lot of pain. Due to insufficient myo signals high up on the patient's back and anterior upper torso, it was recommended that he be fit with an electronic prosthesis using microprocessor switches. It was noted that due to the brachioplexus injury, the soft tissue on the humerus was subluxing, therefore causing redundant tissue distally. The patient saw a plastic surgeon to revise and tighten up the soft tissue around the humerus. The residual limb tissue was shortened by 3 1/2 to 4 inches in length which would assist with support and suspension of the prosthesis. The patient also underwent glenohumeral joint pinning to prevent subluxation of the humerus due to the complete brachial plexus injury. The joint was pinned in 15 degrees of abduction and 5 degrees of flexion for proper joint angle.

ADVANCED UPPER LIMB FITTING OPTIONS FOR A TRANSHUMERAL BRACHIAL PLEXUS INJURY

Discussions took place regarding some new surgical techniques. One was called targeted innervation, when a muscle is segmented with its own innervation. This is ideal for placement of several electrodes to operate a myoelectric prosthesis. The other technique was to do a titanium implant distally. This would flare the humerus over the distal aspect to allow suspension of the transhumeral socket. The patient decided on an externally powered prosthesis versus these surgical techniques.

A frame was designed around the transhumeral portion of the residual limb that would put surrounding pressure on the pressure transduscers. It was decided to use two pressure transducers to control the hand and rotator and one linear transducer to control the electric elbow, the DynamicArm from Otto Bock1. The patient was being seen by occupational therapy for general strengthening to accept the weight of the prosthesis.

A 3-day fitting session with the manufacturer of the electric elbow took place on July 25, 26, and 27, 2006. Fabrication took place during the course and the prosthesis was connected to a computer program via bluetooth to assess the function and make adjustments accordingly. The patient was able to simultaneously flex and extend the elbow while either rotating the wrist or opening and closing the hand/greifer. He did this by using the transducer for elbow control and the pressure transducers to function the rotator and the terminal device. He was very satisfied with the function and comfort of the prosthesis. Final delivery of the prosthesis took place on July, 31, 2006 and upon return visits, the patient reported wearing the prosthesis from morning until night. He found that the greifer terminal device was very useful in his activities of daily living. He stated that he was able to operate a 5-speed automobile using the prosthesis for changing gears. The patient did see a physical therapist for continued strengthening, controls training and functional training with the prosthesis.

Overall, this was a successful prosthetic fit for such a complex patient.