Dear Pain Matters blog readers,
A recent article in Science Translational Medicine journal by Max Ortiz-Catalan et al (8 October 2014) offers hope that Phantom Limb Pain may be reduced in some patients with Phantom Limb Pain. Specifically, Phantom Limb Pain was reduced by 40% in a patient following implantation of an osseointegrated (i.e. bone-anchored) prosthetic arm. (His arm was amputated above the elbow.)
A small fixture was internally anchored into the bone at the stump, while an external anchor was added to connect the prosthesis to the stump. Additionally, seven (7) electrodes were implanted into the stump’s connective tissue including muscles and peripheral nerves (to transmit electrical information between the brain and skeletal muscles for prosthetic arm movement).
Not only did this osseointegrated prosthetic arm (with an implanted neuromuscular interface; ie 7 electrodes) facilitate a greater range of motion than a traditional prosthetic, but these 7 implanted electrodes also enabled improved electrical communication between the brain and muscles. This leads to more control of the osseointegrated prosthetic arm including improved manipulation of very small items. (Currently, electrodes are externally placed on top of the skin in some patients.)
Electrical pulses were sent to the stump’s muscles and peripheral nerves via the 7 implanted electrodes, enabling simulation of sensation in the amputated arm that was perceived as a ‘pulsing’ or ‘tingling’ sensation sensation by the patient (depending on pulse intensity).
Now here is the interesting part regarding the patient’s Phantom Limb Pain: The osseointegrated prosthetic arm also resulted in a 40% reduction in the patients’ Phantom Limb Pain. Thus, a bone-anchored prosthetic arm may offer a novel treatment option that may significantly reduce Phantom Limb Pain in some patients with intractable Phantom Limb Pain.
For more on Bionic Limb expert, Max Ortiz-Catalan, please refer to: http://www.tedxgoteborg.com/portfolio/max-ortiz-catalan-scientist-of-bionic-limbs/
Further references (NB This is not a complete list of References):
(1) Ortiz-Catalan M, Hakansson B, Branemark R; An Osseointegrated Human-Machine Gateway for Long-Term Sensory Feedback and Motor Control of Artificial Limbs; Science Translational Medicine, 2014; 6 (257): 257re6 DOI: 10.1126/scitranslmed.3008933 http://stm.sciencemag.org/content/6/257/257re6
(2) Chalmers University of Technology. Mind-Controlled Prosthetic Arms that Work in Daily Life are Now a Reality; ScienceDaily, 8 October 2014 http://www.sciencedaily.com/releases/2014/10/141008153616.htm
(3) Hiscott R; One Step Closer to Bionic Limbs: Researchers Simulate Sensation in Prosthetic Arms; 8 October 2014 http://journals.lww.com/neurotodayonline/blog/breakingnews/pages/post.aspx?PostID=385