'Bionic Hand' Boosts Function After Brachial Plexus Injury
Posted: Wed Feb 25, 2015 2:47 am
http://www.medpagetoday.com/Surgery/Orthopedics/50178
Bionic Hand Boosts Function After Brachial Plexus Injury
— Treatment begins with elective amputation and includes selective nerve and muscle transfer.
SURGERY 02.24.2015
Bionic reconstruction of the hand through a myoelectric prosthesis was
associated with better hand function and less pain for three patients in
Austria who suffered global brachial plexus injuries.
After 3 months, patients' mean Action Research Arm Test (ARAT) scores
increased from 5.3 to 30.7 out of a possible 57 points, while mean
Southampton Hand Assessment Procedure (SHAP) scores improved from 9.3
to 65.3 out of a possible 100 points, according to Oskar C. Aszmann, MD, of
the Christian Laboratory for Restoration of Extremity Function at the
Medical University of Vienna, and colleagues.
Mean Disabilities of Arm, Shoulder and Hand (DASH) scores improved from
46.5 to 11.7 where 0 indicates the best hand function, they wrote in Lancet.
Mean ARAT and SHARP scores also exhibited improvements even prior to
the patient's final prosthetic fitting. During "intermediary testing with the
hybrid hand," mean ARAT scores rose to 18.6 compared with 5.3 at baseline,
while mean SHAP scores were 23.3 with the hybrid compared with 9.3 at
baseline. There also were improvements in SF-36 outcomes for physical
functioning and mental health, the authors wrote.
After the final treatment, patients were able to wear their prosthetic hands
for 8 to 12 hours a day and reported the ability to once again do bimanual
tasks. The study also showed that two out of three patients reported an
improvement in mental health (the third showed no change) as a result of
this improved function.
Co-author Aidan D. Roche, MBBS, PhD, also of the Medical University in
Vienna, told MedPage Today that traditional reconstructive techniques are
only able to restore hand and elbow function, but the patient may be left
with a useless hand.
"The study was prompted by lack of techniques to restore hand function in
patients with lower root brachial plexus injuries," he said. "Advances in
surgical techniques, such as selective nerve transfers, to improve prosthetic
control for existing amputees provided evidence that better hand control
could be achieved using prostheses."
Brian Carlsen, MD, a hand surgeon at Mayo Clinic in Rochester, Minn., who
was not involved in the current study, added that these kinds of injuries can
be a tremendous cost to society, as well as being devastating for the
patient.
"The study represents a nice illustration of how technology can be enhanced"The study represents a nice illustration of how technology can be enhanced
with surgery to improve patient outcomes in regards to function and
independence," he said.
The researchers examined PubMed, Cochrane Databases, and Google
Scholar for meta-analyses, systematic reviews and research articles about
arm reconstruction after global brachial plexus injury, and concluded that a
new approach to restoring hand function was necessary for patients with
"no further reconstructive options available."
From April 2011 to May 2014, three patients were selected who had
sustained global brachial plexus injury, including lower root avulsion, and
had previously been treated with primary brachial plexus reconstruction.
Criteria for selecting patients included "attempted biological reconstruction
procedures, resulting in a stiff, insensate, intrinsic minus hand," as well as
patients who experienced "great psychological harm as the result of injury."
Patients with a "useful sensation" in their hand or an "inability to lift the
forearm against resistance (<M4)" were excluded from the study.
The treatment was performed in two stages. The authors first identified
and created "useful electromyographic signals for prosthetic control." Then,
they amputated the hand and replaced it with a mechatronic prosthesis.
Patients then underwent a rehabilitation program and were fitted with their
final prosthesis as early as 6 weeks after amputation.
Andrew Schwartz, PhD, a professor of neurobiology at the University of
Pittsburgh School of Medicine, said that amputating the patient's hand as
part of the treatment program was novel. "It has been discussed in the
plastic surgery community as an alternative to hand transplant, but this is
the first report I know of, in which it was carried out," he said.
A study limitation was its short duration, wrote Simon Kay, MD, and Daniel
Wilks, from Leeds Teaching Hospitals in Leeds, England, in an accompanying
editorial. The final verdict on the procedure will depend on long-termeditorial. The final verdict on the procedure will depend on long-term
outcomes, they said, adding that compliance declines over time with all
prostheses.
Kay and Wilks also pointed out that "the two enormous repertoires of the
human motor cortex and the human hand will never be adequately
connected through a choke point of a few sensing channels."
Steven Beldner, MD, co-director of the Hand Surgery Center in New York
City, noted that the Aszmann's group did not compare results from
currently accepted techniques in reconstruction.
"It does not answer the question: Is the large amount of money and time in
patient training to learn how to use these devices and equipment better
than the existing treatments such as nerve, muscle, and tendon transfers?"
he said.
While Carlsen pointed out this type of injury affects a relatively small
number of patients, he still saw potential for this study in the field of
prosthetics. "This is an important illustration of what is possible when all of
our available 'tools' are used together -- surgery, prosthetics, engineering,
and robotics," he said.
Roche said that the technique could be applied to patients with different
injuries that lead to a functionless hand, such as crush injuries or mangled
limbs from industrial accidents.
"We would like to see significant steps made towards providing sensation to
prosthetic users," he said.
The study was funded by the Christian Doppler Research Foundation
of the Austrian Council for Research and Technology Development,
Austrian Federal Ministry of Science, Research and Economy, and
European Research Council Advanced Grant DEMOVE.HRT Preserves Joint Implants in
Women
— A 40% decrease in revision surgery for
hips/knees with hormone replacement.
European Research Council Advanced Grant DEMOVE.
Aszmann and co-authors disclosed no relevant relationships with
industry.
Kay and Wilks disclosed no relevant relationships with industry.
Reviewed by Robert Jasmer, MD Associate
Clinical Professor of Medicine, University
of California, San Francisco
Primary Source
The Lancet
Source Reference: Aszmann OC, et al "Bionic reconstruction to restore hand function after brachial
plexus injury: a case series of three patients" The Lancet 2015; DOI: 10.1016/S0140/6736(14)617761.
Secondary Source
The Lancet
Source Reference: Kay S, Wilks D "Bionic hand transplantation: linking the cortex to the hand" The
Lancet 2015;
