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Feature
A Novel Muscle Transfer for Independent
Digital Control of a Myoelectric Prosthesis:
The Starfish Procedure
By R. Glenn Gaston, MD, Chief of Hand Surgery Atrium Health, OrthoCarolina Hand and Upper Extremity Fellowship Director
Bryan J. Loeffler, MD, Clinical Faculty, OrthoCarolina Hand & Upper Extremity Fellowship, Atrium Health Department of
Orthopaedic Surgery
S ignificant technical advancements have occurred with development of a highly intuitive prosthesis since the interossei
upper extremity prosthetics in recent years, yet the goal naturally initiate finger flexion? Could this concept be applied at an
of achieving independent finger control has remained even more proximal level?
elusive given the limitations of the human-prosthesis
interface. Muscle contractions must generate a sufficient amplitude The Starfish Naming
of electric current to be detected by the surface electrodes which
power these prosthetics. However, in patients with partial or total First, a cadaveric study was undertaken to validate the proposed
hand amputations, the requisite number of functioning, detectable surgical technique of transposing the interossei while preserving the
muscles is lacking. As a result, control of current myoelectric neurovascular bundles. When all interossei, along with the thenar
hand prosthetics is very unnatural and non-intuitive and thus often and hypothenar musculature, were raised simultaneously with
abandoned by patients. the pedicles the resultant appearance was that of a starfish. This
appearance, coupled with the starfish’s unique ability to regenerate
The Starfish Hypothesis lost limbs, led us to term this surgery the Starfish procedure. In
this cadaveric study, all the hand intrinsic muscles were able to be
In patients with partial hand amputations, the interosseous muscles mobilized as a group while maintaining neurovascular pedicles up
often are still present and innervated, yet their deep position in the to the mid-forearm level.
hand prevents surface electrodes from detecting the signals generated
by their contractions. If these muscles could be transposed to the The Starfish Procedure
dorsum of the hand without injuring the associated Prior to embarking on this surgery, the viability and
neurovascular pedicles, could they serve functionality of the interosseous muscles must
as myoelectric signals for a patient be confirmed either in the operating room
with a partial hand amputation? at the time of initial injury or by EMG
If so, could this lead to the preoperatively.
8 | April 2018 • Mecklenburg Medicine
