George P. Nanos

First-in-man demonstration of a fully implanted myoelectric sensors system to control an advanced electromechanical prosthetic hand.

BACKGROUND Advanced motorized prosthetic devices are currently controlled by EMG signals generated by residual muscles and recorded by surface electrodes on the skin. These surface recordings are often inconsistent and unreliable, leading to high prosthetic abandonment rates for individuals with upper limb amputation. Surface electrodes are limited because of poor skin contact, socket rotation, residual limb sweating, and their ability to only record signals from superficial muscles, whose function frequently does not relate to the intended prosthetic function. More sophisticated prosthetic devices require a stable and reliable interface between the user and robotic hand to improve upper limb prosthetic function. NEW METHOD Implantable Myoelectric Sensors (IMES(®)) are small electrodes intended to detect and wirelessly transmit EMG signals to an electromechanical prosthetic hand via an electro-magnetic coil built into the prosthetic socket. This system is designed to simultaneously capture EMG signals from multiple residual limb muscles, allowing the natural control of multiple degrees of freedom simultaneously. RESULTS We report the status of the first FDA-approved clinical trial of the IMES(®) System. This study is currently in progress, limiting reporting to only preliminary results. COMPARISON WITH EXISTING METHODS Our first subject has reported the ability to accomplish a greater variety and complexity of tasks in his everyday life compared to what could be achieved with his previous myoelectric prosthesis. CONCLUSION The interim results of this study indicate the feasibility of utilizing IMES(®) technology to reliably sense and wirelessly transmit EMG signals from residual muscles to intuitively control a three degree-of-freedom prosthetic arm.

New options for vascularized bone reconstruction in the upper extremity

Originally described in the 1970s, vascularized bone grafting has become a critical component in the treatment of bony defects and non-unions. Although well established in the lower extremity, recent years have seen many novel techniques described to treat a variety of challenging upper extremity pathologies. Here the authors review the use of different techniques of vascularized bone grafts for the upper extremity bone pathologies. The vascularized fibula remains the gold standard for the treatment of large bone defects of the humerus and forearm, while also playing a role in carpal reconstruction; however, two other important options for larger defects include the vascularized scapula graft and the Capanna technique. Smaller upper extremity bone defects and non-unions can be treated with the medial femoral condyle (MFC) free flap or a vascularized rib transfer. In carpal non-unions, both pedicled distal radius flaps and free MFC flaps are viable options. Finally, in skeletally immature patients, vascularized fibular head epiphyseal transfer can provide growth potential in addition to skeletal reconstruction.

Targeted Muscle Reinnervation for Transradial Amputation: Description of Operative Technique.

Targeted muscle reinnervation (TMR) is a revolutionary surgical technique that, together with advances in upper extremity prostheses and advanced neuromuscular pattern recognition, allows intuitive and coordinated control in multiple planes of motion for shoulder disarticulation and transhumeral amputees. TMR also may provide improvement in neuroma-related pain and may represent an opportunity for sensory reinnervation as advances in prostheses and haptic feedback progress. Although most commonly utilized following shoulder disarticulation and transhumeral amputations, TMR techniques also represent an exciting opportunity for improvement in integrated prosthesis control and neuroma-related pain improvement in patients with transradial amputations. As there are no detailed descriptions of this technique in the literature to date, we provide our surgical technique for TMR in transradial amputations.

Ballistic trauma: lessons learned from iraq and afghanistan.

Management of upper extremity injuries secondary to ballistic and blast trauma can lead to challenging problems for the reconstructive surgeon. Given the recent conflicts in Iraq and Afghanistan, advancements in combat-casualty care, combined with a high-volume experience in the treatment of ballistic injuries, has led to continued advancements in the treatment of the severely injured upper extremity. There are several lessons learned that are translatable to civilian trauma centers and future conflicts. In this article, the authors provide an overview of the physics of ballistic injuries and principles in the management of such injuries through experience gained from military involvement in Iraq and Afghanistan.

Initial management of upper extremity war injuries

Upper extremity war injuries are complex wounds that include a combination of bone, soft-tissue, and vascular injury, and nerve loss. Treatment begins in theater with initial wound care and provisional skeletal stabilization. Once in the continental United States at a tertiary-care facility, the wounds are further debrided, and definitive treatment is initiated. Definitive treatment involves a multidisciplinary approach to treat all associated injuries. After serial debridement and irrigation to remove all devitalized tissue and contamination, a coordinated plan is made for skeletal stabilization and definitive closure or soft-tissue coverage. Options for skeletal fixation include open reduction internal fixation, external fixation, intramedullary nailing, and cement spacer placement with delayed bone grafting for segmental bone loss. Soft-tissue coverage options include delayed primary closure, dermal substitutes, skin grafting, rotational flaps, pedicled flaps, and free flaps. Treatment decisions are dictated by injury location, size of wounds, and donor site availability. Associated nerve injuries often present with large segmental defects and cannot be repaired acutely. Treatment requires delayed autograft reconstruction, with or without nerve conduits.

Incidence and Risk Factors for Volar Wrist Ganglia in the U.S. Military and Civilian Populations

PURPOSE To identify the incidence and demographic factors associated with volar wrist ganglia in both military and civilian beneficiary populations. METHODS The U.S. Department of Defense Management Analysis and Reporting Tool (M2) accesses a comprehensive database of all health care visits by military personnel and their dependents. Because there is no specific code for ganglions of the wrist, the database was searched for all military personnel and civilian beneficiaries with an International Classification of Diseases, 9th Revision, diagnosis of 727.41 (ganglion of a joint) or 727.43 (ganglion, unspecified location) between 2009 and 2014. Two random samples of 1000 patients were selected from both the military and the civilian beneficiary cohorts, and their electronic medical records were examined to identify those with volar wrist ganglia. The proportion of volar wrist ganglia was then applied to the overall population data to estimate the total incidence with a 95% confidence interval and 5% margin of error. Unadjusted incidence rates and adjusted incidence rate ratios were determined using Poisson regression, controlling for age, sex, branch of military service, and military seniority. RESULTS The unadjusted incidence of volar wrist ganglia is 3.72 per 10,000 person-years (0.04%/y) in female civilian beneficiaries, 1.04 per 10,000 person-years (0.01%/y) in male civilian beneficiaries, 7.98 per 10,000 person-years (0.08%/y) in female military personnel, and 3.73 per 10,000 person-years (0.04%/y) in male military personnel. When controlled for age, military personnel have a 2.5-times increased rate of volar wrist ganglia, and women have a 2.3-times increased rate. In the military cohort, female sex, branch of service, and seniority were significantly associated with the diagnosis of a volar wrist ganglion when controlled for age. In the civilian beneficiary cohort, only female sex was significant. CONCLUSIONS Military service members have higher rates of volar wrist ganglia diagnoses than their age- and sex-matched civilian counterparts. Women are significantly more likely to be diagnosed with a volar wrist ganglion, regardless of age or military status. CLINICAL RELEVANCE The epidemiology of volar wrist ganglia is poorly defined, and few studies have firmly defined demographic factors associated with the diagnosis. We provide the overall incidence rate of the diagnosis and report a significant association with female sex even when controlled for age.

Arm and Shoulder Injuries

War-related injuries to the brachium and shoulder frequently involve penetrating injuries from gunshot wounds and blast fragments, as well as crush injuries from vehicular rollover and building collapse. Concomitant fractures, neurovascular injuries, defects in bone and soft tissues, and additional associated non-musculoskeletal injuries further complicate these challenging problems. A clear understanding of anatomy and a systematic approach to evaluation and management of the severely injured brachium and shoulder are essential to achieving the best result. A multidisciplinary approach will greatly assist the orthopedic surgeon, choosing interventions based on sound orthopedic principles while optimizing the physical and psychological health of the individual.