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Orthopadie + Reha-Technik World Congress

Although there was nothing truly revolutionary in the realm of upper limb prostheses, a number of interesting improvements and advances were evident. By way of comparison, the Bundesfachschule [German P&O school] had a very nice display of historic devices, including some excellent examples of the leather arms from yesteryear.

Motion control from Utah unveiled their long-anticipated externally powered hand. Obviously based on the Bock design, it too has a two-speed transmission and uses a quick disconnect chassis that is directly compatible with the Bock wrist and electric rotator. But, the Motion Control Hand is designed to accept a wide range of batteries and voltages [from 6-12 volts] since it is used exclusively with the Utah microprocessor controls and electrodes. It uses the Centri inner hand and gloves, as well as custom silicone gloves from a variety of custom restoration companies.

The MC Hand also has a "quick release" built into the on/off switch that functions exactly like the lever on the Greifer. If the hand cannot be opened [for whatever reason] bumping the center of the dorsum of the hand firmly will mechanically disengage the fingers and they can then be opened passively. This is potentially advantageous when fitting very high level amputees whose small remnant muscle groups are often prone to fatigue. It will also make such ongoing tasks as protective glove removal and application easier.

Not to be outdone, Otto Bock unveiled a very clever variant on their externally powered hand with a much shorter chassis. This is a welcome addition to our armamentarium as it will make this technology available to a wider range of people with limb absences by decreasing the cosmetic penalty for the use of powered hands with long residuums.

It uses the familiar Bock electrodes, connectors, and both their NiCad and new Lithium Ion batteries. I am certain this will also be popular for wrist disarticulation applications due to the enhanced cosmesis that use of this hand will allow.

The recent advances in upper limb powered technology have left many practitioners a little uncomfortable because it is difficult to keep up with all these new options. To help allay these fears, the Bock booth showcased a TeleHelp kiosk demonstrating what will be available in the foreseeable future. Visitors could videoconference directly with the Vienna research lab and see for themselves that it is now technically feasible to have the experts who designed the MyoBock hands perform remote electronic troubleshooting analysis, adjustments, programming, and even EMG evaluations. As the field moves toward more and more microprocessor-controlled components, such remote technical assistance will become increasingly important.

Much as today's automobile "tells" the service technician what needs to be fixed, tomorrow's powered limbs will use similar smart technology to increase clinical reliability for our patients. It will be much more convenient to plug the arm into an Internet connection and have diagnostic software confirm that there is a faulty connection in the ground cable from the battery than it is today, when we must tear down the arm and manually test all connections.

Finally, prosthetist Hans Oppel from Vienna presented a lecture about a very intriguing prototype for a prefabricated micro-shoulder saddle that he has used successfully to suspend a transhumeral prosthesis. It appears primarily suitable for mid-shaft and longer amputations, but it allows fitting of a "harness-free" TH prosthesis.

The mini-saddle is lined with very "sticky" gel sheet material that provides comfortable and secure suspension. The "legs" are anchored to the anterior and posterior trim lines of the sub-deltoid socket. Some clever interaction between the articulations permits unrestricted shoulder extension and flexion as well as abduction, adduction and scapular motions.

I saw the patient who is wearing the prototype and verified that the suspension is surprisingly secure, yet it is very easy for the patient to don and doff. Although it is possible to combine this micro-saddle with a suction socket, this patient was wearing a conventional flexible socket with a distal pull hole. So, it was clear that the sole suspension came from the micro-saddle.

If this develops into a commercial product, it would provide an alternative to silicone sleeve suspensions or suction sockets when this population needed self-suspending prostheses.