Finger Amputees Return to Daily Activities with New Device

Daniel Didrick

Didrick Medical recently unveiled the new XFinger ®, which offers both aesthetic restoration and active function, adding a new level of expectation that will be required of artificial fingers for the 21st century.

Essentially, the X-Finger is the first activefunction artificial finger on the market that attaches to a finger amputees' residual limb. With this new device, amputees can independently gain control their artificial finger in the same manner as a real finger.

Currently, finger amputees have limited options because available finger prostheses have allowed for aesthetic restoration, but only limited function. The X-Finger replaces missing phalanges and allows the user to regain complete control of the jointed segments. The self-contained device is easy to don and doff by the user and can resolve a variety of hand restorative cases. Whether the amputee requires articulation of a single digit or an entire four-finger restoration, the X-Finger offers new hope for individuals who want complete independent active function in a self-contained device.

How It Works

The articulation of the X-Finger is completely controlled by the movement of the residual finger. By utilizing the residual finger as the controlling mechanism, the same cognitive process used to flex and extend the amputated finger now controls the X-Fingers' flexion/extension movements. When the user dons the X-Finger, the (extension) upward and (flexion) downward movement of the residual finger dictates the position of the replaced artificial phalanges. When the residual finger is extended upward, the artificial phalanges will also extend upward, causing the X-Finger to straighten as if the user were pointing. As the residual finger begins to flex or move downward, the artificial phalanges will also begin to flex, mimicking the prior finger's natural movements. For added realism, articulation of the X-Finger increases in proportion relative to the movement of the residual finger. This allows the user to pick up items by utilizing the tip of the X-Finger in combination with the thumb. The device allows the user to pinch objects as well as creating a fist when the user's thumb is not restricting the articulation of the device. This increasingly proportional method of articulation allows the user to grasp and pick up objects such as a cup of coffee or a business card in a more realistic manner than with current nonfunctioning artificial fingers.

All three sections representing the distal, middle, and proximal finger segments are adjustable for length, thus allowing the X-Finger to properly match the desired length of nearly any size finger. Once the desired length is calibrated, the device is inserted into a realistic silicone finger sheath, specially designed to bend while the device articulates. When the X-Finger is completely articulated, spaces in the device cause the silicone to fold and gently force the sheath to bend in a natural manner resembling an actual finger.

The X-Finger is attached to the hand utilizing a malleable wire form, which fits over the top and the underneath the metacarpal of the residual finger. The wire form can easily be manipulated to conform to the unique shape of the user's hand in an extremely low-profile manner. The X-Finger can be fitted in one sitting without the need of creating a positive hand cast.

Generic, Custom Sheaths

Included with the X-finger is a generic finger sheath fabricated from a supple silicone. The generic sheath permits the user to be fitted with the X-finger and sheath immediately upon shipment of the device. Thus, if a patient requests a custom sheath, he or she can wear the generic sheath until the custom sheath arrives.

If a custom finger sheath is requested, a positive cast of the patient's opposing hand is needed. The cast will then be scanned into a 3D computer image. The data image is mirrored and used to create a custom mold using rapid prototyping. This allows Didrick Medical to fabricate sheaths that identically match the amputated finger's shape and size. Further, Didrick Medical will supply the mold upon request in order for the practitioner to pour up multiple sheaths for those "do it yourselfers." Practitioners that have access to a patient's mold can quickly pour a new mold for users when needed.

Creating custom sheaths using a Didrick Medical mold does not require any heavy or expensive machinery. The silicone can be mixed in disposable cups with pigments, then inserted into a plastic syringe and simply injected into the intake hole of the mold. Once cured, the sheath is removed and ready for use. Depending on the level of color matching desired, there are extrinsic silicone paints available as well as sealants that set the coloration permitting the sheath to be washed with soap and water without losing the added color detail.

More Options for Practitioners

Studies have shown that approximately 60 percent of finger amputees who decided not to be fitted with a prosthetic finger did so because the fingers available did not articulate. Now with the X-Finger, anaplastologists, as well the O&P community, have an advantage when discussing options with their patients. Whether it's playing the piano or simply shaking someone's hand, the X-Finger can help restore numerous daily activities.

For a free clinical evaluation of a potential patient, simply fax a copy of your patient's hands to 888.569.1478 or e-mail a digital image to Didrick Medical will contact you with information regarding rehabilitation options utilizing the X-Finger.

Daniel "Dan" Didrick is president of Didrick Medical Inc., Naples, Florida.

This article has been reprinted with permission from O&p Edge and was previously published November 2005, O&P Edge.