Patient Presentation:
K presents with an undiagnosed neuromuscular disorder leading to left arm dystonia; which for her has caused a persistent palm down (pronated) position while at rest. Due to the intensity and long term nature of this position, she has lost range of motion in the palm up (supination) direction and feels that her wrist is unstable. K also is unable to maintain control of the forearm’s rotational position during elbow flexion or extension which results in the palm dropping into pronation when she moves. This makes using the arm for functional tasks or holding things quite difficult unless they need a palm down position.
Patient Goals
K wants to improve her ability to supinate in order to broaden the tasks she is capable of performing. She also wants to be able to keep her palm in a useful position while flexing or extending her elbow to better use the arm for tasks and carrying things. She wants to do more cycling which requires wrist stabilization and has dreams of participating in Ninja Warrior style obstacle courses.
Clinical requirements
To meet these goals the orthosis will need to allow full range of motion of forearm rotation which is nearly 180 degrees. The orthosis will also need to be able to comfortably support her wrist and keep the palm from dropping down into pronation during the activation of her elbow. It will also need to be durable enough and low profile enough to hold up to her active lifestyle goals.
Orthosis & treatment design:
A wrist hand orthosis will not succeed in maintaining pronation or supination control as it will not be able to prevent slipping of rotational position; therefore an elbow orthosis was required with hand control. The elbow orthosis will need a full range of motion in two different planes (flexion/extension & pronation/supination) to succeed; a requirement which has not been successfully accomplished before due to the fabrication difficulties.
To address this clinical challenge we used additive design and 3D printing techniques to create a three part elbow orthosis with a rotational channel in the forearm section. A locking mechanism was utilized to allow K to manually lock out the forearm’s position for both stretching and functional tasks. The orthosis was set to stop at the palmar crease to provide a balance between wrist support without compromising finger and thumb dexterity.
Impression:
K has been able to comfortably wear the orthosis for both stretching and functional tasks. She reports that the elbow is not impeded and the wrist is stably held without discomfort for functional tasks.
Additive techniques have offered an opportunity for this orthotic treatment to be attempted successfully. Being able to produce orthoses with control for two separate planes of motion is a very exciting window into the opportunities that additive design and 3D printing are able to offer orthotists.
