Locking liner Carbon Fiber transtibial endoskeletal prosthesis

It is funny that the more comfortable I get with steps in the process the less pictures I take along the way. As I now look through the pictures I have I realize that many steps in the process were not documented. The plasterwork was largely omitted but it is very important to get the dummy lock lined up properly. Lets start today off with the drape formed check socket.

 This took some work. I began by attaching the bulldog locking liner dummy to my smoothed plaster model. This required that I drill into the plaster model enough to have the main bolt deep into the plaster.

 I then heated the polyethylene plastic in our PDQ infrared oven until it was ready to pull and drape over the plaster model.

 I then removed the dummy and put the definitive locking mechanism into the bottom of the socket. Then I attached the pyramid component, pylon and foot. I marked my LOP and flexion and adduction lines.

 I have bench aligned the prosthesis now and am ready to pass it off to be dynamically aligned.

 After the dynamic alignment I need to capture the alignment and laminate, after which I would then transfer the alignment to the definitive socket.

 Here is my carbon fiber i-beam lamination lay up. It consisted of a layer of carbon fiber then a patch of carbon fiber for thickness over the circular dummy lock then three layers of nyglass then the final carbon fiber sleeve,

 Letting the AME resin soak into the carbon fiber lay up. Nice to use black pigment as well to keep things nice and dark.

 Here it is all hardened and ready to be trimmed out.

 Clay said that carbon fiber dust was not very friendly. I decided to fool around a little and dress like a wild west bandit. Needless to say I got made fun of. I however did not itch at all after trimming the socket out.

 That is thing of beauty. I love the look of carbon fiber. The lamination is thin and very strong.

 Here it is all assembled.

 I thought that it would be fun to set my foot next to the prosthetic device that I just made.

 Now it is all assembled and loctited so it is ready to go out the door.

The completed device with the liner installed. The liner would normally be rolled onto the patient before they stepped into the prosthesis. Because of the nature of the carbon fiber and the thinness of the lamination the dynamic alignment is done over weeks in a real setting. It seems to me that these sockets have no real wiggle room for after the fact modifications to relieve pressure points. They make great sockets for a patient that will not atrophy much more. 

I really enjoyed making this device and hope to work with carbon fiber more in the field.