4C. Setup for Rigid Hinges

Flexible hinges

1. Remove the PVC pipe. Keep the PVC pipe, wrist and TD for use at the next appointment.
2. Remark todo modifications on the inside of the socket with black sharpie (these will transfer to the plaster mold).
3. Use duct tape to skirt socket 3-5 cm proximal to your ideal proximal trimlines. Ensure that the proximal edge of the duct tape is perpendicular to the pipe.

Rigid hinges

Use the elbow hinge spacer to align the elbow joints. Notice the parallel surfaces of the faces of the brass spacer (outside surfaces). After filling the socket with plaster, you will match these surfaces with the inside flat edge of the rigid joints. Follow the following steps:

1. Remove the PVC pipe. Keep the PVC pipe, wrist and TD for use at the next appointment.
2. Remark todo modifications on the inside of the socket with black sharpie (these will transfer to the plaster mold).
3. Double check the alignment by placing your fingers on the joint center and looking at their alignment.
4. Drill a pilot hole at the elbow joint center with a size #19 bit. The wall of the check socket is usually on an angle to the face of the spacer. When drilling, the bit should be directed toward the opposite hole.
5. Determine the elbow joint clearance.
   1. The finished device should have 2-3 mm clearance between each epicondyle and the corresponding metal joint when elbow is flexed 90 degrees. In the presence of fleshy residual limbs, the metal should not touch the skin.
   2. Adjust the spacer to the length between the faces of the brass spacer matches this final diameter. You will use the face of the brass spacer (flat ends) to square your joints after filling the socket with plaster.

6. 

   Check the fit of the elbow hinge spacer in the socket.

   1. If the spacer will fit through both sides of the socket (ideal), drill a ½” drill bit to fit the spacer through the socket.
   2. If the spacer is not long enough to fit through the socket, place the screws through the pilot holes to secure the spacer in place.
   3. The spacer must be secured in the socket before filling with plaster.
7. Cover the spacer with lots of Vaseline, a parting agent to help you remove it from the mold later.
8. Use duct tape to skirt socket 3 cm proximal to the proximal edge of the joint spacer. Ensure that the proximal edge of the duct tape is perpendicular to the pipe.