Cast Modifications

9 Cast Modifications

Cut down the side with a utility knife or cast saw, taking care not to damage the cast. Strip the wrap and re-mark the landmarks that have transferred from the wrap to the mold
Measure circumferences, length and medio-lateral dimensions on the model and compare them to your recorded measurements.

Medial and Lateral Trimlines

Posterior Trimline

Anterior Trimline

Finger width proximal to bony edge of epicondyles.

Encompass the epicondyle at the level of the P-M-L with enough of a brim to flare out of the soft tissue.

Lateral: relief for the humerus in the ROM (“fan relief”)

Standard: 25mm proximal

2.5-5cm proximal to edge of olecranon, capture the triceps bar

Encompass the olecranon

Compress the triceps tendon

Relief for bony pressure on the posterior humeral epicondyles

Medium length limbs: 10mm distal to cubital fold

• short limbs closer to cubital fold

• longer limbs ok to allow room (distal to cubital fold)

Clearance for biceps tendon.

Remove plaster from area superior to the epicondyles to gain medio-lateral stabilization
- 6mm proximal to the epicondyles, but allow channel for donning/doffing
- 3mm proximal to the olecranon
- Anterior trimline
Use a surform to shape and smooth the model

Location	Add plaster
Antecubital bulge	Apex of belly is 1.25-2cm distal to trimline Depends on length of limb
Epicondyles	3mm and lateral relief, fan shape
Olecranon	3mm
Distal end	6mm
Fill holes over bony prominences

Double check for the following:
- a) pressure distribution to secure the socket at necessary locations (i.e., force couples)
- b) ML dimension at epicondyles to ensure donning/doffing ability and
  c) Smooth transition, especially between the head of the radius and the lateral epicondyle and the olecranon and medial epicondyle.
Smooth the model with sanding screen to remove irregularities.
Draw trimlines again.