
POSI Z-SPLINT (POSITION OF SAFE IMMOBILISATION SPLINT)
- The Z-splint is the Position of Safe Immobilisation, as this allows collateral ligaments to be positioned on a stretch, thereby limiting tightness of these ligaments.
- The wrist is 30° extended, MCP 70°–90° flexed and IP’s extended.
- Use this splint in any hand or finger injury that needs to be immobilised.
- Use this splint to immobilise infective conditions.
Steps of applying a POSI Z-splint
- It is easiest if the patient lies on their back and their hand is fully supinated facing to the roof.
- Wrap the whole forearm to the fingers with velband or webril.
- Use 2100mm gypsona casts and make it the length of two hand spans.
- Use a buttress under the distal radius to allow the wrist to fall back in 30° extension.
- Apply the cast to the volar (palmar) side of the hand and ensure the cast is long enough to support the full length of the middle finger.
- Work the cast into the depth of palm and try to obtain maximum MCP flexion whilst keeping the fingers straight.
- Ensure the cast does not limit elbow flexion and extension.
- Wrap this up with a bandage (elastoform).
- It is preferable to see the fingertips

