# Backslab/Cast Choice

## Overview

Treating fractures non-surgically requires choice of an immobilising device, depending on the type of injury. In general, acute injuries benefit from a backslab (splint), which allows for swelling while stabilising a joint or fracture, which is replaced later with a more immobilising cast.

## Upper limb

### Phalangeal fractures

Remove splints/casts after 4-6 weeks.

Refer all intra-articular fractures or unstable fractures.

### Metacarpal fractures

1. Thumb (digit 1): thumb spica splint.
2. Fingers (digits 2-5): dorsal/volar forearm splint with buddy taping.
3. Intraarticular or unstable fractures: refer.

Remove splints after 4-6 weeks.

### Carpal fractures

1. Undisplaced carpal fractures: below elbow splint extended to the metacarpal heads for 6 weeks and refer to physio and OT.
2. Displaced, intraarticular or unstable fractures, and all lunate and scaphoid fractures: refer due to high risk of nonunion.

### Radial & ulnar fractures

### Humeral fractures

## Lower limb

### Tarsal, metatarsal & phalangeal fractures

1. Distal metatarsal fractures: below knee cast/splint for 4-6 weeks.
2. Phalangeal fractures: buddy strapping to the adjacent uninjured toe.
3. Undisplaced tarsal & metatarsal shaft fractures: below knee cast/splint for 4-6 weeks.
4. Intra-articular or unstable fractures: refer. Obtain a standing X-ray to assess for instability and displacement of tarsal or tarso-metatarsal fractures and dislocations to exclude a Lisfranc injury.

### Tibial & fibular fractures

1. Ankle fractures: below knee cast for 6-8 weeks.
2. Fibular fractures: below knee splint for 6-8 weeks.
3. Tibial or tibia & fibula fractures, use an above knee cast/splint for 6-8 weeks and then convert to a below knee cast, patella bearing for another 6-8 weeks.
4. Intra-articular, unstable or displaced fractures: refer.

## References

1. Boyd AS, Benjamin HJ, Asplund C. Splints and Casts: Indications and Methods. Am Fam Physician. 2009 Sep 1;80(5):491-499. Available from: https://www.aafp.org/afp/2009/0901/p491.html
2. Held M. Orthopaedics for Primary Health Care. Available from: https://www.ortho.capetown/primary-care-orthopaedics