# Casting, Splinting, and Traction: Fundamental Techniques

## Introduction

Casting, splinting, and traction are foundational skills in orthopedic surgery that remain indispensable despite advances in surgical fixation. These non-operative techniques serve as primary treatment for many fractures, provide temporary stabilization before definitive surgery, and play a critical role in postoperative management. Mastery of these techniques requires understanding the biomechanical principles behind immobilization, the materials available, and the potential complications that arise from improper application.

## Casting Techniques

### Indications for Casting

Casting is used as **definitive treatment** of stable, minimally displaced fractures (such as distal radius and tibial shaft fractures in select patients), for post-reduction immobilization of fractures amenable to closed management, for pediatric fractures with significant remodeling potential, and for postoperative protection following tendon repair or ligament reconstruction.

### Materials and Application

**Plaster of Paris** features an exothermic setting reaction, molds well, and is radiolucent, making it ideal for initial application and molding. **Fiberglass** is lighter, stronger, and available in water-resistant options, though it is less moldable than plaster. Proper application requires smooth, wrinkle-free **stockinette** and adequate **cotton padding** (typically 2-4 layers). Extra padding is applied over bony prominences including the **malleoli**, **olecranon**, and **fibular head**. Water temperature for dipping should be lukewarm (24-26 degrees Celsius) to allow adequate working time; hotter water accelerates setting and increases thermal injury risk.

### Principles of Three-Point Molding

**Three-point fixation** creates a force system that maintains fracture reduction. The interosseous mold for forearm fractures separates the radius and ulna to prevent malrotation. The cast index (ratio of sagittal to coronal diameter) should approach 0.7 for optimal distal radius fracture control. Overly tight molding risks pressure sores, while insufficient molding results in loss of reduction.

![Diagram illustrating the three-point molding technique for a short arm cast applied to a distal radius fracture](three-point-molding-cast.jpg)

## Splinting Techniques

### Indications for Splinting

Splinting is indicated for **acute injuries** with anticipated swelling where circumferential casting would be dangerous, for temporary stabilization prior to definitive surgical management, for injuries requiring frequent wound inspection, and for patients with soft tissue compromise or burns overlying the fracture.

### Common Splint Types

| Splint | Indication | Position | Key Feature |
|--------|-----------|----------|-------------|
| Sugar-tong (UE) | Distal radius, forearm fractures | Neutral forearm rotation | Prevents pronation/supination |
| Posterior long arm | Elbow injuries | 90° flexion | Elbow immobilization |
| Ulnar gutter | 4th/5th metacarpal, phalangeal fractures | MCP 70-90° flexion, IP extended | Intrinsic-plus position |
| Thumb spica | Scaphoid, 1st metacarpal injuries | Thumb in abduction | Includes thumb to IP joint |
| Posterior ankle | Ankle fractures, Achilles injuries | Neutral dorsiflexion | Prevents equinus |
| Bulky Jones | Knee injuries, post-op | Slight flexion | Maximum swelling control |

The **sugar-tong splint (upper extremity)** prevents forearm rotation and is used for distal radius and forearm fractures. The **posterior long arm splint** provides elbow immobilization at 90 degrees of flexion. The **ulnar gutter splint** is used for fourth and fifth metacarpal and phalangeal fractures. The **thumb spica splint** is applied for scaphoid fractures and first metacarpal injuries. The **posterior ankle splint** is used for ankle fractures and Achilles tendon injuries. The **bulky Jones dressing** provides knee immobilization with maximum swelling control.

### Application Principles

Splint material is typically **8-12 layers** of plaster or pre-fabricated fiberglass. Adequate padding (minimum 4 layers of cotton) prevents pressure injuries. The splint should encompass **two-thirds of the circumference** of the extremity and is secured with elastic bandages, avoiding circumferential tape. Joints are maintained in a **functional position** unless specific reduction demands otherwise.

![Illustration showing the proper application of a sugar-tong forearm splint from the metacarpal heads around the elbow to the dorsal hand](sugar-tong-splint-application.jpg)

## Traction

### Principles of Skeletal Traction

**Skeletal traction** uses a pin or wire through bone to apply longitudinal force along the limb axis, restoring and maintaining limb length by counteracting muscular deforming forces. It is primarily used as a temporizing measure prior to definitive fixation. Weight applied is typically **10% of body weight** for femoral traction as a starting point.

### Common Traction Configurations

The **distal femoral traction pin** is placed from medial to lateral, 2 cm proximal to the superior pole of the patella and posterior to the mid-axis of the femur. The **proximal tibial traction pin** is placed from lateral to medial, 2 cm posterior to the tibial tubercle, with risk to the **peroneal nerve** on the lateral side. The **calcaneal traction pin** is used for tibial shaft fractures and placed from medial to lateral to protect the neurovascular bundle. **Gardner-Wells tongs** provide cervical spine traction for facet dislocations, with pins placed 1 cm above the pinna in line with the external auditory meatus.

### Skin Traction

**Buck traction** applies longitudinal traction to the lower extremity via adhesive strips or boot. It is limited to 5 pounds (2.3 kg) maximum to avoid skin breakdown and is used for temporary comfort in hip fractures awaiting surgery. It is contraindicated in patients with fragile skin, peripheral vascular disease, or dermatologic conditions.

### Monitoring Patients in Traction

**Neurovascular checks** are performed every 2-4 hours, assessing sensation, motor function, pulses, and capillary refill. Pin sites are inspected daily for signs of infection (erythema, drainage, loosening). Proper weight alignment must be ensured so that weights hang freely and do not rest on the floor or bed frame. Follow-up radiographs are obtained within 24 hours and after any weight adjustment.

![Clinical photograph demonstrating the setup of distal femoral skeletal traction with a Steinmann pin and balanced suspension](skeletal-traction-setup.jpg)

## Complications

### Cast and Splint Complications

**Compartment syndrome** is the most feared complication; circumferential casts must be bivalved immediately if suspected. **Thermal burns** can occur because plaster generates heat during its exothermic setting reaction, with risk increasing with more layers and hotter water. **Pressure sores** develop over bony prominences from inadequate padding or indentation of wet cast material. **Skin maceration** results from moisture trapped beneath the cast, and patients should be instructed to keep casts dry. **Joint stiffness** from prolonged immobilization can cause contracture, making early mobilization of adjacent joints essential.

### Traction Complications

**Pin site infection** ranges from superficial cellulitis to osteomyelitis and is managed with local care and antibiotics. **Nerve injury** results from improper pin placement, risking the peroneal nerve at the proximal tibia or the posterior tibial nerve at the calcaneus. **Over-distraction** from excessive traction weight can cause non-union or neurovascular stretch injury. **Deep vein thrombosis** affects immobilized patients and requires thromboprophylaxis.

## Key Clinical Pearls

Always **bivalve a circumferential cast** in the acute setting if there is concern for swelling, as a bivalved cast with spread padding can reduce compartment pressure by up to 65%. Use **plaster for initial fracture casts** requiring precise molding, then consider conversion to fiberglass once swelling has resolved. Skeletal traction pins in the proximal tibia should be inserted from **lateral to medial** to minimize risk to the peroneal nerve, while calcaneal pins go **medial to lateral** to protect the neurovascular bundle. Instruct patients on the warning signs of **compartment syndrome** -- pain out of proportion, pain with passive stretch, progressive numbness -- and to seek emergency evaluation immediately.

## References

1. Halanski M, Noonan KJ. Cast and splint immobilization: complications. *Journal of the American Academy of Orthopaedic Surgeons*. 2008;16(1):30-40.
2. Bong MR, Koval KJ, Egol KA. The history of intramedullary nailing and skeletal traction. *Bulletin of the NYU Hospital for Joint Diseases*. 2006;64(3-4):94-97.
3. Petrisor BA, Ekrol I, Court-Brown C. The epidemiology of casting and splinting. *Injury*. 2006;37(3):263-268.
4. Boyd AS, Benjamin HJ, Asplund C. Splints and casts: indications and methods. *American Family Physician*. 2009;80(5):491-499.