Introduction

The technique of volar splinting of the upper extremity can be used to immobilize hard and soft tissue injuries as well as painful non-traumatic conditions. Examples of hard tissue skeletal injuries include distal radius fracture, Colles fractures, and metacarpal and carpal fractures (except the first metacarpal and trapezius). The basic guideline regarding splinting of skeletal lesions is that it must immobilize a joint above and a joint below the lesion. The exceptions to this rule are metaphyseal, such as Colles or Smith fractures which effectively act like injuries within the joint. For more proximal shaft fractures, the principle of volar splinting expands into sugar tong or Muenster-type splinting, extending above the elbow.

Other examples of conditions amenable to volar splinting include acute gouty arthritis, carpal tunnel syndrome, and radial nerve palsy. Splinting is an adjunct to elevation and ice. It improves patient comfort, facilitates recovery, and protects from further injury. Splints may be used for comfort as a temporizing measure for wrist and hand dislocations or fracture subluxations while awaiting definitive care. Splints differ from casts in that the non-circumferential bandage allows for some degree of swelling without undue constriction. Splints can also be easily removed for wound care. Splinting can be the definitive treatment or temporary treatment before casting. Though plaster is the traditional material used, padded fiberglass and preformed plastic splints are common.[1][2][3][4]

Anatomy and Physiology

A fundamental principle when immobilizing a fracture is that the splint must extend at least a joint above and a joint below the fracture. This means that for a metacarpal fracture the splint must extend from the mid-forearm to beyond the MC (metacarpophalangeal) joints. Careful examination and dressing of wounds as well as assessing and documenting neurovascular status should precede splint application.

Indications

The technique of volar splinting of the upper extremity can be used to immobilize hard and soft tissue injuries as well as painful nontraumatic conditions. Examples of hard tissue, skeletal injuries include distal radius fracture, Colles fractures, metacarpal and carpal fractures (except the first metacarpal and trapezius). Examples of soft tissue injuries include large skin lacerations as well as structural soft tissue injuries such as tendon or ligament injuries. A volar splint may also be used to provide symptomatic relief from inflamed and painful, but not injured, joints such as gout, rheumatoid arthritis, or other painful inflammatory conditions.[5][6][7][8]

Contraindications

There are no specific contraindications to volar splinting.

Specific instances such as burns, open or contaminated wounds, or unstable fracture patterns may warrant special consideration. In situations where the limb is tense and edematous, monitoring for compartment syndrome and rapid extension of inflamed or infected soft tissues may make splinting less desirable.

Equipment

• Plaster (no more than 12 sheets) or padded fiberglass
• Stockinette
• Undercast padding
• Bucket of cool water
• Elastic bandage
• Sling

Personnel

Volar splinting can be performed by appropriately trained personnel including physicians, physician assistants, nurses, or technicians. The procedure can be performed by a single operator.

Preparation

Volar splint length depends on the application. For a Colles or other wrist fracture, the splint extends from the second through fifth metacarpal heads (distal palmar crease) to 4 cm to 5 cm distal to the antecubital fossa. For a metacarpal fracture including a Boxer’s fracture, the splint should extend beyond the metacarpophalangeal joint and for a phalanx fracture to beyond the tip of the digits. Plaster takes longer to set and is more pliable than fiberglass.

The hardening of the splint material occurs through an exothermic reaction. The amount of heat released is proportional to the number of layers of cast material and the temperature of the water utilized. Limit the layers of plaster to no more than 12 (usually 8 to 10 layers suffice). Using cool, fresh water allows time to mold the splint and reduces the risk of burn. Apply adequate stockinette and cotton undercast padding to prevent heat penetration. Care is taken to avoid skin contact with plaster or fiberglass. Avoid resting the still wet cast on a pillow or mattress as this will interfere with the dissipation of heat. Extra padding over bony prominences, such as ulnar styloid, will help prevent pressure sores. The elastic wrap is used to hold the splint in place. It should be applied so that swelling is allowed, but the movement is limited. Neurovascular status should be assessed before and after application. A sling is then applied for elevation and protection.

Technique

1. Have all of the materials at hand.
2. Supinate the wrist and hold in 20 degrees of extension.
3. Apply the stockinette and smooth over the extremity with 2 cm extra proximally and distally.
4. Wrap the cast padding, starting at the metacarpal head circumferentially to the antecubital fossa. Avoid wrinkles and gaps in the padding.
5. Thoroughly wet the splint material with cool water and squeeze out the excess.
6. Lay the moist splint along the palmar aspect of the hand, wrist, and forearm to 4 cm proximal to the antecubital fossa.
7. Fold the excess stockinette over the ends of the plaster or fiberglass and wrap under the elastic wrap.
8. Beginning at the metacarpal heads, wrap the elastic bandage with 25% overlap circumferentially around the splint, working proximally, and secure with clips or tape.
9. Mold the splint to the palm and forearm maintaining the 20-degree extension and hold until firm. The elastic bandage should be tight enough to hold the splint in place but allow two fingers to be inserted underneath. 
10. Check the capillary refill. 
11. Elevate the arm with a sling.

Clinical Significance

Volar splinting is a valuable technique for managing traumatic and non-traumatic conditions of the hand and wrist. The splint immobilizes and supports the metacarpals and carpals while allowing room for swelling. The splint can be removed to examine wounds that may accompany the injury.[1][9][1]

Instruct the patient to keep the splint clean and dry. The extremity should be elevated, and an ice pack applied to the splint for 20 minutes every few hours. If the fingers become cold, blue, numb, or painful, seek medical attention. The patient should have close follow up within a few days. The simple removal of the splint allows for wound care in some cases. Inform the patient of the potential complications of splinting and encourage the patient to return should a concern develop.

Enhancing Healthcare Team Outcomes

Volar splinting is often done by therapists, emergency department physicians, orthopedic nurses and surgeons. It is a invaluable technique to stablize injuries of the hand and the digits. At each visit, the splint can be removed and the hand visualized. The key to good outcomes is patient education on keeping the splint clean and knowing when to return to the hospital.