How Do You Wrap a Thumb Spica Splint?

A thumb spica splint is used to minimize movement and support an injured thumb.

A splint is a rigid or flexible device that maintains in position a displaced or movable part and protects it from any further damage.

Splints are usually applied to reduce movement and provide support and comfort by stabilizing an injury. 

Splints are primarily used during nonemergency injuries to the bones or ligaments until they can be evaluated by a consultant such as an orthopedic surgeon. They are also used to temporarily immobilize an extremity before the surgery (e.g., for an open fracture) or enable healing.

Unlike casts, splints are preferred in an emergency setting, where injuries are often acute and swelling may continuously increase. All patients with injuries that are splinted should be referred for evaluation by a consultant within two to seven days.

Thumb spica splints are a type of orthopedic splint applied to minimize movement and provide support and comfort by stabilizing an injury of the thumb. This kind of splint usually allows the other fingers to move freely. 

Immobilizing the joint reduces pain and helps the injury heal faster. Studies report the combination of corticosteroid injection with thumb spica cast may yield better results than injection alone in inflammatory conditions.

A thumb spica splint can be used for various injuries, including the following:

• Injuries and fractures of the anatomical snuffbox (area over the thumb base) and thumb
• Ligament injuries and inflammation
• Inflammation of the tendon 
• Gamekeeper’s or skier’s thumb: It is an injury and inflammation of the ligament in the space between the thumb and index finger. Patients present with pain, swelling, and inability to grasp any object between the index finger and thumb.
• Tenosynovitis: Inflammation of the tendon sheath (where the muscle connects the bone) that may occur in the hand, wrist, or foot. It is caused by trauma, joint overuse, playing racquet sports (e.g., tennis, golf, etc.) regularly, or infection. Patients present with pain, swelling, and difficulty moving the joint. A thumb injection with corticosteroid along with thumb spica splinting is usually effective in 80% of patients with tenosynovitis.

There are no absolute contraindications for thumb spica splint. Relative contraindications involve injuries that require immediate evaluation or an intervention by a consultant (an orthopedic surgeon, a hand surgeon or a plastic surgeon) such as the following:

• Complicated fractures
• Open fractures
• Injuries with associated neurovascular compromise

There are various types of thumb splints made of various materials and have different techniques of application. Thumb spica splints are generally applied by a healthcare professional.

Anesthesia

Thumb spica splinting is usually tolerated without the use of anesthesia. In case of significant pain during joint manipulation or reduction of fracture, anesthesia and painkillers would be required.

Splinting of the thumb

The injured limb is completely exposed. A stockinette is applied to the thumb, extending beyond the wrist. Soft padding is applied over the stockinette. The padding should extend 2-3 cm beyond the overlying plaster on both ends. 

Plaster of Paris (POP) is applied over the padding. A bandage wrap is applied over the wet plaster. The thumb and wrist remain immobile until the splint is dry. Patients may feel some warmth released from the plaster as it dries.

In case of a simple sprain, the doctor may advise a simple brace with Velcro clips or a bandage wrap to be worn for two to six weeks to immobilize the joint.

Aftercare

Patients are advised to rest, elevate, and ice the injured limb. If they experience weakness, numbness, color change (pale or bluish), increasing pressure or pain, or spreading redness, they are advised to remove the splint and visit the emergency department right away. 

The splint must be kept clean and dry. Patients may be tempted to use sticks, pens, or hangers to scratch an itch inside the splint. Sticking objects into the splint to scratch an itch can wrinkle the padding and lead to pressure injuries or cause cuts in the skin, leading to infection. The splint is usually rechecked in 48 hours by the doctor.

Thermal burns may occur due to the warmth as the plaster dries

• Pressure sores
• Contact dermatitis
• Neurovascular compromise (damage to nerves and blood vessels)
• Decreased range of motion from immobilization
• Because of these complications, splint aftercare often requires physical therapy.