A splint is a temporary orthopedic device used to immobilize an injured extremity, providing support and protection. Unlike a cast, which wraps fully around the limb, a splint is non-circumferential and adjustable, making it useful for acute injuries where swelling is expected. The long arm splint is a specific immobilizer designed to stabilize the bones and joints of the upper limb. Its application is a crucial first step in managing certain fractures and dislocations before definitive treatment, such as a full cast or surgery.
Defining the Device and Its Reach
The long arm splint restricts movement across two major joint complexes: the elbow and the wrist. It generally extends from the proximal third of the upper arm, crossing the elbow joint, and continues down to the wrist area. Its primary function is to prevent the bending and straightening of the elbow (flexion and extension), and the rotation of the forearm (supination and pronation). This comprehensive immobilization prevents disruptive movement at the injury site.
The device is constructed using layers of soft padding, such as cotton web roll, applied directly to the skin, followed by rigid splinting material. These rigid materials are typically strips of plaster or fiberglass that are moistened and molded to the contour of the arm. Because the splint does not fully encircle the limb, it is secured with an elastic bandage wrapped over the top, allowing for expansion if the injured limb swells. This open design differentiates the splint from a cast, which is a fully rigid, circumferential shell.
Conditions Requiring a Long Arm Splint
The long arm splint is indicated for injuries requiring stabilization of both the elbow and the structures distal to it. Common bony injuries treated include fractures of the distal humerus (the lower end of the upper arm bone) and olecranon fractures (the bone at the tip of the elbow). It is also used for complex elbow fracture-dislocations after the joint has been realigned.
The splint provides stability for specific forearm injuries, such as a Monteggia fracture, which combines a proximal ulna fracture and a radial head dislocation. Unstable forearm fractures involving both the radius and ulna often require the added elbow immobilization provided by the long arm splint. This device is an initial, temporary measure designed to hold the limb securely until swelling subsides and a transition to a cast or other permanent fixation can occur.
Application and Initial Instructions
The application process begins with placing a stockinette and soft padding over the entire area the splint will cover, ensuring extra material is layered over bony prominences like the elbow’s olecranon. The splinting material, which may be a combination of a posterior strip and a “sugar tong” strip, is prepared by immersion in water to activate the material. This material is then precisely molded to the patient’s arm, often with the elbow positioned at a 90-degree angle and the forearm in a neutral, thumb-up position for optimal stability.
The splint is held firmly in place with an elastic wrap, which must be taut enough to maintain position but not constrict the limb. Patients receive specific instructions to ensure the splint remains effective and safe. They must keep the splint completely dry, as moisture can compromise the padding, leading to skin irritation or loss of rigidity. The patient must also keep the injured arm elevated, ideally above the level of the heart, particularly during the first two to three days, to minimize swelling.
Recognizing Complications
Swelling from the injury can increase and lead to serious complications if not recognized quickly. The most concerning signs indicate neurovascular compromise, meaning blood flow or nerve function is being affected. Patients should immediately seek medical attention if they experience severe, unrelenting pain that is not eased by elevation or pain medication. This pain may signal excessive pressure developing within the arm, which is a symptom of compartment syndrome.
Other warning signs include new or worsening numbness and tingling in the hand or fingers, which indicates pressure on the nerves. A change in the color of the fingers, such as coldness or a blue tint, suggests impaired circulation. If the splint feels suddenly much tighter or if the patient cannot move their fingers as instructed, these also represent urgent issues. Monitoring these symptoms is the patient’s primary responsibility to prevent long-term damage.