Short Arm Splinting


Background

Short arm splinting is most commonly used for initial support of the injured extremity (whether surgery is planned or not) and for postoperative immobilization of internally fixed fractures. There are several different types of short arm splints. Each lends itself to a specific subset of orthopedic injuries and issues.

Indications

Several indications exist for short arm splinting. This technique can be used to immobilize joints of the hand and wrist or to protect bony and soft tissues in the forearm.

Short arm splints are often used as a means of temporary or preoperative support for a variety of injuries. Bony, ligamentous, or severe soft-tissue injuries to the hand located at the base of the fingers (proximal phalanx) or above (proximal) are adequately immobilized by short arm splints.

Any injuries to the fourth or fifth proximal phalanges, the metacarpals, [1the ulnar side of the wrist, or the distal ulna are amenable to an ulnar gutter splint, a specific type of short arm splint.

Injuries to the second and third proximal phalanges, the metacarpals, or the distal radius may be held with a radial gutter splint. [2 Although distal radius fractures are commonly immobilized in sugar-tong splints, Bong et al showed that radial gutter splints were equally efficacious in maintaining the initial reduction and were better tolerated by patients. [3]

Thumb spica splinting can be used to provide temporary stabilization of scaphoid fractures and a variety of bony and ligamentous injuries to the thumb and first metacarpal. It may be used for postoperative stabilization after repair of the ulnar collateral ligament of the thumb. [45]

Volar and dorsal slab splints (anterior-posterior splints) covering the palmar/dorsal aspect of the metacarpals, the wrist, and the distal forearm are useful for protecting soft-tissue injuries, some carpal bone fractures (excluding scaphoid), and childhood buckle fractures.

Although short arm splints are less frequently used for definitive treatment, there is some support in the literature for long-term use. Short arm support with a removable prefabricated splint has been shown to be as effective as casting in the treatment of pediatric buckle and minimally displaced distal radius fractures while resulting in less complications and higher patient satisfaction. [678Short arm splinting has even been suggested for use in minimally displaced adult distal radius fractures. [9Adult ulna fractures that are minimally displaced may be treated in a functional brace. Prefabricated wrist splints are often used in the treatment of carpal tunnel syndrome.

For fractures and ligamentous injuries that are accompanied by open wounds or burns, a splint may be used instead of a cast for definitive treatment. The splint allows easier access to the superficial tissues while still treating the bony or ligamentous injury. Removable wrist splints may also be used as the definitive treatment for mild carpal tunnel syndrome and sprains of the wrist.

Short arm splints are also placed after the completion of definitive surgical fixation in order to protect the surgical site. [1011For the most part, these postoperative indications are dependent on the surgeon’s preference. They tend to mimic the indications for preoperative and temporary fixation (eg, a thumb spica splint after thumb/first metacarpal surgery or a volar slab splint after carpal tunnel release). These postoperative splints are used to protect the incision, as well as to temporarily immobilize the recently repaired anatomy.

In a randomized clinical study of 30 patients who underwent surgical repair of skier's thumb, the use of a modified spica splint that allowed immediate postoperative motion led to enhanced patient function and a shorter time to functional recovery as compared with the use of a standard spica splint. [12]

Contraindications

Contraindications for short arm splinting are relatively sparse. On occasion, the soft-tissue injuries accompanying fractures may be so severe as to make splinting for anything longer than a few hours impractical. These severe soft-tissue injuries would normally necessitate prompt operative intervention.

After some procedures, particularly those involving the microvasculature, splints may interfere with the required monitoring, but a splint can usually be modified so as to allow for this. If frequent wound care is required, a removable splint is generally used.

In cases of decreased ability to feel the skin (neuropathy), both splinting and casting can lead to skin breakdown without the patient realizing. Skin checks are recommended to minimize the chance of such ulceration. Finally, long-term splinting across joints can lead to stiffness and sometimes permanent loss of joint motion, especially in the joints of the hand and fingers.

Technical Considerations

Best practices

Short arm splints should not be used when prevention of pronation and supination is necessary. In this case, a sugar-tong splint, a long arm splint, or a long arm cast should be considered.

The decision to apply a splint rather than a cast requires several considerations. Although casts provide more support by virtue of their circumferential nature, they can be more difficult to apply. In addition, applying rigid circumferential material in an acute injury setting does not allow for the variations in swelling that may take place.

Thus, casting in the face of an acute injury runs the risk of neurovascular compromise, skin pressure ulceration, and compartment syndrome. Although these conditions are still possible in a splint, especially a poorly applied splint, they are more likely to occur with casting.

In the majority of conditions, splinting should not be a long-term treatment. In the setting of acute injuries, splints are often applied as a means of temporary stabilization either preoperatively or until a cast can be applied. In this case, follow-up should be arranged promptly (usually in less than 2 weeks) both to monitor the splint and to arrange for definitive care.

Earlier follow-up or even constant monitoring on an inpatient basis can be considered for those patients with severe injuries necessitating prompt operative intervention or those patients in whom pain and neurovascular status are difficult to monitor because of preexisting neurologic conditions or inability to communicate.

Although there is some variability in the literature on this issue, full-time splint wear appears to lead to more symptomatic and functional improvement than nighttime wear alone. [13]

Procedural planning

The first steps in applying a short arm splint involve preparing the patient. Before any splint application, especially those involving a reduction of a fracture or a joint dislocation, the neurovascular status of the injured extremity must be determined and documented. The arm should be clean and dry, and any open wounds should be irrigated and addressed.

Complication prevention

Most complications of splinting can be avoided by proper splint application. Extremes of flexion or extension are avoided to prevent discomfort and muscle or tendon damage. Proper padding of the splint at all bony prominences can help prevent pain, irritation, thermal burns, and pressure sores. The neurovascular status of the arm is monitored during and after the splinting procedure.

Proper splint application for fractures involves a three-point mold technique. Attention to this detail can prevent loss of reduction in some less stable fractures. Special consideration should be made for any patient in whom it will be difficult to monitor discomfort and neurovascular status after splinting. If a patient is unable to communicate the pain that is felt, careful splint application and prompt follow-up are important to avoid complications.

Prolonged splint immobilization of joints can lead to stiffness and permanent loss of motion, and this issue should be considered in arranging follow-up. Pressure injuries and skin breakdown are common complications of splint usage. These can usually be avoided by proper splint application and patient follow-up. Adequate padding of the splint can dramatically decrease the risk. Any splint that gets dirty or wet should be changed; these conditions increase the risk of skin breakdown and infection.

The most serious complication of splints is the potential for compartment syndrome. This condition is less common in the upper extremity than in the lower extremity, and its incidence is lower when a splint is used rather than a circumferential cast. However, if a splint is applied incorrectly, compartment syndrome can still occur, especially after severe trauma to the forearm.

Several mistakes in splint application can increase the chances of compartment syndrome, including the following:

  • Circumferential application of nonstretching cotton gauze over an open wound (blood can cause the cotton to harden and restrict swelling)
  • Failure to place the arm in the position of function
  • Excessively tight wrapping over the splint

The most important aspect of splint application for avoiding compartment syndrome is careful monitoring of the patient. Any changes in neurovascular status should be considered an urgent indication for splint removal and reexamination. In addition, a splinted arm, especially after reduction of a displaced fracture, should be more comfortable than before. Therefore, increasing pain in a splinted extremity should also be cause for concern.


Patient Education and Consent

Patients should be instructed on proper splint care. The splint should be kept clean and dry. Plaster will break down if submerged in water, and once this occurs, the splint will no longer provide stability. Fiberglass will not weaken, but the cotton padding inside will become wet and remain so against the skin. This can contribute to skin breakdown.

On occasion, a splint may be applied in a manner that leads to undue pressure or abrasion at certain areas of the skin. Patients should be instructed not to modify the splint on their own but to return to their healthcare provider promptly so that the splint can either be modified or changed.

Most important, patients should be instructed on the symptoms of possible compartment syndrome. Pain that seems to be out of proportion to the injury or that increases after splinting is the primary early symptom of impending compartment syndrome. Changes in neurovascular status (eg, dusky or pale fingertips, numbness, or tingling) are late signs of compartment syndrome. By the time these symptoms manifest, permanent damage may already have occurred .

Equipment

Certain supplies are needed to apply a short arm splint of any kind. Cast padding, splinting materials (plaster or fiberglass), and water are all that is truly needed to apply a proper splint. For some fractures, especially distal radius fractures, the use of finger traps and weights hung from the arm may facilitate fracture reduction and splint application through ligamentotaxis (see the image below).

Short arm splinting. Use of finger traps and weighShort arm splinting. Use of finger traps and weights in fracture reduction and splinting.

The material used to construct the splint can be either plaster or fiberglass. Plaster is cheaper and generally considered easier to apply because of its superior flexibility in comparison with fiberglass. [14Both materials generate heat during the process of setting and carry a risk of thermal burn during application.

Fiberglass is more radiolucent and lighter than plaster, and these qualities make it desirable to both the patient and physician. However, the increased cost and difficulty of application may offset these benefits. For most situations in the upper extremity (usually temporary fixation), a well-padded plaster splint is sufficient.

Patient Preparation

Anesthesia

The type of anesthesia required for splint application depends on the injury and patient’s condition. In most acute injuries to the forearm and hand, a splint can be applied with only local or regional anesthesia. On rare occasions, moderate sedation may be required for proper application of the splint without undue patient discomfort.

Positioning

The patient may be either supine or in a seated position. The arm should be carefully placed in the position of function, with the wrist slightly extended, the metacarpophalangeal (MCP) joints flexed toward 90º, and the arm in neutral supination (see the image below).

Short arm splinting. Position of function for arm.Short arm splinting. Position of function for arm. Elbow is flexed near 90 degrees but not past. Arm is in neutral rotation. Wrist is slightly extended, with metacarpophalangeal joints flexed.

The wrist should be splinted in neutral position, rather than the extension present in many prefabricated splints. [15]

Monitoring & Follow-up

Once the splint is applied and fully hardened, an elastic wrap is often used to hold the splint and to protect it. It is, once again, important to observe and document the neurovascular status of the involved arm. Any changes in the neurovascular status as compared with the presplinting examination should be considered the result of splint application (or fracture reduction). Efforts should be made to reverse that change, including removal of the splint.

The patient should be asked about his or her comfort level in the splint. Any discomfort felt immediately after splinting could indicate improper splint application and increase the risk of complications. Timely follow-up is encouraged to avoid excessive time in the splint and to receive prompt care for the injury. For the majority of conditions, follow-up should be done within 2 weeks of splinting.


General Steps in Splinting

Once the steps of preparation are complete, the splint may be applied. Each type of short arm splint is applied somewhat differently, but there are basic steps that are common to all of them.

A stockinette should be placed over any part of the arm to which the splint will be applied. This stockinette should be cut long on each end so that it extends past the splinted area (see the image below).

Short arm splinting. Stockinette applied to arm. Short arm splinting. Stockinette applied to arm.

After the stockinette is placed, several layers of cotton cast padding are applied, with close attention paid to areas of bony prominence, such as the ulnar head and knuckles (see the image below). For simple splints, the layers of padding and splint material may be applied together. Commercial preparations consisting of fiberglass surrounded by padding material are also available.

Short arm splinting. Cotton cast padding is applieShort arm splinting. Cotton cast padding is applied over stockinette, with special care taken to pad any bony prominences well.

In the case of splint application to maintain fracture reduction, a three-point mold technique is used. This involves applying pressure at the fracture site on one side while simultaneously applying pressure above (proximally) and below (distally) on the opposite side.

The mold technique is performed while the splint is hardening. Fingertraps should be used during the mold to avoid focal points of pressure on the skin. Fractures that have been reduced have a tendency to fall back into their original angulation, and application of a splint in this manner can help maintain the reduction. The pressure at these locations should be maintained until the splinting material is fully hardened.

Ulnar Gutter Splint

The ulnar gutter splint is applied to the ulnar aspect of the arm. Its proximal extent depends somewhat on the location of injury but should extend at least above (proximal to) the ulnar midshaft. Distally, the splint extends over the metacarpophalangeal (MCP) joints at least to the proximal interphalangeal (PIP) joints and possibly past the distal interphalangeal (DIP) joints, depending on the location of injury.

This splint covers the fourth and fifth digits both volarly and dorsally. For injuries to the fourth digit or metacarpal, the third digit should be included as well. Again, the arm should be placed in its position of function prior to splinting. Cast padding should be placed between the involved digits to avoid skin maceration. [16(See the image below.)

Short arm splinting. Ulnar gutter splint with plasShort arm splinting. Ulnar gutter splint with plaster applied over cast padding and with elastic wrap applied over plaster.

Radial Gutter Splint

The radial gutter splint is similar in function to the ulnar gutter splint, except that it is used for injuries to the second or third rays. It is applied in much the same fashion as the ulnar gutter splint, but on the radial aspect of the arm. The thumb is left free, and the second and third digits are splinted as with an ulnar gutter splint. (See the image below.)

Short arm splinting. Radial gutter splint. Short arm splinting. Radial gutter splint.

Thumb Spica Splint

The thumb spica splint is applied to the radial aspect of the distal forearm. It extends proximally to the radial midshaft or higher. Distally, it encircles the thumb and extends to the interphalangeal (IP) joint of the thumb or past it, as necessary (see the image below). The thumb may be slightly flexed at the joints. [1718]

Short arm splinting. Thumb spica splint made with Short arm splinting. Thumb spica splint made with prefabricated fiberglass splinting material.

Volar/Dorsal Slab Splint

Volar and dorsal slab splints are applied to the volar (anterior) and dorsal (posterior) aspects of the arm, respectively (see the images below). Their proximal and distal extent depends on the location of injury. A typical use for a volar splint after carpal tunnel surgery would have the splint extend proximally to the midarm and distally to the midpalm.

Short arm splinting. Volar (left) and dorsal (righShort arm splinting. Volar (left) and dorsal (right) slab splints made with prefabricated fiberglass splinting material.
Short arm splinting. Dorsal slab splint with elastShort arm splinting. Dorsal slab splint with elastic wrap.

Sugar-Tong Splint

The sugar-tong splint is a long slab of either plaster or fiberglass folded into the shape of a U (see the image below). The splint goes down the dorsal aspect of the arm, loops around the distal humerus region with the elbow bent at approximately 90º, and goes back up the volar aspect of the arm. This splint is designed to limit pronation and supination.

Short arm splinting. Sugar-tong splint. Short arm splinting. Sugar-tong splint.



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