Chapter XIX.2. Splinting
Maveric K. Abella
Rachel A. Coel, MD, PhD
Christopher T. Lynch, MD
June 2023

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The editors and current author would like to thank and acknowledge the significant contribution of the previous author of this chapter from the 2002 first edition, Erick M. Itoman. This current third edition chapter is a revision and update of the original authorís work.


A 7-year-old female presents to the clinic with a chief complaint of left wrist pain. She was rollerblading with several friends and was accidentally pushed from behind. She fell forward with outstretched and pronated arms. She denies hitting her head, loss of consciousness, vomiting, or abdominal pain.

Exam: VS T 37.0, P 105, R 20, BP 117/75. She is comfortable, alert, and appears to be in mild discomfort. Mild abrasions are noted on her left knee and palmar surfaces of both hands. No obvious puncture wounds are present. She has mild discomfort upon palpation of her left knee, but she is able walk, stand, and jump without difficulty or discomfort. Her right wrist exam is normal. Tenderness is elicited upon palpation of her left distal radius. There is mild left wrist swelling noted, but no angular deformity is present. The remainder of her exam is unremarkable.

Radiographs reveal a non-displaced distal radius fracture of the left wrist without angulation. She is placed in a volar splint and sling, and her mother is given instructions to follow-up with an orthopedic surgeon.


Temporary splints are used to briefly immobilize fractures, subluxations, sprains, or soft tissue injuries. Other indications for splinting include acute arthritis, severe contusions/abrasions, skin lacerations, burns across joints, tendon lacerations, tenosynovitis, animal bites, deep space infections, joint infections, and puncture wounds (1). The goal of splinting is immobilization to minimize pain and prevent further damage to bones, joints, nerves, vessels, muscle, and skin. (2). Regardless of the injury mechanism, tissue damage results in inflammation. Immobilization of the injured limb minimizes irritation and reduces edema (2). Immobilization also reduces joint pain and inflammation from a variety of other disease states including tenosynovitis, hemarthrosis, or acute arthritis. Abrasions and lacerations that cross joints can be stretched open if the extremity is not immobilized. Immobilization of fractures reduces the degree of pain, risk of further displacement, minimizes hemorrhage, soft tissue damage, and risk of neurovascular injury.

A splint can be intended for temporary or long-term use. The most common indications for temporary splints are acute orthopedic injuries such as fractures. Most fractures have associated swelling and applying a rigid cylinder cast over this swelling poses two risks: 1) The swelling could increase resulting in circulatory compromise. 2) The swelling will eventually decrease resulting in a cast with a loose fit. While most patients might expect an immediate cast, explaining this helps them to understand why a splint is best applied immediately with a subsequent evaluation for casting in 1 to 3 days.

The two main categories of temporary splints are plaster and fiberglass. However, other materials can be used such as cardboard, aluminum, and other semi-rigid or malleable materials. Plaster splints are made from gauze material impregnated with plaster of Paris, which is made from gypsum. Gypsum loses water when heated and is reduced to a powder. When water is added, the gypsum powder hardens as the calcium sulfate dihydrate molecules recrystallize (1). The reaction is exothermic and can possibly burn the patient if performed incorrectly, but typically the material simply feels warm. Depending on the temperature of the water the plaster may take anywhere from 2 to 8 minutes to set, with hot water allowing for a quick setting time. Although the plaster hardens after the first ten minutes it takes about a day to reach maximum strength. Plaster has the distinct advantage of customization and molding to the individual's injury site, but it can be difficult to work, messy, and heavy (1). An upper extremity injury may require 8 to 10 layers of plaster and the lower extremity may take 10 to 20 layers (3). Despite the large amount of material used and the time-consuming nature of the plaster process, plaster splinting less expensive (1). Once the plaster has set, water must be avoided. Excessive water will cause the crystallization to become unstable, making the splint soggy, causing it to break down.

The newer fiberglass splint materials come prepackaged with padding. The prepackaging reduces the steps needed to prepare the limb prior to splinting but increases the cost and limits the customizable splinting options. The padding also absorbs water and sweat well, minimizing the accumulation of moisture (1). Fiberglass has several other advantages over plaster. It is lighter, stronger, has a quicker set time, and is not as messy as plaster. The fiberglass hardens in minutes and cures in approximately 10 to 20 minutes (1,3). It is easily affixed to the limb with an elastic bandage; however, due to its prefabricated nature, fiberglass does not mold to the individual's anatomy as well as plaster. Wrinkling may occur where the splint is bent to fit the limb (3). Even small wrinkles may be a potential pressure point location of irritation, causing pain, skin injury, and pressure sores.

Regardless of the material utilized, the procedure for splinting should always start with a general inspection of the limb. Abrasions, cuts, and lesions need to be cleaned and dressed. Next the limb should be rechecked for signs of deformity, compartment syndrome, or neurovascular compromise. The splint width should be approximately half as wide as the circumference of the extremity. The following steps in the procedure will vary based on the type of splint material used.

For either plaster or fiberglass splints, the limb should be prepared for the splint similarly. The plaster strips or fiberglass prefabricated material should be measured and cut to a length to properly support the limb. As the injured limb will be painful to move, the posterior surface of the affected limb or the uninjured limb may be used as a measuring guide. The splint material should be cut to a length slightly longer than needed. This will allow the splint to be folded upon itself to provide a smooth edge and allows for a margin of error. A longer length will also allow for contraction of the plaster as it crystallizes (3). An initial layer of stockinette can be rolled over the limb and cut to a length longer than is needed. This layer can protect the skin from excess moisture and from irritation from splinting materials. The stockinette should look as if a long sock with an open hole has been placed over the extremity. Take time to smooth out the stockinette to prevent pressure spots and kinks at flexion creases. Alternatively, you may make a linear cut in the stockinette material along the flexion crease to lay it flat and prevent wrinkling. The stockinette is positioned with extra material both proximal and distal to the area being splinted. This excess material will allow the stockinette to be later folded over the hard splint ends to protect the patientís exposed skin from abrasive edges. Cast padding rolls should be applied over the extremity in layers in a distal to proximal direction. If stockinette has been used, then the cast padding is rolled carefully without wrinkling over the stockinette. Each successive roll of cast padding around the extremity should cover the previous roll by approximately 50% to 60% (3). This overlap will ensure a double layer of padding over the area to be splinted. Extra padding should be placed over bony prominences, such as the olecranon, patella, ulnar styloid, or heel. This extra cushion will minimize pressure and discomfort. Make sure that the excess stockinette distal and proximal to the area being splinted is not covered with cast padding.

The plaster should now be immersed in water. Plaster sets more quickly with warmer water When casting children the water should be on the cooler side. The plaster will heat up as it hardens, and this may scare or burn a child. Place the wet plaster on an open towel. Remove excess water, smooth the plaster, then apply the strip to the extremity. Adjust and position the plaster accordingly while smoothing to the contour to the patient's anatomy. While the plaster is still soft, fold the proximal and distal ends of the plaster back over itself by approximately one-half inch to provide a smooth edge. If a stockinette is used, fold it back over itself, the cast padding, and the plaster before applying the final elastic bandage layer. A smooth padded edge should be present at both ends of the splint. An optional cast padding layer can be applied over the splint to prevent the soggy plaster from incorporating into the overlying elastic wrap applied thereafter. Roll the elastic bandage over the outside of the extremity, usually in a distal to proximal fashion, securing the plaster to the extremity. Keep the limb in the desired position until the plaster thoroughly hardens.

Water soluble fiberglass splints involve fewer steps. Fiberglass splint materials come encased in cast padding material rather than bare sheets of fiberglass. Once the limb has been inspected and the proper splint width and length are selected, cut the length needed and wet the fiberglass splint with water. The fiberglass will harden more quickly with warmer or increased volume of water. Place the splint on a dry towel and remove the excess water from the fiberglass splint by rolling it in a dry towel and applying pressure. This can be repeated until the outside of the fiberglass splint material feels fairly dry. The padding material should be stretched over the end of the fiberglass or the inner layer of fiberglass should be cut down a quarter inch (0.5 cm) or the padding can be stretch to cover the end of the fiberglass to prevent the sharp fiberglass ends from poking the patient. Because the fiberglass is prepackaged with a layer of padding, some providers believe it has enough padding to be directly applied. However, utilizing the stockinette and additional cast padding provides more comfort, and reduces the potential for skin injury, or pressure sores from any unseen wrinkles in the fiberglass material (3). Once the fiberglass is placed over the extremity it should be molded to the necessary shape and custom fit of the individual patient. If a stockinette is used, fold it back over itself, the cast padding, and the fiberglass splint before applying the final elastic bandage layer. An elastic bandage should then be applied to secure the fiberglass splint in place (3). Like the padding, the elastic bandage should be rolled on the limb with a 50% to 60% overlap of each layer. Light tension on the elastic wrap should be applied to hold the splint in place, but the elastic bandage should not be applied too tightly, since this increases the risk of swelling, pain, and/or compartment syndrome.

The final step in any splinting procedure should be to check the extremity for signs of neurovascular compromise. Capillary refill should be brisk, and sensation to light touch and pin prick should be intact. The patient should also be able to move the distal anatomy with minimal discomfort. The patient should be comfortable and relaxed in the splint. There should be no rough or sharp edges on either end of the splint. Depending on the type of splint, other accessories may be beneficial for the treatment of the patient. These materials may include a sling for upper extremity splinting and a cast shoe or crutches for a lower extremity splint.

The patient and parents need to be advised of the complications of splinting. In fracture cases where swelling is prominent, the limb may expand in girth. The splint is a partial covering, not a rigid cylinder, and the elastic wrap permits some expansion for extremity swelling, preventing harmful circumferential pressure by the splint. Nevertheless, if the elastic bandage is applied too tightly, neurovascular injury may occur. Signs such as tingling, numbness, increasing pain, or paresis may indicate the development of compartment syndrome. The patient and family should be counseled to return to the emergency department immediately if any of these signs or symptoms develop. Preventative measures should be taken such as limb elevation and periodic monitoring of the distal anatomy (1). Finally, the patient should be instructed to keep the splint clean and dry. Moisture will soften the skin and the splint, promoting itching, infection, pressure sores, and splint breakdown. Any discomfort on the skin could suggest pressure sores. The patient should be given instructions for follow-up with a contact number in case of complications.

The following examples demonstrate some of the most common extremity splints . In all cases, the splint should be constructed with techniques detailed above and specific shape as described below. In each instance stockinette and cast padding is applied to the extremity, the splint material is applied as noted below, and an elastic bandage is applied over the extremity such that the splint material properly molds to the shape of the extremity without undue pressure.

Upper extremity volar forearm/wrist splint (1): Indicated for minor stable fractures near the wrist (e.g., torus/buckle fractures of the distal radius), soft tissue injuries to the hand and wrist, and stable fractures of the carpals and metacarpals. Extend the splint from the metacarpal heads of the palm to the volar surface of the forearm proximal to the elbow. The forearm is placed in the neutral position and the wrist should be slightly extended in a position of comfort. The palmar end of the splint should be rolled so that the hand can rest in a flexed position over the roll. Confirm that there are no pressure points at the thumb or small finger areas.

Upper extremity posterior long arm splint (1): Indicated for elbow and forearm injuries, and/or immobilization of both the elbow and wrist joints. The elbow should be flexed at approximately 90 degrees to a position of comfort, and the forearm should be in neutral position with the thumb up such that the volar side of the forearm is toward the body with slight extension at the wrist. The splint should extend from the metacarpophalangeal joint to the upper arm just distal to the axilla. The splint will be applied on the ulnar surface of the wrist and forearm and extend to the posterior surface of the upper arm. Be aware that wrinkling can occur near the flexed splint area at the elbow joint.

Upper extremity ulnar gutter splint (1). Indicated for fractures of the 4th and 5th fingers or metacarpals. The splint material is folded on its long axis such that the ulnar side of the fingers, hand, and forearm fit into the long gutter formed by the splint. This should extend from the distal 5th finger or metacarpal to the proximal forearm just distal to the elbow. Flex the metacarpophalangeal joints to approximately 70 degrees for a position of healing.

Upper extremity forearm sugar tong splint (1,4): Indicated for distal radius, wrist, and forearm fractures. This prevents supination pronation of the forearm and flexion/extension of the wrist, and blunt trauma to the fracture site. This type of splint provides superior immobilization compared to the volar forearm and ulnar gutter splints. Extend the splint from the palmar aspect of the metacarpal heads, along the volar forearm, around the elbow, and to the dorsal aspect of the forearm, ending at the dorsal metatarsal heads. The thumb should be unopposed, and the remaining digits should be allowed 90 degrees of flexion. Flex the elbow approximately 90 degrees to allow a position of comfort. The volar surface of the forearm should be facing the body. The palmar end of the splint should also be folded over (i.e., rolled) to allow the fingers to rest in a flexed position over the roll. Watch for wrinkles at the curved area around the elbow joint. This splint is appropriate for most proximal radius fractures but is not the splint of choice for elbow dislocation, olecranon fracture, or humerus fractures. If the elbow is straightened, the end of the splint can fall off the elbow, therefore to prevent this from occurring, the superior aspects of the volar and dorsal segments over the proximal forearm can be slightly angled toward each other to create an angle to prevent the elbow end of the splint from falling off the elbow.

Thumb spica splint (1): Indications include a non-displaced, extraarticular fracture of the thumb, metacarpal, or proximal phalanx. This type of splint can also be utilized for ulnar collateral ligament injuries, and scaphoid pathology such as a fracture or suspected fracture. A thumb spica splint is often placed together with a volar wrist splint for additional control of the wrist. The radial aspect of the hand, wrist, and forearm is placed in the splint so that the splint can form a long U-shape brace down the length of the splint. This is similar to the ulnar gutter splint, but on the radial side. The U-shaped splint will extend proximally from the thumbnail to the mid-forearm. The thumb will be encircled by the distal part of the splint with the tip of the thumb exposed to completely immobilize the thumb. As the splint extends proximally it will open wider to receive the radial surface of the wrist and forearm. The thumb should be slightly abducted, and the wrist should be slightly extended. This prevents the ab-adduction of the thumb.

Lower extremity posterior short leg splint (1): Indicated for high grade ankle sprains and non-displaced fractures of the ankle, foot, and distal fibula. The ankle should be in the neutral anatomic position forming a 90 degree angle. The splint will extend from the posterior lower leg distally covering the plantar side of the metatarsal phalangeal joints. If there is a toe fracture then the splint should extend to the tips of the toes. This splint provides support to the posterior leg, ankle, and foot. The splint should not come too high proximally, avoiding impingement on the popliteal fossa when the leg is flexed. A general guideline to follow is to end the proximal splint approximately 2 finger widths below the knee joint. The patient should be given crutches to discourage weight bearing while splinted.

Ankle stirrup splint (also known as ankle sugar tong splint) (1,4): Indicated for injuries to the ankle, and ankle immobilization against inversion and eversion. Unlike the posterior ankle splint, the ankle stirrup splint provides lateral and medial support. The ankle stirrup splint provides superior immobilization for a fracture within the ankle compared to the posterior ankle splint. The splint is folded into a U-shaped stirrup. The splint will overlay the lateral surface of the calf just distal to the knee, around the plantar midfoot and heel, to the medial surface of the calf just distal to the knee. Ideally, wide splint material should be used so that the bottom of the U-shape will support from the heel and plantar side of the midfoot. The ankle should again be in neutral positioning making a 90 degree ankle. This splint may be used in conjunction with a posterior short leg splint to provide maximal immobilization for painful lower leg injuries, such as high grade ankle sprains, syndesmotic ankle sprains, or significant fractures of the distal tibia and/or fibula.

Posterior long leg splint: Indicated for fractures of the proximal tibia, tibia shaft, distal femur, unstable ankle fractures (such as triplane or maisonneuve fractures), and knee joint sprains. This splint is similar to the posterior short leg splint in the lower leg with the ankle in neutral position but it extends more proximally to include the knee joint in slight flexion and supporting the mid to proximal femur. To provide ample support and immobilization, the splint should run continuously from the plantar surface of the foot, starting at the metatarsal heads and extending to the posterior upper leg. Wider splint size may be required to create an adequate splint and larger width elastic bandages are helpful to cover greater surface area. Avoid wrinkles in the material at the popliteal fossa of the knee and at the area near the heel. Crutches should be provided for patients treated in this non-weight bearing splint, and elevation of the leg is advised. When elevating, patients should be advised to place a pillow under the calf, rather than under the heel, in order to avoid pressure sores at the heel.


Questions

1. What are the common indications for splinting?

2. What is the purpose of splinting?

3. What are the complications involved with splinting, and how should these complications be evaluated by the patient?

4. Should sprains be splinted in a pediatric patient?

5. Briefly compare and contrast plaster and fiberglass splints.

6. When choosing a splint strip size, what is the general rule of thumb?

7. What temperature of water should an inexperienced person use when splinting?

8. What is the first step in splinting?

9. What are some reasons for preferring splinting over casting in the initial day or two after injury?


References

1. Chudnofsky CR, Chudnofsky AS. Chapter 50 - Splinting Techniques. In: Roberts J, Hedges J (eds). Roberts and Hedgesí Clinical Procedures in Emergency Medicine and Acute Care, 7th edition. 2018. W.B. Saunders Company, Philadelphia. pp:1027-1056.

2. Geiderman JM, Katz D. Chapter 42 - General Principles of Orthopedic Injuries. In: Walls RS, Hockberger RS, Gausche-Hill M (eds). Rosenís Emergency Medicine: Concepts and Clinical Practice, 9th Edition. 2018. Elsevier, Philadelphia. pp:445-463.

3. Frey TM, Mittiga MR. Chapter 130 - Splinting of Musculoskeletal Injuries. In: Fleisher G, Ludwig S (eds). Fleisher and Ludwigís Textbook of Pediatric Emergency Medicine, 8th edition. 2021. Lippincott Williams & Wilkins, Philadelphia. pp:1886-1458.

4. Dittmer AJ, Molina D 4th, Jacobs CA, Walker J, Muchow RD. Pediatric Forearm Fractures Are Effectively Immobilized With a Sugar-Tong Splint Following Closed Reduction. J Pediatr Orthop. 2019;39(4):e245-e247. doi: 10.1097/BPO.0000000000001291


Answers to questions

1. Splints are generally used to temporarily immobilize fractures, subluxations, or significant soft tissue injuries.

2. Splints immobilize the extremity, reducing damage to the nerves, vasculature, muscle, and skin. This will minimize edema and pain. Splints also stabilize fractures and prevent further displacement of subluxations. This can be thought of a bridge to casting.

3. If the splint is too tight it will compress the swollen extremity causing decreased sensation, paresthesia, and pain. The patient and family should be educated to check for brisk capillary refill, mobility of distal anatomy, numbness, tingling, burning, and increased pain. Improper immobilization of the joint may cause contractures. Mobility of the distal anatomy should be evaluated. Stiffness of the immobilized joint should be expected. Wrinkles in the splinting material may cause pressure sores and skin breakdown, especially over bony prominences. Early symptoms may include burning or itching sensation allowing for intervention prior to frank ulceration.

4. Conservative treatment involves splinting of the extremity. The general rule of initial management is: when in doubt, splint. Splinting is indicated if there is clinical concern for potential occult fracture. However, many sprains will improve faster with gentle early activity compared to total rest or immobilization.

5. Plaster is inexpensive, and it allows for anatomic molding. However, it is relatively heavy, is messy to work with, and it can take longer to set and cure. Fiberglass is a more expensive, prepackaged, stronger, and light weight splint material that cures quickly without a mess.

6. The width of splinting material should be approximately 50% of the circumference of the extremity.

7. Colder water slows the curing process in both plaster and fiberglass, but room temperature water is preferred. Warm water is best avoided since it will add further heat to the exothermic reaction.

8. Inspection. Wounds must be cleaned and dressed. Neurovascular compromise should be ruled out and documented.

9. Casting forms a rigid cylinder over the extremity. In the first 24 hours following a fracture, swelling within the cylinder may result in vascular compromise and compartment syndrome. Splinting initially, then casting later is associated with fewer complications compared to early casting. Additionally, if the extremity is already swollen and a cast is applied, the fit of the cast will be loose once the swelling resolves. Casts are generally applied by orthopedic practitioners who are not always available. Splints provide an immediate means of immobilizing the extremity, allow the swelling to progress and resolve, and do not require the immediate presence of an orthopedic specialist.


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