Radial Gutter Splinting 

In general, splints are applied to decrease movement and provide support and comfort by stabilizing an injury. Splints are primarily used to secure nonemergent injuries to the bones and soft tissues of an extremity until it can be evaluated by a consultant such as an orthopedic surgeon. Splints can also be used to assist in primary healing or to temporarily immobilize an extremity prior to surgery (eg, open fracture).^[1] Unlike casts, splints are noncircumferential and often preferred in the emergency department setting, since injuries are often acute and continued swelling can occur. All patients with injuries that are splinted should be referred for evaluation by a consultant in a timely fashion (usually within 2-7 days, depending on the reason for splinting).^[2] See the image below.

For information on surgical treatment of such injuries, see eMedicine articles Carpal Fractures; Metacarpal Fractures; Radius, Distal Fractures; Hand, Metacarpal Fractures and Dislocations; and Hand, Phalangeal Fractures and Dislocations.

A radial gutter splint can be used for various injuries that include the following:

• Soft tissue injuries to the second and third fingers
• Fractures of the second and third metacarpals
• Fractures of the second and third phalanges
• Positioning for rheumatoid arthritis
• Laceration over the joints of the second and third phalanges or metacarpals

• Absolute contraindications - None
• The following injuries require immediate evaluation or intervention by a consultant (eg, orthopedic surgeon, hand surgeon, plastic surgeon) and should not be treated with splinting alone:

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

Splinting is usually tolerated without the use of anesthesia. However, if significant manipulation or reduction of the injury is required during the splinting process, anesthetic techniques may be used. Acceptable techniques include the following:

• Administration of a hematoma block or nerve block (see Anesthesia, Regional, Digital Block or Nerve Block, Radial)
• Procedural sedation with appropriate monitoring and administration by an experienced physician^[3]
• Administration of oral or intravenous pain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs) or opioid analgesic agents

With the administration of any analgesic agent or the initiation of a formal sedation protocol, care should be taken to avoid oversedation. A complete neurovascular examination should be performed after the splint has been applied.

• Stockinette
• Padding (eg, Webril)
• Ready-made fiberglass (eg, Orthoglass) or plaster splinting material (eg, plaster of Paris), 8-10 sheets, 3-4 in wide
• Bandage or wrap (eg, Bias bandage or Ace wrap), 2-3 in wide
• Clean, room-temperature water in a basin
• Trauma shears or a pair of medical scissors without pointed ends
• Chucks pads and bed sheet
• Tape (if using Bias bandage) or bandage clips (if using non-Velcro Ace wrap) (See image below.)Equipment for splint. Image courtesy of Kenneth R. Chuang, MD.

• Place the patient in a comfortable position (eg, seated or reclined).
• Cover the patient with a sheet to avoid splatter from the wet plaster. See the video below.

  Cover patient appropriately. Video courtesy of Kenneth R. Chuang, MD.
• Completely expose the injured limb. Remove clothing on proximal extremity or warn patient that it may need to be removed with scissors after the splint is placed. Remove the patient’s jewelry. In particular, rings can cause constriction and ischemia of the fingers with delayed swelling of the soft tissues. If unable to remove a ring, try using soap as a lubricant or consider a ring cutter. See the video below.

  Remove jewelry and rings to avoid ischemia from swelling. Video courtesy of Kenneth R. Chuang, MD.

• Explain the procedure to the patient, including risks and benefits. Obtain informed consent.
• Position the patient as described above. See Positioning.
• Apply stockinette. Cut longitudinally at the distal end of the stockinette to allow covering for the second and third digits. Then, cut an adequate hole for the thumb, being careful to avoid constriction of the thumb. When measuring the stockinette, cut it longer than the splint. The stockinette should extend 2-3 cm beyond the overlying padding on either end. In turn, the padding should extend 2-3 cm beyond the overlying wet plaster on either end. Together, the stockinette and padding will be pulled over the edges of the wet plaster to create smooth edges. See the video below.

  Stockinette application for radial gutter splint. Video courtesy of Kenneth R. Chuang, MD.
• Begin by placing a piece of padding (eg, Webril) between the second and third digits. This helps prevent maceration of the skin. Then, wrap the padding over the stockinette. Overlap each layer by half the width. Also allow for extra length. The padding should extend 2-3 cm beyond the overlying plaster on both ends. Nails should be left exposed to assess for perfusion. Smooth out creases and avoid wrinkles, unwrapping and rewrapping as necessary. Apply extra padding to the bony prominences of the wrist, the metacarpophalangeal joints (MCP), and the interphalangeal joints. See the video below.

  Cotton padding application for radial gutter splint. Video courtesy of Kenneth R. Chuang, MD.
• Measure the plaster of Paris. For an adult of average size, upper extremity splints, including the radial gutter, should be 8-10 layers thick. Use plaster that is 3-4 in wide. After counting the layers, measure the plaster from the second distal interphalangeal joint to the proximal third of the forearm. Allow for roughly 5 mm of extra length on either end, as the plaster shrinks when wet. The excess wet plaster on the ends will be folded over to create smooth edges. Measure and mark an opening on the plaster for the placement of the thumb through the splint. Cut out the plaster to accommodate the thumb. See the video below.

  Measuring dry plaster for radial gutter splint. Video courtesy of Kenneth R. Chuang, MD.
• If prefabricated fiberglass is used, the stockinette and padding steps can usually be skipped. In this case, follow the manufacturer recommendations.
• Submerge the plaster in clean, room-temperature water. Allow all the bubbles to escape. This starts the lamination process of the plaster and allows the layers to bond together. Squeeze out the excess water. Use a milking action with the fingers to strip out the remaining water. Then, lay the plaster on a flat surface or dry towel and smooth out wrinkles and folds. This allows for further bonding of the plaster layers. See the video below.

  Wetting the plaster. Video courtesy of Kenneth R. Chuang, MD.
• Apply the wet plaster, over the padding, to the lateral or radial surface of the forearm. The plaster should extend from the second distal interphalangeal joint to the proximal third of the forearm. Fold outward any excess plaster on the ends. The underlying stockinette and padding should then be folded outward on both ends, creating smooth edges. See the video below.

  Applying wet plaster for radial gutter splint. Video courtesy of Kenneth R. Chuang, MD.
• Apply the bandage wrap over the wet plaster. Start distally, at the distal interphalangeal (DIP) joint of the second and third digits, and wrap proximally. Cut an adequate hole for the thumb. The thumb and fourth and fifth digits should be left free. Avoid wrapping too tightly. See the video below.

  Applying bandage wrap for radial gutter splint. Video courtesy of Kenneth R. Chuang, MD.
• While the plaster is still wet, mold the splint into the desired shape. The wrist and hand should be in a neutral position. Extend the wrist 15-25°, abduct the thumb, and flex the metacarpophalangeal joints to 70°. When immobilizing metacarpal neck fractures, flex the MCP joints to 90°. The hand, wrist, and forearm should remain immobile until the splint is dry. Advise the patient that he or she may feel some warmth released from the plaster as it dries. However, if the heat becomes too intense, unwrap the splint and remove the plaster immediately, since thermal burns can occur. See the video below.

  Molding the radial gutter splint. Video courtesy of Kenneth R. Chuang, MD.
• Check for neurovascular function and capillary refill after the splint has dried. Recall that the median nerve provides sensory function to the palmar side of the thumb, second, third, and lateral half of the fourth digits and, dorsally, to the distal half of the second and third digits and the lateral half of the fourth digit. The ulnar nerve provides sensory function to the palmar and dorsal aspects of the fifth digit and the medial half of the fourth digit. The radial nerve provides sensory function to the dorsal surface of the hand and to the web space between the first and second digits. Remember to check motor function, as well. Wipe away any plaster that may have dropped onto the patient's skin. See the video below.

  Test neurovascular function and capillary refill. Video courtesy of Kenneth R. Chuang, MD.
• Deliver appropriate aftercare instructions.

  • Instruct the patient to rest, elevate, and ice the injured limb.
  • Instruct the patient to remove the splint and return immediately, or go to an emergency department, if he or she experiences weakness or numbness, color change (pale or bluish), increasing pressure or pain, or spreading redness or streaking.
  • Keep the splint clean and dry.
  • Do not stick any items into the splint. Patients can be tempted to use sticks, pens, or hangers to scratch an itch. Advise the patient that sticking objects into the splint can wrinkle the padding and lead to pressure sores or cause a break in the skin and lead to an unattended infection.
  • Arrange for follow-up with a consultant, usually in 2-7 days, depending on the reason for the splint.
  • If the patient received any sedation or opioids, advise against driving or alcohol consumption. See the image below.Radial gutter splint. Image courtesy of Kenneth R. Chuang, MD.

• To assist in achieving neutral position of the hand and wrist, some physicians advocate having the patient hold a can or a bandage wrap. Alternatively, the patient can imagine holding a wine glass. With either method, maintain the wrist at 15-25° extension.
• For injuries or reductions that require shorter drying times, faster-setting plaster is available (eg, Specialist Extra Fast Setting Plaster, which sets in 2-4 minutes). However, as the plaster dries faster, the risk of thermal injury increases. For most splints, regular plaster (eg, Specialist Fast Setting Plaster, which sets in 5-8 minutes) is appropriate.
• Consider prescribing an antihistamine (eg, Benadryl) for itching. However, if the itching persists or worsens, the splint should be reevaluated for complications.
• Note that some orthopedic surgeons recommend a volar splint instead of a radial gutter splint for angulated neck fractures of the second and third metacarpals. Check with the orthopedist who performs follow-up care for the type of splint he or she recommends.
• A radial gutter splint is often applied for uncomplicated metacarpal fractures. When a metacarpal fracture is present, a clinical examination for malrotation should also be performed. With the second through fifth fingers slightly flexed, the nail beds of adjacent fingers should lie in the same plane. With 90° flexion of the metacarpophalangeal (MCP) and proximal interphalangeal (PIP), and with distal interphalangeal (DIP) extension, the second through fifth fingers should point toward the scaphoid. It may be useful to compare with the unaffected hand. In the second and third metacarpal, 10° of angulation are acceptable; in the fourth metacarpal, 20° of angulation are acceptable; and in the fifth metacarpal, 30° of angulation are acceptable. Higher degrees of angulation often require surgery.
• The median nerve can be compressed by the application of a radial gutter splint. In the conventional anatomical position with the palms facing anteriorly, the lateral side of the fourth digit is the radial side. The median nerve provides sensory function to the palmar side of the thumb and second and third digits and the lateral half of the fourth digit and, dorsally, to the distal half of the second and third digits and the lateral half of the fourth digit. Any numbness or weakness in this distribution is suggestive of median nerve compression and should prompt splint removal with a subsequent neurovascular examination. Immediate consultation to the departments of orthopedics or hand surgery should be considered if symptoms do not resolve.

• Thermal burns:^[4] Patients can expect some warmth as the plaster dries. However, if the patient experiences intense heat or any pain, remove the plaster immediately, as thermal burns can occur.

  • As more layers of plaster are used, more heat is produced.^{[5, 6]}
  • Use clean, room-temperature water. Water that is dirty or too warm accelerates setting time and increases the heat produced.^[6]
  • Do not wrap towels or blankets around the splint to shorten drying time. This produces excess heat.
• Pressure sores: Provide extra padding to bony prominences. When wrapping the cotton padding, avoid creases. When creases occur, smooth them out or unwrap and rewrap, as needed. When molding the wet plaster, use broad-based pressure. In other words, do not use the fingertips; rather, use the entire palmar surface of the hands and fingers to mold the plaster.
• Contact dermatitis: See Contact Dermatitis.
• Ischemia and neurovascular compromise: These complications may be caused by increased pressure from swelling. If moderate to significant swelling is anticipated, cut the cotton padding lengthwise along the medial or ulnar side of the forearm before application of the wet plaster to the radial side. This allows for expansion of the padding. If using tape to secure the outermost bandage wrap, do not tape circumferentially.
• Decreased range of motion due to immobilization: Advise the patient that, depending on the extent and nature of the initial injury, he or she can often expect long-term pain, arthritis, stiffness, and decreased range of motion, despite best care practices. The aftercare of such injuries often requires physical therapy.