Radial Gutter Splint: Indications, Procedure and Care

Last Updated on November 5, 2025

A radial gutter splint is an immobilization plaster splint or device designed to stabilize injuries involving the index and middle fingers and the radial side of the hand. Radial Gutter splint is applied on the radial aspect of the forearm and sandwiches the index and middle fingers to provide both volar and dorsal support.

It derives its name from the “gutter” formed along the radial border of the forearm and hand, which cradles these two digits and the corresponding metacarpals. By immobilizing the radial column and leaving the ring and little fingers free, it balances fracture stability with hand function, allowing patients to retain some grip and opposition capacity.

Clinically, this splint is used for nondisplaced or minimally displaced fractures and for temporary immobilization before definitive fixation. It is also used postoperatively for tendon repairs or fixation protection. Compared with complete circumferential casts, a radial gutter splint permits swelling accommodation, easier inspection, and reduced risk of compartment pressure.

Anatomy and Biomechanics

The radial gutter splint is designed around the index and middle fingers, which are closely linked through the common extensor mechanism, intertendinous connections, and parallel metacarpal alignment. Their movements are interdependent, and immobilizing one without the other can create rotational stress or loss of alignment at the fracture site.

The second and third metacarpals behave as a relatively rigid unit compared with the more mobile ulnar rays (fourth and fifth metacarpals). During power grip and pinch activities, this rigid radial unit provides stability, while the ulnar side of the hand contributes to cupping and adaptability.

Therefore, immobilizing the index and middle fingers together minimizes rotational and angular deforming forces on fractures of the index or middle metacarpal and proximal or middle phalanges.

The splint extends from the proximal forearm to just beyond the distal interphalangeal joints of the index and middle fingers. It supports the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints in controlled flexion.

This prevents displacement by limiting active flexor pull. At the same time, it keeps the thumb, ring, and little fingers free, maintains balance, and facilitates motion in unaffected digits, helping reduce stiffness and making the hand more usable in the splint.

Indications of Radial Gutter Splint

The radial gutter splint is indicated for fractures and soft-tissue injuries that involve the index and middle fingers or the radial side of the hand. The splint provides sufficient stability for nondisplaced or minimally displaced fractures, allows swelling to subside, and facilitates early inspection and follow-up care.

• Metacarpal Fractures: Second and third metacarpal shaft or neck fractures that are stable or minimally displaced.
• Phalangeal Fractures: Proximal or middle phalanx fractures of the index and middle fingers, provided alignment is acceptable.
• Soft-Tissue and Tendon Injuries:
  • Extensor or flexor tendon repairs involving the index or middle finger.
  • Collateral ligament or volar plate injuries requiring restricted MCP or PIP motion.
• Temporary Immobilization: Following internal fixation of fractures or percutaneous pinning. It is also used as a temporary immobilizer before definitive surgical fixation in acute trauma when swelling is significant.
• Rehabilitation: For protection during the early mobilization phase following fixation or tendon repair.

Thus, the radial gutter splint is the preferred method of immobilization for stable radial-sided hand injuries.

Contraindications

The radial gutter splint should be applied only when fracture stability, soft-tissue condition, and limb perfusion permit safe immobilization. It should generally be avoided in the following situations

• Unstable or Comminuted Fractures: Fractures that are grossly unstable, markedly displaced, or comminuted are not suitable for simple splint immobilization.
• Open Fractures: If there are open wounds, skin loss, or infection at or near the splinting area, direct application may cause maceration or delay wound healing.
• Impending Compartment Syndrome: Splinting is contraindicated in evolving compartment syndrome or when significant forearm or hand swelling is anticipated.
• Peripheral Vascular Disease or Neuropathy: Conditions that impair circulation or sensation increase the risk of unnoticed compression or ischemia beneath the splint.

Procedure of Radial Gutter Splint Application

Position of Immobilization

Correct positioning is the cornerstone of effective radial gutter splinting. The goal is to maintain the hand in the intrinsic plus position, which preserves joint congruency and prevents collateral ligament shortening.

How is the Radial Gutter Splint Positioned?

The hand is in an intrinsic plus position

• Wrist: 20–30° extension, as this position relaxes the flexor tendons and prevents them from exerting a flexion pull.
• Metacarpophalangeal (MCP) joints: Only those of the index and middle fingers are immobilized in 70–90° flexion. This maximally stretches the collateral ligaments of the MCP joint, which prevents later contracture and stiffness
• Proximal interphalangeal (PIP) joints: 5–10° flexion
• Distal interphalangeal (DIP) joints: Slight flexion (natural resting posture), as slight flexion keeps the extensor mechanism balanced and reduces the risk of extensor lag.
• Thumb, ring, and little fingers: These are left free

Procedure of Application

Materials Needed

• Padding Materials: Stockinette, cotton, or orthopedic foam
• Splint Material: Plaster of Paris (POP) bandages or Fiberglass bandages
• Securing Material: Cotton bandages or crepe bandage to hold the splint in place
• Ancillary Items: Scissors for trimming and tapering edges, water in basin. gloves, protective apron, Marker or tape to label

In prefabricated plaster applications, the stockinette and padding are not required. [For the application of  this plaster, just follow the manufacturer’s advice]

Preparation

Radial gutter splinting is usually tolerated without anesthesia. However, anesthesia or analgesia may be required in cases where a reduction is required, such as malrotated or angulated fractures (10 degrees in the 2nd and 3rd metacarpal. In such cases, the following may be used alone or in combination

• Hematoma block or nerve block
• Procedural sedation
• Administration of oral or intravenous pain medications like NSAIDs or opioids

The correction of the deformity may be needed in malrotated fractures and angulations beyond acceptable limits, which are 10 degrees in the second and third metacarpals (Acceptable limit is 20 degrees in the fourth metacarpal, 30° in the fifth]

Patient Positioning

A complete neurovascular examination should be performed after the splint has been applied.

• Seat the patient comfortably with the forearm resting on a table, elbow flexed to 90°, and the hand in mid-pronation.
• Inspect for wounds, swelling, or deformity, and cover open injuries with a sterile dressing before splinting.
• Explain the procedure to the patient to ensure relaxation during molding.

Padding

• Apply a stockinette extending from the proximal third of the forearm to beyond the tips of the index and middle fingers. Keep thumb, ring finger, and little finger free.
• Wrap soft padding evenly, ensuring extra protection over the radial styloid, MCP heads, and proximal phalanges.
• Avoid wrinkles and overlapping ridges.

Preparation of Splint

The plaster length is measured from the proximal third of the forearm to the distal IP joint. Make a splint of plaster of Paris using a 4-inch bandage and 10-14 layers thick, allowing 5mm of extra length on either end to allow for plaster shrinkage when wet.

• Prepare 10-14 layers of Plaster of Paris bandage (or equivalent fiberglass layers) splint
• The extent is from the proximal third of the forearm to just beyond the distal interphalangeal joints of the index and middle fingers.
• The width should roughly match the radial border of the forearm to the midline of the dorsum of the hand. Prepare the splint so that the index and middle fingers can be sandwiched between the splint while the other digits are free. A longitudinal slit in the distal end can easily achieve this (as shown in the image below). Some people prefer making a hole in the splint to keep the thumb out when the splint is applied.
• Immerse in water, squeeze gently, and lay flat to remove air bubbles.
• Place the damp splint along the radial aspect of the forearm, continuing over the dorsum and sides of the index and middle fingers.

Application of Splint

• Align the hand in the intrinsic plus position:
  • Wrist 20–30° extension
  • MCP joints 70–90° flexion
  • IP joints are slightly flexed
• Mold the splint firmly along the natural curvature of the metacarpals and web space between the index and middle fingers, avoiding compression of the radial styloid.
• Hold the position until the plaster sets (usually 5–7 minutes).
• Once hardened, secure the splint using a spiral elastic bandage, starting from the hand and moving proximally. Some people prefer securing a wet splint for better conformity and contour accommodation.
• Keep the fingertips visible for continuous observation.
• Recheck and document distal perfusion and sensation after fixation.
• Support the limb until the splint hardens completely.
• Elevate the hand on a pillow or sling to minimize swelling during the first few hours.

After the splint has been applied, confirm that the splint maintains the desired position without pain or excessive tightness. Obtain post-splint radiographs to confirm maintained reduction in fracture cases.

Aftercare and Follow-up

[Read more on plaster care]

Call the patient back for a recheck after 48 hours and further as necessary. The period immediately after application is critical, as swelling, pressure, or poor compliance can quickly convert an effective immobilization into a harmful one.

Review at 3–5 days to reassess swelling and comfort, and readjust if necessary. Repeat radiographs at 7–10 days for fracture cases to confirm maintained alignment. Use oral analgesics and cold compresses intermittently for the first 48 hours.

The patient should be instructed to take care of the limb by paying attention to

• Limb Elevation: Keep the hand elevated above heart level for the first 24–48 hours using a sling or pillow support. Avoid dependent positioning, particularly in the early post-injury phase. Elevation minimizes edema, reduces throbbing pain, and prevents vascular congestion beneath the splint.
• Finger Movement: Encourage active movement of the thumb, ring, and little fingers several times per hour. Avoid any attempt to flex or extend the splinted index and middle fingers.
• Skin and Circulation Checks: Instruct the patient to observe for excessive pain, numbness, coldness, or discoloration of the fingertips. Check capillary refill regularly (fingertip blanches and returns to pink within 2 seconds). If any signs of tightness, pallor, or paresthesia appear, loosen the bandage immediately and seek medical review. A spreading redness or streaking should be reported immediately, too.
• Hygiene and Splint Care: Keep the splint dry and clean; avoid immersing it in water. Do not insert objects to scratch or relieve itching. Reinforce or rewrap if the bandage becomes loose as swelling decreases.

Complications

Although the radial gutter splint is generally safe, complications may arise. Understanding their mechanisms helps prevent long-term functional loss.

• Pressure Sores: Excessive tightness, uneven padding, or moisture beneath the splint may lead to sores, especially over bony prominences. Burning sensation or unrelenting pain should alert the physician.
• Neurovascular Compromise: Circumferential constriction or increasing edema after application may lead to neurovascular compromise by compression of digital arteries or nerves. pain, paresthesia, and pallor. The plaster is often opened to relieve the compromise and further management.
• Joint Stiffness and Tendon Adhesions: Immobilization in nonfunctional posture or prolonged use may cause flexor and extensor tendons to adhere to surrounding tissues. Immobilization in the intrinsic plus position and mobilization of fingers often prevent it
• Residual Weakness and Grip Loss: It is often seen as a failure to restore motion and strength after immobilization. It occurs as prolonged disuse causes muscle atrophy, stiffness, and reduced coordination between the radial and ulnar columns. Early rehabilitation, strengthening, and graded motion once the splint is discontinued can manage the issue.

References

• Rockwood, C. A., Green, D. P., Bucholz, R. W., & Heckman, J. D. (2015). Rockwood and Green’s Fractures in Adults (8th ed.). Philadelphia: Lippincott Williams & Wilkins.
• Adams, B. D., & Murray, J. F. (2006). Hand Splinting: Principles and Methods. St. Louis: Mosby.
• Playe SJ, Filener WS. Principles of Splinting. Hart RG, Rittenberry TJ, Uehara DT. Handbook of Orthopaedic Emergencies. Philadelphia, Pa: Lippincott-Raven; 1999. 92-115.
• Leggett JH, Ladd M, Short RE. Hand Splint. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470462/