External coaptation can protect and support injured bones and joints. Splints can be used temporarily until surgery can be performed or for 1 to 2 months to support a healing limb. External coaptation is best for fractures that are distal to the elbow/stifle, simple, reducible, transverse, greenstick (or have a paired bone that remains intact) or in pediatric patients (due to the rapid healing potential of these patients) and is typically not recommended for treatment of comminuted, articular, or oblique fractures because it cannot provide rigid stability. Other methods of stabilization (eg, external skeletal fixation) can be used for open fractures, which may require frequent wound care.
Risk for Complications
All bandage types can cause significant soft tissue complications. In one study that evaluated outcomes following cast placement, 63% of patients developed soft tissue injury from the bandage.1 Pressure points (eg, caudal olecranon, carpal pad, dewclaw, caudal calcaneus, medial/lateral metatarsal-phalangeal joint) should be protected; proper bandage application techniques should be followed; and close supervision and communication should be maintained to ensure pet owner compliance. Pressure points can be protected by pre-emptively adding a small donut of cast padding or foam (Figure 1) between the bony prominence and the bandage. Additional protection can be provided by using well-fitted, conforming cast padding without wrinkles, applying padding with a 50% layer overlap, and ensuring layers are slightly thicker around bone regions and thinner around muscular regions.
A donut made from cast padding (A) or foam (B) can be placed between a bony prominence and a bandage to decrease risk for bandage sores.
Bandage Length
Bandage length should be determined based on the location of the bone or joint to be stabilized. When stabilizing a bone fracture, the proximal application of the bandage should extend beyond the joint above the fractured bone. Distal application should include the paw and toes in the bandage to prevent swelling from a tourniquet effect and/or a dorsal pressure sore where weight-bearing toes extend. The distal nails of the third and fourth digit should be left visible to assess for digital swelling or splint slippage.
Bandage Material
The rigid portion of the splint can either be premade (Figure 2) or custom molded to the limb. Molded splints may be better tolerated, as they are customized to the patient’s anatomy and therefore shift less and have lower risk for soft tissue injury. Fiberglass casting tape is impregnated with a moldable, resin-binding material (Figure 3) that is activated by submersion in water and cures and hardens within several minutes after conforming to the prebandaged limb.2 Alternatively, a homogeneous splinting material can be heated until soft and conformed to the prebandaged limb (Figure 4). Ridges, bunches, and sharp edges should be avoided with all bandage materials.
Premade caudal spoon splints made of metal (left) and plastic (right)
Custom-molded lateral pelvic limb splint made from fiberglass casting tape
Custom-molded lateral pelvic limb splint made from homogeneous splinting material
Bandage Changes
Routine bandage changes allow identification and treatment of complications. Bandages should be changed at least once per week depending on injury type, existing wounds, and patient age, activity level, and compliance. Prompt re-evaluation is needed if the patient appears painful or stops using the limb, the bandage becomes wet or dirty, the toes become cold or swollen, or a foul odor is identified.
Step-by-Step: Applying a Splint
What You Will Need
Gloves
Cotton balls or padding
Porous white tape
Tongue depressor
Marker
Conforming cast padding
Cotton or foam donut
Elastic gauze
Cohesive bandage/wrap
Elastic tape
Waterproof cover (eg, plastic wrap, plastic bag, IV fluid bag, boot device)
Premade splint or moldable splint material (eg, fiberglass casting tape) with nonadherent barrier
Bowl of water (if fiberglass is used)
Step 1: Provide Cushion & Protection for Pressure Points
Loosely place cotton balls or padding between the toes to provide cushion, avoiding firm wads of material that can cause interdigital pressure sores.
Step 2: Create Stirrups (Optional)
Create stirrups by applying 2 strips of porous white tape on opposite sides of the limb (either cranially and caudally or medially and laterally). Extend the tape approximately halfway up the target length of the bandage on the limb, leaving an equal length extending beyond the toes. Place a tongue depressor between the ends of the tape to prevent the strip ends from sticking together. Do not place stirrups in areas where wounds are present or place tape so tightly on the tongue depressor that the toes are compressed together.
Author Insight
Stirrup use can contribute to additional soft tissue injury during the bandaging period. Well-placed bandages typically do not require stirrups. If used, stirrups can be cut at the level of the toes during bandage changes to facilitate bandage removal and new stirrups placed directly on top of the previous ones (rather than removing tape at each visit); however, prolonged tape application may damage skin. Alternatively, adhesive remover can be used to remove stirrups at each bandage change prior to application of fresh stirrups. The skin should be carefully evaluated at each bandage change.
Step 3: Apply Cast Padding
Beginning at the toes, apply 3 to 4 layers of cast padding ascending proximally, overlapping each circumferential wrap by 50%. Conform cast padding with each pass to maintain uniformity, and apply enough tension to smooth, but not tear, material ridges. Incorporate extra padding (eg, foam or cotton donut) underneath the cast padding around pressure points. Ensure the foot and toes are included in the bandage, leaving the middle 2 toenails exposed to monitor for swelling.
Step 4: Apply First Layer of Elastic Gauze
Beginning at the toes, apply 1 to 2 layers of elastic gauze ascending proximally, overlapping each circumferential wrap by 50%. Conform this layer to the limb, applying slightly more tension around thicker soft tissue regions and slightly less tension around bony regions. Apply tension to tighten the gauze with each pass to avoid material ridges and bunching.
Step 5: Apply a Premade or Fiberglass Splint
For premade splints, place the splint on the limb (A). Ensure there are no gaps between the bandage and splint and the bandage material extends 1 to 2 inches above the splint. If the splint extends beyond this point, trim the excess material so there is no contact with the skin.
For fiberglass splints, place a nonadherent barrier (eg, toilet paper) to prevent casting tape from adhering to the gauze layer (B).
Prepare the fiberglass material by submerging the roll of casting tape into a bowl of water and squeezing out the excess water. Wearing gloves, fit fiberglass material to the site (ie, lateral, caudal, combination; C) by unrolling and stacking layers of material at the proper length. Test the bandage site for appropriate length and adequate thickness.
Apply elastic gauze to the outside of the splint to conform the soft splint material to the bandaged limb. Ensure no ridges or bumps are created. Manually shape the limb and foot to a standing angle with proper alignment of the joints before the material hardens (D). Ensure the bandage material extends 1 to 2 inches above the splint. If the splint extends beyond this point, remove the outermost layer of roll gauze, the splint, and the nonadherent barrier after the splint hardens. Trim, file, and tape the edges of the splint as needed.
Author Insight
Thoracic limb splints are often placed on the caudal or lateral aspect of the limb depending on injury severity. Pelvic limb splints are often placed laterally. Splints placed over the caudal aspect of the hock should be avoided due to increased risk for soft tissue injury over the calcaneus.
Step 6: Apply Second Layer of Elastic Gauze
Beginning at the toes, apply 1 to 2 layers of elastic gauze ascending proximally, overlapping each circumferential wrap by 50% to secure the rigid splint.
Step 7: Remove Stirrups (Optional)
Remove the stirrups (if used) from the tongue depressor; rotate the tape 180 degrees; and secure the adherent side of the tape to the bandage.
Step 8: Apply Cohesive Bandage
Beginning at the toes, apply 1 to 2 layers of cohesive bandage ascending proximally, overlapping each circumferential wrap by 50%. Do not pull the material too tightly during wrapping.
Author Insight
Unrolling and rerolling the cohesive bandage before application can help prevent excess tension.
Step 9: Apply Elastic Tape
Cut a piece of elastic tape so the toes can be accessed and apply to the palmar or plantar surface of the foot to enhance durability where the bandage contacts the ground. Place 2 marks on the bandage with a marker to note the location of the toenails and help monitor for swelling.
Author Insight
A strip of tape can also be placed at the top of the bandage on the lateral aspect to help secure the bandage but should not be applied circumferentially because of the risk for tourniquet effect. Caution is needed or elastic tape should be avoided on sensitive skin regions (eg, medial thigh) and in breeds with sensitive skin (eg, sighthounds).
Step 10: Add a Waterproof Cover
Place a waterproof cover (eg, plastic wrap, plastic bag, IV fluid bag, boot device) to provide protection against outdoor moisture and debris.
Author Insight
When the patient is indoors, the outer layer can be removed to prevent trapping sweat moisture in the bandage.