Simple avian surgical procedures (Proceedings)

Treating dermal injuries, fracture stabilization, stabilization of fracture sites after internal orthopedic repair, joint injuries and prevention of self trauma are common reasons bandages are used on avian patients. Bandages function to apply pressure to reduce dead space, swelling edema and hemorrhage; protect the wound from pathologic microorganisms; immobilize the wound and underlying fractures; protect the wound from desiccation and additional trauma from abrasions or self-mutilation; absorb exudates and help debride the wound surface; and provide comfort for the patient.1 Although bandages may be less stressful to apply than internal fixation of a fracture it is imperative that the proper application technique be used to prevent increased trauma to the affected area. Bandages that are applied incorrectly may not help the condition of the patient, if applied too tight, this will restrict blood flow to the distal extremity, if immobilization of the joints above and below the fracture is not achieved, the possibility of a nonunion significantly increases. Often what first appears to be a simple technique to apply is not that simple but requires skill, the proper materials, patience, a properly restrained patient and an understanding of the forces to be controlled by the bandage.

Common bandage materials used on avian patients include Vet-Wrap (3M Animal Care Products, St. Paul, MN), adaptic (Johnson & Johnson, New Brunswick, NJ), 4 X 4 and 2 X 2 gauze sponges, white cloth tape, cast padding, Hexcelite (Hexcel Medical Co., Dublin, CA), syringe cases, aluminum rods and roll gauze. One of the most important aspects of bandaging avian patients is that most of the bandage materials listed above do not come in sizes applicable to patients that weigh less than 300 grams, especially passerines that weigh less than 30 grams. Modification and manipulation of the smallest size of the bandage material mentioned above will be sufficient for proper application on the small avian patients. Vendors do not manufacture and sell specific splints for the different avian species or for animals the size of most pet birds. Therefore veterinarians are required to use their skills at manufacturing splints out of Hexcelite, syringe cases, aluminum rods or some other ridged material. To fabricate a syringe case splint, a dremel tool is required to cut and shape the splint to the size of the patient's anatomy that needs to be immobilized. Hexalite, a thermal sensitive material that becomes malleable when placed in hot water then hardens at room temperature in the shape of the injured anatomical area. Ultraviolet (UV) dental acrylic can be used in a similar manner as Hexalite, but cures hard when exposed to the UV light generated by a UV gun. Eye protection must be worn by veterinarians and hospital staff when using UV dental acrylic curing instrument.

The owner of bandaged avian patients must understand the importance of monitoring the bandage and affected area and to make sure they make the required follow up visits for reevaluation. Veterinarians, veterinary technical staff and owners should monitor the bandage site for slippage of the bandage/splint, swelling distal to the bandage, non-use of the limb or a regression of ability to use a limb, irritation or picking at the bandage site, and tissue abrasions at contact surface sites with the bandage. If any of the above listed conditions is occurring then the bandage needs to be removed, area below and around the bandage evaluated and the bandage reapplied if necessary.

Figure-of-Eight Wing Bandage

One of the most commonly used external coaptation bandages and in my experience one of the most incorrectly applied bandages. The figure-of-eight bandage is a bandage that is applied to the wing and can be used to immobilize fractures distal to the elbow, maintain the wing in position when an intraosseous catheter is in place within the distal ulna or maintain bandages in place when treating dermal lesions. The supporting bandage material used is dependent on the condition of the underlying tissue and/or bones. If there is a closed fracture involving the ulna or radius underlying cast padding may be used to support the outer layer of non-stick wrap (Vet-wrap). If there is an incision, open wound or abrasion, the area is cleaned, treated and a non-stick gauze pad (Adaptic) is placed over the affected area then supported with 2X2 or 4X4 gauze sponges and held in place with an elastic gauze wrap (Kling®, Johnson & Johnson, New Brunswick, NJ) and an outer layer of non-stick wrap. These bandages may be changed daily or weekly depending on the injury and patient condition.

The difficulty in placing this wrap on the wing is keeping the bandage in place and incorporating the humerus in the bandage. Placement of the wrap should start at the axillary area where the wing attaches to the body. The bandage material is then brought over the dorsal surface of the wing toward the flexed carpal area. The wrap is then maneuvered under and around the ventral surface of the flexed carpal area ending up on the top of the wing. As the bandage material is brought back, caudally over the dorsal surface of the wing, the top part of the 8 is formed. Continue bringing the bandage material caudally and wrap under the primary feathers going back to the initiation point, completing the figure-of-8. By wrapping the bandage in this manner one can be assured of incorporating the humerus into this wrap. The figure-of-eight bandage is complete when the above instructions are repeated 3 or 4 times securing the wing. If the humerus is to be stabilized a body wrap can be incorporated into bandage. Care must me taken, if a body wrap is used, not to make the bandage too tight which may hinder the patient's ability to breath. If the body wrap is placed too far caudal on the body the patient's feet may have a tendency of getting caught in the bandage or they may not be able to extend their legs. When finished the non-stick bandage should be held in place with a small piece of adhesive tape.

Syringe Case Splint

The syringe case splint is an external coaptive device that is best used for birds that have been diagnosed with a tibiotarsal fracture or tarsometatarsal fracture. The syringe case and corresponding wrap help immobilize the joints and fracture site for healing to occur without having to surgically repair the fracture. Surgical correction increases the possibility of collateral damage that may impair the function of the affected limb. A syringe case is selected based on the size of patient's leg that needs to be immobilized. Once selected, a Dremel tool with a cutting bit is used to remove the flared top part of the syringe case and half of the barrel leaving the flat base intact. If the splint is to be placed on a parrot that has been diagnosed with a tarsometatarsal fracture, notches can be etched on the side of the case where it comes into contact with the base, for rear toe placement. If the splint is to be placed on a passerine or raptor species that has been diagnosed with a tarsometatarsal fracture then a hole can be made in the back of the syringe to accommodate the first digit. None of the above modifications for toes have to be made for tibiotarsal fractures. For tibiotarsal fractures the top of the back of the splint should be ground into a semicircular pattern to accommodate the Flexor cruris medialis muscle. Cotton is glued on the base of the splint and 4X4 gauze sponges are placed in the inside of the splint and over the back, held in place with non-stick bandage material (Vet-Wrap). This will soften the splint thereby protecting the bird's skin from the sharp edges of the splint.

To properly apply the splint the feathers should be plucked where the splint will come into contact with the body part. Tape stirrups are placed on the lateral and medial aspects of the limb along the affected tibiotarsus or tarsometatarsal bone. Cast padding is then used to wrap the leg for increased immobilization in the splint. The splint is then applied over the cast padding and the tape stirrups are then taped to the side of the splint. Two pieces of adhesive tape are then used to firmly attach the barrel of the splint to the leg. One of the most important points of properly applying this splint and assuring that it will remain in place is a cruciate tape pattern over the distal part of the limb as it rests in the base of the splint. This cruciate tape pattern goes over and around the splint before coming back over the top and back around on the opposite side. The limb should be securely in place and the fracture reduced as much as possible before applying the cruciate tape pattern. The splint and leg are then wrapped with a non-stick bandage material (Vet-Wrap) which is held in place with a piece of adhesive tape. The bandage should be reassessed regularly to check for swelling in the distal extremities and skin abrasions generated by the splint edges.

Tape Splint

The tape splint is a simple splint and is best used on birds that weigh less than 60 grams. Although in certain references it states that the splint can be used in birds weighing up to 150 grams with supporting material placed under the tape, a simple tape splint works best on the lightest of avian patients.2 The tape splint is recommended for the same type of fractures as those listed for syringe case splints. In light weight birds such as finches, canaries and budgerigars feathers do not have to be plucked over the tibiotarsal area to place the splint. An appropriate sized piece of adhesive tape is placed under the leg, adhering the affected area to the tape with the joint above and below the fracture incorporated in the tape area. The tape is then folded over allowing for extra tape to extend cranially and caudally from the leg. Hemostats are then used to press the tape together close to the leg thereby immobilizing the fracture site.

Ball bandages

A ball bandage is applied to the planter surface of a bird foot. This bandage allows the bird to stand while allowing minimal if any pressure to the plantar surface of the foot. Applications for the ball bandage include infectious pododermatitis, lacerations and protecting foot injuries/surgical sites during the healing process. An appropriate sized piece of gauze or cast padding is placed on the plantar surface allowing the toes to flex over the edges without touching the base. If there is a wound that needs to be treated then this step should take place before the gauze ball is put in place. While the toes are flexed over the "ball" a non-stick (Vet-Wrap) bandage material is used to wrap the foot incorporating the "ball".

Snowshoe splint

This splint is also for foot injuries, in particular toe fractures and constricted toe syndrome cases. A tongue depressor is cut to the length of the foot including the claws. Using an electrocautery unit a hole is made in the tongue depressor where the (front and back) longest claws extend. The tips of the claws fit into the holes helping to secure the foot onto the splint. Adhesive tape strips are then applied to the medial toes (front and back) and wrapped around the splint securing the foot to the tongue depressor. The splint is completed with a non-stick (Vet-Wrap) bandage material being applied over the foot and splint. A small piece of adhesive tape holds the non-stick bandage material in place.

Duck shoe splint

Duck shoe splints are used waterfowl that have foot injuries. Coat hanger wire or small gauge aluminum rod material is bent to the form of the waterfowl patient's foot extending up the tarsometarsal bone. The splint is padded with cast padding and wrapped in waterproof tape. The splint is applied to the extended foot, being held in place with adhesive tape. Two full width 1" adhesive tape strips are wrapped around the tarsometasal bone and that part of the splint that extends up the leg. The bandage is completed with a non-stick tape material being applied over the foot, splint and leg.

Wet-to-dry bandage

These bandages are recommended for skin wounds that have to close by secondary intention, encouraging the natural healing mechanisms of epithelialization and contraction. Wet-to-dry bandages are easy to apply, provide a means of debridement, allow the use of topical antimicrobial solutions, and provide a moist environment for eptithelialization.3

Although normal saline is the preferred wet solution, a weak solution of chlorhexidine diacetate (Nolvasan®, Fort Dodge, Labs Inc., Fort Dodge, IA) at approximately 0.1%in water for the primary layer of standard 4 X 4 gauze sponges may be used.3 Chlorhexidine diacetate solutions of greater than 0.5% have been shown to retard granulation and inhibit epithelialization.4 The secondary, absorptive, dry layer should consist of dry 4X4 gauze sponges. A non-stick (Vet-Wrap) bandage material is used for the tertiary layer to hold the first 2 layers in place. The bandage should be removed and reapplied daily until a healthy granulation bed forms. At that point the wetting agent can inhibit the progress of epithelialization and contraction.3 To aid the healing process of the granulation bed an occlusive, non-adherent bandage should be applied until epithelialization and contraction are complete.

References

1.Swaim SF, Wilhalf D: The physics, physiology and chemistry of bandaging open wounds. Comp Cont Ed 7:146-156,1985.

2.Degernes LA: Trauma medicine, in Avian Medicine: Principles and Application, Ritchie BW, Harrison GJ, Harrison LR (eds): Lake Worth, FL, Wingers Publishing, 1994, pp 417-433

3. King WW, Tully TN: Management of a large cutaneous defect in a moluccan cockatoo. Proceedings of the Association of Avian Veterinarians, Nashville, TN, 1993, pp 142-145

4. Lee AH, et al: Effects of chlorhexidine diacetate, povidone iodine and polyhydroxydine on wound healing in dogs. J Amer Anim Hosp Assoc 24:77-84, 1988