Novel use of IV cannula stylet for tibiotarsal fracture repair in a cockatiel

Introduction

Bone fractures are common in both wild and captive birds (Fix and Barrows, 1990; Houston, 1993) [3,7] . Tibiotarsal fractures are among the most common fractures seen in pet birds and often are associated with mishandling by human caretakers, cage-related trauma, and injuries caused by another pet in the household (Harcourt-Brown, 2002) [5] . A study on avian fractures during kite festival recorded that out of total limb fractures in birds, 20% had femur fractures while 50% had tibiotarsus fractures (Kothambdi, 2014) [9] . In order to treat orthopedic conditions in birds, nonsurgical methods such as external coaptation, or surgical means including internal and external fixation procedures, or a combination of both are typically used. External coaptation is a cost-effective and rapid technique that provides good immobilization of the fracture site. It can be used effectively for small sized birds for which anaesthesia and surgical facilities are not available (Redig, 1986) [11] . In this approach, however, periosteal callus predominates despite the long duration of immobilization and it may even contribute to muscle wasting.

The advantages of open reduction include reduced soft tissue trauma, visualization of the fracture site and removal of interposed soft tissues. The direct tissue manipulation, however, can compromise blood supply and produce direct tissue damage which increases the healing time and likelihood of unsuccessful function post-repair (Howard and Branson, 1994) [8] . Radiography is a useful entity as a general approach for the interpretation of skeletal disorders, classification and grading of fractures in birds. Similarly, it's a useful tool for finding postoperative status of fracture fragments, evaluating fracture healing, periosteal reaction and soft tissue changes (Ritchie et al., 1994) [12] .

Materials and Methods

A 2-year-old Lutino Cockatiel (Nymphicus hollandicus), weighing approximately 90 g, was presented to the small animal OPD, Department of Veterinary Surgery and Radiology, Veterinary College Hebbal, Bengaluru, with the history of non-weight-bearing lameness in the left hindlimb following accidental trauma. According to the owner, the bird had gotten its leg entangled between cage bars and fractured it while attempting to free itself. The bird was brought to the hospital within 24 hours of injury. On clinical examination, the bird was bright, alert, and responsive. There was noticeable swelling and limb deformity at the midshaft of the left tibiotarsus. The bird exhibited signs of discomfort while attempting to perch, and the affected limb was hanging loosely with clear absence of weight-bearing. There were no external wounds or signs of hemorrhage but severe soft tissue swelling was noticed at the site [Fig. 1]. Palpation revealed crepitus and instability, indicative of a complete fracture. Radiographic evaluation under manual restraint confirmed a short oblique, complete, midshaft fracture of the left tibiotarsus [Fig. 2]. No comminution or joint involvement was observed. Based on the location, nature of the fracture, and the size of the bird, intramedullary pinning was chosen as the ideal method for stabilization. After owner consent, the bird was anesthetized in an induction chamber using sevoflurane, and anesthesia was maintained with a face mask throughout the procedure. A heating pad was used to prevent hypothermia. The surgical site was prepared aseptically by plucking feathers over the tibiotarsal region and applying 7.5% povidone-iodine scrub solution.

A 22G intravenous cannula stylet, pre-sterilized and rigid, was selected for use as an intramedullary pin. A small stab incision was made between the cranial and medial tibiotarsal tuberosity, and the stylet was introduced using a normograde technique. The stylet was gently advanced through the proximal metaphysis into the medullary cavity. The bone fragments were aligned using manual traction and digital manipulation without opening the fracture site. Once alignment was achieved, the stylet was advanced into the distal medullary canal [Fig. 3]. The pin was trimmed close to the skin, and due to the minimal incision and lack of hemorrhage, no sutures were required. A post-operative radiograph was taken to confirm correct placement of the implant [Fig. 4], and a sterile bandage was applied over the site. The bird recovered smoothly from anesthesia and resumed preening within an hour postoperatively.

Postoperative care included administration of Enrofloxacin (15 mg/kg PO SID for 5 days) and Meloxicam (0.5 mg/kg PO SID for 3 days). The owner was advised to restrict the bird's movement for the week following surgery.

Results and Discussion

Recovery was smooth, and the bird began to perch and bear partial weight by 7 th post-operative day. Follow-up radiographs on 14 th post-operative day showed callus formation and stable alignment. By 21 st post-operative day, radiographic union was evident, and the intramedullary stylet was removed manually without anesthesia. Bush et al (1976) [1] studied that callus formation appeared to be similar in birds and mammals. Endosteal callus provided rapid stabilization in bones that were properly aligned. Periosteal callus formation was minimal if the bones are rigidly fixed. Another study observed that the healing of bones was a combination of primary healing, bone to bone healing through Haversian system with minimal callus formation (Doneley, 2011) [2] . This could only be achieved with rigid fixation and perfect bone apposition. Endosteal callus formation occurred rapidly where bones were well aligned. This highlights the importance of internal fixation in avians.

Multiple surgical techniques for repairing tibiotarsal fractures in birds have been described. The most commonly described technique involves the use of external skeletal fixation, typically in a type II construct (Meij et al., 1996) [10] . Other methods include the use of interlocking nails (Hollamby et al., 2004) [6] and titanium microplates (Gouvea et al., 2011) [4] . This case showcased the practicality of using a sterile IV cannula stylet as an orthopedic implant in small birds. Given their narrow medullary canals, alternatives like K-wires are often too large. The IV stylet offered the required rigidity and biocompatibility, and was a promising alternative.

Conclusion

The use of a 22G intravenous cannula stylet for the intramedullary fixation of a tibiotarsal fracture in a Cockatiel was successful, leading to complete recovery and return to normal limb function. This method is recommended as a viable alternative in cases where traditional implants are unavailable or impractical due to the bird's size.

References

1. Bush M, Montali RI, Novak RG, James FA. The healing of avian fractures: a histological xeroradiographic study. Am Anim Hosp Assoc J. 1976;12(6):768-773.
2. Doneley B. Avian medicine and surgery in practice. 2nd ed. London: Manson Publishing Ltd.; 2011. p. 1-336.
3. Fix AS, Barrows SZ. Raptors rehabilitated in Iowa during 1986 and 1987: a retrospective study. J Wildl Dis. 1990;26(1):18-21.
4. Gouvea AS, Alievi MM, Noriega V, Isis-dos SD, Pinto TM, De Menezes CLM, et al. Titanium microplates for treatment of tibiotarsus fractures in pigeons. Ciencia Rural. 2011;41(3):476-482.
5. Harcourt-Brown NH. Orthopedic conditions that affect the avian pelvic limb. Vet Clin North Am Exot Anim Pract. 2002;5(1):49-81.
6. Hollamby S, Dejardin LM, Sikarskie JG, et al. Tibiotarsal fracture repair in a bald eagle (Haliaeetus leucocephalus) using an interlocking nail. J Zoo Wildl Med. 2004;35(1):77-81.
7. Houston DC. The incidence of healed fractures to wing bones of White-backed and Rüppell's Griffon Vultures Gyps africanus and G. rueppellii and other birds. Ibis. 1993;135(4):468-475.
8. Howard M, Branson RW. Orthopedic surgical techniques. In: Ritchie BW, Harrison GJ, Harrison LR, editors. Avian medicine: principles and application. Abridged ed. Lake Worth (FL): Wingers Publishing; 1994. p. 1137-1169.
9. Kothamdi UY. Studies on fracture repair in birds during kite flying festival. Anand (Gujarat): Anand Agricultural University; 2014.
10. Meij B, Hazewinkel H, Westerhof I. Treatment of fractures and angular limb deformities of the tibiotarsus in birds by type II external skeletal fixation. J Avian Med Surg. 1996;10(3):153-162.
11. Redig PD. Basic orthopedic surgical techniques. In: Harrison GJ, Harrison LR, editors. Clinical avian medicine and surgery. Philadelphia: WB Saunders Company; 1986. p. 596-598.
12. Ritchie B, Harrison G, Harrison L. Avian medicine: principles and applications. 1st ed. Lake Worth (FL): Wingers Publishing; 1994. p. 1066-1080.