Epoxy putty external skeletal fixation in a tibiotarsal fracture of a wild choroy parakeet (Enicognathus leptorhynchus)

Abstract

Artículo de publicación ISITibiotarsal fractures are common in birds because in most birds this is the longest, most exposed bone in the leg. Transverse fractures are most common and rotational and shear forces must be stabilized in order to achieve good bone regeneration. A 230g male Slender-billed Parakeet or Choroy parakeet (Enicognathus leptorhynchus), with more than five years of age, was received with non-weight bearing lameness with 24 hours duration. X-rays were taken, and these revealed a closed, complete, non-comminuted transverse fracture of the distal diaphysis of the left tibiotarsal bone. Fixation was planned with 10-minute fast-setting epoxy putty. In order to assess the temperature of polymerization of the epoxy dough and the possibility of heat-bone necrosis, the temperature was recorded every 30 seconds for 12 minutes with three different amounts of the epoxy material in an ex vivo test. The temperature of the pieces reached a peak of 50-60°C, where the highest peak corresponds to the highest amount of material. When approximately 6g of putty were used, the peak temperature reached only 51°C. This peak changed to 58°C when 4 times more epoxy was mixed and measured. If the temperature of the pins inserted in the bone exceeds 70°C, bone necrosis could occur. In light of these results, the fracture was treated with 6 g of epoxy putty that was allowed to polymerize over a 1A 2/2 external skeletal fixation, with 1-mm pins bent at 90° and joined together with cerclage wire. At 6 weeks after surgery the bird had formed a good primary bone callus, and the external fixators were therefore removed. With this approach a satisfactory recovery of the patient was achieved with normal use of the affected limb

Osteossíntese de ossos longos em aves: Revisão

“…Fonte: Alievi et al (2001). Arias et al (2015) relataram o uso de massa epóxi como alternativa viável ao PMMA em fratura de periquito choroy selvagem (Enichognatus leptorhynchus), por atingir menores temperaturas de polimerização, diminuindo assim o risco de necrose óssea. Dal-Bó et al (2012) utilizaram fixação externa trans articular tipo II em fratura completa oblíqua com esquírola na diáfise distal de tibiotarso de gavião carrapateiro (Milvago chimachima), com colocação de três pinos no fragmento proximal e 1 no distal, além de 2 no tarsometatarso, fixados a barras acrílicas autopolimerizáveis.…”

Treatment of extremity fractures in 20 wild birds with a modified Meynard external fixator and clinical assessment of the results

“…The weight of the external fixator is a factor that makes its usage difficult. Many commercial fixator clamps are too heavy to use in birds and they are also not compatible for holding the pins that need to be used in birds (Hatt et al 2007;Arias et al 2015). From the past to the present, a great number of materials have been used in fracture treatments in birds.…”

“…Using only PMMA can form a small contact surface between the fixator and pin surface and cause instability. In order to increase the contact surface, methods such as creating roughness on the smooth pins, bending the pins 90° and covering the pins with cerclage wire before covering with PMMA have been proposed (Arias et al 2015).…”

“…The clamps of many commercial external fixators are too heavy to use in birds, especially in birds weighing less than 1 kg. In addition, they are not compatible to hold the thin pins that need to be used in birds (Hatt et al 2007;Arias et al 2015).…”