Type II ESF & IM-pin in Tibiotarsus of 3 months old Eclectus parrot; Surgery by Rob van Zon
Orthopedic problems are a common reason for birds to visit the veterinarian. Flying, especially in a non-natural environment ( cars, fences, fans, windows), frequently results in sever trauma. Also living together with humans can result in being stepped or seated on, getting stuck between doors, getting constricted in toys in cages or being used as a toy itself by other pets. And off course, the nutritional deficiencies in the majority of the psittacines in captivity, don’t help either.
Although the basics of the avian skeleton are the same as in mammals, some characteristics of the bones of birds make orthopedic problems a bit more complicated. The cortices of the bones are relatively thin and brittle, easily resulting in comminuted fractures with sharp edged fragments in cases of trauma. Combined with the absence of thick layers of protective soft tissues covering the bones, the sharp fragments easily perforate the overlying skin. Especially in the distal parts of the legs and the humerus, open fractures are common. Significant blood loss can be the result of external or internal bleeding.
While waiting for the permanent fixation,extremities of birds with fractures of the wings or legs more distally than the femur, should be bandaged immediately to protect the soft tissues and skin to more trauma caused by moving sharp fragment. Birds with excessive blood loss (big haematomas or external bleeding) should get fluid therapy for stabilizing the patient before further treatment of the fracture. As a guideline for veterinarians without much expertise in avian medicine, giving NaCl (5% of the body weight) subcutaneously in the shoulder or inguinal region is a very good start.
Fixation can be accomplished by external coaptation, external skeleton fixation, internal fixation or combinations. External coaptation only gives acceptable results in some fractures of the legs more distally than the knee and single fractures of the antebrachium. External skeleton fixation is a very good treatment option for most fractures of the extremities. Internal fixation can be accomplished by intramedullary pins; Single intramedullary pins don’t provide rotational stability and should not be used as a sole treatment! Intramedullary pins can for example be combined with ESF. Because of the poor screw-holding capacities of the thin and brittle cortices and the size and price of most implants, plate ostheosynthesis is not frequently used in birds.
As in mammals, orthopedic procedures are painful and should only be done under full anesthesia with optimal analgesia. Isoflurane does not have the most potent analgesic properties, so the use of this gas as a sole anaesthetic in orthopedic surgery is not very friendly. Personally, in most avian patients I prefer the use of butorphanol and meloxicam as premedication and, depending on the size, age and health of the patient, isoflurane and/or medetomidin/ketamin for induction and maintenance of the anesthesia and additional analgesia. Of course, other anesthetic protocols are optional or even preferable in some cases.
Avian bones heal faster than mammalian bones, on condition that the fractures have been fixated correctly and no complication (infection for example) occur. Bandages of the wings, if used at all, should be removed a soon as possible to prevent permanent soft tissue contraction and restricted joint motion.
Rob van Zon