How to Perform an Orthopedic Examination in the Bird

Visual examination

Injuries of the thoracic limb may present as a wing droop or an inability to fly (Fig 1). Injuries of the pelvic limb may present as lameness, unequal weight bearing, and/or an uneven grip.

ABE wing droop Leighty

Figure 1. The prominent wing droop in this bald eagle (Haliaeetus leucocephalus) indicates orthopedic or soft tissue injury involving the left wing. Photo credit: Michelle Leighty. Click image to enlarge.

Anatomy

Know–or review–avian anatomy before beginning the physical examination (Fig 2-Fig 4). The bird’s appendicular skeleton is an example of fusion and simplification. The propatagium is an important ligament that runs from the shoulder to carpus. This ligament may be palpated within the leading edge of the wing web or patagium (Fig 5).

Pelvic limb of the bird

Figure 2. Pelvic limb of the bird. Drawing by C. Pollock. Click image to enlarge.

Thoracic limb of the bird

Figure 3. Thoracic limb of the bird. Drawing by C. Pollock. Click image to enlarge.

Four digits named from medial to lateral.

Figure 4. There are four digits that are named from medial to lateral .Click inage to enlarge

Box 1. The avian appendicular skeleton is an example of fusion and simplification
Manus Major and minor digits
Metacarpus Major and minor metacarpal bones that are fused proximally and distally..
Alula A carpal bone that extends off of metacarpal bone III. The alular carpal bone as well as the alular feather are important in maneuvering.
Antebrachium The ulna is the larger bone.
Humerus Curvature of the humerus varies greatly among bid species.
Pectoral girdle The bones of the pectoral girdle are the clavicle, coracoid, and scapula.
Femur A short, stout bone. The avian hip joint is relatively shallow and abducts only a very small amount.
Patella The presence of a patella will vary with the species.FibulaLateral to the tibiotarsus. This bone is fused proximally with the tibiotarsus, and its presence will vary with the species.
Tibiotarsus The avian hock joint is blissfully simple when compared to mammals. The tibiotarsus develops embryologically from a fusion of the tibia and the proximal row of tarsal bones.
Tarsometatarsus This bone develops embryologically from a fusion of the metatarsal bone and the distal row of the tarsus.
Digits Digit #1 or the hallux is directed caudally. Digits 2, 3, and 4 are directed cranially with digit # 2 located medially and digit #3 in the most lateral position.
Pectorals and patagium

Figure 5 . Wing web or patagium with the propatagialis ligament running in the leading edge. Click image to enlarge.

Restraint

Although the normal, healthy bird may be restrained manually, injured birds are at great risk for exacerbation of their injuries (Fig 6). Consider general anesthesia when orthopedic injury is suspected. Careful palpation may be performed at the same time as survey radiographs are performed.

Metacarpal fracture

Figure 6 . An injury like the metacarpal fracture shown here can be made worse during handling and restraint unless proper precautions are taken. Click image to enlarge.

Physical examination of the wing

To carefully examine the wing, first determine that the wing is capable of full extension (Fig 7). Grasp the wing at the carpus with the fingers extended over the wing web or patagium while supporting the elbow (Fig 8).

Grasping carpus of a kestrel

Figure 7 . Grasping carpus of a kestrel (Falco sparverius). Photo by E. Ramsay. Click image to enlarge.

Examining the wing

Figure 8 . While examining the wing, grasp the limb at the carpus with the fingers while supporting the elbow. Click image to enlarge.

Palpate the wing from digits to shoulder taking each joint through passive range of motion. Also be sure to run a finger along the wing web. Any disruption of the wing web disrupts the avian airfoil and can therefore remove the ability to achieve flight. Also carefully palpate the axillae for any swellings.

Never get in a tug of war over the wing. If the bird struggles strongly, fold the wing back against the body to prevent injury.

 

Physical examination of the pelvic limb

Note the degree of strength in the bird’s grip. Check the plantar surface of each foot for redness, swelling, or ulcerative lesions. Palpate each leg starting at the toes and moving up the limb, taking each joint through a passive range of motion. Never hold the leg just by a toe as this can cause injury. Handler or examiner should always support the limb by grasping the tarsometatarsus or by resting a hand around the stifle.

 

Further reading

Brown RE, Baumel JJ. Anatomy of the propatagium: The great horned owl (Bubo virginianus). Journal of Morphology 219(2):205-224, 1994.

King AS, McClelland J. Birds: Their Structure and Function, 2nd ed. WB Saunders Company; 1983.

Orosz SE. Anatomy of the musculoskeletal system. In: Altman RB, Clubb SL, Dorrestein GM, Quesenberry K (eds). Avian Medicine and Surgery. Philadelphia: WB Saunders Company; 1997. Pp. 517-522.

Orosz SE, Ensley PK, Haynes CJ. Avian Surgical Anatomy. WB Saunders Company; 1992.

Proctor NS, Lynch PJ. Manual of Ornithology: Avian Structure and Function Yale University Press; 1998.