The Novel Use of Hinged Braces as External Support Devices for Soft Tissue Joint Injuries in Long-Legged Birds
1Patuxent Wildlife Research Center, Laurel, MD, USA; 2Baltimore Zoo, Druid Hill Park, Baltimore, MD, USA; 3National Aviary, Allegheny Commons West, Pittsburgh, PA, USA; 4Present address: HSUS, Washington, D.C., USA
Management of soft tissue joint injuries in long-legged birds is often frustrating and unrewarding due, in part, to the lack of appropriate external stabilization devices that allow for the continued use of both legs during the healing process. Birds that are immobilized for a period of time often become fractious, intolerant of the restraint, and generally depressed. Skeletal muscle atrophy complicates the medical management of these birds, often resulting in an unsuccessful recovery, unless a rigorous physical therapy program is instituted.1 In an attempt to ameliorate these complications, the authors have adapted hinged brace assemblies as novel external support devices for soft tissue injuries to tarsometatarsal (hock) joints in several species of long-legged birds.
A 2-yr-old, endangered Mississippi sandhill crane (Grus canadensis pulla) presented with an acute grade 3 lameness of the right leg with swelling of the medial hock. Radiographs demonstrated soft tissue swelling without evidence of fractures or luxations. There was moderate mediolateral laxity of the joint on palpation suggesting a medial collateral ligament rupture, however. The joint was initially stabilized with a support bandage of cast padding and elastic wrap (Vet Wrap®) to allow the bird restricted function of its leg. Mild hock swelling, medial joint laxity, and a grade 2 lameness persisted after 2 wk. Sequential radiographs demonstrated no significant change in the initial findings.
The crane was anesthetized with isoflurane and a Phoenix® adjustable hinged elbow brace (Smith & Nephew) was fitted as an external support of the right hock. The brace was constructed of a lightweight aluminum alloy with a ball-bearing hinge to allow friction-free movement within a normal range of motion (ROM). Adjustable static bracing was possible if metal stops were inserted in the hinge. This restricted movement feature was not necessary in this case. Microfoam® tape was applied as padding to the leg proximal and distal to the affected joint to protect the skin surface from friction rubbing. The brace was properly aligned along the medial and lateral aspects of the hock so that the center of the hinge matched the point of flexion and extension of the joint. Stainless steel surgical wire was looped through each end of the brace armature and subsequently interwoven between the layers of adhesive tape that secured the brace to the Microfoam® tape on the leg. Upon recovery from anesthesia, the crane began walking immediately without appreciable lameness. There was normal ROM with flexion and extension of the hock during walking, sitting, and rising. The crane tolerated the presence of the support brace for 4 wk. Once the brace was removed, a soft bandage was placed on the right hock to provide minimal support for one additional week. At that time, the crane had regained normal ambulatory function and it was returned to its field pen.
This type of brace apparatus has been used successfully for similar injuries in several species of cranes, flamingos, and storks. A substitute brace of similar design, but of lesser stability, was constructed from the hinged ribs of an umbrella frame. Padding the arms of the umbrella ribs in an adhesive tape wrap, and securing the apparatus medially and/or laterally to the leg, significantly increased the stability of the joint. This device was used successfully on an adult green magpie (Sissa chinensis) which sustained a ruptured medial collateral ligament with complete joint instability. The brace was well tolerated for 4 wk with the subsequent achievement of good joint stability and ROM after removal.
The novel adaptation of hinged devices for use as external support braces for soft tissue injuries of joints in birds has been remarkably successful. A dynamic hinged brace designed for human elbow injuries was fitted to the leg of a Mississippi sandhill crane. It permitted normal ambulation with full ROM of the affected hock, and afforded mediolateral stability to the joint until the soft tissue injury resolved. A similar hinged brace constructed from umbrella ribs provided external support to the luxated hock of a green magpie with resultant return of joint function. These birds were completely tolerant of the hinged brace assemblies without interruption of their normal behavioral and motoring activities.
1. Klein P, Thompson D. 1997. Long bone fracture management in a sandhill crane: a case report. Proc North Am Crane Workshop. Biloxi, MS. In press.