Broken Legs In Song Birds – And How I Repair Them
Ron Hines DVM PhD
Birds with a broken leg like this mockingbird will often use the wing on the same side as a crutch to help support and steady themselves
There are innumerable ways wild birds suffer bone fractures. No two are alike. The repair of fractures in adult birds is considerably more challenging that the simple method I describe in this article for baby birds. The skeletons of adult birds are already fully calcified. So their bones are brittle. Fear, stress and struggle in adult wild things is always an issue to deal with.
Adult avian wings and leg bones, being hollow, break with razor sharp edges that quickly slice through ligaments, nerves and muscle as the perplexed creature struggles to walk or fly. When portions of the bone protrude through the skin, they are always contaminated. I must removed those portions and I must devise complex implants to bridge the missing gaps. Many of the larger birds that Texas game wardens bring me have been shot and their wounds are full of small devitalized bone fragments. I repair all of them when I can. But many have no future hope free in the wild. I am always looking for good homes for these creatures. Let me know if you might accept one.
Which Injured Birds Offer The Most Hope?
Immature birds, like this mockingbird with a simple leg fracture have considerably more hope for a successful release. “Simple” fractures do not mean that they are simple to repair. Veterinarians and physicians classify traumatic bone fractures as “simple” transverse (only one fracture line), “compound” (pieces protruding through the skin), “comminuted” (more than two pieces or fragments), greenstick (incomplete fractures) as well as by their angle (transverse, oblique and spiral). Because the bones of these baby birds are still quite soft, they tend to have simple fractures or greenstick incomplete fractures that heal rapidly at whatever angle the creature rests its limb. The secret is to keep the bone sections aligned properly during the healing process. Some of these birds get to me after the fracture has healed at bizarre angles. Those I have to re-fracture, position them properly one way or the other and allow them to heal correctly. Sometimes it takes me up to four surgeries because the bones and joints have distorted to deal with the force of gravity and because surrounding muscles and ligaments have shortened in length. Domestic birds raised on slick surfaces face similar issues. You can read about that problem here.
I hope the photos below speak for themselves. If they don’t you can always send me an email. I use stainless steel rods placed within the hollow of the bone when I am working on large birds. But to stabilize the fractures of these diminutive songbirds with intramedulary bone pins usually requires the pin(s) to pass through a joint which causes permanent damage. I occasionally construct a tiny Kirschner apparatus from 25 – 22 gauge hypodermic needles and a piece of methyl methacrylate -filled PVC tube borrowed from an IV set or some other disposable medical tubing. But I reserve that for larger wading birds such as herons and flamingos. These devices are too cumbersome to use successfully on these small birds.
Due to the fact that the bones of birds are hollow and brittle, none of these complex techniques work as well as we would like. You can read about ongoing trials of complex bone fixation techniques here.
Baby birds grow very rapidly. At that young age they also have a remarkable ability to surmount (heal) fractures if you can just keep the bone portions in proper alignment. That never happens in the wild. It is always a good idea to purchase a precious metal scale like the one in photograph 2. These scales are not expensive on Amazon or Ebay. The mockingbird in the top photo weighed 20.7 grams when I applied its splint. I weighed the chamomile tea box before I put him in it (14.72gms) and again with him in it (35.42gm). Eight days later the mocker weighed 38.2 grams.
Photo 3 shows the location of the fracture. The break was through the lower section of its right tibia. That is your and my “shin bone”. The skeletons of birds are very different from ours in the way they evolved. It was very fortunate that no sharp portions of the fracture penetrated through the skin. Birds at this tender age have less calcium in their bones than adults. So they are much less likely to end up with fractured fragments that cut through surrounding tissue (ligaments, nerves and blood vessels) as the bird struggles. Because the bones of birds are hollow to save weight, their bones are harder (more calcium) than those of mammals and more likely to end up with knife-like edges when they break in an adult bird.
Photo 4 is a second photo of the fracture on the day it arrived. I drew a yellow arrow where the break had occurred. Because of that fracture, the leg just dangles uselessly. The accident that caused it must have occurred a day or two earlier because you can see that the mockingbird had already abraded its left hock joint and the toes of the other leg are already beginning to grow out of alignment (crooked) to compensate for the new way the bird supported itself on one leg and a wing.
I didn’t use the pliers in photo 5 or 6 to form the wire loop around a syringe. It is just something I used to support things while I photographed. You can just see the tip of the bull-nosed surgical needle holders that work much better than pliers for me. I am sure the needle holders have a specific medical name. But I am not going to take the time to find out what it is. If you want a full photo, email me. However, simple household pliers (or better yet – needle nose pliers) might work for you. Team up with a hospital surgical instrument repair person when you need surgical instruments. When hospital instruments are discolored or have other minor defects that do not preclude their use, they are usually discarded as not being worth the cost of repair or as presenting liability issues.
The red arrow in photo 7 shows the path that the birds leg will pass through when the splint is applied. It is called a modified Thomas splint. The yellow arrow shows the point where the fracture will be once the splint is applied. The blue arrow shows the point that will be just under and supporting the “palm” of the foot. You can see a bit more of the bull-nosed needle holders in the far upper right. The household pliers were just placed there to support the splint for the photo.
Regarding photo 8, the Tegaderm™ adhesive film is optional. These days I work alone. 3M Tegaderm™ and repurposed products such as Medline Suresite™ are extremely sticky, floppy and quite hard to work with without the extra sets of vet tech hands I once had to assist me. But these products stick to the skin of birds considerably better than the hospital-grade bandage tape that I apply over it for extra support and protection. Some tiny birds require only the stiffness of tape to heal satisfactory. As the bird’s skin surface sheds (desquamates), Tegaderm™ and Suresite™ comes loose by themselves at about the time I want them to. I do this orthopedic work using watchmaker tools, ophthalmic instruments and magnification so as not to injure these little creatures. They are so so fragile.
In photo 9, eight days have now passed since the Thomas splint was first applied. You can see the increased blood supply at the fracture site as the upper and lower portions of the bone attempt to unite and become stable. I check these birds every day – often removing the previous tape to be sure blood is flowing adequately through the leg and that the positioning is just right. Improper tape pressure quickly causes skin ulcers (“bed sores”) or worse. As an avian bone heals, it heals primarily on its outer surface – not within the bone’s hollow center. The new bone (callus) begins as a blood clot. With time, cells that produce cartilage (chondrocytes) arrive to stiffen the area. Since the original clot was large, a firm lump begins to form. You can see that in the photo. With time, cells called osteoblasts replace the cartilage with bone. As more time passes, the lump shrinks and remodels – hopefully to not be much larger than is required to support the bird’s weight. A problem I deal with more in broken wings than broken legs is when important ligaments that allow wing motion become trapped in the bone callus. It is always a judgement call as to when stabilization devices cause more harm than good.
Photo 10 is just another photo I took on the 8th day after the splint was applied. Gently putting fingers above and below the fracture site and gently testing its rigidity, I can see that it is no longer required. I placed the splint it on my little finger so you could see it better. It was a chore carefully picking the remainder of the Tegaderm™ off with ophthalmic forceps and tweezers but the mocker put up with me doing it. I never give anesthetics when I don’t have to. In big birds it is necessary. In those cases I give small doses of ketamine intramuscularly. On rare occasions, I will still administer isofluorane gas to bird for general anesthesia. Purists might fault me for not using iso more frequently. However placing the required endotracheal tube to deliver gas to these small birds is not without risk, the smell of iso is horrible, makes me giddy and is probably not healthy for us either. It would be quite foolish for a single individual like me to attempt these delicate operations and monitor the depth of anesthesia simultaneously. Ketamine has never let me down.
Photo 11 was taken on day 10. The mockingbird is already using its injured foot well. However, he has still not regained full use of his toes. That has to do with the remodeling bone callus I mentioned to you earlier. This would be a good time for physical therapy. However mockingbirds resent being restrained. An alternative is to begin provide available perches that are smaller in diameter. I always begin by give leg-injured birds large diameter perch branches. Besides offering them more foot stability, large branches help keep toenails from overgrowing during extended periods of recovery. Some injured birds are with me 6 month to a year before they are finally ready to be released.
I took photo 12 on the 13th day after the bird arrived. You can see that it has fully regained the use of the toes on its injured leg. Today I put the mockingbird in a large outdoor flight to see how it gets on with the resident mockingbirds. If they accept it, I’ll just leave the cage door open so it can come back for food when it wants to. We still have two young-of-the-year screech owls coming back at sundown for a handout of the same cat food and a white-wing dove we raised last summer occasionally drops by to say hello and eat milo. You can read about how to successfully raise white-winged doves here.
I have been known to dab a tiny drop of red nail polish on the end of a tail feather to recognize a bird I had released. Of course they will loose that feather on their next molt. Don’t leg band birds. It is a cruel and needless procedure that provides little to no useful information that could not have been gathered through other more humane means. A local biologist traps and bands birds down here. I frequently get his birds in with bands placed too tightly on their legs. Raptors just starve to death with tight bands. Others loose their leg. Too loose an open band will snag on objects. I remove all bands when given the opportunity.
The granjeno and brazil berries you see in the dish in my photos are what these birds normally eat this time of year. In another few weeks when there are no more berries anaqua fruit will be plentiful. The food in the jar cap is Purina Friskies Shreds™. They prefer the Chicken and Gravy entree to Purina’s other flavors ) I planted these berry bearing shrubs years ago for the birds. Several mockers reliably harvest them every year. Mockingbirds are intensely territorial and each guards its own stand of bushes. The photos taken behind my home are of granjeno, brazil and anaqua in that order: