Hawk with a Fractured Wing

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A red-tailed hawk was found on the runway at Long Beach airport and brought into our Wildlife Program with a broken wing. Our ultimate goal is to fix the wing and release the hawk back into the wild. There is no guarantee that will happen, but we are willing to give it a try.

Graphic surgical photos later in this page. 

Our Wildlife Program admission form gives you more details when it was brought in by Long Beach Animal Control on September 29th, 2018

It had a band to help us trace its origin (number 1967) and learn more about it

Jonathan went on the U.S.G.S. (U.S. Geological Survey) at the Patuxent Wildlife Research Center web site and put in the band number so they know this birds disposition

This is some of the information he provided

Jonathan is a natural with wildlife, and his care before and after surgery is a big reason for the successful outcome of this case

This is the bird just after its admission exam and as it was being brought to our wildlife room upstairs

Birds of prey are easily stressed, so after the initial exam and treatment we let it rest in a quiet area in the wildlife room

Radiographs revealed a mid-shaft oblique fracture of the right humerus. This fracture requires surgery if there is any chance this bird will fly again.  Do you see the 3 pellets also? Removing them causes more trauma than it is worth, so we rarely remove them. The one concern we have with this approach is if the pellets are made from lead, which is usually not the case.

It is common for people to wonder how this bird broke its wing. Did the pellets cause it to fall and break its wing, or were they there from a previous time when someone shot it. Maybe all of the pellets were not from the same time period. We can only speculate, but in this situation, the cause has only indirect bearing on how we will be treating this bird.

Raw bone ends are very painful. We wrapped the wing in a soft and secure bandage to minimize pain and stabilize the bone to prevent further injury.

We put it on pain and anti-inflammatory medication, along with supportive care like assist feeding and fluids, to make it stronger in anticipation of surgery in a few days. When we felt it was stable and ready for anesthesia we performed orthopedic surgery to repair the fracture using a pin and wires. We did not take out the pellets.

Injections of medication can traumatize the breast muscle when given daily, so much of the medication is given orally 

In most mammals (dogs, cats, humanoids) a plate and screws give the best stability for healing of the humerus. Birds have light bones so their weight does not interfere with their ability to fly. We prefer not to use plates and screws that are heavier than a pin and wires due to this weight issue with bird bones and flight.

In addition, after the bone has healed, plates and screws need to be removed due to their weight and interference with flight. This requires another anesthetic procedure and additional trauma to the area. The stainless steel pin is easily removed without anesthesia, and the stainless steel wires that are put in to help stabilize the fracture are light and can be kept in place.

Some medical terminology to help you understand the surgery we will be performing:

  1. The segment of broken humerus towards the shoulder is called the proximal segment
  2. The segment of broken humerus towards the elbow is called the distal segment
  3. The inner cavity of the bone, which contains bone marrow that produces red blood cells, is called the medullary canal. In some locations on the bird, the canal is hollow for weight reduction for flight.
  4. The outer layer of the bone, where the strength of the bone resides, is called the cortex.
  5. The cortex of a fractured bone that is healing properly has an exuberance of calcium and protein matrix deposited on it that can be seen on a radiograph (X-ray).
  6. This exuberance is called a callus, and the amount that is laid down in a normally healing fractured bone cortex varies. It can be seen on a radiograph as a deposit on the cortex over the fracture site.
  7. If you want to get technical: callus comes from periosteal and endosteal osteoblasts aiding osteoclasts in creeping substitution remodeling.
  8. When we see this callus on a post operative radiograph we know that healing is progressing normally. If it is not present, it could be that the bone needs more time, there is an infection, there is loss of blood supply to the cortex,  a bone plate has been put on improperly, or there is motion at the fracture site. Each one of these causes requires a different treatment to correct.
  9. When the bone does not heal properly it is called a non-union, a potentially serious consequence that might require amputation of the affected limb.
  10. A stainless steel pin, called an intramedullary (IM) pin will be used. Intramedullary means it will go right down the shaft of the bone.
  11. The wires we use to help stabilize the fracture are called cerclage wires
  12. The anesthetic breathing tube that goes down the trachea (windpipe) is called an endotracheal tube. It is abbreviated as ET (this is not the same ET as the movie!). This is safer for the bird and gives us more control of anesthesia.
  13. Even though it is not apparent from the surgery photos that follow, a special effort is made to prevent hypothermia (dangerously low body temperature) during the surgery by administering supplemental heat. We do this with warm internal fluids, warm water blankets, and additional heat in the form of warm water fluid bags around the bird. You cannot see them during the procedure because the drape covers them.

Brianna our anesthetist bringing our patient into our surgical suite on the day of surgery after its morning treatment of pain medication and internal fluids

We initiate anesthesia with a mask that supplies 100% oxygen and anesthetic gas

When our patient is relaxed we place the ET into the windpipe. In this photo Dr. P is opening the mouth and holding down the tongue with his right index finger to aid Brianna in placing the ET tube. 

Proper placement of the tube is crucial, and it is easy to put in down the wrong pipe (the esophagus).  Dr. P is confirming the proper placement of the tube prior to connecting the anesthesia machine

Our bird is now under complete anesthesia, and our team of Dr. Kennedy, Brianna, and Alex, is readying it for surgery

You can see the bruising to the area after the feathers have been removed and the skin has been prepped

After checking anesthesia and draping our patient, Dr. Kennedy and Dr. Wood begin the procedure, while Dr. P photographs and gives advice

The anesthetic level of our patient is constantly monitored during this long procedure. Our surgeons are careful not to lean on the bird because this can make respiration impossible with obvious catastrophic consequences.

To get oriented, the shoulder is at the top of this picture, the elbow is at the bottom. The skin incision is made directly over the fracture site, taking care not to damage any nerves or blood vessels, as the muscles are gently dissected to get to the broken bone. What seems so apparent on a radiograph is not so apparent when you go in surgically, and there is blood, swelling, muscles, nerves, and tendons all around the bone. This also gives you an idea of how hard it can be to find the pellets. 

The forceps is holding the proximal segment of the bone, that part that connects to the shoulder. After several minutes of careful dissection the fracture segments are exposed. Contraction of the strong muscles in this area has caused significant override of the bone ends. Aligning these ends takes time and gentle manipulation to get them back into normal position in order to be able to place the pin.

After picking the correct size, our surgeon slowly inserts a stainless steel IM pin into the proximal segment of the humerus

It is slowly advanced towards the shoulder with the help of an instrument called a pin chuck and lots of rotational movement. Bird bones are relatively fragile compared to mammals, and we need to be very careful not to fracture the cortex of the bone along the way. You cannot see the pin as it goes down the shaft, it is all done by feel. Picking the correct size pin is important because of these fragile bones. If the pin is too large it can cause another fracture, but if it is too small it does not give enough stability for healing. 

It comes out through the skin near the shoulder joint, but does not interfere with shoulder movement

The pin chuck is taken off its original position on the pin, and repositioned so that the pin can now be pushed distally back to the fracture site

It is pushed just to the point where it is sticking out of the fractured end of the proximal bone segment

The distal segment of the humerus is lined up just over the pin, and the pin is slowly pushed forward into the the shaft of  this distal segment, aiding in alignment of the fractured ends. Getting proper alignment of the proximal and distal segments of the bone is one of the more delicate parts of the procedure, and takes two sets of hands. We need to go by feel again as we push it down to the most distal end of the humerus without going through that cortex. Measuring the IM pin length ahead of time helps.

The pin does not give enough stability by itself. Cerclage wires are needed to add proper stability, and in this fracture 3 were used. This is a large bird that puts tremendous pressure on this wing when it flies, and we need to make sure there is no movement at the fracture site during healing as the bird exercises its breast muscle to get strength back. If not, we might get a non-union and the wing might need to be amputated.

When our surgeons are convinced the IM pin is properly placed, and the cerclage wires are holding well, the muscles over the bone are sutured to bring them back into normal position, taking care not to injure any other structures like nerves. The skin is sutured closed with a non-reactive suture material that will be removed in 10-14 days. The drape has been removed for you to visualize the incision line.

A post-operative radiograph is quickly taken while our patient is still anesthetized

There are 2 things to note on this radiograph:

1. Lower Circle- The pin has been inserted down the shaft of the humerus as far as it can go without going through the cortex of the bone distally. The cortex of the bone is thin as can be seen on this radiograph, and if the pin is pushed too far distally iy can easily go through the cortex. This radiograph shows perfect placement by our surgeons.

2. Upper Circle– The cortex of the bone under the cerclage wires shows good alignment 

The end of the pin at the shoulder is sticking out too far for normal wing movement, and now needs to be cut shorter. This is not done until the post-operative radiograph confirms the pin is seated properly in the distal cortex of the humerus. If not, it is adjusted now while the hawk is still under anesthesia. Enough pin needs to be left for the chuck to grasp the pin months later for removal.

The pin is made of very strong stainless steel, and it takes large bolt cutters to cut off the extra length

This is the proper length for this pin now that it has been cut, allowing for proper movement of the shoulder, and giving enough purchase for removal with the pin chuck months later

Bonewax is used to help protect the skin in the area from trauma due to the cut end rubbing under the wing. This can cause ulceration and infection, the last thing we want festering under a bandaged wing.

It is molded over the cut end of the pin

The skin and feathers are dried before the bandage is applied. Moisture under the wing wrap can predispose the skin to a fungal infection 

A piece of sterile gauze is placed over the bone wax after the skin and feathers are completely dry

The post-operative bandage is now applied using gauze and vet wrap 

The final appearance of the bandage around the chest and wing. It needs to be tight enough to immobilize the humerus, but not so tight as to impede respiration. This is important in birds, since they do not have a diaphragm, and need to move their chest in and out more than mammals do. This was alluded to earlier when we talked about the surgeons not inadvertently leaning on their patient while they are concentrating on their surgery. 

Our hawk is now taken completely off anesthesia and given 100% oxygen as it awakens. It is wrapped in a towel and held this way until fully awake to prevent thrashing and damage to the fractured humerus. 

The skin incision is checked a few days later. This one is healing fine, so there is no need to change our post-operative protocol. The bandage was reapplied and the bird was prepared for release to our rehabilitators. 

This is just the beginning, because now this hawk needs rest, food, rehabilitation, and post-operative radiographs and exams over the next several months if we want this surgery to be a success.

It is time for this bird to go to the expert rehabilitators at South Bay Wildlife Rescue for long-term care and to build strength back into the wing while the bone is healing. If it wasn’t for the expertise and dedication of Ann Lynch and all of her volunteers who do so much behind-the-scenes work, it would not have been worth doing the surgery.

The handoff from Dr. Wood to Christina from South Bay 

At first is was put into a special cage, and when the IM pin was removed later, it was put into a flight cage to start getting its wing and breast muscle strength back

The hawk adapted well to the flight cage, and was soon exercising its injured wing

An exam and  follow up radiograph one month later revealed good callus formation at the fracture site and intact cerclage wires. Also note that the tip of the pin has not moved very much, which means we picked the proper diameter pin to put into the medullary canal of this humerus. 

 It was brought back to us one month later for radiographic and physical assessment on whether the pin should be removed. It was eating well and maintaining its weight, so we were hopeful for a release back into nature.

An exam and radiograph one month later said we were good-to-go for pin removal

The chuck was put on and the pin carefully removed

Our pin, feathers and all, after removal

We wish Dr. Wood would show a little more enthusiasm for her work!

The appearance of the humerus after the pin was removed. The cerclage wires are intact and the fracture site has healed with healthy cortical bone. 

An exam after pin removal confirmed the fractured humerus had healed properly

It was 2 months from the time the bird was presented to us on Oct 13th, 2018, until the pin was removed. After pin removal the hawk was kept in the flight cage under Ann and her teams close observation to determine when it could be released back into the wild. Even though the wing drooped, the hawk seemed to progress. Unfortunately, after several months, Ann determined that the bird was not strong enough to fly and hunt on its own successfully. She sent Dr. P an email saying she would keep it as a teaching bird.

A month later Ann changed her mind and said the bird is releasable. U.S.D.A. release protocol states to release the bird at least 150 miles away from where it was found if that was at an airport. Otherwise, unless a poisoning or shooting is involved, it is put back where it was found. Since this hawk was found at Long Beach airport we needed a new release location 150 miles away.

Based on prior experience it was determined that Lone Pine, CA along Highway 395 was a good location. There is a golf course there with lots of tree and cover for prey, and other birds had been released there successfully. Soon after determining it was releasable, Dr. P and his assistant Georgina Strange loaded up the bird at Ann’s house and drove right to Lone Pine and the golf course.

The release location was ideal, with many trees for hiding and perching, lots of underbrush for prey, and mountains in the area for a varied vantage point

It was over a 3 hour car ride to Lone Pine, and Dr. P was nervous about how the bird did when he arrived at the golf course. Was it alive, was it in shock, would it fly away, or would it just sit there? The release went well, and the hawk exploded out of the carrier when Dr. P opened it. After 7 months of treatment and confinement it was free!

It flew towards another adult red-tailed hawk that had a younger bird with it (you can see the younger bird on the ground to the right of the 2 larger birds). After a brief interaction it flew off and we called it a day.

As you can see it takes a major team effort for a successful release of a bird of prey back into the wild. A special thanks to Dr. Kennedy, Dr. Wood, Brianna, and Alex, for their expertise in anesthetizing and repairing this bird’s fracture. This thanks includes all the staff that took care of this bird before and after surgery. Kudos to everyone at Long Beach Animal Hospital and South Bay  Wildlife Rescue!

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