News Release

 
Contact: Sondra Katzen, Public Relations, 708.903.2071, sondra.katzen@czs.org
 
January 27, 2021
 
FOR IMMEDIATE RELEASE
 
   

Brookfield, Ill. — Today, an endangered Amur tiger suffering from an arthritic hip underwent a successful total hip replacement surgery at Brookfield Zoo with a custom-designed, patient-specific implant. This is believed to be the first time such a procedure was attempted on a tiger in North America. During the surgery, which took place at the zoo’s state-of-the-art Animal Hospital, 10½ -year-old Malena received a custom-made implant that was designed and manufactured to fit her perfectly.

Like humans, animals routinely develop degenerative changes in their joints as they age that can lead to the development of arthritis. When Malena arrived at Brookfield Zoo from another zoo in June 2020, she had already been diagnosed with hip arthritis and had been receiving pain relief medications to keep her comfortable. As part of Malena’s incoming medical examination, Chicago Zoological Society (CZS) veterinarians included a CT scan to fully characterize the status of her hips. (Brookfield Zoo is one of only a few zoos in the world to have a CT scanner on-site.)

The resulting diagnostic images revealed extensive arthritic changes in her left coxofemoral (hip) joint consisting of degenerative changes, subluxation (partial dislocation), bony remodeling, and joint effusion (swelling). Collectively, these changes restrict her range of motion and use of the leg, in addition to causing her pain and stiffness when walking.

The zoo's veterinary team consulted with Dr. James Cook, DVM, Ph.D., the Allen Distinguished Chair in Orthopaedic Surgery, director of the Mizzou BioJoint Center at the University of Missouri, and a veterinary
surgeon with expertise in joint disease, who has assisted on several other orthopedic cases at Brookfield Zoo. Given the severity of the lesions in her left hip and Malena’s age, they felt that a full joint replacement, or a total hip arthroplasty (THA), was the best option to relieve arthritis-associated pain and provide a return to normal joint function. THA is a procedure in which surgeons replace worn-out and damaged sections of the hip bone (femoral head) and pelvis (acetabulum) to create an artificial joint using implants. Although it is routinely performed on people, the procedure is less common in veterinary medicine, particularly in non-domestic species. Standard THA implants often do not fit the anatomy of different species well, requiring customization—especially in an Amur tiger like Malena. Previous THA attempts with non-custom implant designs in a snow leopard, a cheetah, and a tiger in Germany have yielded mixed success.

 “Although geriatric, Malena could still have many years of life ahead of her, so our team was focused on finding a solution that could keep her active and comfortable,” said Dr. Mike Adkesson, vice president of clinical medicine for the Chicago Zoological Society, which manages Brookfield Zoo.

After deciding that a custom-designed, patient-specific THA offered Malena the best potential outcome, Dr. Cook reached out to Arthrex, a global leader in minimally invasive orthopedic technology headquartered in Naples, Florida. Using data from Malena’s CT scan, the company designed, manufactured, and donated a custom-made implant that is specifically designed for Malena’s joint.

 “Arthrex is pleased to have collaborated closely with the veterinary team at Brookfield Zoo and with Dr. Cook to develop this implant for Malena. The level of care and support she has received is a testament to the dedication of her caregivers. Over the last decade, Arthrex has applied its expertise in human orthopedics and orthobiologics to develop cutting edge technologies for the treatment of veterinary orthopedic injuries and disease and we’re honored to utilize this experience to help Malena return to activity quicker and with less pain,” said David Shepard, senior director of vet systems and orthobiologics for Arthrex.

The procedure and Malena’s case are the result of comparative translational medicine, where medical professionals from different disciplines, backgrounds, and expertise work together to improve patient outcomes by putting the science behind the surgery—for four-leggers and two-leggers alike. Many of the same types of biomedical engineering and technology practices used on humans can benefit animals and vice versa.

“It’s very rewarding to be able to use the latest in human medical technology to give back to an animal in need, especially when endangered like Malena,” said Dr. Cook. “The fact that this technology will also directly advance hip surgery for animals and people is just an awesome example of the One Health-One Medicine concept that the Brookfield Zoo and Mizzou teams love to see put into practice.”

To prepare for the surgery, which took just over six hours, the veterinary surgical team was able to refine and practice the procedure extensively using computer simulations, as well as using 3D-printed models.
“This implant will restore Malena’s normal hip movement and alleviate her discomfort. It will allow her the ability to navigate around her outdoor habitat without difficulty and lead a normal life for a tiger,” said Dr. Adkesson. “We are extremely grateful to Dr. Cook and his team, as well as to the engineering and research staff at Arthrex for manufacturing and donating the implant, which will greatly improve Malena’s quality of life.”

Amur tigers (formerly called Siberian tigers) are the largest cats in the world, with some as large as 11-feet long. This subspecies of tiger is adapted to live in colder climates and mountain forests, predominantly in the Russian Far East. There are only an estimated 500 Amur tigers left in the wild. Brookfield Zoo is fortunate to house two Amur tigers. In cooperation with other institutions accredited by the Association of Zoos and Aquariums, the Chicago Zoological Society participates in the Tiger Species Survival Plan® (SSP), a conservation and population management program, and the Tiger Conservation Campaign. This campaign raises awareness about the plight of tigers and raises funds for anti-poaching and other programs to help save tigers and their habitat.

 

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Photo Captions

Malena  Amur Tiger-1 and Malena Amur Tiger-2: Malena, a 10½-year-old Amur tiger at Brookfield Zoo, underwent successful hip replacement surgery with a custom-designed, patient-specific implant on January 27. This is believed to be the first time such a procedure was attempted on a tiger in North America. (Cathy Bazzoni/Chicago Zoological Society)
 
1520: Malena, a 10½ -year-old Amur tiger at Brookfield Zoo, underwent successful total hip replacement surgery. This is believed to be the first time such a procedure was attempted on a tiger in North America. During the surgery, which took place at the zoo’s state-of-the-art Animal Hospital, the big cat received a custom-made implant that was designed and manufactured to fit her perfectly. (Jim Schulz/Chicago Zoological Society)
 
1854: Malena, a 10½ -year-old Amur tiger at Brookfield Zoo, is prepped for total hip replacement surgery at Brookfield Zoo’s state-of-the-art Animal Hospital. This is believed to be the first time such a procedure was attempted on a tiger in North America. During the surgery, which took place at the zoo’s state-of-the-art Animal Hospital, the big cat received a custom-made implant that was designed and manufactured to fit her perfectly. (Jim Schulz/Chicago Zoological Society)
 
2701: Dr. James Cook, DVM, Ph.D., the Allen Distinguished Chair in Orthopaedic Surgery, director of the Mizzou BioJoint Center at the University of Missouri, and a veterinary surgeon with expertise in joint disease, led a team during a hip replacement surgery on an Amur tiger at Brookfield Zoo’s Animal Hospital. (Jim Schulz/Chicago Zoological Society)
 

 

About the Chicago Zoological Society
The mission of the Chicago Zoological Society is to inspire conservation leadership by engaging people and communities with wildlife and nature. The Chicago Zoological Society is a private nonprofit organization that operates Brookfield Zoo on land owned by the Forest Preserves of Cook County. The Society is known throughout the world for its international role in animal population management and wildlife conservation. Its Center for the Science of Animal Care and Welfare is at the forefront of animal care that strives to discover and implement innovative approaches to zoo animal management. Brookfield Zoo is the first zoo in the world to be awarded the Humane Certified™ certification mark for the care and welfare of its animals, meeting American Humane Association’s rigorous certification standards. Open every day of the year, the zoo is located at 8400 31st Street in Brookfield, Illinois, between the Stevenson (I-55) and Eisenhower (I-290) expressways and also is accessible via the Tri-State Tollway (I-294), Metra commuter line, CTA and PACE bus service. For further information, visit CZS.org.