Put on a paw: a new implant will restore the ability to walk to sick cats and dogs

Russian scientists have created a biodegradable implant with shape memory function for the treatment of joint damage in animals. This is the first domestic product of its kind, combining both important properties, experts told Izvestia. The use of the development will make it possible to avoid repeated surgery, accelerate rehabilitation and eliminate complications. According to experts, the introduction of such a prosthesis will make the services of veterinarians more accessible, since now materials for such operations are expensive.

Fixation of a diseased joint in animals

NUST MISIS specialists have created a prototype implant for fixing diseased joints in animals, which can safely dissolve in the patient's body over time. Thanks to it, repeated surgery can be avoided. The material from which the development is made has a shape memory effect, which makes it possible to achieve a more accurate match of the prosthesis to the individual anatomy of a sick animal. This speeds up the rehabilitation process after surgery and makes it possible to avoid complications. The invention is designed to perform arthrodesis, an operation to immobilize a joint to eliminate chronic pain in animals with severe tissue damage.

Photo: MISIS

— Composite materials with shape memory effect are one of the innovative medical products for orthopedics, as they are able to provide qualitatively more functional osteoreconstruction. Since arthrodesis is necessary to support the regenerated limb, the material, along with biocompatibility, must match the characteristics of the tubular bones of the limbs in its mechanical properties. We hope that such designs will help speed up recovery and reduce the risk of complications in animals after surgery," said Polina Kachalina, a graduate student at the university's iPhD Biomaterial Science program.

To our bones: the first implants made of Russian biopolymers have been created in the Russian Federation

How do domestic dental materials compare favorably from foreign ones

Traditionally, metal structures are widely used in arthrodesis. For successful surgery, it is necessary to provide in advance the fixation of the articulated bones at a certain angle, which is determined individually and depends on the type of patient, his condition, the functionality of the reconstructed limb, the characteristics of the bone base of the operated area and the specific clinical situation.

To minimize the risks of complications and significantly accelerate recovery, researchers have developed experimental implant samples.

Photo: MISIS

The models were created using 3D printing from a bioresorbable polymer with a shape memory effect enhanced with mineral fillers: hydroxyapatite and silicon dioxide. This combination improves the strength of the structure and its compatibility with bone tissue.

The implant material resolves in the animal's body after implantation under the influence of various physiologically active factors. An additional shape memory bridge helps to accurately fix the joint in an anatomically correct position. This will reduce the burden on the body and reduce the risk of infection.

"The advantage of the proposed approach is to create individualized bioengineered structures to minimize lameness, ensure optimal compatibility of fixed joints and fix them in the position necessary to maintain the symmetry of the musculoskeletal system," said Natalia Anisimova, professor at the Institute of Biomedical Engineering at NUST MISIS.

Photo: MISIS

Experiments in the laboratory have shown that living cells attach well to the surface of the implant, and its decay products do not have a toxic effect on the body. In the coming year, scientists will test the samples' ability to self-install in the animal's body, and analyze their biocompatibility and effectiveness.

Functions of the new implant

Arthrodesis is usually performed involuntarily, as joint mobility is temporarily lost during this operation. And veterinarians strive to maximize their functional load, as it accelerates recovery. In fact, it is an "internal plaster" that is used when other methods are not suitable. It is given to both miniature animals, for example, dogs with complex multi-jointed fractures, and large ones with intra-articular fractures to give rest to the joint, Mikhail Shelyakov, a veterinarian of the highest category, told Izvestia.

— Biodegradable implants and shape memory implants have been used in veterinary medicine for a long time. However, combining these two properties in one product and improving it will make arthrodesis more affordable, as the materials for this operation are not cheap," said Mikhail Shelyakov.

Photo: MISIS

According to Associate Professor of the Department of Veterinary Medicine at RUDN University Arfeni Karamyan, the development can be considered extremely relevant and promising due to the high percentage of diseases of the musculoskeletal system in animals accompanied by pain, lameness and impaired functional activity.

— However, to confirm the effectiveness, a number of in vivo studies with the installation of an implant in laboratory animals and subsequent studies on target animals are required. The timing of bioresorption (the process of destruction of biomaterial in a biological environment) is also very interesting and whether it will be sufficient to help an animal," she said.

At the same time, the use of modern additive technologies and 3D printing is a very promising and relevant area in biomedicine and bioengineering, the specialist added.