Tendons are essential for transmitting forces from muscles to bones to making them move during locomotion. When injury occurs, that all-important tissue can tear. As if that isn’t bad enough, new research is showing that when those injuries occur to tendons covered by a synovial sheath, the inner tendon cells can be exposed to lubricating synovial fluid—a substance researchers recently determined is toxic for them. | Photo: iStock

Your horse’s body can’t function without tendons. These soft-tissue structures are essential for transmitting forces from muscles to bones to making them move during locomotion.

When a tendon injury occurs, that all-important tissue can tear. As if that isn’t bad enough, new research is showing that when those injuries occur to tendons covered by a synovial sheath, the inner tendon cells can be exposed to lubricating synovial fluid—a substance researchers recently determined is toxic for them.

Synovial fluid is in constant contact with tendons. But the tendon’s outer layer contains cells that are resistant to synovial fluid’s toxic nature. Once that outer layer is breached in certain types of injury, the cells on the inside of the tendon become exposed to the synovial fluid, which kills them, said Jayesh Dudhia, PhD, FHEA, a senior researcher in the Royal Veterinary College (RVC) Department of Clinical Sciences and Services, in Hertfordshire, UK