Have you ever heard the expression
“Motion is lotion?” In the world of surgery and rehabilitation, this phrase is known to be true. When a tendon is torn and then repaired, early passive motion helps speed up healing. Passive motion means that the injured joint is carefully moved without using the muscles. No one knows exactly how or why early movement has a healing effect.
While scientists continue to study the hows and whys of early motion and faster healing, others are asking, “If early motion works so well, can added force increase the strength of the tendon fibers?” Researchers used dog models to see the effects of two different levels of force on the tendon that bends the animal’s paw and lower leg.
By applying a force three to six weeks after surgery, the researchers expected to see many new tendon fibers. They also thought they’d find more links or connections between the fibers, as well as thicker tendon fibers and faster healing of the repaired tendon. None of these changes were seen. Despite added forces, no major differences were found in the size, shape, or number of tendon parts.
This study actually raised more questions than it answered. Would a different force work better? Does the tendon heal faster with a force applied earlier (or later) during healing? If force doesn’t change the tendon, what does? This experiment will help scientists plan other studies to answer these questions. Knowing how tendon strength increases will help doctors and other rehabilitation specialists decide the best way to treat someone after flexor tendon surgery.