Researchers from a leading engineering program in Japan have uncovered how salamanders can rapidly restore damaged tendons. The findings were reported in a peer-reviewed orthopedic science journal.
When a tendon tears, recovery often requires months of rehabilitation before athletic activities can resume. In contrast, newts repair similar injuries within about three months and leave little to no scar tissue behind.
The study compared a model of salamander tendon regeneration with tendon repair in mice, using the same flexor tendons located in the middle finger of the hind limb as a common point of reference for both species. Six weeks after injury, salamanders formed new tissue that looked like tendon tissue, and by twelve weeks the regenerated tissue demonstrated strength on par with healthy tendon. In mice, however, the healing tissue remained dissimilar to healthy tendon tissue, and even after twelve weeks its strength fell short.
Ultimately, salamander tendon tissue connected the original tendon segments, while mice showed patchy scar tissue filling the damaged area. Researchers also noted a higher density of cell nuclei near where new tissue met the residual tendon in the amphibians.
“Initially, weak, small tendons emerge and, over time, they remodel to gain strength and stiffness. If we can imitate this simple regeneration approach, athletes might recover more fully without invasive surgery,” said one of the study’s authors.
Earlier work in the field has explored materials to support bone regeneration, illustrating a broader interest in translating natural repair strategies into clinical options.