Either way, the explosion of these troublesome injuries occurring in an aging population that seeks to stay young and remain active has created a medical conundrum: How should they be managed? Can these injuries heal with rest and rehabilitation or be repaired using surgical techniques? Over the decades, rehabilitation medicine has taught us that rest combined with exercise can heal many if not most of these problems. But this regimen takes time, and not uncommonly, it may evolve into a long, drawn-out process. And who has the patience for that? Certainly not my septuagenarian squash player scheduled to defend his national title in the upcoming months. Sometimes, the results of conventional therapy can be disappointing. Although some function is restored, the pain may persist.
The importance of having healthy tendons is obvious. Without them, motor activities become challenging, if not impossible to perform.
Tendons are uniquely sensitive tissues that are capable of converting mechanical forces to biochemical signals that elicit cellular responses by tendon cells. Interestingly, the specific structure of tendon is not determined by the expression of type I collagen—its most abundant component—but only by the specific parallel organization of its type I collagen fibrils.5 For example, rotator cuff tendons differ considerably from finger or Achilles tendons. Fibrils fan out and spiral in all directions as the tendon courses from its bony insertion, the enthesis, an area rich in type II collagen, toward its muscle partner. This intricate spatial arrangement is necessary for the tendon to be capable of performing its assigned activity, be it shoulder rotation, delicate finger pinching or leaping into the air. The great Italian polymath, Leonardo da Vinci, illustrated this marvel of nature in his 15th century drawings of the flexor digitorum superficialis tendon.
When Tendons Hurt
Tendons get injured when their highly organized hierarchical collagen structure is disrupted. As a result, there is collagen fibril disorganization, increased proteoglycan and glycosaminoglycan content, hypercellularity and neovascularization, all hallmarks of injury and attempted repair.5 These cellular and molecular changes modify the mechanical properties of tendons and cause pain.
To be a rheumatologist is to regularly deal with the sundry forms of tendonitis. Sometimes, this may appear to be more of an art form than a science. Thermal modalities, such as ice and heat, can sometimes help, but in the short term, there may be no better remedy than the time-tested corticosteroid injection. As one of my great mentors, Ron Anderson, MD, used to advise fellows managing such patients in clinic, “Extend the needle of friendship!”
