Health Matters – classic
Tendonitis may lead to deformed foot
Editor’s note: This column originally appeared in The Mining Journal on July 20, 2020.
Humanity comes in all shapes and sizes, the variety of which never ceases to amaze me. There’s the obvious stuff, like age, sex, hair and skin color. Then there is the important stuff, like an individual’s biochemistry, or, for example, their immune system function. Many critical components of health and vitality are primarily a function of genetic factors. As the saying goes “you can’t choose your family”. It remains so true. Genetics can be cruel. How about inheriting a crippling disease like one of the muscular dystrophies?
Our DNA also determines our skeletal structure. When referenced, some might imagine simply the set of one’s jaw or a person’s general body type. How about a slight extra curvature of the leg, changing how you walk for the rest of your life. An individual’s skeletal architecture is genetically determined, and goes a long way toward determining how well it works.
A scene oft-repeated in a primary care practice is as follows. A middle-aged individual happens to mention to their primary care provider they have been experiencing some aching from the inner side of their foot. The provider, seeing no significant swelling or redness, assumes this is not an acute injury and recommends an anti-inflammatory. And, indeed, while taking the medication, the individual so afflicted notes their foot indeed feels better.
Pain from the inner side of the arch is often due to stress and strain on a specific structure sometimes referred to as the arch tendon. The most simplistic diagnosis possible is tendonitis, at least early on. The posterior tibial tendon serves the vital function of raising the arch at a certain point in the gait cycle. Someone born with a certain foot type is set up to develop this progressive tendon disease, a condition more accurately called Posterior Tibial Tendon Dysfunction. It is due to a common situation: the bone composing the bottom half of the ankle joint, the talus bone, is able to slightly “slip” off the heel bone, which is its supporting surface. Over the years, the results can be devastating.
For the average person, the discomfort worsens with activity, so naturally they tend to reduce their levels of physicality. Many assume this is a problem that will heal with rest and, it is true, the inflammatory changes in the tendon can. But the cycle of activity-inflammation-pain recurs when weight-bearing is resumed. The problem is foot structure, one of those genetically-determined conditions. The physical stress to the tendon will recur whenever the sufferer stands or walks enough. It is their foot type which is the root of the problem.
The key to the destructive and progressive nature of this foot type is the gradual degenerative changes which occur to this tendon. Consequently, other structures are affected, many of which are essential for foot alignment. Thus, chronic posterior tibial tendonitis often leads to a gradual collapse of the arch. Over the years, a real and obvious deformity results. Hence, another term for this problem is ‘Acquired Adult Flatfoot Deformity.’ This is not seen in young people; they haven’t been ‘weight bearing’ long enough!
This on-going disease process got its name because of the functional changes which occur to the foot, lower leg, pelvis and back. As the tendon loses function, the inner arch of the foot collapses. Typically a subtle and gradual development, it can occur suddenly. The suffering individual will often exclaim how their arch suddenly fell, due to an acute tearing of the tendon.
The positioning of the talus bone progressively changes, slowly collapsing off its supports. But because this bone is locked under the lower leg, excessive rotation of the talus also causes the lower leg to. This pathologic internal rotation results in stress to the knee and low back. Although well documented, many health care providers aren’t able to make the connection.
Unfortunately, this condition is more prevalent than ever. Some of the reasons for this include an increasingly overweight population and an aging population. Presentation varies greatly, depending on a host of factors. One’s occupation is of importance, with those standing more on hard or uneven surfaces suffering more. Other risks include the presence of diabetes, various arthritic diseases, even high blood pressure.
If left unchecked, PTTD can be a seriously disabling condition. Without effective treatment, deformity can lead to degenerative changes in the cartilage of the knee, the ankle and various foot joints. Many disparate parts are afflicted. Because of the change in positioning of the foot, joints seemingly unrelated will often become symptomatic, confusing developments to the non-specialists.
The type of treatment most effective is determined by the stage of deformity when therapy is instituted. If early in this predictable course of events, the prognosis is excellent, and many of the consequences of PTTD can be avoided completely. Proper and early use of foot orthotics (along with the correct shoes) can halt and even reverse its effects. Unfortunately, many of those individuals dealing with PTTD receive foot supports little better than over-the-counter devices. Orthotic prescribing is exceedingly complex, with most health care providers unfamiliar with the nuances of the fitting process. But when properly prescribed, these are an extremely effective therapy, easy to use, with many benefits.
When insufficient treatment has been utilized and the deformity has progressed sufficiently, degeneration of the foot joints can advance to the point fusion of the joints is the only option. As expected, this surgery will drastically alter foot function. Naturally, body mechanics are negatively affected. For those where operative intervention is not an option, various braces are available, although these are often cumbersome and unwieldy.
Many simple, conservative measures are used for an inflamed tendon, but these don’t address the root of the problem. Topical pain relievers, icing, injections, none of these address the mechanical nature of the problem. Even physical therapy, routinely prescribed for this, does not alter the structural origin. Exercises strengthening the posterior tibial muscle are recommended as an adjunctive therapy, but soft tissue cannot overcome poor bone support. Like so many problems, the longer this goes without appropriate and effective treatment, the worse it gets and the more damaged the foot becomes. In addition, the treatment required to get pain relief gets more complex and more expensive.
If caught before the degenerative changes in the tendon or joints has developed, a specialized implant can be the placed into the articulation below the ankle, termed the sub-talar (which is the apex of the deformity). This device blocks the abnormal motion, thus keeping the posterior tibial tendon from being pulled on too much. The tendon never becomes diseased because the excessive physical forces are not allowed to develop. It is vital when developing a treatment plan to understand the crux of the problem is the inherited foot alignment and mechanics, not the ‘sick’ tendon.
Hopefully, the previous discussion has led the reader to understand the critical element of time. If you are having pain from the inner side of the ankle and foot, get it evaluated and treated. Don’t wait for permanent changes to these critically important structures. It is an oft-repeated refrain: when sound treatment is provided early in the process, the easier it is to get relief. Plus, less damage occurs. Maybe all it takes is “just” some arch support placed inside your shoe. They may look simple, but, when properly prescribed, foot orthotics can make all the difference in the world.
Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula. Dr. McLean’s practice, Superior Foot and Ankle Centers, has offices in Marquette and Escanaba, and now the Keweenaw following the recent addition of an office in L’Anse. McLean has lectured internationally, and written dozens of articles on wound care, surgery, and diabetic foot medicine. He is board certified in surgery, wound care, and lower extremity biomechanics.