Practice Perfect 825
The Making Practice Perfect Decisions Series
Part 2 - Clarify the Underlying Cause

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Clinical decision making can be quite challenging in today’s modern podiatric medicine and surgery, but don’t worry. We’re here to help with our ongoing series, Making Practice Perfect Decisions. Last week, we discussed a first fundamental step which is determining the damaged anatomy through the use of the history and physical examination. 

This week we discuss the next important step, clarifying the underlying biomechanical cause. The vast majority of foot and ankle deformities have some type of mechanical component, and it is that component that causes or has caused the damage to the anatomic structure determined in Part 1 of our series. One can also think of this as considering the pathophysiology of the particular disorder.

Think of a 35-year-old African American male patient with hypertension. In order to properly prescribe an antihypertensive, it is important to know the pathophysiology behind that particular patient’s disease. A physician would not randomly prescribe a medication from a list of possibilities. Instead, it is necessary to understand what is causing his blood pressure to elevate. Is this essential hypertension or something else? Further investigation shows a narrowed renal artery. A procedure is performed, and the patient does well. Success was achieved by understanding the disease.

Similarly, we must do the same for our patients with foot and ankle disorders. Let’s discuss a very common diagnosis: plantar fasciitis. Rule one had us determine the damaged anatomical structure, which is obvious from a history and basic physical examination: the plantar fascia. As easy as the initial diagnosis is to make, it requires a good understanding of the patient’s biomechanics to understand the pathophysiology and initiate proper treatment. Fundamentally, plantar fasciitis/osis is a degenerative condition of the plantar fascia caused by increased pull or load on the ligament. There are extrinsic and intrinsic risk factors to consider. External factors may include poorly supportive shoes, hard surfaces, and obesity, while intrinsic factors cause an extra pull on the ligament (subtalar pronation with forefoot supinatus, flexible forefoot valgus, forefoot varus, and ankle equinus). Again, the common factor with all of these is increased pull on the fascia. A proper lower extremity examination will determine which of these factors – or perhaps others - play a role. For example, genu valgum may increase subtalar pronation, or the presence of a limb length difference may participate.

It is the focus on treatment of these specific factors that should make up the basis for deciding what to do. Instead of randomly picking some treatments from a list, like the thoughtless doctor who treats all patients with hypertension with the same medication, understanding the biomechanical causes of a particular patient’s plantar fasciitis will allow targeted interventions. For example, proper supportive shoes, orthoses with modifications to reduce plantar fascial strain, and stretching/night splints are most often effective. The use of steroid injections, then, does not treat the cause but rather symptoms, and it should only be used in very specific instances where it is deemed necessary.

A good examination will also help the provider rule out other potential differential diagnoses. For example, certain neurological tests will eliminate lumbosacral radiculopathy or tarsal tunnel syndrome as potential etiologies. Clarifying the underlying biomechanical cause then consists of understanding the specific patient’s pathomechanics while also eliminating other etiologies. 

With this rule in mind, the astute lower extremity specialist will be ready to move on to the next step, which is treating the specific biomechanical fault. More on that next week.

Best wishes.

Jarrod Shapiro, DPM
PRESENT Practice Perfect Editor
[email protected]