In my blog last month (http://tinyurl.com/bd5ucac  ), I reviewed the common disorders of the posterior heel and Achilles tendon. Since we are in the neighborhood, so to speak, l will give you my cheat sheet for addressing pain syndromes of the plantar heel.
I am sure we can all agree that plantar heel pain is the most common orthopedic complaint of patients who seek our advice and treatment. It is such a common disorder that most of these patients tell us that they have plantar fasciitis before we even touch them. The odds are that they are correct.
Just like any patient encounter, the history taking is very important in that it typically narrows down your diagnosis and one can subsequently confirm this by the physical exam and X-rays. I find that heel pain is one of those conditions that we get burned out on and unfortunately we tend to rush through these patient encounters too quickly. When it comes to obtaining the patient history, key components include:
* the presence or absence of post-static dyskinesia;
* if there is post-static dyskinesia, how much of the pain can be “walked out"?;
* location of the pain;
* any element of nerve pain (burning, tingling, or numbness);
* any history of swelling, redness or heat to the heel; and
* any history of excessive activity/injury.
Post-static dyskinesia is a typical symptom of most inflammatory orthopedic conditions including arthritis, tendinitis, enthesopathies and bursitis (with the notable exception of infracalcaneal bursitis). If there is post-static dyskinesia and the patient can walk out most of the pain, this suggests that equinus (tight Achilles complex) is a major contributing factor. These patients really need to be stretched out. If there is no element of post-static dyskinesia, then plantar fasciitis is less likely in your working diagnosis. Infracalcaneal bursitis, for example, would be on the top of your list because it is less likely to be painful getting out of bed and it seems to get worse as one walks. Bursitis tends to be especially bad at the end of the day with the feeling of walking on a stone in the center of the heel.
Plantar fasciitis and infracalcaneal bursitis do not have findings of redness, heat or swelling of the heel. When these symptoms and findings are present, one needs to consider a stress fracture and rule it out.
What about nerve pain in the heel? I have always been amazed at how many podiatrists tout “medial calcaneal nerve” entrapment. I don’t know about you but it seems unlikely that such a small twig of sensory nerve to the medial heel would be such a culprit for plantar heel pain. If you press on a nerve hard enough, you will evoke pain. Does it exist? I am sure it does and I have read case reports about it from the 1970s, but most likely, it is over diagnosed and misunderstood. After 15 years in practice, I have not had to do a nerve decompression/resection of the medial calcaneal nerve to resolve heel pain. Now, certainly if a patient has had trauma to the medial heel or a prior surgery (i.e. a DuVries open heel spur resection), nerve entrapment is a more of a possibility and one should not discount this.
The real cause of nerve-related heel pain is entrapment neuropathy of the first branch of the lateral plantar nerve. As the posterior tibial tendon splits into the medial and lateral branches on the medial aspect of the heel, the first branch of the lateral plantar nerve dives laterally through the deep fascia of the abductor hallucis muscle and the medial plantar margin of the quadratus plantae muscle. The nerve continues laterally under the calcaneus and spur (if present). Risk factors for nerve entrapment of the first branch of the lateral plantar nerve include concomitant plantar fasciitis, hypertrophy of the abductor muscle and or accessory muscles, obesity and excessive foot pronation.
In short, the main differential diagnoses for common causes of plantar heel pain include plantar fasciitis, entrapment neuropathy of the first branch of the lateral plantar nerve, infracalcaneal bursitis and calcaneal stress fracture. Certainly, there are other causes of heel pain that are less common. These etiologies include systemic arthritic conditions, Reiter’s disease, bone and soft tissue tumors, crystalline arthropathies, neurologic conditions of the spine, sarcoidosis, Paget’s disease of bone and local infections.
So how do you systematically examine patients with heel pain? Do you press your thumb on the plantar medial heel where the arch and heel meet, and say, "Does that hurt?” Well I do that too but that is at the end of the exam. My typical exam is to first palpate the central band of the plantar fascia and stop before reaching the heel. That will tell me if there is any element of distal fasciitis. More often than not, patients do not have pain there and tell me that it tickles.
I then proceed to palpate the abductor region of the medial heel to assess for nerve entrapment of the first branch of the lateral plantar nerve. If it is tender, I will ask the patient try to abduct the pinky toe (bilaterally) to determine if there is any motor weakness. The first branch of the lateral plantar nerve is a mixed sensory and motor nerve innervating the abductor muscle to the fifth toe. Then I palpate the distal Achilles tendon, the retrocalcaneal bursa and finally squeeze the heel. This will rule out concomitant Achilles tendinitis, retrocalcaneal bursitis and stress fracture respectively. If the heel is warm to touch, swollen and sore to squeeze, you can bet the ranch that the patient has stress fracture.
Now that you have narrowed down your diagnosis, take X-rays to rule out any obvious pathology such as stress fracture, tumor or heel spur. Certainly, the heel spur rarely causes pain unless there is a frank lack of fat pad with bursitis. Even though it has been postulated that the nerve can be irritated by the plantar heel spur, I don’t remove the plantar heel spur and pain resolves with standard decompression surgery. This gives further anecdotal evidence that the spur has minimal to no bearing on the condition(s). Remember, stress fractures of the heel are hard to see and there is a two- to three-week lag time before you will see the classic sclerotic band at the superior aspect of the heel.
In regard to bursitis, I typically employ a viscoelastic heel cushion, have the patient avoid walking barefoot in the house and him or her avoid using sandals, slippers and flip flops. Other conservative measures include anti-inflammatory medication, rest, icing and sometimes immobilization. I do use cortisone injections for bursitis. However, I am very careful and judicious in using it in the case of any patient that has a lack of a plantar fat pad. Rarely does this condition require surgery.
One uses immobilization, rest, ice and compression to treat stress fractures. The good news is that stress fractures always heal and never require surgery. I will have patients tell their primary care physicians about the stress fracture so they can be worked up for osteoporosis (assuming the patient is older). For young patients, it is usually a fatigue fracture versus an insufficiency fracture and related to running or other overuse activity.
When it comes to plantar fasciitis with or without nerve entrapment of the first branch of the lateral plantar nerve, clinicians treat this the same way from a conservative standpoint. Conservative measures may include an Achilles stretching protocol, ice massage of the plantar fascia, the use of stiff soled shoes with arch support (orthotics) and anti-inflammatory medication including cortisone. I use 40 mg of kenalog in local anesthesia for my cortisone injections. I give them one month apart as necessary and up to three injections per 12 months.
The main difference in treatment protocol for plantar fasciitis versus entrapment neuropathy of the first branch of the lateral plantar nerve is with surgery. If a patient has failed conservative care for his or her heel pain (three cortisone injections, physical therapy, shoe modification/arch support, etc.), then I recommend surgery. If I have the slightest -- and I mean slightest --- evidence of the contribution of heel pain from nerve entrapment, I will perform the standard oblique incision over the medial heel to release the abductor muscle fascia circumferentially and do a partial plantar fasciotomy. I have never beat myself up for performing the decompression with plantar fasciotomy in a patient but can’t say the same for the contrary. If I am convinced that the heel pain is strictly plantar fasciitis, then I will perform an instep partial plantar fasciotomy.
In conclusion, rather than simply poking your thumb on the plantar medial heel and say “yup ... you have plantar fasciitis,” do a thorough exam and rule out other concomitant problems such as disorders of the Achilles tendon and nerve entrapment which often cloud the diagnostic picture and contribute to failing conservative and surgical treatments. I find this when patients present with continued heel pain following a plantar fasciotomy. More often than not, the nerve entrapment was not identified and addressed. Fortunately for us, 90 percent of the time, treatments for “plantar fasciitis” will resolve heel pain regardless of its etiology. It is the other 10 percent that keeps you scratching your head and spinning your wheels.