When Heel Pain is not Plantar Fasciitis

Plantar Fasciitis is the most common cause of heel pain presenting in the clinic with millions suffering from this condition each year.

studies suggested that 10% of the population will suffer from heel pain at some point and 15% of all athletic and non-athletic adult population will report heel pain.

But does all heel pain caused by plantar fascia?

If the patient's pain is not localized to the attachment of the plantar fascia or if it does not resolve with conservative treatment. this should lead the practitioner to consider other possible causes of the patient's pain.

It is critical for practitioner to consider the wide range of possible differential diagnoses before coming to a conclusion on the aetiology of the pain.

there are around 40 conditions that could cause heel pain, check this list of these alternative aetiologies;

Plantar Heel Pain Differential Diagnosis

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let us take a closer look at these potential aetiologies and review different clinical exam and diagnostic findings that are common with each. there are also certain clues within the patient history that can lead you to an accurate diagnosis.

Tarsal tunnel syndrome

Is a rare entrapment neuropathy that involves compression of the posterior tibial nerve or one of its distal branches as it courses beneath the flexor retinaculum (laciniate ligament) along the medial heel.

Pain, burning, numbness and tingling in the heel that may radiate to the plantar aspect of the foot and into the toes may be present in patients with tarsal tunnel syndrome. However, this condition is often underdiagnosed, especially in patients with diabetes who may already have symptoms of peripheral neuropathy or lumbar radiculopathy.

It is important to consider conditions that may compress or irritate the tibial nerve at the tarsal tunnel.

Potential causes may include previous trauma to the area; pes planus that may stretch the contents of the tarsal tunnel; morbid obesity; space-occupying lesions (ganglion cysts, varicose veins, tumors, etc.); tendonitis in an active person from repetitive stress after running or walking; or increased oedema after excessive standing.

In a patient with chronic tarsal tunnel syndrome, there may be weakness of the intrinsic flexors and toe abductors of the foot.

In the more advanced cases, one may note muscle atrophy.

A comprehensive clinical examination is key to differentiating tarsal tunnel syndrome from other soft tissue causes of heel pain.

Symptoms will generally be unilateral. Besides palpating for a space-occupying lesion and percussing the nerve and its branches around the tarsal tunnel in search of a positive Tinel’s sign, the practitioner should also dorsiflex and evert the foot for five to 10 seconds, hoping to be able to reproduce the paresthesia the patient may be experiencing.

Be sure to have the patient stand and ambulate during the encounter to observe for any excessive pronation, supination or hindfoot malalignment that may give you clues as to the root of the cause.

MRI is an adjunctive imaging modality that can inspect for any soft tissue abnormality in or around the tarsal tunnel. However, to confirm a tibial nerve lesion, make sure to refer the patient to a neurologist for sensitive sensory and motor nerve conduction velocities (NCVs) as well as electromyography if initial conservative treatment fails.

The practitioner would look for increased distal latency in the nerve conduction velocity as well as fibrillation potentials that indicate axonal injury to the muscles innervated by the tibial nerve distal to the tarsal tunnel.

Initial treatment for the patient may involve the use of oral non-steroidal anti-inflammatory drugs (NSAIDS) for initial reduction of inflammation along with several weeks of rest, ice and elevation of the involved foot.

The practitioner could attempt to address the mechanism of injury by utilizing custom orthotics to correct foot posture and provide better support of the foot with ambulation. If the patient wears boots to ambulate or while he or she is at work, padding of the area could prove beneficial to reduce pressure and irritation to the nerve. If the patient does not improve with this measure, the next step would be to immobilize the foot for four to six weeks with the use of a CAM boot or splint along with corticosteroid injections and possible referral to physical therapy.

Depending on the success of the conservative treatment and the severity of the results from the diagnostic studies, the practitioner should consider a local nerve block before considering surgical treatment. If the pain ameliorates or completely subsides with the injection, then one might find success with subsequent decompression of the tibial nerve at the tarsal tunnel and its branches. Finally, if there is a space-occupying lesion present within the tarsal tunnel or adjacent area, it would be prudent to remove the lesion to reduce the pressure around the nerve.

Baxter’s nerve entrapment

Is a condition that typically consider after the patient has not benefitted much from aggressive conservative treatment. It involves compression or entrapment of the first branch of the lateral plantar nerve. This condition tends to be underdiagnosed and is often mistaken for plantar fasciitis due to the patient typically presenting with pain on the plantar medial aspect of the heel. On the contrary, Baxter’s nerve travels between the abductor hallucis muscle and the medial calcaneal tuberosity, running medial to lateral on the heel to finally innervate the abductor digiti minimi muscle. Some predisposing factors include obesity, overpronation, hypertrophy of the abductor hallucis muscle at its origin or increased inflammation secondary to chronic plantar fasciitis.

Both tarsal tunnel syndrome and Baxter’s neuritis share many symptoms I previously mentioned such as a deep ache and paresthesia, but without the sensory deficits. Accordingly, it is important to rule out plantar fasciitis, tarsal tunnel entrapment and other calcaneal pathology.