Plantar Heel Pain (under the heel)

Clinical appearance

Plantar heel pain is frequently encountered in general medical practice (36,37). The pain is maximal when the patient first stands in the morning and tends to decrease with walking. There are 4 clinical contexts in which the symptom develops (Table 15). Fat pad failure is seen in obese patients with attrition of the plantar fat pad, in patients with a thin and flabby plantar pad, and as an iatrogenic condition in patients who sustained multiple plantar corticosteroid infiltrations for heel spurs. "Plantar fasciitis" is seen in runners with interstitial fascial rupture, in patients with flat, pronated feet in whom a collapsed longitudinal arch stretches the fascia, and in patients with spondylarthropathy and enthesitis at the calcaneal insertion. The tarsal tunnel syndrome results in plantar pain and paresthesias. It is due to a pressure neuropathy of the calcaneal branches of the posterior tibial nerve or the first branch of the lateral plantar nerve. Both are more likely to occur in patients with flat, pronated feet from excessive pressure on the medial edge of the heel. Stress fractures of the calcaneus and calcaneal cysts can also cause plantar heel pain.

Differential diagnosis

Fat pad failure pain is associated with central tenderness in the heel pad. Interstitial rupture hurts diffusely in the proximal plantar fascia. Traction enthesopathy and spondylarthropathy-related enthesitis cause tenderness at the medial calcaneal tubercle, which is the main insertion site of the plantar fascia. Entrapment neuropathy is characterized by a positive Tinel sign when the medial edge of the heel is percussed. Bone-type calcaneal pain can be readily detected by firmly squeezing the heel from the sides. An MRI or a bone scan will reveal the osseus lesion. It should be noted that a well-developed heel spur is frequently present in painful heels. However, similar spurs are often present in the asymptomatic contralateral heel. Furthermore, heel spurs are equally frequent in patients with and without heel pain, which further detracts from their clinical significance. On the other hand, ragged, poorly developed (inflammatory) spurs are often present in patients with spondylarthropathy (Figure 6). These spurs are not seen in normal individuals.

Treatment

Plantar heel pain should be treated with nonspecific measures, along with treatment aimed at the underlying condition (38). A heel cup, a firm plastic device that squeezes the plantar fat pad at its edges and increases its thickness, helps most patients. Anti-inflammatory drugs help, particularly in patients with spondylarthropathy. Achilles tendon and plantar fascia stretching exercises are useful once the condition becomes inactive and may help prevent recurrences. Corticosteroid infiltrations can be quite helpful in patients with an inflammatory cause. Because the procedure is technically difficult and very painful, it is generally reserved for those patients who have not benefited from a more conservative program including NSAIDs in full doses for 6 weeks. Additional measures that have been reported to be useful include a night splint that holds the ankle at 90 degrees and dexamethasone iontophoresis. Laser therapy was found ineffective in a well-designed controlled trial. Because spurs do not cause the pain in noninflammatory cases, they should not be surgically removed. Plantar fasciotomy is a salvage procedure for severe, long-standing cases (39). There is a partial collapse of the longitudinal arch following this procedure.

Role of the primary care physician

Primary care physicians should be aware of the major types of plantar heel pain (mechanical and inflammatory) and be able to implement basic treatment. Patients with inflammation may require referral to a rheumatologist, whereas patients with traction enthesopathy and tarsal tunnel syndrome should be referred for orthopedic evaluation. The suspicion of a bone origin of pain should lead to investigation by bone scan or MRI.

Key issues

Plantar calcaneal pain is caused by fat pad failure; plantar fascial pain by interstitial rupture, traction enthesopathy, or enthesitis; bone pain from fatigue fracture and bone cysts; and pain and paresthesias by pressure neuropathy. Each has different treatment implications.