Fat pad syndrome: More diffuse pain than plantar fasciitis
The plantar surface of the heel is protected by a thick fat pad. Those at risk of a thinned fat pad include the elderly (the pad thins with age), the obese (increased stress to the pad), and those who have previously received a corticosteroid injection in the pad. Cumulative or acute trauma to the heel can also cause contusion to the heel pad.
Evaluation. Pain typically is located more posteriorly than classic plantar fasciitis pain and is more diffuse. Pain from the fat pad should not radiate toward the arch and is not exacerbated by dorsiflexion of the foot.1
Treatment. Recommend relative rest, gel heel cups, NSAIDs, and ice.37
Less common causes of plantar-surface pain
Lateral plantar nerve entrapment may also cause neuropathic pain on the plantar surface. Patients who experience a painful pop in their heel associated with trauma may have ruptured their plantar fascia. A fallen arch may also be noted on exam. Treatment of both of these conditions is similar to that of plantar fasciitis.
Acute calcaneal fracture results from trauma, such as a fall from a height onto the soles of the feet. Look for localized pain and swelling around the calcaneus and evaluate the neurovascular status of the foot. Initial treatment includes elevating the foot, avoiding weight bearing, applying ice, controlling pain, and using a posterior splint. Many of these fractures require surgical fixation.
Medial heel pain
Posterior tibial tendonitis/dysfunction and tarsal tunnel syndrome are best classified as medial in location (FIGURE 1C). However, the pain is often more diffuse and may radiate to either the posterior or plantar heel.
Posterior tibial tendonitis/dysfunction are linked to obesity
Posterior tibial tendonitis (PTT) and posterior tibial tendon dysfunction (PTTD) are related diagnoses. PTTD refers to increased laxity of the tendon resulting in flat foot and increased heel varus. It is the most common cause of acquired flat foot in adults. PTT may exist separately or as part of PTTD.
Evaluation. Patients complain of pain at the posterior edge of the medial malleolus that may extend toward the arch of the foot.38,39 Patients may also experience swelling or redness in the area. Both PTT and PTTD seem related to overuse and obesity. Young or nonobese patients with PTT or PTTD often have underlying systemic arthropathies.35
Treatment. Early treatment is necessary to prevent progression of tendon incompetence. Interventions include weight loss, NSAIDs, icing, physical therapy,40 and orthotics or bracing for arch and ankle support. You may also try immobilization in a short leg cast for 6 weeks.41 If conservative measures fail, surgery may be necessary for tendon repair, tendon transfer, calcaneal osteotomy, or tarsal bone fusion.38,39
Tarsal tunnel syndrome: Pain can occur at night
Tarsal tunnel syndrome (TTS) is the most common compression neuropathy of the lower extremity. The tarsal tunnel is a fibro-osseous structure along the medial ankle that contains the tibial nerve, the posterior tibial artery, and the tendons of the tibialis posterior, flexor digitorum longus, and flexor hallucis longus. The posterior tibial nerve can become irritated as it runs through the tunnel. The inciting incident can be either a severe stretch to the nerve (from a medial ankle sprain) or from an anatomic compression. Pes planus foot or posterior tibial dysfunction have also been implicated as common causes.1
Evaluation. Patients describe poorly localized pain with numbness and burning along the medial ankle, arch, or heel, with radiation proximally.42,43 Symptoms are aggravated by exercise, and night pain is not uncommon. The tenderness of TTS is more diffuse than that from plantar fasciitis, and symptoms are evident directly over the tarsal tunnel itself.
The classic finding is a positive Tinel’s sign (reproduction of symptoms by tapping over the posterior tibial nerve as it passes through the tarsal tunnel). Placing the foot in dorsiflexion and eversion may also reproduce symptoms.1
Imaging results are not always definitive, but can be helpful in determining the cause of the compression. Plain films and CT can detect fracture or bony deformity, while MRI is more helpful in evaluating soft-tissue structures, such as ganglions or varicosities. Abnormal nerve conduction studies can be suggestive of TTS, but a normal result does not rule out the diagnosis.
Treatment follows a stepped progression. Initially try activity modification, orthotics, and physical therapy. Physical therapy concentrates on medial arch strengthening, Achilles stretching, and ankle proprioception exercises.