Posterior (rear) Heel Pain

Clinical appearance

Several structures in the posterior heel may cause distressing pain (Table 14) (34,35). One is a subcutaneous bursa between the skin and deep fascia. This adventitious bursa develops under a hard heel counter particularly in women who wear high heels. The Achilles tendon lacks a defined synovial sheath. Stresses on the Achilles tendon are enormous and often result in fatigue damage. Overuse and fluoroquinolone toxicity cause noninsertional tendinosis (tender swelling) 2-6 cm proximal to the calcaneal insertion. Interstitial rupture, which is clinically characterized by nodular thickening at this site, often portends a complete rupture. In contrast, Achilles enthesitis in the spondylarthropathies occurs at the calcaneal insertion, hence the designation insertional tendinitis. Wedged in the angle between the Achilles tendon and calcaneus is the retrocalcaneal or Achilles bursa. This heterogeneous structure (fibrocartilage front and back, synovium at the top) is an almost constant association of insertional tendinitis in the spondylarthropathies and is frequently involved by itself in rheumatoid arthritis. A frequent calcaneal deformity, Haglund's deformity, is a cause of posterior heel pain and is recognizable as a tender, hard lump high in the posterolateral calcaneus.

Differential diagnosis

The clinician's first task is to determine the anatomic location of the heel pain. More than one structure may be affected. An enlarged superficial bursa can be readily identified superficial to the Achilles tendon, which is best determined while the tendon is tense. Thickening and tenderness may be felt at the insertional or noninsertional Achilles tendon. The presence of nodules at the noninsertional area (in the absence of nodular rheumatoid arthritis and tophaceous gout) suggests partial rupture and is therefore a warning sign for a complete rupture. The extent and severity of the lesion can be fully disclosed by echography or MRI. Insertional tendinitis can be diagnosed clinically. A lateral x-ray of the heel may show an intrabursal effusion characteristic of retrocalcaneal bursitis.

Treatment

Superficial bursitis requires better shoes in the long run, but NSAIDs may be used temporarily. Noninsertional tendinitis patients should be referred to an orthopedist with broad experience in foot pathology, as tendon debridement or repair may be indicated. In fluoroquinolone-related cases, re-exposure to these agents should be avoided. Insertional tendinitis in the spondylarthropathies usually responds to systemic treatment. Refractory cases may be treated with a walking cast. Corticosteroid infiltrations in the retrocalcaneal bursa are very effective treatment but care must be taken not to infiltrate the tendon, which could lead to tendon rupture. Posterior heel pain from Haglund's disease may be improved with modified shoes and anti-inflammatory drugs. A wedge osteotomy that removes the posterior/superior corner of the calcaneus is curative and should be considered in chronically symptomatic cases. Ancillary measures for all types of posterior heel pain include the use of heel lifts to decrease traction on the Achilles tendon and gently performed tendon stretching exercises. Also, the use of a night splint that holds the foot at 90 degrees has been recommended for pain relief.

Role of the primary care physician

Posterior heel pain, with the exception of cases obviously caused by inappropriate footwear, should be best evaluated by specialists. Insertional Achilles tendinitis and retrocalcaneal bursitis are commonly seen in rheumatic disorders. On the other hand, noninsertional tendinitis could lead to complete tendon rupture. These patients, as well as patients with Haglund's disease, should be referred for orthopedic evaluation.

Key issues

Noninsertional Achilles tendonopathy should be considered as potentially leading to Achilles tendon rupture, even if induced by fluoroquinolones. Swelling at the distal portion of the tendon and the retrocalcaneal bursa is a sign of spondylarthropathy. In contrast, isolated bursal swelling is characteristic of rheumatoid arthritis.