Retrocalcaneal Bursitis

Inflammation of the retrocalcaneal bursa, a small synovial lined sac between the anterior surface of the Achilles tendon and the posterosuperior surface of the calcaneus, just proximal to the tendon insertion.

• Causes:
  • Mechanical: repetitive ankle dorsiflexion loading, runners, dancers, footballers and jumpers, and tight stiff backed shoes that press on the heel.
  • Haglund deformity (a prominent posterosuperior calcaneal tuberosity), a high arched foot, tight Achilles tendon, and varus heel alignment.
  • Insertional Achilles tendinopathy (the two coexist in most patients).
  • Inflammatory and crystal disease: spondyloarthritis (ankylosing spondylitis, psoriatic and reactive arthritis), rheumatoid arthritis, gout, and pseudogout.
  • Infection (rare): septic retrocalcaneal bursitis, tuberculosis.
• It affects young active adults and middle aged women (high heels), and bilateral involvement suggests inflammatory disease.
• Most patients improve within 6 to 12 weeks with conservative treatment, though a posterosuperior prominence leads to recurrent or chronic pain.

• Pain and swelling at the back of the heel, immediately in front of the Achilles tendon, aggravated by walking uphill, running, rising on tiptoe, and tight heel counters. Pain is often worst at the start of activity and after rest.
• Examination: tenderness on both sides of the Achilles tendon about 1 to 2 cm proximal to its insertion, a two finger squeeze test (pressure with a thumb and finger from either side just in front of the tendon gives a painful bulge), swelling, warmth, redness over the heel, and pain on passive dorsiflexion of the ankle (the tendon compresses the bursa). A visible bony prominence ("pump bump") may be present.
• The tendon itself is not tender in the midportion, and the calf squeeze test is normal.
• Differential diagnosis: insertional Achilles tendinopathy, superficial (calcaneal) bursitis behind the tendon, calcaneal stress fracture, Sever disease (children), plantar fasciitis, tarsal tunnel syndrome, os trigonum syndrome, enthesitis of spondyloarthritis, gout, septic bursitis, osteomyelitis, tumour, and Achilles rupture.
• Red flags: fever and rapidly spreading erythema (infection), bilateral heel pain with morning stiffness and back pain (spondyloarthritis), history of cancer, trauma, and inability to bear weight.
• Complications: chronic pain, tendon degeneration or rupture, secondary insertional tendinopathy, and, if infected, osteomyelitis.

• Clinical, with examination of heel alignment, calf flexibility and footwear.
• X-ray (weight bearing lateral heel) shows a posterosuperior calcaneal prominence, loss of the retrocalcaneal recess (the Kager fat pad triangle clouded by fluid), calcification, and spurs.
• Ultrasound shows bursal fluid and thickening, and guides aspiration or injection. MRI shows bursal fluid, calcaneal marrow oedema, Achilles tendon degeneration, and excludes stress fracture and infection.
• Blood tests when inflammatory disease or infection is possible: CRP, ESR, HLA-B27, urate, and rheumatoid serology. Aspirate and culture if infection is suspected.

• Offload and protect the heel:
  • Open backed shoes, sandals or shoes with a soft heel counter, and avoid stiff, high backed heels.
  • A heel lift of 10 to 12 mm (or a heel cup with a raised heel) in both shoes for 4 to 6 weeks to reduce Achilles compression of the bursa, then gradual reduction.
  • Pad or protect the posterosuperior prominence with a donut shaped pad or a heel cushion.
• Relative rest from aggravating activity (hills, running, jumping) for 2 to 6 weeks, with swimming or cycling for fitness.
• Analgesia: ice for 10 to 15 minutes, 3 times daily. Paracetamol 1 g orally 6 hourly. Ibuprofen 400 mg orally 8 hourly with food (or naproxen 500 mg 12 hourly) for 1 to 2 weeks. Topical diclofenac 1% gel 2 to 4 g 3 to 4 times daily.
• Physiotherapy: gentle gastrocnemius and soleus stretching (start only once pain is mild, and avoid forced dorsiflexion in the acute phase), calf strengthening, and eccentric loading of the Achilles on flat ground.
• Aspiration and injection: aspiration of a tense effusion gives relief. Corticosteroid injection into the bursa carries a risk of Achilles tendon rupture and fat pad atrophy, so avoid it as routine. If used for refractory aseptic bursitis, use methylprednisolone acetate 10 to 20 mg with lidocaine 1% 1 mL, ultrasound guided into the bursa only (not into or near the tendon), with the patient on a heel lift and protected from heavy load for 2 weeks, and no repeat injection.
• Extracorporeal shock wave therapy: 3 to 5 weekly sessions for persistent disease (evidence limited).
• Systemic disease: manage spondyloarthritis with NSAIDs and biologic therapy under rheumatology, gout with colchicine 500 micrograms 8 to 12 hourly for the flare and urate lowering therapy, and rheumatoid arthritis with disease modifying drugs.
• Septic bursitis: aspirate, culture and start flucloxacillin 1 to 2 g IV 6 hourly (or oral 500 mg to 1 g 6 hourly for mild disease) for 2 to 3 weeks, adding vancomycin 15 to 20 mg/kg IV 8 to 12 hourly if MRSA is possible, with surgical drainage if it fails to settle.
• Surgery for failure after 6 months of conservative care:
  • Endoscopic or open retrocalcaneal decompression: bursectomy with resection of the posterosuperior calcaneal prominence (calcaneoplasty) and debridement of degenerate Achilles fibres, with about 80 to 90% good results. Rehabilitation takes 6 to 12 weeks.
  • Dorsal closing wedge (Zadek) calcaneal osteotomy for a prominent posterosuperior calcaneal tuberosity. Lateral closing wedge (Dwyer) osteotomy for a varus heel.
  • Reattachment of the Achilles with suture anchors if more than half the insertion is detached during resection.
• Special groups:
  • Women with high heel use: switch to lower heels, and soft backed shoes.
  • Athletes: heel lifts during recovery, graded return, and attention to footwear.
  • Pregnancy: heel lifts, ice, paracetamol and physiotherapy. Avoid NSAIDs after 20 weeks.
  • Diabetes: monitor glucose after injection, and check feet.
  • Renal impairment and gastrointestinal disease: avoid oral NSAIDs.
• Follow up: review at 4 to 6 weeks. Refer to orthopaedics or sports medicine for failure by 3 to 6 months, a bony prominence needing surgery, suspected rupture, or inflammatory disease.