Achilles Tendinopathy
A degenerative overuse disorder of the Achilles tendon characterised by pain and impaired performance; distinct midportion and insertional subtypes are recognised.
Overview
Achilles tendinopathy is a failed healing response with disorganised collagen, neovascularisation, and absent classical inflammation. Midportion tendinopathy occurs 2 to 6 cm proximal to the calcaneal insertion; insertional tendinopathy is associated with a Haglund deformity and enthesopathic changes. Risk factors include training errors, calf weakness, metabolic disease, and fluoroquinolone exposure.
Epidemiology
Lifetime incidence in runners is 10 to 30 percent. Peak age is 30 to 50 years with a male predominance in athletic populations. Incidence rises in sedentary patients after the age of 60.
Symptoms
Gradual onset of posterior heel or mid-Achilles pain, morning stiffness, and pain at the start of activity that may ease during exercise. Focal tenderness, fusiform thickening, and a positive arc sign help localise pathology. Insertional disease produces calcaneal tenderness and pain with dorsiflexion.