Achilles tendinopathy
Exam Tips
- In OSCEs, first exclude rupture before diagnosing tendinopathy: ask about sudden snap/kick sensation and perform calf squeeze test.
- Localize pain to classify subtype: mid-portion (2-6 cm proximal) versus insertional (distal 2 cm at calcaneal insertion).
- State that imaging is not routinely required in primary care when classic features are present.
- High-yield viva point: avoid the term 'Achilles tendinitis' because chronic pathology is usually degenerative tendinopathy.
- Safety point for prescribing stations: avoid steroid injection around the Achilles and review recent fluoroquinolone exposure due to rupture risk.
- When revising anatomy, use a tendon blood-supply diagram highlighting the hypovascular mid-portion watershed zone (commonly shown in MSK sports medicine texts).
Definition
Achilles tendinopathy is a clinical syndrome of activity-related Achilles tendon pain, local swelling or thickening, and reduced tendon function due to failed tendon loading adaptation rather than a purely inflammatory process. It most commonly affects the mid-portion of the tendon (about 2-6 cm above the calcaneal insertion, a relatively hypovascular zone), but can also involve the insertion at the posterior calcaneus.
Pathophysiology
The condition reflects a continuum of tendon overload and failed healing: repetitive tensile/compressive stress causes collagen disorganization, increased non-collagen matrix, neovascularization, and tenocyte dysregulation (tendinosis) rather than classic acute inflammatory tendinitis. Mid-portion disease is linked to high cyclical strain in a watershed blood-supply region, while insertional disease additionally involves compressive load at the tendon-bone interface (especially with dorsiflexion and rigid heel counters). Intrinsic factors (for example metabolic disease or biomechanical malalignment) and extrinsic factors (training errors, footwear, medications) alter tendon capacity, increasing pain and risk of partial/complete rupture.
Risk Factors
- Training overload (sudden increase in distance, speed, interval work, hill/sloping or hard surfaces)
- Previous Achilles/calf injury
- Biomechanical factors (leg length discrepancy, pes cavus, limb malalignment)
- Ageing tendon (middle age for mid-portion disease; older age for insertional disease)
- Diabetes mellitus
- Dyslipidaemia/hypercholesterolaemia
- Hyperuricaemia
- Inflammatory rheumatological disease
- Inappropriate footwear
- Drugs: fluoroquinolones (for example ciprofloxacin), systemic corticosteroids, local steroid injection around Achilles, statins, aromatase inhibitors
- Sports with repetitive running, jumping, sprinting (for example running, racket sports)
Clinical Features
Symptoms
- Gradual onset posterior heel or tendon pain, often aching (occasionally sharp)
- Pain worsened by loading (running, jumping, stair climbing) and local pressure
- Morning stiffness or stiffness after rest/prolonged sitting
- Mid-portion pain 2-6 cm proximal to insertion suggests non-insertional disease
- Pain and swelling at the calcaneal insertion suggests insertional disease
- Red-flag rupture history: sudden posterior leg pain, possible audible snap, difficulty push-off/weight bearing, sensation of being kicked
Signs
- Local Achilles tenderness on palpation (mid-portion or distal insertional 2 cm)
- Tendon thickening/nodularity; possible warmth or crepitus
- Asymmetry/swelling and pain on passive ankle dorsiflexion
- Reduced heel-raise endurance/hopping capacity due to pain and weakness
- Rupture signs on Simmonds/Thompson assessment: increased dorsiflexed resting angle, palpable gap (may be absent), absent plantarflexion on calf squeeze
Investigations
Management
Lifestyle Modifications
- If rupture suspected: urgent same-day orthopaedic pathway/admission per local protocol
- Relative rest and load modification (reduce provocative activity rather than complete prolonged immobilisation)
- Structured progressive calf-loading rehabilitation (typically eccentric/heavy-slow resistance) with physiotherapy
- Ice/cold packs after acute symptom flare for short-term comfort
- Address footwear issues; consider temporary heel lift and avoid rigid heel counter pressure in insertional disease
- Correct training errors and gradual return to sport when pain and function improve
- Manage contributing conditions (for example diabetes, dyslipidaemia); stop fluoroquinolone where possible after discussing antibiotic alternatives
Pharmacological Treatment
Simple analgesic
- Paracetamol 1 g orally every 4-6 hours when required (maximum 4 g in 24 hours)
First-line for pain; reduce maximum daily dose in low body weight, frailty, liver disease, or chronic alcohol excess.
NSAID (short-term analgesia only)
- Ibuprofen 200-400 mg orally three times daily with food (use lowest effective dose for shortest duration)
- Naproxen 250-500 mg orally twice daily if stronger NSAID needed
Useful in early painful phase for analgesia, but avoid routine long-term use as tendinopathy is not primarily inflammatory. Avoid/caution in CKD, heart failure, ischaemic heart disease, uncontrolled hypertension, peptic ulcer/GI bleed risk, anticoagulant use, and pregnancy (especially third trimester). Consider gastroprotection (for example omeprazole 20 mg once daily) in higher GI-risk adults.
Surgical / Interventional
- For confirmed acute rupture: operative repair or functional non-operative protocol in specialist care
- For persistent disabling tendinopathy despite prolonged optimal conservative treatment (commonly >=3-6 months): specialist procedures such as debridement/excision of degenerate tendon, calcaneal prominence resection (in insertional disease), and tendon augmentation/transfer in selected cases
Complications
- Achilles tendon rupture
- Chronic pain with reduced function in work, daily activity, and sport
- Reduced athletic performance/deconditioning
- Psychological impact in chronic cases (for example anxiety/depressive symptoms)
- Post-operative complications if surgery required (notably wound problems)
Prognosis
Most patients improve with conservative care, with meaningful pain and functional gains often evident by around 12 weeks, but recovery can be prolonged and symptoms may persist for many months (occasionally up to 2 years). Long-term outcomes are generally favourable, though recurrence and contralateral tendon symptoms are not uncommon; delayed diagnosis of rupture worsens outcome.
Sources & References
🏥BMJ Best Practice(1)
✅NICE Guidelines(1)
- Achilles tendinopathy[overview]