Achilles Tendon Disorders

Achilles Anatomy & Biomechanics - Foundation First

• Origin: Gastrocnemius & Soleus muscles.
• Insertion: Calcaneus (posterior aspect).
• Nerve Supply: Tibial nerve (S1, S2).
• Blood Supply: Branches from posterior tibial & peroneal arteries.
  • Critical watershed zone: 2-6 cm proximal to insertion (hypovascular).
• Biomechanics:
  • Primary ankle plantarflexor.
  • Essential for push-off during gait.
  • Absorbs high tensile forces.

⭐ The watershed area of the Achilles tendon, 2-6 cm proximal to its insertion, is prone to rupture due to relatively poor vascularity.

Achilles Tendinopathy - Wear & Tear Woes

Types:

• Overuse, training errors (↑ intensity/duration), poor footwear.
• Systemic: Fluoroquinolones, inflammatory arthropathies.
• Biomechanical: Pes planus/cavus, hindfoot malalignment, tight gastro-soleus.

Clinical Features:

• Activity-related pain, morning stiffness.
• Localized tenderness, palpable nodule/thickening.
• Painful arc sign (tender area moves with ankle motion).

Conservative Management (First-line):

• Activity modification, RICE. NSAIDs for pain.
• Eccentric loading exercises (Alfredson protocol) - cornerstone.
• Heel lifts/orthotics. ESWT for chronic cases.

⭐ The Alfredson protocol, involving eccentric heel-drop exercises, is a cornerstone of conservative management for Achilles tendinopathy.

Surgical Indications:

• Failure of >6 months comprehensive conservative Rx.
• Options: Debridement, +/- tendon transfer (e.g., FHL).

Management Flow:

Achilles Tendon Rupture - Snap, Crackle, Pop!

• Epidemiology: 'Weekend warriors', males 30-50 yrs; hx tendinopathy, fluoroquinolone/steroid use.

• Mechanism: Sudden eccentric load on dorsiflexed ankle; direct trauma.

• Clinical: Audible 'pop'/'snap', sudden severe posterior ankle pain, ↓ ability to push off, palpable gap.

• Diagnosis:

  • Thompson test (Simmonds' squeeze): No plantarflexion on calf squeeze (most reliable). 📌 'No Squeeze, No Flex'.
  • Matles test, O'Brien test (needle).

• Imaging:

  • Ultrasound: Confirms diagnosis, assesses gap (dynamic, cost-effective).
  • MRI: Chronic/missed cases, surgical planning.

• Management: Controversial. See table and flowchart below.

  Rx	Indications	Outcome Profile
  Conservative	Older, low-demand, comorbidities, gap <1 cm	Higher re-rupture; Lower complications
  Surgical	Active, athletes, larger gaps (>1 cm)	Lower re-rupture; Higher complications (infection, sural nerve injury)

⭐ A positive Thompson test (absence of passive plantarflexion on calf squeeze) is highly specific for a complete Achilles tendon rupture.

Associated Conditions & Imaging - The Full Picture

• Haglund's Deformity ('Pump Bump'):
  • Posterosuperior calcaneal prominence.
  • Assoc: Retrocalcaneal bursitis, insertional tendinopathy.
  • X-ray: Fowler-Philip angle >75°.
• Retrocalcaneal Bursitis:
  • Inflammation: Bursa between Achilles & calcaneus.
  • Pain anterior to tendon insertion.
• Sever's Disease (Calcaneal Apophysitis):
  • Traction apophysitis at Achilles insertion.
  • Age: 8-14 years (skeletally immature).
  • Activity-related heel pain, positive squeeze test.
• Paratenonitis:
  • Paratenon sheath inflammation; crepitus.

⭐ Haglund's deformity: prominent posterosuperior calcaneal tuberosity, often causes retrocalcaneal bursitis & insertional Achilles tendinopathy.

• Imaging Summary:
  • X-ray: Haglund's (Fowler-Philip angle >75°), calcifications, enthesophytes; Sever's (sclerosis/fragmentation).
  • USG: Tendon thickening/tears, neovascularization (Doppler), bursitis, paratenon fluid.
  • MRI: Gold standard for soft tissue; pre-op planning (complex cases).

High‑Yield Points - ⚡ Biggest Takeaways

• Achilles tendinopathy: Pain 2-6 cm proximal to insertion; Thompson test negative.
• Achilles rupture: Sudden "pop", positive Thompson test; common in "weekend warriors".
• Insertional tendinopathy: Pain at posterior heel insertion, often with Haglund's deformity.
• Key risk factors: Fluoroquinolones, corticosteroids, male sex, age >30.
• Diagnosis: Primarily clinical; Ultrasound confirms rupture or assesses tendinopathy.
• Tendinopathy treatment: Eccentric exercises are mainstay.
• Rupture treatment: Surgical repair (lower re-rupture) vs. conservative management (casting/bracing).