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  • Achilles tendinitis
  • Achilles tendonitis
  • Achilles paratenonitis

  • 726.71 Achilles bursitis or tendonitis

  • M76.60 Achilles tendinitis, unspecified leg


  • Insertional Achilles tendinitis: fibers in middle portion of the tendon breakdown, degenerate, swell, thicken
  • Noninsertional Achilles tendonitis: pain in lower portion of heel at tendon attachment
  • Pain common at midportion of Achilles tendon
  • Typically lacks presence of inflammatory cells, probably more tendonosis then tendonitis
  • Typically associated with tissue degeneration
    • Two types
      • Lipoid: fatty tissue deposited in the tendon
      • Mucoid: conversion of tendon in softer material with gray or brown appearance
    • Thickening of tendon
    • Neovascularization
    • Increased presence of varicose nerve fibers
      • Most likely source of pain

Essentials of Diagnosis

  • Patient history and clinical examination
  • Ultrasound or MRI imaging

General Considerations

  • Address training errors and biomechanics deficits to prevent recurrence


  • People participating in athletic activity; condition can also occur in sedentary individuals
    • Runners: 7 to 9% prevalence4
  • Age: between 30 to 50 years of age (median)4
  • Sex: Males more than females4
  • Onset more common during training vs. competitive event

Signs and Symptoms

  • Pain with palpation of tendon 2 to 6 cm proximal to the insertion
  • Pain back of the heel
  • Tenderness changes position with tendon movement during dorsiflexion and plantarflexion (arc sign)
  • Increased swelling throughout the day
  • Thickening of the tendon
  • Decreased dorsiflexion range of motion (ROM)
  • Decreased gastrocnemius strength
  • Greater pronation/calcaneal varus and faster rate of max. pronation
  • Decreased plantar flexion strength and endurance verse uninvolved side

Functional Implications

  • Inability to climb stairs or ladder
  • Inability to push-off during ambulation
  • Decreased stride length during ambulation

Possible Contributing Causes

  • Intrinsic risk factors
    • Decreased dorsiflexion ROM
    • Decreased gastrocnemius strength
    • Greater pronation/Calcaneal varus and faster rate of max. pronation
    • Comorbidities
    • Obesity
    • Diabetes
    • Hyperlipidemia
    • Hypertension
  • Extrinsic risk factors
    • Training errors
      • Sudden increase in mileage or intensity or incline
      • Return from inactivity
    • Environmental factors
      • High incidence with training in cold weather
    • Faulty equipment

Differential Diagnosis

  • Achilles tendon rupture
  • Achilles tendon partial tear
  • Bone spur
  • Sural nerve pathology
  • Retrocalcaneal bursitis
  • Posterior ankle impingement
  • Accessory soleus muscle
  • S1 radiculopathy
  • Achilles tendon ossification
  • Achilles enthesopathy
  • Os trigonum
  • Systemic inflammatory disease
  • Xanthoma of the tendon: accumulation of cholesterol in patients with familial hypercholesterolemia


  • Hypertrophic tendon
  • Hyperechoic mass at midtendon
  • Irregular tendon structure

  • Medication
    • NSAIDs
    • Prolotherapy: sclerosant injection (most common dextrose)

Medical Procedures

  • Tendon ...

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