Courtesy: Lyndon Mason, FRCSOrth, Liverpool, UK

 

Achilles Tendon Rupture – Key Orthopaedic Principles

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Introduction

• The Achilles tendon is formed by:
  • Gastrocnemius
  • Soleus
  • (Together called triceps surae)

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Insertion

• Calcaneal tuberosity

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Fiber Orientation

• Tendon fibers rotate before insertion
• Medial gastrocnemius fibers insert more posteriorly

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Clinical Note

• Medial gastrocnemius release can improve tightness

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Blood Supply

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Segmental Supply

• Proximal – Posterior tibial artery
• Distal – Posterior tibial artery
• Mid-portion – Peroneal artery

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Key Point

• Mid-portion has:
  • Least vascularity
  • Most common rupture site

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Epidemiology

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• Incidence: 6–10 per 100,000
• ~75% occur during sports

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Demographics

• More common in:
  • Males
  • Middle-aged individuals

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“Weekend Warrior” Phenomenon

• Sedentary lifestyle + sudden intense activity

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Risk Factors

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Intrinsic

• Tendon degeneration
• Reduced vascularity
• Aging

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Extrinsic

• Overuse
• Sudden eccentric contraction
• Sudden increase in activity

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Medical Conditions

• Rheumatoid arthritis
• Gout
• Ankylosing spondylitis

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Medications

• Fluoroquinolones
• Phenytoin

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Pathophysiology

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• Most ruptures occur in:
  • Degenerated tendon

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Mechanism

• Strain > 8% elongation

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Typical Injury

• Eccentric loading of plantarflexed ankle

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Clinical Presentation

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Classic History

• “Hit at the back of the leg”
• Sudden pop or snap
• Immediate inability to continue activity

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Common Activities

• Football
• Running
• Dancing

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Clinical Examination

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Inspection

• Swelling
• Loss of tendon contour

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Palpation

• Possible palpable gap

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Special Test

Thompson Test (Simmonds Test)

• Patient prone – calf squeezed

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Interpretation

• Normal – plantarflexion
• Rupture – no plantarflexion

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Imaging

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X-ray

• May show:
  • Loss of Kager’s fat pad

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Ultrasound

• Useful but not always required

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MRI

• Indications:
  • Chronic rupture
  • Surgical planning

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Tendon Gap Concept

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• Earlier belief:
  • Gap >1 cm – poor outcome

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Current Understanding

• Tendon tears are:
  • Irregular (“seaweed tear”)

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Conclusion

• Gap measurement:
  • Not clinically reliable

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Healing Biology

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Early Phase

• Type I collagen – after 3 days

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First 2 Weeks

• Type III collagen predominates

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After 2 Weeks

• Collagen reorganizes longitudinally

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Definitions

• Acute rupture – <2 weeks
• Chronic rupture – >2 weeks

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Rehabilitation Principles

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• Controlled loading improves healing

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Problems with Immobilization

• Weak scar formation

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Benefits of Early Mobilization

• Better collagen alignment
• Stronger tendon

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Treatment

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1. Non-Operative (Preferred)

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Modern Functional Rehabilitation

• Functional boot
• Early mobilization
• Gradual weight bearing

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Outcomes

• Re-rupture rate:
  • <1%
• Comparable to surgery

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Orthotic Consideration

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• Boot must provide:
  • True equinus position

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Important

• Flat boots may:
  • Fail to shorten tendon properly

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2. Surgical Treatment

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Indications

• Failed conservative treatment
• Chronic rupture
• Insertional rupture
• Elite athletes (selected)
• Delayed diagnosis

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Complications (10–15%)

• Infection
• Wound problems
• Nerve injury
• Re-operation

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Minimally Invasive Surgery

• No clear functional advantage

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Deep Vein Thrombosis (DVT)

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• Highest risk among foot & ankle injuries

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Incidence

• Up to 50% (screened cases)

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Important

• Risk persists regardless of:
  • Treatment type
  • Weight bearing

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Return to Sport

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• Return rate:
  • 65–100%

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Time Frame

• 3–13 months

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Elite Athletes

• ~60% return

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Psychological Factors

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• Fear of re-rupture
• Fear of movement
• Lack of confidence

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Clinical Insight

• Psychological readiness affects recovery

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Chronic Achilles Tendon Rupture

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Definition

• Rupture >2–4 weeks

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Treatment Based on Gap

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Surgical Options

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1. V-Y Gastrocnemius Advancement

• For moderate defects

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2. Tendon Transfer

Common Choice

• Flexor hallucis longus (FHL)

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Advantages

• Strong plantarflexor
• Anatomically close
• Easy access

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3. Tendon Grafts

• Autograft
• Allograft (e.g., semitendinosus)

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Preferred Reconstruction Strategy

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• FHL transfer
• Resection of degenerated tendon
• Allograft reconstruction

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Benefits

• Restores tension
• Biological support
• Good functional outcome

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Key Takeaways

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• Common in middle-aged recreational athletes
• Diagnosis is clinical (Thompson test)
• Functional rehab often preferred over surgery
• Surgery has higher complication risk
• Chronic ruptures require reconstruction
• Psychological factors strongly influence outcomes