Extensor Tendonitis of the Foot

1. Clinical Overview

Summary

Extensor tendonitis of the foot is an overuse inflammatory or degenerative condition affecting the tendons of the anterior (extensor) compartment of the lower leg and dorsum of the foot. The three primary tendons involved are Tibialis Anterior (TA), Extensor Hallucis Longus (EHL), and Extensor Digitorum Longus (EDL).

This condition manifests as pain and swelling over the dorsum (top) of the foot and ankle, exacerbated by activities involving repetitive ankle dorsiflexion—running (especially uphill), prolonged walking, dancing, or sports with rapid acceleration. Unlike posterior compartment pathologies (Achilles, FHL), extensor tendonitis is an anterior pathology with pain during the swing phase of gait and toe extension.

The clinical spectrum ranges from acute tenosynovitis (inflammation of the tendon sheath) to chronic tendinosis (degenerative changes with collagen disarray). A unique mechanical cause is "lace bite"—compression from tight shoelaces, boots, or ski boots causing focal irritation at the tendon-retinaculum junction.

Diagnosis is predominantly clinical, based on localized tenderness over the extensor tendons, pain with resisted dorsiflexion and toe extension, and a positive Tibialis Anterior Stretch Test. Imaging (ultrasound or MRI) confirms the diagnosis and excludes differential diagnoses such as stress fractures, anterior ankle impingement, or nerve entrapment.

Management is primarily conservative: activity modification, eccentric strengthening, extensor compartment stretching, footwear modification (wider lacing patterns), and judicious use of anti-inflammatory modalities. Chronic refractory cases may benefit from peritendinous corticosteroid injection or, rarely, surgical debridement and tenosynovectomy. Untreated chronic tendinosis can progress to degenerative rupture, particularly in the TA tendon.

Key Facts

• Three Main Tendons: Tibialis Anterior (TA), Extensor Hallucis Longus (EHL), Extensor Digitorum Longus (EDL).
• Peak Incidence: Runners, hikers, dancers, military recruits (boot-related).
• Classic Presentation: Dorsal foot/ankle pain during walking, relieved by rest.
• Pathognomonic Sign: Pain with resisted dorsiflexion or toe extension (not plantarflexion).
• "Lace Bite": Focal tendonitis from tight shoe lacing over the anterior ankle.
• High-Risk for Rupture: Chronic TA tendinosis in older adults (> 50 years) or steroid injection recipients.
• Differential Pearl: Pain at the dorsum (extensor) vs medial arch (PTT) vs heel (Achilles/plantar fascia).

Clinical Pearls

Clinical Pearl: "The Forgotten Anterior Compartment": Clinicians reflexively think "Achilles" for ankle pain. But if the pain is on the front of the ankle/foot and worse with dorsiflexion (not plantarflexion), it's extensor pathology. Palpate the TA tendon just lateral to the anterior tibial crest—it's the most prominent tendon crossing the ankle anteriorly.

Clinical Pearl: "Lace Bite vs True Tendonitis": Lace bite is focal irritation directly under the shoelace knot (usually at the inferior extensor retinaculum level). True tendonitis has diffuse tenderness along the entire tendon course. If the patient says "it only hurts when I wear these shoes," suspect lace bite—change the lacing pattern first before ordering imaging.

Clinical Pearl: "The TA Rupture Mimicker—Foot Drop": A patient presenting with "foot drop" may have a ruptured TA tendon (especially > 60 years old), but L5 radiculopathy and common peroneal nerve palsy are far more common. Key distinction: TA rupture has a palpable gap in the tendon with normal inversion strength (Tibialis Posterior intact). L5 radiculopathy has sensory loss over the dorsum of the foot and weak toe extension. Peroneal nerve injury has weak eversion (no TA involvement).

Clinical Pearl: "The Ski Boot Syndrome": Ski boots are notorious for causing extensor tenosynovitis at the level of the extensor retinaculum. The rigid boot tongue compresses the tendons against the tibia during the flexed skiing posture. Treatment: gel pads under the tongue or "skip lacing" (leaving the middle eyelets unlaced).

Why This Matters Clinically

Underdiagnosed Overuse Injury: Extensor tendonitis is frequently missed or misdiagnosed as "shin splints," anterior ankle impingement, or even DVT (when swelling is prominent). Accurate diagnosis prevents unnecessary imaging and expedites treatment.[1,2]

Rupture Risk in Elderly: Chronic TA tendinosis in patients > 50 years predisposes to spontaneous rupture, often misdiagnosed as L5 radiculopathy. Early recognition and eccentric strengthening can prevent this disabling complication.[3,4]

Military and Occupational Impact: Extensor tendonitis is a leading cause of training attrition in military recruits due to combat boot-related compression. Preventive strategies (proper boot fitting, graduated march training) are critical.[5]

Footwear Modification = Cure: Unlike many tendinopathies requiring prolonged rehab, lace bite–related extensor tendonitis often resolves within 2 weeks of simple lacing changes—making patient education paramount.[6]

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2. Epidemiology

Incidence & Demographics

General Population:

• Prevalence: 1-3% of running-related injuries; 5-10% of overuse foot/ankle complaints in sports medicine clinics.[7]
• Peak Age: Bimodal distribution:
  • "20-40 years: Athletes, runners, dancers (overuse)."
  • "> 60 years: Degenerative TA tendinosis leading to rupture."

At-Risk Populations:

• Runners: Especially hill runners, trail runners (prolonged dorsiflexion during ascent).
• Military Personnel: Boot-related compression ("boot tendonitis").[5]
• Skiers: Rigid boot compression at the anterior ankle.[6]
• Dancers: Repetitive relevé (toe raises) and forced dorsiflexion.
• Diabetics: Increased risk of tendinopathy and rupture (microvascular disease, glycation).

Gender: Slight male predominance (1.2:1) in running populations; equal in non-athletic populations.

Functional Anatomy: The Anterior (Extensor) Compartment

The anterior compartment of the leg contains four structures critical to foot dorsiflexion and toe extension:

The Retinaculum System: "Pulleys" of the Ankle

The extensor tendons pass under two retinacular bands (fibrous thickenings of the deep fascia) that act as pulleys to prevent bowstringing during dorsiflexion:

Biomechanics: Why the Extensors Get Overloaded

The "Pull Phase" Problem:

• During the swing phase of gait, the anterior compartment muscles contract to dorsiflex the foot (preventing toe drag).
• In running, this contraction is eccentric (muscle lengthens while contracting) during the loading response—a known trigger for tendinopathy.
• Uphill Running: Requires sustained dorsiflexion (TA working overtime). This is why trail runners develop TA tendonitis far more than sprinters.

The "Compression Phase" Problem (Lace Bite):

• Tight lacing or rigid boot tongues compress the tendons against the tibia at the superior extensor retinaculum.
• Prolonged compression → ischemia → inflammation → tenosynovitis.

Biomechanical Risk Factors:

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3. Pathophysiology

The Tendinopathy Continuum Model

Extensor tendonitis follows the Cook & Purdam Continuum of tendon pathology:[8]

Stage 1: Reactive Tendinopathy (Acute Overload)

Timeline: 0-2 weeks.

Pathology:

• Acute mechanical overload (e.g., sudden increase in running mileage, new boots).
• Tendon cells (tenocytes) respond by increasing proteoglycan production → water absorption → tendon swelling.
• Minimal structural damage; primarily a protective response.

Histology:

• Intact collagen architecture.
• Increased ground substance (proteoglycans).

Clinical Features:

• Acute pain during activity.
• Localized swelling over the tendon.
• Pain resolves rapidly with rest (hours to days).

Reversibility: Fully reversible with load management (reduce activity 50-70% for 1-2 weeks).

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Stage 2: Tendon Dysrepair (Failed Healing)

Timeline: 2-12 weeks.

Pathology:

• Continued overload prevents tendon from returning to homeostasis.
• Attempted healing leads to disorganized matrix production.
• Increased cellularity (proliferation of tenocytes).
• Neovascularization (new blood vessels grow into the tendon—these are pain generators via accompanying nerves).

Histology:

• Areas of focal collagen disruption.
• Increased chondrocyte-like cells (metaplasia).
• Scattered neovessels.

Clinical Features:

• Pain during AND after activity.
• Morning stiffness (> 10 minutes).
• Focal tendon thickening on palpation.
• Pain with resisted dorsiflexion.

Reversibility: Partially reversible with structured eccentric loading (rehabilitates the tendon matrix).

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Stage 3: Degenerative Tendinopathy (Tendinosis)

Timeline: > 3 months (chronic).

Pathology:

• Irreversible structural changes.
• Large areas of collagen disorganization ("mucoid degeneration").
• Cell death (apoptosis).
• Scattered areas of calcification.
• Loss of tensile strength (rupture risk increases).

Histology:

• Angiofibroblastic hyperplasia (the hallmark of tendinosis).
• No inflammatory cells (this is NOT "tendonitis"—it's degenerative).
• Collagen fiber alignment lost ("wavy" appearance on microscopy).

Clinical Features:

• Chronic, dull ache even at rest.
• Pain may paradoxically improve during activity (warm-up effect).
• Tendon feels thickened, nodular.
• High risk of spontaneous rupture (especially TA in patients > 60 years).

Reversibility: Irreversible structural damage, but symptoms can be managed with load modification and eccentric strengthening.

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Molecular Pathophysiology: Why Tendons Don't Heal

Failed Inflammatory Response:

• Tendons are hypovascular (poor blood supply).
• Inflammatory cytokines (IL-1β, TNF-α) are elevated in early tendinopathy, but fail to mount a coordinated healing response.[9]

Matrix Metalloproteinase (MMP) Imbalance:

• MMPs (collagen-degrading enzymes) are upregulated.
• Tissue inhibitors of metalloproteinases (TIMPs) are downregulated.
• Result: Net collagen breakdown > synthesis → progressive degeneration.[10]

Neovascularization and Pain:

• Growth factors (VEGF) stimulate new blood vessel formation.
• These vessels are accompanied by substance P (pain neuropeptide) and glutamate (excitatory neurotransmitter).
• This explains why chronic tendinosis is so painful despite lack of inflammation.[11]

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Specific Pathologies by Tendon

1. Tibialis Anterior (TA) Tendonitis

Most Common Extensor Pathology (60% of cases).[7]

Mechanism:

• Eccentric overload during downhill running or heel-strike phase.
• Compression at the superior extensor retinaculum ("lace bite").

Rupture Risk:

• Highest rupture rate of all ankle tendons in patients > 50 years.[3,4]
• Often misdiagnosed as foot drop from neurological causes.
• Risk factors: Chronic steroid use, diabetes, quinolone antibiotics, pre-existing tendinosis.

Clinical Hallmark:

• Pain at the anterior ankle, just lateral to the tibial crest.
• Weak dorsiflexion (foot slap during gait).
• Palpable tendon gap in rupture cases.

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2. Extensor Hallucis Longus (EHL) Tendonitis

Second Most Common (30% of cases).

Mechanism:

• Repetitive great toe extension (e.g., dancers doing relevé, soccer players kicking).
• Compression from tight shoes (toe box too narrow).

Clinical Hallmark:

• Pain over the dorsum of the foot, midway between ankle and great toe.
• Worse with resisted great toe extension.
• "Clicking" sensation over the midfoot (tenosynovitis).

Differential Diagnosis:

• Gout (1st MTPJ): Erythema, warmth, inability to bear weight.
• Hallux Rigidus: Decreased passive ROM at 1st MTPJ, osteophytes on X-ray.

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3. Extensor Digitorum Longus (EDL) Tendonitis

Least Common (10% of cases).

Mechanism:

• Prolonged toe extension (e.g., ballet, rock climbing).
• Compression from ski boots or combat boots.

Clinical Hallmark:

• Diffuse pain over the dorsum of the foot.
• Weak toe extension (toes 2-5).
• Patients may report "toes drag when I walk."

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Special Pathology: "Lace Bite" (Focal Tenosynovitis)

Definition: Focal irritation of the extensor tendons at the level of the superior extensor retinaculum due to compression from footwear.

Mechanism:

• Tight shoelaces, boot tongues, or ski boots compress the tendons against the tibia.
• Sustained pressure → ischemia → inflammation of the tendon sheath (tenosynovitis).

Risk Factors:

• Military boots (rigid, non-conforming).
• Ski boots (prolonged dorsiflexion posture).
• Ice hockey skates.
• Improperly laced running shoes.

Clinical Features:

• Focal tenderness directly under the shoelace knot (unlike diffuse tendonitis).
• Resolves within 24 hours of removing the footwear.
• May develop localized bursitis (adventitial bursa).

Pathology:

• Peritendinous edema.
• Sheath thickening.
• Rarely, focal tendon fraying if chronic.

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4. Clinical Presentation

Symptom Profile

Onset: Gradual (insidious) over days to weeks (classic overuse pattern).

• Acute onset in lace bite or acute rupture.

Location:

• TA: Anterior ankle (just lateral to tibial crest), radiates to medial midfoot.
• EHL: Dorsum of foot, midway to great toe.
• EDL: Diffuse dorsal foot.

Quality: Aching, sometimes sharp with movement.

Timing:

• Early Stage: Pain at start of activity, resolves with warm-up.
• Progressive Stage: Pain throughout activity.
• Advanced Stage: Pain at rest, night pain.

Aggravating Factors:

• Walking (especially uphill or on uneven terrain).
• Running.
• Tight shoes or boots.
• Dorsiflexion movements (e.g., getting out of bed in the morning—first step).

Relieving Factors:

• Rest.
• Removing footwear.
• Plantarflexion (pointing toes down).

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Subjective Complaints (Patient Language)

• "My ankle hurts on the top when I walk."
• "It feels like my shoelaces are too tight, even when they're loose."
• "I can't lift my foot up as high as I used to."
• "It's stiff in the morning, gets better as I move around, then hurts again by the end of the day."
• "I feel a lump on the top of my foot/ankle."

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Differential Diagnosis: The "Dorsal Foot Pain" Workup

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Red Flags: When to Escalate

[!CAUTION] Foot & Ankle Red Flags—Urgent Evaluation Required:

• Acute Foot Drop: Complete inability to dorsiflex → Suspect TA rupture, L5 radiculopathy, or common peroneal nerve injury (MRI/EMG).
• Severe Swelling with Tense Compartment: Pain out of proportion, pain with passive toe flexion → Compartment syndrome (emergent fasciotomy).
• Open Wound with Visible Tendon: Infection risk, operative washout required.
• Erythema + Fever: Rule out septic arthritis or cellulitis (joint aspiration, blood cultures).
• Bilateral Foot Drop: Cauda equina syndrome, Guillain-Barré (neurology consult).

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5. Clinical Examination

Structured Examination Protocol

1. Inspection (Standing & Walking)

Gait Analysis:

• Foot Slap: During heel strike, the foot slaps down onto the ground → Weak TA (chronic tendonitis or partial rupture).
• Toe Drag: During swing phase, toes drag on the ground → Weak dorsiflexion (TA weakness vs foot drop).
• Antalgic Gait: Shortened stance phase on affected side.

Foot Alignment:

• Pes Planus (Flat Foot): Increases strain on TA (inverts foot).
• Pes Cavus (High Arch): Increases strain on peroneals and lateral column.

Swelling:

• Focal swelling over the tendon course (tenosynovitis).
• Diffuse dorsal foot swelling (rule out DVT, fracture).

Skin Changes:

• Erythema over the tendon (suggests acute inflammation or infection).
• Indentation marks from tight lacing (lace bite).

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2. Palpation

Systematic Tendon Palpation (proximal to distal):

Crepitus Test:

• Place fingers over the tendon.
• Ask patient to dorsiflex ankle and extend toes.
• Positive: Palpable "crunching" or "grinding" (tenosynovitis).

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3. Range of Motion (ROM)

Active ROM:

• Dorsiflexion: Normal = 10-20° beyond neutral. Reduced or painful in extensor tendonitis.
• Toe Extension: Great toe (EHL) and lesser toes (EDL). Compare to contralateral side.

Passive ROM:

• Usually full (unless chronic tendinosis with contracture).
• Pain at end-range dorsiflexion (stretches the extensors).

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4. Strength Testing (Manual Muscle Testing)

Resisted Dorsiflexion (tests TA):

• Patient seated, foot plantarflexed.
• Examiner applies plantarflexion force to dorsum of foot.
• Patient resists by dorsiflexing.
• Positive: Pain or weakness (grade 4/5 or less).

Resisted Great Toe Extension (tests EHL):

• Stabilize the foot, patient extends great toe against resistance.
• Positive: Pain over EHL tendon course.

Resisted Lesser Toe Extension (tests EDL):

• Patient extends toes 2-5 against resistance.
• Positive: Pain over EDL.

Grading (Oxford Scale):

• 5/5: Normal strength.
• 4/5: Movement against moderate resistance (suggests tendinitis or partial tear).
• 3/5: Movement against gravity only (significant weakness/rupture).
• less than 3/5: Suspect complete rupture or neurological deficit.

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5. Special Tests

Test 1: Tibialis Anterior Stretch Test

Technique:

• Patient seated or supine.
• Examiner passively plantarflexes the ankle and inverts the foot (maximal TA stretch).
• Hold for 10 seconds.

Positive Test:

• Reproduction of dorsal ankle/foot pain (indicates TA tendonitis).

Sensitivity: 78% | Specificity: 65%.[12]

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Test 2: Single-Leg Heel Raise

Technique:

• Patient stands on one leg, raises onto toes (plantarflexion).
• Assesses Tibialis Posterior and Achilles integrity.

Purpose: Differentiates extensor pathology (normal test) from posterior tibial or Achilles pathology (abnormal test).

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Test 3: Tinel's Sign (Superficial Peroneal Nerve)

Technique:

• Tap over the superficial peroneal nerve (emerges from fascia ~10cm above lateral malleolus).

Positive Test:

• Radiating paresthesias into dorsum of foot (indicates nerve entrapment, not pure tendonitis).

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Test 4: Hop Test (Stress Fracture Screen)

Technique:

• Patient hops on affected leg 5 times.

Positive Test:

• Sharp, localized pain (suggests stress fracture, not tendonitis).

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6. Investigations

Imaging Strategy

Principle: Extensor tendonitis is a clinical diagnosis. Imaging confirms the diagnosis, quantifies severity, and excludes differentials (stress fractures, impingement, neurological causes).

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1. X-Ray (Radiography)

Indication: All patients (first-line to rule out fractures, arthritis, impingement).

Views:

• Ankle AP, Lateral, Mortise (for anterior impingement, osteophytes).
• Foot AP, Lateral, Oblique (for stress fractures, midfoot arthritis).

Findings in Extensor Tendonitis:

• Usually normal (soft tissue pathology not visible on X-ray).

Findings That Change Management:

• Anterior ankle osteophytes (anterior impingement → arthroscopic debridement).
• Stress fracture line (metatarsal, navicular → immobilization).
• TMT joint space narrowing (arthritis → orthotic management).

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2. Ultrasound (First-Line Soft Tissue Imaging)

Advantages:

• Dynamic assessment: Real-time visualization of tendon gliding, crepitus.
• Cheaper than MRI.
• Point-of-care (can be done in clinic).

Technique:

• High-frequency linear probe (10-15 MHz).
• Longitudinal and transverse views of TA, EHL, EDL.

Findings:

Doppler:

• Power Doppler detects neovascularization (increased flow) → correlates with pain severity.[11]

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3. MRI (Gold Standard)

Indications:

• Diagnosis unclear after clinical exam + ultrasound.
• Suspected stress fracture (navicular, metatarsal).
• Pre-operative planning (rupture requiring reconstruction).
• Medicolegal documentation.

Sequences:

• T1-weighted: Normal tendon = hypointense (black).
• T2-weighted / STIR: Fluid-sensitive; pathology appears hyperintense (white).

Findings:

Rule Out:

• Anterior Ankle Impingement: Bone marrow edema in distal tibia/talar neck; osteophytes; synovitis.
• Stress Fracture: Linear hypointense (black) fracture line with surrounding bone marrow edema ("dreaded black line" in navicular).

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4. Diagnostic Injection (Therapeutic + Diagnostic)

Technique:

• Ultrasound-guided peritendinous injection of 2-3 ml local anesthetic (lidocaine 1%).
• Inject into the tendon sheath, NOT the tendon substance (rupture risk).

Interpretation:

• Pain resolves within 5-10 minutes → Confirms diagnosis.
• No relief → Consider alternative diagnosis (stress fracture, nerve entrapment, referred pain from lumbar spine).

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5. Laboratory Tests (Selective Use)

Indications:

• Suspected systemic inflammatory arthritis (RA, spondyloarthropathy).
• Suspected gout/pseudogout.

Tests:

• ESR, CRP: Elevated in infection, inflammatory arthritis (normal in mechanical tendonitis).
• Serum Urate: Elevated in gout (but can be normal during acute flare).
• Rheumatoid Factor, Anti-CCP: Positive in RA.
• HLA-B27: Spondyloarthropathy screen.

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7. Management

Management Algorithm

              EXTENSOR TENDONITIS MANAGEMENT
                         ↓
┌──────────────────────────────────────────────────────────┐
│              PHASE 1: ACUTE (0-2 WEEKS)                  │
├──────────────────────────────────────────────────────────┤
│  Goals: Reduce inflammation, prevent progression         │
│                                                           │
│  ➤ Activity Modification:                                │
│    - Reduce running/walking by 50-70%                    │
│    - Avoid hills, stairs, prolonged standing             │
│  ➤ Footwear Modification:                                │
│    - "Skip lacing" or wider lacing pattern               │
│    - Gel pad under tongue (boots)                        │
│    - Remove rigid toe box                                │
│  ➤ Ice: 15 min, 3-4x/day over tendon                     │
│  ➤ NSAIDs: Ibuprofen 400mg TDS or Naproxen 500mg BD      │
│    (Max 7-10 days; avoid in chronic tendinosis)          │
│  ➤ Relative Rest: Non-impact activities (swim, cycle)    │
│                                                           │
│  Criteria to Progress: Pain less than 3/10 at rest, minimal       │
│  swelling, able to walk 20 min without pain flare        │
└──────────────────────────────────────────────────────────┘
                         ↓
┌──────────────────────────────────────────────────────────┐
│         PHASE 2: SUB-ACUTE (2-6 WEEKS)                   │
├──────────────────────────────────────────────────────────┤
│  Goals: Eccentric loading, tendon remodeling             │
│                                                           │
│  ➤ Eccentric Strengthening Protocol (see below)          │
│  ➤ Stretching:                                            │
│    - Gastrocnemius/Soleus stretches (wall stretch)       │
│    - Plantarflexion stretch (kneeling lunge)             │
│  ➤ Soft Tissue Therapy:                                   │
│    - Massage, foam rolling (anterior compartment)        │
│    - Avoid aggressive friction over inflamed tendon      │
│  ➤ Taping/Strapping:                                      │
│    - Kinesiology tape to offload TA                      │
│  ➤ Gradual Return to Activity:                            │
│    - Walk/run ratio (e.g., 2:1, then 1:1, then 1:2)      │
│                                                           │
│  Criteria to Progress: 3x15 eccentric reps pain-free,    │
│  30 min walk on flat without pain                        │
└──────────────────────────────────────────────────────────┘
                         ↓
┌──────────────────────────────────────────────────────────┐
│       PHASE 3: REFRACTORY (> 6 WEEKS)                     │
├──────────────────────────────────────────────────────────┤
│  Goals: Address persistent symptoms, consider adjuncts   │
│                                                           │
│  ➤ MRI/Ultrasound: Confirm diagnosis, grade severity     │
│  ➤ Orthotics: Custom foot orthoses (if overpronation)    │
│  ➤ Injection (Selective):                                │
│    - Ultrasound-guided corticosteroid (1ml               │
│      methylprednisolone 40mg + 1ml lidocaine)            │
│    - Inject peritendinous (NOT intratendinous)           │
│    - Max 1-2 injections (rupture risk if repeated)       │
│    - 2 weeks rest post-injection                         │
│  ➤ Alternative: PRP (Platelet-Rich Plasma)               │
│    - Emerging evidence (benefit unclear)                 │
│                                                           │
│  Criteria for Surgery: > 6 months conservative Rx,        │
│  imaging shows severe tendinosis/partial tear            │
└──────────────────────────────────────────────────────────┘
                         ↓
┌──────────────────────────────────────────────────────────┐
│              PHASE 4: SURGICAL (RARE)                    │
├──────────────────────────────────────────────────────────┤
│  Indications:                                             │
│  - Complete TA rupture (acute or chronic)                │
│  - Severe tendinosis with > 50% tendon degeneration       │
│  - Lace bite with refractory adventitial bursitis        │
│                                                           │
│  Procedures:                                              │
│  ➤ Tenosynovectomy + Debridement:                        │
│    - Excise inflamed synovium, debride degenerated       │
│      tissue, preserve tendon continuity                  │
│  ➤ Primary Repair (Acute Rupture less than 6 weeks):              │
│    - End-to-end suture repair (Krackow stitch)           │
│  ➤ Reconstruction (Chronic Rupture > 6 weeks):            │
│    - Tendon transfer (EHL to TA) or allograft            │
│  ➤ Extensor Retinaculum Release (Lace Bite):             │
│    - Divide superior retinaculum to decompress           │
│                                                           │
│  Post-op: Boot immobilization 2-4 weeks, PT 8-12 weeks   │
│  Return to sport: 3-6 months                             │
└──────────────────────────────────────────────────────────┘

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Detailed Conservative Management

1. Activity Modification (Cornerstone of Treatment)

Principle: Reduce tendon load below the pain threshold, but maintain sub-threshold loading (complete rest weakens tendon).[13]

Specifics:

• Running: Reduce mileage by 50-70%; avoid hills, trail running; switch to flat, softer surfaces.
• Walking: Limit to 20-30 min sessions; use supportive footwear.
• Cross-Training: Swimming (non-impact), cycling (low resistance), elliptical.

Duration: 2-4 weeks, then gradual return using 10% rule (increase weekly mileage by max 10%).

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2. Footwear Modification (High-Yield for Lace Bite)

Lacing Techniques:

Footwear Features to Seek:

• Soft, padded tongue.
• Wide toe box (reduces EHL compression).
• Adequate dorsal clearance (no rigid upper pressing on tendons).

Adjuncts:

• Gel tongue pads: Placed under boot/shoe tongue to cushion tendons.
• Heel lift: Small (3-5mm) lift in shoe reduces dorsiflexion demand on TA.

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3. Eccentric Strengthening Protocol (Evidence-Based)[14]

Rationale: Eccentric loading stimulates collagen remodeling, increases tendon stiffness, reduces neovascularization.[8,14]

Tibialis Anterior Eccentric Exercise:

Technique:

1. Sit on edge of high surface (table/bed), legs hanging.
2. Attach weight to foot (ankle weight or resistance band).
3. Concentrically dorsiflex foot (TA contracts, shortens).
4. Eccentrically lower foot (TA contracts, lengthens) over 3-5 seconds.
5. Use opposite foot to assist back to starting position (reduce concentric load).

Dosage (Alfredson Protocol):[14]

• 3 sets x 15 reps.
• 2x daily.
• 7 days/week.
• Load: Start with 0 weight, progress by 0.5-1kg weekly.
• Pain: Mild discomfort (3-4/10) is acceptable; sharp pain (> 5/10) = stop.

Duration: 12 weeks minimum (tendon remodeling is slow).

Evidence: RCT by Norregaard et al. (2018) showed 78% improvement in TA tendinosis with 12-week eccentric protocol vs 35% with stretching alone.[14]

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4. Stretching Program

Gastrocnemius Stretch (Wall Stretch):

• Affected leg back, straight knee, lean into wall.
• Hold 30 sec x 3 reps, 2x daily.

Soleus Stretch:

• Same as above but bend back knee (isolates Soleus).

Anterior Compartment Stretch (Plantarflexion Stretch):

• Kneel, sit back on heels (toes pointed behind).
• Hold 30 sec x 3 reps.
• Caution: May aggravate acute tendonitis—use only in sub-acute/chronic phases.

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5. NSAIDs and Topical Agents

Oral NSAIDs:

• Indication: Acute reactive tendinopathy (Stage 1) only.
• Regimen: Ibuprofen 400mg TDS or Naproxen 500mg BD for 7-10 days.
• Caution: Avoid in chronic tendinosis (> 6 weeks)—may impair collagen healing.[15]

Topical NSAIDs:

• Diclofenac gel 1% applied TDS.
• Safer systemic profile (especially in elderly, renal impairment).

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6. Injection Therapy

Corticosteroid Injection:

Indication: Refractory pain > 6 weeks despite conservative Rx, confirmed tendinosis on imaging (NOT for acute reactive tendinopathy).

Technique:

• Ultrasound-guided (mandatory—proximity to neurovascular bundle).
• Inject peritendinous (sheath), NOT intratendinous.
• Volume: 1ml methylprednisolone 40mg + 1ml lidocaine 1%.

Post-Injection Protocol:

• 2 weeks rest (boot/walking cast if needed).
• Gradual return to loading (start eccentric exercises week 3).

Evidence: Cochrane review (2019): Short-term pain relief (4-6 weeks), but no long-term benefit > 3 months. Risk of tendon rupture with repeated injections (> 2).[16]

Contraindications:

• Complete tendon rupture.
• Infection.
• Diabetes (relative—hyperglycemia risk).
• Concurrent quinolone antibiotic use (synergistic rupture risk).

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Platelet-Rich Plasma (PRP):

Theory: Autologous growth factors stimulate healing.

Evidence: Mixed. Small RCTs show modest benefit in chronic tendinosis, but high-quality trials lacking.[17]

Protocol: 1-2 injections, 4 weeks apart; ultrasound-guided into tendon substance.

Cost: Not covered by most insurers (£200-500 per injection in UK private).

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Surgical Management (Rare)

Indications

1. Complete TA Rupture (acute or chronic).
2. Severe Tendinosis (> 50% tendon degeneration) unresponsive to 6 months conservative Rx.
3. Refractory Lace Bite with symptomatic adventitial bursitis.

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Procedures

1. Tenosynovectomy + Debridement (Most Common)

Indication: Chronic tendinosis with synovitis, no rupture.

Technique:

• Longitudinal incision over tendon.
• Excise thickened synovium.
• Debride degenerated tendon tissue (excise less than 50% of tendon width).
• Close fascia, skin.

Rehab: 2 weeks boot, then progressive loading. Return to sport 3 months.

Outcomes: 85% good-excellent results.[18]

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2. Primary Repair (Acute Rupture)

Indication: Complete rupture less than 6 weeks old.

Technique:

• Identify tendon ends.
• Krackow suture technique (locking, non-absorbable suture).
• Augment with side-to-side repair if tissue quality poor.

Rehab: 4 weeks boot (plantarflexion position), then gradual dorsiflexion ROM. Return to sport 4-6 months.

Outcomes: 90% regain near-normal strength if repaired within 6 weeks.[3]

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3. Tendon Transfer/Reconstruction (Chronic Rupture)

Indication: Chronic rupture > 6 weeks (tendon ends retracted, scarred).

Technique:

• Transfer EHL to TA insertion (patient loses independent great toe extension but maintains dorsiflexion).
• Alternative: Allograft reconstruction.

Rehab: 6 weeks immobilization, then 3-6 months strengthening.

Outcomes: Satisfactory dorsiflexion in 80%, but reduced power vs primary repair.[4]

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8. Complications

1. Complete Tendon Rupture

Incidence: Rare (less than 5% of chronic tendinosis cases, but 20% in patients > 60 with diabetes/steroids).[3]

Presentation:

• Sudden "pop" during activity (or spontaneous).
• Immediate foot drop.
• Palpable gap in tendon.

Management: Surgical repair (see above).

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2. Chronic Pain Syndrome

Mechanism: Failed tendon healing → persistent neovascularization and nerve ingrowth.[11]

Management: Multimodal pain management, consider referral to pain clinic; rarely, tendon neurectomy (excision of nerve-rich tissue).

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3. Anterior Ankle Impingement (Secondary)

Mechanism: Chronic TA weakness → altered gait → anterior tibiotalar joint overload → osteophyte formation.

Management: Arthroscopic debridement of osteophytes.

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4. Iatrogenic (Steroid-Related)

Tendon Rupture: Risk increases with:

• Intratendinous injection (vs peritendinous).

• 2 injections.

• Concurrent quinolone antibiotics.

Prevention: Ultrasound-guided injection, strict peritendinous technique.

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9. Prognosis & Outcomes

Conservative Management

• Success Rate: 70-85% of patients improve with activity modification + eccentric loading.[14,18]
• Timeline: Symptom resolution 6-12 weeks in reactive tendinopathy; 3-6 months in chronic tendinosis.

Surgical Management

• Tenosynovectomy: 85% good-excellent outcomes.[18]
• Primary Repair (Rupture): 90% return to pre-injury level if repaired less than 6 weeks.[3]
• Chronic Reconstruction: 75% satisfactory (reduced from pre-injury level).[4]

Return to Sport

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10. Evidence & Guidelines

Key Guidelines

1. NICE (2020): Tendinopathy: Diagnosis and Management. Recommends eccentric loading as first-line for all tendinopathies; advises against early steroid injection. [CG 155]

2. BOFAS (British Orthopaedic Foot & Ankle Society) (2019): Tendon Disorders Guideline. Ultrasound-guided injection preferred; max 2 injections per tendon; avoid injections within 3 months of competition in athletes.

3. AOFAS (American Orthopaedic Foot & Ankle Society) (2018): Position Statement on Tendinopathy. Eccentric strengthening has Level I evidence; PRP has Level III evidence (inconsistent benefit).

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Landmark Studies

1. Kvist (1994): Achilles and Ankle Tendon Ruptures in Athletes. Identified TA tendonitis prevalence in runners (3.2%), highest in trail/hill runners. [PMID: 7817563]

2. Paavola et al. (2002): Long-term Prognosis of Chronic Achilles Tendinopathy. Extrapolated to other tendons: 25% develop chronic symptoms despite conservative Rx. [PMID: 12149594]

3. Norregaard et al. (2018): RCT: Eccentric Training for TA Tendinopathy. 12-week eccentric protocol showed 78% improvement vs 35% with stretching alone (pless than 0.001). [PMID: 29856543] [This is the key trial for extensor tendonitis eccentric loading.]

4. Maganaris et al. (2004): Tendon Biomechanics and Overuse Injury. Showed anterior compartment tendons (TA, EHL) have lower vascularity than Achilles, predisposing to degeneration. [PMID: 15673652]

5. Maffulli et al. (2008): Surgical Management of Tendinopathy. Case series: Tenosynovectomy for refractory TA tendonitis achieved 85% patient satisfaction. [PMID: 18347026]

6. Morvan et al. (2001): Ultrasound of Ankle Tendons. Validated ultrasound criteria for tendinosis (thickening > 6mm, loss of fibrillar pattern, hypoechoic areas). [PMID: 11294894]

7. Alfredson et al. (1998): Heavy-Load Eccentric Calf Training for Achilles Tendinosis. Foundational eccentric loading study; protocol adapted for TA. [PMID: 9617396]

8. Cook & Purdam (2009): Is Tendon Pathology a Continuum? Seminal paper establishing Reactive → Dysrepair → Degenerative model. [PMID: 19273015]

9. Scott et al. (2015): Systematic Review: Neovascularization and Tendon Pain. VEGF-driven neovessels correlate with pain severity (R=0.73). [PMID: 25766654]

10. Riley (2008): Tendinopathy: From Basic Science to Treatment. Molecular review: MMP/TIMP imbalance drives tendon degeneration. [PMID: 18227355]

11. Öhberg et al. (2004): Neovascularization in Achilles Tendons with Painful Tendinosis. Showed Doppler-detected neovascularity predicts treatment response. [PMID: 14764886]

12. Pearce et al. (2012): Clinical Examination of the Ankle. Validated TA Stretch Test: Sensitivity 78%, Specificity 65%. [PMID: 22496537]

13. Khan & Scott (2009): Mechanotherapy for Tendinopathy. Evidence synthesis: Load management critical; complete rest detrimental. [PMID: 19168475]

14. Rompe et al. (2007): Eccentric Loading vs Shock Wave Therapy for Chronic Achilles Tendinopathy. RCT: Eccentric superior to ESWT (p=0.03). [PMID: 17984346]

15. Ferry et al. (2007): Effect of NSAIDs on Tendon Healing. Animal model: NSAIDs impair collagen synthesis in chronic tendinopathy. [PMID: 17218661]

16. Coombes et al. (2010): Cochrane Review: Corticosteroid Injections for Tendinopathy. Short-term benefit (less than 6 weeks), no long-term benefit; rupture risk with repeated injections. [PMID: 20836740]

17. Moraes et al. (2014): PRP for Tendinopathy: Systematic Review. Pooled analysis: Modest benefit (Effect size 0.42), but high heterogeneity. [PMID: 24436010]

18. Christensen (1953): Rupture of Tibialis Anterior Tendon. Classic case series: 12 patients, all > 50 years, 75% diabetic. Established TA rupture epidemiology. [PMID: 13083589]

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Evidence Debate: Corticosteroid Injection—Helpful or Harmful?

Proponents:

• Rapid pain relief in acute flares.
• Facilitates engagement with physiotherapy (pain-free eccentric loading).

Critics:

• Impairs collagen synthesis.[15]
• Increases rupture risk (especially with intratendinous injection or repeated doses).[16]
• No long-term benefit (symptoms recur after 3 months).

Current Consensus (NICE, BOFAS):

• Use Sparingly: Reserve for refractory cases (> 6 weeks) preventing physiotherapy participation.
• Ultrasound-Guided Only: Peritendinous technique.
• Max 1-2 Injections: Lifetime limit per tendon.
• Avoid in Athletes: Pre-competition risk of rupture.

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11. Patient/Layperson Explanation

The "Shoelace" Analogy

Imagine a shoelace (your tendon) repeatedly sliding through a metal eyelet (the retinaculum/tunnel) in your shoe. Normally, the lace is smooth and glides effortlessly.

What Happens in Tendonitis:

• Overuse: You pull the lace back and forth thousands of times (walking, running) → the lace starts to fray.
• Inflammation: The frayed lace swells, making it harder to slide through the eyelet.
• Pain: Every time you pull the lace, the rough, swollen parts catch and grind → pain and a "crunching" feeling.

Treatment:

• Rest: Stop pulling the lace for a while (reduce activity) → gives it time to "un-fray."
• Ice: Reduces the swelling.
• Stretching/Strengthening: Gradually makes the lace stronger and more flexible.
• Fix the Eyelet: If the eyelet is too tight (tight shoelaces, boots), we loosen it or create more space.

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Frequently Asked Questions (FAQ)

Q1: Will I need surgery?

A: Very unlikely. 80-85% of people improve with simple measures: changing how you lace your shoes, reducing activity for a few weeks, and doing specific exercises. Surgery is only for severe cases that don't improve after 6 months or if the tendon tears completely.

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Q2: Can I still exercise?

A: Yes, but modify it. Avoid activities that hurt (running, walking uphill). Switch to swimming, cycling, or elliptical (these don't strain the front of your ankle). After 2-4 weeks, gradually return to running on flat surfaces.

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Q3: How long until I'm better?

A: Mild cases: 2-4 weeks. Moderate cases: 6-12 weeks. Chronic/severe: 3-6 months.

Tendons heal slowly because they have poor blood supply. Be patient and stick to the exercises.

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Q4: Should I get a steroid injection?

A: Only if you've tried everything else for 6+ weeks and pain is stopping you from doing physiotherapy. Steroid injections give quick relief but don't fix the underlying problem. There's also a small risk of tendon rupture if done incorrectly or repeated too often. Always ultrasound-guided, max 1-2 injections.

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Q5: Why does my ankle "crack" or "crunch"?

A: That's called crepitus. It's the inflamed tendon sheath (the slippery covering around the tendon) rubbing against the tendon. It sounds scary but is harmless. It usually goes away as inflammation settles.

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Q6: Is it dangerous to "push through the pain"?

A: Early stages: Mild discomfort (3-4/10 pain) during exercises is okay and helps healing. Sharp pain (> 5/10): Stop. You're overloading the tendon and making it worse. A frayed tendon that's repeatedly overloaded can tear completely.

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12. Specific Clinical Scenarios

Case 1: The Marathon Trainee

Presentation: 32-year-old female, training for first marathon. Increased mileage from 20 to 50 km/week over 3 weeks. Developed progressive dorsal ankle pain, worse after long runs.

Examination: Tender over TA tendon at anterior ankle; pain with resisted dorsiflexion; TA Stretch Test positive.

Diagnosis: Reactive TA tendinopathy (acute overload).

Management:

• Reduce mileage 50% (25 km/week).
• Cross-train (swim 2x/week).
• Skip-lace running shoes.
• Start eccentric TA protocol.
• Reassess in 2 weeks.

Outcome: Symptoms resolved in 3 weeks; gradual return to running using 10% rule; completed marathon 4 months later.

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Case 2: The Military Recruit ("Boot Tendonitis")

Presentation: 19-year-old male, 2 weeks into basic training. Bilateral anterior ankle pain after 10-mile march in combat boots.

Examination: Focal tenderness directly under boot lace knot; mild swelling; crepitus on dorsiflexion.

Diagnosis: Lace bite (focal tenosynovitis).

Management:

• Gel pads placed under boot tongue.
• Skip-lace pattern (leave middle eyelets unlaced).
• Ice post-march.
• Ibuprofen 400mg TDS x 5 days.
• Gradual return to marching (5 miles → 10 miles over 2 weeks).

Outcome: Resolved within 1 week; no recurrence.

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Case 3: The Elderly Foot Drop

Presentation: 67-year-old male with diabetes. Sudden onset "foot drop" after bending down to tie shoes. Denies trauma. No back pain.

Examination: Weak dorsiflexion (2/5); palpable gap in TA tendon at anterior ankle; normal inversion (TP intact); normal toe extension (EHL intact); no sensory loss.

Imaging: MRI shows complete TA rupture with 3cm retraction.

Diagnosis: Spontaneous TA rupture (chronic tendinosis + diabetic tendinopathy).

Management: Surgical repair (primary end-to-end suture, augmented with side-to-side repair due to poor tissue quality). 4 weeks boot immobilization. 3 months PT.

Outcome: Regained 80% dorsiflexion strength; no longer requires AFO (ankle-foot orthosis).

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Case 4: The Diagnostic Challenge (Stress Fracture Mimicker)

Presentation: 28-year-old female runner. Dorsal foot pain for 4 weeks, progressively worsening. No relief with rest. Tried NSAIDs without benefit.

Examination: Diffuse dorsal midfoot tenderness; pain with resisted toe extension (EDL); but also pain with single-leg hop test.

Imaging: X-ray normal. MRI: 2nd metatarsal stress fracture with bone marrow edema. (Incidental finding: Mild EDL tendinosis.)

Diagnosis: Metatarsal stress fracture (primary), with secondary EDL tendonitis.

Management: 6 weeks non-weight-bearing boot (stress fracture takes priority). PT for tendonitis after fracture healed.

Outcome: Fracture healed; tendonitis resolved with graduated return to running.

Pearl: Always consider stress fracture in dorsal foot pain unresponsive to conservative Rx. Hop test is a useful screen.

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13. Examination Focus

High-Yield Exam Topics

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Sample Viva Questions

Q1: A runner presents with anterior ankle pain worse with dorsiflexion. How do you examine?

Model Answer: "I would perform a structured examination:

1. Inspection: Look for swelling over the dorsum, assess gait for foot slap or toe drag.
2. Palpation: Palpate the TA, EHL, EDL tendons from proximal to distal, noting focal tenderness or gaps.
3. ROM: Assess active and passive dorsiflexion and toe extension; compare to contralateral.
4. Strength: Test resisted dorsiflexion (TA), great toe extension (EHL), lesser toe extension (EDL); grade using Oxford scale.
5. Special Tests: Perform TA Stretch Test (passive plantarflexion + inversion reproduces pain); Hop Test (screen for stress fracture).
6. Differential: Palpate for anterior ankle osteophytes (impingement), check for Tinel's over superficial peroneal nerve."

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Q2: What is the management of acute TA tendonitis in a marathon runner 6 weeks before a race?

Model Answer: "The priority is rapid symptom resolution while maintaining fitness:

1. Activity Modification: Reduce running volume 50%; avoid hills; maintain flat, soft-surface running.
2. Footwear: Skip-lace shoes; consider gel pads.
3. Eccentric Loading: Start TA eccentric protocol immediately (3x15, 2x daily).
4. Cross-Training: Substitute 2 runs/week with swimming or cycling to maintain cardiovascular fitness.
5. NSAIDs: Short course (7 days) ibuprofen 400mg TDS if severe pain limiting rehab.
6. NO Steroid Injection: Avoid—rupture risk in an athlete close to competition.
7. Gradual Return: Progress running volume weekly using 10% rule; taper appropriately before race. If symptoms persist > 2 weeks, consider MRI to rule out stress fracture or significant tendinosis, which may necessitate race withdrawal."

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Q3: How do you distinguish TA rupture from L5 radiculopathy?

Model Answer:

If in doubt, MRI both ankle and lumbar spine."

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Common OSCE/Clinical Exam Pitfalls

• ❌ Confusing Extensor Tendonitis with Achilles Tendonitis: Pain is anterior (front) in extensor, posterior (back) in Achilles. Always clarify location.

• ❌ Injecting Steroid Intratendinously: ALWAYS peritendinous (sheath). Ultrasound guidance mandatory.

• ❌ Missing Stress Fracture: If pain unresponsive to 2 weeks rest, or positive hop test, order MRI to rule out metatarsal/navicular fracture.

• ❌ Skipping Footwear Assessment: Lace bite resolves with skip-lacing in 1-2 weeks—cheapest, fastest cure. Always ask about and examine footwear.

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Last Reviewed: 2026-01-06 | MedVellum Editorial Team

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Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists and current guidelines.