Tendinopathy in Podiatry

Definition & Terminology

• Tendinitis — historically used, implying tendon inflammation
• Tendinosis — now preferred in many cases; describes a degenerative process with disorganized collagen, mucoid degeneration, and minimal inflammatory cells rather than true inflammation

Pathophysiology

• Age, obesity, blood type O, tobacco use
• Malalignment, joint laxity, muscle weakness/imbalance

• Abnormal movements, excessive training load, frequency or intensity changes
• Ergonomic problems, environmental conditions

• Fluoroquinolone antibiotics — increase risk of tendon rupture (especially Achilles), particularly in patients >60 years, on corticosteroids, or with renal disease
• Statins (2% incidence)
• Systemic diseases: diabetes mellitus, gout, coronary artery disease

Common Tendinopathies in the Foot & Ankle

Common sites of tendinopathy and bursitis — note "Bursitis of the heel" at the Achilles tendon

1. Achilles Tendinopathy (most common in podiatry)

• Pain, swelling, burning, and stiffness at the posterior heel
• Tenderness localized to the Achilles insertion on the posterior calcaneus (midline)
• Progressive bony prominence enlargement with pain from shoe pressure
• X-ray: bone spur and intratendinous calcification (lateral foot view)
• Often co-exists with Haglund deformity (prominent superior calcaneal tuberosity) and retrocalcaneal bursitis

• Pain in the posterior lower leg/heel, worsened with push-off activities (running, stairs, hills)
• Tenderness at the mid-tendon (2–6 cm above insertion), possible palpable swelling, firmness, and "wet crepitus" (fluid in peritenon)
• Thompson test used to assess tendon integrity: prone, knee at 90°, squeeze gastrocnemius — absence of plantarflexion = positive (rupture)

2. Posterior Tibial Tendinopathy

• Tendon runs posteromedially; primary dynamic stabilizer of the medial arch
• Strongly associated with adult acquired flatfoot deformity

3. Peroneal Tendinopathy

• Peroneal longus and brevis are primary evertors and pronators of the foot
• Chronic tendinopathy can predispose to dislocation or rupture at the posterior peroneal sulcus

4. Flexor Hallucis Longus / Flexor Digitorum Longus Tendinopathy

• Posteromedial ankle tendons
• The tibialis posterior is the strongest of the posteromedial group

Imaging

Imaging changes (US/MRI) can persist in the tendon even after the patient has clinically recovered.

Treatment

Conservative (first-line, typically 6–12 weeks minimum)

• Relative rest and activity modification
• Ice and NSAIDs (short-term)
• Stretching and eccentric strengthening — eccentric training programs (e.g., Alfredson protocol for Achilles) show promising results
• Shoe wear modification, heel lifts, silicone heel pads/sleeves
• Physiotherapy / proprioception exercises
• Nitroglycerin patches (some tendinopathies)
• Bracing/splinting as needed

Injections

• Corticosteroids: AVOID — associated with tendon rupture risk (especially Achilles)
• Platelet-rich plasma (PRP): no benefit over saline for chronic Achilles tendinopathy in trials
• Prolotherapy: mixed short-term evidence

Advanced / Refractory

• Extracorporeal shock wave therapy (ESWT): studied in chronic insertional and noninsertional disease; evidence mixed
• Surgical debridement: for chronic, failed conservative cases — includes removal of degenerative tissue, calcifications
  • If >50% of Achilles tendon is detached/excised: FHL tendon transfer is indicated
  • Dorsal closing-wedge calcaneal osteotomy (Zadek) for Haglund cases without large posterior ossification
  • Lateral/medial/midline J-shaped incision approaches described

Key Points for Podiatry Practice

• Tendinopathy accounts for ~30% of all musculoskeletal ED/urgent care presentations
• Up to 50% of sports injuries involve tendinopathy
• Always allow at least 6–12 weeks of conservative treatment before escalating
• Steroid injections around the Achilles tendon are contraindicated
• Recurrence is common (49% in patellar tendinopathy); manage patient expectations accordingly