This page is educational and is not a substitute for professional medical advice, diagnosis, or treatment.
Please ask a qualified health professional about symptoms, treatment decisions, or concerns about your own condition.
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Bones & Joints
Peroneal tendon injuries involve tears, splits, or subluxation (dislocation) of the two tendons (peroneus longus and brevis) running behind the outside ankle bone (lateral malleolus), which evert the foot (turn sole outward) and stabilize the ankle, most commonly affecting athletes in cutting sports, dancers, and individuals with high-arched (cavus) feet or chronic ankle instability. These injuries range from peroneal tendinitis (inflammation from overuse—20-30% of lateral ankle pain in runners), to longitudinal splits within tendons (peroneus brevis most commonly affected—tears along length of tendon), to complete ruptures, and peroneal subluxation/dislocation (tendons slip out from behind ankle bone during movement due to torn retinaculum—restraining band holding tendons in groove). Patients present with lateral ankle pain, swelling behind outer ankle bone, clicking or snapping sensation (if subluxing), and weakness with foot eversion. Diagnosis requires high clinical suspicion as often misdiagnosed as lateral ankle sprain, with ultrasound or MRI confirming tendon tears, splits, or subluxation. Treatment depends on injury pattern: acute tendinitis managed conservatively with immobilization, physiotherapy, and NSAIDs (70-80% success); chronic tendinosis or partial splits may need 3-4 months conservative management before considering surgery; complete ruptures, large longitudinal splits, and recurrent subluxation typically require surgical repair (debridement of diseased tissue, tubularization of split tendons, groove deepening for subluxation). Surgical outcomes: 75-85% good-to-excellent results with tendon repair/reconstruction, though return to high-level sports takes 6-9 months and recurrence of subluxation occurs in 5-15% despite surgery.
What it is and why it happens
Peroneal tendon injuries involve tears, splits, or subluxation (dislocation) of the two tendons (peroneus longus and brevis) running behind the outside ankle bone (lateral malleolus), which evert the foot (turn sole outward) and stabilize the ankle, most commonly affecting athletes in cutting sports, dancers, and individuals with high-arched (cavus) feet or chronic ankle instability. These injuries range from peroneal tendinitis (inflammation from overuse—20-30% of lateral ankle pain in runners), to longitudinal splits within tendons (peroneus brevis most commonly affected—tears along length of tendon), to complete ruptures, and peroneal subluxation/dislocation (tendons slip out from behind ankle bone during movement due to torn retinaculum—restraining band holding tendons in groove). Patients present with lateral ankle pain, swelling behind outer ankle bone, clicking or snapping sensation (if subluxing), and weakness with foot eversion. Diagnosis requires high clinical suspicion as often misdiagnosed as lateral ankle sprain, with ultrasound or MRI confirming tendon tears, splits, or subluxation. Treatment depends on injury pattern: acute tendinitis managed conservatively with immobilization, physiotherapy, and NSAIDs (70-80% success); chronic tendinosis or partial splits may need 3-4 months conservative management before considering surgery; complete ruptures, large longitudinal splits, and recurrent subluxation typically require surgical repair (debridement of diseased tissue, tubularization of split tendons, groove deepening for subluxation). Surgical outcomes: 75-85% good-to-excellent results with tendon repair/reconstruction, though return to high-level sports takes 6-9 months and recurrence of subluxation occurs in 5-15% despite surgery.