Os-Trigonum Syndrome

Patient Information

https://physioworks.com.au/injuries-conditions-1/posterior-ankle-impingement

GP Information

Background Information

• An Os trigonum is a congenital accessory bone behind the talus that is classically asymptomatic
• Symptoms may occur following forced or repetitive plantar flexion causing stretching or tearing of the connecting soft tissue, or even fracture.
• DDx include Achilles pathology or talus fracture
• Patients typically complain of pain pain in the back of the ankle, worse on push off and plantarflexion.
• Examination may reveal localised tenderness or swelling.

Investigation Guidelines

• Diagnosis may be confirmed with plain radiographs.

Management Recommendations

Treatment is normally conservative

• Prescribe PRICE
• Short term NSAIDs
• Steroid injections are appropriate if skilled with a confirmed diagnosis.
• Physiotherapy for stretching exercises.

Referral Indications

• Diagnostic uncertainty
• Failure of conservative measures after a minimum of 3months
• Referral for formal physiotherapy
• Referral for steroid injection or arthroscopic or open excision.