Ankle – Posterior tibial tendon tear

CASE HISTORY

Injury to the ankle with painful lump medially. 

TECHNICAL FACTORS

Long- and short-axis fat- and water-weighted images were performed. 3D reformatted imaging included.

KEY IMAGES

This case has no key images.

CASE FINDINGS

• Although demographically and statistically uncommon an interstitial hypertrophic tear has evolved along the distal aspect of the posterior tibial tendon involving its distal 2cm. Reactive swelling surrounds the injury as well as the adjacent spring ligament and navicular producing a sterile inflammatory pseudomass. The tendon itself is hypertrophic and tapers to normal size with the adjacent flexor digitorum and hallucis unremarkable. 
• Hypertrophic navicular with irregular cortical contours but no accessory navicular noted. 
• Deltoid unremarkable. 
• Medial malleolus unremarkable. 
• Mild middle facet subtalar arthrosis but no coalition identified. 
• Other and perhaps incidental findings include a) susceptibility effect in the plantar space perhaps from prior injection b) midfoot arthrosis c) mild swelling or strain of the soleus d) peritendinitis and fraying of the peroneus complex with peroneus quartus inserting on the peroneal calcaneal tubercle. 

CASE CONCLUSION

Unusual distal insertional interstitial hypertrophic tear of the posterior tibial tendon with additional detailed findings described in the body of the report.