Injuries of the Ligaments and Tendons in Ankle and Foot

This chapter addresses sports-related injuries of ligaments and tendons of the ankle and foot with emphasis on trauma mechanisms and optimal imaging modalities and findings. The ankle is one of the most common sites of injury in sports with ankle sprain being the most frequent injury. Ligamentous elongations or tears tend to be acute whereas tendinosis is more typically due to overuse and repetitive trauma. Acute tendon tears usually occur in an already diseased tendon. Clinical diagnosis can be challenging due to the complex anatomy and multiple sites of potential injury. Ultrasound is perfectly suited for foot and ankle evaluation as most structures are located superficially. Moreover it allows dynamic assessment of ligaments and tendons towards the static CT or MRI. MRI is also an ideal modality because of the high soft-tissue contrast. It is essential in assessing associated intra-articular lesions and bone marrow oedema. Radiography and CT are a good complement of MRI for detection of bony avulsions and soft-tissue calcifications. Early MRI of the sprained ankle in the athlete can help to assess the severity of ligament injuries (involving lateral ligament complex, syndesmotic complex, deltoid complex, spring or subtalar ligaments as well as Chopart and Lisfranc ligaments in the midfoot). MRI is also capable to depict the first MTP joint ligamentous injuries. Tendon disorders can be analysed on US and MR images based on the clinical findings and the tendon location (peroneal, flexor, extensor, plantar and posterior).