Talus Fractures

Fig. 7.45. Os trigonum simulating fracture of posterior process of the talus (arrow). The calcaneal apophysis appears sclerotic and fragmented but this is normal...

Magnetic resonance (MR) imaging for acute paediatric ankle injuries conveys no real advantage over radiography (Lohman et al. 2001). It is probably as useful as CT in the assessment of transitional fractures and is also helpful in the evaluation of the articular cartilage in traumatic osteochondral lesions of the talus. Where it is perhaps most useful is in the later stages, following physeal injury, to identify and characterise physeal arrest (Futami et al. 2000 Sailhan et al. 2004). 

Fig. 15.6a-e. Talar neck fracture. a,b Initial films, c Internal fixation. d,e Isotope bone scan showing lack of uptake in body of talus... 

In the talus the terms osteochondral fracture, tran-schondral fracture and osteochondritis dissecans are used interchangeably. The condition is usually seen in adolescence. An associated history of trauma is identified in 64%-92% of patients (Berndt and Harty 1959 Ogilvie-Harris and Sarrosa 1999 Stone 1996) and tends to be an inversion type injury. Lateral lesions are said to be more commonly associated with trauma than medial lesions. The initial complaint is of ankle pain, swelling and a limp. Symptoms of instability and locking or clicking within the joint may also be described. 

Peterson CA, Peterson HA (1972) Analysis ofthe incidence of injuries to the epiphyseal growth plate. J Trauma 12 275-281 Powell H (1961) Extra centre of ossification for the medial malleolus in children. J Bone Joint Surg 43B 107-113 Rammelt S, Zwipp H, Gavlik JM (2000) Avascular necrosis after minimally displaced talus fracture in a child. Foot Ankle Int 21 1030-1036... 

The triangular deltoid ligament is located medially and is attached above to the medial malleolus and below to the tuberosity of the navicular, the sustentaculum tali of the calcaneus, and the medial tubercle of the talus. The deltoid ligament is so strong that trauma often causes fractures of its bony attachments rather than rupture of the ligament itself. 

The shape of the crural concavity, the extent of the lateral malleolus on the talus, and the strong ligamentous attachments deter joint dislocations unless accompanied by fracture of the malleoli. 

On plain films, one of the most commonly overlooked (up to 50% of cases) fractures of the ankle is that involving the lateral process of the talus. The prevalence of this fracture has increased in recent years, especially as a result of winter sports such as snowboarding. Clinically, the diagnosis of this fracture is challenging because patients present with... 

Fig. 16.91 a-c. Fracture of the lateral process of the talus in a patient with negative standard radiographs of the ankle, a Coronal 12-5 MHz US image over the lateral ankle reveals an interruption (arrow) of the hyperechoic cortical profile of the talus, consistent with a fracture of its lateral process. Note the intra-articular effusion within the posterior talocalcaneal joint (asterisks). b Oblique coronal CT reconstruction confirmed the talar fracture (arrow), c Schematic drawing of a coronal view of the ankle illustrates the position of the fracture (arrows) and the involvement of the adjacent talocalcaneal joint (asterisk)... 

Bonvin F, Montet X, Copercini M et al (2003) Imaging of fractures of the lateral process of the talus, a frequently missed diagnosis. Eur J Ultrasound 47 64-70 Bouffard JA, Goitz HT, van Holsbeeck MT (1996) Sonographic evaluation of high-ankle sprains. Radiology 201(P) 399... 

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