Talus fracture in children

Talus fracture in childrenTalus #Very rare 0.01 0.08%Most common talar neck #osteonecrosis, may be more common in adolescents than in adultAnatomy Head, neck and bodyHead mostly cartilagenousNeck vascular perforationTarsal canal funnel shaped sulcus between talus and calcaneumPosteromedial to anterolateral opening as funnel shaped sinus tarsiAccommodates artery of sinus tarsi and tarsal canal

2/3 is covered with articular cartilageLateral process gives attachment to lateral talocalcaneal ligamentOssification begins in head and neck and then proceeds to body in a retrograde fashionLess ossified more resistant to permanent damage and can remodelLast to ossify - subchondral ankle mortise Osteonecrosis Long term disabilityAVN of the body as it received the blood supply from head and neckBody artery of tarsal canalBranch of posterior tibial arteryGives of deltoid branch before it enters the sinusDeltoid branch medial quarter of talar bodyArtery of tarsal sinus is derived from posterior lateral perforating branch of Peroneal artery and lateral branch of dorsalis pedis artery.

Clinical featuresForced dorsiflexion Compartment syndromeSoft tissue compromiseClassification Hawkins classification Type I Stable, undisplaced vertical fracture through talar neckType II Displaced fracture with subtalar joint subluxation or dislocation; normal ankle jointType III with subluxation or dislocation of both the ankle and subtalar jointType IV type III with talonavicular joint displacement

Management CT scan with 3D reconstructionApproaches posterolateral, anteromedial and anterolateral

Fractures of the Lateral Process of the Talar Body

Initially missed in 46% of patients Increasing popularity of snowboarding Combination of ankle dorsiflexion with inversion of the hindfoot Mimicking a lateral ankle sprain

Fractures of the Talar Body and Dome

Fractures of the Osteochondral Surface of the Talus

Letts found medial lesions in 79% of 24 children, lateral lesions in 21%

Adaptation of the Berndt and Hardy (1951) classification of osteochondral injuries of the talus by Anderson et al

Complications Skin necrosisAVNAVNOsteonecrosis seems to occur within 8 weeks of injury Hawkins sign - would not be easily seen in young childrenRammelt et al - immature talus may be more susceptible to itProtected weight-bearing while awaiting reossification of the talar

Ankle arthrodesisAttempt should be made to create broad, flat, cancellous surfaces that are placed into apposition to allow fusion to occurThe arthrodesis site should be stabilized with rigid internal fixation, if possible, or with external fixationThe hindfoot should be aligned to the leg and the forefoot to the hindfoot to create a plantigrade foot.

optimal position for ankle fusion 0 degrees of flexion, 0 to 5 degrees of valgus, and 5 to 10 degrees of external rotation with slight posterior displacement of the talusPhoenix ankle arthrodesis nail system

Pre-assembled/pre-embedded CoreLock mechanism is capable of 7.0 mm of inboard tibiotalar compression.Once the CoreLock mechanisms are engaged, the nail converts to a solid,fixed angle device.

Tibiotalar compression and locking is achieved independently from the talocalcaneal joint, providing the ability to compress the subtalar and ankle joints separately.