- Discussion:
- talar instability is assessed w/ talar tilt test, in which angle formed by tibial plafond & talar dome is measured as inversion force is applied to hindfoot;
- talar tilt test is useful for evaluation of a combined injury of both the anterior talofibular and the calcaneofibular ligaments.
- isolated rupture of the calcaneofibular ligament probably does not cause demonstrable ankle laxity;
- talar tilt to range from 0 to 23 degrees but most normal ankles have a tilt of approx 5 deg or less;
- testing w/ ankle in plantar flexion assesses anterior talofibular ligament primarily and the calcaneofibular ligament secondarily;
- when the anterior talofibular ligament alone is ruptured, small increases in talar tilt are noted;
- combined rupture of anterior talofibular ligament & calcaneo-fibular ligament results in increased talar tilt;
- Method of Testing:
- talar tilt test is performed w/ patient seated & w/ ankle & foot unsupported in 10 to 20 degrees of plantar flexion;
- examiner stabilizes the medial aspect of the distal part of leg, just proximal to medial malleolus, with one hand & applies inversion
force slowly to the hindfoot with the other hand;
- lateral aspect of the talus should be palpated during inversion of hindfoot to determine if tilting is occurring at ankle joint