The deltoid ligament is a multilayer complex with superficial (tibionavicular, tibiospring, tibiocalcaneal) and deep (anterior and posterior tibiotalar) components. The deltoid complex is rarely torn in isolation — it typically fails when fibular fracture occurs in eversion injuries. Deltoid insufficiency after ankle fracture repair produces the medial clear space widening that indicates continued instability despite lateral fixation.
| Origin | Medial malleolus (anterior colliculus for superficial; posterior colliculus for deep) |
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| Insertion | Multiple: navicular, spring ligament, sustentaculum tali, medial talus, and posterior talar process |
| Actions | Resists eversion, lateral talar tilt, and external rotation; the medial ankle primary static stabiliser |
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Intraoperative gravity stress radiographs after fibular fixation assess deltoid integrity — a medial clear space greater than 4 mm indicates deltoid disruption requiring direct deltoid repair or prolonged immobilisation. Chronic medial ankle instability from deltoid insufficiency requires anatomical deltoid reconstruction using gracilis or peroneus brevis autograft.
Medial ankle ligament disruption producing medial clear space widening after fibular fixation — assessed by gravity stress film and managed with deltoid repair or extended immobilisation.
