Hairline fracture of the medial malleolus: what to know

The medial malleolus is the inner bony prominence of the ankle and part of the joint’s stabilising structure. A crack may cause pinpoint tenderness, swelling, bruising, and pain when standing or turning the foot. You may limp because the ankle cannot comfortably accept normal load. A clinician checks the skin, circulation, sensation, ankle alignment, and nearby bones. X-rays are commonly considered, although a small stress-related crack may be difficult to see early. Repeated loading, an ankle injury, or bone-health factors such as vitamin D deficiency may be relevant.

Limit walking and avoid running, jumping, uneven ground, and movements that roll the ankle. Use crutches, a boot, or another support only as advised, especially if weight-bearing is painful. Elevate the ankle and apply a wrapped cold pack for short periods to help with swelling. Keep any splint or boot dry and check the toes for colour, warmth, and sensation. Do not loosen or alter prescribed support without advice. A gradual return to walking and sport should follow clinical review rather than pain alone.

Arrange prompt assessment for inner-ankle tenderness, swelling, bruising, or difficulty taking steps. Seek emergency help if the ankle is deformed, the skin is broken, the toes become blue, pale, cold, numb, or increasingly swollen, or pain becomes severe despite support. Urgent review is also needed after a significant twist or fall when you cannot bear weight safely. Return for reassessment if symptoms worsen or recur during increased walking.

Ask whether the fracture is stable, how much weight is allowed, and whether you need a boot, cast, crutches, or repeat imaging. Discuss ankle exercises, driving, work, footwear, return to sport, and whether vitamin D or bone-health checks are relevant.