Malleolus

What it means

A malleolus is one of the bony knobs on either side of your ankle. The bump on the inner side is the lower tip of the larger shin bone, and the bump on the outer side is the lower tip of the slimmer calf bone. Together they form a snug bracket that grips the top of the foot bone, holding the ankle joint steady. You can feel both of them easily as the firm lumps just above your foot.

Why it appears on a CT, MRI or X-ray report

Radiologists name a malleolus to point to which side of the ankle a finding sits on. Because the ankle is twisted and sprained so often, these bumps are a very common place to describe fractures, chips, swelling, or ligament strain. Reports may note an inner, outer, or both-sided fracture, how well the pieces line up, or whether the joint sits evenly. Naming the specific malleolus simply marks the exact spot.

What it usually means

In most reports, malleolus is just a location word for one of the ankle bumps. It does not by itself mean anything is wrong. Often it is described as normal or intact, and the term is only there to map the ankle. When a finding is noted, it is commonly something familiar: a fracture or chip after a roll or twist, swelling of the nearby soft tissues, or a healed old injury. Ankle fractures here range widely; many heal well in a boot or cast, while some that disturb the joint line need a specialist or a procedure to set the pieces. None of this is signalled by the Latin name itself. What matters is the description beside it, especially whether the joint is lined up and stable, which is what guides treatment.

When to follow up

The name alone needs no action. What deserves attention is whatever the report says, such as a fracture, displaced pieces, or a joint that is not sitting evenly. If your report mentions these, ask your doctor whether you need a boot, a cast, or an orthopaedic specialist, particularly if you cannot put weight on the ankle. Seek prompt care for an ankle that is obviously deformed, severely swollen, numb, or that you cannot stand on.

A plain-language way to picture it

Picture your ankle joint as a wheel held between the two arms of a clamp. The malleoli are the rounded ends of those two arms, the knobs you can feel on each side of your ankle, gripping the joint and keeping it from wobbling. When you roll your ankle, those arms take a lot of the strain, which is why they so often turn up on ankle reports.