Meniscus

What it means

Each knee holds two menisci — rubbery, C-shaped pads of cartilage that sit between the rounded end of the thigh bone and the flat top of the shin bone, one on the inner side and one on the outer side. They act as shock absorbers, spreading the body's weight evenly across the joint, and they help keep the knee stable as it bends and twists. Without them the two bones would grind against each other with every step.

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

The meniscus is normal anatomy, so it is named when the radiologist describes a change: a tear, a fray, thinning, a small cyst, or general degeneration. Reports often specify which meniscus (medial or lateral) and which part (front horn, body, or back horn). Because the menisci are soft tissue, they are seen best on MRI, which can grade the wear and show the exact tear pattern. X-ray and CT mainly show the bones and any narrowing of the joint space.

What it usually means

Meniscal wear is extremely common with age. The cartilage gradually dries out and frays, and degenerative tears turn up routinely on the MRIs of adults over 40 who have no knee pain at all — large studies have found meniscal tears in many symptom-free knees. So a meniscus described as worn or torn on a scan is often an incidental, age-related finding rather than something that needs surgery. What matters is whether it matches symptoms such as pain along the joint line, swelling, or a sense of catching or locking. Most degenerative meniscal changes settle with physical therapy, anti-inflammatories, and activity changes. Acute tears in younger active people, especially a bucket-handle tear that locks the knee, are more likely to be considered for an arthroscopic trim or repair.

When to follow up

The meniscus being named is anatomy; act on what is described and how the knee feels. See your doctor if you have knee pain after a twist, persistent swelling, or a feeling that the knee catches, clicks, or locks. They will match the scan to your exam to choose between physical therapy, activity changes, injections, or an arthroscopic opinion. A sudden locked knee that will not straighten after an injury deserves prompt care. A meniscus simply showing mild age-related wear without symptoms usually needs no action.

A plain-language way to picture it

Imagine two smooth stones with a thick, C-shaped rubber washer between them on each side. The washers stop the stones grinding and spread the load so neither one takes all the pressure. Over years the rubber dries and cracks at the edges — usually harmlessly. The menisci are those washers inside the knee, quietly cushioning every step.