What Does a Torn Meniscus Look Like on the Outside? Signs to Check

You twisted your knee, and now it feels wrong. You look down expecting to see something, and there is not much there. Maybe a little puffy, maybe a bit tight. That is exactly what most torn menisci look like from the outside, and it is why so many people wait too long to get one checked.

Usually like a swollen, stiff knee, and not much else. According to the American Academy of Orthopaedic Surgeons (AAOS), most people can still walk after a meniscus tear, but over 2 to 3 days the knee gradually becomes stiffer and more swollen. A tear does not usually cause a visible lump, dent or deformity, because the meniscus sits deep inside the joint.

So the knee's appearance only tells you part of the story. The more telling signs are what the knee does: catching or locking, giving way, pain when you twist or squat, and trouble bending or straightening it all the way.

The meniscus is a C-shaped piece of rubbery cartilage that cushions the joint between your thighbone and shinbone. You have two in each knee, one on the inner side and one on the outer side. When one tears, here is what can show on the outside.

Not every tear comes from a sports injury. As we age, the meniscus wears and becomes more prone to tearing, and the AAOS notes that an awkward twist when getting up from a chair can be enough to tear an aging meniscus. These wear-related tears often cause less dramatic swelling than a sudden injury, so the knee can look almost normal while it still catches, aches or feels unreliable.

That is the trap. A knee that looks fine is easy to ignore, but the symptoms below matter more than how it looks.

The AAOS lists these as the common symptoms of a meniscus tear:

• Pain, which many people notice most when they twist or pivot.

• Stiffness and swelling.

• Catching or locking, a feeling that something is getting stuck as the knee moves.

• Giving way, a sense that the knee might buckle under you.

• Not being able to move the knee through its full range of motion.

Many people also feel a pop at the moment of the tear. When a doctor examines you, they check for tenderness along the joint line, the crease where the thighbone meets the shinbone, because pain there often points to a tear. Pain on the inner side of the knee fits the inner meniscus, and pain on the outer side fits the outer one.

If the back of your knee hurts when you straighten your leg, a torn meniscus is one of several possible causes, which we cover in pain in the back of the knee when straightening the leg.

A twisting injury can tear the meniscus, a ligament, or both, so it helps to know how they tend to differ. According to the AAOS guide to ACL injuries, with an ACL tear you might hear a popping noise, may feel your knee give out from under you, and the knee typically swells within 24 hours. With a meniscus tear, swelling more often builds gradually over 2 to 3 days, and catching or locking is more typical.

These are patterns, not rules. The AAOS also notes that people who tear their ACL commonly tear a meniscus at the same time. You cannot reliably tell them apart by looking at the knee, which is why an examination matters.

You can learn a lot by watching your knee for a few days. Compare its size with the other knee, notice whether it catches or locks on stairs, and see whether you can fully straighten it when you stand. Write down what you notice, because it helps at your appointment.

What you cannot do at home is confirm a tear. In the clinic, a doctor bends your knee, then straightens and rotates it (the McMurray test), which puts tension on a torn meniscus and may cause pain or a clicking sensation. An X-ray will not show a meniscus tear, because the meniscus is cartilage, though it can show other problems. The AAOS describes MRI as the preferred method of diagnosing acute meniscus tears because of its high level of accuracy.

For most sports-related knee injuries, the AAOS recommends the RICE approach while you wait to be seen:

• Rest: take a break from the activity that caused the injury, especially twisting and pivoting.

• Ice: use cold packs for 20 minutes at a time, several times a day.

• Compression: an elastic bandage can help limit swelling.

• Elevation: recline and keep your leg higher than your heart.

Anti-inflammatory medicines such as ibuprofen or naproxen can help with pain and swelling. Check with a doctor or pharmacist first if you take other medicines or have stomach, kidney or heart problems.

The NHS advises getting urgent advice for knee pain if:

• your knee is very painful

• you cannot move your knee or put any weight on it

• your knee is badly swollen or has changed shape

• your knee locks, gives way or painfully clicks

A knee that stays locked and will not straighten needs prompt attention, because a torn piece of meniscus can be caught in the joint. If your knee is hot and red and you have a high temperature or feel shivery, get urgent medical advice right away, because this can be a sign of infection.

An orthopedic specialist will ask how the injury happened, examine the knee, and order imaging when it will change the plan. Treatment then depends on the type of tear, where it is, and what your knee is doing.

A torn meniscus rarely looks dramatic, so do not judge your knee by how it looks. If it swelled after a twist, catches, locks, gives way, or still is not right after a week or two, have it examined. The orthopedic specialists at Mountain Spine & Orthopedics evaluate knee pain and can guide your care from diagnosis through nonsurgical options such as a physical therapy plan and injections, or arthroscopic knee surgery when it is the right tool. Find a doctor near you to book an evaluation.