Knee Pain

What tends to cause it

Where the pain sits, and what brings it on, usually narrows things down a long way before any scan is needed.

• Osteoarthritis. Gradual, worse on stairs and after rest, often with stiffness in the morning that eases as you move. The most common cause over the age of fifty.
• Meniscus tears. Pain on the inner or outer joint line, sometimes with catching, clicking or the knee locking. Can follow a twist, or appear with no injury at all in an older knee.
• Ligament injuries. The ACL and MCL in particular. Usually a clear moment of injury, swelling within hours, and a knee that feels unreliable when turning.
• Patellofemoral pain. Ache around or behind the kneecap, worse sitting for long periods, on stairs, or squatting. Common in younger and more active people.
• Tendon problems. Pain just above or below the kneecap that comes on with jumping and running.
• Referred pain. A hip problem or a nerve in the back can send pain to the knee, which is why the examination does not stop at the knee itself.

When it needs seeing sooner

Most knee pain can wait for a routine appointment. Some cannot. Get seen urgently, at a hospital rather than a clinic, if any of these apply:

• The knee is hot, red and swollen and you feel unwell or feverish. An infected joint is an emergency.
• You cannot put any weight on the leg after an injury, or the knee looks deformed.
• The knee is locked and will not straighten.
• It swelled up within an hour of an injury, which often means bleeding inside the joint.
• You have calf pain and swelling alongside it, or breathlessness.

Short of those, book a consultation and bring any imaging you already have.

How it gets assessed

The history does most of the work. When it started, what you were doing, where exactly it hurts, what makes it worse, whether it swells, whether it gives way, and what you have already tried.

Examination then tests the structures one at a time: range of movement, joint line tenderness, ligament stability, kneecap tracking, and how the hip and the whole leg line up.

Imaging follows the examination rather than replacing it. Standing X-rays show joint space and alignment, which lying-down films miss. An MRI is useful for ligaments, cartilage and meniscus, but it is worth knowing that MRIs in people over forty routinely show meniscal tears that are not the source of the pain. A scan finding only matters if it matches the examination.

What treatment usually looks like

Surgery is the last option discussed, not the first. Most knee pain improves with some combination of:

• A physiotherapy programme aimed at the specific problem, particularly quadriceps and hip strength
• Changing what aggravates it for a period, without stopping activity altogether
• Weight reduction where it applies, which lifts several times body weight off the joint with each step
• Anti-inflammatory medication for a defined period rather than indefinitely
• An injection into the joint in selected cases, to settle things enough for rehabilitation to work
• A brace or insole where alignment is part of the problem

Surgery enters the conversation when the structure is mechanically damaged in a way that will not heal, when instability is causing repeated episodes, or when arthritis has reached the point that non-surgical treatment has stopped holding it.

Common questions

Related procedures

Where an operation does turn out to be the right answer, these are the ones this problem most often leads to.