Where Your Knee Hurts, and What That Suggests

Most people describe knee pain by pointing at it. That instinct is a good one, because where a knee hurts genuinely narrows down what is happening inside it — the knee is not one joint but three compartments, plus the ligaments, tendons and bursae around them, and they produce different patterns.

What location cannot do is give you a diagnosis. Two people pointing at exactly the same spot can have entirely different problems, and the thing that separates them is usually the timing: how it started, what brings it on, what it has done over the past year. This page covers both — where, and when.

It is not a substitute for an examination. It is here so that you can describe your knee more precisely, and so that the conversation at an appointment starts further along.

Pain at the front

The front of the knee is the kneecap and the groove in the thigh bone it slides through — the patellofemoral compartment. It is loaded hardest when the knee is bent under weight, which is why the pattern is so recognisable:

• Pain going down stairs more than up
• Pain standing up from a low chair or getting out of the car
• Aching after sitting for a long stretch with the knee bent — long drives, the cinema
• Discomfort squatting or kneeling

Arthritis behind the kneecap produces this pattern, and it is one of the three compartments assessed when deciding which knee operation, if any, suits a knee. In younger and more active people the same area more often points to a tendon problem — the patellar tendon below the kneecap, or the quadriceps tendon above it — which is activity-related, tender to press on, and tends to warm up as you get going.

Swelling sitting right on top of the kneecap, rather than inside the joint, is usually prepatellar bursitis. It is common in people who kneel for work.

Pain on the inner side

This is the most common location of all, for a straightforward mechanical reason: the medial compartment carries more load than the outer side, so it usually wears first. Inner-side pain is the typical presentation of knee osteoarthritis.

Two things produce pain in almost the same place, and telling them apart matters because the treatment differs:

Medial compartment arthritis builds gradually — months or years. It is worse the longer you are on your feet, better after rest, stiff first thing in the morning but loosening within half an hour. Walking distance shrinks over time. Over years it can produce a bow-legged appearance as the inner side loses height.

A medial meniscus tear more often has a beginning. A twist, a deep squat, getting up awkwardly — in older knees sometimes nothing memorable at all. It tends to catch, click or give way, and can be sharply tender along the joint line.

The two frequently coexist, particularly after 50, and a tear found on a scan is often part of the arthritis rather than a separate problem needing separate treatment. That distinction is worth getting right — it is the difference between an operation that helps and one that does not.

Pain slightly below the joint line on the inner side, in a small localised spot, is more likely pes anserine bursitis, where several tendons share an attachment.

Pain on the outer side

The lateral compartment wears less often than the medial, so isolated outer-side arthritis is less common — though when it does occur it can produce a knock-kneed alignment, and it is one of the patterns a partial knee replacement can address.

In runners and cyclists, pain on the outside just above the joint line that comes on predictably after a certain distance and settles with rest is usually iliotibial band syndrome rather than anything inside the joint.

A lateral meniscus tear and an injury to the outer collateral ligament both present here, generally after a specific incident.

Pain behind the knee

Pain at the back is the pattern most likely to be something other than the joint surface itself.

The common cause is a Baker’s cyst. An irritated knee — from arthritis or a meniscus tear — produces excess fluid, and if the underlying cause is not addressed the fluid keeps coming and drains backwards into a pouch behind the joint. It feels like fullness or tightness rather than sharp pain, and is worse when you bend the knee fully. Treating the cyst without treating what is producing the fluid tends to be temporary.

Hamstring tendon problems, and tears at the back attachment of a meniscus, also present here.

Pain everywhere

Pain that is diffuse and hard to localise, in a knee that is often swollen and stiff, is a different pattern. It can mean arthritis in more than one compartment, which is the usual reason a total knee replacement is considered rather than a partial one.

It can also point away from osteoarthritis altogether — towards an inflammatory arthritis such as rheumatoid, or towards gout. The tell is usually the timing rather than the location, and it is covered in Is It Knee Arthritis or Something Else?.

What the timing adds

Location narrows the field. Timing usually decides it.

The last one matters more than people expect. Night pain and shrinking walking distance are two of the things weighed most heavily when considering whether a knee replacement is reasonable — considerably more than how the X-ray looks.

When to be seen urgently

Most knee pain is not an emergency. These are the exceptions:

• A knee that is hot, very swollen and painful, especially with fever or feeling generally unwell — infection must be excluded the same day
• Pain behind the knee with a swollen or tender calf — as above
• After an injury: unable to weight bear, an obvious deformity, or a knee that swells hard within an hour
• Severe, constant pain that is unrelated to position and unrelieved by rest

What happens next

If the pattern above sounds like arthritis, Understanding Knee Arthritis explains the condition itself, and Treating Knee Arthritis Without Surgery covers what the evidence supports before an operation is considered.

If you are not sure whether what you have is arthritis at all, Is It Knee Arthritis or Something Else? works through the alternatives.

If you have been told you need a scan, or already have one, What Knee Scans Actually Show explains what each type of imaging can and cannot answer.

Appointments can be made on (08) 6332 6365 or through the contact page. A GP referral is usually needed to claim the Medicare rebate for a specialist consultation.