Location of Pain

For Medical Students

What It Tests

Asking where the pain is tests which compartment or structure is likely to be involved, and it is the first question that narrows the differential.

The knee divides usefully into anterior, medial, lateral and posterior pain, and each region has a short list of causes.

The reliability of the answer varies with how it is obtained, which is why the method below matters more than on most pages.

How It Is Performed

Ask the patient to point with one finger to where it hurts most.

Do not offer regions. A patient asked whether it is on the inside will frequently agree.

Ask whether the pain stays there or moves, since migrating pain behaves differently from fixed pain.

Ask whether there is more than one site, and if so which came first.

Then palpate the site they indicated and compare it with where tenderness actually is. 4.6.1 covers systematic palpation.

What a Positive Means

Anterior pain, worse on stairs, squatting and rising from sitting, points to the patellofemoral joint. 4.15.9 covers it.

Medial joint line pain with a twisting mechanism points to the medial meniscus. 4.9.2 covers joint line tenderness.

Lateral pain in a runner points more often to the iliotibial band than to the lateral meniscus.

Posterior pain points to a cyst, a hamstring origin, or a posterior meniscal lesion, and needs the popliteal fossa examined. 4.6.10 covers it.

Diffuse pain the patient cannot localise points away from a single structural lesion.

MRCS Level

What a Positive Means

At this level the location is combined with the mechanism and the age to produce a working diagnosis before the knee is touched.

Medial pain in a young patient after a twist is a meniscal tear. Medial pain in an older patient with stiffness is degenerative disease. The location is identical.

Anterior pain in an adolescent is patellofemoral or, with tenderness over the tubercle, an apophysitis. 4.16.4 covers it.

Lateral pain after a varus injury raises the lateral collateral and the posterolateral structures. 4.13.2 covers the collateral.

Pain in a region with no tenderness in that region should raise referral from the hip or the spine. 4.2.15 covers referred pain.

How Good It Is

Location performs moderately. It narrows the differential reliably and identifies the structure poorly, because several structures share each region.

It performs best for the patellofemoral joint, where anterior pain with the characteristic provoking activities is reasonably discriminating.

It performs worst in the degenerate knee, where pain is commonly diffuse and the compartment with the worst radiographic change is not reliably the painful one.

Tenderness on examination outperforms the patient's report of location for identifying the structure, which is the opposite of the instability case.

FRCS Level

How Good It Is

The decision this question informs is which compartment to treat, and in unicompartmental disease it carries real weight.

A patient with medial radiographic change and medial pain is a candidate for a medial procedure. The same radiographs with diffuse or anterior pain are a different conversation. 4.18.3 covers varus disease.

Pain in a compartment the imaging says is normal is a reason to look again rather than a reason to dismiss the patient.

Pain in more than one compartment, in a knee being considered for a partial replacement or an osteotomy, is among the more useful predictors of dissatisfaction. 4.20.7 covers partial replacement assessment.

Where It Misleads

The commonest error is accepting a region rather than a point. Medial covers the joint line, the collateral, the pes anserinus and the posteromedial corner, and these have different treatments. 4.16.7 covers pes anserinus pathology.

The second is the leading question, which is why the one finger instruction appears on this page and on 4.2.1.

The third is ignoring the hip. Anterior thigh and knee pain from the hip is common and the knee examination will be normal.

And pain that has moved from one region to another is usually a compensation rather than a second diagnosis, which is a history finding with no imaging equivalent.

Fellowship Level

Where It Misleads

After surgery the location of pain is frequently the most useful single piece of history, because it points at what was done rather than at what was there.

Pain over a graft harvest site, a tunnel, a fixation device or a scar is attributable to the operation and is frequently reported as knee pain without qualification. 4.3.7 covers surgical scars.

Anterior pain after a reconstruction raises the harvest site, patellofemoral loading from quadriceps deficit, or a cyclops lesion, and these need separating before anything structural is pursued.

Pain at the joint line after a meniscal repair may be the repair rather than a new tear, and the timing relative to rehabilitation milestones usually settles it.

In a painful arthroplasty, the location is one of the few history features that discriminates, and diffuse pain across the whole knee is more suggestive of infection or sensitisation than of a mechanical cause. 4.20.8 covers the assessment.

No figure here supports any of these, under decision 023.