Why Clinical Examination Matters

For Medical Students

What It Tests

An examination of the knee tests what the joint does. Imaging shows what its tissues look like. Those are different questions and they have different answers in the same patient.

A torn structure on a scan may be doing its job. An intact structure on a scan may be failing. Examination is how you find out which.

It also tests something no scan reaches: what this person can tolerate, how they move, and what they are guarding against.

That is why examination survived the arrival of imaging rather than being replaced by it.

How It Is Performed

The sequence is always look, feel, move, then test, and the order is not arbitrary.

Looking before touching tells you where the knee is held and what it will not do, which changes how you then touch it.

Feeling before moving localises the problem to a structure while the patient is still relaxed.

Special tests come last, because every one of them is uncomfortable and an uncomfortable patient guards. A guarded knee reads normal when it is not. 4.1.4 covers the full sequence.

What a Positive Means

A positive test means the finding was present, not that the diagnosis is made.

Each test interrogates a motion and a structure, and a positive licenses a conclusion about that motion and no more.

Findings combine. One positive test with a matching history is worth more than three positive tests that do not agree with each other or with what the patient describes.

MRCS Level

What a Positive Means

In examination terms a positive finding shifts a probability rather than settling a question, which is the framing an examiner is listening for.

A knee is assessed by building a picture: a mechanism, a symptom pattern, a set of findings, and the degree to which they agree.

Disagreement between those four is information rather than a nuisance. A patient describing instability with no laxity on examination has something going on that neither the history nor the test explains alone.

How Good It Is

Knee examination is better than its reputation for some questions and worse for others, and the pattern is consistent enough to learn.

It is strong for cruciate integrity. The Lachman test is the most reliable single manoeuvre in the knee and outperforms the anterior drawer substantially. 4.10.4 covers it.

It is weak for meniscal tears. The standard meniscal tests are specific rather than sensitive, so a positive is informative and a negative is close to useless. 4.9 covers them.

It is moderate for cartilage and poor for the source of anterior knee pain, where no test reliably localises the problem.

No figures appear anywhere in Section 4 for these claims, under decision 023, because the comparison is standard teaching and a quoted percentage written from memory is not.

FRCS Level

How Good It Is

At this level the question is not whether examination works but what it is being asked to do in a particular decision, and the answer changes its value.

Examination is at its most valuable where imaging is ambiguous and a decision depends on function: a degenerate knee with a scan full of findings, a post-operative knee, a knee whose symptoms do not match its images.

It is at its least valuable where the lesion is structural, the imaging is definitive and the decision follows from the anatomy.

A test's accuracy also depends on who is performing it and on when. Laxity tests read differently in the acute knee, under anaesthetic, and at three weeks, and the same test in the same knee gives different answers at those three points. 4.20 covers the post-operative version of the problem.

Where It Misleads

The commonest error in knee practice is not a missed finding. It is treating an image as the answer to a question only the examination asked.

A degenerate meniscal tear is present on a large proportion of asymptomatic middle aged knees, so finding one on a scan does not make it the cause of this patient's pain. 4.9.11 covers the consequence.

The reverse error is less common and more costly. A normal scan in a patient describing mechanical symptoms does not exclude a cause, and the examination is what distinguishes them.

The third error is institutional rather than individual. An examination done badly is worse than one not done at all, because a recorded normal finding is believed by everyone downstream and is rarely repeated.

Fellowship Level

Where It Misleads

At fellowship level the examination's role changes again. It is now mostly being used to decide whether a previous conclusion was right.

A revision assessment is an examination problem rather than an imaging one, because the images will be full of the previous operation and the question is what the knee now does.

Three patterns recur in referred patients. Rotational laxity missed because only anterior translation was tested. A posterolateral corner injury missed because the dial test was not done at two flexion angles. And a patellofemoral cause attributed to a tibiofemoral finding that happened to be visible on a scan.

All three are failures of examination completeness rather than of technique, which is why this section is organised by region and insists on a sequence.

The honest limit is that examination under anaesthetic remains the most informative single assessment of laxity available, and it requires an anaesthetic, which means the decision to use it is itself a judgement rather than a step in a protocol.