Meniscal Examination in OA

For Medical Students

What It Tests

In a degenerate knee the meniscal tests are being asked a question they cannot answer, and knowing that is more useful than performing them better.

Degenerate meniscal tears are common in knees with no symptoms attributable to them, so finding one does not make it the cause.

The examination's job in this knee is therefore to establish whether there is a mechanical problem on top of the degeneration, which is a narrower and more answerable question.

How It Is Performed

Take the history for a mechanical symptom specifically, and distinguish a true block from a catch and from pain. 4.2.5 covers locking.

Examine for a mechanical block as the priority, because that is the finding that would change management. 4.9.8 covers it.

Assess alignment and range, which describe the degenerative knee and are both recordable and comparable. 4.5.1 and 4.7.1 cover them.

Palpate the joint lines, expecting tenderness and recording whether it is localised or diffuse.

Perform the provocative tests if you wish, understanding that a pain-based positive in this knee carries little information.

What a Positive Means

A confirmed mechanical block in a degenerate knee is still a mechanical problem and is still an indication, and this is the main exception the page exists to state.

Localised tenderness at one point with a matching mechanical symptom is more informative than diffuse tenderness with activity-related pain.

Diffuse tenderness, an effusion after use, stiffness after rest and a reduced range describe degenerative disease rather than a symptomatic tear. 4.18.2 covers established disease.

A positive provocative test in this setting is weak, because forced rotation provokes pain in a degenerate joint regardless of whether a tear is present.

MRCS Level

What a Positive Means

The reasoning expected is about base rates and about what the trials actually tested.

Degenerate meniscal change is common in asymptomatic middle aged knees, so the scan finding has limited weight on its own. 4.1.6 covers the point.

Randomised trials comparing arthroscopic partial meniscectomy with physiotherapy or with a sham procedure in degenerate knees with mechanical symptoms found no advantage for surgery. 3.17.3 covers them.

Those trials recruited mechanical symptoms rather than mechanical blocks, which is the most important thing to know before quoting them in either direction.

So the honest position is that they settle the degenerate tear with pain and catching, and do not settle the degenerate tear with a true block.

How Good It Is

Every test in this chapter performs worse in a degenerate knee, and the reasons are consistent.

Joint line tenderness is near universal, so its specificity collapses.

The provocative tests rely on pain, and a degenerate joint hurts on forced rotation whatever its meniscus is doing.

The weight bearing tests are frequently impossible, because the patient cannot squat.

The one finding that holds is a mechanical block, and that is the whole reason the examination is still worth doing in this population. 4.9.8 covers it.

No figures appear, under decision 023.

FRCS Level

How Good It Is

At decision level this page carries the chapter's most consequential conclusion: in a degenerate knee, the examination exists to find the exception rather than to confirm the rule.

The rule is that a degenerate tear with activity-related pain is managed non-operatively, and the evidence for that is as good as anything in knee surgery. 3.17.3 covers it.

The exception is a true mechanical block, which remains surgical.

The second exception is a symptomatic tear in a knee with otherwise preserved cartilage and well localised findings, where the tear may genuinely be the problem, and the examination is what identifies that patient.

Everything else in this knee is a load and function problem, and the assessment is alignment, range, function and comorbidity. 4.18.6 covers functional limitation.

Where It Misleads

The commonest error in the whole of knee practice is arthroscoping a degenerate knee for pain on the strength of a tear on a scan, and 4.1.1 names it as such.

The second is the mirror image: refusing an operation to a patient with a genuine block because the knee is degenerate and the trials exist.

The third is quoting those trials as a verdict on arthroscopy generally, when they are a verdict on one procedure in one population. 3.17.3 covers the distinction.

And attributing all of a degenerate knee's symptoms to the one finding that can be operated on, which is a bias of the available intervention rather than of the evidence.

Fellowship Level

Where It Misleads

In referred practice this presentation is the one where saying no is the service being provided, and the examination is what makes saying no defensible.

A patient arriving with a scan, a tear and an expectation of arthroscopy needs an examination that establishes the absence of a block, the presence of degenerative findings, and the localisation of their symptoms, and then needs that explained.

The conversation is easier when the examination has been done properly, because a recorded absence of a mechanical block is a reason rather than an opinion. 4.1.8 covers the record.

The patient who does need an operation in this group is identified by the same examination, which is why performing it carefully matters as much here as anywhere.

The chapter's closing point is that eleven pages of meniscal tests lead to one finding that acts alone, a combination that is better than any single test, and a population in which the whole group performs poorly. That is an honest summary of a widely taught examination and it is not how it is usually taught.

No figure here supports it, under decision 023.