Functional Assessment

For Medical Students

What It Tests

The functional assessment of a cartilage lesion asks what the patient cannot do and at what load, which is the question treatment is offered to answer.

It matters more in this chapter than in any other, because the lesion is visible on imaging and invisible to the examination, so the functional limitation is the only evidence the lesion matters. 4.17.5 covers that argument.

The tasks are the loaded ones: stairs, squatting, descending, and for an athlete running and landing. 4.7.9 covers functional range.

How It Is Performed

Ask what the patient cannot do, specifically, and at what point in the activity it fails. 4.2.11 covers aggravating factors.

Watch them walk, and watch for an antalgic pattern or a thrust. 4.3.2 covers gait observation.

Watch a double leg squat and a single leg squat, noting whether the pain appears at a particular depth, since that corresponds to the loaded flexion angle. 4.4.9 covers single leg landing.

Watch a step down, which is the task most patients name. 4.7.9 covers functional range.

Assess the quadriceps and the proximal control, since both affect the load reaching the lesion. 4.3.9 covers muscle wasting.

Record which tasks were attempted and which were completed, rather than a summary. 4.1.8 covers the record.

What a Positive Means

Pain at a reproducible depth in a squat corresponds to the lesion being loaded at that flexion angle, and that match is the most convincing finding available. 4.7.6 covers the arc.

An inability to complete a loaded single leg task indicates a functionally significant problem, whatever the imaging shows.

A patient who completes every task without pain has a lesion that is not currently limiting them, and treating it is treating the image. 4.17.5 covers it.

An antalgic pattern or a thrust in gait indicates a loaded compartment and changes the assessment towards alignment. 4.5.7 covers dynamic alignment.

A wasted quadriceps indicates duration and is the modifiable part of the picture. 4.3.9 covers wasting.

MRCS Level

How It Is Performed

In a viva this is the answer to how you would decide whether a cartilage lesion needs treating, and the loaded tasks are the assessment.

The expected points are the specific functional history, the gait, the squats, the step down, the quadriceps and the proximal control, and the record of the tasks.

Say that the imaging cannot say whether a lesion matters and that the functional assessment can, which is the division. 4.1.6 covers it.

Say that the depth at which the pain appears should correspond to the lesion's position, which is a check worth making. 4.7.6 covers the arc.

Say that you would establish what rehabilitation has been completed, since a wasted quadriceps changes what any procedure achieves. 4.2.34 covers previous rehabilitation.

What a Positive Means

The reasoning expected is that a defect is loaded at the flexion angle at which its position comes into contact, so the depth of a painful squat localises it. 3.5.4 covers the effects of flexion.

Loaded single leg tasks multiply the load through one compartment, which is why they expose a lesion that walking does not. 3.3.11 covers kinematics during squatting.

Quadriceps strength absorbs load before it reaches the joint surface, which is why a weak quadriceps makes a lesion more symptomatic and why strengthening is part of the treatment. 3.5.3 covers load distribution.

Alignment determines the compartment's share of the load, which is why a thrust or a malaligned limb changes the whole assessment. 3.5.6 covers the effects of malalignment.

How Good It Is

The functional assessment correlates with the patient's complaint better than any other part of this chapter, and it is less reproducible between examiners.

Its most specific contribution is the correspondence between the painful depth and the lesion's position, which is an underused check. 4.7.6 covers it.

It cannot grade the lesion and does not need to, since the decision is about the limitation rather than the appearance. 4.17.5 covers that argument.

Patient reported outcome scores capture the same ground more reproducibly and belong alongside it. 4.22.2 covers one of them.

No figures appear for any accuracy comparison on this page, under decision 023, and the comparison is the claim being made.

FRCS Level

How Good It Is

At decision level this assessment is the decision, which is unusual and specific to this chapter.

A functionally limited patient with a matching lesion, a corrected or correctable alignment and an intact meniscus is the group in which a cartilage procedure has its best case. 4.17.5 covers it.

A patient with a lesion and no functional limitation is observed, and the examination is what establishes that. 4.17.1 covers the presentation.

A patient whose limitation is driven by a wasted quadriceps rather than by the lesion needs rehabilitation first, and the distinction is made by the strength and the task performance together. 4.3.9 covers wasting.

A patient whose limitation does not correspond to the lesion's compartment or flexion angle needs the source reconsidered rather than the lesion treated. 4.7.6 covers the arc.

Where It Misleads

The commonest error is offering a procedure on the imaging without a functional assessment.

The second is accepting a functional limitation without checking that it corresponds to the lesion.

The third is attributing a limitation to the lesion in a patient with a wasted quadriceps and no rehabilitation.

The fourth is omitting the alignment and the meniscal status, both of which determine whether a procedure survives. 4.9.10 covers the second.

The fifth is recording a summary rather than the tasks attempted and completed. 4.1.8 covers the record.

Fellowship Level

Where It Misleads

In referred practice this assessment is the one that was not done before the operation that did not work.

A patient with a resurfaced compartment, an unchanged functional limitation and no pre-operative functional record cannot be assessed for change, which is a limit to state rather than work around. 4.1.8 covers the record.

A patient whose limitation was always a strength problem had a surface treated and a muscle left, and the limitation persists. 4.3.9 covers wasting.

A patient whose functional limitation corresponds to a different compartment had an incidental lesion treated. 4.17.5 covers that error.

An athlete whose clinic tasks are normal and who cannot return to sport needs the assessment raised to the sport's demand, which the clinic cannot supply. 4.21.7 covers return to sport testing.

In medicolegal work the functional assessment is the part a claim concerns and the part least often recorded, which is the gap in most of these cases. 4.23.7 covers that setting.