Post-Reconstruction Assessment

For Medical Students

What It Tests

Examining a reconstructed knee tests whether the graft is doing its job, and also tests three things that are commonly wrong when the graft is intact.

Range of motion, quadriceps function and the harvest site are all possible sources of a disappointing result in a knee with a sound graft.

So the examination here is broader than a laxity test, and the sequence changes: range and extensor function come before laxity. 4.1.4 covers adapting the sequence.

How It Is Performed

Assess extension first and compare with the other side, because a loss of extension after reconstruction is the finding most worth catching early. 4.7.10 covers post-operative range.

Assess flexion, and characterise the end feel, because a developing contracture is invisible if only the range is recorded. 4.7.5 covers end feel.

Assess quadriceps bulk and function, including a straight leg raise and a single leg squat. 4.21.1 covers the squat.

Palpate the harvest site, the tunnels where palpable, and the scars. 4.3.7 covers surgical scars.

Then perform the Lachman and the pivot shift, comparing with the other side and with the pre-operative record if one exists. 4.1.8 covers the record.

What a Positive Means

A firm endpoint with slightly increased translation compared with the other knee is a satisfactory graft, not a failure. 4.10.4 covers the Lachman.

A soft endpoint indicates graft failure and is the finding that matters.

A persisting pivot shift with a satisfactory Lachman indicates a rotational problem rather than a graft problem, and is this chapter's recurring theme. 4.10.9 covers it.

A loss of extension with a hard endpoint raises a cyclops lesion, which is treatable and frequently recorded as stiffness instead. 4.9.8 covers mechanical blocks.

Anterior pain at the harvest site, worse on kneeling, is a harvest site problem rather than a knee problem. 3.7.18 covers the patellar tendon graft.

MRCS Level

How It Is Performed

In a viva the expected order for a reconstructed knee is range, extensor function, then laxity, and the candidate is marked on knowing why.

Say that a loss of extension is time-critical and that a contracture becomes harder to treat the longer it is present.

Say that you would compare the laxity with the pre-operative record and with the examination under anaesthesia if one was performed. 4.10.10 covers it.

Say that you would assess the donor site specifically, because harvest site morbidity is a recognised cause of a disappointing result with a sound graft.

What a Positive Means

The reasoning expected is that a graft is not a ligament and should not be expected to behave like one.

A graft remodels, and its stiffness changes over the first year, so an examination at six weeks and at a year are measuring different things.

Slightly increased translation with a firm endpoint is the expected result of a successful reconstruction, and recording it as a grade one Lachman without the endpoint invites a later clinician to call it a failure.

A progressive increase across visits is the finding that indicates a stretching graft, and it is a trajectory rather than a single result. 4.1.8 covers the record that makes the comparison possible.

Rotational control is a separate achievement from translational control, so the pivot shift has to be assessed separately. 4.10.6 covers it.

How Good It Is

The post-operative examination performs well for graft integrity and less well for everything the patient is complaining about.

The Lachman test is the main clinical measure of the graft and is reliable in a comfortable, non-guarding knee, which most reconstructed knees are by review.

The pivot shift remains insensitive awake, so a rotational problem can be missed after reconstruction for exactly the same reason it was missed before it. 4.10.9 covers the gap.

The functional assessment outperforms the laxity assessment for predicting return to sport. 4.21.7 covers return to sport testing.

No figures appear, under decision 023.

FRCS Level

How Good It Is

At decision level the post-operative examination separates four causes of a disappointing reconstruction, and only one of them is the graft.

Graft failure, indicated by a soft endpoint and increased translation.

An unaddressed rotational component, indicated by a persisting pivot shift with a satisfactory Lachman. 4.10.9 covers it.

A stiffness or extensor problem, indicated by a loss of extension, a poor end feel or a quadriceps deficit. 4.7.10 covers range.

And a confidence or rehabilitation problem, indicated by a stable knee with poor dynamic performance, which is the largest of the four groups. 4.22.6 covers the instrument.

Identifying which of the four determines whether the next step is an operation, a release, a rehabilitation programme or a conversation, and the examination is what separates them.

Where It Misleads

The commonest error is recording a grade one Lachman as a failure, when a small increase with a firm endpoint is the expected result.

The second is assessing laxity and not rotation, which repeats the pre-operative error after the operation.

The third is attributing anterior pain to the joint when it is the harvest site, which is distinguishable by where it is and by whether kneeling provokes it.

And treating a loss of extension as stiffness to be rehabilitated when it has a hard endpoint and is a cyclops lesion. 4.9.8 covers the endpoint.

Fellowship Level

Where It Misleads

At this level the post-operative examination's main limitation is the absence of a pre-operative comparator, which is a records problem rather than a clinical one.

A knee with increased translation and no pre-operative measurement cannot be said to have a stretched graft rather than a graft that was always like that.

A knee with a pivot shift and no pre-operative pivot shift grade cannot be said to have a new rotational problem. 4.10.9 covers why that matters.

The practical remedy is prospective: record the examination under anaesthesia at the time of the reconstruction, with grades, endpoints and angles, because that is the comparator every subsequent examination needs. 4.10.10 covers it.

That remedy helps the next patient rather than this one, which is an uncomfortable thing to say in a clinic and is still the honest position.

No figure here supports these claims, under decision 023.