Post-operative Gait

For Medical Students

What It Tests

Watching a patient walk after a knee operation tests whether the knee has been reintegrated into the way they move, which is a later and harder milestone than range of motion or a healed wound.

The range returns first, the strength second, and the gait last. A patient with a full range and a normal laxity examination can still walk abnormally, and that is a finding rather than an inconsistency. 4.7.10 covers post-operative range.

The gait is therefore the outcome measure that corresponds most closely to what the patient means by recovery. 4.22.8 covers the scores built for that.

How It Is Performed

Watch the patient walk at every post-operative visit, before examining the knee, and over the same distance each time.

Note the stance time symmetry, which is the first thing to normalise.

Note the flexion wave in early stance, which is the last thing to normalise and the one most often still absent at discharge. 4.4.3 covers that pattern.

Note whether the knee reaches full extension at heel strike, since an extension deficit shows itself here before it is measured. 4.7.8 covers extension lag.

Note any thrust, because a thrust after a ligament reconstruction is a different and more urgent finding than a residual limp. 4.5.7 covers dynamic alignment.

What a Positive Means

A persisting antalgic pattern indicates pain, and pain at a stage where it was expected to have settled needs a cause sought rather than time given. 4.4.2 covers the pattern.

A persisting avoidance pattern indicates a quadriceps that has not recovered, which is a rehabilitation finding and the commonest one. 4.3.9 covers wasting.

A new thrust after a ligament reconstruction indicates that the reconstruction is not controlling the plane it was meant to, and it is the finding that most warrants investigation. 4.13.8 covers combined injuries.

A gait that was normal and has become abnormal is more significant than one that has never normalised, because it indicates a change rather than a lag. 4.1.8 covers the record that makes that comparison possible.

Normalisation of the gait, when it happens, is the clearest sign that the operation has worked. 4.4.1 covers the target pattern.

MRCS Level

How It Is Performed

In a viva this is the answer to how you would follow up a reconstruction, and putting the gait alongside the range and the laxity is the mark.

The expected points are the same distance each visit, before the couch examination, stance symmetry, the flexion wave, terminal extension, and any thrust.

Say that you would record it in the same terms each time, so that the comparison across visits is meaningful. 4.1.8 covers the record.

Say that you would relate it to the rehabilitation stage rather than to the weeks elapsed, since programmes differ. 4.2.34 covers previous rehabilitation.

Say that you would raise the task for an athlete, because walking is below the demand that matters and a normal walk is not a return to sport. 4.4.8 covers running gait.

What a Positive Means

The reasoning expected is that walking requires the quadriceps to control a flexing knee under load, so the gait normalises only when that control returns, which is later than the range and the graft's mechanical competence. 3.14.2 covers the stance phase.

Pain inhibits the quadriceps, so a persisting antalgic pattern and a persisting avoidance pattern are frequently the same problem seen twice. 4.8.2 covers inhibition.

A thrust requires a restraint to be absent rather than weak, so it cannot be explained by rehabilitation and always means something mechanical. 3.13.7 covers dynamic alignment.

Gait symmetry also depends on the other limb, which is relevant where a graft was harvested from it or where the other knee is also affected. 4.3.7 covers surgical scars.

How Good It Is

Post-operative gait is the outcome measure that corresponds best to the patient's experience and is recorded least often, which repeats this chapter's theme.

It is sensitive to incomplete recovery and non specific about its cause, so it prompts the question rather than answering it.

It is more useful as a series than as a single observation, which makes the first recorded post-operative gait the most valuable one.

Patient reported outcome scores capture overlapping ground more reproducibly and less immediately, and the two are complementary. 4.22.8 covers their use.

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 the post-operative gait decides whether a patient is progressing or stalled, and stalled patients need a reason found rather than more time.

A persisting avoidance pattern at a stage where the quadriceps should have recovered is a rehabilitation problem, and the answer is a programme rather than an investigation. 4.11.5 covers the assessment.

A new thrust is the exception. It is mechanical, and it means the reconstruction or the alignment needs investigating now. 4.13.4 covers the corner.

A persisting antalgic pattern with a swollen knee raises low grade infection, and in a reconstruction that has to be excluded rather than attributed to activity. 4.3.6 covers the skin.

Where the gait and the measured range disagree, the gait is the better predictor of satisfaction, which is worth knowing when a patient with a textbook range is unhappy. 4.7.10 covers the range.

Where It Misleads

The commonest error is not recording the gait at the first post-operative visit, which removes the baseline for every later comparison.

The second is attributing a persisting abnormality to time when the stage has passed.

The third is reading a thrust as a rehabilitation issue, which it never is.

The fourth is using walking as the outcome in a patient whose demand is far above it. 4.4.9 covers single leg landing.

The fifth is examining the knee before watching the walk, which is the order this whole chapter argues against. 4.3.1 covers that argument.

Fellowship Level

Where It Misleads

In referred practice the post-operative gait is usually the only objective record of how a patient was progressing, and it usually does not exist.

A patient referred years after a reconstruction with an abnormal gait and no record of their earlier one cannot be assessed for change, and that is a limit to state rather than to work around. 4.1.8 covers the record.

A patient whose gait normalised and has deteriorated has a new problem, and in a reconstructed knee that is graft failure, compartment change or a corner that has stretched. 4.4.6 covers the compartment pattern.

An athlete with a normal gait and a failed return to sport needs a higher task, and the gait contributes nothing further to that assessment. 4.23.2 covers those patients.

In the multiply operated knee an abnormal gait may be the best achievable result, and recognising that prevents a further operation offered against an unachievable target. 4.10.12 covers revision assessment.

An incompletely recovered nerve palsy produces a permanent gait abnormality that is not a failure of the reconstruction, and separating the two protects both the patient and the record. 4.13.4 covers the corner.