Pivot Shift Literature

For Medical Students

What the Question Was

The question was how to detect the rotational instability a cruciate deficient knee produces, since the anterior tests measure translation in one direction only. 4.10.4 covers the Lachman test.

The answer had to reproduce the event the patient describes, which is the knee giving way during a turn rather than sliding forwards. 4.2.6 covers giving way.

Several manoeuvres were described to do that, and they share a mechanism while differing in how the knee is held and loaded. 4.10.6 covers the pivot shift test.

What It Showed

The work established that the rotational event can be reproduced by hand, and that reproducing it is strong evidence of a cruciate deficient knee.

It also established that the test needs a relaxed patient, which is why it is often uninterpretable in the acute knee. 4.23.1 covers the examination under anaesthesia.

It did not produce agreement on grading, so the result is usually recorded as present or absent rather than graded. 4.1.8 covers examination documentation.

MRCS Level

What Was Done

Galway and MacIntosh described the manoeuvre that gave the phenomenon its clinical name, applying valgus and rotation to a knee moving from extension into flexion. 4.10.6 covers the technique.

Losee and Jakob described variants that load the knee differently, and the existence of several variants is itself informative about how hard the finding is to elicit. 4.14.1 covers the rotational examination.

Comparative accuracy work set the rotational tests against the anterior tests and against operative findings.

Instrumented and image based measurement of the shift followed, attempting to replace a graded hand finding with a measured translation.

Examination under anaesthesia established how much of the test's failure rate is guarding rather than an absent lesion. 4.23.1 covers that examination.

What It Showed

The comparative work established that the pivot shift is specific and insensitive, which is the opposite profile from the Lachman and the reason both are performed. 4.10.4 covers the Lachman test.

It established that the test's sensitivity rises substantially under anaesthesia, which identifies guarding as the limiting factor rather than the lesion. 4.23.1 covers that examination.

It established that interobserver agreement on grading is poor, which is why the grade travels badly between clinics. 4.1.8 covers examination documentation.

No sensitivity, specificity or likelihood ratio appears on this page, under decision 023 and decision 022 together. The ranking is what is recalled reliably; a specific percentage written from memory would look exactly like a correct one.

FRCS Level

What It Showed

At decision level the test's profile is what makes it useful, because a positive result is close to decisive and a negative one is close to uninformative.

A positive pivot shift in an awake patient is strong enough to act on, which is the practical consequence of high specificity. 4.10.6 covers the test.

A negative pivot shift in an awake patient says little, which is why it never excludes a cruciate injury. 4.2.6 covers giving way.

The rotational examination's relationship to the anterolateral structures was established by the same body of work, which is why a high grade shift raises them. 4.14.3 covers anterolateral rotatory instability.

Instrumented measurement improved reproducibility and has not displaced the hand test, because the quantity it measures is not the quantity being judged. 4.2.2 covers instability.

What It Changed

It made the rotational examination a standard part of the cruciate assessment rather than an advanced extra. 4.10.6 covers the test.

It made a positive result in an awake patient actionable, which changes the imaging threshold rather than replacing the imaging. 4.1.6 covers that relationship.

It made examination under anaesthesia the accepted route to the finding when the awake test fails. 4.23.1 covers that examination.

It raised the anterolateral structures as a clinical question, which changed the operation in some patients. 4.14.3 covers anterolateral rotatory instability.

Fellowship Level

What It Changed

At fellowship level this literature's legacy is a test everyone performs and nobody grades the same way.

The grade is used in decisions about adding an anterolateral procedure, and the grade is the least reproducible quantity in the section, which is an uncomfortable combination. 4.14.3 covers anterolateral rotatory instability.

The post reconstruction pivot shift is the finding used to judge rotational control, and it inherits the same reproducibility problem. 4.20.1 covers the reconstruction assessment.

The relationship between a residual shift and a patient's reported instability remains loose, so the test and the symptom are recorded separately. 4.2.2 covers instability.

Measurement under anaesthesia is reproducible and measures the knee the patient does not use, which is the trade this literature never resolved. 4.23.1 covers that examination.

What to Read Now

Chapter 3.17 carries the biomechanical work on pivot shift mechanics, which is the explanation behind the clinical finding.

The comparative accuracy literature is where this page's omitted figures belong, and they can be added into 4.10.6 by a reviewer with access. 4.10.6 covers the test.

The instrumented measurement literature is the reading for anyone weighing a quantified shift against a graded one.

The anterolateral complex literature is the reading for the procedure question. 4.14.3 covers anterolateral rotatory instability.

No reference list appears on this page. No source was retrieved, and under decision 022 a named author with a described finding is the most this process can honestly supply, with no year, journal or citation attached.