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KneeSchool/Imaging Academy/Reporting ACL Injuries

Reporting ACL Injuries

Page 5.20.3 · Imaging Reporting Academy · imaging page

The word complete, which the surgeon acts on and the images support least, and the findings that matter more than the grade.

Pipeline status. Editorial draft. Evidence verification did not run. Not consultant reviewed. Not for clinical use.

The same topic at 4 depths

Each tier deepens the one below it and never repeats it. Choose the level you want.

Reporting ACL Injuries

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For Medical Students

What It Shows

An ACL report states whether the ligament is intact, partially torn or completely torn, and what else was injured. 5.7.1 covers the normal ACL.

It is built from the ligament's continuity and orientation on each plane together with the secondary signs. 5.7.3 covers complete tears.

It matters because the associated injuries change the operation more often than the ACL's own grade does. 5.7.4 covers the acute ACL injury.

How It Is Acquired

Assess continuity on sagittal, coronal and axial images rather than on one plane. 5.5.9 covers the ligaments.

State the bundle involvement wherever it can be seen. 2.7.8 covers the anteromedial bundle.

Record the secondary signs of anterior translation separately from the ligament itself. 5.7.5 covers the chronic ACL injury.

Report the menisci, the collateral structures and the cartilage from the same study. 5.20.2 covers reporting meniscal tears.

Report the bone bruising pattern, which records the mechanism. 5.13.1 covers bone marrow oedema.

What Normal Looks Like

A clear statement of intact, partial or complete with the planes that support it. 5.7.1 covers the normal ACL.

The secondary signs listed as findings of their own. 5.7.5 covers the chronic ACL injury.

The associated structures each reported as intact, injured or not assessable. 5.20.4 covers reporting MCL injuries.

A bone bruising pattern described rather than merely noted. 5.13.1 covers bone marrow oedema.

A conclusion that names the injury combination rather than the ligament alone. 5.7.4 covers the acute ACL injury.

What Abnormal Looks Like

A report that says ACL tear without saying partial or complete. 5.20.8 covers common reporting errors.

Partial reported because the ligament is thickened rather than because fibres are intact. 5.7.2 covers partial tears.

Secondary signs offered as evidence for the tear and never as findings in themselves. 5.7.5 covers the chronic ACL injury.

A lateral root or ramp lesion unreported in an acute ACL study. 5.6.10 covers ramp lesions.

Mucoid degeneration reported as a partial tear. 5.7.6 covers the mucoid degeneration.

Key Learning Points

  • Intact, partial or complete is the word that gets acted on.
  • The associated injuries change the operation more often.
  • Secondary signs are findings in their own right.
  • Bone bruising records the mechanism.
  • Mucoid degeneration is mistaken for a partial tear.

MRCS Level

How It Is Acquired

In a viva the expected answer reports the knee rather than the ligament.

The expected points are continuity on three planes, the partial or complete distinction, the secondary signs, the associated injuries, and the bruising pattern.

Say that partial is the least reproducible word in the report. 5.7.2 covers partial tears.

Say that the examination carries the functional question and the scan carries the structural one. 4.14.1 covers the pivot shift.

Say that an ACL study is a whole knee study. 5.5.2 covers the sports knee protocol.

What Abnormal Looks Like

The reasoning expected is that a ligament can be structurally continuous and mechanically incompetent, which is why the scan cannot replace the examination. 3.7.3 covers the secondary restraints.

A complete tear is reported from discontinuity with a change in orientation, and the secondary signs add confidence rather than making the diagnosis. 5.7.3 covers complete tears.

The associated injuries define the operation, so a report stopping at the ACL is incomplete rather than wrong. 5.7.4 covers the acute ACL injury.

A chronic tear has lost the secondary signs the acute one had, so the appearance depends on the interval. 5.7.5 covers the chronic ACL injury.

How Good It Is

Magnetic resonance reporting of a complete ACL tear is the most reliable ligament reporting in the knee, and reporting of the partial tear is among the least.

Its best contribution is the complete tear with the associated injury list. 5.7.3 covers complete tears.

It is limited by the partial category, by mucoid degeneration, and by the functional question it cannot address. 5.7.6 covers the mucoid degeneration.

No figures appear for accuracy on this page, under decision 028, and no agreement statistics for the partial category appear either: those are published quantities from particular reader panels and this environment cannot check them.

Key Learning Points

  • A continuous ligament can be mechanically incompetent.
  • Secondary signs add confidence rather than make the diagnosis.
  • A report stopping at the ACL is incomplete.
  • The appearance depends on the interval since injury.
  • Partial is the least reliable word available.

FRCS Level

How Good It Is

At decision level the report's job is to list what will be dealt with at the same operation. 5.17.1 covers the ACL reconstruction.

A ramp lesion or a lateral root tear changes the operative plan and the consent. 5.6.9 covers root tears.

A posterolateral or posteromedial injury alongside the ACL changes the operation entirely. 5.20.4 covers reporting MCL injuries.

The chondral surfaces carry part of the prognosis and belong in the conclusion. 5.20.5 covers reporting cartilage lesions.

Partial is a word to avoid unless the report states which fibres are intact and on which images. 5.7.2 covers partial tears.

Where It Misleads

The commonest error is reporting a partial tear from a thickened ligament in an older knee. 5.7.6 covers the mucoid degeneration.

A ganglion cyst within the ligament is reported as a tear. 5.7.7 covers the ganglion cysts.

A chronic tear with no secondary signs is read as an intact ligament. 5.7.5 covers the chronic ACL injury.

A healing ligament is reported against an intact reference that no longer applies. 5.7.8 covers the ACL healing.

The report names the ACL and the examination finds the rotational instability nobody looked for. 4.14.3 covers the anterolateral rotatory instability.

Key Learning Points

  • A thickened ligament in an older knee is not a partial tear.
  • A ganglion within the ligament mimics a tear.
  • A chronic tear loses the signs that made the acute diagnosis.
  • Healing has no agreed reference appearance.
  • Rotational instability is a clinical finding rather than a reported one.

Fellowship Level

Where It Misleads

At fellowship level the scan and its report usually precede the referral, and the revision question differs from the one they answered. 5.7.14 covers the revision ACL imaging.

Graft appearance changes for a long time after reconstruction, so a report of graft failure needs the interval to mean anything. 5.7.10 covers the graft maturation.

Tunnel position is the finding that decides a revision and the one most often absent from the report. 5.7.12 covers the tunnel assessment.

A report written for a primary injury is reused for a revision assessment it was never designed for. 5.20.7 covers reporting the post-operative knee.

Automated ACL reporting performs best on the complete tear, which was already the easy part. 5.18.8 covers artificial intelligence in imaging.

The useful report gives the ligament, the secondary signs, the whole associated injury list, the tunnel positions where relevant, and the interval since injury or surgery. 5.20.1 covers structured reporting.

Key Learning Points

  • Graft reporting needs the interval to mean anything.
  • Tunnel position decides a revision and is often unreported.
  • A primary report is reused for a revision question.
  • Automation is strongest where reading was already reliable.
  • The report should state the interval since injury or surgery.

Explore Further

Where this topic came from and where it goes next in the spiral.

References

No reference list is attached to this draft. Evidence verification has not run, because source retrieval was unavailable at generation time. Under the Operations Handbook a missing reference is acceptable and an invented one is a critical failure, so nothing has been cited and no citation marker appears in the text. This page carries no diagnostic accuracy figure, which is decision 028 rather than an omission: the comparative standing of the modalities is standard teaching and a specific sensitivity written from memory is the same class of claim as an invented citation, so ACC-001 refuses the number and the page states the comparison. A reviewer with the literature can add the figures into How Good It Is without restructuring the page. Any measurement here, including a sequence parameter, an angle or a millimetre, is written from standard teaching, has not been checked, and is registered under decision 006 in pipeline/config/figures with a verification state of UNVERIFIED_FROM_MEMORY.

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