How do I know if my ACL graft has torn?

What the examination looks for

Dr. Gelber compares the operated knee with the other one. The Lachman test measures how far the shin bone moves forward, and the pivot-shift test checks whether the knee slips when it is rotated, which is what patients feel as giving way. He also tests the medial, lateral and posterior ligaments, because a missed injury elsewhere can make an intact graft fail.

A graft can be fully torn, partly torn or intact but stretched. The examination helps tell which, and how much that matters for your knee.

What MRI adds after previous surgery

MRI shows whether the graft fibres are continuous, and it also shows the meniscus, cartilage and bone bruising from a new injury. After reconstruction the graft can look different from a native ligament for some time, and screws or staples may create artefacts. For that reason the MRI is read alongside the examination rather than on its own.

Extra tests when revision is likely

• A CT scan to measure the old tunnels, their position and any widening
• Long-leg standing X-rays if bow legs or knock knees may be loading the graft
• A lateral X-ray to measure the slope of the top of the tibia
• Instrumented laxity measurement in some cases, to compare both knees

When to book an assessment

Book a consultation if your operated knee gives way, swells after sport or feels less stable than before. Bring your previous MRI images on disc, operation notes and the rehabilitation report if you have them. Seek urgent care for a knee that is locked, hot and red, or too painful to bear weight.