Why did my ACL reconstruction fail?

Failure is often more than one thing

Surgeons usually group the causes into three areas: something about the operation, something about the knee itself, and something about what happened afterwards. In many patients two or three factors combine, which is why a revision is planned around the individual knee rather than simply repeating the first operation.

Factors linked to the first operation

• Tunnels placed too vertically or too far forward, so the graft does not control rotation
• A graft that was small in diameter or did not heal well into the bone
• Fixation that loosened before the graft had incorporated
• An injury to another structure, such as the posterolateral corner or the medial ligament, that was not treated at the time

Factors linked to your knee and activity

Some knees put more strain on an ACL graft than others. A steep backward slope on the top of the tibia, bow legs, a missing or torn meniscus and generalised joint laxity all increase the load the graft must resist.

Timing also matters. Returning to football, padel or basketball before strength and control tests are passed is linked to a higher risk of re-injury, especially in younger athletes. A new, high-energy injury can tear even a well-placed graft.

How Dr. Gelber investigates a failed graft

The assessment usually combines a full ligament examination, a new MRI, a CT scan of the tunnels and, when slope or alignment may be involved, long-leg X-rays. Your previous operation notes tell him which graft and fixation were used. Together these show whether a one-stage revision is possible and which additional procedures, such as a lateral extra-articular reinforcement, may protect the new graft.