When to order an investigation for a suspected ACL injury?

[physiobob]

Thanks for that post. Fair point. I think in many cases the ACL undergoes repeated injury. Only perhaps a good first time injury would give the significant effusion. But who knows.

I suppose it's interesting that the MRI in your case might not have provided any more assistance than the clinical observation. Thoughts? Perhaps only refer for MRI if you have the direct intention of a surgical intervention at that time. If you initial intention is conservative management then wait until that either fails or succeeds? What do you think?

[roycar]

Where conservative management is possible I always try it, definitely. It's really all down to the client's wishes. If someone is happy to rehab the knee and probably avoid sports with rotatory forces on the knee etc I'm not going to be pushing for an MRI or surgical option. Obviously then if this fails further investigation is warranted.

On the other hand if someone presents to me with an objectively deficient ACL +/- episodes of instability and wants to get back so a higher level of for example, football, but is unwilling to have surgery I'l just go through the facts with them, the possibility of further injury etc and let them make in informed decision.

From talking to a number of specialised knee orthopods it seems to me that the importance placed on MRI's varies quite a lot. What does seem clear enough is that it is quite difficult to ascertain the actual level of damage to the ACL from an MRI. 20% 30% 50% tear etc. Even more difficult is equating the level damage to, say, the level of instability. It's possible for someone to have a 50% tear with a fairly stable knee but for someone else to be having recurrent episodes of instability. This may be to do with the exact area of damage and the different orientation of fibres in the ACL and their different roles in knee stability or may be to do with extrinsic controls eg quads strength/control etc. MRI can be used to confirm whether the ACL has been damaged further information is limited. In my case, my Ortho surgeon did not look at my knee scans and indeed did not even read the report. He checked my lachmans and anterior drawer. Attempted a pivot shift (that i was too apprehensive for him to go ahead with!) Asked what my problem was ( a number of times when i felt unstable and a number of actual episodes of instability with turns when running) and we agreed that a scope plus more than likely a repair was necessary.

So in short, yes, the MRI gave very little insight into my knee injury other than to confirm that the ACL was involved in some way. It was my subjective reports, the objective ACL tests and my wish to return to sports where twisting/turning is commonplace that were taken into account.

It would be interesting to know of other peoples experiences regarding this. Are surgeons interested in MRI results or are they proceeding with the surgical option on mainly clinical findings?