I again hit the plenary session today.  I’m only going to talk about one of the abstracts presented, and that’s the last one by Dr. Englund.  He looked a knee MRIs in a community population and found that tears or maceration (destruction) of the meniscus – the ‘padding’ of the knee joint, if you will – are common.  Something like 1 in 4 knees had meniscal injuries, and the prevalence was something like 50% in people over 55 (I’ve got the numbers wrong, but it’s something like that).  Meniscal injury was associated with osteoarthritis (OA) – not surprising really.  If the joint is narrow and ratty, then maybe it causes meniscal damage.  On the other hand, maybe the meniscal damage causes OA.

But what was very interesting, is that after controlling for OA, there was no association of pain with meniscal injury.  This flies in the face of current thinking by most orthopedic surgeons who often assume that a meniscal tear must be causing pain.  Therefore they do surgery to repair or remove it.  We know that this can accelerate osteoarthritis, but it’s justified because it’s assumed the meniscal damage causes pain.  Dr. Englund’s study strongly suggests that that’s not the case, and that meniscal damage is very common – and therefore will be found in lots of patients if you look for it – but is probably NOT causing significant pain.  Therefore, operating on meniscal tears may not only be unnecessary but, because removing the meniscus can accelerate OA, may actually be harmful.

This is a very important result and may change how we manage patients with meniscal injuries in the future.  It also means that we probably shouldn’t think too much of an MRI that shows damage.