Re: Meniscal Release

Malcolm Ness — Wed, 27 Jan 2010 11:15:59 GMT

Hi Stuart,

Meniscal release is one of the most controversial topics in SA orthopaedics.

The term refers to the practice of deliberately cutting the medial meniscus (between the medial and caudal ligaments) as part of cruciate surgery.

The technique was first reported by Dr Barclay Slocum (he who developed TPLO) who observed that the most common reason for his TPLO cases representing lame was late meniscal injury. He reasoned that this was due to persisting stifle instability and hypothesised that cutting the meniscus might reduce the incidence of this complication. Barclay reported a big case series which supported this contention and my experience is similar.

Meniscal release can be used with the same justification in any cruciate surgery. No currently available technique actually restores normal motion or stability to the stifle so some motion under load is inevitable no matter how stable the stifle feels in your hand. I have taught meniscal release as part of fabello-tibial cruciate surgery for at least 10 years now.

The "antis" argue that the meniscus is an essential part of a healthy joint and that it is intuitively wrong to injure an existing normal bit of the anatomy. Experimental evidence is cited to show that cutting a normal meniscus in a normal joint causes pathology. However, good clinical evidence to show that meniscal release in an already diseased joint (cruciate deficient!) causes additional pathology over what we are expecting as a result of the failed cruciate, is still lacking. Some surgeons like to extrapolate human meniscal research but ignore the fact that the canine and human meniscus are quite different - for example, spontaneous and isolated meniscal injury is common in people and almost unknown in dogs.

So, to release or not to release, that is the question. Personally, I release almost every case I operate because I don't like to reoperate cases due to late meniscal injury and, try as I might, I can't see that the procedure is doing any harm. However, I recognise that it is a theoretically "wrong" thing to be doing and I would not take issue with surgeons who choose to leave intact menisci alone. As far as "tidying up" an already damaged meniscus, I think that is a waste of time and I would release in every case - my understanding of how the meniscus works indicates that its function depends on anatomical integrity and even a small amount of damage will significantly impair its function.

There is a pressing need for canine specific research on the meniscus but until then, you look at what evidence there is and make a decision - sound in the knowledge that you might have to change your mind further down the line.

Malcolm N