The menisci are cartilage “shock-absorbers” within the stifle joint, and are vulnerable to damage when the stifle is unstable. There are surgeons who regard meniscal injuries as insignificant, and some surgical procedures for cruciate disease (e.g. MMP) are commonly carried out without a stifle arthrotomy.
We believe that medial meniscal injuries are commonly significant and as such perform an arthrotomy as part of nearly every TPLO procedure that we perform, to inspect the menisci and treat any meniscal injuries that are identified. Proper inspection of the medial meniscus requires good retraction, instrumentation and illumination. We have seen several dogs that have recovered poorly after cruciate surgery performed without an arthrotomy, and seen these dogs improve following an arthrotomy and treatment of the meniscal injury.
“Late” meniscal injuries (e.g. post-op) are an occasional problem in dogs that have had previous surgery for cruciate injury. The meniscus is seen to be undamaged at the first surgery but subsequently becomes damaged. This generally presents as an acute onset of fairly severe lameness in the operated leg a few weeks or months after surgery. In the absence of any other cause, an exploratory arthrotomy is indicated in these dogs to check and treat the menisci as necessary. The rate of late meniscal injuries is generally about 3-5%.