Will lidocaine patches destroy the joint cartilage when applied to the knee/tibial plateau? or does that only occur with articular injections?

No, the lido only--: -penetrates superficially. also small doses of lido, or Marcaine injected into the knee along with a steroid does not effect the joints. the main complications with the caines, is from pain pumps that allows continuous flow into a joint. mainly has been seen in shoulder surgery where the tip of the infusion catheter is within the joint capsule.