When I had my first meniscus injury it was late in a 2 hour tennis match, I was tired. I back pedaled to cover a lob and jumped up. When I came down I could feel the slight injury. For 2 months a slight pain at that location in my knee did not go away and occasionally my knee would be shaky in some turning positions. 2-3 months later it got much worse with a sudden bone-on-bone sensation, severe pain, scream, fall, etc..
I have viewed that first meniscus injury as an acute injury and no time allowed for healing (or, if not healing, is there cartilage remodeling?). I do not understand what caused the feelings, so speculating -other mini injuries followed the first until the bone-on-bone sudden severe pain which was probably the tibular and fibular articular cartilages contacting each other or muscle spasms pulling my knee joint out of kilter. ?
I view what happened in my meniscus injury as a series of acute injuries over about 2-4 months without any time off to heal. That seems different from the undefined medical term 'wear and tear'. Is wear & tear just failure to allow healing time for very small asymptomatic injuries?
I suppose similar acute injuries could occur directly to the articular cartilages. Under what circumstances does the meniscus protect the articular cartilages?
ADDED 12/11/2012 - Acute articular injuries & overview