I went to the doc finally last week, and he immediately identified my problem as being an inflamed or torn meniscus, in addition to the medial collateral ligament tear that I was already aware of. Monday I'm going in for an MRI to see exactly what type of tear I have. Below I've posted some info about meniscus injuries in general fromthe website kneeguru.co.uk. I'll write more when I know what the MRI shows.
The menisci are horizontal wedges. a single meniscus appears - a bit like a squashed orange segment lying on its side, and wedged between the long bones of the knee.
Made of a smooth white glistening fibrous material, they absorb impact and act as shock absorbers. They are really important. Each knee has two menisci, one to support each of the rounded ends of the femur (thigh bone). They are wedge-shaped and curved, with the wider part of the wedge forming the outer rim and the inner rim being the sharp surface.
Menisci can be the main focus of damage during a knee injury ('primary') or it can be a consequence of another problem inside the knee ('secondary'). A tear can also be part of a compound injury when other structures are damaged at the same time. (In my case a torn Medial Collateral Ligament).
In a tear of the meniscus, there is usually a twisting force with significant torque. A skier with tight bindings may have the full rotatory torque of the ski applied to this small structure.
Injuries of the meniscus occuring in association with other injuries may have a different mechanism. Anything which allows the femur (thighbone) to slip abnormally forward or backward in relation to the shinbone (tibia) may cause some of the forces to be transmitted to the meniscus and result in a meniscus tear. Such injuries may be cruciate tears, cruciate and collateral tears, dislocation of the knee etcetera.
MRI is one of the most frequent investigations these days for meniscal tears, as a good radiologist will be able to identify the type of tear and its extent. X-ray is largely unhelpful. (I’d like to say thank you to my doctors who treated my knee for not taking an MRI, and for assuring me that the injury was limited to my ligament).
Blood supply issues
The extent and position of the meniscus damage matters:
•the inner sharp edge of the meniscus does not have a blood supply and tears here do not heal - this is referred to as 'white-on-white'. (This may explain the month of knee pain I’ve had without improvement)
•between the inner edge and the outer edge there may be sufficient blood supply to heal the wound - tears here are referred to as 'white-on'red'
•along the outer rim the blood supply is good and most tears will heal - tears here are referred to as 'red-on-red'
The type of meniscal tear is of relevance, as some tears can be treated surgically and some can not. The meniscal damage may simply be a frayed edge - seen as ragged fronds on the sharp edge of the meniscus. A frayed inner meniscal rim is usually of little consequence and seen frequently. Surgeons usually trim away the area to tidy it up and prevent enzyme release from the area. All the surgeon can do here is to trim away the edge and hope that the fraying is contained.
Far more probematic is the degenerate meniscus, when the whole meniscus undergoes internal change, and simply collapses in a ragged fashion. The shock-absorber function is grossly impaired and the cartilage at the ends of the long bones of femur and tibia become stressed and arthritis can ensue.
