The knee contains various types of cartilage. Hyaline cartilage lines the ends of the bones, providing a smooth surface. The meniscus, a fibrocartilage, differs in properties and composition.
To avoid confusion, I refer to the bone lining as "cartilage" and the meniscus as the "shock absorber."
The meniscus is commonly torn during a twisting knee injury, when it gets trapped forcefully between the thigh (femur) and leg (tibia) bones. This can happen alongside other knee injuries, like anterior cruciate ligament rupture. Often, patients cannot recall the exact incident that caused the meniscus tear.
The swelling, when present, usually fluctuates with activity and settles with rest and medication
Meniscus tears commonly cause sharp, sudden stabbing pain, especially during deep bending or twisting movements
The loose piece of meniscal tissue gets intermittently caught between the two bones of the knee
The meniscus acts as a knee "shock absorber" between the thigh (femur) and leg (tibia) bones. It reduces load transmission, provides stability, and helps disperse fluid around the knee joint.
Most meniscal tears initially receive non-surgical treatment for 3-4 weeks.
If symptoms are improving, there is no rush for surgery. However, if symptoms persist beyond 6-8 weeks without improvement, surgery may be considered.
Initial treatment for meniscal tears typically involves RICE (rest, ice, compression, elevation) and the use of over-the-counter pain relievers like non-steroidal anti-inflammatory drugs (NSAIDs).
In rare cases, a locked knee may occur when a meniscus tear causes limited or no movement. Semi-urgent surgery is advised to unlock the knee and prevent further damage.
Similarly uncommon, a large meniscal tear called a bucket handle tear may not affect motion but can damage the knee's normal cartilage if left untreated.
In the majority of cases the meniscus tear is unable to be repaired and is removed
Meniscus tear (up) and post meniscectomy (down)
The meniscus is surgically removed using keyhole arthroscopy.
Two small incisions are made in the knee: one for a camera and the other for instruments like scissors and shavers. Fluid is used to inflate the knee for better visualization during the procedure.
Meniscus repair is done through keyhole arthroscopy, typically with two stab incisions in the knee.
The tear is assessed for repairability, and sutures or suture darts are used for the repair. Additional incisions may be necessary for completing the repair process.
Loss of a portion of the meniscus can lead to increased stress on the articular cartilage that lines the knee.
We know that if the entire meniscus (100%) is removed, that side of the knee, which now has no meniscus, will develop arthritis in 20-30 years time. Thankfully, in the vast majority of cases much less than 100% of the meniscus is usually removed (most commonly 30%). The general principle is to remove as little of the meniscus as possible to improve the patient’s symptoms.
If the adjacent cartilage is already worn (pre existing osteoarthritis), then the likelihood of progression of the arthritis is higher.
Certain meniscal tears can heal, especially smaller tears located in the periphery of the meniscus where there is better blood supply. The healing potential is further increased if the tear is accompanied by an ACL rupture. However, the ability of the meniscus to heal diminishes with age.
The incidence of a meniscal tear with no symptoms, diagnosed incidentally on a MRI scan is approximately 5%.
This percentage increases with increasing age.
For example, if you have pain on the inner side of your knee (medial side) and the MRI shows a tear in the meniscus on the outer side (lateral) then it is likely that your meniscal tear is asymptomatic and the cause of your pain is something other than the meniscal tear.
Dr Seeto in affiliation with Medibank Private and East Sydney Private hospital, offers a program for eligible Medibank Private Members, to eliminate medical out of pocket costs for your Knee Replacement.
The program includes a pre-surgery preparation program, spending the minimal time necessary in hospital, as well as home rehabilitation if necessary.