- Popping sensation
- Swelling and stiffness
- Abnormal mobility of that knee
- Locking or catching of the knee at a 45-degree angle
CausesTorn meniscus is the major cause
The complex interplay between instability, torn menisci, athletic activities, muscle control, and cumulative joint trauma ultimately leads to a degenerative change in the knee. It is often unclear what mechanism caused the disability, e.g. the original injury, repeated locking, instability, high athletic demands, powerful muscular contractions, repeated trauma or altered mechanics.