Trauma=meniscal tear. Usually trauma to the knee causes meniscal tears (cartilage tears) which can degenerate over time causing symptoms of pain, swelling, locking, and popping. An MRI is a good test to diagnose a meniscal tear and an orthopedic consult may be needed. Bone tumors of the femur or tibia are very rare.
Not typically. Meniscal tears are often caused by injury. The other cause that is fairly common is degenerative. Tumors within the bone do not typically cause meniscal tears. If you are referring to bone spurs as being a "bone tumor" than both bone spurs and meniscal tears can develop in the degenerative arthritic knee.