What are the knee diseases? The following diseases are common: 1, knee fracture, sprain, joint instability, meniscal injury; 2, osteoarthritis, synovitis, rheumatoid arthritis, rheumatoid arthritis; 3, osteophytes, osteoporosis; 4, bone tumors, bone tuberculosis; 5, fossa cyst, gout, acute and chronic inflammation; 6, congenital and acquired deformities of various unexplained causes of knee pain and movement dysfunction and other diseases. In short, any knee discomfort or difficulty in movement belongs to the category of knee arthropathy, and can be seen or consulted at a knee arthropathy specialist.