This abstract provides the general knowledge of the commonly described syndromes and diseases that can cause a fracture to a knee. Patellar Tendinitis, also know as Jumpers Knee, is the inflammation of the patellar tendon. This particular type of tendinitis is caused by running, jumping and kicking sports. The tendon becomes tender between the inferior pole of the patella and the tibial tubercle. The Sindig-Larsen-Johansen Disease affects the inferior pole of the patella where the patellar tendon inserts into the patella. This most commonly occurs in preteen males. The Osgood Schlatter Disease is a tearing or pulling away of the tibial tuberosity. There may be localized swelling and erythema over the tibial tubercle. There are 4 bursae around the knee. They are: prepatellar, suprapatellar, infrapatellar, and subcutaneous infrapatellar. The most common affected is the prepatellar. Most commonly the bursa will become swollen, extremely tender and warm to the touch. Hoffa's Disease also known as Fat-Pad Syndrome is closely associated with the infrapatellar bursa. It can become inflamed and the process appears to have 2 phases, acute and chronic. In acute there can be severe pain and a limitation of motion. If this occurs for longer than 3 months then it is considered chronic. Pain in this phase is localized approximately 1 cm below the inferior pole of the patella. A test that can be done, known as the Hoffa sign, begins with the athlete supine and with their knee and hip flexed at a 90 degree angle. The medial and lateral borders of the patellar tendon are then palpated, while pressure is put on the fat-pad. If the fat-pad is inflamed then there will be pain caused by the pressure. Plica are folds in the synovial membrane and are usually only present in the fetus. The most common reason is because of incomplete degeneration in the superolateral aspect of the knee. Plica's are usually tender when palpated. Softening of the articular cartilage is known a Chondromalacia, commonly is the grinding and clicking noises you hear in the athlete's knee. Tenderness is accentuated when the patella is pressed against the femoral sulcus and the athelete contracts the quadriceps. These are 7 of the most common diagnosis that athletes have or may encounter during their seasons. Having knowledge of at least these will give the athletic trainer or coach a way of evaluating and injury whether it is chronic or acute.