Patellar tendinitis, also known as jumper's knee, is an overuse injury of the tendon that straightens the knee.[1] Symptoms include pain in the front of the knee.[1] Typically the pain and tenderness is at the lower part of the kneecap, though the upper part may also be affected.[2] Generally there is no pain when the person is at rest.[2] Complications may include patellar tendon rupture.[2]
Risk factors include being involved in athletics and being overweight.[1] It is particularly common in athletes who are involved in jumping sports such as basketball and volleyball.[1][2] Other risk factors include sex, age, occupation, and physical activity level.[3] It is increasingly more likely to be developed with increasing age.[3] The underlying mechanism involves small tears in the tendon connecting the kneecap with the shinbone.[2] Diagnosis is generally based on symptoms and examination.[2] Other conditions that can appear similar include infrapatellar bursitis, chondromalacia patella and patellofemoral syndrome.[1][2]
Treatment often involves resting the knee and physical therapy.[2] Evidence for treatments, including rest, however is poor.[4][5] Recovery can take months and persist over years.[6][7][8][2] It is relatively common with about 14% of athletes currently affected; however research reflects that more than half of athletes with this injury end their careers as a result.[9][8][1] Males are more commonly affected than females.[2] The term "jumper's knee" was coined in 1973.[2]
^Cummings K, Skinner L, Cushman DM: "Patellar tendinopathy in athletes". Curr Phys Med Rehabil Rep 2019;7:227–36
^ abPlinsinga M.L., Meeus M., Brink M., Heugen N., Van Wilgen P. "Evidence of Widespread Mechanical Hyperalgesia but Not Exercise-Induced Analgesia in Athletes with Mild Patellar Tendinopathy Compared with Pain-Free Matched Controls: A Blinded Exploratory Study". Am. J. Phys. Med. Rehabil. 2021;100(10):946-951. doi:10.1097/PHM.0000000000001673
^Kettunen JA, Kvist M, Alanen E, et al: Long-term prognosis for Jumper's knee in male athletes: a prospective follow-up study. Am J Sports Med 2002;30:689–92