Painful "lump" under left knee


Q: Under my left knee i have a "lump". it's not really a lump of any sort my bones just juts out under my left knee, but not on my right. it sometimes cause me pain if i keep that knee bent for long peroids of time or if i bump it on anything. i have tried using a knee brace and over-the-counter pain medications but nothing has worked. my boyfriend thinks i may have at one point dislocated my knee and it never set correctly. does that sound like anything you know of or something that can me fixed?


A:   Based on your description most likely you may have a liquid collection in your prepatellar bursa produced by the previous traumatism that maybe you do not recall. The prepatellar bursa is a superficial bursa with a thin synovial lining located between the skin and the patella. Normally, it does not communicate with the joint space and contains a minimal amount of fluid; however, inflammation of the prepatellar bursa results in marked increase of fluid within its space, like a “golf ball”. Apparently you had an uncomplicated knee injury that with conservative treatment has a great chance to improve, anyways if you notice one or more of the following symptoms: more inflammation, remarkable limitation on flexion-extension movements, locking of the knee, or instability, the next step would be an evaluation by an Orthopedic Surgeon. But if this is not the case, the suggested strategy would be: protection (avoid activities or movements that may produce pain, especially kneeling), local ice packs for periods no more than 15 minutes each time, and after, local hot compresses, you could use anti-inflammatory medication (i.e.: “Aleve”, “Advil”).

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