Dear Ask The Doctor: No one can seem to pin point what is wrong with my knee. I'm a 30 year old male with chronic knee pain for the past ten years. It originally started as a sudden sharp pain with squat jumps. The knee had swelling which went down after two weeks, but the pain symptoms have never left. My left knee presents with pain directly in front of the knee cap at around 30 degrees extension with force. The patella seemed to jump laterally with extension, but upon closer inspection I realize it tracks just fine. The sesamoid bone doesn't seem to shift laterally, however, it feels like a part of the tendon or tissue gets pulled over medial aspect of the sesamoid bone toward the center with extension. I can literally palpate something jumping laterally toward the center of the knee cap starting from the medial side, but it's not the actual knee cap itself. I'm not even sure if that is possible. It originally sounded like patellofemoral syndrome, but it doesn't quite fit. I'm still functional for daily living, but it's getting worse through the years. Have you ever heard or seen such a thing in a patient? Where could the pain be comming from?
Dear Kevin: Knee pain is the most common presentation of patellofemoral syndrome in young and active people. The pain typically is located behind or at the top of the kneecap and often shows during activities that require knee flexion and forceful contraction of the quadriceps (ei, during squats, ascending/descending stairs or pendants). Pain may be worsen by sitting with the knee flexed for a long period of time, such as while you are playing as a catcher, watching a movie, hence leading to the terms "theatre sign" and "movie-goer's knee." The causes are diverse: Overuse (repetitive use or activity), overloading, and misuse of the patellofemoral joint. The suggested strategy for conservative treatment should be as follows: Physical therapy program (exercises and pain control with TENS, ultrasound, ice packs after exercises), anti-inflammatory drugs (i.e.: “Aleve”, “Advil”), education to understands which activities avoid because those can aggravate patellofemoral syndrome. Also, and very important, remark the need for extended adherence to the exercise regimen. Your physical therapist should educate you about a home exercise program. Allow time for these conservative measures make any effect and improve your condition. On the other hand, given the description you have written about the problem of your knee, it might be important to rule out a Meniscus lesion. The menisci are C-shaped wedges of fibro cartilage located between the tibia and femur, and very close related to knee ligaments and attached also to the joint capsule. They are susceptible to get injured with leg rotation movements or rotational forces applied to them, and the lesion produced can be partial or complete tear. Meniscus injuries are common in active people as you, who are involved in sporting or physical activities. Pain along with locking or buckling is common symptoms after a meniscus lesion develops. Locking usually occurs at 20-45° of joint extension. If a torn fragment has been trapped within the joint, extension may feel limited against a rubbery resistance. Joint inflammation or capsular involvement also may resemble locking. A more reliable indicator of meniscus lesion is a click, pop or snaps after the joint unlocks, it can be or not associated with pain. A sensation of giving way may occur when the loose fragment becomes lodged for a moment in the knee joint, causing a sense of buckling. This finding should be distinguished from the sensation of giving way due to joint instability (eg, ACL tear) or buckling secondary to decreased activity of the quadriceps femoris muscle.