Runner Knee

If you re a runner, you really don t want this to happen to you. The MRI of this left knee shows the presence of a ganglion cyst. 

Wiles and associates42 found that caffeine decreased the time needed to complete a 1500-m run and that it increased the velocity of the finishing burst among well-trained, middle distance runners. Jacobson and colleagues43 examined 20 elite, strength-trained athletes to determine the effects of caffeine on knee extensors and flexors. They found increases in voluntary strength and power output in this group of well-trained athletes. 

Plastic-metal combinations are now used in most knee prostheses. The knee prosthesis and numerous variations of this style utilize metal runners attached to the bottom of the femur that ride on HDPE tracks that are cemented on the tibia. The two parts of this prosthesis are each cemented into the bones with poly(methyl methacrylate) bone cement and are maintained in the proper relative positions to each other largely through the cartilage, tendons, and ligaments of the knee region. The spherocentric knee prosthesis is a more complicated device that involves a ball-in-socket arrangement similar to the Charney hip prosthesis. This device also utilizes a metal ball in a HDPE socket (1, 42). 

The Polycentric design was further modified by researchers at Mayo in 1973 to provide wider UHMWPE tracks (Bloom and Bryan 1977). Additional refinements of the Polycentric design, such as the introduction of UHMWPE runners with variable height, were proposed by Cracchiolo (1973). A review by Peterson and associates in 1975 provides an instructive summary of fhe differ-enf fypes of Polycenfric knee components, which were available from implant companies such as Howmedica and DePuy at the time. 

Next, every effort should be made to localize the pain as precisely as possible because this can provide useful information to target the US examination. As a general rule, diffuse knee pain derives from joint lesions, whereas more localized pain is more commonly related to tendon involvement and local disorders. Information on the character, duration and location of pain is extremely helpful in the evaluation of tendinitis. In jumper s knee , for instance, the patient typically reports pain over the most proximal portion of the patellar tendon, just behind the tip of the patella. Runners complaining of lateral knee pain and tenderness should be questioned for signs of tendinitis affecting the distal insertion of the biceps femoris and the iliotibial band, so-called runner s knee . In the event of soft-tissue lumps or indeterminate swelling around the... 

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