For a three variable system of equations to be consistent, the equations formed by the equations must meet two conditions: 1  All three planes have to parallel. 2  Any two of the planes have to be parallel and the third must meet one of the planes at some point and the other at another point.
Osteoarthritis affects 20 million Americans, occurring most often in women and adults older than 45. Osteoarthritis can affect any joint, but it most often occurs in the knees, hips, spine and fingers. At first it may affect only one joint, but if the joint is in the fingers, multiple hand joints may become affected.
Osteoarthritis can cause severe joint pain, swelling, and stiffness. In some cases it also causes reduced function and disability; some people are no longer able to do daily tasks and, in some cases, are not able to work. Severe cases may require joint replacement surgery, particularly for knee or hip OA. Top of Page.