Shoulder instability occurs whenever the humerus (the ball of the shoulder joint) pops out of the glenoid (the socket). There is a wide spectrum of this, from subluxation (the humerus slides off the g
Knee replacement surgery — also known as knee arthroplasty (ARTH-row-plas-tee) — can help relieve pain and restore function in severely diseased knee joints. During knee replacement, a s
