Colombia University scientists say they were able to regrow the thigh joint of rabbits from the animals' own stem cells using a process called tissue engineering.

The piriformis muscles, strong external rotators of the thigh, attach to the sacrum and the femur. Stretching them can increase S-I joint instability.

Pain in the side of your hip, usually at the joint of your hip and thigh but sometimes a bit higher toward the hip bone.