Knee Replacement Surgeon in Dombivli Knee Replacement is made up of the lower end of the thigh bone (femur), which rotates on the upper end of the shin bone (tibia), and the knee cap (patella), which slides in a groove on the lower end of the femur. Large ligaments attach to the femur and tibia to provide stability. The long thigh muscles (quadriceps) give strength to the knee. The joint surfaces where these three bones touch each other are covered with articular cartilage, a smooth substance that cushions the bones and enables them to move easily. A thin, smooth tissue liner called the synovial membrane covers all remaining surfaces of the knee. This membrane releases a special fluid that lubricates the knee, reducing friction to nearly zero in a healthy knee. Normally, all of these components work in harmony. But disease or injury can disrupt this harmony, resulting in pain, muscle weakness and less function