During a total hip replacement procedure a metal stem is inserted into your thighbone (femur). Attached to the neck of the stem is a hip ball, just over an inch in diameter. The hip ball fits into a liner. Together, the ball and liner create the new joint. The liner is inserted into a metal shell that in turn is anchored to your pelvis. In terms of fixation, your surgeon has the choice of anchoring the hip implants securely to bone using either cement fixation or fixation by 'bone ingrowth'. Your surgeon will select the design of the hip replacement and size of femoral ball to give you the range of motion and stability that you need to function.
Your body has to cope with any wear debris that is released when you use your hip implant, unlike your car engine that has special filters to remove the wear products. The standard metal ball and polyethylene cup have been in use for over 40 years. In younger, more active patients, there is a propensity for the metal ball to become scratched. Scientific studies indicate the use of improved polyethylene liners, called ‘highly crosslinked’ bearings, result in overall decreased wear of the implant.
If you are a very active individual or a relatively young patient, your surgeon may prescribe an all-ceramic hip joint. Such all-ceramic hip joints have been used .
In these hip joints the traditional metal ball and polyethylene liner are replaced by a high-strength ceramic bearing that has the reputation for ultra low wear performance. Clinical studies.