The artificial hip joint is a successful intervention for a variety of hip pathologies. The ability of the implant to be successful is due to in part to its unique properties and characteristics. Utilization of high grade metals, plastics, and polymers allow physicians to replace painful joints with highly functional, long lasting prosthesis. Although there are a variety of styles, all artificial hip joints have the same basic components.
Characteristics
According to the American Academy of Orthopaedic Surgeons, all materials used in constructing a total hip replacement have four characteristics in common. The artificial joint is biocompatible, resistant to corrosion, duplicate natural hip joints, and they meet the highest standards. These characteristics ensure that patients receive an artificial hip joint that is successful and meets their individual needs. In addition, these characteristics make for an artificial joint that lasts for many years.
Acetabular Cup
The acetabular cup is the part of the artificial hip joint that is inserted into the acetabulum, or socket, of the pelvis. Generally, this portion is made of metal, polyethelene, or a combination of polyethelene backed with metal, according to the American Academy of Orthopaedic Surgeons. These materials allow for movement of the artificial hip joint with a minimal amount of friction. In addition, these materials are long lasting, strong and hard to wear out.
Femoral Ball
The femoral ball replaces the original head of the bone with a high quality metal component. The femoral ball fits snugly inside the acetabular cup. This union provides for almost effortless rotation within the joint, according to HealthPages.org, resulting in movements of the leg in all directions. The femoral ball can be different sizes, depending on the size of the individual's original femur. The surgeon generally makes the decision about size during the actual surgery.
Femoral Stem
The femoral stem is connected to the femoral ball component of the prosthesis. The stem is surgically inserted into the shaft of the femur. Generally this component is made of a high quality metal. The femoral stem translates motion from the joint to the femur, allowing for movement of the entire leg. The femoral stem may be porous, a unique property that allows the bone to grow into the metal, holding it securely in place, the American Academy of Orthopaedic Surgeons notes.
Cement
Some surgeons prefer to use cement to hold the femoral stem into the shaft of the femur, but it is not always used. The property of cement helps to ensure a strong bond between the femur bone and the femoral stem component. Both cemented and cementless artificial hip joints share the same basic properties, however cemented hips may be able to bear weight sooner than cementless replacements. A cemented femoral stem component tends to be shorter than cementless stems.
