The ASR Acetabular System falls far short of other total hip replacement systems. Here's how.

In a previous article we wrote on bone deterioration, we discussed how the bones of your hip are constructed and how a hip implant strives to mimic the qualities so that you can maintain a normal range of movement and a fairly active life.

In this article, we'd like to show you how the ASR XL Acetabular System was constructed - and why it fell so short of what hip implant patients needed to give them back their previous quality of life.

What a Hip Implant is Up Against

Any hip implant is going head-to-head against the natural construction of your body, which is no easy feat. What we think of as our hip is actually two bones: the acetabulum (also called the hip socket) and the femoral head, which is the rounded top of your femur (the main bone that runs the length of your thigh).

hip1

As you can see, the two bones of your hip are actually attached to each other securely by two ligaments. The shorter ligament at the center of the femur head is the transverse acetabular ligament, while the longer ligament that runs from the ilium down to the femur itself is the iliofemoral ligament.

These ligaments, along with the cartilage surrounding the hip joint, are the reason your hip doesn't dislocate on a regular basis. The iliofemoral ligament in particular is extraordinarily strong - in fact, the strongest ligament in the human body - and when you are standing or sitting, this ligament flexes or releases to allow a range of movement without letting the hip move out of the socket.

For its part, the transverse acetabular ligament and the surrounding cartilage make up the acetabular labrum, whose purpose is to deepen the hip socket so that the head of the femur can't slip out. The deeper the hip socket, the more secure the femur bone becomes and the less likely your hip will dislocate.

When your natural hip is removed to make way for a hip implant, neither of those ligaments is in place, and the cushion of cartilage is removed to make way for an artificial replacement. Removing the labrum means that your hip is 92% more likely to suffer contact stresses and 40% more likely to allow the femur and acetabulum to touch.

As you can see, your hip is a sophisticated and well-constructed mechanism, and it is extremely difficult to create a man-made replacement for it. Let's take a look at some of the best attempts available in the form of conventional hip replacement and total hip replacement systems, including the ASR Acetabular System. Read more ....