A Brief History Of Hip Replacement Surgery part two
In the last decade, several evolutionary improvements have been made in the total hip replacement procedure and prosthesis. Many hip implants are made of a ceramic material rather than polyethylene, which some research indicates dramatically reduces joint wear. Metal-on-metal implants are also gaining popularity. Some implants are joined without cement; the prosthesis is given a porous texture into which bone grows. This has been shown to reduce the need for revision of the acetabular component. Surgeons still frequently use bone cement for the femoral component, however, which has proven very successful after 35 years of clinical experience.
The latest developments are several competing Minimally Invasive Surgery (MIS) approaches, which may result in far less soft tissue damage and a quicker recovery. C.A.O.S (Computer assisted orthopedic surgery) is also being marketed heavily by the implant manufacturers, though its value remains largely unproven.. Computer assisted surgery is said to better navigate prosthetic implantation.
An alternative to total hip replacement (THR) is hip surface replacement (HSR), also referred to as hip resurfacing. With both THR and HSR, a prosthetic socket is pressed into the pelvis. With THR, the end of the femur is amputated, a metal shank is inserted into the femur, and the shank holds a ball which mates with the socket. With resurfacing, the end of the femur is not amputated; the outer surface of the femoral ball is replaced with a cylindrical metal cap. Resurfacing eliminates the common THR problem of the metal shaft loosening from the femur. Resurfacing preserves bone stock if a revision is ever needed. A larger diameter ball and socket more closely mimic the natural joint structure, reducing the risk of dislocation and improving range of motion. There has been no published clinical evidence to show that today’s CoCr metal-on-metal articulating surfaces have the osteolytic effect on bone that earlier polyethylene devices had. Ten year success rates of hip resurfacing from studies in England report success equal to or greater than standard total hip replacement, in age-matched patients. In the United States, the first modern resurfacing device received FDA approval in May 2006, while some 90,000 resurfacings have been performed world-wide.
Patients need to be aware of all surgical options before hip replacement surgery. Hip surgeons have different surgical techniques and surgical outcomes. Currently, there are several different incisions used to access your hip joint. The posterior approach (widely used by the majority of orthopedic surgeons) separates the gluteus maximus muscle in line with the muscle fibers to access the hip joint. Other methods access the hip from the lateral side of the hip joint. In contrast to the posterior approach and lateral approach, the anterior approach uses a natural interval between soft tissue to gain access to the hip joint. Its main disadvantages are that it risks damage to the lateral femoral cutaneous nerve, and it is not widely available to the public because fewer surgeons have been trained in this technique.