Hip Replacement Methods
Total hip replacement (THR) is a very successful medical treatment, with some of the greatest improvements in a person's quality of life measurements of any intervention in the whole of medicine. Hip replacement methods vary significantly but can be grouped into a few major approaches, all with their strong supporters and types of hip replacement.
The hip arthroplasty definition is an operative reconstruction of a joint whic is abnormal or its replacement with an artificial joint, usually of metal or metal and plastic components. Types hip replacement prosthesis vary greatly as many have been designed over time, but only a few have the long term published results to back up their use in large numbers of people
Total Hip Replacement using Cement
Since Sir John Charnley developed his hip in the UK in the 1960s cement has been used to fill the gap between the metal and plastic components and the bone. Initially there were significant problems with the implant loosening and needing to be redone, due to the connection between the cement and the bone either never developing or breaking down.
However, modern techniques including impaction grafting of the bone and pressurised cementing to push the cement into the bony structure have improved this markedly and the success of this one of the many types of total hip replacements has been remarkable. The vast majority of patients keep their replacement working well at the fifteen year mark and many for much longer.
This kind of hip replacement surgery is mostly used for elderly (over 65 years) people who have pain, limitation of movement and difficulties with daily living due the most common of the hip replacement causes, osteoarthritis of the hip. In many cases the hip will function well for the lifetime of the person.
Hip Replacement Surgery without Cement
Uncemented hip replacement has developed in parallel to cemented techniques but the long term results are not quite as good as the cemented versions. One of the problems with cement is that if the joint needs to be re-done then all the the cement has to be removed, a difficult and risky job for the bone of the upper thigh. Uncemented designs avoid this and are covered with a porous coating to encourage bone to grow up to and into the component surface, forming a firm lock.
Uncemented hip prosthesis types are said to be more suitable for younger people who will have to have the hip redone at some point which is much easier without having to deal with cement.
Resurfacing of the Hip
The Birmingham Hip Resurfacing system is quite different from the two types of hip replacement joints previously discussed, in that a much smaller amount of bone is removed before the components are fitted. The metal on metal components are two hemispheres and supporters maintain that bone is conserved for future possible operations, normal mechanical loads are placed through the femur which maintains bone, activity limitation is not necessary and that dislocation is rarer due to the large ball size.