Having a stiff and painful hip can prevent you from doing even the simplest things in life. Activities, like walking or moving between the stove and the sink, can become so challenging your ability to look after yourself is compromised. If this occurs, slowly all the basic acts of self-care like shopping, eating, grooming, and even sleeping soundly, can become a burden. So all the things that once came so easily, become too painful for you function properly on a day-to-day basis.
Without the help of family, friends or some form of home-care help, people’s general experience of hip problems can be one of indignity and isolation. Even with help, there is always your loss of independence and the sometimes embarrassing loss of privacy. Both alternatives have serious downsides, so when your hip condition limits your movement to this extent, one humane option is to have total hip replacement surgery.
One of the great surgical advances over the last century is the total hip replacement. Total hip replacement revolutionised the treatment of hip ailments and is today one of the most successful, safe and reliable orthopaedic interventions in practice.
Prevalence and Benefits
In 2010 in the US, 332,000 total hip replacements were performed, while in Australia for the same year there were approximately 34,000. It is also estimated by the American Academy of Orthopaedic Surgeons, that 10 years after the surgery, 90-95% of people don’t need revision surgery. The success rate is similarly high in Australia. This means in both countries in 2010 at least one in a thousand people relied on a total hip replacement to remain active and self-sufficient.
When dealing with numbers like these, there are community benefits that go beyond the immediate personal benefits of the patient. By having the surgery, the patient’s sustained productivity and communal engagement have positive flow-on effects.
These effects increase the longer the patient's working life after surgery, so the younger the patient the more economic and social benefit. As the treatment gets more advanced, younger people are more regularly recommended and opting to have total hip replacements.
Since the introduction of total hip replacement surgery, the medical profession keeps on critically analysing operative practices to improve patient outcomes. This has meant procedures and the types of prosthesis materials used, have steadily become safer and more effective.
Total Hip Replacement Developments
The improvements made, since ivory was used in 1891 to replace the femoral heads of patients, have been numerous. Skin and other tissues, glass and then stainless steel, have all been used to replace degraded joint surfaces, in an attempt to make the movement of the hip joint smooth and pain-free.
In the 1960’s Sir John Charnley, designed what he called a 'low friction arthroplasty', which was in principle the same as the prostheses used today. His prosthesis came in three parts; a metal femoral stem, a polyethylene acetabular cup, fixed with acrylic bone cement. The feature of 'low friction', Charnley managed to achieve by the smaller surface area of his femoral head design.
Metal-on-polyethylene prostheses have become the most popular type and much of the hip replacement research carried out, has been done to improve on metal-on-polyethylene prostheses exclusively.
The most common problem to occur over the years with metal-on-polyethylene implants is the release of polyethylene particles into the surrounding tissue of the joint. Whereas, special treatment of the plastics used more recently, increases their wear resistance and limits the release of these harmful particles.
Metal-on-metal prostheses have regained favour since they were thought to potentially generate harmful metal ions. It is thought today that flaws in the early designs of metal-on-metal prostheses were the main reason for most of the difficulties associated with these implants, rather than the material they were made from.
Metal-on-metal prostheses are much more durable than polyethylene implants. Due to this feature the femoral head can be made larger which increases the weight bearing stability of the implant.
The use of ceramic-on-ceramic prostheses was adopted to reduce friction and wear. Ceramic-on-ceramic implants are hard and scratch resistant, and respond well to moisture. All these features limit the possibility and effects of friction. Loose ceramic particles are also inert and benign in comparison to polyethylene and metal debris when released into the body.
Because ceramic-on-ceramic prostheses are comparatively wear-resistant, they are more commonly used for younger and more active patients. They are, however, more expensive and require precise surgical insertion to avoid chipping and dislocation, both of which, can compromise the success of the implant.