A DOCTOR WRITES: Most of the thousands of people who underwent hip surgery in recent years have nothing to worry about
THE DISCOVERY of a problem with one of a number of hip replacement systems used to treat Irish patients will be a source of concern for anyone who has had a hip replacement carried out in the last five years.
However, the type of resurfacing operation involving the DePuy systems represents about 10 per cent of hip joint replacements carried out in the Republic.
Most of the thousands of people who underwent hip surgery in recent years, therefore, have nothing to worry about.
Two sub-types of hip replacement are involved in the current investigation.
One is the ASR articular surface replacement, which involves a recoating of the bone surfaces of the ball and the socket of a hip joint. The second is called the XL acetabular system; this involves resurfacing with the addition of a matched ball placed in the top of the thigh bone.
It has now emerged through unpublished research in the UK that both of these systems have required revision surgery at a higher rate than normal. All forms of hip replacement have a defined “life span”, but in this case the new hips themselves needed premature replacement in about one in eight cases.
The resurfacing procedure is different from the original type of hip replacement in which the ball and socket were replaced with metal components.
All patients who received these devices will be reviewed by orthopaedic surgeons in the coming weeks. Most will have noticed no problem since their operation; a minority may have experienced hip pain or difficulty walking.
The main reason why someone requires a hip replacement is because of severe “wear and tear” arthritis (osteoarthritis). Initial treatment of the condition includes physiotherapy and the use of anti- inflammatory drugs; when these no longer bring relief and where an X-ray confirms the surface of the opposing joints have been disrupted and the space between them narrowed, then referral to an orthopaedic surgeon with a view to having a joint replacement carried out.
Those called back for review can expect to undergo a clinical examination, blood tests and an MRI scan, which will allow an accurate assessment of how the replaced joint is functioning. A minority may require further surgery using a different type of joint replacement.
A modern hip or knee replacement typically lasts for 20 or more years. Over the last 30 years, improved surgical techniques and new implant materials have been developed, making total joint replacement a reliable and durable procedure.
About 80 per cent of people who have had a hip replacement will never require revision surgery.
However revision surgery is carried out routinely in patients who have had artificial joints that are past their “sell by date”.
In addition, a small number of patients require early revision for a variety of problems including infection or dislocation.