Volume 194 - Issue 12
The ASR Hip Resurfacing System: my experience
Author: Catherine S Gunson
Med J Aust 2011; 194 (12): 661-662. || doi: 10.5694/j.1326-5377.2011.tb03157.x
Published online: 20 June 2011
Published online: 20 June 2011
I was first diagnosed with osteoarthritis in 1989, at the age of 19 years. I had been having problems with horse-riding (my all-consuming hobby was equestrian competition — eventing and showjumping), getting pain in both hips when riding larger horses and after long rides. In hindsight, I had been showing symptoms for years. From a young age I had trouble sitting cross-legged, and at age 16 had started getting some lower back pain, which I now believe was a consequence of developing flexion deformities. I was told that I would need hip replacements by the age of 40, but that I must try to postpone this evil day as long as possible because hip implants only lasted about 10 years. As my inflammatory markers were never raised, treatment was conservative (non-steroidal anti-inflammatory drugs, paracetamol, physiotherapy and exercise), and I was encouraged to continue my equestrian activities as a form of physical therapy.
In 1996, I moved to Adelaide to commence a graduate medical course (my first degree was in molecular biology and immunology). My arthritis symptoms gradually interfered more and more in my daily life. By the time I graduated, I was experiencing continuous pain on weight-bearing on the right side, and by the end of 2003 I was unable to ride my beloved horses at all.
In 2007, my symptoms accelerated until I was unable to stand on my right leg and had to walk with a stick. It was clear that it was time for more drastic intervention and, as predicted, I was approaching 40. In November, I selected an orthopaedic surgeon, based partly on the experience of a colleague’s husband, a marathon runner of similar age to me, who had recently undergone a new hip resurfacing procedure that had been developed for younger, more active patients. The surgeon told me that the new metal-on-metal hip resurfacing implant would give me back a normal range of movement and mobility and that it would last 30 years. He also said that he had helped design software that enabled computer-guided placement of the implant to within 1 degree of the patient’s original joint position. He organised for me to have bilateral corticosteroid injections in my hips, to help with pain management and so that I could exercise and develop some muscle strength before surgery. My husband (also a doctor) and I did a basic literature search and found some questions about metal ion deposition and systemic release. On raising these concerns with the surgeon, I was told that this was not a problem with these implants. The brand of device to be used was not discussed before my surgery; it was only later I learned that the devices implanted were both the ASR (articular surface replacement) Hip Resurfacing System (DePuy Orthopaedics, Warsaw, Ind, USA).
I had the surgery in April 2008 — the right hip first, followed by a hospital stay of 5 days, then 2 nights at home before the left hip was replaced. I had a fairly prolonged recovery (I was only able to return to work, part-time, in late November) and thought this was due to having both hips replaced within a short time and also to the severity of my arthritis. The surgeon told me that, at operation, both hips looked to be the end result of untreated congenital hip dysplasia, which is a common cause of premature osteoarthritis. I attended physiotherapy every 2 weeks, working hard to stretch out my flexion contractures, and saw the surgeon for follow-up in May, July and October; examinations and x-rays all apparently looked as they should. I gradually improved and was pleased to have a return of a greater range of movement, although a minor fall in December 2008 led to acute right hip pain, which resolved after following advice from my surgeon to avoid weight-bearing for 6 weeks.
I continued to improve throughout 2009, although the right hip was never fully pain-free on weight-bearing. In late 2009, I developed pain in my right hip that was worse when lying on my right side, and in February 2010 my rheumatologist diagnosed right trochanteric bursitis (confirmed by ultrasound). I contacted my surgeon, who advised against a cortisone injection. Instead I was given some exercises (“sit like a man”, “walk like Charlie Chaplin”) and instructions to “avoid stairs” and ice the affected bursa.
The bursitis pain continued, and I began to develop groin pain in both hips, mainly on weight-bearing. The pain became worse and was affecting both my work and my home life. In the middle of 2010, I received a letter stating that my surgeon had retired, and that an appointment had been made for me in October with his replacement. Unsure what to do (and unsure if anything could be done anyway), I waited.
It was almost a relief when I first heard the news in August 2010, via the New York Times website, about the ASR hip systems being recalled — perhaps this explained my symptoms. In October I saw the replacement surgeon, who noted a globally decreased range of movement in both hips, restricted by both stiffness and pain. My serum metal ion levels were not elevated (chromium, 38 nmol/L; cobalt, 19 nmol/L). Magnetic resonance imaging and ultrasound confirmed the right trochanteric bursitis and I had a cortisone injection, which relieved the bursitis pain but not any of my other pain. I was told that, at this point, revision surgery was not yet necessary. I have since sought a second opinion with an independent surgeon, and investigations are continuing. My pain has worsened on both sides, and my flexion contractures have returned, as well as further global restriction of my range of movement.
After first hearing of the ASR implant recall, I had done some research and found that concerns had already been raised on the Australian Orthopaedic Association National Joint Replacement Registry (whose annual reports are freely available on the internet) about a higher than expected early failure rate — in 2006 for the ASR resurfacing system, and in 2008 for the conventional ASR. Through the media (the ABC television program Four corners in May 2011), I discovered that many other patients with the ASR hip replacement had had significant problems after their surgery.
If I had not been a doctor, I wonder whether I might have gone into this with more scepticism. “Regular” patients frequently attend their consultations armed with notes from “Dr Google”, family or friends’ anecdotes, and warnings from their naturopaths. They do some kind of research, however ill guided it might be. As a doctor, however, I have always trusted my colleagues. How can I refer my own patients to a fellow doctor if I don’t trust him or her to do the right thing? I think I trust(ed) my colleagues much more than a non-doctor would. We have the shared experiences of medical school, internship and resident years, and I have seen the rigour expected in specialist training. I have always put my faith in specialists to do the right thing. The only exception has been when I have heard about doctors who prescribe a remedy (frequently a “non-allopathic” formulation), then sell the patient a bottle of it from their medicine cabinet. I have always believed that you shouldn’t prescribe what you also sell.
Had I known more about this device, its development and its potential problems that were already known before I had my surgery, I would have asked many directed questions, done more research and perhaps sought another opinion. After all, nobody unknowingly volunteers to be part of a Phase IV clinical trial, do they?
Competing interests
I am participating in the Shine Lawyers class action lawsuit against DePuy.
Provenance: Commissioned; externally peer reviewed.