Q&A with Sarah Muirhead-Allwood

I was told by my mother that I had the desire to be a surgeon from the age of 8, which is bizarre when you think about how young that was! My father was a doctor and I was always very practically minded, so perhaps it was a combination of the two which led me to medical school.

Whilst at medical school I was tempted to become a plastic surgeon and my first house job involved a combination of plastics work and orthopaedics, working alongside the now renowned hip surgeon Ronald Furlong, who performed hip replacements. It was here that I first really became interested in hip replacements, and I’ve never looked back!

By the time I started my registrar training as an orthopaedic surgeon, although the way hip replacements were performed had advanced a little, the failure rate was huge. Whilst in my training, I decided that I wanted to be a revision hip surgeon – putting right people’s failed hip operations. There were few people working in this field during my registrar training, which meant that I quickly became an established expert in that field and was recognised as such. 

After a while of being a revision hip surgeon, I decided that I also wanted to dedicate time into understanding why hip replacements were having such a high failure rate and how to improve the way hips were replaced.

Hip replacements are now expected to last up to 30 years, whereas when I first begun training as a surgeon, patients would be lucky if they lasted 10 years. The main reason for this change is that the material used for the bearing changed from metal on polyethylene, to ceramic on ceramic and also ceramic on highly crosslinked polyethylene, meaning that the bearing is less likely to wear out and the hip replacement is less likely to need revision. 

Another important change is that the incision size surgeons make is now much smaller. A ten-inch incision would have been the norm a couple of decades ago, whereas now the incision size I make is between 6-10cm on average. A smaller incision typically means that the patient will be recovered and back on their feet quicker.

The introduction of 3D printing technology in relation to hip replacement surgery is also really interesting. Traditionally the implants used in hip replacement surgery are produced in a range of standard sizes. As a surgeon, you choose the size which is the closest fit for your patient and then fit it into the most optimal position. With 3D printing technology, it means implants can be more personalised to the make-up of each individual patient.

I think the assumption is that hip replacements are only for the elderly, but because the way that hips are placed has improved in the last few decades, the age threshold of patients has shifted to a much lower age bracket, meaning it has become much more commonplace for those in their 40’s, 50’s and 60’s to undergo successful hip replacements, should they need to. The age range of patients I’ve operated on is huge – I've operated on 18-year-old patients and 101-year-old patients!

Many years ago, we would offer hip replacements to patients as young as 18 to treat rheumatoid arthritis which was then very difficult to treat with drugs. Now, we operate on the younger patient demographic primarily due to them being diagnosed with conditions such as slipped upper femoral epiphysis (SUFE). This is when the head of the femur (thigh bone) slips off in a backwards direction, for reasons that are not known. It usually happens around puberty and is more common in boys than girls.

As well as operating on patients from both ends of the age spectrum at my clinic at The London Hip Unit, the activity levels of those I operate on varies hugely. In the past I have treated elite sportsmen and women at the very peak of their careers – ensuring that they can return to the most elite level of sport after undergoing a hip replacement, something I might not have thought possible when I first started out as a surgeon.  

What I find most important as a surgeon is gauging from each patient what their expectations are post-surgery and ensuring that I am realistic with them about what they are likely to achieve.

I have absolutely loved being a hip surgeon and it has been incredibly rewarding, helping people getting back to doing what they love without any restrictions. The one thing I would say to new surgeons coming through and wishing to specialise in hip surgery is to try to be innovative. Although it’s harder to innovate now than it was when I first started out, there’s always room for change – areas such as 3D printing and artificial intelligence and augmented reality are areas which can definitely be explored. 

I would also say – never underestimate the value of your team. I have had the same surgical assistant by my side, performing operations with me, for over 27 years – very few people are able to match the way we work as a team to provide the very best care for our patients. We work like a well-oiled machine, and I genuinely believe that’s the key to our success.