A hip replacement is usually performed when the hip is damaged from wear and tear (osteoarthritis), inflammation or trauma. It involves an operation to remove the damaged joint and replace it with an artificial one. An incision (surgical cut) is made in the skin. The hip is surrounded by muscle, which either needs to be cut or moved aside.
How do you perform your hip replacements?
'Once I have gone through alternatives to surgery, and made sure that the patient is sure that they want surgery, I will discuss the implant type with the patient. Often, this is an easy choice, but sometimes this decision can take time.
I operate in the NHS at the Sussex Orthopaedic Treatment Centre in Haywards Heath, and both for the NHS and privately at the Montefiore Hospital in Hove.
I use a digital templating system to help plan the surgery. Patients are usually admitted to the hospital an hour or two before the operation. The anaesthetist usually uses a spinal anaesthetic, and then can give sedation to the patient if they wish. A few patients want to be completely awake so they can watch the procedure, but most want to be asleep so they are completely unaware of the procedure.
I use a minimally invasive / muscle sparing approach where possible. It is not always appropriate to do minimally invasive surgery on every patient. The aim of the surgery is to have a safe hip and to minimise the risk of complications. My preferred technique is a muscle sparing posterior approach. Using specialized retractors, the hip can usually be exposed with only cutting one tendon, which is then repaired at the end of the procedure. This allows a faster recovery, with less risk of the hip dislocating as there are fewer muscles to heal. I also perform a full capsular repair when possible to reduce the risk of the hip dislocating further. '
What does minimally invasive mean?
A few surgeons offer smaller incision surgery. They perform a standard hip replacement through a smaller incision. Whilst this has some advantages to the patient in terms of scar length, the surgeon still cuts the standard amount of muscles inside. Most surgeons repair the muscles that they cut.
Minimally invasive can also mean muscle sparing. With a muscle sparing approach, fewer muscles are cut, and more of the natural hip structures are retained. This makes the hip more stable, stronger and quicker to get going. This can be seen right from the first few days after the hip replacement. Patients can often get back to their daily routine more quickly. If the patient is comfortable - driving is sometimes possible from 2 weeks post-operatively.
Mr Stott's minimally invasive / muscle sparing technique
Obturator Internus in red
Obturator internus has been carefully cut off the femur, and folded backwards, revealing the hip capsule, and oburator externus just above quadratus
Under the gluteus maximus muscle, there are 4 muscles at the back of the hip - the Short External rotators;
- Obturator Internus (with its 2 Gemelli)
- Obturator Externus
- Quadratus Femoris
On the image, the Obturator Internus is highlighted in green, and obturator externus is just seen behind the quadratus femoris.
Most surgeons doing the posterior approach will cut all 4 muscles, and then most of them will repair them. Mr Stott has developed a technique, where only the Obturator internus is cut. This is then repaired at the end of the procedure.
This means that less damage occurs during the surgery, allowing quicker recovery and a more stable hip replacement
There are over 100 different hips on the market in the UK, so how do I know which one is right for me?
‘Everybody is different. You notice that peoples’ faces are different, and that people come in all shapes and sizes. People have different needs and expectations from their hips. Some people are young and high demand, and need a hip that can perform well enough to allow sport. Some people need a hip that can be put through an extreme range of motion without dislocating, such as climbing or yoga. Some people have lost mobility and want to gain their independence again. Most people with hip problems want to get out of pain and regain their life in the quickest and safest possible way.
Many surgeons will use just one operation or implant for all cases. They will argue that this implant comes in different sizes. However, some implants are better for different shapes of bone as well as different sizes. Some implants are stronger than others, but come with their own problems and nuances. If there was a perfect hip replacement, every surgeon would be using it for every patient.
'I do not believe in a ‘One size fits all approach'. There are no cookbooks of hip surgery, where just because you have a problem means that there is only one treatment’.
Do you use the latest, most modern hip replacements?
Scientific knowledge continues to move progress. However sometimes theories have been proven wrong, and caused patients harm. Two memorable recent ones have been the Capital 3M hip, and the ASR. Both of these had excellent scientific theories behind them, but in practice had unacceptable failure rates that caused many patients harm. Fortunately, we have registries, which monitor how the replacements perform.
I would recommend that the femoral part of hip replacements which are used, have at least 10 years of use in real patients and in real conditions. The majority of hip replacements that I use have over 25 years of data, and are some of the best performing on our national joint registry (Exeter from Stryker and Furlong HAC from JRI).
We know that these tried and tested hip replacements have excellent results in many thousands to millions of patients. For patients who want to continue playing sport, there are different options depending on which sport and what level. I use a short stemmed hip (B Braun Metha) for patients that are involved in impact sports and where the shape of the femur will allow. This operation is slightly more bone conserving – both in how much bone is cut away and how much of the femur is used to get purchase on the stem. This will also keep bone stock for the future. Patients report that it feels more natural. This hip is used more commonly in Europe, and was first used in 2005. The results to 17 years seem very good. This hip does not have the long track record of other hips that Mr Stott commonly uses.
The X-ray of this patient shows a short stem Metha Hip replacement. This patient is a keen runner, and was able to get back to running long distances after their rehabilitation
What about custom made hip replacements? Surely they are made to fit me, and will have the best function?
'I do use custom hip replacements for complex cases where there is little other choice. Usually this is because the patient has had previous surgery, and there are anatomical deformities which would preclude the use of a tried and tested hip replacement. I am currently using the Symbios system from Switzerland. Whilst these hips are custom made to fit, each design is different, and therefore has not had the same exposure as the 25 year old plus designs that I commonly use.'
John was in his early 40s. He had suffered from a disease called Perthes when he was a child, and had a series of operations on his hip. He has been struggling on for many years with a short, stiff and painful leg.
The X-ray shows how abnormal his femur was, with the femoral head collapse, and where surgeons had operated on him to change the angle of his hip.
He needed his hip replacing. Traditionally, John would have had to undergo one operation to restore the shape of his femur. This would have involved putting some metalwork in to support the bone as it healed. He would then need a second one to remove this metalwork, and a third one to do the hip replacment.
Custom Hip Case example
With one operation, John's life was transformed. Using a Custom made hip replacement, Mr Stott was able to restore John's leg length and function. He was ready for discharge the following day post-operatively.
He reported that his mother cried when she saw him at two weeks, already walking better than he had since he was a child.
Pre-op X-ray of John's hips
Post-op X-ray of John's new Custom made hip