Hip & Knee Experts

Specialising in complex revision surgery

Mr Simon Bridle

Mr Bridle specialises in hip and knee replacement surgery. As well as performing a large number of primary replacements, including complex cases, he has an interest in revision surgery following implant failure and in particular the treatment of infected hip and knee replacements.

Mr Bridle was appointed as a Consultant Orthopaedic Surgeon at St George’s Hospital in 1994 and continued this role until August 2016. As well as a busy clinical practice, helping run the Complex Arthroplasty Unit, he has been active in management, including roles as Lead for Orthopaedics and Clinical Director for Surgery and Clinical Director for Major Trauma

Mr Bridle runs a medico-legal practice, advising the lawyers on claims by patients with complications following hip replacement.

Mr Bridle has participated in research projects and contributed to a number of publications during his career and is heavily involved with training junior doctors and helped supervise a Senior Fellow at St George’s. He lectures on revision hip surgery on a regular basis and runs the Orthopaedic section of the annual Doctors Updates meeting.

For more information on Mr Simon Bridle, please visit his personal website.

Mr Philip Mitchell

Born in Lincoln, Mr Mitchell qualified in 1991 from St Mary’s Hospital, London. He was a constant member of the London Hospital’s Cup dominant rugby side of the 1980’s and also obtained a first class honours degree in neuroscience.

Mr Mitchell trained in Orthopaedics at St George’s Hospital, London and spent a year in Vancouver from 2001-2002 on Fellowship. The Adult Reconstruction Fellowship in Vancouver is the premier joint reconstruction fellowship in the world and whilst there he published many scientific papers and completed his training in hip and knee surgery.

Mr Mitchell took up Consultancy at St George’s Hospital, London in 2002 and has been in post there ever since. His interests are hip and knee replacement, revision hip and knee replacement and particularly the treatment of infected joint and joint failure with significant bone loss.

Mr Mitchell is a keen teacher, having been on the faculty of major international courses from the outset of his consultant career.

Mr Mitchell has just completed 3 years on the Council of the British Orthopaedic Association, has been a member of the ODEP and Beyond Compliance panels and a board member of ARMA. He is now the Medical Director of the South West London Elective Orthopaedic Centre (SWLEOC), the busiest joint replacement centre in the United Kingdom.

Fortius Joint Replacement Centre

Mr Simon Bridle and Mr Philip Mitchell are part of the Fortius Clinic, a leading UK Orthopaedic Clinic, with locations in central London and the City. They are also both part of the Fortius Joint Replacement Centre, newly opened at Bupa Cromwell Hospital. The centre is a partnership between Bupa, a leading global healthcare company, and the Fortius Group of orthopaedic specialists.

An expert team of surgeons and anaesthetists has worked together to review the latest evidence supporting patient care pathways and to share their thinking on best practice. From this, they have developed a unified approach that aims to help patients to recover as fast as possible after their surgery. This means that, as a patient, you benefit from a shorter stay in hospital and a carefully-managed return home.


Failed Hip & Knee Replacement

A hip or knee replacement is a life-changing procedure that can improve quality of life immeasurably, hopefully returning you to near normal function. There can be many reasons, however, why a hip and knee replacement may require further surgical interventions in the future.

Wear and loosening of the artificial joint leading to bone loss, instability, infection, and fractures of the bone around the implants can all lead to failure, pain and loss of function and the need for further surgery.

Revision surgery is often a challenging procedure and it is important that it is performed by experienced surgeons, supported by a team who understand the demands and complexity of these cases.


Loosening of the artificial prosthesis can occur early on, if the components do not bond to the bone, but is usually a very late complication, occurring many years after the primary procedure. An artificial joint must become integrated with the bone to provide stability and function, but over time the implant can loosen, typically due to wear and bone loss. The artificial parts start to move against the bone, damaging it and causing increasing pain and loss of function. A new joint needs to be implanted, replacing and reconstructing the damaged bone, to deal with this.


Dislocation of a joint replacement can occur in the immediate aftermath of surgery if the leg is placed into an extreme position before the tissues have healed and sometimes if the components have not been put in the ideal position and this may require further surgery. Instability in either the hip or knee can also occur at a later stage as a result of wear of the components, soft tissue deterioration or trauma. In this situation, the joint is likely to remain unstable and the only way to deal with this is by revising the joint, often using special components to ensure that we obtain a stable joint.

Length Inequality

Difference in leg length and in particular lengthening, can be very troublesome after a hip replacement procedure. When there is a significant discrepancy between leg lengths, patients will often find this very disabling, experiencing pain, muscle fatigue, numbness and general dissatisfaction, requiring revision surgery. This is a highly specialist area as often it is necessary to remove well-fixed components from the bone and it can require the use of special components to avoid instability, as the soft tissues will have been stretched if the leg is too long.

Infection After Hip & Knee Replacement

Infection is a potential complication after any surgical operation and after a knee or hip replacement procedure it can occur in the immediate period after surgery or may develop many years later. Infection will cause pain and eventually loosening of the joint. If an artificial joint has become infected, then the type of bacteria, length and degree of infection will all be taken into account when planning treatment.  Surgery will almost always be necessary, as antibiotics alone cannot fight the infection.

Sometimes infection can be dealt with one operation, or a two-stage procedure may be required, with the implant completely removed to treat the infection with antibiotics before a secondary procedure is performed to insert a new prosthesis.  This is a highly complex area, requiring a surgical team experienced in treating infected joints.

Painful Hip & Knee Replacement

Pain is usually the primary reason why you might embark on a hip or knee replacement in the first place, so it can be very frustrating to start experiencing a high degree of discomfort, sometimes many years after successful joint replacement surgery.

There are many reasons why joint replacements become painful, including loosening, infection and instability. The cause is not always easy to identify and extensive investigations can be needed to identify the cause.

It is important that an experienced surgical team are involved in dealing with patients with painful artificial joints.

What sets us apart

The Team Approach

Hip and knee replacement surgery is on the rise in the UK and we are seeing many younger patients requiring this type of surgery to ensure freedom from pain and a full range of movement. Over 80,000 hip replacements and 80,000 knee replacements are performed annually in the UK and approximately one in ten are secondary procedures, with evidence that revision surgery is increasing.

When treating troublesome joint replacements, as well as an experienced surgeon, the support of a team is vital, including infection experts, radiologists and specialist nurses. Thorough and comprehensive teamwork and planning is vital for successful revision surgery. Mr Philip Mitchell and Mr Simon Bridle have spent many years working with their team, both in their NHS and private practice, dealing with complex revision cases.

When choosing a surgeon for a revision joint replacement procedure it is essential they are specially trained in this type of surgery, are supported by a multidisciplinary team, regularly perform complex procedures and are able to show good outcomes in their patients.

Identifying why artificial joints become painful can be difficult, requiring special investigations, including blood tests, X rays and scans to find the problem. It is important that the correct diagnosis is made before surgery is undertaken, so an experienced team is important.

Revision surgery of a total hip or knee replacement procedure can be a challenging procedure that requires either some or all the components of the artificial prosthesis to be removed and replaced. The orthopaedic surgeon must be careful to cause minimal damage to the bone and surrounding tissues when removing the components or the material that was used to fix the prosthesis.

Failure of the joint will often lead to bone loss, which may need a bone graft, or the use of special implants to replace the damaged bone. Complex reconstruction where the bone has been badly damaged can be very demanding and should only be done by surgeons experienced in these techniques.

If infection has occurred a team approach is vital, to confirm the diagnosis and plan treatment in conjunction with infection experts.

Surgery is required either with one operation, although sometimes a two-stage procedure may be required, with a temporary spacer used in the joint until the infection has been cleared before a new replacement joint is inserted. Infection should only be treated by teams experienced in this field.


“When he performed the op on my leg/hip back in 2015, Mr Mitchell said that he would hope to have me in a position where I could do the walks which we enjoy doing within two years. That seemed like an awfully long time at the time! We have just returned from a walking safari in Zambia – I haven’t felt strong enough in my leg to go before now. We were on and off little river boats, climbing through the undergrowth to view animals, walking quite a long way… and all was fine. I don’t think I have quite as much flexibility in my joint as the real thing, but it’s not far off, and it’s tons better than before the op. I think that bit is more a matter of confidence, which I’m still working on. So, a big thank you to Mr Mitchell and Mr Bridle, I am very grateful!”

G.P.Hip Revision Surgery

“When I first met Mr Mitchell, I was in my third year in a wheelchair and anticipated that, because of continuous difficulty in walking, I faced a future similarly limited. Mr Mitchell’s advice though was that the replacing of both my hips would be beneficial in general terms, given what the X-rays showed, and would undoubtedly help with my walking. I am extremely pleased to confirm that my general health has improved significantly and that my walking, though still limited, has made the use of my wheelchair a thing of the past. It must be most gratifying for you to see what dramatic changes can be brought about in the lives of your patients as a consequence of your professional skills. I would like to add that your caring approach helped me in a difficult period of my life, as I feel certain it has done for so many of your other patients.”

G.A.Double Hip Replacement

“My hip is amazing and I get very little trouble from living an active life with our young children – we were able to surprise the children with a trip to Lapland to find Santa this Christmas. Thank you both so much for all your help and care.”

N.B.Hip Replacement Surgery

Professional Organisations

Get in Touch

To arrange a consultation with Mr Bridle or Mr Mitchell, please call their private secretaries on the numbers listed below or fill in the contact form and one of the team will be in touch.

Mr Bridle’s Private Secretary: Diana Vergara
020 8947 9524 | bridle@fortiusclinic.com

Mr Mitchell’s Private Secretary: Zoe Murfitt
01737 356411 | zoe.murfitt@mekon.com