Consultant Orthopaedic Surgeon I Director of Orthopaedics - Knee

Mr Sam Rajaratnam

Schoen Clinic Orthopaedic and Spinal Hospital London

Consultant Orthopaedic Surgeon I Director of Orthopaedics - Knee


Mr Rajaratnam is the Director of Orthopaedics at Schoen Clinic London
Mr Rajaratnam is a leading Consultant Orthopaedic Surgeon specialising exclusively in knee surgery. He regularly treats high profile individuals and dignitaries from around the globe including international sportsmen and women and is honoured to be the chosen surgeon for numerous doctors and their families on a regular basis.

Joint replacement surgery
Mr Rajaratnam is internationally renowned as one of the leading knee replacement surgeons in the world, having performed over 4,500 knee replacements over his career (450-500 implants annually). He is passionate about improving outcomes following knee replacement surgery and achieving a faster, less painful recovery. He has assembled a world-class multidisciplinary team who work closely with him at Schoen Clinic London to deliver expert care.

The NJR, or UK National Joint Registry (the leading joint registry in the world) regularly publishes data on joint replacement surgery, closely monitoring hospital performance and Consultant specific outcomes. Mr Rajaratnam has the very best proven outcomes in the UK and amongst the lowest revision rate (failure rate) for knee replacement surgery as evidenced by the NJR.

5 year results:

10 year results:


Rapid recovery and innovation
Mr Rajaratnam has championed the concept of 'rapid recovery and enhanced pain relief' following joint replacement surgery and lectures internationally on the subject. His latest innovations in this field have been carefully developed over his extensive career and include a shorter operating time, advanced surgical techniques, multimodal anaesthesia, the use of local anaesthetic infusions and elite rehabilitation.

Mr Rajaratnam has assembled a team of Intensive Care Consultants, Anaesthetists, Specialist Nurse Practitioners, Sports & Exercise Medicine Consultants and Physiotherapists to work together to reduce pain and discomfort after knee surgery.

The latest joint replacement techniques he performs include both partial and full replacements and the use of patient-specific 3D customised alignment methods for accurate fitting of knee implants when necessary.

He is also an international authority on robotic knee replacement surgery and the ROSA® Knee System (from Zimmerbiomet). Having successfully implemented the first comercially active ROSA® Knee System for robotically assisted knee replacement surgery in the UK in December 2020 at Schoen Clinic London, Mr Rajaratnam regularly trains other surgeons on this technique.

Treatment of soft tissue knee injury
Mr Rajaratnam is a fellowship-trained Soft Tissue Knee surgeon and treats numerous professional and amateur sportsmen and women with soft tissue knee injuries. His clientele includes professional footballers, actors and high profile individuals. He has an interest in day case ACL reconstructions, and has performed approximately 1000 ACL reconstructions over his career, where patients are able to comfortably walk out of hospital within 6 hours of their operation.

He is one of the chosen surgeons for the Professional Football Association (PFA) and is on the faculty of the Isokinetic FIFA Football Medicine Conference each year.

He is excited about the advances in stem cell and biological solutions for treating appropriate cartilage defects in the knee but is very careful in selecting the appropriate patient for each new technique, so as to practice proven and transparent evidence-based medicine.

Training and awards

  • Mr Rajaratnam trained at Guy’s and St Thomas’s Hospital in London and qualified with a First Class degree in Anatomy and an MBBS in 1997.
  • Further higher surgical training via the Royal College of Surgeons - England at numerous centres of excellence in the UK and fellowship training in Knee Injury treatment in Sydney, Australia.
  • In 2006 Mr Rajaratnam was awarded the Walter Mercer Gold Medal for the best performance throughout Great Britain and Ireland in the final FRCS orthopaedics examination. This is the "most prestigious award" that a UK-trained orthopaedic surgeon can achieve, before becoming a Consultant Surgeon.
  • British Orthopaedic Association Ambassador to Hong Kong in 2007 and working in Sydney, Australia, at some of the world’s best knee injury units.
  • Appointed as a Consultant Surgeon in the UK in 2008, and now enjoys an excellent international reputation as a leading knee surgeon.
  • Mr Rajaratnam lectures internationally on advances in knee surgery and has been a Senior Trainer to the London and Kent, Sussex and Surrey Deaneries in the past training Specialist Registrars in Orthopaedic Surgery.
  • Was one of the founding surgeons setting up Schoen Clinic London in August 2018.
  • Recognised as one of the leading surgeons for knee surgery in the UK and now Director of Orthopaedics at Schoen Clinic London.

ROSA® Robotic Knee Replacement - Mr Rajaratnam discusses using robotic technology for knee replacement surgery

Watch the video to learn the driving factors behind Mr Rajaratnam's decision to utilise robotic technology; see the process, benefits and patient videos following robotically-assisted surgery. Read several patient stories below or find out more about the ROSA® Knee System here.

Patient stories - following ROSA® Robotic Knee Replacement

  • Nick, a 68-year-old avid cricket player
  • Tom, who has always led an active life and years of sport left him with no cartilage on his knee
  • Lee, an ultra-marathon runner who is back to running following a knee replacement

Recent patient feedback
"As and when I have to have my left knee done, I’m not going anywhere else other than Schoen Clinic. All wonderfully done. Sam is an absolute hero and I’m very grateful to him and the clinic for the way everyone looked after me. I just wish I could give a party to thank everybody. Thank you to everybody, I couldn’t be more grateful."

Consultant website: www.thechelseakneeclinic.com

Mr Rajaratnam's secretary direct email; rajaratnam.sec@schoen-clinic.co.uk OR self-pay patient new enquiries; selfpay-enquiries@schoen-clinic.co.uk 



  • Knee replacement surgery – total, uni-compartmental and revision
  • Soft tissue and ligament injuries of the knee – day-case ACL, PCL and multi-ligament reconstruction
  • Cartilage repair and biological solutions in the knee – including meniscal repair, joint preservation and stem cell procedures when appropriate
  • Knee surgery with the ROSA® Knee System