Two major studies by Queen Mary University of London, University of Oxford and the University of Bristol, have found that robotic-assisted hip and knee replacement does not reduce the overall early risk of repeat surgery compared with conventional surgery.
Published in BMJ, the two studies analysed more than one million joint replacements recorded in the National Joint Registry between 2018 and 2024. Together, they provide the largest real-world evaluation to date of whether the greater technical precision offered by robotic assistance translates into better outcomes for patients.
The researchers found that, despite robotic technology being designed to help surgeons position joint implants more accurately, this did not translate into a lower overall early risk of repeat surgery after either hip or knee replacement.
Robotic surgery has been designed to help surgeons perform hip and knee replacements by placing the implants more accurately. This better implant positioning is hoped to reduce the risk of repeat surgery in both the early years after surgery and in the longer term as well as improving how well the joint works. The findings come as the NHS plans a major expansion of robotic surgery, aiming to increase the number of procedures sevenfold by 2035. The technology requires substantial investment, with robotic systems costing around £1 million to introduce and adding between £1000 to £2,500 to the cost of each procedure.
In robotic-assisted joint replacement, the surgeon remains in control of the operation, using computer and robotic technology to help plan and guide the placement of implant. Robotic systems are intended to improve the accuracy of implant positioning, but the studies suggest that greater technical precision does not necessarily translate into better overall early outcomes for patients.
With the hip study, the team found no overall reduction in repeat surgery or mortality associated with robotic surgery. However, it did find that robotic hip replacement was associated with lower risk of surgery for problems related to implant malpositioning. This specific benefit did not translate into overall reduction in the need for repeat surgery. With the knee study, there were no differences in repeat surgery risk observed. The study compares early outcomes and longer-term follow-up will be needed to establish whether the differences in implant survival emerge over time.
The researchers from the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS) University of Oxford, Queen Mary University of London, and the University of Bristol, used a method known as target trial emulation to analyse large-scale real-world registry data. This statistical approach is designed to make comparisons between groups more closely resemble those of clinical trial by balancing patients according to known differences in their characteristics.
Mr Hasan MOHAMMAD, Academic Clinical Lecturer in Trauma and Orthopaedics at Queen Mary and lead author of the study said: "This study which uses novel methodology and represents the largest real-world analysis of its kind worldwide, provides important independent evidence for patients, surgeons and policymakers at a time when robotic hip and knee replacement surgery is being adopted rapidly. New technology should deliver meaningful benefit for patients and represent good value for a publicly funded health service."
