2015 ISAKOS Biennial Congress ePoster #1401

Patient Reported Outcome of Total Knee Replacement Surgery in the Uk - A Report of 88,000 Patients

Andrew J. Price, DPhil, FRCS(Orth), Oxford, Oxfordshire UNITED KINGDOM
William Jackson, FRCS(Orth), MD, Oxford UNITED KINGDOM
Nicholas Bottomley, MBBS, FRCS, Oxford, Oxon UNITED KINGDOM
Kristina Harris, MSc UNITED KINGDOM
David J. Beard, MA, MSc, DPhil, FRCS(Hon), Prof., Oxford, Oxfordshire UNITED KINGDOM

Nuffield Orthopaedic Centre, Oxford, UNITED KINGDOM

FDA Status Cleared

Summary: TKR has a very large treatment effect and the majority of patients report very good outcomes after surgery, but 15% of patients report continued pain and abnormal function after surgery however only 50% of these feel they are worse or no better off after surgery.

ePoster Not Provided



The development and collection of population based outcome data on Total knee replacement in the UK has offered a new perspective of the effectiveness of TKR treatment in the NHS. This paper examines the relationship between PROM scores, dissatisfaction and subjective improvement after surgery, to determine a treatment effect and the extent of good/poor outcomes after TKR.


We have used the UK National PROMs database for this work. For total knee patients Oxford Knee Score (OKS), EQ-5D, dissatisfaction and subjective improvement are all assessed routinely at 6 months after index surgery. An anonymised data set was determined, cleaned and prepared for analysis. Descriptive statistics were prepared and comparison was performed of the OKS to the anchoring questions. Treatment effect size distribution was calculated using the EQ-5D and OKS.


90% of patients had improvement in their symptoms and the mean effect size was extremely high for the vast majority of patients. There was a strong positive and significant correlation of the change in OKS to satisfaction and subjective improvement. Approximately 4% of patients had a poor outcome with, low change in PROM, dissatisfaction and a lack of improvement or deterioration in symptoms after surgery. A response shift was seen with patients gaining approximately 5 points in OKS but reporting report no improvement.

Discussion And Conclusion

Approximately 15% of patients still report significant pain and symptoms after surgery but a much smaller subgroup report no improvement or worsening of problems after TKR. In the majority of patients the treatment effect is large and TKR is shown to be a highly successful intervention. More work is required to understand the aetiology of consistent trend for poor outcome seen in a small number of patients.