What Factors Determine Revision and Patient Satisfaction?


A recent study from Liddle, A. et al1 has examined the factors affecting revision, patient-reported outcome and satisfaction following PKA looking at data from the NJR (National Joint Registry) for England, Wales and Northern Ireland and the Hospital Episode Statistics database.

Reduced Revision in High Volume Hospitals and Older Patients

The study found the overall survival rate of PKRs to be 91.8% at 5 years and 89.1% at 8 years in a cohort of 25,982 patients. Implant survival was better in older patients (≥75 years), men and those with no co-morbidities. Revision was also less likely if performed in high PKR volume hospitals by experienced surgeons; there was no difference in survival between a cemented or cementless PKR.

This aligns two important studies:

  1. Tregonning et al.2 reviewed data from the New Zealand Joint Registry from January 2000 to December 2005, and found that surgeons performing at least 12 PKRs per year are found to have a decreased revision rate.
  2. Liddle et al.3 (also the author of this study) reviewed data from the National Joint Registry, of 41,986 patients, which showed that surgeons utilising PKA for under 20% of their annual knee replacements experienced a dramatic increase in their revision rate.

High Levels of Patient Satisfaction

Over 84% of patients had good, very good or excellent levels of satisfaction, with only 3.8% reporting poor satisfaction. Those with procedures performed by more experienced surgeons and in higher volume hospitals tended to not only have reduced revision rate, as mentioned above, but those patients were also more satisfied following surgery than those who had their procedures from lower volume surgeons.


Older patients, who are less likely to receive a UKR, are the patients who appear to gain the greatest benefit from surgery and the lowest revision rates. Superior results in survivorship and patient satisfaction appear in patients operated by experienced surgeons in high UKR volume hospitals.


Note: Studies referenced herein include several variations of partial knee type and design.
  1. Liddle, A.D et al. Determinants of revision and functional outcome following unicompartmental knee replacement. Osteoarthritis and Cartilage 22 (2014) 1241e1250
  2. Tregonning et al. Early failure of the oxford phase 3 cemented medial uni-compartmental Knee joint arthroplasty: an audit of the nz joint registry over six years. J Bone Joint Surg Br 2009 vol. 91-B no. SUPP II 339
  3. Liddle, AD et al. Optimal usage of Unicompartmental Knee Replacement: A study of 41,986 patients from the National Joint Registry for England and Wales. ISAR Annual Meeting 2013.


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