Abstract
Total knee arthroplasty (TKA) remains a safe and effective intervention for the treatment of arthritis of the knee. It does, however, carry risks including death. Studies have compared the incidence of death following TKA to standardised mortality ratios of matched populations. This often suggests that TKA is protective to health in the immediate post operative phase, attributed to the lower incidence of co-morbidities in patients undergoing surgery.
In an attempt to remove this “well patient effect”, we compared the incidence of death in the first 30 and 90 days following primary TKA to that of a comparable population added to a waiting list for the same procedure.
All primary TKAs undertaken, and all patients added to a waiting list for the same procedure, in a single unit between 2000 and 2007 were recorded. Death rates at 30 and 90 days were compared in each group.
The 30 and 90 day mortality following primary TKA were 0.295% and 0.565% respectively, compared to a 30 and 90 day mortality of 0.055% and 0.316% seen in a population of patients awaiting operation. When stratified for age, surgery conferred an excess surgical mortality in all age groups over the age of 60. Factors associated with an increased mortality following operation include male gender and increasing age.
Previous studies have suggested that TKA is associated with a decreased risk of death. This study demonstrates an increased risk of death associated with surgery in comparison to a similar population deemed fit enough to undergo operation. Primary TKA carries an excess surgical mortality of 0.24% at 30 days and 0.25% at 90 days, a 5.36 and 1.79 times greater risk of death when compared to patients awaiting the same procedure.
This information will greatly assist orthopaedic surgeons when counselling patients as to the risks of surgery.
