Studies have shown that injections into the knee when given within three months of total knee replacement increase the risk of infection after replacement of the knee. Richardson and colleagues studied risk of joint infection on the basis of the type of medication injected. Patients undergoing knee replacement were selected from a nationwide private insurer database. Pre-operative injections were identified and were associated with Medicare codes for corticosteroid or hyaluronic acid. Patients who received both types of injections a year before total knee replacement were excluded. The outcome of interest was infection of the total knee if it occurred less than three months following total knee replacement. The risk of infection was compared between groups of no injection, corticosteroid injection and hyaluronic acid injection, and between patients who received single or multiple injections. Statistical analysis was performed.
A total of 58,337 patients underwent total knee replacement during this study. 5.6% received hyaluronic acid, and 28.6% received corticosteroid. The overall infection rate was 2.74% in the no injection group. There was an increased risk of infection in knees injected with either medication less than three months before total knee replacement. There was no increased risk of infection with injections given greater than three months before total knee replacement. Direct comparison of corticosteroid and hyaluronic acid show no significant difference between medications or between single and multiple injections.
In conclusion, preoperative corticosteroid or hyaluronic acid injections administered to three months before total knee replacement increased the risk of infection after the operation. However, there was no difference in infection risk between medications or between multiple or single injections. On the basis of these data, it is recommended to avoid both injection types in the three months prior to total knee replacement.
Richardson SS, Schairer WW, Sculco TP, Sculco PK.
J Bone Joint Surg Am. 2019 Jan 16;101(2):112-118.