Is it safe for patients to drive after intra-articular knee injection?

Intra-articular knee injection is a central component in the current management of knee pain. While this is a routinely performed outpatient procedure, institutional policies for driving post injection differ. This study examines brake response times (BRTs) before and after intra-articular knee injection. Our hypothesis is that BRTs would not significantly differ and thus patients driving ability/safety is unaffected.

Forty-five patients previously listed for right intra-articular knee injection were prospectively evaluated. Patients underwent baseline assessment of BRT prior to injection. All patients received 10 ml of fluid consisting of one milliliter of 10 mg/ml triamcinolone mixed with nine milliliters of 0.5% levobupivacaine. BRT was re-examined on the same day prior to discharge home. Pre- and post-injection BRTs were examined using the same machine and assessor.

The mean age of the cohort was 64.0 ± 12.4 and compromised of 37.8% males. There was no significant difference in the mean pre- and post-injection braking time (0.83 ± 0.29 vs 0.78 ± 0.30 s, p = .42), or in the rate of failed braking time (11.1% vs 6.7%, p = .46).

This study found that BRT did not significantly differ before and after the intra-articular injection, nor did it cause an increased number of patients failing their BRTs. These findings suggest patients should not be prevented from driving after intra-articular knee injection.