The policy allows a maximum of (two) diagnostic joint sessions, unilateral or bilateral. A positive diagnostic response is defined as ≥75% sustained and constant pain relief for the duration of the local anesthetic and ≥75% sustained and constant pain relief for the duration of the anti-inflammatory steroid) was measured by the same pain scale at baseline.

Diagnostic accuracy is improved with dual injections. However a single block may be sufficient because the next step in the algorithm would be therapeutic injection which could also be a confirmatory injection, therefore the policy allows this option. The confirmatory/therapeutic injection must meet the criteria for improvement as outlined in the policy before a subsequent injection can be considered.