In a case of radial head subluxation in a 2-year-old, which sign indicates successful treatment after manipulation?

In the context of radial head subluxation (also known as "nursemaid's elbow") in a 2-year-old, a key indicator of successful treatment after manipulation is when the child quickly begins to use the affected arm. This response signifies that the radial head has likely been reduced back into its normal position within the elbow joint, alleviating pain and restoring function.

Following manipulation of the injury, it is expected that the child will regain normal use of the arm almost immediately. The child may begin to move the arm without hesitation and show relief from any pain associated with the subluxation, which is a clear indication that the treatment has been effective. Observing the child engaging in activities with the arm demonstrates that the radial head is properly aligned and functioning.

The other options might suggest progress but do not directly indicate that the manipulation has been successful. For instance, while swelling might decrease and pulse/sensation restoration are important to check, they do not necessarily confirm that the radial head has been correctly repositioned. The presence of a click during arm movement may indicate that the joint is functioning but does not itself confirm successful treatment, as the click could be a normal joint sound even if the injury persists. Thus, the most reliable sign of effective treatment