Bone regenerator
A bone regenerator was a medical device used for repairing shattered bones. Starfleet medkits typically held bone regenerators.
The bones in Benjamin Sisko's arm were shattered during the attack on the USS Honshu. When Sisko regained consciousness, he saw his arm was in a sling. Dukat, the man who had rescued Sisko during his escape from the Honshu, had found a bone regenerator in the medkit aboard their shuttlecraft, but claimed, "I'm not much of a doctor, so I just put on the cast." (DS9: "Waltz")