Did Naruto ever get arm back?
When Naruto returned to the town, Lady Tsunade analyzed his lost Arm and Wounds. She mended them and arranged a prosthetic arm for Naruto. His left arm was damaged in final fight with Naruto as well as Naruto’s Right Arm. Naruto got a new arm but Sasuke still did not get a new arm.
How did Naruto’s arm come back?
Sasuke lost left arm as he used chidori with left and naruto lost his Right arm as he used the rasengan with right. After they returned to the Leaf Village Tsunade implanted Hashirama’s cells into Naruto’s lost arm and created a “perfect prosthetic arm full movement and feeling too.