A 55-year-old man from Mumbai falls backward while stepping off a bus and lands on his palm with the wrist flexed forward. He presents with severe pain, swelling, and a deformity described as 'reverse dinner fork' on the volar aspect of the wrist. X-ray confirms a fracture of the distal radius with volar angulation and volar displacement of the distal fragment. Which of the following is the most appropriate initial management for this fracture?