A 35-year-old farmer from rural Maharashtra presents 6 hours after a penetrating injury to his left leg caused by a rusty farm implement. On examination, there is a 2 cm punctate wound over the medial tibial shaft with minimal external bleeding. Probing reveals the wound tract extends deep into the muscle. Plain radiographs show a simple tibial fracture with no comminution. The limb is neurovascularly intact. Which Gustilo type best describes this injury, and what is the most appropriate next step?