A 35-year-old male presents with a 6-week history of progressive ankle pain and swelling following a fall from height onto a dorsiflexed foot. X-ray imaging shows a fracture through the neck of the talus. On follow-up imaging at 8 weeks, a subchondral radiolucency is noted under the talar dome on the anteroposterior view. The structure marked **B** (Talus + Subtalar Joint) is the site of injury. What is the clinical significance of the subchondral radiolucency finding in this case?