PHF is the third most common appendicular fracture. Non-operative treatment can lead to nonunion which causes pain and functional impairment. Operative treatment is recommended to avoid poor outcomes from delayed intervention. The study analyzed 2230 PHF cases to identify risk factors for nonunion. It found a 10% nonunion rate, with 18% nonunion for fractures with valgus head angulation and 12% for neutral or varus angulation. Variables like head-shaft angle ≤1400, head-shaft translation, varus deformity, and metaphyseal comminution were associated with higher nonunion risk. Older age, female sex, comorbidities, osteoporosis, and smoking also