A 28-year-old male that sustained a closed left femoral shaft fracture 12 months ago and underwent intramedullary nailing presents with persistent pain in the right thigh. The patient walks with an antalgic gait. He denies any fevers or chills. His surgical sites are well healed and there are no signs of drainage. Serum ESR and CRP are 12 mm/hr (reference <20 mm/hr) and 0.9 mg/L (reference <2.5 mg/L), respectively. Figures A and B are the AP and lateral radiographs of the left femur. Which treatment option offers the highest chance of union and enables immediate weight-bearing?