It's early to comment on the bone regeneration. However from the xray I can deduce that the nature of the injury must be severe.
Next Steps
I believe that the current intervention may not be enough and he may have to undergo further surgery like bone transport using Ilizarov fixator. However I will have to see the current condition of the leg and the current circumstances before arriving at any decision. The surgeon has done a good job till now.
Health Tips
Please ensure he does proper physio to keep the knee and ankle joint supple and the strength of the hip and knee.