Arsenal released a statement on Aaron Ramsey's condition. He underwent surgery for a broken tibia and fibula.
"The operation successfully reduced the fractures and whilst it is too soon to state an exact timescale for recovery, Aaron will certainly miss the remainder of this season."
This being Arsenal there are no shortage of examples of how players have made it back to the field after potential career ending injuries. Ramsey can look to Eduardo and Abou Diaby for inspiration.
We don't know if this was an open fracture which means if it broke the skin or whether it was a clean break without a wound. Open fractures are surgical emergencies that require management of infection to the wound site through regular irrigation, debridement and antibiotics. Once that danger is averted then surgical options can be considered depending on the instability of the fracture.
After surgery there will be arduous months spent undegoing rehabilitation with gradual weight bearing, mobilization, and strengthening exercises as part of the regime. If there are no complications he should be back for the start of next season. Speedy recovery to you, Aaron!