The 19-year-old went down in a heap following a late challenge by Ryan Shawcross, who was shown a straight red card.
SKY Sports, who were screening the Premier League match live, decided not to show a replay of the incident because it was 'upsetting'.
Horror: Arsenal's Aaron Ramsey (C) reacts after breaking his leg during their English Premier League soccer match against Stoke City in Stoke
The Welshman was carried off on a stretcher after his ankle buckled under contact with Shawcross, who had taken a heavy touch and stretched for the ball.
Other players showed immediate concern and some were visibly distressed.
Shawcross himself, who was sent off without hesitation by Walton, appeared to leave the field in tears.
Concern: Stoke City's Glenn Whelan (centre) waves for urgent medical attention as Arsenal's Aaron Ramsey lies injured
Arsenal regained their composure to take advantage of the extra man to record a 3-1 victory at the Britannia Stadium.
Fabregas scored the second goal from the penalty spot and made a gesture to his leg as he celebrated in front of the visiting supporters.
Agony: Arsenal's Eduardo in pain following the tackle from Birmingham's Martin Taylor
The incident occurred just over two years after Arsenal striker Eduardo, on the bench tonight, suffered a badly broken leg at Birmingham.
Arsenal closed the gap to three points on Premier League leaders Chelsea, who earlier lost 4-2 to Manchester City.
Tears: Ryan Shawcross of Stoke City is consoled by team mate Thomas Sorensen as he leaves the pitch after being sent off for a challenge on Aaron Ramsey
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Explore more:People:Martin Taylor, Cesc Fabregas, Ryan Shawcross, Thomas SorensenPlaces:BirminghamOrganisations:English Premier League