A man broke both his ankles after he jumped from a first-floor window to escape from burglars armed with knives.
The 38-year-old was hiding in his bathroom at his home in Brinklow in Warwickshire with his wife and child when three men broke in on Wednesday.
Police said the burglars ransacked the house before finding the family and then stealing an amount of cash.
The injured man is being treated at Coventry's University Hospital, police added.
He had managed to raise the alarm with a neighbour.
Describing the incident as a "terrifying ordeal" for the family, Det Con Neil Morley-Smith said the man might have suffered permanent injuries.
He said: "This was a terrifying ordeal for this young family, within the security of their own home.
"In attempting to raise the alarm to protect his family the husband has sustained serious and probably permanent injuries.
"The burglars have shown that they are prepared to use violence and it is vital that we find out who they are. We appeal to anyone with any information, no matter how small, to contact Rugby CID.
"Thankfully incidents such as this are not common in Warwickshire, and we believe the burglars may have had a specific purpose in targeting this property."
The men are believed to have driven off in a white hatchback car, possibly an Audi A3, along Coventry Road in the direction of Combe Abbey.