It is the second time he has broken his leg while playing for United, having broken his right leg in the 2001/02 Humber derby win over Hull.
He went under the surgeons knife on Tuesday, and could be playing again by the turn of the year.
Iron boss Brian Laws told the Press Association: "The club will not see him wrong, we had already offered him a new deal. We were waiting to sort it out at the end of the season, he's not going to be destitute.
"All breaks are bad, but the doctors have told us it's as clean as it can get and Richard is talking about trying to get back playing before Christmas, so that's five or six months.
"We will make sure he will be employed by this club. He will be here and will be well looked after until he starts playing again."