Wilkinson is optimistic he may recover earlier than the end of March
Newcastle say Jonny Wilkinson is on course to make a successful comeback after undergoing a second operation on the knee he dislocated in September.
The fly-half, 29, had further surgery two weeks ago to determine the success of the initial operation.
Falcons director of rugby Steve Bates reported Wilkinson had been cleared for the next stage of his rehabilitation.
"That has a timescale all of its own, but at least the initial hurdle seems to have been overcome," he said.
Wilkinson will now work on strengthening his knee and making sure it has the required flexibility before proceeding further.
"There was always going to be a little doubt about whether the original operation had been a success, as with all operations," Bates added.
"Now that we are hopefully past that stage, it's just a case of continually monitoring how he progresses, rather than now giving a timescale of when he will be back playing."
When he underwent the initial surgery in early October, Wilkinson's knee specialist envisaged a recovery period of five months, meaning he is unlikely to figure in the Six Nations in February and March.
Wilkinson, an eternal optimist despite his catalogue of injury trauma, said earlier this month that he hoped he might recover in time to figure in the championship.
He last played international rugby nine months ago when he replaced Toby Flood during the 33-10 victory over Ireland and has seen Danny Cipriani and Flood take over England fly-half duties during the second half of this year.
Wilkinson has been plagued by injuries since landing the drop-goal that won England the World Cup in 2003.
He had only played four games after returning from shoulder surgery before suffering the latest injury against Gloucester on 30 September.