Hewitt, 23, went under the knife today (Friday) in Manchester for corrective surgery.
The Newport-born speedster missed the start of this season – and had to pull out of the summer tour with Wales – after dislocating his shoulder in training and requiring initial surgery.
However, following further assessment during his rehabilitation and specialist advice, Hewitt has now had a further operation.
Hewitt – who made his regional debut in 2013 and has scored 21 tries in 72 games for Dragons - will now commence a period of rehabilitation as he looks to return to full training in the Spring.