Stevens went under the knife after a slower than anticipated recovery from surgery earlier this year.
He has not played for England since the world champions' Six Nations Championship defeat against France last March.
Stevens, capped 10 times, faces a six-week recuperation period before beginning his rehabilitation programme.
He will be monitored by Bath and England medical teams, but he looks like missing November appointments with New Zealand, Argentina and South Africa (twice) at Twickenham.
Stevens' latest injury setback will be a huge blow to England head coach Andy Robinson.
Robinson views Stevens as an integral part of his World Cup plans in France next year.
The South Africa-born forward has already shown during his fledgling Test career that he possesses the ability to enjoy a long international career, but injuries have stalled his progress.