Initial fears suggested the former Exeter centre-back's season could be over when he flew to Rome for the operation but the positive verdict means he will be sidelined for only the next two months.
"There has been some speculation as to how long Troy would be out of action following his surgery," Swindon physio Paul Godfrey told the club's official website.
"This was due to his recent scan not being able to state with certainty what type of surgery he would need to undergo, just that surgery was required.
"I am pleased to say that following the surgery, professor Mariani informed the club that Troy's knee was not the worst-case scenario and, in fact, (he) only had to perform a meniscal repair to re-attach and stabilize a small part of the cartilage on the inside of Troy's knee.
"As a result, we expect Troy to now need approximately eight weeks of rehab before he is fully fit again."