According to his team, the 23-year-old - who did not finish the race - was operated on in Herentals on Sunday night. Trentin's right hand is affected.
"Due to the complexity of the fracture, Trentin will have to observe a period of rest for four weeks, after which he may gradually return to training," explained the team website.
Meantime, Pieter Serry was taken to hospital at the conclusion of Monday's fifth stage of the Tour de Langkawi after he crashed on the downhill before the final climb to Genting Highlands.
Serry finished in 85th place, 23:12 down on stage winner Julián Arredondo (Team Nippo - De Rosa).
X-ray's discounted any fractures to Serry's left elbow which had connected with the road.
A decision was to be taken this morning as to whether he would continue the remainder of the 10 stage event.
Serry joined Omega Pharma - Quick-Step for 2013 after two seasons at Topsport Vlaanderen-Mercator. Last season he finished third in the Brabantse Pijl and 30th in Liege-Bastogne-Liege.