MotoGP medical director Angel Charte said the rider would be transferred to Barcelona for further scans.
"Our initial thoughts are that it won't be surgery, but we can't know until we have the MRI (scans)," he told the MotoGP website. "He's okay but in a lot of pain and unable to move."
Lorenzo is 15th in the standings after crashing out of the previous race in Spain and taking several frontrunners with him, including Ducati's title contender Andrea Dovizioso and Yamaha's Valentino Rossi.
He has 19 points after seven races while team mate and reigning world champion Marc Marquez leads the championship on 140 points.
(Reporting by Alan Baldwin in London, editing by Christian Radnedge)