CAMDEN, N.J. – New Jersey Gov. Jon Corzine remained in critical but stable condition on a ventilator Monday afternoon after a third operation on his thighbone, and pleased his doctors by moving his arms and legs on command.

“There’s been some questions about that, especially the left leg, the injured limb,” said Dr. Robert F. Ostrum, the head of orthopedic trauma who performed the governor’s surgeries at Cooper University Hospital.

“He was able to bend and straighten his knee, and move his foot up and down, which to me is a good sign that all of the nerves and the muscles are working,” he said.

Meanwhile, authorities stayed quiet on the progress of the crash investigation, even rejecting questions about how long it is expected to last.

State police Superintendent Joseph “Rick” Fuentes would not say how fast Corzine’s state police driver was going or why he was using the truck’s flashing lights as he headed north on the Garden State Parkway. One motorist has told investigators that he mistook the lights for a vehicle responding to an emergency; his attempt to get out of the way contributed to the crash, police have said.

Fuentes also would not disclose state police regulations on the use of such lights.

“I’m going to hold off all comments on that until I can see an analysis,” he said after a news conference to discuss flooding in parts of the state.

On Monday night, Corzine, 60, remained unable to speak, his vital signs steady, in the intensive-care unit. In addition to the 40-minute surgery, doctors inserted tubes near his right lung and in the wounded leg to drain fluid.

Dr. Steven Ross, head of Cooper’s trauma division, said a scan Monday showed no signs of a clot in the leg, and the governor continues to be free of infection and pneumonia, life-threatening complications in patients with his type of injuries. Those setbacks could develop at any time. “I don’t say patients are out of the woods until they leave the hospital. He’s certainly not out of the woods yet,” Ross said.

During the weekend, doctors had discussed the possibility of taking Corzine off the breathing equipment Monday. But by late afternoon, that was not the plan.

The governor “will come off the ventilator when he is ready,” Ross said. “I’ve been at this long enough to know not to make those predictions, so I won’t make them.”

The tube in his trachea would be removed only if he were comfortable enough to breathe on his own. In addition to the thighbone, or femur, the governor broke 12 ribs, his clavicle, sternum and a lower vertebra. “His lungs are working properly,” Ross said.

The governor also suffered cuts to his head, but appeared to have normal brain function, doctors said. On the Glasgow coma scale – a measure of neurological function – Corzine rated an 11 of 13 points, they said. Eleven is the highest level achievable for a patient who, because of intubation, cannot speak.

He is receiving nutrition from a feeding tube, the surgeons said, and physical therapists have started some level of treatment. The governor will face months of rehabilitation.

“As far as the leg, he’s got a long haul ahead of him,” Ostrum said.

The first surgery was Thursday night, to set the bone with a rod and screws. On Saturday and Monday, he underwent planned procedures to remove dead quadriceps and hamstring muscle. Ostrum said he removed a “large amount” of fluid Monday. No more surgeries were scheduled.