"Further testing revealed that Cam Newton has two transverse process fractures in his lower back and no further internal injuries," the Panthers said in a statement Tuesday afternoon.
"Right now we have thought about Cam's well-being and we understand there was someone else in the other car who was injured," the team said. "We just hope that they're all OK."
Newton was expected to be released from the hospital on Wednesday after undergoing tests.
On Wednesday, the Charlotte Mecklenburg Police Department confirmed that Newton will face no charges for Tuesday's wreck and was traveling at the posted 35 mph when the other driver pulled out in front of him.
The injury suffered to Newton is the same back injury that Dallas Cowboys quarterback Tony Romo suffered earlier this season. Romo missed one game this season for the injury, however no timetable was given for how long Newton will be out, if at all.
The accident took place around 12:30 p.m. ET, according to Charlotte police. Both Newton and the driver of the other vehicle were taken to the hospital with non-life-threatening injuries.
Panthers general manager Dave Gettleman confirmed in a telephone interview from Texas that Newton had not been released Wednesday morning.
Gettleman said he still has no details of what happened or when Newton would return to action.
The GM was at the league owners' meeting in Irving, Texas, on Tuesday when he received a call from his office about the crash.
"I'm just thankful he was wearing a seat belt and everyone involved is all right," Gettleman said before boarding a plane back to Charlotte.
The Panthers earlier said Newton will be held overnight for observation but that the franchise quarterback was "in fair condition and undergoing tests at Carolinas Medical Center."
Team owner Jerry Richardson earlier told the Charlotte Observer that Newton is "in good shape," after speaking with CMC doctors.
Newton, 25, was conscious when he was transported to the hospital, a source told ESPN's Ed Werder.
A witness told the Charlotte Observer that Newton was "alert" but "in pain" at the scene of the accident.
In his fourth season, the former No. 1 overall pick has thrown for 2,812 yards, run for 425 yards and accounted for 19 total touchdowns this season (16 passing, three rushing) to go along with 11 interceptions for a Panthers team that remains in the hunt for the NFC South division title despite a 4-8-1 record.
If Newton is ruled unable to play, veteran Derek Anderson would be expected to take over as Carolina's starting quarterback. Anderson led the Panthers to a 20-14 victory over the Tampa Bay Buccaneers in Week 1 while Newton sat out with fractured ribs.
The Panthers play the Bucs this Sunday at 1 p.m. ET.
ESPN.com Panthers reporter David Newton and The Associated Press contributed to this report.