A drink-driver put a policeman in a headlock and lifted him by the nostrils after being pulled over, a court heard.
David Bull, 37, is accused of using "savage levels of violence" against two officers in Tavistock, Devon.
He put Sgt Dave Clarke in the "choking headlock" and dislocated another officer's knee, Plymouth Crown Court heard.
Mr Bull has admitted a count of grievous bodily harm, but denies three more charges.
The defendant, from Bedfordshire, tested more than twice the drink-drive limit, Plymouth Crown Court heard.
Nick Lewin, prosecuting, said Mr Bull had put Sgt Clarke in a "choking headlock" and lifted him off the ground by putting two fingers into his nostrils.
Giving evidence, PC Jenny Mashford wept as she told jurors about the "terrifying incident".
She told the court that her knee was dislocated during the attack and left at a 90-degree angle - requiring a year of physiotherapy.
Mr Bull, who faces four charges in total, has admitted causing grievous bodily harm to Sgt Clarke, but denies a charge of intending to do so.
He also pleaded not guilty to assaulting PC Mashford, with or without intent.
The trial continues.