Frank Smith, 50, a motor dealer, of Canberra Place, Tangmere, was sentenced after pleading guilty to causing grievous bodily harm with intent, to his ex-partner at her home in Pulborough in October 2018.
He was sentenced n Tuesday (Julyt 23) at Lewes Crown Court. The court and prosecution accepted his plea to grievous bodily harm on day two of the trial.
The woman, who is in her forties, sustained a broken neck in several places, facial injuries and bruises and is still undergoing treatment 10 months later.
Detective Constable Lee Turner of the West Sussex Safeguarding Investigations Unit said: "This was a distressing assault causing life changing injuries to the victim. The investigation was complex and I am pleased that justice has been done for her.
"As well as the nine-year sentence, the court also gave Smith a Restraining Order to last indefinitely, prohibiting him from having contact with the victim or asking anyone else to contact her on his behalf.
"Anyone in such a concerning situation can be confident in contacting us at any time and arranging to talk in confidence to experienced investigators, either online or by calling 101."
For information on sources of advice and support on domestic abuse, also see the Sussex Police website.