Mubasher Mehmood was jailed for his involvement in the attack, which took place in the early hours of December 27, 2019.
The 18-year-old victim was stabbed in the back while he was in his vehicle in St John Street, Wellington.
Mehmood, 25, of Windsor Road, Arleston, was jailed on Friday for his involvement in the attack after he previously pleaded guilty to assault at Stafford Crown Court.
Earlier this year, Yasar Mehmood, 34, also of Windsor Road, Arleston, was also jailed for his involvement in the attack and sentenced to 18 years.
He had also pleaded guilty to assault.
Detective Inspector Jo Whitehead, who was the officer in charge of the case, said: “This awful attack had such an impact on the local community and I’m pleased that both men have now been given significant sentences for their involvement in the attack.
"I hope it offers reassurance to the local community that police and the criminal justice system will not tolerate this type of violent behaviour.
“The life-changing injuries suffered by the victim will be with him for the rest of his life and I would like to pay tribute to him, and his family, who have worked with us throughout our investigation and helped us achieve this positive result.
“This was a challenging investigation, it couldn’t have been done without the support of the victim and their family and local communities and we are so grateful for this support.
"It is imperative that we make sure those who cause harm face the consequences of their actions.
“We will continue to do all we can to tackle street violence involving knives, there is no reason anyone should be in possession of a weapon on the street and we have teams working diligently to identify those who are carrying a knife as well as those involved in serious and organised crime.”