A sadistic teenage couple tied up a 16-year-old boy and sliced through his Achilles tendons in a torture session involving "extraordinary" violence.
Daniel Grace, 19, and Shauna Smith, 17, also stabbed their victim in the leg, hit him with a hammer and punched him in the drug-fuelled attack.
The pair were yesterday jailed indefinitely by a judge who said he was worried about the future danger they posed to the public.
They attacked the youngster when he went to their home on School Crescent, Dewsbury Moor, in June last year. Peter Moulson, presecuting, said that after smoking cannabis and taking the drug mkat Grace and Smith suddenly turned on the boy.
They wrongly accused him stealing from them and told him he need to "learn some respect"
Over 30 minutes he was repeatedly punched in the face and his hands and feet were tied with belts.
He was then struck over the head with a hacksaw and stabbed in the thigh with a kitchen knife and had his head stamped on.
The victim lapsed in and out on consciousness during the attack but recalled being dragged from the living room to the bedroom.
Mr Moulson said: "He saw and felt Smith hold his feet up. Grace began to cut his Achilles tendons on both ankles. He was also hit in the ribs with a crowbar, hit to the head with a screwdriver and had hot wax poured upon him."
He was gagged with a sock and Grace and Smith threatened to pour acid on him before putting him in a sleeping bag and securing it with wire.
The victim was freed when he woke to find other people in the flat untying him.
After he escaped, emergency services found one of his tendons was completely severed. He had both legs put in plaster and was in a wheelchair for three weeks.
He was also left with scarring from the stab wounds and has had nightmares since the attack.
Grace and Smith both pleaded guilty to false imprisonment and wounding with intent.
Leeds Crown Court heard they had criminal records for violence, including assault and robbery.
Robin Freize, for Grace, described the attack as "wicked" with a worry element of sadism.
He said: "The pernicious influence of the drug mkat played a large part in this."
Andrew Dallas, for Smith, said she pleaded guilty to the offence at the earliest opportunity. He said this offence was "in a league of its own". He said she suffered from a disorder in which people commit offences in groups and it was uncertain whether she would grow out of it.
Mr Dallas said Smith was attending courses in New Hall prison to address her behaviour.
Judge James Goss lifted reporting restrictions to allowing Smith to be identified. He said: "This is an extraordinary case of extreme seriousness. The public has a right to know about this case and about the consequences."
He told Grace and Smith they must serve a minimum of three years in prison before being considered for release, but it could be much longer.
He said: "It is not only alarming for what happened, it is alarming for the future.
"If you are capable of that level of vioelnce of one occasion, there is the significant risk that you will do it again."