Do not attempt to get out of a probation hearing by having someone stab you. Your body does not enjoy having hard, sharp, pointy objects going into places where there has been no provided orifice, and it is likely to make this fact known to you through making you scream in pain. Also, odds are you're not going to get out of the hearing, and when the judge finds out, he is likely to be dumbstruck by your breathtaking escapade. This means that, in addition to jail, odds are you will also need some level of medical attention, at which point you will get treated on by a doctor who knows going in that you convinced someone to give you stab wounds to get out of a probation hearing.
There is also, of course, the small risk of your accomplice not being able to stab to wound as opposed to stabbing to kill. If one is not an experienced stabber, this can easily happen, at which point the police may have some fairly difficult questions for your accomplice.