Not true about urethral injuries is -
This is very well known that in a pt. of urethral injury, catheterization is not done b/c it would convert a partial tear into a complete transection of the urethra*.
Blood at the urethral meatus is the single most important sign of urethral injury. The presence of blood at the external urethral meatus indicates that immediate urethrography is necessary to establish the diagnosis.
Bladder injury (either intraperitoneal or extraperitoneal) is associated with posterior urethral injuries.