According to the Department of Justice, the matter relates to the payment of kickbacks in return for referrals of patients to Pacific Hospital for spinal surgeries and other services, which were paid for primarily through the California workers' compensation system.
Read more here: http://www.healthcarefinancenews.com/news/more-doctors-indicted-15-year-long-580-million-kickback-scheme-pacific-hospital-long-beach.