ST. LOUIS — Fifty-five hospitals in 21 states have agreed to pay $34 million to the U.S. government to settle allegations that they used more expensive inpatient procedures rather than outpatient spinal surgeries to get bigger payments from Medicare, the U.S. Justice Department said Tuesday.

The settlement involves kyphoplasty procedures used to treat spinal fractures usually caused by osteoporosis. It can be done as an outpatient procedure, but he Justice Department said the hospitals performed the surgeries as inpatient procedures to increase Medicare billings.

"Hospitals that participate in the Medicare program must bill for their services accurately and honestly," Stuart F. Delery, acting Assistant Attorney General for the civil division of the Justice Department, said in a statement.