Spinal fusions serve as case study for debate over when certain surgeries are necessary

The rate of spinal fusion surgery has risen sixfold in the United States over the past 20 years, according to federal figures, and the expensive procedure, which involves the joining of two or more vertebrae, has become even more common than hip replacement, the Washington Post reports. More than 465,000 spinal fusions were performed in the United States in 2011, according to government data, and some experts say that a portion of them — perhaps as many as half — were performed without good reason.

The rapid rise of spinal fusions in the United States, especially for diagnoses that generally don’t require the procedure, has raised questions from experts about whether, amid medical uncertainty, the financial rewards are spurring the boom.