Spinal fusion is one of the most common surgeries in America. There are now more of these procedures performed each year than even hip replacements. But there are concerns that some doctors are performing fusions that are unnecessary and even dangerous. The procedure joins two or more adjacent vertebrae, often with metal rods and screws, and can result in paralysis or life-threatening complications. For decades, patients have had no insight into how likely their doctor is to recommend a spinal fusion, or whether they may be performing risky procedures that others would not consider appropriate. They had no way of knowing how many spinal fusions their doctor performed over a given period, what percentage of patients they performed the procedure on, or how those numbers compared to their peers. This story made much of that information public for the first time. For this six month investigation, we obtained a database of previously unreleased government records. It showed how many spinal fusions each surgeon in the country performed on Medicare patients, under the billing codes most commonly used for “degenerative” conditions like simple back pain. Experts said this is where the vast majority of unnecessary fusions occur. We analyzed the data and found that some doctors performed more than ten times the national average of these fusions. Overall, 5% of the surgeons performed 40% of the fusions on four or more vertebrae — which are riskier for the patient but more lucrative for the surgeon. We also investigated outliers in the data, like Dr. David McCord of Nashville, Tennessee. He performed fusions on a higher percentage of his patients than almost any surgeon in the country. A confidential report showed he was also permanently banned from operating at one hospital in 2012, after a review found he was performing unnecessary spine surgeries. In the late 1990s, the same hospital forced Dr. McCord to limit his number of surgeries and get second opinions before operating. Dr. Omar Jimenez of Scottsbluff, Nebraska performed the third most spinal fusions nationwide. A confidential report showed that in 2006, he was suspended indefinitely by a network of five hospitals in Georgia, due to concerns about his procedure selection. Dr. Jimenez settled two malpractice suits in Georgia for a total of more than $1.3 million, according to the state’s medical board. Dr. Richard Hynes of Melbourne, Florida performed the third most fusions on four or more vertebrae in the country. He was dropped by a private health insurer from its coverage network in 2006 after it determined that he was too aggressive with treatment. From 2005-2012, five payments were made to former patients of Dr. Hynes by his malpractice insurance company totaling more than half a million dollars. Three of the cases challenged the necessity of the spinal procedures performed by Dr. Hynes. Dr. Mathew Alexander of Corpus Christi, Texas performed the sixth most fusions on four or more vertebrae in the country. He fused six vertebrae and the skull of one woman, and now her head is permanently stuck in a crooked position, looking down and off to the right. She is suing him for allegedly performing a far more invasive surgery than necessary. In addition to our broad analysis and investigations of individual outliers, we put the database online, made it easily searchable by patients, and provided guidance from experts on how to interpret it.