Need another reason to keep your weight under control?

Excess weight can cause dislocation of your knee and may even lead to a complication that results in amputation of your leg. A new study attributes a surge in dislocated knees to the U.S. obesity epidemic. “Obesity greatly increases the complications and costs of care,” said study lead author Dr. Joey Johnson, an orthopedic trauma fellow at Brown University’s Warren Alpert Medical School. “As the rate of obesity increases, the rate of knee dislocations increases. The total number of patients who are obese is increasing, so we are seeing more of these problems,” Johnson explained. Knee dislocations result from multiple torn ligaments. Vehicle crashes or contact sports, such as football, are common causes. For the study, the researchers analyzed more than 19,000 knee dislocations nationwide between 2000 and 2012. Over that time, people who were obese or severely obese represented a growing share of knee dislocation patients — 19 percent in 2012, up from 8 percent in 2000. Obesity is also linked to more severe knee dislocations, longer hospital stays and higher treatment costs, according to the study published recently in the Journal of Orthopaedic Trauma.