Debra Tongue, 46, of Baton Rouge, was suffering knee pain after an operation on torn cartilage last year, stopping her in her previously active tracks. “The pain was not going away, and it wasn’t lessening,” she said. “I knew that this is just what I have to live with.” But then her husband left the radio on, and the former personal trainer heard an ad for a possible solution to her discomfort. Doctors at Baton Rouge Orthopaedic Clinic were part of a surgical trial to test a new meniscus implant created for people like her — those who lived with pain after a common surgery for a torn meniscus.