More than a dozen physicians representing two hospitals have been named as defendants in federal lawsuits that allege they acted in bad faith by allowing a spine surgeon to perform surgery at the hospitals. The doctors in question served on the committees that approved surgical privileges at Avera Sacred Heart and Lewis & Clark Specialty Hospital, both in Yankton, according to the lawsuits. The doctors are accused of extending Dr. Allen Sossan privileges to perform complex spine surgeries, despite knowing that Sossan had a history of performing unnecessary surgeries and unprofessional conduct. Both Avera Sacred Heart and Lewis & Clark also are defendants.