NEW YORK (AP) — Spinal device maker NuVasive says Chairman and CEO Alex Lukianov resigned after the board concluded he didn't follow expense reimbursement and personnel policies. The company, which makes products used in minimally-invasive spine surgeries, said Lukianov didn't live up to its standards but that the amounts of money involved don't appear to be large enough to affect its financial results. Needham & Co.