My Husband Stepped On A Nail About 5 Months Ago

My husband stepped on a nail about 5 months ago and he swears it hit the bone. It was sore for some time and then he had no issues with up until a couple weeks ago when it began aching. The ache is in the same spot where the nail punctured his foot. Over the last couple weeks the ache has slowly spread up to his knee. Could this be osteomyelitis?