Former Stryker (NYSE:SYK) CEO Stephen MacMillan’s departure from the company may have come as the result of an extramarital affair with a former company employee, according to a report in the Wall Street Journal.

The paper reported that MacMillan resigned from the Kalamazoo, Mich.-based medical device company on February 8th after losing the confidence of some "key members" of the company’s board, who had becomed concerned about alleged relationship the 48-year-old executive had with an ex-employee.

MacMillan abruptly resigned from the world’s largest orthopedics device maker this month citing family reasons. Stryker revealed to stock analysts shortly thereafter that he was romantically involved with a former employee, the Journal reported, citing anonymous sources that have not yet been independently verified.

MacMillan’s decision left many scratching their heads when the announcement was made. Stryker officials insisted that his resignation had nothing to do with his performance in the corner office, but was related only to personal reasons that began late last year.

MacMillan’s wife, Amy, filed for divorce in September, 2011, according to the newspaper. They’ve been married in 1987.

In addition to ceding the corner office at Stryker, MacMillan stepped down from Texas Instruments’ board of directors this month and there is no word yet on whether he will retain his upcoming chairman role at AdvaMed, the medical device’s industry council.

Stryker agreed to a hefty severance package for the outgoing executive, including $5.5 million in cash at the end of this month and an option to purchase nearly $65 million worth of company stock, among other perks.

Stryker CFO Curt Hartman, will serve as the interim CEO while the company looks for a permanent successor to MacMillan, who had the job for 7 years and signs off officially on Wednesday. William Parfet, the board’s lead independent director, was named the non-executive chairman to replace MacMillan on the board.

Stryker has declined all comment on the matter, telling MassDevice that the company "won’t be taking any interviews on this topic and have no further comments."

MacMillan’s next move may be to a post at a private-equity firm, according to the Journal.