Mequon-based Titan Spine LLC has raised another $7.5 million for its series D funding round, which now totals $15 million, according to a December SEC filing.

The interior of Titan Spine’s manufacturing plant in Brown Deer.

The funding again came entirely from Texas private equity firm Southlake Equity Group, said Tom Keene, managing partner at Southlake.

Keene said when Southlake made its initial investment of $7.5 million in June 2016, it also committed to another $7.5 million in a second tranche, which was deployed in February 2017. The SEC filing for this second investment was not filed until December. Read the full story here.