Medical-device maker Biomet halted its plans for a public offering to instead agree to be purchased by Zimmer, another medical-products maker. Biomet, known for its artificial hips and knees, was taken private in 2007 by four leading private-equity sponsors. Zimmer is paying $13.3 billion for the majority of Biomet. PE firms bought Biomet in 2007 for $11 billion. Health-care merger activity remains vibrant. This time, PE firms found a strategic - rather than financial - buyer.