Wisconsin-based ProHealth Care has bought a minority interest in the Orthopaedic Surgery Center in Waukesha from Orthopaedic Associates of Wisconsin. The joint venture should allow ProHealth, which includes Waukesha Memorial Hospital, and Orthopaedic Associates of Wisconsin to work more closely on scheduling surgeries, standardizing equipment, and quality initiatives, said Ed Olson, chief executive of Waukesha Memorial. It also is an example of ProHealth's strategy of partnering with independent physician practices, Olson said.