Synthes Inc. shareholders, meeting at the company's headquarters in Solothurn, Switzerland, voted to approve the proposal by Johnson & Johnson to take over Synthes for $21.3 billion in cash and stock.
Synthes has facilities and a U.S. headquarters in Chester County. The companies hope to close the deal in the first half of 2012.
"The shareholders approved the proposal to adopt the agreement and plan of merger as outlined in the invitation," Synthes said in a statement.
The European Union is reviewing the deal to examine the antitrust effects on the market for screws, plates and other devices to fix bones broken through trauma or wear and tear.
The EU set a new deadline of April 2 to rule on the acquisition, which would be the largest in the history of J&J.