* EU regulator set to accept J&J concessions in trauma devices
* Approval could come before EU's April 26 deadline
* $21.3 bln deal is J&J's biggest acquisition
By Foo Yun Chee
BRUSSELS, March 15 (Reuters) - Johnson & Johnson is set to gain EU approval for its planned $21.3 billion buy of Swiss medical devices maker Synthes after offering concessions to address concerns over its dominance in trauma devices, a person familiar with the matter said on Thursday.
J&J wants Synthes, its largest ever acquisition, to boost its orthopaedics franchise and submitted its proposals to the European Commission last month.
"The deal will be cleared by the Commission," said the person who declined to be identified because of the sensitivity of the matter.
The EU executive, which is scheduled to decide by April 26 whether to approve the takeover, could issue a decision earlier than that deadline, the person said.
A second person with direct knowledge of the case said J&J's concessions related to trauma products which are used to treat bone fractures. Neither J&J nor the Commission provided details on the proposals.
The Commission opened an in-depth investigation in November last year, saying it wanted to make sure that rivals would still be able to compete effectively once the deal is completed.
Medical devices and diagnostics accounted for two fifths of J&J's turnover in 2010. It competes with Stryker and Zimmer.