* Biomet to buy Johnson & Johnson wrist repair system
* J&J-Synthes deal should close within the week
* Transaction valued at around $21 billion
WASHINGTON, June 11 (Reuters) - Johnson & Johnson has won U.S. antitrust approval to buy Swiss medical device company Synthes Inc if it sells some assets, the Federal Trade Commission said on Monday.
Johnson & Johnson will sell its system for surgically treating serious wrist fractures, and related assets, to Biomet Inc as a requirement for approval, the FTC said.
European antitrust officials approved Johnson & Johnson's deal to buy Synthes, valued at about $21 billion, on April 19.
Johnson & Johnson and Synthes together have about 70 percent of the market for plating systems used to surgically repair fractures in the radius bone nearest the wrist, the FTC said.
Such injuries often occur when a falling person tries to catch himself or herself.
"J&J and Synthes are direct competitors for these important systems used in the surgical treatment of traumatic wrist fractures," said Richard Feinstein, director of the FTC's Bureau of Competition.
The deal should close within the week.
"We are pleased with the FTC's clearance of our acquisition of Synthes and look forward to moving ahead to closing," said Johnson & Johnson spokesman Alfred Wasilewski.
Biomet's plan to acquire DePuy Orthopaedics, the Johnson & Johnson unit that includes its surgical wrist fracture repair business, was announced in April. The deal was valued at $280 million in cash, Biomet said at the time.