Genzyme Corp., the drugmaker bought by Sanofi-Aventis SA this month, sued Zimmer Holdings Inc. and Anika Therapeutics Inc. alleging the companies’ treatments for arthritic knee pain infringe a patent.

Genzyme is seeking to block sales of Anika’s Monovisc drug as well as a treatment made by Seikagaku Corp. and distributed by Zimmer called Gel-One, according to two patent-infringement lawsuits filed Tuesday in federal court in Boston. Genzyme, based in Cambridge, Mass., also is seeking cash compensation.

The company filed the lawsuits the same day it was issued the patent for a method of treating a knee joint with a single injection of hyaluronic acid, which the company markets as Synvisc-One, according to the complaint. Sales of Synvisc-One and of Synvisc, a three-injection drug, rose 20 percent to $393 million last year, Genzyme said in its annual report.

Synvisc-One was the only single-injection treatment approved by U.S. regulators until Gel-One was approved March 22, according to the complaint against Warsaw-based Zimmer. Tokyo-based Seikagaku also was named in the Zimmer lawsuit.

Anika, based in Bedford, Mass., sells Monovisc in Europe, Turkey and Canada, and is seeking approval to sell it in the United States. Anika has “already begun advertising for field sales representatives,” Genzyme said in that complaint.

Zimmer spokesman Garry Clark said the company doesn’t comment on pending litigation. Officials with Anika didn’t immediately return messages seeking comment.

Paris-based Sanofi bought Genzyme, the world’s largest maker of medicines for rare genetic disorders, for at least $20.1 billion.