April 23 (Reuters) - U.S. orthopedic implant maker Stryker Corp reported a 77 percent drop in first-quarter net profit on Wednesday as higher expenses offset a 5 percent rise in sales.

Quarterly net earnings fell to $70 million, or 18 cents per share, compared with $304 million, or 79 cents a share, a year earlier. Net sales rose 5.3 percent to $2.31 billion.

The company said research and development expenses rose 16 percent in the quarter, selling, general and administrative expenses rose 32 percent and intangibles amortization rose 41 percent.

Excluding items such as product recall and acquisition charges, Stryker said it earned $1.06 per share, a decrease of 3 percent from a year earlier.

Stryker said it still expects full-year 2014 sales growth in the range of 4.5 percent to 6 percent and adjusted earnings per share of $4.75 to $4.90, excluding amortization of intangible assets.

Shares of Stryker, which closed at $78.39 on the New York Stock Exchange on Wednesday, were unchanged after hours.

(Reporting by Deena Beasley; Editing by Leslie Adler)