For the current week, the overall ratings of three Medical Devices stocks are worse, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Given Imaging (NASDAQ:GIVN) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Given Imaging has developed a proprietary wireless imaging system that allows a medical professional to examine the gastrointestinal tract. For Portfolio Grader’s specific subcategory of Earnings Surprise, GIVN also gets an F. The stock currently has a trailing PE Ratio of 35.20. To get an in-depth look at GIVN, get Portfolio Grader’s complete analysis of GIVN stock.

The rating of Greatbatch (NYSE:GB) slips from a C to a D. Greatbatch develops and manufactures power sources, feedthroughs, and wet tantalum capacitors used in implantable medical devices. The stock gets F’s in Earnings Growth, Earnings Momentum, and Margin Growth. For a full analysis of GB stock, visit Portfolio Grader.

Tornier (NASDAQ:TRNX) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Tornier designs, outsources the manufacture of and markets orthopedic products. The stock gets F’s in Earnings Momentum and Earnings Revisions. To get an in-depth look at TRNX, get Portfolio Grader’s complete analysis of TRNX stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.