Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Tornier N.V. (UNKNOWN:TRNX.DL), a medical device company that manufactures joint replacement and soft tissue solutions to restore patient mobility, skyrocketed as much as 22% after reporting its second-quarter earnings results.

So what: For the quarter, it was actually more of the same for Tornier with a wider-than-expected quarterly loss of $0.28 as it ramps up its product line and begins expanding internationally with its sales. Its lower-extremities segment delivered the biggest year-over-year growth of 114%, primarily from its OrthoHelix acquisition, while its large-joint division disappointed with a 4% decline in sales. However, the real reason shares seem to be getting such a lift is the company's third-quarter and full-year guidance, which fell right in line with the Street's expectations. Looking ahead, Tornier expects to grow revenue by 13% to 16% to a range of $314 million to $322 million in fiscal 2013 (adjusted for currency exchange rates) with EBITDA of $33 million to $37 million. The Street's current revenue consensus for the year is $316.7 million.

Now what: Following multiple quarters of failing to meet expectations, the fact that sales are picking up and EBITDA is projected to remain in double-digits as a percentage of revenue (10.5% to 11.5%) is a positive sign. But, as you know, I much prefer to see bottom line results before I would ever suggest chasing a big gainer like Tornier even higher. With profitability still seemingly two or three years off and its international business -- which I see as a key to its success -- still a relatively small piece of the pie, I'd rather stick to the sidelines and watch this device maker from a distance.