First, I'd like to second what Dunce said - basic science almost always requires a much greater time commitment than clincial research. Some will argue that it takes a lot of effort to recruit subjects and so forth. But on the whole, most clinical papers are chart reviews of some sort, and these can be done quickly.
As an example, to my chagrin, at my last job, the new intern got his 1st publication after 4 months on the job, when I had to work for 3 years before I got my first. His was clinical, mine was basic science. Neither was 'better,' and both are needed. Clinical may be more readily understandable to a clinician, or he may find that basic science stuff impressive. In the end, it's all a wash.
OP - Profs may push you towards basic science because they want the cheap labor. As with any job opportunity, your boss's motivations are not only different than your's, but they may be counter-productive to your's. Understand this before commiting to anything.
Jack P - Look back my post about the field of research. It helps if it's in your field of interest, but it doesn't hurt if you did something different. That 'low impact factor' crap is for guys shooting to get tenure before they turn 35 (assuming you're producing quality work). Do what you can in the time you have left, but don't kill yourself over impact factors and what journal it's in. You're already ahead of the game.
I'll tell you, I'm all about ortho. But if tomorrow I was, say, on the psych ward, and I had the opportunity to do some chart review, I'd do it in a heartbeat. Why? Because when I'm in that interview chair, I'll have no problem telling the PD that I saw something that I thought was relevant and should be known to the medical community. The more times you do you publish, the better you get at it, regardless of the subject matter.