At interviews you will be asked about your research, some will ask specifically about ortho research. My only publication is in a completely unrelated field. Most interviewers thought that was interesting and asked me about it. But, this is because I had no idea I was interested in ortho until after clinical rotations third year.
If you are thinking ortho at this point it will only help you to dive into an ortho project, since most other specialties won't care what your research is in, you might as well satisfy that checkbox for the most competitive field so it's there if you go through with ortho. Again, it's not essential. If you have a 260+, all honors, AOA, then programs for the most part don't care if you don't have multiple ortho publications. You'll just want to be involved in at least one ortho project that you can talk intelligently about.