Eddie - Yes, it can be very helpful to do an externship at the institution you are interested in. In fact, I would highly recommend that you rotate through the programs that you are interested in because Ortho is a difficult match. By the way, I'm positive that 9/12 residents in Orthopedics at NYU are not DOs. Keep in mind that Orthopedics is a difficult match for US MDs as well. Many of the applicants to the field have either solid board scores, are AOA, have connections, attend a prestigious medical school (Harvard, Hopkins, UCSF, etc.), or have a combination of the above. Like Tim said, you should also look into the Osteopathic Orthopedic Surgery programs as well as the Allopathic ones. I know of two DOs who went through the Orthopedic Surgery program at UC Davis. Being from CA, you might want to take a look at that program as well.