I'm sure having a very well known orthopod write you a GREAT letter will help you...I think in general people do seem to hold a letter in higher regard if it is written by a person known to them and who does not write letters that make every applicant sound as if they walk on water. You do not need Dr. Andrews to write you a letter however to get an interview. If you do not know the person well though, I would not ask. I don't believe a generic letter does anything for your application no matter who it is from...try to shoot for all excellent letters and if you don't feel you know three or four ortho docs well enough, I don't think it hurts to get another letter from a surg or int med attending who you know will write you an excellent one. My letters were written by the program chair, the residency director, a community (affiliated with the univ) orthopod, and and internal med doc. As people always say ortho is a very small community and in general I think program directors and residency chairs are good people to ask as most of them are familiar with each other and probably know you relatively well... I was most often asked about my letter from my home program chair on interviews. That being said I did have a community orthopod write me a letter as he trained at an istitution that I was very interested in and on that interview I felt that his letter carried the most weight since almost every interviewer asked about him..so if you have a particular place in mind and you know an attending who did residency or fellowship there, definately try to get to know them and ask for a letter. Good luck getting your letters! I remember being really worried about it this time last year because i thought i had no one to ask but as you start your ortho rotations you figure out pretty quickly who to ask and everything just falls into place.