I am not sure if I understand your question or its purpose 100% either, but I will try to give an answer. If you want to be a true orthopaedic surgeon then the only way to do it currently is a five (or six) year orthopaedic residency training program. However, as Jalby already indicated, you can do a hand fellowship after completing either a full general surgery or plastic surgery residency. To my knowledge, you have to complete your residency to pursue this option. Also, neurosurgeons operate on the spine but again this assumes you have completed a neurosurgery residency which is longer and more painful than an orthopaedic one. I doubt that there is any shorter way to be a surgeon who practices orthopaedics (even if in these scenarios it is limited to a specific body area).
There is an option out of family practice to do a sports medicine fellowship and in some manner these individuals might be considered a nonoperative orthopaedist. I dont think this option is currently available to internal medicine residents, but I cant be absolute. To clarify, this sports medicine fellowship is not the same as the one completed by orthopaedic residents as it is not a surgical fellowship. I would imagine that in the right orthopaedic group practice, a sports trained family physician would function basically as a nonoperative orthopaedist and may even have the ability to assist a true orthopaedic surgeon in cases if they so desired. This would obviously depend on the dynamic of the group, but a lot of orthopods have PAs or NPs who assist in their surgeries, and in the "good ol days" of medicine I believe it was not completely uncommon for family practitioners to assist surgeons in cases.
I dont know if this is the kind of info you wanted, but I hope it is helpful.