A few of my period medical instruments contain a single ratchet. Sometimes, people looking at my instruments make a blanket statement that ratchets are indicia of post-war instruments but that is not correct.
Not all medical instruments with ratchet locks are post-Civil War. Multiple ratchets are, indeed, post-Civil War developments but single ratcheted instruments were manufactured and used by the original cast. See, e.g., Vol. I, No. 2 Confederate States Medical and Surgical Journal (February, 1864), p. 22, which has an illustration of bullet forceps containing a "ratchet arrangement to prevent the blades from slipping." I do not know the extent to which such medical instruments were used in the field. However, I thought the acknowledgment of such instruments by a Confederate journal was noteworthy and I wanted to share it with colleagues.
The illustration also contains two other instruments useful in detecting the ball in a gun-shot wound. One we are familiar with, namely, the Nelaton probe. Another, a sliding detector, was something I was not familiar with. (Also, the illustration of the Nelaton probe is interesting - at least to me - because it is not the double-tipped wire device that most of us have seen. This one contains what looks like an ebony handle at one end and the porcelain tip looks larger than the tips I've seen in the field.)
The accompanying article on detecting and removing a ball is interesting, too.