Albert Barnes Commentary Proverbs 25:19

"Confidence in an unfaithful man in time of trouble Is [like] a broken tooth, and a foot out of joint." — Proverbs 25:19 (ASV)

Emphasis should be placed on the uselessness of the “broken tooth” and the “foot out of joint,” or tottering, rather than on the pain connected with them. The King James Version loses the emphasis and point of the Hebrew by inverting the original order, which is “a broken ... joint is confidence,” etc.