Re: Wang CK, Ng CY. Accessory flexor carpi ulnaris: a rare cause of distal ulnar nerve compression. J Hand Surg Eur. 2021, 46: 197–9

Before assessing a novel muscle in the hand, please be very careful

“…To accept nerve compression by the variant muscle, hypertrophy of the muscle should exist, and thus narrowing the canal through which the nerve passes. Muscle variation should be considered as a predisposing factor that could provoke nerve compression [2,3]. Moreover, in the presented cadaver case, no medical history was proven.…”

“…Therefore, to my opinion, presented in that way this statement is very speculative. It should be noted that the existing anatomical variation near the nerve generally does not mean entrapment [3]. To accept nerve compression by the variant muscle, hypertrophy of the muscle should exist, and thus narrowing the canal through which the nerve passes.…”