Kirner’s deformity (hunchbacked pinky) and A3 shortness of finger are both hereditary pinky deformities, but they are two completely different diseases: 1. Kirner’s deformity has a palmar and radial curvature of the end phalanges, with the end phalanges showing the signature hunchback hook bend deformity; A3 short finger disease has normal development of the end phalanges themselves, but the middle phalanges are short and radially deviated, resulting in radial deviation of the end phalanges of the little finger. 3, nail appearance: Kirner deformity nail is hooked nail deformity; A3 type short finger disease nail is normal. 4, surgical correction site: Kirner deformity finger is the correction of the terminal phalanges; A3 type short finger disease is the correction of the middle phalanges.