Subjective: Longitudinal deficiency of a digital ray of the hand except rays 1 or 5Comments:
The threshold for this deficiency should be that all of the phalanges of a central ray (not F1 or F5) are absent and at least part of the associated metacarpal (if it is just the phalanges that are missing, this should be coded as Absent finger). The absence of a central ray or rays frequently yields a cleft appearance of the hand. This term is preferred to ectrodactyly of the hand as this has been used (more appropriately) for forms of phalangeal hypoplasia or amputation but it is acknowledged that this is a commonly used term. Lobster claw deformity is neither descriptive nor acceptable due to its pejorative nature. There is wide variation in the hands of affected individuals, but the common factor seems to be the absence of the central ray, justifying the use of Split hand as a clinical designation.