The reference material I refer to is from the 'Ortho Pink Sheet April, 2009, Vol. 10, No. 4 (Ask Margie)' that states in short; refer to the 5th digit of the ICD-9 manual if the 5th digit is a 3 that includes the forearm, radius, ulna, wrist joint; if the 5th digit is a 4 that includes the hand, carpus, metacarpus , phalanges. and likewise the ankle/foot...ie, see page 959 in the 2012 ICD-9-CM (check out the box).