Unequal limb length (acquired), unspecified site

This code signifies a measurable difference in the length of a patient's limbs that developed after birth, without specifying which limb or the underlying cause. It indicates an acquired discrepancy in limb length, rather than a congenital anomaly.

Use this code when documentation clearly states an acquired unequal limb length but does not specify the affected limb (e.g., "patient presents with acquired limb length discrepancy"). This code is appropriate when the laterality or specific limb involved is not documented or is unknown.

• Avoid using this code if the specific limb (e.g., right leg, left arm) is documented; instead, use a more specific M21.7- subcategory.
• Always search for an underlying cause (e.g., fracture malunion, poliomyelitis sequelae) and code it first if known and clinically relevant.
• This code is for acquired conditions; congenital limb length discrepancies are coded elsewhere (e.g., Q72.-, Q73.-, Q74.-).