From the CPT Assistant, this describes radius & ulna...but would apply to medial & lateral malleolous:
Removal of Separate Plate/Screw Systems-Both Bone Forearm Fracture
Code 20680 is reported once for each bone when removing internal fixation of healing fractures of "both bones" (radius and ulna) of the forearm when each bone is treated with separate plates and screws. If the plate and screw system is removed from the ulna at the same session as the radius, code 20680 with modifier 59 appended is reported. These plates may be described by size (eg, small fragment system or small fragment plate) or by a trademark or type (eg, locking plate, periarticular plate, or polyaxial locking plate). Alternatively, the hardware may be described by the name of the manufacturer. Each plate and screw system removal procedure would be reported separately using code 20680 with modifier 59 appended to denote distinct procedural services (eg, different site or separate incision) performed on the same day by the same physician. Removal of any and all screws used for each fixation system (ie, one plate and its associated screws) is part of the service of the plate removal.