Prior Surgery

“We are having difficulty with a denial when combining CPT 28320 and CPT 20680. CPT 20680 is being rejected as unbundling. According to CCI edits, CPT 28320 is a Column 1 code and CPT 20680 is a Column 2 code and they are allowed. The surgeon removed hardware from a prior surgery performed by a different surgeon not associated with the practice then repaired a non-union and applied new fixation. Is the removal of prior hardware actually included in CPT code 28320? If not, what modifier should be used if it is the same incision/surgical site as the non-union repair?”