It is now extremely common for physicians to perform a combined anterior and posterior lumbar arthrodesis during the same surgical session. The anterior fusion is performed first and during this procedure the physician typically places the cage with bone graft. You would report the anterior lumbar arthrodesis code 22558, cage placement 22853 and the applicable bone graft code(s) based on the type(s) of bone graft used. Normally a separate plate is not placed.
The patient is then flipped over for the posterior arthrodesis. The lateral portions of the vertebra are decorticated, bone graft is placed followed by the posterior instrumentation. Report 22612 for the posterior arthrodesis, 22840 for posterior instrumentation and only report bone graft codes if the type of bone graft placed posteriorly is different from that type of bone graft used anteriorly. The reason for that is only one bone graft code may be reported per surgical session.
Many physicians and billing companies alike will also want to add modifier -58 (staged procedure) to the posterior lumbar arthrodesis procedure but per CPT Assistant this is an inappropriate use of that modifier in this setting.
Don’t be overwhelmed by the dictation or number of procedures being performed. If you can code an anterior lumbar arthrodesis and a posterior lumbar arthrodesis then you should have no problems coding for both services during this type of combined procedure.