Lumbar spinal fusions are among the most challenging procedures to code, partly because the anatomy is difficult to conceptualize and due to the variety of approaches and combinations of procedures that can be done.
Let’s focus on fusion of the anterior column of the lumbar spine. That’s fusion of the joint (yes, the disc forms a “lower joint”) between the vertebral bodies. Whenever you see an “interbody fusion” you know you’re looking at an anterior column spinal fusion.
The interbody operative site can be reached in a number of ways. PLIF (posterior lumber interbody fusion) and TLIF (transforaminal lumbar interbody fusion) are pretty intuitively coded as posterior approaches to the anterior column. The patient is prone and the instruments and implants are inserted via an incision in the back and through the posterior column of the patient's spine to reach the anterior column. No confusion there.
ALIF (anterior lumber interbody fusion) is clearly anterior approach. The patient is supine, instrumentation and implants go through the anterior of the body and directly into the anterior vertebral column.
Lateral approaches include XLIF (extreme lateral interbody fusion) and DLIF (direct lateral interbody fusion). For these the patient is positioned on their side and the instrumentation and implants are placed in laterally. Both are also known as "transpsoas fusions". The psoas muscle originates at the transverse processes and is the muscle which is penetrated to access the spine for fusions done by these approaches.
In actuality XLIF and DLIF are essentially the same approach but with different, proprietary retractors and nerve monitoring techniques. The vendors of the hardware for these two techniques:
- Nuvasive for XLIF
- Medtronic for DLIF
The crucial part is that the anterior approach is done anteriorly to the transverse process which demarcates the anterior and posterior columns of the spine itself. The other way I like to think about it is that the instrumentation is not inserted through any other part of the spine (i.e. posterior column) but goes directly to the anterior column.
AxiaLIF approach actually punches the fusion components through vertebral body adjacent to the level being fused – usually L5-S1. The incision is made adjacent to the coccyx on the patient’s posterior but the fusion components are not placed through the posterior column of the spine. In this case the clearly posterior incision takes precedence in selecting the approach as “posterior”.
Naturally the ICD-10 index and tabular gives us no help in selecting the approach from the acronyms PLIF, ALIF, XLIF, etc. If you have your old ICD-9 book around you can refer to 81.06 and 81.08 for the acronyms.
Be advised that ICD-9 Coding Clinic, Second Quarter 2009 Page: 3 calls DLIF, XLIF, and AxiaLIF all posterior approaches. In Coding Clinic, Fourth Quarter 2010 Page: 125 the DLIF and XLIF were moved to the anterior approach, which is the logic used in the explanation above. We may or may not receive specific ICD-10 guidance on this subject but I suspect it will remain as-is regarding the approach.
Senior Managing Consultant of HIM Optimization Facility Coding for Healthcare Resource Group, Inc.
Ed O’Beirne PA, MHS, CCS, CDIP is an ICD-10 educator of providers and coders with a specialization in procedure coding ICD-10-PCS and CPT. Before joining HRG, Ed was a director of physician assistants and patient relations for an 80k visit a year ER, a physician assistant in emergency medicine for over 10 years, coding supervisor, auditor and consultant for 9 years and EMT and respiratory therapist for 5 years.