[Artificial Disc Replacement] The Relationship of Intrapsoas Nerves During a Transpsoas Approach to the Lumbar Spine: Anatomic Study

[Justin]

Journal of Spinal Disorders & Techniques. Issue: Volume 23(4), June 2010, pp 223-228

The Relationship of Intrapsoas Nerves During a Transpsoas Approach to the Lumbar Spine: Anatomic Study

Park, Daniel K. MD*; Lee, Michael J. MD†; Lin, Eric L. MD‡; Singh, Kern MD*; An, Howard S. MD*; Phillips, Frank M. MD*. Author Information: *Rush University Medical Center, Chicago, IL. †University of Washington Medical Center, Seattle, WA. ‡St Jude's Medical Center, Fullerton, CA. © 2010 Lippincott Williams & Wilkins, Inc.

Study Design: A cadaveric study.

Objective: To define the relationship of the lumbar exiting nerve root and trunks within the psoas muscle with reference to the radiographic center of the intervertebral disc, the recommended disc access point for the minimally invasive lateral transpsoas approach.

Summary of Background Data: The transpsoas approach to the lumbar intervertebral body disc is a minimally invasive approach used for interbody fusion. This approach carries the potential risk of injury to the intrapsoas nerves. There are no published studies investigating the locations of the intrapsoas neural elements with reference to the transpsoas access corridor developed during minimally invasive lateral approaches to the disc.

Methods: Ten human cadaveric specimens were analyzed. A guide wire was placed in each disc space center under lateral fluoroscopic guidance as has been recommended for disc access in the transpsoas fusion technique. Using calipers, the distances from the exiting nerve and trunk to the wire were measured.

Results: In general, the nerve trunk was a mean of 14 mm posterior to the center of the disc and was a mean of 5 mm closer to the center of the disc than the exited nerve. The trunks were closer to the center of the disc caudally in the lumbar spine, with the distance ranging from a mean of 16.4 mm at L2-3 to 10.6 mm at the L4-5 level. The intrapsoas location of the exited nerve was less variable and was greater than 15 mm from the projected center of the disc. At L4-5, the trunk approximated the center of the disc in 15% of specimens.

Conclusion: This study suggests that the intrapsoas nerves are a safe distance from the radiographic center of the intervertebral disc in a majority of cases; however, anatomic variations in the location of these nerves place them at injury risk in a small number of cases. These results suggest that neural monitoring whereas traversing the psoas may be important to enhance the safety of the transpsoas approach. Care is particularly warranted at the L4-5 level.

[christytaf]

hi,
this is exactly what I'm afraid of, and this is what if discussed with all doctors I've been to in Germany, "the injury of the nerves".
Most of them assured me that they are using neural monitoring, but isn't it a matter of experience of the surgeon too??

How much is neural monitoring actually affecting the saffety of a surgery???

Im having a Sponlylolisthesis grade 4, i would say, a "spondyloptosis", so im very concerned about what could go wrong during a Spondylodesis surgery.

[Katie]

I had XLIF surgery in March on L4/5 and L5/S1, with a grade 2 spondy on the latter.

With this procedure on the 4/5, the surgeon used a probe guided by his finger through an incision, and worked his way through the psoas muscle. The probe indicated when they were close to a nerve, and could be guided around it, which avoided any damage to the nerves. My recovery has been amazing, with a great deal less pain than most have experienced with fusion surgery.

The surgeon gave us a textbook explaining exactly how the surgery would be done, which gave us a greater understanding of the process and eased our stress. The procedure was started, I believe, by Nuvasive and my surgeon has worked closely with them in developing the procedure and hardware.

[christytaf]

Thanx so much for replying Katie, your helping so much

Is it so painful after a fusion like this????

how much time did your recovery take???