INSPIRED SPINE: OLLIF and Risk of Nerve Root Irritation

1. During the office consultation and immediately prior to surgery, the patient is always informed and consents that he or she understands that there is 15% risk of nerve root irritation associated with the OLLIF procedure. This risk decreases substantially with the surgeon’s experience, and is diminished by the decreasing the number of passes required to enter the disc space during the surgery (more than 3 passes to enter the disc space significantly increases the likelihood of creating this irritation).

2. Typically, nerve root irritation mostly occurs in the L5/S1 approach due to the angle of this approach.

3. As compared to open fusion approach, OLLIF has a 50% lower probability of nerve root irritation. Nevertheless, because OLLIF patients have less other post-operative symptomatic pains versus open spinal fusion patients, we may mistakenly conclude that nerve root irritation occurs more frequently in OLLIF patients versus open fusion patients. However, because open surgery patients have so much other post-operative pain, they complain less about numbness as it is their least of their problems. OLLIF patients, on the other hand, typically are doing so well that numbness is their ONLY source of post-operative discomfort. Comprehensive reviews of OLLIF patient outcomes have demonstrated that this procedure is actually less risky with respect to post-operative nerve root irritation. A review of the picture above where the OLLIF and TLIF approaches are compared demonstrates why.

4. The irritation is mostly L5 numbness and tingling, but it could be neuropathic in nature with a burning sensation or even weakness; and it can include a complete nerve loss of function up to neuropraxia although this is rare.

5. The irritation can become worse for 3-4 days when post-surgical swelling increases before it plateaus.

6. An epidural steroid injection is always performed in the surgery which can mask some of the symptoms such as pain, so a delayed appearance of the nerve irritation is possible.

7. Patients always do more at home than in the hospital (even if they don’t do much), so always expect some of the symptoms to get worse 3-7 days after the patient is discharged.

8. People with significant prior nerve damage, or diabetic neuropathy or who have been on Gabapentin are at a higher risk for this irritation.

9. The prognosis is excellent usually 4-8 weeks after surgery with the patient starting to feel better. The symptoms often start with an electricity-like jolt for few seconds shooting down the leg. This symptom often worsens for few days or weeks, after which the symptoms start improving. Nerves are analogous to electrical wires as just before they connect, sparks fly; hence these “jolts” experienced by the patient are a good sign and indicate the nerves are making a connection and are about to heal.

10. Supportive measures are the way to go: pain management,
epidural steroid injection or even nerve root injection (although be careful not to inject directly into the nerve root. Generally approach to L5/S1 foramen, as discussed above, is somewhat tricky, so ESI is sufficient),
Medrole dose pack,
Gabapentin if the problem lasts more than 2 weeks (many don’t); if on Gabapentin, increase 900mg TID
assurance and open discussion about this phenomenon.

11. Obviously always review a CT scan to rule out other complications; MRI is less helpful in acute phase because of all of the post OP changes and meta .

As seen in following video this patient is describing the symptoms well. Lets talk about this case: