SpineUniverse Case Study Library

Acute Onset of Back and Left Leg Pain


The patient is a 52-year-old male with the acute onset of back and left anterior thigh pain for 2 weeks. Pain is unresponsive to oral steroids and nonsteroidal anti-inflammatory drugs.

His hypertension is treated with metoprolol. Other medications are Advil® and Vicodin®.


  • Full strength except left quadriceps: 4/5
  • Decreased left knee reflex
  • Positive left-side femoral stretch
  • Negative bilateral straight leg raise
  • The patient ambulates with a cane

Pretreatment Imaging

Give the patient's pain, quadriceps' weakness and loss of knee reflex, MRI studies were obtained. Figures 1 (Sagittal T2 MRI),  2 (Axial T2 MRI) and 3 (Axial T1 MRI) are below.

Figure 1. Sagittal T2 MRI. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 2. Axial T2 MRI. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 3. Axial T1 MRI. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.


The lumbar MRIs demonstrate a large left L3-L4 herniated nucleus pulposus with severe compression of the L3 nerve root.

Suggest Treatment

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Selected Treatment

Based on the patient's severe pain, abnormal neurological examination and concordant positive MRI findings, a surgical intervention was recommended.

A minimally invasive left L3-L4 far lateral/extraforaminal laminectomy and discectomy was performed through an 18mm tubular retractor. Blood loss was 10cc.

As illustrated in this case, the minimally invasive far lateral approach provides:

  • A direct corridor to the disc fragment with minimal bleeding
  • Affords easy identification of important bony landmarks, including the transverse process (TP), lateral facet, nerve root, and disc (Figure 4)
  • Spares the facet complex, substantially reducing the risk of postoperative instability

Figure 4. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 5. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 6. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Surgeons' Discussion Points

Far lateral disc herniations tend to be exquisitely painful due to compression of the ganglion by the disc fragment.

Three surgical approaches exist:

1. Laminectomy and facetectomy (medial to lateral)

  • Pro: Familiar approach to all spine surgeons
  • Cons: Extensive soft tissue dissection, requires resection of a large portion of the facet complex, potentially leading to instability

2. Far lateral (Wiltse) approach

  • Pros: Minimal tissue dissection through the natural plane between the multifidus and longissimus muscles, spares the facet complex
  • Cons: Less familiar approach, can be associated with bleeding if tissue planes are difficult to identify, few landmarks

3. Parsectomy

  • Pro: Limited biomechanical data suggest it does not lead to instability
  • Cons: Little data available, nerve root directly beneath the area of bone resection, unfamiliar to most surgeons


The patient experienced immediate resolution of leg pain and was discharged home the same surgical day. His motor strength return to normal by the 2 week postoperative visit.

Case Discussion

The rare incidence of extreme or far lateral disc herniations at 1.7%1 makes an effective and easily mastered solution somewhat elusive. The abundance of midline, lateral and foraminal herniations makes the surgical algorithm and approach much more refined. The standard open discectomy approach is not only effective, but well tolerated by the patient and physician. This pathology and approach is also amendable to a progression of less invasive measures, including mini-open, microscopic, tubular, and ultimately endoscopic approaches.

Far lateral or extreme lateral herniations, however, are much more difficult to treat in an open fashion. In cases such as this, a minimally invasive approach is ideal. For surgeons comfortable doing discograms and K-wire based dilation—such as OLIF, the far lateral approach is familiar. At L3-L4 the iliac crest is not a concern as it can be at L4-L5 and certainly at L5-S1. Another advantage for a far lateral approach at this level is that it does not require reaming of the lateral portion of the superior articular process. This patient does have some facet arthropathy and moderately short pedicles, which can impede access.

Not surprisingly, a recent Cochrane Review2 noted the expected benefits of minimally invasive (MIS) discectomy in many studies. Anatomically a case such as this is certainly well suited to an MIS approach. Specifically, I would favor the tubular retractor-based approach the authors performed because of the broad size of the herniation and significant pre-operative deficits. The authors are to be commended on an excellent clinical outcome.

Abdullah AF, Ditto EW 3rd, Byrd EB, Williams R. Extreme-lateral lumbar disc herniations. Clinical syndrome and special problems of diagnosis. J. Neurosurg. 1974. Aug;42(2):229-234.

Rasouli MR, Rahimi-Movaghar V, Shokraneh F, Moradi-Lakeh M, Chou R. Minimally invasive discectomy versus microdiscectomy/open discectomy for symptomatic lumbar disc herniation. Cochrane Database Syst Rev. 2014 Sep 4;9:CD010328.

Community Case Discussion (1 comment)

SpineUniverse invites spine professionals to share their thoughts on this case.

This case illustrates a very neat and typical example of an extraforaminal disc herniation.

The way the surgeons treated this case, i.e., tubular microscopic extraforaminal approach enables the surgeon to reach the area in a less invasive way (than the Wiltse approach), visualize the landmarks clearly (transverse processes, lateral aspects of the facet joint), identify the exiting nerve root, remove the disc fragment under direct vision, then check the nerve after decompression.
Thus, the technique described here is elegant, safe, and less invasive (than the traditional methods), I believe.

However, the tubular microscopic approach is not the least invasive way of removing that fragment.

The first choice as the surgical treatment of this type of herniation would be the posterolateral full-endoscopic approach, in my practice. A-rigid, 8 mm endoscope in diameter (working under water-irrigation) enables the surgeon to visualize the area clearly and remove the disc fragment with the least possible collateral damage.

In this method, the skin incision (less than 10 mm) is made 6-10 cm lateral to the mid-line (based on the patient's size), and the endoscope is inserted with 45 degrees angle to the Kambin's safe triangle under fluoroscopic control. The safe triangle is bordered medially by the the lateral aspect of the facet joint/dura/traversing nerve root, caudally by the superior border of the caudal vertebra, and laterally (the hypotenuse) by the exiting nerve root. This is the area that the extruded disc fragment is found and removed. The procedure is extremely quick and safe enough in experienced hands.

However, one of the negative aspect of the endoscopic approach is its "blindness" to the compressed exiting root during initial phase of the insertion of the endoscope. The "safe" triangle is occupied by the disc fragment, and it is safe to dock the endoscope's working cannula there in most cases.
On the other hand, the triangle may be "unsafe" sometimes. It may be distorted by the disc fragment, occupied by an aberrant nerve (furcal nerve), radicular artery, or the compressed exiting root itself. Thus, the initial "docking" phase of the endoscopic approach (which is blind) may injure the exiting root, causing a painful dysestesia, the most feared complication of this approach. Luckily, experience and meticulous surgical technique can minimize this risk.

Another cons of the endoscopic approach is its limited ability to detect whether removal of the disc herniation is complete and if the nerve is decompressed enough. Thus, although small, there is a risk of persistent pain after surgery. The patient should be informed about those risks.

In conclusion, given that the patient acknowledges and accepts above-mentioned limitations, my personal choice for this case would be posterolateral full-endoscopic approach, as the least invasive surgery for this type of disc herniation. However, I acknowledge the tubular microscopic extraforaminal approach as a very safe and less-invasive approach in this case and congratulate the authors for this well-executed surgery and the good outcome.


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