• Journal of Korean Neurosurgical Society
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• v.42 no.1
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• pp.11-15
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• 2007

Objective : Lumbar foraminal stenosis is an important etiology of lumbar radicular symptomatology and frequent causes of remained symptoms after decompressive surgery. This study was conducted to determine the precise clinical and radiologic diagnosis of lumbar foraminal stenosis, and to demonstrate thorough treatment by decompressive surgery using a minimally invasive technique. Methods : Seven patients with established unilateral lumbar foraminal stenosis according to clinical and radiologic diagnosis were retrospectively studied. All patients underwent combined interlaminar and paraisthmic procedure with partial facetectomy. The outcome of surgery was evaluated and classified into excellent, good, fair and poor. Results : The results were excellent in four patients, good in two, and fair in one during the follow-up. There were no surgery-related complications. Conclusion : Minimally invasive combined interlaminar and paraisthmic approach provides good outcome in carefully selected patients with symptomatic lumbar foraminal stenosis.

• Journal of Korean Neurosurgical Society
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• v.60 no.4
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• pp.465-470
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• 2017

Objective : Magnetic resonance imaging (MRI) grading systems using sagittal images are useful for evaluation of lumbar foraminal stenosis. We evaluated whether such a grading system is useful as a diagnostic tool for surgery. Methods : Between July 2014 and June 2015, 99 consecutive patients underwent unilateral lumbar foraminotomy for lumbar foraminal stenosis. Surgically confirmed foraminal stenosis and the contralateral, asymptomatic neuroforamen were assessed based on a 4-point MRI grading system. Two experienced researchers independently evaluated the MR sagittal images. Interobserver agreement and intraobserver agreement were analyzed using ${\kappa}$ statistics. Results : The mean age of patients (54 women, 45 men) was 62.5 years. A total of 101 levels (202 neuroforamens) were evaluated. MRI grades for operated neuroforamens were as follows : Grade 0 in 0.99%, Grade 1 in 5.28%, Grade 2 in 14.85%, and Grade 3 in 78.88%. Interobserver agreement was moderate for operated neuroforamens (${\kappa}=0.511$) and good for asymptomatic neuroforamens (${\kappa}=0.696$). Intraobserver agreement by reader 1 for operated neuroforamens was good (${\kappa}=0.776$) and that for asymptomatic neuroforamens was very good (${\kappa}=0.831$). In terms of lumbar level, interobserver agreement for L5-S1 (${\kappa}=0.313$, fair) was relatively lower than the other level (${\kappa}=0.804$, very good). Conclusion : MRI grading system for lumbar foraminal stenosis is thought to be useful as a diagnostic tool for surgery in the lumbar spine; however, it is less reliable for symptomatic L5-S1 foraminal stenosis than for other levels. Thus, various clinical factors as well as the MRI grading system are required for surgical decision-making.

• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.320-322
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• 2005

A 45-year-old man presented with lower back pain and pain in the right leg of 3years duration. A plain radiographic examination revealed grade I isthmic spondylolisthesis, with instability at L4-5. Computed tomography and magnetic resonance imaging demonstrated bilateral foraminal stenosis, with soft foraminal disc herniation on the right side at the L4-5 level. He underwent anterior lumbar interbody fusion[ALIF] with percutaneous posterior fixation[PF] at the L4-5 level. Without removing the posterior bony structures, removal of foraminal disc herniation and reduction of spondylolisthesis were successfully performed using ALIF with percutaneous PF. When there is no hard disc herniation or lateral recess stenosis, ALIF with percutaneous PF can be one of the treatment options for isthmic spondylolisthesis, even in the presence of foraminal disc herniation, as in our case.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.224-234
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• 2023

Magnetic resonance imaging (MRI) is a standard imaging modality for diagnosing spinal stenosis, which is a common degenerative disorder in the elderly population. Standardized interpretation of spinal MRI for diagnosing and grading the severity of spinal stenosis is necessary to ensure correct communication with clinicians and to conduct clinical research. In this review, we revisit the Lee grading system for central canal and neural foraminal stenosis of the cervical and lumbar spine, which are based on the pathophysiology and radiologic findings of spinal stenosis.

• The Korean Journal of Pain
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• v.32 no.3
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• pp.147-159
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• 2019

Lumbar foraminal pathology causing entrapment of neurovascular contents and radicular symptoms are commonly associated with foraminal stenosis. Foraminal neuropathy can also be derived from inflammation of the neighboring lateral recess or extraforaminal spaces. Conservative and interventional therapies have been used for the treatment of foraminal inflammation, fibrotic adhesion, and pain. This update reviews the anatomy, pathophysiology, clinical presentation, diagnosis, and current treatment options of foraminal neuropathy.

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.207-209
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• 2007

We present an elderly patient with unilateral foraminal stenosis treated by isthmus resection. An 83-year-old female could not walk due to severe leg pain along right L5 sensory dermatome. Despite the laminotomy for spinal stenosis on the right side at the L4-5 level, her leg pain did not improve. Careful review of computed tomography scans and coronal source images of magnetic resonance myelography revealed foraminal stenosis on the right side at the L5 vertebra. Because of medical problem, she underwent isthmus resection on the right side at the L5 level instead of total facetectomy and fusion. After surgery, her leg pain was markedly improved. Isthmus resection showed successful result for this medically compromised elderly patient with unilateral foraminal stenosis.

• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.206-210
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• 2014

Objective : Lumbar spinal stenosis is a common degenerative spine disease that requires surgical intervention. Currently, there is interest in minimally invasive surgery and various technical modifications of decompressive lumbar laminectomy without fusion. The purpose of this study was to present the author's surgical technique and results for decompression of spinal stenosis. Methods : The author performed surgery in 57 patients with lumbar spinal stenosis between 2006 and 2010. Data were gathered retrospectively via outpatient interviews and telephone questionnaires. The operation used in this study was named central decompressive laminoplasty (CDL), which allows thorough decompression of the lumbar spinal canal and proximal two foraminal nerve roots by undercutting the lamina and facet joint. Kyphotic prone positioning on elevated curvature of the frame or occasional use of an interlaminar spreader enables sufficient interlaminar working space. Pain was measured with a visual analogue scale (VAS). Surgical outcome was analyzed with the Oswestry Disability Index (ODI). Data were analyzed preoperatively and six months postoperatively. Results : The interlaminar window provided by this technique allowed for unhindered access to the central canal, lateral recess, and upper/lower foraminal zone, with near-total sparing of the facet joint. The VAS scores and ODI were significantly improved at six-month follow-up compared to preoperative levels (p<0.001, respectively). Excellent pain relief (>75% of initial VAS score) of back/buttock and leg was observed in 75.0% and 76.2% of patients, respectively. Conclusion : CDL is easily applied, allows good field visualization and decompression, maintains stability by sparing ligament and bony structures, and shows excellent early surgical results.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.439-447
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• 2018

Background: Since open Wiltse approach allows limited visualization for foraminal stenosis leading to an incomplete decompression, we report the short-term clinical and radiological results of unilateral biportal endoscopic foraminal decompression using $0^{\circ}$ or $30^{\circ}$ endoscopy with better visualization. Methods: We examined 31 patients that underwent surgery for neurological symptoms due to lumbar foraminal stenosis which was refractory to 6 weeks of conservative treatment. All 31 patients underwent unilateral biportal endoscopic far-lateral decompression (UBEFLD). One portal was used for viewing purpose, and the other was for surgical instruments. Unilateral foraminotomy was performed under guidance of $0^{\circ}$ or $30^{\circ}$ endoscopy. Clinical outcomes were analyzed using the modified Macnab criteria, Oswestry disability index, and visual analogue scale. Plain radiographs obtained preoperatively and 1 year postoperatively were compared to analyze the intervertebral angle (IVA), dynamic IVA, percentage of slip, dynamic percentage of slip (gap between the percentage of slip on flexion and extension views), slip angle, disc height index (DHI), and foraminal height index (FHI). Results: The IVA significantly increased from $6.24^{\circ}{\pm}4.27^{\circ}$ to $6.96^{\circ}{\pm}3.58^{\circ}$ at 1 year postoperatively (p = 0.306). The dynamic IVA slightly decreased from $6.27^{\circ}{\pm}3.12^{\circ}$ to $6.04^{\circ}{\pm}2.41^{\circ}$, but the difference was not statistically significant (p = 0.375). The percentage of slip was $3.41%{\pm}5.24%$ preoperatively and $6.01%{\pm}1.43%$ at 1-year follow-up (p = 0.227), showing no significant difference. The preoperative dynamic percentage of slip was $2.90%{\pm}3.37%$; at 1 year postoperatively, it was $3.13%{\pm}4.11%$ (p = 0.720), showing no significant difference. The DHI changed from $34.78%{\pm}9.54%$ preoperatively to $35.05%{\pm}8.83%$ postoperatively, which was not statistically significant (p = 0.837). In addition, the FHI slightly decreased from $55.15%{\pm}9.45%$ preoperatively to $54.56%{\pm}9.86%$ postoperatively, but the results were not statistically significant (p = 0.705). Conclusions: UBEFLD using endoscopy showed a satisfactory clinical outcome after 1-year follow-up and did not induce postoperative segmental spinal instability. It could be a feasible alternative to conventional open decompression or fusion surgery for lumbar foraminal stenosis.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.508-512
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• 2018

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5-S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a $30^{\circ}$ arthroscope to enable foraminal decompression at the L5-S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5-S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a $30^{\circ}$ arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5-S1 level that preserves facet stability and provides symptomatic relief.

• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.377-381
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• 2007

Objective : The aim of this study was to evaluate the morphometric changes in neuroforamen in grade I isthmic spondylolisthesis by anterior lumbar interbody fusion [ALIF]. Methods : Fourteen patients with grade I isthmic spondylolisthesis who underwent single level ALIF with percutaneous pedicle screw fixation were enrolled. All patients underwent standing lateral radiography and magnetic resonance imaging [MRI] before surgery and at 1 week after surgery. For quantitative analysis, the foraminal height, width, epidural foraminal height, epidural foraminal width, and epidural foraminal area were evaluated at the mid-portion of 28 foramens using T2-weighted sagittal MRI. For qualitative analysis, degree of neural compression in mid-portion of 28 foramens was classified into 4 grades using T2-weighted sagittal MRI. Clinical outcomes were assessed using Visual Analogue Sale [VAS] scores for leg pain and Oswestry disability index before surgery and at 1 year after surgery. Results : The affected levels were L4-5 in 10 cases and L5-S1 in 4. The mean foraminal height was increased [p<0.001], and the mean foraminal width was decreased [p=0.014] significantly after surgery. The mean epidural foraminal height [p<0.001], epidural foraminal width [p<0.001], and epidural foraminal area [p<0.001] showed a significant increase after surgery. The mean grade for neural compression was decreased significantly after surgery [p<0.001]. VAS scores for leg pain [p=0.001] and Oswestry disability index [p=0.001] was decreased significantly at one year after surgery. Conclusion : Foraminal stenosis in grade I isthmic spondylolisthesis may effectively decompressed by ALIF with percutaneous pedicle screw fixation.