Changes in L4/5 Intervertebral Foramen Bony Morphology with Age

Exploring Pathways for Pain Relief in Treatment and Management of Lumbar Foraminal Stenosis: A Review of the Literature

BACKGROUND

Lumbar foraminal stenosis (LFS) involves the narrowing of neural foramina, leading to nerve compression, significant lower back pain and radiculopathy, particularly in the aging population. Management includes physical therapy, medications and potentially invasive surgeries such as foraminotomy. Advances in diagnostic and treatment strategies are essential due to LFS's complexity and prevalence, which underscores the importance of a multidisciplinary approach in optimizing patient outcomes.

METHOD

This literature review on LFS employed a systematic methodology to gather and synthesize recent scientific data. A comprehensive search was conducted across PubMed, Scopus and Cochrane Library databases using specific keywords related to LFS. The search, restricted to English language articles from 1 January 2000 to 31 December 2023, focused on peer-reviewed articles, clinical trials and reviews. Due to the heterogeneity among the studies, data were qualitatively synthesized into themes related to diagnosis, treatment and pathophysiology.

RESULTS

This literature review on LFS analyzed 972 articles initially identified, from which 540 remained after removing duplicates. Following a rigorous screening process, 20 peer-reviewed articles met the inclusion criteria and were reviewed. These studies primarily focused on evaluating the diagnostic accuracy, treatment efficacy and pathophysiological insights into LFS.

CONCLUSION

The comprehensive review underscores the necessity for precise diagnostic and management strategies for LFS, highlighting the role of a multidisciplinary approach and the utility of a unified classification system in enhancing patient outcomes in the face of this condition's increasing prevalence.

Anatomic Assessment of L1-S1 Neuroforaminal Dimensions Using Computed Tomography in 1,000 Patients: A Follow-Up Study

OBJECTIVES

While the radiographic criteria for diagnosing central lumbar stenosis are well described, criteria for diagnosing neuroforaminal stenosis (NFS) are unclear. Prior research has utilized magnetic resonance imaging (MRI) to characterize neuroforaminal dimensions (NFDs). However, this approach has inherent limitations that can adversely impact measurement accuracy. Existing literature on the use of computed tomography (CT) to investigate normal NFDs is limited. The purpose of the present study was to describe normal lumbar NFDs that would aid in the establishment of objective quantitative criteria for the diagnosis of NFS.

METHODS

This study evaluated CT imaging of 494 female and 506 male subjects between 18 and 35 years of age to determine normal NFDs, specifically the sagittal anteroposterior width, craniocaudal height, and area. Statistical analyses were performed to assess differences in NFDs according to variables including sex, height, weight, body mass index, and ethnicity.

RESULTS

Without differentiating between sides or disc levels, mean NFDs were 8.71 mm for sagittal anteroposterior width, 17.73 mm for craniocaudal height, and 133.26 mm2 for area (n = 10,000 measurements each). Male subjects had larger NFDs than females at multiple levels. Asian and Caucasian subjects had larger NFDs than Hispanic and African American subjects at multiple levels. There were no associations between NFDs and anthropometric factors.

CONCLUSIONS

The present study describes normal lumbar NFDs in young, healthy patients. NFDs were influenced by sex and ethnicity but not by anthropometric factors.

Anatomic Assessment of L1-S1 Neuroforaminal Dimensions Using Computed Tomography

BACKGROUND

Although the radiographic parameters for diagnosing central lumbar canal stenosis are well described, parameters for the diagnosis of neuroforaminal stenosis (NFS) are less well defined. Previous studies have used magnetic resonance imaging (MRI) and radiography to describe neuroforaminal dimensions (NFDs). Those methods, however, have limitations that may substantially distort measurements. Existing literature on the use of computed tomography (CT) to investigate normal NFDs is limited.

METHODS

This anatomic assessment evaluated CT imaging of 300 female and 300 male subjects between 18 and 35 years of age to determine normal NFDs, specifically the sagittal anteroposterior width, axial anteroposterior width, craniocaudal height, and area. Statistical analyses were performed to assess differences in NFDs according to variables including sex, age, height, weight, body mass index, and ethnicity.

RESULTS

Overall, mean NFDs were 9.08 mm for sagittal anteroposterior width, 8.93 mm for axial anteroposterior width, 17.46 mm for craniocaudal height, and 134.78 mm 2 for area (n = 6,000 measurements each). Male subjects had larger NFDs than females at multiple levels. Both Caucasian and Asian subjects had larger NFDs than African-American subjects at multiple levels. There were no associations between foraminal dimensions and anthropometric factors.

CONCLUSIONS

This study describes CT-based L1-S1 NFDs in young, healthy patients who presented with reasons other than back pain or pathology affecting the neuroforamen. Dimensions were influenced by sex and ethnicity but were not influenced by anthropometric factors.

LEVEL OF EVIDENCE

Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Specific foraminal changes originate from degenerative spondylolisthesis on computed tomographic images

PURPOSE

Operative treatment for degenerative spondylolisthesis (DS) is accompanied by the high incidence of nerve injury. Foraminal structures, especially the hypertrophied facet joints, have significant impacts on the adjacent nerve. This study aims to identify the specific foraminal changes relating to DS and nerve injury.

METHODS

The CT images of 70 patients with DS and 50 patients without lumbar disease were collected. The length and height of the foraminal structure were measured horizontally and vertically on sagittally reconstructed images. Horizontal stenosis, meaning to pending compression to nerve root after complete reduction, was evaluated on the image located to the middle of the foramen. Chi-square test or T-test were carried out using SPSS 26.0.

RESULTS

The hyperplasia of the superior articular process (SAP) and articular capsule (Ac) incidence rates in DS group was significantly more common than that of the control group (9.2 vs 0.0%, 42.9 vs 2.0%). The height and width of the SAP and Ac in vertical and horizontal directions were significantly greater than those in the control group (4.95 mm vs - 0.47 mm, P < 0.0001; 3.28 vs 0.02 mm, P < 0.0001; 5.27 vs3.44 mm, P < 0.0001; 2.60 vs 0.37 mm, P < 0.0001). In the DS group, hyperplasia of the SAP and Ac accounted for 9 and 43% respectively, 85 and 45% of which were accompanied by horizontal stenosis of the intervertebral foramen.

CONCLUSION

DS is usually characterized of excessive hyperplasia of the SAP and Ac, both of which are possible elements of nerve root injury after complete reduction in operation and should be focused on during surgery.

Efficacy of computed tomography in prediction of operability of L5/S1 foraminal stenosis using region of interest: A STROBE-compliant retrospective study

Symptoms of intervertebral foraminal stenosis are caused by compression of nerve root exiting the intervertebral foramen. Many attempts to measure the size of the neuromuscular exit have been made; however, only a few studies to compare the area differences between foramens by computed tomography (CT) were done. In this retrospective comparative study, we used the region of interest (ROI) in CT to measure and compare the area of intervertebral foramen between the healthy control group and the patient group.Eighty-one patients who underwent CT of the lumbar spine between May 2014 and December 2017 were enrolled. Using the medical imaging program, the foraminal area between L5 and S1 vertebrae was measured on the sagittal, coronal, and axial planes using ROI. Four groups were established for comparison: those diagnosed with foraminal stenosis by a radiologist and those who were not, those diagnosed with foraminal stenosis by orthopedic surgeons and those who were not. These groups were further divided into subcategories depending on whether the area was operated on for foraminal stenosis. Interobserver and intraobserver agreements were assessed.The mean age of patients was 56.5 years (range 17-84). The foraminal area of the surgical group on sagittal plane was significantly narrower than the control group (P = .005). However, the difference between the 2 groups on axial and coronal planes was not statistically significant (P > .1). Foraminal area <80 mm on sagittal images was a statistically significant risk factor for clinical symptom (P = .028) and that <65 mm was a statistically significant risk factor in predicting operability (P = .01). Interobserver and intraobserver agreements were fair to good on axial and coronal planes (about 0.7), whereas the agreements were excellent on sagittal plane (>0.9).In this study, we proved that measuring the intervertebral foraminal area using the ROI in CT in the lumbar spine is useful for diagnosing L5-S1 foraminal stenosis, especially on sagittal plane. Furthermore, not only does it provide aid in diagnosis, but it also helps predicting the operability of foraminal stenosis.