Width Of Intervertebral Foramen Research Articles

Radiographic characteristics-based classification system for percutaneous endoscopic lumbar discectomy surgical approach selection in patients with L5-S1 disc herniation: a hierarchical clustering analysis.

No classification system exists for aiding the selection of surgical approaches in L5-S1 disc herniation when undergoing percutaneous endoscopic lumbar discectomy (PELD). We aimed to identify radiographic subtypes to aid the selection of percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID) in patients with L5-S1 disc herniation via unsupervised hierarchical clustering analysis. In this retrospective case-control study, we gathered 296 anteroposterior and lateral lumbar spine radiographs (dataset 1) from Tianjin Hospital between January 2016 and October 2021 for clustering analyses. Additionally, we analyzed 111 patients who underwent PEID or PETD for L5-S1 disc herniation at Tianjin Hospital from January 2016 to August 2022. We included patients with radicular leg pain or back pain associated with intra-canal disc herniation who failed in conservative treatments over 6 weeks. First, pair-wise Spearman correlation coefficients were calculated among plain radiographic metrics in dataset 1 to reveal the association among these radiographic metrics. Second, hierarchical clustering analysis was conducted to unsupervised cluster the plain films into several subtypes. Last, for each radiographic subtype, the intraoperative blood loss (IBL), operation time (OT), total operating room time (TORT) along with visual analogue scale (VAS) and Oswestry Disability Index (ODI) were compared between patients underwent PETD or PEID with age as covariates. This study yielded 3 main findings: (I) iliac height (IH) was negatively correlated with intervertebral foramen width (IFW), intervertebral foramen height (IFH), and intertransverse height (ITH) (R=-0.50, -0.42, and -0.46, all P<0.001), ITH was positively correlated with IFW and IFH (R=0.40 and 0.53, all P<0.001); (II) 2 lumbosacral radiographic subtypes were identified via hierarchical clustering analysis; (III) relative to subtype 1, the patients identified as subtype 2 exhibited lesser IBL, shorter OT, and shorter TORT following PETD (t=2.92, P=0.006; t=2.65, P=0.012; t=3.17, P=0.003). The morphology pattern of the lumbosacral region affect the ease of different PELD procedures when performing percutaneous discectomy at the segment of L5-S1. Without considering the type of disc herniation, this classification system might aid spine surgeons in the selection of an appropriate surgical approach.

Analysis of risk factors for contralateral symptomatic foraminal stenosis after unilateral transforaminal lumbar interbody fusion.

To analyze the risk factors of contralateral symptomatic foraminal stenosis (FS) after unilateral transforaminal lumbar interbody fusion (TLIF) and to guide and standardize the operation process of unilateral TLIF to reduce the occurrence of contralateral symptomatic FS. A retrospective study was undertaken on 487 patients with lumbar degeneration who underwent unilateral TLIF in the Department of Spinal Surgery of Ningbo Sixth Hospital between January 2017 and January 2021, comprising 269 males and 218 females, with a mean age of 57.1years (range, 48-77years). Cases of intraoperative improper operations, such as screw deviation, postoperative hematoma, and contralateral disc herniation, were excluded, and cases of nerve root symptoms caused by contralateral FS were analyzed. Post-surgery, 23 patients with nerve root symptoms caused by contralateral FS were categorized as group A, and 60 patients without nerve root symptoms were randomly selected as group B during the same period. The general data (gender, age, body mass index (BMI), bone mineral density (BMD), and diagnosis) and imaging parameters before and after operation (including contralateral foramen area (CFA), lumbar lordosis angle (LL), segmental lordosis angle (SL), disc height (DH), foramen height (FH), foramen width (FW), fusion cage position, and the difference between postoperative and preoperative) were compared between the two groups. Univariate analysis was performed, and multivariate analysis was undertaken through logistics analysis to determine the independent risk factors. Additionally, the clinical outcomes of the two groups were compared immediately before surgery and one year after surgery, using the visual analogue scale (VAS) score and the Japanese Orthopaedic Association (JOA) score for evaluation. The patients in this study were followed up for a period of 19-25 (22.8atien months. Among them, 23 cases (4.72% incidence) were diagnosed with contralaterally symptomatic FS after the surgery. Univariate analysis indicated significant differences between the two groups in CFA, SL, FW, and cage coronal position. Logistic regression analysis identified preoperative contralateral foramen area (OR = 1.176, 95% CI (1.012, 1.367)), small segmental lordosis angle (OR = 2.225, 95% CI (1.124, 4.406)), small intervertebral foramen width (OR = 2.706, 95% CI (1.028, 7.118)), and cage coronal position not crossing the midline (OR = 1.567, 95% CI (1.142, 2.149)) as independent risk factors for contralateral symptomatic FS after unilateral TLIF. However, there was no statistically significant difference in the pain VAS score between the two groups one year after the operation. In contrast, there was a significant difference in the JOA score between the two groups. The identified risk factors for contralateral symptomatic FS after TLIF include preoperative contralateral intervertebral foramen stenosis, a small segmental lordosis angle, a small intervertebral foramen width, and the coronal position of the cage not crossing the midline. For patients with these risk factors, it is recommended to carefully lock the screw rod during the recovery of lumbar lordosis and ensure that the coronal position of the fusion cage is implanted beyond the midline. If necessary, preventive decompression should also be considered. However, this study did not quantify the imaging data for each risk factor, and further research is needed to improve our understanding of the topic.

Intervertebral Foramen Width Is an Important Factor in Deciding Additional Uncinate Process Resection in ACDF-a Retrospective Study.

Background: Anterior cervical discectomy and fusion (ACDF) has been established as a classic procedure for the management of cervical radiculopathy. However, it is unclear whether combined uncinate process resection (UPR) is necessary for treating cervical radiculopathy. Here, we investigated the clinical outcome of ACDF combined with UPR compared to ACDF alone to determine the necessity of UPR in treating cervical radiculopathy.Hypothesis: Uncinate process resection may be necessary in certain patients along with ACDF to achieve better clinical outcomes of cervical radiculopathy.Patients and Methods: Fifty-five patients underwent ACDF with UPR, and 126 patients without UPR were reviewed. The width and height of the intervertebral foramen were measured by 45° oblique X-rays. We also measured the Japanese Orthopedic Association (JOA) score and visual analog scale (VAS) score. C2–C7 Cobb angles were obtained from all patients pre- and post-operatively. Meanwhile, linear regression analysis was used to evaluate the relationship between the clinical outcomes and the intervertebral foramen width before surgery.Results: Linear regression analysis indicated that the improvement in the JOA and VAS scores was irrelevant to both the pre-operative width of the intervertebral foramen (wIVF) and the height of the intervertebral foramen (hIVF) in the ACDF+UPR group. However, pre-operative wIVF was associated with post-operative JOA and VAS scores in the ACDF alone group. Those with pre-operative wIVF <3 mm in the ACDF group had the least improvement in post-operative clinical symptoms due to the change in wIVF (P > 0.05). The ACDF group whose wIVF was over 3 mm showed similar clinical outcomes to the ACDF + UPR group, and wIVF significantly increased post-operatively (P < 0.05). The fusion rate and C2–C7 Cobb angles did not show significant differences between the two groups (P > 0.05).Discussion: Our current findings suggest that UPR should be considered when wIVF is <3 mm pre-operatively. However, there is no need to sacrifice the uncovertebral joint in ACDF when the pre-operative wIVF is over 3 mm.Level of Evidence: Level III.

Predictive Effect of Intervertebral Foramen Width on Pain Relief After ACDF for the Treatment of Cervical Radiculopathy.

Retrospective cohort study. To investigate the relationship between the preoperative width of the intervertebral foramen (WIVF) and the pain relief in patients who underwent anterior cervical discectomy and fusion (ACDF) for the treatment of cervical radiculopathy. Patients were divided into 2 groups based on pain relief status at the 6-month follow-up (pain relief group: 430 patients; persistent pain group: 108 patients). Possible factors such as age, sex, body mass index (BMI), the symptom duration, the preoperative Japanese Orthopedic Association (JOA) scores, the canal stenosis status, and the graft material were obtained. The C2-C7 Cobb angle, disc space, and width and height of the intervertebral foramen were measured on X-ray and CT 3-dimension reconstruction. Multivariate logistic regression was performed to identify the factors that affected pain relief. A receiver operating characteristic (ROC) curve was drawn for the predictive factors to determine the optimal threshold for foreseeing persistent pain. There were significant differences in the preoperative WIVF, symptom duration and ratio of disc space distraction between the 2 groups (each P < 0.05). The regression model showed that pain relief was negatively affected by the symptom duration and ratio of disc space distraction. Besides, an increase in the preoperative width of the intervertebral foramen (WIVF) could significantly decrease the possibility of persistent pain. Based on the ROC curve, the optimal threshold of preoperative WIVF was 4.35 mm. When the preoperative WIVF is equal to or less than 4.35 mm, the possibility of the occurrence of postoperative persistent pain significantly increased.

Evaluation of lumbar fusion using the anterior to psoas approach for the treatment of L5/S1 spondylolisthesis.

To date, no studies have evaluated the outcomes of lumbar interbody fusion using the anterior to psoas (ATP) approach in patients with spondylolisthesis at L5/S1. We; therefore, aimed to evaluate short-term surgical outcomes of interbody fusion using the ATP approach combined with posterior fixation in these patients.We performed a retrospective analysis of 9 patients with grade I spondylolisthesis at L5/S1 who were treated with fusion and posterior fixation using the ATP approach at our hospital from April to July 2018. The recorded parameters included operation time, intraoperative blood loss, complications, intervertebral fusion rate, radiological intervertebral height, intervertebral foramen height, intervertebral foramen width, pain, visual analog scale, and Oswestry disability index.Four men and 5 women at an average age of 57.8 years (range: 46–71 years) were enrolled in the study. The average operation time was 152.8 ± 22.9 minutes, and the average blood loss during surgery was 165 ± 27.5 mL. All patients confirmed the relief of their low back pain, and there were no serious complications. The follow-up time was more than 6 months. The visual analog scale and Oswestry disability index scores 3 days postoperatively and at the last follow-up were significantly lower than those before surgery (P < .05). At the last follow-up, the intervertebral space of the surgical segment showed bony fusion in all patients, and the intervertebral height and intervertebral foramen height and width were significantly increased compared with those before surgery (P < .05).The ATP approach was safe and effective for the treatment of spondylolisthesis at L5/S1. It showed low vascular injury and cage shift rates and was technically easy to perform. We recommended that surgeons identify the vessels in the surgical field preoperatively so that they can be secured or safely ligated during surgery.

Analysis of clinical efficacy of endo-LIF in the treatment of single-segment lumbar degenerative diseases

An innovative concept was proposed to treat the lumbar degenerative diseases with full-endoscopic translaminar lumbar interbody fusion (Endo-TLIF) and the efficacy was evaluated. A total of 44 patients from January 2017 to October 2018 were enrolled, including 20 patients undergoing full-endoscopic TLIF and 24 patients undergoing standard open TLIF. The Visual Analogue Scale (VAS) score, Oswestry Dability Index (ODI) and intervertebral fusion were observed in both groups at the last follow-up. The height and width of intervertebral foramen and height of intervertebral space were evaluated via imaging. Mean follow-up time for all patients 13.2 ± 3.2 months. The average operation time was 184.3 ± 70.6 min in experimental group and 191.1 ± 32.4 min in control group. The amount of bleeding was 38.5 ± 19.5 mL and 214.6 ± 61.6 mL. The VAS score was 4.9 ± 1.0 points in experimental group and 4.8 ± 1.0 points in control group before operation, and 0.8 ± 0.6 points and 0.8 ± 0.7 points at the last follow-up. The ODI was 83.5 ± 7.8% and 87.8 ± 5.9% before operation, and 9.9 ± 3.6% and 9.3 ± 3.7% at the last follow-up. The height and width of intervertebral foramen and height of intervertebral space in both groups were significantly improved (p < 0.05). The fusion rate at the last follow-up were 95% (19 cases) in experimental group and 92% (22 cases) in control group. Full-endoscopic TLIF is feasible in the treatment of single-segment lumbar degenerative diseases, which is characterized by small trauma, quick recovery and low cost. However, the large-sample long-term follow-up is needed to further evaluate its clinical efficacy and safety.

Necessity of routinely performing foraminoplasty during percutaneous endoscopic transforaminal discectomy in treating lumbar disc herniation

Objective To analyze the necessity of routinely performing foraminoplasty during percutaneous transforaminal endoscopic discectomy (PETD). Methods A total of 412 patients including 231 males and 181 females with an average age of 39.1±13 (20-80) years were enrolled in the present study. All patients were preoperatively diagnosed with single-segment lumbar disc herniation and underwent PETD by the same surgical group. The affected segments were at L3-4 in 32 cases, L4-5 in 289 cases, and L5S1 in 91 cases. Among them, 306 cases had no prolapse, 89 had mild up/down prolapse, and 17 had severe prolapse. MRI sagittal imaging was used to measure the height and width of the intervertebral foramen of L3, 4, L4, 5 and L5S1 segments, the distance between the lower edge of vertebral pedicle and the upper edge of the lower vertebral pedicle and the distance between the point 3 mm to the ventral side of the intervertebral space to the superior articular process. The necessity of performing foraminoplasty was evaluated by measuring the change of intervertebral foramen width using dynamic X-ray and verified during operation. Results The height of the intervertebral foramen of L3,4, L4,5 and L5S1 segments were 1.99±0.25, 1.89±0.15 and 1.52±0.26 cm, respectively. The width of the intervertebral foramen was 0.78±0.14, 0.75±0.13 and 0.64±0.13 cm, respectively. The distance between the lower edge of vertebral pedicle and the upper edge of the lower vertebral pedicle were 1.14±0.17, 1.05±0.16, and 0.98±0.19 cm, respectively. The distance between the point 3 mm to the ventral side of the intervertebral space to the superior articular process were 1.11±0.31, 1.17±0.20, and 0.95±0.14 cm, respectively. The width of the intervertebral foramen of the L3, 4 and L4,5 segments was significantly greater at the over-flexion position than at the over-extension position (P<0.05). Intraoperative verification showed that 347 cases (group A) did not need foraminoplasty. However, the other 65 patients (group B) needed foraminoplasty, including 31 at L4, 5 segment and 34 at L5S1 segment. One patient in group A and one in group B underwent revision operation due to residual intervertebral disc. At 2 years of follow-up, recurrence occurred in 4 patients in group A and 2 patients in group B. The ODI score and JOA score in group A and B were 18%±9%, 24.2±1.3 and 16%±7%, 23.9±1.3, respectively. There were not significantly different between patients in group A and B (t=1.70, P=0.090; t=1.71, P=0.088). The VAS score of lumbar pain of patients in group A was better than that of patients in group B (P<0.05). Conclusion Most of PETD of L3-S1 segments can reach the therapeutic target without performing foraminoplasty with half-half technique combined with far lateral access technique. Due to the special anatomical position of L5-S1 segment, the probability of performing foraminoplasty during operation is much higher. Performing foraminoplasty or not depends on the preoperative measurement of foramina and verification during the operation. Key words: Lumbar vertebrae; Intervertebral disc displacement; Diskectomy, percutaneous; Foraminotomy

CT assisted goat lumbar vertebrae anatomical measurement and comparison with human lumbar vertebrae

To study the anatomical measurement of goat lumbar vertebrae and to compare with human lumbar vertebrae, so as to build the foundation for establishing animal models of lumbar prosthesis. The anatomical parameters of the vertebral body, pedicle and intervertebral disc in the fresh lumbar vertebrae of Boer goat and the lumbar vertebrae of healthy adults were collected by computer aided software Mimics16.0, and the anatomical characteristics of the two lumbar vertebrae were compared with the statistical software. The anterior vertebral body height(VBHa) of goat lumbar was less than the middle vertebral body height(VBHm), which was less than the posterior vertebral body height(VBHp), and the maximum values were (38.7±2.9), (40.1±2.6) and (40.7±2.7) mm respectively. Its endplate width was greater than its depth, with the whole shaped like a heart or a kidney. The cranial endplate of goats was convex while the caudal endplate was depressed and the depression was small, with a maximum value of (1.6±0.6) mm. The pedicle height of goats increased from L₁1 to L̀ with the maximum of (30.5±1.9) mm; its pedicle width and angle increased firstly and then decreased with the increase of vertebra level and the minimum values were (6.7±0.4) mm and(45.9±2.6)° respectively. The anterior intervertebral disc height was larger than the middle which was larger than the posterior and all varied slightly with the changes of intervertebral spaces; the height and width of intervertebral foramen separately waved at (12.9±0.3) to (14.3±1.0) mm and (5.7±1.0) to (6.7±0.9) mm. The comparative results showed that the vertebral body height, pedicle height and angle of goats were greater than those of humans (P<0.05) while the width and depth of the endplate, the intervertebral disc height, and etc. were significantly smaller than those of humans (P<0.05). In addition, some structures, such as the height of pedicle and intervertebral disc, also showed different changing laws with the increase of vertebra level. Although there are similarities in goat lumbar spine in some aspects, such as endplate and foramen foramen, there are still many differences in many aspects. Understanding the anatomical characteristics of goat lumbar vertebrae and the difference between goat and human is of great guiding significance for the research of goat prosthesis and related technology.

The effect of the X-Stop implantation on intervertebral foramen, segmental spinal canal length and disc space in elderly patients with lumbar spinal stenosis

To evaluate the biomechanical effect of the X-Stop device on the intervertebral foramen (IVF) and segmental spinal canal length (SSCL), as well as the intervertebral disc space at the implanted and the adjacent segments in patients with lumbar spinal stenosis (LSS). Eight elderly patients with LSS, scheduled for X-stop implantation, were CT or MRI scanned to construct 3D vertebral models (L2-S1). Before and after the surgery, each patient was also imaged using a dual-fluoroscopic image system during weight-bearing standing and maximum extension-flexion. The positions of the vertebrae were then determined using an established 2D-3D model matching method. The data revealed that the postoperative IVF area was significantly increased by 32.9% (or 32 mm2) (p<0.05) and the IVF width was increased by 24.4% (or 1.1 mm, p=0.06) during extension, but with minimal change in standing and flexion. The IVF heights were significantly (p<0.05) increased at standing by 1.2 mm and extension by 1.8 mm, but not at flexion. The SSCL were significantly (p<0.05) increased at extension by 1.2 mm, but not at standing and flexion. Anterior disc space of the implanted level was significantly decreased from 8.0 to 6.6 mm during standing. The X-Stop implantation efficiently enlarged the IVF area in the elderly patients with LSS at the operated level with little biomechanical effect immediately on the superior and inferior adjacent levels. However, it reduced the anterior disc space at the implanted level.

Clinical perspectives on secular trends of intervertebral foramen diameters in an industrialized European society.

Low back pain origins have been a matter of great controversy. While spinal stenosis is now radiologically traceable, the alteration of intervertebral foramen is less clear. The aim of this study was to assess "secular trends"-alterations occurring from one generation to the next-in osseous intervertebral foramina of the major vertebral segments in an industrialized society, and to discuss their possible clinical implication. The macerated "maximum intervertebral foramen width" and "intervertebral foramen height" of all major vertebral levels in 71 non-pathologic Swiss adult skeletons from the nineteenth and early twentieth century, with known individual age and sex and similar geographic and socio-economic background, were measured by sliding caliper at validated landmarks. A secular trend of the increase in "maximum intervertebral foramen width" is found for most levels, with females showing a more prominent alteration. Additionally, the non-pathologic "maximum intervertebral foramen width" does not change with respect to individual age, nor is a significant side difference detectable. "Intervertebral foramen height," hereby defined as the difference of the dorsal vertebral body height minus pedicle height, demonstrates for most levels, and either sex, an insignificant negative secular trend. Neither stature nor skeletal robustness vary significantly through time within this particular sample. The results of this study, despite obvious inadequacies of methods used, exclude secular narrowing of the "maximum intervertebral foramen width" as the only cause of radiculopathy or spinal stenosis. Furthermore, we found a mild insignificant decrease of the clinically more relevant "intervertebral foramen height." Nevertheless, the detected short-time variability of the bony intervertebral foramen, independent of individual stature, skeletal robustness or age, argues for an enhanced focus on the understanding of clinically relevant changes of spinal morphology from generation to generation.