Foramen Area Research Articles

Maxillary expansion in customized finite element method models

The aims of this study were to develop a method for constructing a 3-dimensional finite-element model (FEM) of the maxilla and to evaluate the effects of transverse expansion on the status of various midpalatal sutures. A 3-dimensional FEM of the craniofacial complex was developed by using computed-tomography images and Bionix modeling software (version 3.0, CANTIBio, Suwon, Korea). To evaluate the differences between transverse expansion forces in the solid model (maxilla without a midpalatal suture), the fused model (maxilla with suture elements), and the patent model (maxilla without suture elements), transverse expansion forces of 100 g were applied bilaterally to the maxillary first premolars and the first molars. The fused model expressed a stress pattern similar to that of the solid model, except for the decreased first principal stress concentration in the incisive foramen area. The patent model, however, had a unique stress pattern, with the stress translated superiorly to the nasal area. The anterior nasal spine and the central incisors moved downward and backward in both solid and fused models but moved primarily downward with a slight backward movement of the anterior nasal spine in the patent model. Clinical observations of maxillary expansion can be explained by different suture statuses. This efficient and customized FEM model can be used to predict craniofacial responses to biomechanics in patients.

Stresses at the cranial base induced by rapid maxillary expansion.

An analysis of the distribution of stresses at the juvenile and adult cranial base after implementation of a rapid palatal suture expansion was the goal of this study. Of particular interest were stresses occurring near the cranial foramina containing vulnerable structures. The stresses were simulated and analyzed using a finite elements model of the human cranial base. The model consisted of several skull bones (sphenoid, frontal bone, occipital bone, and the two temporal bones) with a total of 41,556 finite elements. To illustrate the differences between reactions in the juvenile and the adult, the differing bone elasticity was depicted as variations in the modulus of elasticity. At the juvenile cranial base only moderate stresses occurred during rapid palatal suture expansion, apparently precluding the likelihood of any serious complications in the area of the foramina. The situation in the adult, however, was different. Because of the reduced elasticity of the bony structures, considerable stress already occurred on light bending of the pterygoid process, especially in the area of the round foramen, the oval foramen, and the superior orbital fissure, all of which might lead to microfractures with injury of nervous and vascular structures. The lower the bone elasticity on carrying out a rapid palatal suture expansion, the more important safety measures are for protecting the cranial base. For this reason the pterygomaxillary connection should be severed on both sides in adults when carrying out a surgically assisted palatal suture expansion.

The Influence of Cervical Traction, Compression, and Spurling Test on Cervical Intervertebral Foramen Size

A comparative measurement design investigating the C4-Th1 intervertebral foramen under simulated clinical tests for cervical radiculopathy using magnetic resonance imaging. The purpose of this study was to evaluate functional changes in the cervical intervertebral foramen during the axial compression test (ACT), axial distraction test (DT), and Spurling test (SST). Although alterations of the cross-sectional area of the cervical intervertebral foramen during flexion/extension and rotation have been reported, there are no studies that have measured functional changes in foramen cross-sectional area (FCSA) or shape during the simulation of clinical tests for cervical radiculopathy. 23 participants (12 men, age: 24.52 years) without history of significant spinal disorders were studied. The 3-dimensional sequence of the magnetic resonance imaging of the foramen was performed with a 0.2-T horizontally open unit. Measurements were taken of FCSA and foramen shape (ratio of foramen height to FCSA). These measurements were conducted under 4 different conditions; control-resting in supine, DT-neck in neutral with a 12 kg distraction force, ACT-neck in neutral with a 7 kg axial compression force, SST-the cervical spine was extended (12.79 degrees ), rotated (63.36 degrees ), and laterally flexed (28.49 degrees ), in a standardized manner. At all levels except for C7-Th1, the FCSA significantly increased (P < 0.05) during the DT to around 120% of control. In contrast, FCSA significantly decreased to approximately 70% of control (P < 0.05) at all levels during the SST. In addition, there were significant differences (P > 0.05) in foramen shape between the ACT and SST condition, but only at the C4-C5 and C5-C6 levels. During 3 clinical tests for cervical radiculopathy functional, relevant, and changes in the cervical intervertebral foramen were evident particularly in the middle cervical spine.

Morphological changes in the cervical intervertebral foramen dimensions with unilateral facet joint dislocation

Background Many investigators have conducted studies to determine the biomechanics, causes, complications and treatment of unilateral facet joint dislocation in the cervical spine. However, there is no quantitative data available on morphological changes in the intervertebral foramen of the cervical spine following unilateral facet joint dislocation. These data are important to understand the cause of neurological compromise following unilateral facet joint dislocation. Methods Eight embalmed human cadaver cervical spine specimens ranging from level C1-T1 were used. The nerve roots of these specimens at C5-C6 level were marked by wrapping a 0.12 mm diameter wire around them. Unilateral facet dislocation at C5-C6 level was simulated by serially sectioning the corresponding ligamentous structures. A CT scan of the specimens was obtained before and after the dislocation was simulated. A sagittal plane through the centre of the pedicle and facet joint was constructed and used for measurement. The height and area of the intervertebral foramen, the facet joint space, nerve root diameter and area, and vertebral alignment both before and after dislocation were evaluated. Results The intervertebral foramen area changed from 50.72 ± 0.88 mm 2 to 67.82 ± 4.77 mm 2 on the non-dislocated side and from 41.39 ± 1.11 mm 2 to 113.77 ± 5.65 mm 2 on the dislocated side. The foraminal heights changed from 9.02 ± 0.30 mm to 10.52 ± 0.50 mm on the non-dislocated side and 10.43 ± 0.50 mm to 17.04 ± 0.96 mm on the dislocated side. The facet space area in the sagittal plane changed from 6.80 ± 0.80 mm 2 to 40.02 ± 1.40 mm 2 on the non-dislocated side. The C-5 anterior displacement showed a great change from 0 mm to 5.40 ± 0.24 mm on the non-dislocated side and from 0 mm to 3.42 ± 0.20 mm on the dislocated side. Neither of the nerve roots on either side showed a significant change in size. Conclusions The lack of change in nerve root area indicates that the associated nerve injury with unilateral facet joint dislocation is probably due to distraction rather than due to direct nerve root compression.

Radiological and clinical outcomes of posterolateral fusion versus posterior lumbar interbody fusion for spondylolisthesis

Objective To compare two different kinds of operation: instrumented posterolateral lumbar fusion (PLF) and instrumented posterior lumbar interbody fusion (PLIF) in the treatment of low grade spondylolisthesis. Methods We retrospectively analyzed patients who received these two kinds of operation for low grade spondylolisthesis between June 2004 and December 2006, including PLF in 53 and PLIF in 60. Disc height, Boxall index, segment angle and area of intervertebral foramen were compared both before and after the operation and during the follow-ups as radiological measurement. The Oswestry disability index(OPI) and visual analogue scale (VAS) were measured to compare low back pain, leg pain, and disability. Anatomical reduction rate and fusion rate were also calculated. The radiological measurements and the clinical indexes were compared at the last follow-up. Results The average operation time and blood loss was: PLIF, (194.3±54.7) min, (402.2±123.9) ml; PLF, (179.3±45.7) min, (367.2±102.3) mi, which were of no statistical significance. PLIF group turned up better results in all the post operation radiological measurements, which was statistically significant. The fusion rate was 96.7% and 86.8% respectively, which was not statistically different. The VAS for both lumbar and leg pain as well as the ODI were improved either post operation or in the one year follow-up. The excellent rate for subjective evaluation was 56.7% in PLIF group and 37.7% in PLF group. Conclusion Instrumented PLIF is an effective treatment for low grade spondylolisthesis. It has yield superiority over PLF in correction of spondylolisthesis, maintenance of disc height, regaining of lumbar lordosis and enlargement of intervertebral foramen area, and contributes to a higher rate of excellent results. Key words: Spondylolisthesis; Lumbar vertebrae; Spinal fusion

Primary and secondary dentine thickness at the apical foramen of the mesial and distal root of the lower first permanent molar

Introduction Knowledge of the complexity of the root canal system in lower first molars and particularly the apical part of the root affects significantly the realization and success of the endodontic procedure. Aim The aim of this paper was to determine the thickness of the primary and secondary dentine around the main foramen of the mesial and distal root of the lower first permanent molar in teeth of various ages. Material and Method Fifty extracted lower first molars of both male and female patients extracted for various reasons were used in the study. All teeth were allocated to three age groups: under 25 years old (15 teeth), between 26 and 50 (20 teeth) and over 51 years old (15 teeth). After access cavity preparation, canal orifices were enlarged and root canals were explored using hand K-files #10. Using a diamond disc, the root tip was then cut off in the area of the apical foramen. Dentine thickness was determined using a complex configuration comprising of several devices which were interconnected by software. These included a polarised microscope (Leica DMLSP), a digital camera (Leica DC300) and a scanner. Results The results showed that the greatest mean thickness of the primary dentine was in the mesial root of the first lower molar in the first age group (0.177 mm), followed by the third (0.145 mm) whilst the least mean thickness was observed in the second age group (0.141 mm). In the distal root, the mean thickness of the primary dentine was in the second (0.175 mm), then the first (0.138 mm) and finally the third group (0.100 mm). The mean thickness of the secondary dentine in the mesial root was observed in the second group (1.25 mm), followed by the third (1.11 mm) whilst the least mean thickness was found in the first age group (0.95 mm). The mean thickness of the secondary dentine in the distal root was observed in the second group (1.26 mm), then the third (1.18 mm) whilst the least mean thickness was found in the first age group (0.99 mm). Conclusion The obtained results suggested that the mean thickness of the primary dentine in the mesial and distal roots was comparable. For both mesial and distal roots, the greatest mean thickness of the secondary dentine was observed in the second age group.

Middle turbinate angiofibroma in an elderly woman

Angiofibromas are histologically benign vascular tumors, originating from the nasopharynx, near by the area of sphenopalatine foramen. These neoplasms occur typically in male adolescents. Reports of primary extranasopharyngeal angiofibromas have appeared sporadically in the literature in English. We present the first case of an elderly woman with tumor arising from the middle turbinate, diagnosed as angiofibroma. A 63-year-old female presented with left-sided nasal obstruction and epistaxis. Endoscopic evaluation revealed a polypoid mass arising from the anteroinferior portion of the left middle turbinate. Computed tomography (CT) scan showed a soft-tissue opacity that filled the anterior part of the left nasal cavity. After the endoscopic excision of the mass, postoperative pathohistological and immunohistochemical analysis confirmed the diagnosis of an angiofibroma. Two years later, the patient was free of symptoms and without endoscopic evidence of recurrence. Extranasopharyngeal angiofibromas arising from the nasal cavity are extremely rare tumors. Immunohistochemical analysis is very important in all doubtful cases, especially in those with atypical location.

Chordomas Involving Multiple Neuraxial Bones

We present a patient with multifocal symptomatic osseous chordomas having unusual growth patterns with review of the pertinent literature. The patient was 62-year-old male and had multiple osseous chordomas located in sacral, thoracic, and paraclival jugular foramen areas. There was no metastasis in other organs. All affected sites were osseous. The multicentric chordomas are extremely rare. This case could be considered as a chordoma involving multiple neuraxial bones. But, the possibility of multicentricity could also be thought. In such cases radical resection should be performed for each lesion at the initial diagnosis. If complete surgical resections are infeasible or impossible, preoperative or postoperative radiation therapy should be planned for the highest possibility of successful treatment.

Characteristics of Accessory Mental Foramina Observed on Limited Cone-beam Computed Tomography Images

In this retrospective study with limited cone-beam computed tomography (limited CBCT), we investigated the anatomic characteristics of the accessory mental foramina and accessory branches of the mandibular canal. The CBCT records of approximately 150 patients were evaluated, and 17 accessory mental foramina were found in 16 patients. The anatomic peculiarities of the mandibular canal that might be relevant to endodontic treatment were observed. Accessory mental foramina tended to exist in the apical area of the first molar and posterior or inferior area of the mental foramen. The accessory branches of the mandibular canal showed common characteristics in the course of gently sloping posterosuperior direction in the buccal surface area. Verification of the existence of accessory mental foramina would prevent accessory nerve injury during periapical surgery. In root canal treatment, the possibility of accessory mental foramina–related nerve paresthesia seems low unless the mental foramen and mandibular canal are injured. Limited CBCT is effective for presurgical 3-dimensional assessment of the neurovascular structures in dentoalveolar treatment.

Comparison of outcomes for posterior lumbar interbody fusion (PLIF) between spinal block bullet and fusion cages

Background: Spinal block bullet cages are considered interbody spacers rather than providing a scaffold, into which osteoinductive or osteoconductive materials could be placed. On the other hand, hollow fusion cages provide interbody fusion through osteoinductive or osteoconductive materials placed inside them. While posterior lumbar interbody fusion (PLIF) with spinal block bullet cages is thought to achieve less fusion than that with fusion cages, there are no reports of previous investigation. We compared the PLIF outcomes between the two different cages. Methods: A series of patients (n=25) with lumbar disc diseases or degenerative lumbar spondylolisthesis were retrospectively reviewed; Group 1 (n=11) underwent PLIF with bullet cages and Group 2 (n=14) with fusion cages at a single level. Both groups received internal fixation with transpedicular screws and rods at the same level. Rostral adjacent level mobility, segmental motion, ratio of disc height, and foramen area in the fusion level were studied on the follow-up X-ray images. Fusion success was defined as segmental stability and absence of radiolucency at the cage-end plate interface. Visual analogue pain score (VAS) and the SF-8(superscript TM) health survey (SF-8) were used to access the clinical outcome. Results: The duration of follow-up was 25.9±10.65 months in Group 1 and 19.57±13.22 months (p=0.22) in Group 2. Group 1 subjects achieved the same results as those in Group 2 in segmental motion (Groups 1, 2=1.40±0.71°, 1.81±0.94°; p=0.28), ratio of disc height (Groups 1, 2=0.3±0.03, 0.29±0.07; p=0.89), foramen area (Groups 1, 2=1.30±0.28cm^2, 1.18±0.33cm^2; p=0.36), and rostral segmental motion (Groups 1, 2=6.43±4.08°, 8.89±4.84°; p=0.201). Moreover, there was no statistical difference between both groups in VAS (Group 1, 2=2.72±1.13, 3.1±0.96; p=0.44) and SF-8 (Group 1, 2=16.54±2.93, 15.1±2.37; p=0.19). Conclusion: According to our study, the spinal block bullet cages achieved the same radiological parameters and clinical outcomes for PLIF as the fusion cages.

Variants in the structure and topography of the superior margin of the epidural space of the human spinal cord

Variants in the structure of the upper margin of the epidural space at sites of transition from the dura mater of the spinal cord to the dura mater of the brain were studied. Stereoepidurographic (88 observations) and corrosion studies (49 observations) identified four levels for the position of the upper margin of the anterior section (intracranially located, lower edge of the occipital bone, bodies of C1 and C2) along with five levels for the posterior section (occipital bone, occipital bone-arch of C1, C1, C1-C2, C2) of the epidural space. Variants on the shape of the upper margin of the anterior (falciform, oval, and dentate in the frontal plane; pointed, flexed spurs, pointed slits, and olive-shaped in the sagittal plane) and posterior (collar-shaped, oval, and bidentate forks with prongs of equal length and forks with prongs of unequal lengths) sections of the epidural space arose as a result of asymmetry in the attachment of the upper sections of the sac of the dura mater of the spinal cord to the walls of the vertebral canal. Weak areas of the upper wall of the epidural space (sites of transition from the dura mater of the spinal cord to the dura mater of the brain, paravasal capsule of the vertebral artery, the area of the first intervertebral foramen) were seen.

Endoscopic resection of cavernoma of foramen of Monro in a patient with familial multiple cavernomatosis

Intraventricular cavernomas are extremely unfrequent and only 11 cases of cavernous hemangioma to occur at the foramen of Monro have been reported in the literature. This 56 years old patient was admitted with progressive and intractable headache of 10 days of evolution. He was known to suffer familial multiple cavernomatosis. Magnetic resonance imaging (MRI), revealed obstructive hydrocephalus due to a cavernoma located in the area of the left foramen of Monro. Under neuronavigation guidance, complete endoscopic resection of the cavernoma was performed and normal ventricular size achieved. The patient experienced transient recent memory loss that resolved within a month after surgery. In the literature attempted endoscopic resection is reported to be abandoned due to bleeding and ineffectiveness of piecemeal endoscopic resection. In this case, the multiplicity of the lesions made it advisable to resect the lesion endoscopically, to avoid an open procedure in a patient with multiple potentially surgical lesions. Endoscopic resection was uneventful with easy control of bleeding with irrigation, suction, and bipolar coagulation despite dense vascular appearance of the lesion. During the procedure, precise visualization of the vascular structures around the foramen of Monro allowed complete resection with satisfactory control of the instruments. To the best of the authors’ knowledge, this is the first published cavernoma of foramen of Monro successfully resected using an endoscopic approach.

Vascular foramina of the metacarpophalangeal sesamoid bones of Greyhounds and their relationship to sesamoid disease

To apply a novel technique and use the number and size (diameter and mean area) of vascular foramina to estimate potential blood supply in the metacarpophalangeal bones of dogs. 28 Greyhounds. The forelimb sesamoid bones of 23 dogs were obtained after dogs were euthanized. Bones were isolated and examined by scanning electron microscopy. The number, diameter, and area of vascular foramina were determined by image analysis. Arterial distribution was assessed by use of resin injection in the sesamoid bones of 5 additional dogs. Sesamoids 2 and 7 had significantly fewer foramina (mean +/- SE, 38.9+/-2.5) and lower total foramen area (0.55+/-0.04 mm(2)), compared with values for other sesamoids (70.4+/-3.3 foramina and 1.43+/-0.06 mm(2), respectively). Mean area and diameter of foramina of sesamoids 2 and 7 were also smaller in some regions. Comparison of the foramen distribution in dogs with sesamoid disease and clinically normal dogs revealed that for sesamoids 2 and 7, intact sesamoids from dogs with sesamoid disease had a significantly lower total foramen area (20 sesamoids from 9 dogs, 0.45+/-0.04 mm(2)), compared with sesamoids in clinically normal dogs (59 sesamoids from 14 dogs, 0.58+/-0.03 mm(2)). However, for sesamoids other than 2 and 7, dogs with sesamoid disease had a significantly greater foramen area. The restriction of vascular foramina in sesamoids 2 and 7 appeared to mirror the disease distribution and disease risk for specific dogs.

Variation of the obturator foramen and pubic arch of the female bony pelvis

The purpose of this study was to determine dimensions of the obturator foramen and pubic arch of the female pelvis and to assess for variability. Ninety-six female pelvises were selected from the Cleveland Natural History Museum. The obturator foramen area, pubic arch angle, pubic ramus, pubic symphysis, and anterior urogenital triangle area were measured. Linear regression was used to evaluate independent associations. There was considerable variability of the bony architecture. The mean obturator foramen area was 12.2 +/- 2.1 cm(2) (range, 7.38-18.22 cm(2)). After controlling for height, the pubic ramus width, pubic symphysis length, and interobturator foramina distance were significantly greater in European American women compared with African American women. Obturator foramen area increased with increasing height (P = .0008) but was not associated with race. There is considerable variability in the bony architecture of the obturator foramen and pubic arch of the female pelvis. Race and height may account for some of these variabilities.

Lumbar Nerve Root Occupancy in the Foramen in Achondroplasia

Lumbar stenosis is common in patients with achondroplasia because of narrowing of the neural canal. However, it is unclear what causes stenosis, narrowing of the central canal or foramina. We performed a morphometric analysis of the lumbar nerve roots and intervertebral foramen in 17 patients (170 nerve roots and foramina) with achondroplasia (eight symptomatic, nine asymptomatic) and compared the data with that from 20 (200 nerve roots and foramina) asymptomatic patients without achondroplasia presenting with low back pain without neurologic symptoms. The measurements were made on left and right parasagittal MRI scans of the lumbar spine. The foramen area and root area were reduced at all levels from L1 to L5 between the patients with achondroplasia (Groups I and II) and the nonachondroplasia group (Group III). The percentage of nerve root occupancy in the foramen between Group I and Group II as compared with the patients without achondroplasia was similar or lower. This implied the lumbar nerve root size in patients with achondroplasia was smaller than that of the normal population and thus there is no effective nerve root compression. Symptoms of lumbar stenosis in achondroplasia may be arising from the central canal secondary to degenerative disc disease rather than a true foraminal stenosis. Level I, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Quantitative Evaluation of the Location of the Vertebral Artery in Relation to the Transverse Foramen in the Lower Cervical Spine

This study assessed the relationship of the vertebral artery and the transverse foramens in the lower cervical spine by computer tomographic angiography (CTA) measurements. To study the location and the size of the vertebral artery in relation to the transverse foramens in the lower cervical spine. Although many transverse foramen violations had been reported during pedicle screw insertion, the vertebral artery injury seems not as much as expected. The location and size of the vertebral artery in relation to the transverse foramen in the lower cervical spine is not very clear until now. Fifty patients were selected in our study group. Several parameters were measured on the CTA axial imagines of C3-C7, including the maximal width (W) and the maximal height (H) of transverse foramen, the diameter of vertebral artery (AL), the shortest distance between the vertebral artery and the border of transverse foramen medial (M), lateral (L), anterior (A) and posterior (P), the shortest distance between the vertebral artery and pedicle (h), the area of vertebral artery (AVA) and transverse foramen (AF), and the ratio between AVA and AF (AVA/AF). W, H, and AF increase from C3-C6. M is shorter than L at all measurements. A is shorter than P at C3, C4, and C5, a little bit longer than P at C6 on the contrary. The shortest distance between vertebral artery and pedicle (h) vary from C3-C7, the shortest 0.5 +/- 0.2 mm at C3, the longest 7.3 +/- 2.7 mm at C7. AVA/AF decrease from C3-C6, 35.7 +/- 15.7% at C3 and 27.4 +/- 12.8% at C6. Vertebral artery is in the medial part of transverse foramen. There is a relative "abundance space" for vertebral artery in transverse foramen.

Quantitative Method to Evaluate the Functionality of the Trigeminal Nerve

The primary objective of this study was to yield normal range values, with a current perception threshold technique, that could be used to assess the functionality of the third division of the trigeminal nerve on a healthy population. Moreover, we wanted to evaluate the impact of gender and training on these values. Standardized current perception threshold (CPT) measures using constant alternating current sinusoid waveform stimulus at 5, 250, and 2,000 HZ were obtained from 50 healthy patients at the mental foramen area bilaterally using a Neurometer current perception threshold device (Neurotron Inc, Baltimore, MD) (2,000 Hz specifically stimulates Abeta fibers, 250 Hz Adelta fibers, and 5 Hz stimulates C fibers). The mean CPT values for the 2,000, 250, and 5 Hz groups were respectively, 157.6 +/- 54.67, 53.10 +/- 27.64, and 33.44 +/- 23.17 mAmp. These values were used to construct a CPT scale to classify patients in the hyperesthetic, normative, or hypoesthetic range. There were no significant differences when comparing CPT values in men and women except in the 2,000 Hz group (P < .02; n = 23). In addition, the test was carried out a first time on the right side and a second time on the left. This training procedure showed a significant decrease in the CPT values in men at 2,000 Hz (P < .01; n = 23) for the second measure. The Neurometer can be beneficial for the evaluation and intraneural localization of sensory dysfunctions associated with the third division of the trigeminal nerve. It also could be used for initial diagnosis and subsequent evaluation of the patient's neurologic status through the course of their condition.

Poster 211: Utility of the Mandibular Channel Retractor With Wings for Mandibular Sagittal Split Ramus Osteotomy

Poster 211: Utility of the Mandibular Channel Retractor With Wings for Mandibular Sagittal Split Ramus Osteotomy

Quantitative changes in the cervical neural foramen resulting from axial traction: in vivo imaging study

Background context Cervical traction has a long history as a method of conservative treatment for cervical spine diseases. However, information on quantitative changes in the cervical neural foramen resulting from axial traction in vivo is lacking. Purpose To quantitatively evaluate the changes in the neural foramen of the cervical spine during axial traction in vivo. Study design A prospective radiographic analysis of the cervical neural foramen of adult volunteers. Patient sample Fifteen healthy volunteers (10 men, 5 women) without any history of cervical spine disease. Outcome measures The changes in cervical cross-sectional foraminal areas and heights were measured. Methods Cervical magnetic resonance (MR) images of the volunteers were taken at the neutral position and were reconstructed in the oblique plane perpendicular to the long axis of each neural foramen from the C2–3 to the C6–7 level. The changes in the neural foraminal dimensions at incremental axial traction forces (0, 5, 10, and 15 kg) were analyzed. Results After each 5-kg incremental increase in traction weight, there was a significant (p value less than .05) increase in area and height of the intervertebral foramen compared with the position in which no weight was applied. There was an average increase of 5.81%, 16.56%, and 18.9% in the foraminal area and an average increase of 3.75%, 8.67%, and 10.43% in foraminal height compared with the position with no weight at traction of 5, 10, and 15 kg, respectively. There was no statistically significant difference for the increase in foraminal area and height from 10 to 15 kg of traction (p value greater than .05). Conclusions There was a significant increase in intervertebral foraminal area and height after each 5-kg increment in traction weight compared with the position in which no weight was applied. From 10 to 15 kg of traction, there was no significant change in the foraminal area and height.

The Changes in the Dimensions of Neural Foramen After Anterior Interbody Fusion in the Spondylolisthesis

Study Design: A prospective radiological assessment was performed using computerized tomography measurements. Objectives: The aim of this study was to assess the changes in the dimensions of the neural foramen after anterior interbody fusion with posterior fixation in spondylolisthesis. Summary of Literature Review: Anterior lumbar interbody fusion distracts the height and width of the neural foramen. Materials and Methods: Anterior interboody fusion with posterior fixation was performed in twenty-five patients. The sagittal parameters were the height and area of the neural foramen. The fused lumbar segments was imaged in the direct sagittal projections in a CT (SOMATOM Senstaion; SIMENS, Germany) and 1-mm slice thickness before surgery and after solid fusion. Computer digitation was used for the measurements independently by three different observers. Statistical analysis was performed using a Wilcoxon signed test and a paired T-test to determine the correlation between the measurements, and Pearson correlation to determine the level of interobserver and intraobserver agreement. Results: After anterior interbody fusion and posterior fixation, the height and the area of the neural foramen had increased significantly by 15.5±14.0%(p�0.001) and 23.2±17.7%(p�0.001). There was a significant confidence in interobserver (0.9466~0.9996) and intraobserver(0.8896~0.9991) agreement. Conclusions: Anterior interbody fusion significantly increased the changes in the dimensions of the neural foramen. Anterior distraction and decompression with anterior interbody fusion increased the area of the neural foramen This study shows that anterior interbody fusion can be used to decompress the neural foramen in the spondylolisthesis.