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43 (); 17-24
doi:
10.1016/j.jor.2023.07.022

Analysing lumbar pedicle morphometry observed via traditional and recent modalities

, , ,
a Department of Anatomy, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India
b Department of Anatomy, ESIC Medical College & Hospital, Bihta, Patna, Bihar, India
c Department of Anatomy, All India Institute of Medical Science, Patna, Bihar, India
d Department of Radiodiagnosis, All India Institute of Medical Science, Deoghar, Jharkhand, India

∗Corresponding author: Ravi Kant Narayan. narayanintouch@gmail.com

Received: , Accepted: ,
Professor P K Surendran Memorial Education Foundation
Disclaimer:
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.

Abstract

Abstract

The present study was conducted to collect morphometric data on the lumbar vertebrae pedicles of the adult population from the eastern parts of India and analyse the variations, if any, with other parts of the country and the world.

The retrospective cross-sectional study where lumbar pedicle morphometric data was obtained via dried bone, the 3D Lumbar vertebrae images were obtained by scanning the dried lumbar vertebrae, and the 3D lumbar vertebrae model was generated from a 1 mm thin CT scan slice of the Lumbar spine of patients who were advised to have a CT scan of the abdomen for reasons other than related to the vertebral column. Both linear and angular measurements in the lumbar pedicles were made bilaterally.

The transverse pedicle width is widest at L3 and the narrowest at L2 vertebra bilaterally. The sagittal pedicle width at L4 vertebrae was observed to be the widest bilaterally, while L3 had the narrowest pedicle. The pedicular and body length along the pedicular axis is longer than the central axis at all the lumbar levels. The linear measurement along the pedicular axis was longest at L5 bilaterally via both modes, with a range of 18.2–47.31 mm for bones and 21.03–49.28 mm for CT scan morphometry. The transverse pedicular angle on analysis was observed to increase as one goes down the spine from L1 to L5, with a steep rise between L4 and L5. In contrast, the sagittal pedicular angle decreased as we went caudally toward the L5 vertebrae.

The present study data had significant differences among the values reported in the literature from the different populations for the parameters studied. The data obtained by this study will be highly beneficial for the success of the free-hand technique of pedicle screw insertion.

Keywords

Lumbar vertebrae
Pedicle
Transverse pedicle width
Sagittal pedicle width
Transverse pedicle angle
Sagittal pedicle angle
1

1 Introduction

In the present-day scenario, the transpedicular approach is preferably used in spinal fixation of disorders such as fractures, spondylolisthesis, spinal instability, tumours, etc. The pedicle has a long bone-like structure, and the cortex is responsible for the intense pull-out strength of the pedicle.1–4 On account of this, the posterior approach of spine fixation is used as the standard treatment method for spinal deformity.5–7 Furthermore, transpedicular fixation is a multi-level segment fixation, providing a biomechanical advantage over conventional methods.6–8

Pedicle has four anatomical quadrants based on the 3D distribution of CT attenuation (i.e., mean Hounsfield unit, HU). The mean HU of the medial quadrant is more than the lateral, and that of the Caudal is more than the Cranial quadrant. Therefore, the lumbar vertebra is more prone to lateral and cranial breach.1 Due to this complicated internal structure of the pedicle, the pre-operative determination of specific pedicle morphometry and its variations would help plan exact screw fixation without breach.6

Since there are two basic techniques of pedicle screw insertion: freehand technique and assisted technique (either fluoroscopy),9 where the latter pertains to very high radiation exposure and increases the chance of surgical site infection, these tribulations depend on the surgeon's experience and knowledge of the pedicle to adjacent bony landmarks, making the free-hand technique of screw insertion the safest.10,11

The success of the free hand technique depends on pre-determined data on the pedicle.12–14 The literature reports data on the Lumbar pedicle via different modes (traditional modes such as bone morphometry and radiological studies comprising of radiographs and CT) from across the globe. Many reports have presented significant variations between the populations, which accounts for clinical implications concerning internal fixation.6,7,13,15–29 This draws attention to the fact that pedicle morphometric data from parts of India, which are meagrely reported in the literature, needs to be studied, analysed and compared among the modalities, and with the reports from other parts of the country and the World. The present study was conducted to collect data on the Lumbar pedicles of the adult population from the eastern parts of India and analyse the differences, if any.

2

2 Material and methods

The retrospective cross-sectional study of pedicle morphometric data was performed in different institutes in the eastern part of the country. The morphometric data of the lumbar pedicles were obtained via three modalities.i.From dried Lumbar vertebrae extracted from cadavers (Fig. 1

a, shows transverse pedicle angle; b, sagittal pedicle angle; c, PBLca – Pedicle and body length along the central axis PBLpa - Pedicle and body length along the pedicular axis TPW – Transverse pedicular width; d, SPW – Sagittal pedicular width.
Fig. 1 a, shows transverse pedicle angle; b, sagittal pedicle angle; c, PBLca – Pedicle and body length along the central axis PBLpa - Pedicle and body length along the pedicular axis TPW – Transverse pedicular width; d, SPW – Sagittal pedicular width.
a),ii.From Geoform - the 3D Lumbar vertebrae images were obtained by scanning (via Artec Space Spider portable 3D scanner with an accuracy of 0.05 mm and 0.1 mm resolution) the dried lumbar vertebrae (Fig. 2
a, scanning of the dried lumbar vertebrae to generate a Geoform for morphometric measurements; b, CT scan data fed to the Artec 3D Geomagic Freeform software to render a 3D model for morphometric measurements.
Fig. 2 a, scanning of the dried lumbar vertebrae to generate a Geoform for morphometric measurements; b, CT scan data fed to the Artec 3D Geomagic Freeform software to render a 3D model for morphometric measurements.
a),30 andiii.From the 3D lumbar vertebrae model was (via Geomagic Freeform plus software, Version V20190.61) generated from a 1 mm thin CT scan slice of the Lumbar spine of patients who were advised to have a CT scan of the abdomen for reasons other than related to the vertebral column (Fig. 2b).31

Linear and angular measurements from 100 sets of dry lumbar vertebrae (comprising L1 to L5) were taken for the study, accumulating data from 500 pairs or 1000 pedicles. The exact number of lumbar vertebrae was used to generate 3D Geoforms. At the same time, CT scan data of 30 consecutive patients (19 male and 11 female) within the age range of 27–58 years old and an average age of 41 years were retrospectively obtained to generate a 3D lumbar vertebrae model for measurements. The dried bones were from 35 male and 25 female cadavers, averaging 42.3 ± 4.6 years for males and 39.1 ± 4.1 years for females.

Dried bone with any deformity or damage was excluded from direct bone measurements as well as from 3D scans too. Similarly, CT scans showing any bony deformity in the lumbar region or any patient history with trauma were excluded from the study.

Linear measurements of dried bones were taken with Vernier calipers (with an accuracy of 0.1 mm), whereas the goniometer (accuracy of 0.1°) was utilized for angular measurements on the samples. The 3D rendered images’ measurements were by scanning the dried bones, and the CT scans were taken by inbuilt measurement software (via Geomagic Freeform plus software, Version V20190.61) of the rendering format.

The parameters of the pedicle obtained via the three modalities were (Fig. 1).i.Transverse Pedicle Width (TPW) – the minimum mediolateral diameter of the pedicle's outer cortex, often measured at the isthmus of the pedicle and is also referred to as pedicle width.ii.Sagittal Pedicle Width (SPW) – the minimum supero-inferior diameter of the pedicle's outer cortex, referred to as pedicle height.iii.Pedicle + Body Length (PBL) along the central axis – the distance between the point of intersection and the outer cortex of the body in the central axis, often mentioned as chord length or depth of the anterior cortex along the midline axis in literature.32,33iv.Pedicle + Body Length (PBL) along the pedicular axis – the distance between the point of intersection and the outer cortex of the body in the pedicular axis, often mentioned as chord length or depth of the anterior cortex along the pedicular axis in literature.32,33v.Transverse Pedicle Angle (TPA) – the angle between the pedicular axis and the sagittal plane.vi.Sagittal Pedicle Angle (SPA) – the angle between the pedicular axis and the transverse plane.

2.1

2.1 Statistical analysis

Data from the three observation modes were tabulated in the Statistical Package for the Social Sciences software (IBM SPSS Statistics for Windows, Version 27.0). The central tendency measures of the mean were calculated for the dataset. The student's t-test was applied to obtain the p-value for determining the statistical differences between the datasets. The student's test for paired two mean samples was used between the lateral values obtained by bony and Geoform of bone scan datasets and between them, as these data have identical study specimens. In comparison, the student's test for two samples assuming equal variances was applied between the data sets of the bony measurements and the Geoform from CT scan studies as they are observed in different specimens but belonged to the same geographical population.

3

3 Results

The linear and angular measurements were compared and statistically analysed using a student's two-tailed t-test, where a p-value less than 0.05 was considered significant.

3.1

3.1 Linear measurements

The linear pedicular dimensions were observed in all the lumbar vertebrae via three modes of morphometry. The data kept by bone morphometry and measurements taken on Geoform created by scanning the bones were similar with no statistical differences (p-value <0.05). Therefore, the data values of both the measurement forms are presented in Table 1, but for the explanation, only bone morphometry data and CT scan Geoform data are being used.

Table 1 Linear and angular parameter values of the lumbar pedicles obtained via three modes of measurements.
Parameter Study mode L1 L2 L3 L4 L5
SPW Bone Right 14.25 ± 0.45 13.8 ± 0.4 13.4 ± 0.7 14.4 ± 0.5 13.75 ± 1.35
Left 13.95 ± 0.55 14.25 ± 0.45 13.45 ± 1.05 13.95 ± 0.35 12.85 ± 1.75
Bone Geoform Right 14.37 ± 0.43 13.7 ± 0.5 13.28 ± 0.9 14.2 ± 0.43 13.78 ± 1.15
Left 13.84 ± 0.55 14.2 ± 0.23 13.35 ± 1.7 13.82 ± 0.31 12.63 ± 1.5
Geoform CT scan Right 14.83 ± 0.42 14.37 ± 0.71 13.91 ± 0.64 14.96 ± 0.93 14.15 ± 1.27
Left 14.58 ± 0.61 14.56 ± 0.41 13.7 ± 1.18 14.62 ± 0.28 13.63 ± 1.93
TPW Bone Right 8.02 ± 1.91 6.4 ± 1.3 11.25 ± 2.18 9.75 ± 2.13 10.48 ± 2.49
Left 7.94 ± 1.80 6.37 ± 1.44 11.17 ± 2.32 9.75 ± 2.14 10.58 ± 2.42
Bone Geoform Right 8.01 ± 1.87 6.41 ± 1.31 11.21 ± 2.15 9.73 ± 2.11 10.3 ± 2.26
Left 7.9 ± 1.8 6.3 ± 1.47 11.27 ± 2.28 9.73 ± 2.1 10.17 ± 2.36
Geoform CT scan Right 8.13 ± 0.53 6.6 ± 1 11.7 ± 1.06 9.9 ± 1.08 10.23 ± 0.7
Left 8.04 ± 0.44 6.83 ± 1.09 11.23 ± 1.4 9.92 ± 1.03 10.5 ± 0.7
TPA Bone Right 9.15 ± 0.35 13.4 ± 1.3 15.1 ± 0.4 18.75 ± 0.5 26 ± 0.9
Left 8.6 ± 1.02 11.5 ± 0.67 13.7 ± 1.5 18.3 ± 1.7 24.6 ± 0.94
Bone Geoform Right 8.09 ± 0.37 13.06 ± 1.27 14.88 ± 0.34 18.3 ± 0.47 25.8 ± 0.84
Left 8.04 ± 1 10.79 ± 0.44 13.3 ± 1.7 18.42 ± 1.63 25.02 ± 1.04
Geoform CT scan Right 9.7 ± 0.5 13.83 ± 0.7 15.834 ± 0.783 19.05 ± 0.53 27.06 ± 0.48
Left 8.95 ± 0.62 12.62 ± 0.61 13.88 ± 0.921 19.063 ± 0.67 25 ± 0.54
SPA Bone Right 6.35 ± 1.45 6.17 ± 1.25 5.8 ± 1 3.62 ± 1 3.6 ± 1.3
Left 5.7 ± 1.1 5.25 ± 1.15 4.1 ± 1 3.9 ± 1 2.45 ± 1.35
Bone Geoform Right 6.05 ± 1.27 6 ± 1.03 5.61 ± 1.2 3.5 ± 0.83 3.4 ± 1.73
Left 5.83 ± 1.31 5.8 ± 1.07 4.34 ± 1.17 3.94 ± 1.07 2.51 ± 0.82
Geoform CT scan Right 6.62 ± 0.7 6.3 ± 1 5.93 ± 0.74 3.69 ± 0.47 3.88 ± 0.8
Left 5.8 ± 0.51 5.81 ± 0.87 4.61 ± 0.83 4 ± 0.53 2.6 ± 0.27
PBL along the central axis Bone Right 38.1 ± 1.5 37.2 + 2.3 40.3 + 1.1 38.9 ± 0.9 37.5 ± 2.5
Left 38.2 ± 1.8 37.5 + 1.2 39.3 ± 1.7 37.04 + 1.3 36.14 ± 0.73
Bone Geoform Right 38.01 ± 1.42 36.82 + 2.1 39.9 + 1.03 38.57 ± 1 37.35 ± 2.28
Left 38.24 ± 1.73 37.45 + 1.18 39.01 ± 1.66 36.84 + 1.25 35.78 ± 0.51
Geoform CT scan Right 39.1 ± 0.45 38.35 + 0.3 40.93 + 0.71 40.3 ± 0.76 38.35 ± 0.75
Left 39.03 ± 0.35 38.17 + 0.28 40.43 ± 0.53 37.07 + 0.69 36.87 ± 0.583
PBL along the pedicle axis Bone Right 42.9 ± 1.52 43.15 ± 1.75 44.2 ± 1.35 43.8 ± 1.48 44.7 ± 1.54
Left 43.45 ± 1.07 44.3 ± 1.6 43.9 ± 1.13 42.16 ± 1.6 45.6 ± 1.42
Bone Geoform Right 42.78 ± 1.5 43.12 ± 1.67 44.23 ± 1.32 43.68 ± 1.33 44.47 ± 1.5
Left 43.5 ± 1.2 44.24 ± 1.46 43.83 ± 1.3 42.11 ± 1.47 45.16 ± 1.38
Geoform CT scan Right 43.48 ± 0.58 44.61 ± 0.49 45.93 ± 0.72 44.62 ± 0.33 46.14 ± 0.49
Left 44.05 ± 0.41 44.85 ± 0.52 44.79 ± 0.61 43.59 ± 0.43 46.86 ± 0.8

Data regarding TPW of L1 to L5 by bone morphometry from around the globe was tabulated (Supplementary Table) and compared with the present study data by applying Student's t-test for the sample with means to determine the statistical significance. The null hypothesis was generated that the data compared with the present study data are similar. The t-test presented that none of the data, either from bone morphometry or via radiological studies, of the Asian, European, or American populations had any statistically significant relationship with that of the present study (p-value >0.05). Hence, the null hypothesis could not be rejected.

The pedicles were the widest in the transverse plane at L3 on both sides via both the bone morphometry (with a range of 5.35–14.73 mm) and on Geoform created by CT scan data (with a range of 5.71–14.83 mm), while the parameter was the narrowest bilaterally at L2 vertebra for bone (4.63–8.53 mm) and CT scan measurements (5.92–9.12 mm). The pedicles of vertebrae L1, L2, and L4 had a transverse diameter of less than 5 mm in 2% of each level. At the same time, 2.5% of the pedicles at L3 were less than 6 mm wide.

The sagittal pedicle width at L4 vertebrae was observed to be the widest bilaterally on the bone (with a range of 5.85–16.47 mm), and the Geoform created by CT scan data (with a range of 6.32–17.38 mm), while L3 had the narrowest pedicle on either side with a range of 4.73–15.19 mm for bones and 5.36–16.19 mm for CT scan measurements.

The PBL of the pedicle screws requires the cortical part of the pedicle and the body of the vertebra. Therefore, it was measured in two axes: the central and the pedicle axis. The PBL along the pedicular axis is longer than the central axis at all the lumbar levels. The linear measurement along the pedicular axis was longest at L5 bilaterally via both modes, with a range of 18.2–47.31 mm for bones and 21.03–49.28 mm for CT scan morphometry. The L1 vertebrae had the shortest PBL for the right pedicle (with a range of 16.71–44.11 mm for bone and a range of 17.83–47.35 mm for CT scan Geoforms), and L4 was observed to be the shortest on the left side (with a range of 16.2–44.7 mm for bones and a that of 16.84–45.37 mm for CT scan measurements). Along the central axis, PBL was longest for L3 bilaterally for bony (16.57–41.07 mm) and CT scan measurements (19.31–43.702 mm), while the right pedicles of L2 vertebrae had minimal measurements in bone (15.03–38.1 mm) as well as CT scan study (17.06–41.94 mm), and the L5 had the minimal dimensions for PBL on the left side for both modes of measurements (having a range of 15.11–37.83 mm for bones and 17.13–41.66 mm for CT scan Geoforms), respectively.

3.2

3.2 Angular measurements

Similar to the linear measurements, the pedicles angular measurements (TPA and SPA) were taken via the three study modes. The TPA for bony measurements presented a statistical difference (p-value <0.05) between the values of the two sides of the bony vertebrae added between the CT scan Geoform measurements obtained for both sides of the vertebrae. On the other hand, the SPA values had no significant relationship to present within either of the study modes.

The TPA on analysis was observed to increase as one goes down the spine from L1 to L5, with a steep rise between L4 and L5. In contrast, the SPA decreased as we went caudally toward the L5 vertebrae. The observation made for TPA and SPA were uniform in all study modes (Table 1).

4

4 Discussion

Transpedicular screw/rod implantation has a much more comprehensive application when compared to rods, hooks, and wires, as they are biomechanically more superior and provide more desirable outcomes in segmental fixation post-decompression in spinal disorders such as fractures, scoliosis, and other degenerative instabilities.32–39 Though factors related to the pedicular implants, such as their design, penetration depth, and diameter, or those related to the bone mineral density, or the intraoperative fallacies may lead to untoward complications such as cerebrospinal fluid leakage due to meningeal damage or injury to the nerves and vessels. Sound anatomic knowledge regarding the dimensions and angular deviations of the pedicle concerning clinically relevant landmarks of the human body can minimize many device and procedure related complications.

Many studies have presented linear and angular morphometry data of pedicles in different populations around the globe via cadaveric spine studies, dried bone measurements, and radiological data from plain radiographs and CT scans. Though the data is abundant, with the broad application of the procedure, many studies have reported a misplacement rate of 5–41% and a success rate of 57–75% with the free-hand technique of instrumentation, the most common technique for pedicle implantations.40–45 These rates can be improved with the help of numerous image-guided techniques such as fluoroscopic-assisted, intraoperative navigation, and robotic-assisted surgeries. However, these are mostly not affordable by institutions of developing demographics and have their demerits. The data available in the literature presents variation based on gender, age, and ethnicity. The morphometric data offers an interpretation concerning measurement values of the two sides of the pedicle within an individual. This entails that even after being supposed to be mirror images of each other, variation exists between two different pedicles irrespective of being considered within an individual or between different individuals. Pre-operative knowledge about these variations, whether linear or angular, helps to plan the procedure concerning the appropriate size of the implant and the angular approach to minimize complications. The present study provides linear and angular pedicular measurements via three modes to ensure the accuracy of the data within the study population.

4.1

4.1 Pedicle width

The diameter of the pedicular screw to be inserted depends on the TPW. Therefore, this parameter is more critical than the sagittal width of the pedicle. The TPW values in subsequent lumbar vertebrae in the caudal direction present with a non-uniform increasing trend in all the reported literature except for those noted in bone morphometry by Panjabi et al., 1991 in the American population, Chaynes et al., 2001 in the European population, and Simpson et al., 2016 in the computed tomographic study of the American population (Fig. 3a). The trend of TPW in Lumbar vertebrae down the spine for the present study was most peculiar as L3 pedicle was observed to have maximum width among the contemporary studies (Fig. 3a & b).

a, c - Comparing the present study's transverse (TPW) and sagittal pedicular width (SPW) with previous literature via bone morphometry and b, d - radiological data.
Fig. 3 a, c - Comparing the present study's transverse (TPW) and sagittal pedicular width (SPW) with previous literature via bone morphometry and b, d - radiological data.

Variations in mean sagittal pedicle width were also observed, compared, and analysed among the data from Asian, American, and European populations with a range of 11.4–20.43 mm thickness for all lumbar vertebrae. Among the Asian studies, only the data from Western India25,28 for SPW of L2, L3, and L5 were different from that of the present study with statistical significance (p-value <0.05 with Student's t-test for the sample of means). The SPW of western Indians was slightly larger, with a decreasing trend as one moves caudally in the Lumbar spine. In contrast, a zig-zag trend was being followed in the concerned parameter for the present study (Fig. 3c). Among the American and European studies, the data from the Swiss,24 France,18 and Greek20 populations had statistically significant differences from the present population for SPW, while all the American studies6,16,21,26 had similar data to our research. A non-linear trend of SPW for different lumbar pedicles was observed among the studies. The radiological study data of Asian populations from Saudi Arabia15 and western India25 were related to the present study with a statistically significant difference for L2, L3, and L5. In contrast, the rest of the observed data from different studies were similar (Fig. 3d).

4.2

4.2 Pedicle angle

The pedicle of the lumbar vertebrae presents with transverse and sagittal angles. TPA data from bone morphometry and radiological studies show a trend of increasing angles with caudal angulation of the pedicles concerning the transverse plane of the body passing over the cranial surface of the respective vertebral body from L1 to L5 across populations. Tan et al., 2002 observed a single exception to the observation in the Singaporean population,29 which reported the pedicular axis to be laterally directed with an increasing trend in the TPA. Tan et al., 2002 said that TPA bilaterally has similar values and direction. The statistical analysis of the bony and radiological data determined significant differences mainly between the Asian19,25,29 studied population and an American study (Fig. 4a & b).21

a, c - Comparing the present study's transverse (TPA) and sagittal pedicular angle (SPA) with previous literature via bone morphometry and b, d - radiological data.
Fig. 4 a, c - Comparing the present study's transverse (TPA) and sagittal pedicular angle (SPA) with previous literature via bone morphometry and b, d - radiological data.

The SPA data, when analysed, presents with some interesting findings. The present study observed a decreasing angulation of the pedicle, thus approaching the transverse plane going down the spine. The data presented to have statistically significant differences with that of the Swiss,24 Turkish,23 western India,25 and Singaporean29 population in bone morphometrical studies. The Singaporean study reported that while approaching the transverse axis down the spine, the pedicular axis changed its alignment from cranial to caudal direction in L4 and L5 vertebrae (Fig. 4c). Similar to Tan et al., 2002, the change in pedicular axis direction was also reported in western India population25 at L5 level radiologically (Fig. 4d).

A different school of thought regarding the pedicular axis direction in the sagittal plane (SPA) was explained by Simpson et al., 2016. They consider the pedicular axis to be directed in the caudal direction from L1 to L5; thus, as one moves down the spine, the SPA increases significantly and uniformly from L2 to L5.

The pedicular angle is essential with respect to screw or plate implantation, as slight deviation can lead to a medio-lateral or supero-inferior cortical breach and cause neurological, visceral, or vascular injury or may lead to cerebrospinal fluid leakage. The literature reports that lateral cortical breach is more common and can be avoided with proper guidance or experience.36

4.3

4.3 Pedicle + body length (PBL)

“The longer the screw, the better the purchase,” the dictum holds true but not too much in clinically appreciable terms.33 While performing pedicular screw fixation, the anterior cortical purchase is not advised as this may lead to the breach and may damage the viscera and vessels.32 Among the Lumbar vertebrae, L2 (with a range of 37.24–49.7 mm across populations in different modes of observation) usually was reported to have the longest PBL along the central axis7,16,22,24,32,33 whereas the same for the present study was observed at L3 (with a range of 38.4–42.18 mm in different modes of observation). The PBL along the pedicular axis was observed to be longer than at the central axis at all lumbar vertebrae in the literature and in the present observation. Most of the reported data7,16,22–25,32,33 on PBL along the pedicular axis are significantly different from the current study data, delivering the information that no two populations have a common PBL. Along the pedicular axis, PBL was observed to be longest at different Lumbar levels for different populations, while for the present study population, it was longest at L5 vertebrae (Fig. 5).

a, c - Comparing the present study's pedicle and body length along the pedicular and central axis with previous literature via bone morphometry and b, d - radiological data.
Fig. 5 a, c - Comparing the present study's pedicle and body length along the pedicular and central axis with previous literature via bone morphometry and b, d - radiological data.
5

5 Conclusion

The present study revealed significant difference among multiple parameters observed via different modes. The information with respect to pedicle width (TPW at L3, SPW at L4 is maximum) and PBL (longest along the pedicular axis) will help to determine the size of the pedicle screw. In contrast, the data acquired on pedicle angle presents the clinician with pre-operative knowledge regarding the direction and angulation of the pedicular axis. Also, the fact that TPA increases and SPA decreases caudally. Due to the complicated inner structure of the pedicle, the pre-operative determination of pedicle morphometry and its relationship with adjacent bony landmarks is restrained. These evidences are obligatory while performing internal fixation to avoid any untoward complication of injury to the nerve, viscera, or vessel.

CRediT author statement

Conceptualization: AP, SKG; Data curation: AP, RKN; Formal analysis: RKN, PKS; Methodology: AP, RKN; Project administration: AP, SKG; Visualization: RKN; Writing - original draft: RKN; Writing - review & editing: RKN, AP, SKG, PKS.

Funding

This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

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