|
|||||||||||||||||||||||||||||||||||||||||||
|
Morphometry of Lumbar Spine- A Holistic Comparative Study between Typical and Atypical Lumbar Vertebrae |
|||||||||||||||||||||||||||||||||||||||||||
|
Gyanaranjan Nayak, Sitansu Kumar Panda, Prafulla Kumar Chinara 1. Associate Professor, Department of Anatomy, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, Bhubaneswar, Odisha, India. 2. Professor, Department of Anatomy, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, Bhubaneswar, Odisha, India. 3. Professor, Department of Anatomy, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, Bhubaneswar, Odisha, India. |
|||||||||||||||||||||||||||||||||||||||||||
|
Correspondence Address : Dr. Gyanaranjan Nayak, Associate Professor, Department of Anatomy, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, Bhubaneswar, Odisha, India. E-mail: drgrn82@gmail.com |
|||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||
| ABSTRACT |  | ||||||||||||||||||||||||||||||||||||||||||
: Morphometry of body and neural arch of lumbar vertebrae is very crucial in manufacturing screws, interspinous implants as well as preoperative planning of surgeries involving dorsolumbar spine. Aim: To determine various dimensions of typical and atypical lumbar vertebrae. Materials and Methods: A descriptive osteological study was carried out which included 66 intact adult dry human lumbar vertebrae (53 typical and 13 atypical) which were free of any deformity or pathological features. All the 53 typical vertebrae were randomly obtained. The following parameters were measured with slide callipers- superior transverse diameter and superior antero-posterior diameters of vertebral foramen; transverse diameter, antero-posterior diameter and anterior height of vertebral body; width, height of pedicles; interpedicular distance; maximum thickness of lamina; length of transverse process; maximum length, maximum height and maximum central thickness of spinous process. The data was tabulated and analysed using Microsoft Excel software. Mean and standard deviation was calculated for each parameter. Unpaired t-test was applied and p-value was derived for parameters like width and height of pedicles, thickness of lamina and length of transverse process. The p-value<0.05 were considered as significant. Results: The vertebral foramen (superior transverse diameter- 20.41±2.54 mm, superior antero-posterior diameter- 13.3±2.04 mm); vertebral body (transverse diameter- 44.43±5.91 mm, antero-posterior diameter- 30.17±3.19 mm, anterior height- 24.01±1.84 mm); pedicle (width- 10.85±3.94 mm on left side and 11.04±4.01 mm on right side, height- 13.84±4.01 mm on left side and 13.8±1.93 mm on right side, interpedicular distance- 29.17±5.06 mm); lamina (thickness- 6.6±1.36 mm on left side and 6.85±1.34 mm on right side); transverse process (length- 20.94±4.01 mm on left side and 21.51±4.5 mm on right side); spinous process (maximum length- 26.01±3.73 mm, maximum height- 19.92±4.03 mm, maximum central thickness- 6.42±1.41 mm). The mean transverse diameter and antero-posterior diameter of vertebral foramen of atypical lumbar vertebrae were higher than those of the typical lumbar vertebrae and these differences were significant (p-value of 0.0001 for transverse diameter and p-value of 0.005 for antero-posterior diameter). Conclusion: Most of the parameters of atypical lumbar vertebrae were found to be more compared to those of typical lumbar vertebrae. This inference should be kept in mind during fixation of lumbar inter-spinous implants, designing of pedicular screws and spinal grafting. | |||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||
| Keywords : Dimensions, Lumbar vertebral column, Neural arch, Vertebral body | |||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||
| INTRODUCTION | | ||||||||||||||||||||||||||||||||||||||||||
Dimensions of lumbar vertebrae are of utmost importance in diagnosing lower back pain and lumbar spinal stenosis. In lumbar spinal stenosis, there’s reduction of antero-posterior and lateral dimensions of the lumbar vertebral canal resulting in low backache (1). Developmental lumbar spinal canal stenosis can be due to anomalous neural arch, pedicles, laminae and articular processes resulting from shortening of lateral sagittal diameters of spinal canal due to thickened laminae and articular processes of lumbar vertebrae (2). Another cause of low back pain is lumbar degenerative disc disease which results from deteriorated lumbar intervertebral discs. Late phase lumbar degenerative disc disease is treated by interspinous process implant which is a minimally invasive novel surgical procedure (3). This surgical procedure has many advantages, but complications such as implant device migration and spinal fracture may occur (4). So, thorough knowledge of dimensions of lumbar spinous processes is important for proper interspinous process implantation to prevent post-operative complications (5). Pedicles of lumbar vertebrae are frequently utilised as sites of fixation for lumbar spinous implants (6). The pedicles of lumbar vertebrae are used to gain access for injecting acrylic cement into the body of fractured vertebrae for their stabilisation, restoring vertebral height and reducing spinal deformity (7). Various devices such as rods, plates or wires are fixed to the vertebral column by screws for immobilisation (8). Transpedicular screw implantation techniques have become popular in recent years (9). The pedicles provide an excellent implantation site for screw fixation in reconstructive spine surgeries imparting proper stability. However, misplaced and misdirected pedicle screw may injure pedicle cortex, nerve root, zygapophyseal joints and other vital structures (10). It’s imperative to have knowledge of pedicle dimensions for safe placement of pedicle screws. The pedicle screw is inserted through posterior surface of the pedicle into the vertebral body. The selection of the screw to be used is determined by the dimensions of the pedicle. So, pedicular morphometry is of immense help in preoperative planning as well as designing pedicle screws and other implantable devices (11). The dimensions of transverse processes along with those of the pedicles of vertebrae, determine the better acceptance of spinal grafts during spinal surgery (12). Thus, the morphometry of lumbar vertebrae is of paramount importance in spine surgery and diagnosing low back pain. Therefore, an attempt was made to perform the morphometric analysis of the body and neural arch of lumbar vertebrae in a single study as only few such holistic studies (1),(12) involving both the body and neural arch of lumbar vertebrae together have been performed till date. | |||||||||||||||||||||||||||||||||||||||||||
| MATERIAL AND METHODS | | ||||||||||||||||||||||||||||||||||||||||||
A descriptive osteological study was conducted which included 66 dry lumbar vertebrae (53 typical and 13 atypical). The vertebrae were procured from the departmental museum of Anatomy of a Medical College of Eastern India. All the vertebrae belonged to adult males as per the record of the museum. The vertebrae were segregated into two groups: typical and atypical. Broken and deformed vertebrae with obvious pathological derangements were excluded from the study. The vertebrae were measured with slide callipers and recording was observed in mm with a precision reading from 0.01 mm. The following parameters were measured (1),(12). A. Superior transverse and superior antero-posterior diameters of vertebral foramen (Table/Fig 1)- Superior transverse diameter of vertebral foramen (AB) was taken as the maximum transverse distance across superior aspect of vertebral foramen. Superior antero-posterior diameter of vertebral foramen (CD) was taken as the maximum antero-posterior distance across superior aspect of vertebral foramen. B. Transverse diameter (Table/Fig 2), antero-posterior diameter (Table/Fig 2) and anterior height (Table/Fig 3) of the vertebral body-Transverse diameter of body (EF) were taken as the maximum transverse distance across the superior surface of vertebral body. Antero-posterior diameter of body (GH) was taken as the maximum antero-posterior distance across the superior surface of vertebral body. Anterior height of vertebral body (IJ) was taken as the maximum vertical measurement across anterior surface of vertebral body. C. Width (Table/Fig 2) and height (Table/Fig 3) of the pedicles as well as interpeduncular distance (Table/Fig 1)-Width of pedicle (KL) was taken as the maximum transverse measurement on the superior surface of vertebral pedicle. Height of the pedicle (MN) was taken as the maximum vertical measurement of pedicle i.e., from the highest point of superior surface of pedicle to the lowest point on the inferior surface of pedicle. Interpedicular distance (OP) was taken as the transverse distance across the upper ends of the two superior articular processes of vertebra. D. Thickness of the lamina- It was taken as the maximum measurable thickness of the lamina. E. Length of the transverse process (QR in (Table/Fig 1)): It was measured as the distance across lateral extreme of superior aspect of vertebral foramen and tip of transverse process. F. Maximum length (Table/Fig 2), maximum height (Table/Fig 3) and maximum central thickness of the spinous process- Maximum length of the spinous process (ST) was measured as the distance between the most anterior point and most posterior point on the superior border of spinous process. Maximum height of spinous process (UV) was measured as the vertical distance between most posterior points on superior and inferior borders of spinous process. Maximum central thickness of spinous process was measured as the maximum transverse distance between the central points of lateral surfaces of spinous process. All the measurements were repeated thrice by different observers to exclude interobserver variations. STATISTICAL ANALYSIS The observations were tabulated and analysed using Microsoft Excel software. Mean and standard deviations were obtained for each of the parameters. Unpaired t-test was applied and p-value was calculated for parameters like width and height of pedicles, thickness of lamina and length of transverse process. Difference was considered to be statistically significant if p-value obtained was <0.05. | |||||||||||||||||||||||||||||||||||||||||||
| RESULTS | | ||||||||||||||||||||||||||||||||||||||||||
The mean transverse diameter and antero-posterior diameter of vertebral foramen of atypical lumbar vertebrae were higher than those of the typical lumbar vertebrae (Table/Fig 4). These differences were significant (p-value of 0.0001 for transverse diameter and p-value of 0.005 for antero-posterior diameter). The vertebral foramen of atypical lumbar vertebrae was strictly of triangular shape while in typical lumbar vertebrae, it was triangular with slightly round to oval contour. The vertebral foramina of atypical lumbar vertebrae were larger compared to that of typical lumbar vertebrae. The atypical lumbar vertebrae were found to possess more massive bodies than typical lumbar vertebrae. The mean transverse diameter, antero-posterior diameter and anterior height of vertebral body were higher for atypical lumbar vertebrae compared to typical lumbar vertebrae (Table/Fig 5). However, the values were not statistically significant. The atypical lumbar vertebrae presented wider pedicles than typical lumbar vertebrae. However, the typical lumbar vertebrae were found to have more mean height of pedicle than the atypical ones. The mean pedicular width of atypical and typical lumbar vertebrae was more on the right side compared to left. The difference was not found to be statistically significant. However, the height of the pedicle was found to be higher on the left side in atypical lumbar vertebrae than right, the difference not being statistically significant. In typical lumbar vertebrae, the height of pedicle was more on the right side. The difference was not found to be statistically significant either (Table/Fig 6). The mean thickness of the lamina of typical lumbar vertebrae was higher than that of atypical lumbar vertebrae on left side (Table/Fig 7). The mean length of transverse process was higher for atypical lumbar vertebrae on both right and left sides compared to typical lumbar vertebrae (Table/Fig 8).The spinous processes of typical lumbar vertebrae possessed more mean length and height than atypical lumbar vertebrae (Table/Fig 9). | |||||||||||||||||||||||||||||||||||||||||||
| DISCUSSION | | ||||||||||||||||||||||||||||||||||||||||||
The superior transverse diameter and superior antero-posterior diameter of vertebral foramen is 20.41±2.54 mm and 13.3±2.04 mm in the current study. Einstein (14) has reported a mean superior transverse diameter of 23 mm (average lower limit of normal 18 mm) and a mean superior antero-posterior diameter of 16 mm (lower limit of normal 13 mm) for vertebral foramen of lumbar vertebrae in his study, which was in agreement with the current study. The transverse diameter of vertebral body ranged from 40.56 mm to 60.61 mm in atypical lumbar vertebrae and from 33.34 mm to 54.85 mm in typical lumbar vertebrae. The antero-posterior diameter of vertebral body ranged from 24.39 mm to 37.57 mm in the typical lumbar vertebrae and from 23.68 mm to 35.56 mm in the typical lumbar vertebrae. Azu A et al., have reported antero-posterior diameter of body ranging between 23 mm-32.7 mm (L1, female); 27.8 mm-42 mm (L1, male); 26.7 mm-37.7mm (L2,female); 25.5 mm-46 mm (L2, male); 23.9 mm-40.2 mm (L3, female); 27.7 mm-42.3 mm (L3, male); 27 mm-42.4 mm (L4, female); 27.4 mm-43 mm (L4, male); 31.5 mm-46.6 mm (L5, female); 31.9 mm-37.8 mm (L5, male) (1). In the current study, pedicular width was found to be 15.31±3.62 mm (left side) and 16.21±3.14 mm (right side) for atypical lumbar vertebrae. Pedicular width was 9.76±3.19 mm (left side) and 9.77±3.08 mm (right side) for typical lumbar vertebrae. Pedicular height was derived to be 14.05±2.98 mm (left side) and 12.38±2.67 mm (right side) for atypical lumbar vertebrae. Typical lumbar vertebrae presented a pedicular height of 13.79±1.65 mm on left side and 14.16±1.52 mm on the right side. Various authors have reported similar values. Singel TC et al., have reported average width at the mid-point of pedicle to be 9.52 mm in dry bones (14). Other average values reported for typical lumbar vertebrae are 7.18 mm on left side and 6.98 mm on right side by Tan SH et al., (15); 8.68 mm on left side and 8.68 mm on right side by Lien SB et al., (16). Patil BK and Bhuyan PS have reported the average width of pedicle of typical lumbar vertebrae at the midpoint of pedicle as 8.57±1.69 mm on the left side and 8.41±1.62 mm on right side. They have reported the average height of pedicle of typical lumbar vertebrae at the midpoint of pedicle as 13.9±1.39 mm on the right side (17). Chandni G et al., have reported pedicular width as 7±2 mm on right side and 8±2 mm on left side for typical lumbar vertebrae; 14±2 mm on right side and 14±2 mm on left side for atypical lumbar vertebrae. They have reported pedicular height as 13±1 mm on right side and 12±1 mm on left side for atypical lumbar vertebrae (18). Marasini RP et al., have reported average horizontal diameter of pedicle as 7.17 mm for first lumbar vertebra, 7.62 mm for second lumbar vertebra, 9.5 mm for third lumbar vertebra, 10.51 mm for fourth lumbar vertebra, 11.3 mm for fifth lumbar vertebra and average vertical diameter of pedicle as 15 mm for first lumbar vertebra, 15.28 mm for second lumbar vertebra, 15.21 mm for third lumbar vertebra, 13.44 mm for fourth lumbar vertebra, 12.59 mm for fifth lumbar vertebra (19). The interpedicular distance was established as 25.01±3.25 mm for atypical lumbar vertebrae and 35.28±4.92 mm for typical lumbar vertebrae in the present study. Mean interpedicular distance was established as 25.54 mm (L1), 27.03 mm (L2), 27.7 mm (L3), 28.62 mm (L4), 31.39 mm (L5) by Marasini RP et al.,. (19) and Azu A et al., have also reported similar interpeduncular distance as in present study (1). In the current study, the length of transverse process was found to be 21.05±3.15 mm on left side; 21.8±3.1 mm on right side for atypical lumbar vertebrae and 20.92±4.22 mm on left side, 21.44±4.8 mm on right side for typical lumbar vertebrae. Tyagi S and Narayan RK have reported similar length of transverse process as in present study (12). The values of maximum length, maximum height and maximum central thickness of spinous process for both atypical and typical lumbar vertebrae resembles with the findings of Tyagi S and Narayan RK and Ran B et al., [12,20]. Ran B et al., have established the average height of spinous process as 8.9-33.5 mm (male) and 7.6-28.4 mm (female) for typical lumbar vertebrae; 10.1-31.5 mm (male) and 7.8-25.6 mm (female) for atypical lumbar vertebrae and the central thickness of spinous process was measured as 7.94±1.9 mm (male) and 6.18±1.16 mm (female) (20). The current study provides a complete morphometry of lumbar vertebrae. The findings of the study will be highly relevant in orthopaedic surgery and radiological evaluation involving lumbar spine. Procedures such as lumbar spinal implantation, kyphoplasty and vertebroplasty of lumbar spine and lumbar laminectomy require detailed knowledge of the different dimensions of lumbar vertebrae. Limitation(s) It is recommended that cadaveric and radiological evaluation of the different dimensions of body and neural arch of lumbar vertebrae may be carried out in Indian population, which will further add on the information. The present study, being a drybone study, has not described the possible age and sex related variations of lumbar spinous morphometry. | |||||||||||||||||||||||||||||||||||||||||||
| CONCLUSION | | ||||||||||||||||||||||||||||||||||||||||||
The lumbar spine is a frequent site for injuries, osteoporosis and degenerative disorders like lumbar spondylosis. Morphometric data of the current study is relevant in radiology and spine surgeries for selection of pedicle screw and interspinous implant for operative repair of such disorders. The cadaveric and radiological studies can describe the variations in morphometry of lumbar spine in relation to age and sex which can enhance the knowledge rendered by the present study. | |||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||
| TABLES AND FIGURES |
|
||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||
Welcome : Guest
Users Online :
Original article / research
Home |
About Us |
Online First |
Current Issue |
Simple Search |
Advance Search |
Register |
Login |
Contact |
Privacy Policy |
Terms of Use
Author Support | Submit Manuscript | IJARS Pre-Publishing | Reviewer | Articles Archive | Access Statistics
Author Support | Submit Manuscript | IJARS Pre-Publishing | Reviewer | Articles Archive | Access Statistics
© 2024 INTERNATIONAL JOURNAL OF ANATOMY RADIOLOGY & SURGERY (IJARS), ISSN : 2277-8543.
EDITORIAL OFFICE : 1/9, Roop Nagar, Delhi 11000. Phone : 01123848553
EDITORIAL OFFICE : 1/9, Roop Nagar, Delhi 11000. Phone : 01123848553
* This Journal is owned and run by medical professionals *
