Pedicle Morphometry of Sub Axial Cervical Spine using Computed Tomography Scans among Adult Ugandan Population
Summary (2 min read)
- Accurate placement of pedicle screws in the sub axial cervical spine requires precise understanding of vertebrae anatomy, also known as Background.
- The objective of the study was to determine the morphometric dimensions of pedicles in the sub axial cervical spine among the adult Ugandan population.
- Eligible participants were consecutively recruited into the study.
- The sagittal angles decreased as one moved from C3 to C7.
- There are a number of well researched and documented sub-axial cervical spine fixation methods for different pathologies.
- Therefore, the objective of this study was to describe the morphometric dimensions of the sub axial cervical spine pedicles among adult Ugandans using computed tomography (CT) scans.
- This machine was a 2013 model, installed in January 2014 and was calibrated regularly.
- The demographic characteristics of patients, whose images were included, were noted.
- The following pedicle morphometric measurements were taken;.
- Inner medio-lateral diameter of the isthmus of the pedicle or width of cancellous core, also known as Inner pedicle width.
Description of study participants
- A total of 70 participants were enrolled into the study, 49 (%) were males.
- The age of the participants ranged from 19 to 76 years with a median age of 33.5years and the interquartile range was 20.
- A total of 700 sub axial cervical spine pedicles (C3-C7) were studied.
Pedicle width (PW)
- The mean PW was smaller in females than in males at all levels (P<0.05).
- The results are summarized in table 1 below.
Pedicle chord length
- The mean chord length was smaller in females than in males at all levels (P<0.05).
- There was weak correlation between chord length and BMI.
- The results are summarised in table 2 below.
Pedicle axial angle
- There was no statistically significant difference between genders at any level (p>0.05).
- The results are summarized in table 3 below.
Pedicle Height (PH)
- The mean PH was smaller in females than in males at all levels (P<0.05).
- There was a gradual increase in mean PH advancing caudally in the sub axial cervical spine.
- There was no correlation between PH and BMI at all levels.
- The results are summarised in table 4 below.
Pedicle sagittal angle (PSA)
- There were no statistical differences among genders at all levels (P>0.05).
- The results are summarised in table 5 below.
- 11, 12) and this can be explained by the fact that most patients who required cervical CT scans were those involved in trauma of which most are males.
- This was in keeping with the findings of the studies done locally for thoracic and lumbar spines as well as studies done in other populations such as Thailand and in the caucasians (3, 13).
- This could be due the fact that genetically females have a relatively smaller and shorter stature compared to male counter parts.(14, 15) Pedicle endosteal /inner width Pedicle endosteal width in this study was the smallest parameter of all parameters and it continuously increased from C3 to C7 and this was in keeping with previous studies (3, 16, 17).
- The pedicle width of the Ugandan population studied is smaller than that reported in studies elsewhere among Europeans and Americans as reported a systematic review study (18).
- Hence it is only at C7 that a 3.5mm pedicle screws can be inserted bilaterally in both males and females because they have endosteal minimum diameter of more than 2.5mm.
- The chord length was longer in men than in female counterparts and the differences was statistically significant (p<0.05) at all levels which was in agreement in other studies(21).
- The overall pedicle endosteal width is less than 4mm at all levels in both genders and it increases from C3 to C7 Pedicle endosteal width is smaller than pedicle height dimensions at all levels hence it is the primary dimension used to determine the screw diameter and it increases caudally.
- The pedicles of the upper sub axial cervical spine are oriented cranially then become horizontal in the lower sub axial cervical pedicles and they are oriented medially to the midline Pedicle cord length increases caudally and it’s the determinant for the screw length.
- There is no correlation between pedicle dimensions and BMI in the study population.
- A 4.5mm and 4mm pedicle screw diameter is not safe to be used in the sub axial cervical spine transpedicular fixation among Ugandan populations due the smaller pedicle width.
- Hence advise the different spine implant designers and manufacturers to customize cervical spine pedicle screws to Uganda’s population due to the smaller sizes of their dimensions as compared to other populations.
- The pedicle screw length ranging from 29mm to 32mm and axial angulation of 500 from the midline is appropriate in their population.
- Transpedicular screw insertion should be avoided in higher sub axial cervical pedicles because such attempt can be detrimental in Uganda’s population because of the smaller pedicle dimensions.
Ethics, approval and consent:
- Approval for this study was obtained from the School of medicine Research and Ethics Committee of Makerere University and Nsambya Hospital Research and Ethics Committee.
- Written informed consent was obtained from all participants.
- The data for this study is available on request and interested researchers may submit queries related to data access to SOMREC (firstname.lastname@example.org) or corresponding author (email@example.com).
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"Pedicle Morphometry of Sub Axial Ce..." refers result in this paper
...8 At all levels, the pedicle height was larger than the pedicle width and this trend compared well with studies done elsewhere(12, 13, 16, 19, 20)....
...In this study 70% of the participants were males which was in keeping with other similar studies that had a higher ratio of males to females (6, 11, 12) and this can be explained by the fact that most patients who required cervical CT scans were those involved in trauma of which most are males....
"Pedicle Morphometry of Sub Axial Ce..." refers background in this paper
...Many indicated that there are inter racial differences in the pedicle morphometric (6-10)....
"Pedicle Morphometry of Sub Axial Ce..." refers result in this paper
...The pedicles in this study were directed more medially as compared to the previous studies conducted among the Chinese, European and American populations.(16, 24)....
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Q1. What have the authors contributed in "Pedicle morphometry of sub axial cervical spine using computed tomography scans among adult ugandan population" ?
The objective of the study was to determine the morphometric dimensions of pedicles in the sub axial cervical spine among the adult Ugandan population. The authors conducted a cross sectional study from March to November 2019 among adult Ugandans with a normal cervical CT scan at Nsambya hospital in Kampala. Eligible participants were consecutively recruited into the study. Results: A total of 700 sub axial cervical pedicles ( C3-C7 ) from 49 males and 21 female participants were studied.