Ethnic origin plays an important role in bone morphometry. Studies examining the influence of coracoid process have focused primarily on adults and have not included people from diverse Asian ethnic backgrounds. Our goal was to explore ethnic differences in morphometry of coracoid among Asian population. We performed morphometric measurements of coracoid process on cadaveric shoulders and shoulder CT scans from 118 specimens. The cadaveric sample included Indian (46%), Chinese (27%), and Myanmarese (27%) subjects, while the CT scans sample included Chinese (67%) and Malay (33%) subjects. The morphometric measurements were performed using digital caliper and software developed at Golden Horses Health Sanctuary (GHHS). In the Indian cadaveric shoulders, the coracoid process is better developed than the other groups with the exception of the tip width of coracoid process. There are significant differences in almost all measurements (
Morphometric variations of the bone are clinically important. The scapula itself is a complex anatomic unit, so this draws the interest and attention of scientists and researchers to study the morphometry of the scapula [
This research is an analytic cross-sectional study that was conducted on 118 specimens. It consists of two independent parts: an anatomical study of formalin-fixed cadaveric shoulders and a retrospective radiological study of computed tomography scan of scapulae. The work was approved by the Ethical Committee of the Universiti Putra Malaysia (UPM) under the code UPM/TNCPI/RMC/1.4.18.1 (JKEUPM)/F2, approval number FPSK_Nov (13) 24 (EXP). All subjects had given informed consent before computed tomography (CT) scans examinations were performed. The coracoid processes of all 118 scapulae were analysed. The following areas were measured from the coracoid process (Figure Length of coracoid process (distance from the tip to the end of horizontal part) Tip thickness of coracoid process (superoinferior distance 1 cm posterior to the tip) Tip width of coracoid process (anteroposterior distance 1 cm posterior to the tip) Base height (maximum superoinferior distant of the base) Base width (maximum medial-lateral distant of the base).
(a) Front view of the right scapula illustrated the measurement taken: (1) A-B line: the length of coracoid process (CP); (2) C-D line: the base width. (b) Lateral view of the right scapula illustrated the measurement taken: (1) E-F line: the base width of CP; (2) G-H line: the tip thickness of CP. (c) Superior view of the right scapula illustrated the measurement taken: (1) A-B line: the length of CP; (2) C-D line: the base width; (3) I-J line: the tip width of CP.
The anterior aspect of 52 embalmed adult male shoulders was dissected. The age and race of the donors were recognized. In all cadaveric shoulders, the skin was separated from the deltoid and trapezius, and the deltopectoral groove was located. Next, the deltoid muscles were incised vertically to expose the coracoid process with all attachments. All attached muscles and ligaments were dissected out. After all attachments were dissected from their insertion, the anatomic feature of the coracoid process was visualized [
(a) Photograph showing digital caliper measuring the tip thickness of the coracoid process. (b) Photograph showing digital caliper measuring the length of the coracoid process.
Retrospective study analysis of 66 CT scans of shoulders taken as part of a standard CT using chest protocol was performed. The CT images were acquired using a Siemens Somatom Emotion 6 (kV (kilo voltage) = 110, mA (milliampere) = 21, rotation time = 0.8 second, and slice thickness 1.3 mm). CT scan images were uploaded in DICOM format to medical imaging software (e-film, version 2.1.2, Merge Healthcare, Milwaukee, WI). Three sequential axial images (1.3-mm in thickness, original magnification) of each of the 66 sites were selected (
Axial CT scan images showing the measurement of the tip of the coracoid process.
Axial CT scan images showing the measurement of the base of the coracoid process.
The results were presented as mean ± standard deviation (SD) from dual studies that were performed independently. The normality of data distribution was checked by skewness and kurtosis level. The statistical analysis was carried out using one-way analysis of variance (ANOVA) for data from cadaveric study and differences between ethnic groups were separated using Tukey HSD post hoc test, while the data obtained from CT scan was analysed by independent
A total of 52 male cadaveric shoulders (26 cadavers) were selected in this study. An expert anatomist did the selection of these cadavers based on their physical examination.
Table
Distribution of the cadavers according to sociodemographic characteristics.
Variable |
|
% |
---|---|---|
|
||
Indian | 12 | 46 |
Chinese | 7 | 27 |
Myanmarese | 7 | 27 |
|
26 | 100 |
|
||
Male | 26 | 100 |
|
||
20–30 | 2 | 7.6 |
30–40 | 7 | 26.9 |
40–50 | 7 | 26.9 |
50–62 | 9 | 34.6 |
Morphometric measurements of the coracoid process of the scapula among Chinese, Indian, and Myanmarese subjects.
Measurements | Indian ( |
Chinese ( |
Myanmarese ( |
---|---|---|---|
Length of coracoid process (mm) |
|
|
|
Tip thickness of coracoid process (mm) |
|
|
|
Tip width of coracoid process (mm) |
|
|
|
Base height of coracoid process (mm) |
|
|
|
Base width of coracoid process (mm) |
|
|
|
Morphometric measurements of right and left coracoid process.
Measurements | Indian | Chinese | Myanmarese | ||||||
---|---|---|---|---|---|---|---|---|---|
Right |
Left |
|
Right |
Left |
|
Right |
Left |
|
|
Length of the coracoid process (mm) |
|
|
0.91 |
|
|
0.69 |
|
|
0.88 |
Tip thickness of the coracoid process (mm) |
|
|
0.68 |
|
|
0.11 |
|
|
0.64 |
Tip width of the coracoid process (mm) |
|
|
0.80 |
|
|
0.83 |
|
|
0.73 |
Base height of the coracoid process (mm) |
|
|
0.74 |
|
|
0.26 |
|
|
0.77 |
Base width of the coracoid process (mm) |
|
|
0.61 |
|
|
0.73 |
|
|
0.22 |
All values are presented as mean ± SD in mm.
An expert radiologist selected a total of 66 shoulders’ CT scans from 33 normal subjects. Those subjects were visiting Golden Horses Health Sanctuary (GHHS) for regular medical checkup.
Table
Distribution of the subjects according to sociodemographic characteristics stratified by ethnicity.
Ethnicity |
|
Mean | SD | 95% CI for mean | Min | Max |
|
|
---|---|---|---|---|---|---|---|---|
Age (years) | Chinese | 22 | 40.54 | 4.22 | 38.67–42.42 | 33 | 47 | 0.22 |
Malay | 11 | 38.18 | 6.80 | 33.60–42.75 | 27 | 50 | ||
Height (cm) | Chinese | 22 | 163.95 | 9.40 | 159.76–168.13 | 147 | 181 | 0.46 |
Malay | 11 | 166.45 | 8.18 | 160.95–171.95 | 155 | 179 | ||
Weight (kg) | Chinese | 22 | 62.27 | 15.92 | 55.21–69.33 | 36.80 | 91.50 | 0.10 |
Malay | 11 | 71.56 | 13.73 | 62.33–80.78 | 43.60 | 94.60 | ||
BMI (kg/m2) | Chinese | 22 | 23.17 | 4.02 | 21.39–24.95 | 16.50 | 30.30 | 0.13 |
Malay | 11 | 25.45 | 4.13 | 22.67–28.22 | 18.10 | 32.40 |
Morphometric measurements of the length of the coracoid process for both ethnic groups stratified by sex.
Sex | Malay | Chinese |
|
||||
---|---|---|---|---|---|---|---|
|
Mean (mm) | SD (mm) |
|
Mean (mm) | SD (mm) | ||
Males | 14 | 39.14 | 1.16 | 20 | 41.80 | 1.47 | 0.001 |
Females | 8 | 34.25 | 1.28 | 24 | 36.20 | 2.02 | 0.01 |
All groups | 22 | 37.36 | 2.68 | 44 | 38.75 | 3.32 | 0.09 |
Morphometric measurements of the tip thickness of the coracoid process for both ethnic groups stratified by sex.
Sex | Malay | Chinese |
|
||||
---|---|---|---|---|---|---|---|
|
Mean (mm) | SD (mm) |
|
Mean (mm) | SD (mm) | ||
Males | 14 | 10.28 | 0.82 | 20 | 11.2 | 1.05 | 0.01 |
Females | 8 | 8.00 | 0.75 | 24 | 9.25 | 0.94 | 0.002 |
All groups | 22 | 9.45 | 1.37 | 44 | 10.13 | 1.39 | 0.06 |
Morphometric measurements of the base height of the coracoid process for both ethnic groups stratified by sex.
Sex | Malay | Chinese |
|
||||
---|---|---|---|---|---|---|---|
|
Mean (mm) | SD (mm) |
|
Mean (mm) | SD (mm) | ||
Males | 14 | 14.92 | 0.91 | 20 | 16.20 | 0.83 | 0.001 |
Females | 8 | 11.75 | 1.28 | 24 | 13.83 | 1.04 | 0.001 |
All groups | 22 | 13.77 | 1.87 | 44 | 14.90 | 1.52 | 0.01 |
Morphometric measurements of the base thickness of the coracoid process for both ethnic groups stratified by sex.
Sex | Malay | Chinese |
|
||||
---|---|---|---|---|---|---|---|
|
Mean (mm) | SD (mm) |
|
Mean (mm) | SD (mm) | ||
Males | 14 | 11.28 | 1.32 | 20 | 11.80 | 1.80 | 0.33 |
Females | 8 | 8.75 | 0.88 | 24 | 9.33 | 1.71 | 0.36 |
All groups | 22 | 10.36 | 1.70 | 44 | 10.45 | 2.06 | 0.85 |
On the other hand, similar results were found in the Malay subjects with the males having longer and thicker coracoid process (39.14 ± 1.16 mm and 10.28 ± 0.82 mm, resp.) than the females’ coracoid process (34.25 ± 1.28 mm and 8.00 ± 0.75 mm, resp.). Regarding the base of coracoid process, the males also had higher and thicker coracoid base (14.92 ± 0.91 mm and 11.28 ± 1.32 mm, resp.) than the females’ coracoid base (11.75 ± 1.28 mm and 8.75 ± 0.88 mm, resp.). Overall, the males had bigger coracoid process than females in both ethnic groups (Table
Morphometric measurements of the coracoid process stratified by gender for both ethnic groups.
Measurements | Malay | Chinese | ||||
---|---|---|---|---|---|---|
Males |
Females |
|
Males |
Females |
|
|
Length of coracoid process (mm) |
|
|
<0.001 |
|
|
<0.001 |
Tip thickness of coracoid process (mm) |
|
|
<0.001 |
|
|
<0.001 |
Base height of coracoid process (mm) |
|
|
<0.001 |
|
|
<0.001 |
Base thickness of coracoid process (mm) |
|
|
<0.001 |
|
|
<0.001 |
Morphometric measurements of the right and left coracoid process for both ethnic groups.
Measurements | Malay | Chinese | ||||
---|---|---|---|---|---|---|
Right |
Left |
|
Right |
Left |
|
|
Length of coracoid process (mm) |
|
|
0.92 |
|
|
0.89 |
Tip thickness of coracoid process (mm) |
|
|
0.93 |
|
|
0.52 |
Base height of coracoid process (mm) |
|
|
0.91 |
|
|
0.43 |
Base thickness of coracoid process (mm) |
|
|
0.62 |
|
|
0.56 |
Numerous reports have shown that the skeletal morphometry is influenced by different factors such as race and sex [
The comparison of the results of the morphometric analysis obtained from the present cadaveric study with the results of other studies is as follows: the mean length of males’ coracoid process in all three ethnic groups ranged between 39.19 ± 1.38 mm and 43.32 ± 1.54 mm and was smaller than Americans’ (45.6 ± 4.2 mm and 46.3 ± 3.3 mm) (Dolan et al. [
In reviewing the literature, very little data was found on morphometry of the coracoid process on in vivo population using CT scans [
In conclusion, variations in morphometric measurements of coracoid process between different Asian ethnic groups were observed in both cadaveric and radiological studies. These findings are very important, which gave the clue that Asians coracoid process sizes are entirely different and cannot be generally applied throughout the Asian population. Furthermore, the results showed that the measurements of the coracoid process in Asian are smaller than those of western populations.
The authors declare that there are no conflicts of interest regarding the publication of this paper.
Manal Fathi, Aye Aye San, and Ezamin Abdul Rahim designed the study. Manal Fathi collected the data and wrote the main manuscript text. Manal Fathi and Umar Ahmad analysed the data. Pike-See Cheah, M. Nizlan Nasir, and Paisal Hussin contributed to the discussion and revision of the manuscript. Fauziah Othman and Rozi Mahmud supervised the work. All the authors read and reviewed the manuscript before submission.
The authors are grateful to the staff of Anatomy Dissection Hall, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia (UPM), for their help during collecting data. In addition, the authors are grateful to the staff members and doctors of Golden Horses Health Sanctuary (GHHS) for generously providing the facilities for collection and analysis of the data.