|Year : 2020 | Volume
| Issue : 3 | Page : 173-176
Morphometric analysis of the acromion process of the scapula
Ananya Priya, Anjali Jain
Department of Anatomy, Christian Medical College, Ludhiana, Punjab, India
|Date of Submission||29-Dec-2019|
|Date of Decision||13-Jul-2020|
|Date of Acceptance||29-Jul-2020|
|Date of Web Publication||25-Jan-2021|
Department of Anatomy, Christian Medical College, Ludhiana, Punjab
Source of Support: None, Conflict of Interest: None
Context: This study was done to analyze the morphometric parameters of the acromion process of human scapulae. The knowledge of morphometry of acromion process is vital for orthopedic surgeons while performing surgeries like acromioplasty for the treatment of subacromial impingement syndrome and repair of rotator cuff tears. Aims: The aim was to study the morphometry of the acromion process of the scapula. Settings and Design: The study was conducted on 105 adult dry human scapulae of unknown age and sex. All damaged human scapulae were excluded from the present study. Subjects and Methods: Length, breadth, thickness of acromion process, coraco-acromial distance, and acromioglenoid distance were measured in millimeter using digital Vernier caliper. Statistical Analysis Used: Data were tabulated. Mean and standard deviation for each parameter were calculated using SPSS version 16.0. Results: The mean acromial length was 41.65 ± 7.57 mm, acromial width was 24.50 ± 2.91 mm, acromial thickness was 7.62 ± 1.34 mm, coracoacromial distance was 33.35 ± 6.12 mm, and acromioglenoid distance was 29.41 ± 4.65 mm. Conclusions: The data obtained in the current study can add to the knowledge that can aid in surgical procedures around the shoulder joint.
Keywords: Acromioplasty, morphometry, scapula, subacromial impingement syndrome
|How to cite this article:|
Priya A, Jain A. Morphometric analysis of the acromion process of the scapula. CHRISMED J Health Res 2020;7:173-6
| Introduction|| |
The acromion process projects forward almost at right angles, from the lateral end of the spine of the scapula. The subacromial space is defined inferiorly by the superior surface of the rotator cuff, superiorly by the coracoacromial arch and posteriorly by the posterior wall of the subacromial bursa. The subacromial space is related to acromioglenoid and coracoacromial distances. The lesser the subacromial space, the greater the chance of impingement syndrome.
The present study was done to evaluate the morphometric parameters of acromion process that can be beneficial in surgical resection of acromion process in subacromial impingement syndrome. People with acromion thickness >8 mm are more prone to impingement syndrome. Therefore, there is a need to smoothen the undersurface of the acromion to convert it to <8 mm thickness., Acromioplasty is an arthroscopic surgical procedure in which undersurface of the acromion process is shaved to provide enough space so that rotator cuff tendons may not pinch and pain of impingement is relieved.
Apart from this, dimensions obtained in this study can be of assistance to anthropologists in studying the evolution of bipedal gait. With step upward from monotremes to marsupials and placentals, there is a major change such that the entire coracoid plate has vanished, anterior coracoid has disappeared, and the coracoid has dwindled to a process like a crow's beak attached to lower margin of the scapula. The acromion is situated not at the front end of the bone but at the base of the spine. This marked change in pectoral girdle structure is related to the shift in limb posture in mammals as compared to reptiles and consequent changes in limb musculature.
| Subjects and Methods|| |
The study was conducted on 105 adult dry human scapulae of unknown age and sex.
In the present study, all the measurements were recorded in millimeters using a digital Vernier caliper. The following parameters were measured:
- Acromial length – From tip of the acromion to the acromial angle [Figure 1]
- Acromial width – From the midpoint of the lateral border of the acromion to the midpoint of the medial border of the acromion [Figure 2]
- Thickness of acromion process – Thickness was measured along the lateral border of the acromion at three points – at the anterior end of the acromion, at the middle of the acromion, and at the posterior end of the acromion. The average of these three measurements was considered as the thickness of the acromion process [Figure 3]
- Coracoacromial distance – From the lateral border of the coracoid process to the tip of the acromion [Figure 4]
- Acromioglenoid distance – From tip of the acromion to the supraglenoid tubercle [Figure 5].
|Figure 1: Dorsal view of the left scapula showing measurments of acromial length|
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|Figure 2: Dorsal view of the left scapula showing measurments of acromial width|
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|Figure 3: Demonstrating thickness of acromion process measured along the lateral border of the acromion|
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Data were tabulated. The mean and standard deviation for each parameter were calculated using SPSS version 16.0 (IBM, Chicago, USA). All damaged human scapulae were excluded from the present study.
| Results|| |
The mean and range of all acromial parameters are shown in [Table 1].
| Discussion|| |
Mansur et al. and Singh et al. found a much higher value of acromial length, whereas in the present study it was 41.65±7.57 mm, which was in accordance with the findings of Gupta et al. and Saha et al. Acromial width in the present study was 24.50 ± 2.91 mm, and it was in agreement with Gupta et al. [Table 2]. Nasr el-din WA et al. found a much larger acromial width, but his study was on the Egyptian population. The thickness of the acromion process in the current study was in accordance with Gupta et al. whose study was based on the South Indian population.
|Table 2: Comparison of mean values of acromial parameters in different populations|
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The impingement syndrome occurs against the anterior edge and undersurface of the anterior third of the acromion, coracoacromial ligament, and acromioclavicular joint rather than the lateral acromion. The posterior half of the acromion is not involved in the impingement process. Therefore, lateral acromionectomy or complete acromionectomy, which involves removal of the lateral edge without detachment of deltoid, is thought to weaken the deltoid unnecessarily. Due to this issue, removal of the anterior edge and undersurface of the anterior most part of the acromion process along with coracoacromial ligament was recommended which is named as anterior acromioplasty., Anterior acromioplasty has replaced these procedures for decompression of the rotator cuff from impingement. The significance of acromial parameters measured in the current study is important keeping in view acromioplasty which is the preferred operation these days for subacromial impingement syndrome.
Coracoacromial distance in the present study was 33.35 ± 6.12 mm. This parameter was highly variable in the previous studies. It was closest to the finding of Gupta et al. Coracoacromial distance signifies coracoacromial ligament length; therefore, it can be useful during resection of coracoacromial ligament, which provides significant pain relief in patients with impingement. The value of coracoacromial distance is much higher in the Nepalese population than the present study.
The mean acromioglenoid distance in the present study was 29.41 ± 4.65 mm. This parameter showed variable findings by all other previous authors. The distance of the coracoacromial arch from the supraglenoid tubercle <15 mm is associated with degenerative changes in the acromion process.
In the present study performed on 105 human scapulae, it was observed that our results were different from those of the Nepalese and Egyptian population,, while considering among the Indian population, our parameters were closer to the South Indian population.
Scrutiny of acromion process is important for comprehension of rotator cuff injuries and impingement syndrome. There are not many studies performed on morphometric analysis of the acromion process in the North Indian population to serve as a standard database; therefore, the data obtained in this study will augment to it.
| Conclusions|| |
The information procured in the present study will be of help to the orthopedic surgeons who need to know the relevant morphometry of the acromion process to plan surgeries such as acromioplasty, arthroscopic subacromial decompression, and in treatment of acromioclavicular arthritis. These parameters are also helpful in the analysis of acromial inclination by means of radiography and magnetic resonance imaging. These acromial parameters can be used in medicolegal investigations in identifying unknown human remains in cases of mass disaster and criminal investigations when a DNA test cannot be performed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2]