Gender Determination Using Anthropometric Parameters of Metacarpals and Phalanges on Hand Radiographs

 

Horathal Pedi Gedara Dinusha Udayangani1, Bimali Sanjeevani Weerakoon1*

1Department of Radiography/ Radiotherapy, Faculty of Allied Health Sciences, University of Peradeniya, Peradeniya, 20400, Sri Lanka.

 

*Email: [email protected]


ABSTRACT

Gender determination in a living human being based on the skeleton system remains a challenge obviously because a human skeletal does not show a consistent or gradual growth rate. The purpose of this study was to assess the accuracy of gender determination from the linear measurments of metacarpals and phalanges using hand radiographs. A retrospective, quantitative study was conducted and computed and digital hand posterior-anterior radiographs were taken using the standardized imaging protocol (total=80, male=40, female=40). The linear measurements of metacarpals and the proximal, middle and distal phalanges were obtained. The results showed that males having significantly larger metacarpals and phalanges than females (p< 0.05). The Standardized Canonical Discriminant Function Coefficients were reported as M4=.659, MP3 = .394, DP3 = .328, M1 = .267, PP3 = .258, DP4 = .176, M3 = .105, PP1 = .103, PP4 = .089, DP2 = .077, M2 = .054, and MP1 = .045.  It can be concluded that linear measurements of each metacarpal and the proximal, middle and distal phalanges of the right hand can be used to distinguish the gender of individuals of the Sri Lankan population. Further, linear measurments of the 4th metacarpal from hand PA radiographs can be highly contributed to predicting the gender while MP3 and DP3 follow the significant contribution. Further studies are recommended with a larger sample to confirm the results.

Key words: Radiographs, Gender, Metacarpals, Phalanges, Linear measurements


INTRODUCTION

Determining gender, age, and stature of living or dead human beings are currently a mandatory element in many aspects. Mostly in forensic medicine, it has been given much information regarding the determination of gender and age by using several methods and based on many sources [1]. But it is also crucial to make attention to living human beings by stressing many aspects as well. Especially gender and age estimation in a living human being based on the skeleton system remains a challenge obviously because a human being’s skeletal does not show a consistent or gradual growth rate. Many studies have been done related to gender and age estimation in selected skeletal human beings by using x-ray images [2].

The skeletal system can be well diagnosed by using x-ray imaging modalities such as conventional radiography, computed radiography (CR), digital radiography (DR), and Computed Tomography. Since plain radiography was involved as the primary imaging diagnostic modality, hand posterior-anterior (PA) x-ray radiographs have been frequently studied projection which leads to diagnosing many diseases such as injuries, rheumatoid arthritis, infections, and tendons ligament damage. Each hand consists of mainly three categories of bones (phalanges, metacarpals, and carpals) that all together give support and flexibility to soft tissue to make movements of the hand. Phalanges are the bones that make up the fingers of the hand and toes of the foot as well. Each hand consists of 14 phalanges; hence all are 56 phalanges in the human body. Even though each finger builds up with three phalanges, the thumb has only two phalanges That metacarpus is classified as a type of long bone even though they seem small because; each metacarpal bone consists of a distal head, shaft, and proximal base. Proximally each bone articulates with carpal bones while distally, it articulates with proximal relevant phalange [3].

The human hand shows differences in proportion between males and females due to hormonal changes. Several studies have measured the phalanges and the metacarpal's lengths to determine or estimate any differences based on different variables [2, 4-11]. Some studies have concluded that the lengths of phalanges and metacarpals can be used as a tool for gender determination. Alcioglue et al. observed that a better gender determination could be found through the use of the length of the phalanges for the Turkish population [7]. In a gender determination study done by Kondo et al. in the modern Japanese population, it was found that males had longer 4th fingers but shorter 2nd fingers than females [10].

Both CR and DR show higher image quality and many post-processing techniques, giving better diagnostic power than conventional plain radiography imaging [12]. One of the main advantages of CR and DR imaging modalities over conventional radiography is that both CR and DR x-ray radiographs can be archived by using Digital Image Communication in Medicine (DICOM). It is a standard procedure for communicating and managing medical imaging information and data related to medical images in many healthcare facilities [13]. DICOM was developed by the American college of radiology (ACR) AND the National Electrical Manufacturers Association (NEMA) [13, 14]. DICOM standard is mainly used to produce, store, share, display, send, query, process, retrieve, and print medical images. Picture Archiving and communication system (PACS) is a medical imaging technology that uses DICOM to store and transmit medical images. PACS eliminates problems related to manual storage and file sharing. Many other advantages come with post-processing techniques in CR and DR imaging modalities that can be facilitated to diagnose even subtle changes on radiographs [14].

Many countries have successfully evaluated the length of metacarpals and phalanges variation according to age as well as gender. However there is no evidence of gender determinations using the metacarpals and phalanges of hand based on the Sri Lankan population. Therefore, this study would be the first step in assessing the gender based on the linear measurments of metacarpals and phalanges by using hand radiographs in a cohort of Sri Lankan population. 

MATERIALS AND METHODS

This was designed as a retrospective, quantitative study based CR and DR hand PA radiographs which were performed from 1st February 2021 to 1st November 2021.

After receiving ethical clearance from the Faculty of Allied Health Sciences (reference number: AHS/ERC/2021/050) all radiographs were obtained from the Department of Radiology, Teaching Hospital, Peradeniya. Eighty hand radiographs (encompassing 40 women and men) that were obtained by using CR and DR imaging acquisition modalities were included as the study population. All the radiographs were taken using the standardized imaging protocol (Focus Receptor Distance =100cmwith the vertical central X-ray beam perpendicular to the receptor). The radiographs that show little or lack of skeletal trauma and/or abnormalities in the phalanges and metacarpals were encompassed in the study. To ensure normal bone study, history of bone tumors or arthritis, significant fractures, pathological lesions such as congenital and development dysplasia, metabolic bone illnesses, connective tissue diseases, and earlier orthopedic surgery were excluded from the study. Further, radiographs with unidentified age and gender details and repeat examinations were excluded from the study.

Linear measurements of the metacarpals (M), proximal phalanges(PP), middle phalanges(MP), and distal phalanges(DP) of the right hand were obtained using MicroDicom Viewer (Version 3.1.4), from the CR and DR DICOM radiographs under the same light condition. All selected radiographs were classified into two groups according to gender.

All radiographs were displayed 100% and, the edges of bones were confirmed by zooming further. The gender of the patients was identified from the DICOM tags. Then the following measurements were made on all five metacarpals and phalanges separately: the length 1) from the mid-point of the base to the mid-point of the head of the metacarpals; 2) from the mid-point of their bases to the mid-point of their apices of proximal, middle, distal phalanges.

The data were analyzed using SPSS (version 27.0). Before subjecting the data to statistical analyses, descriptive statistics (mean and standard deviation) were calculated and assessed for the normality. The data was not normally distributed. Therefore, Mann-Whitney Test was applied to compare the length differences between the male and female groups. The confidence level was set at 95% and a p-value less than 0.05 was taken to be substantial. Direct discriminant function analysis was conducted to identify the gender discriminatory capabilities of the linear measurements obtained (Figure 1).

 

Figure 1. Measuring parameters on hand radiographs. Detailed information is discussed in table 1.

 

 

Table 1. Measuring parameters.

M1: 1st Metacarpal

PP1:1st Proximal phalange

MP1:1st Middle phalange

DP1:1st Distal phalange

M2: 2nd Metacarpal

PP2:2nd Proximal phalange

MP2:2nd Middle phalange

DP2:2nd Distal phalange

M3: 3rd Metacarpal

PP3:3rd proximal phalange

MP3:3rd Middle phalange

DP3:3rd Distal phalange

M4: 4th Metacarpal

PP4:4th Proximal phalange

MP4:4th Middle phalange

DP4:4th Distal phalange

M5: 5th Metacarpal

PP5:5th Proximal phalange

MP5:5th Middle phalange

 

RESULTS AND DISCUSSION

 

The descriptive statistics  of linear measurements of Ms, PPs, MPs, and DPs for both male and female groups  are presented in Table 2. The Wilk’s Lambda (l) test of mean difference is displayed in Table 2.

The results showed that all the metacarpals (M1 [l= .606, P=.000], M2 [l=.564, P=.000], M3[l=.51, P=.000], M4[l=.521, P=.000], M5[l=.874, P=.001]), proximal phalanges (PP1[l=.734, P=.000], PP2[l=.866, P=.001], PP3[l=.705, P=.000], PP4[l=.699, P=.000], PP5[l=.882, P=.002]), middle phalanges (MP1[l=.808, P=.000], MP2[l=.903, P=.005], MP3[l=.831, P=.000], MP4[l.843, P=.000], MP5[l=.936, P=.024]) and distal phalanges (DP1[l=.888, P=.002], DP2[l=.830, P=.000], DP3[l=.821, P=.000], DP4[l=.875, P=.001]) were significantly larger (p < 0.05) in males than  females.

Table 2. Mean linear dimension of phalanges based on gender

Descriptive

Gender

( Male:40, Female:40)

Mean(mm)

SD

M1

Male

46.721

2.778

Female

42.776

2.129

M2

Male

69.591

4.216

Female

63.481

2.636

M3

Male

66.495

3.925

Female

60.037

2.738

M4

Male

58.32

3.458

Female

47.046

1.980

M5

Male

52.033

7.428

Female

47.046

5.805

PP1

Male

30.313

2.263

Female

28.087

1.3763

PP2

Male

39.770

5.3437

Female

36.644

1.9402

PP3

Male

43.904

2.7134

Female

40.993

1.7354

PP4

Male

40.995

2.3991

Female

37.870

2.4249

PP5

Male

32.323

3.3049

Female

30.087

2.872

MP1

Male

22.687

2.3783

Female

20.533

2.0948

MP2

Male

22.311

1.8526

Female

21.119

1.8202

MP3

Male

26.879

1.7898

Female

25.342

1.6622

MP4

Male

25.638

1.8243

Female

24.182

1.5867

MP5

Male

17.854

1.6600

Female

17.106

1.2069

DP1

Male

16.336

1.448

Female

15.331

1.4138

DP2

Male

17.447

1.2989

Female

16.272

1.3318

DP3

Male

17.792

1.3758

Female

16.604

1.1913

DP4

Male

15.917

1.3566

Female

14.865

1.4558

 

Wilk’s Lambda tests in this studyassess the ability of the variables (M, PP, MP, and DP) included in the model to make substantial estimates about thegender. The Canonical Correlation reflects the relationship between Discriminant Function and gender and in this study it is 0.763 (Table 4). As demomstrated in Table 4, in the test of function, the value of the significance test associated with the Canonical Correlation is p < 0.05. Therefore in this study, the Discriminant Function plays a significant role in terms of accounting for differences between gender groups.

Table 3. Wilk’s Lambda test of mean differences

 

Wilks' Lambda

F

Sig.

M1

.606

50.808

.000

M2

.564

60.375

.000

M3

.517

72.842

.000

M4

.521

71.626

.000

M5

.874

11.194

.001

PP1

.734

28.277

.000

PP2

.866

12.092

.001

PP3

.705

32.663

.000

PP4

.699

33.590

.000

PP5

.882

10.434

.002

MP1

.808

18.485

.000

MP2

.903

8.425

.005

MP3

.831

15.821

.000

MP4

.843

14.515

.000

MP5

.936

5.310

.024

DP1

.888

9.874

.002

DP2

.830

15.957

.000

DP3

.821

17.001

.000

DP4

.875

11.179

.001

 

Table 5 presents Standardized Canonical Discriminant Function Coefficients. These coefficients reflect the relative contributions of the variables (linear measurments of M, PP, MP, and DP) to the Discriminant Function.  All variables that reported Standardized Canonical Discriminant Function Coefficients greater than the value of 0.3 are considered to contribute substantially to the Discriminant Function. As demonstrated in Table 5, the lengths of M4=.659, MP3 = .394 and DP3 = .328 contribute substantially to the Discriminant Function. Further, it can be observed that the length of M4 contributes to group separation more than other variables in this study, as it reported a higher Standardized Canonical Discriminant Function Coefficient of 0.659. MP5 demonstrated the least contribution to group separation giving a Standardized Canonical Discriminant Function Coefficient of 0.042.

Table 4. Summary of  Canonical Correlation  Discriminant Function

Eigenvalues

Function

Eigenvalue

% of Variance

Cumulative %

Canonical Correlation

1

1.390a

100.0

100.0

.763

Wilks' Lambda

Test of Function(s)

Wilks' Lambda

Chi-square

df

Sig.

1

.418

59.670

19

.000

 

 

Table 5. Standardized Canonical Discriminant Function Coefficients

 

Function

1

M1

.267

M2

.054

M3

.105

M4

.659

M5

-.179

PP1

.103

PP2

-.050

PP3

.258

PP4

.089

PP5

-.052

MP1

.045

MP2

-.275

MP3

.394

MP4

-.587

MP5

-.042

DP1

-.279

DP2

.077

DP3

.328

DP4

.176

Since the determination of gender assists in concluding the identity of an individual, it has remained an essential fact. Anthropometric measurements of the hand are beneficial factors in gender identification as shown in this research.

In this study the second metacarpal (index finger) bones of the right hand showed a higher mean value in both genders. Further, males have substantially longer metacarpals and distal, middle and proximal phalanges than females. These results are similar with the study done by Kondo et al. on a Japanese population [10] DP4). A study done on “Nigerian population” found that all the metacarpals and three proximal phalanges of the right hand provided dimensional differences in sex, which is slightly different from what was observed in this study [2]. The study done on on Egyptian population discovered that the measurements of the metacarpals and phalanges can be used in gender determination [1]. From these results, it is clear that the ability to discriminate between sexes based on hand measurements varied between populations and it is population specific. According to the present study linear measurements of the 4th metacarpal from hand PA radiographs can be highly contributed to predicting the gender while MP4, MP3 and DP3, follow the considerable contribution for Sri Lankan population.

 

CONCLUSION

This study showed that males have greater metacarpals and phalanges lengths than females. Further, it also indicates that the linear measurements for each metacarpal and proximal, middle and distal phalanges of the right hand can be used for discriminating the gender of the individuals. The linear measurments of the 4th metacarpal from hand PA radiographs can be highly contributed to predicting the gender while MP3 and DP3 follow the significant contribution. To beast of our knowledge, this is the first study determining gender by linear measurments of metacarpals and phalanges on hand radiographs in Sri Lankan population. Further studies are recommended with a larger sample to confirm the results.

ACKNOWLEDGMENTS : We would like to express our deep and sincere gratitude to the Radiographer-In charge and all radiographers at Teaching Hospital-Peradeniya, who allowed me to collect the sample for this study.

CONFLICT OF INTEREST : None

FINANCIAL SUPPORT : None

ETHICS STATEMENT : Ethical clearance was obtained from the Ethics Review Committee (ERC) of the Faculty of Allied Health Sciences, University of Peradeniya (Ethical clearance with reference number: AHS/ERC/2021/050).

References

1.       Abdelaal GM, Abdallah EA, Alshamy AA, Megahed EE. Adult Sex Discrimination Using Metric Measurements of Hand Digital Radiographs in Egyptian Population. Forensic Med Anat Res. 2022;10(2):27-43. doi:10.4236/fmar.2022.102004.

2.       Alabi AS, Aigbogun Jr EO, Lemuel AM, Buhari MB. Sex estimation from radiogrametric linear dimensions of the metacarpals and phalanges in a Nigerian population. Forensic Sci Int. 2020;2:100097. doi:10.1016/j.fsir.2020.100097.

3.       Barrett K, Barman S, Yuan J, Brooks H. Ganong’s Review of Medical Physiology. 26th ed. McGraw Hill / Medical; 2019.

4.       Karaman AG, Teke HY, Günay I, Dogan B, Bilge Y. Height estimation using anthropometric measurements on X-rays of wrist and metacarpal bones. Internet J Biol Anthropol. 2008;2(1):1-22. doi:10.5580/627.

5.       Al-Fartusie FS, Majid M, Zageer DS. Sex determination from hand dimensions and digital distal phalanx measurements to the iraqi population residing in Baghdad. Int J Med Toxicol Leg Med. 2020;23(3and4):333-43. doi:10.5958/0974-4614.2020.00084.4.

6.       Rad AH, Mohammadi S, Babahajian A, Yousefinejad V. Sex determination based on dimensions of wrist and metacarpals in contemporary Iranian population. Forensic Imaging. 2021;26:200464. doi:10.1016/J.FRI.2021.200464.

7.       Alicioğlu B, Yilmaz A, Karakaş HM, Cigali BS, Çikmaz S, Uluçam E. Sex determination by the interarticular distance of metacarpals and phalanges: a digital radiologic study in contemporary Turkish people. Anatomy. 2009;3(1):14-20. doi:10.2399/ana.08.027.

8.       Zaher JF, El-Ameen NF, Seedhom AE. Stature estimation using anthropometric measurements from computed tomography of metacarpal bones among Egyptian population. Egypt J Forensic Sci. 2011;1(2):103-8. doi:10.1016/j.ejfs.2011.03.002.

9.       Ozsoy T, Oner Z, Oner S. An attempt to gender determine with phalanx length and the ratio of phalanxes to whole phalanx length in direct hand radiography. Medicine. 2019;8(3):692-7. doi:10.5455/medscience.2019.08.9074.

10.    Kondo M, Ogihara N, Shinoda Ki SA, Kohta I. Sexual dimorphism in the human hand proportion: A radiographic study. Bull Natl Mus Nat Sci. 2017;43:1-6.

11.    Ernsten L, Körner LM, Heil M, Richards G, Schaal NK. Investigating the reliability and sex differences of digit lengths, ratios, and hand measures in infants. Sci Rep. 2021;11(1):1-4. doi:10.1038/s41598-021-89590-w.

12.    Whitley AS, Jefferson G, Holmes K, Sloane C, Anderson C, Hoadley G. Clark's Positioning in Radiography 13E. crc Press; 2015.

13.    Gibaud B. The DICOM standard: a brief overview. Mol Imaging. 2008:229-38. doi:10.1007/978-1-4020-8752-3-13.

Bidgood Jr WD, Horii SC, Prior FW, Van Syckle DE. Understanding and using DICOM, the data interchange standard for biomedical imaging. J Am Med Inform Assoc. 1997;4(3):199-212. doi:10.1136/jamia.1997.0040199.