OSTEOMETRIC MORPHOMETRY OF PROXIMAL TIBIAL END IN INDIAN POPULATION: A FORENSIC POINT OF VIEW WITH ITS CLINICAL IMPORTANCE

Material and Method: This prospective descriptive study was carried out on 385 dry, adult tibias, which were collected from the department of Anatomy department of a medical college in north India. 385 fully ossified and processed dry bones were used to study. Unossified, injured or anomalous tibia bones were excluded from the study. Proximal end of tibia is studied under various parameters. After obtaining the values of the all parameters, data is corelated with the record section of the bone bank of the particular medical college. Result: It shows that, there is significant difference between male and female parameters and all results were statistically significant. Conclusion: This study will help to provide a basis for application in forensic science, in prosthesis, and in clinical practice also.


INTRODUCTION
Morphometry means the measurements of distances between pairs of anatomically homologous points, tangent points, and extremes of structures. It is the study of variations in measurements and correlations between theses such measurements (covariations). Morphometry is an important asset used in studies to understand the relationship of variables, such as age and sex, between organisms. Morphological and morphometric differences between males and females are studied and can be demonstrated through anatomic, biological, and physiological analyses.
Regarding the morphology of the skeleton, differences detected in the body structures can be essential to the determination of sex from the analysis of bones based on sexual dimorphism, which is clearly evidenced by the dimensions of bone structures [1,2]. Indeed, the identification of sex based on skeletal characteristics plays a crucial role in forensic medicine and anthropology [1].
Not all characteristics of the human skeleton serve as a reference for metric methods used to define sex in anthropological examinations or forensic investigations [3,4]. The bones most commonly used for this purpose are the mandible, skull, pelvis, long bone, and scapula. The skull and pelvis constitute the most often used and efficient sets of characters in morphological analyses and are extremely important to the identification of sex [5,6]. Long bones also play an important role in the evaluation of sexual dimorphism [7].
The tibia is a long bone that supports a large part of the body weight and is directly related to movements of the person. This bone also possesses strong dimorphic characteristics. The proximal portion of the tibia expands, forming a surface to support the body weight, the force of which is transmitted through the femur bone. The medial and lateral condyles, intercondylar area, and tibial tuberosity are located at this end of the tibia [8]. Morphometry is a reliable method for the evaluation of structures in this region of the tibia for medical purposes [9]. Morphometric variables are also important to forensic experts as a method for the identification of an individual based on his or her unique characteristics [10]. Considering the importance of sexual dimorphism to the identification of skeletons for scientific, medical, and forensic purposes, the aim of the present study was to investigate the gender of the person based on morphometric aspects of the proximal end of tibia in Indian population.

METHODS
This prospective descriptive study was carried out on 385 dry, adult tibias, which were collected from the department of Anatomy of a medical college in north India. 385 fully ossified and processed dry bones were used to study. Unossified, injured, or anomalous tibia bones were excluded from the study.
After obtaining the values of the all the parameters, data are correlated with the record section of the bone bank of the particular medical college. Table 1 shows the identification point of each parameter. Table 2 shows the minimum and maximum values of each parameter in both the genders. Table 3 shows the values of t-test and p value, which is highly significant in each parameter. Each parameter is higher in male in comparison with female parameter.

DISCUSSION
In the present study, the mean anteroposterior diameter of medial tibial condyle was observed as 41.72±5.89 in male and 38.02±4.52 in female, which shows clear statistical difference between male and female parameters. The results of our study are in consistent with the study conducted by the Osemeke et al., [11] who observed 4.77±0.46 cm in male and 4.06±0.48 cm in female. Transverse diameter (TD) of the tibial condyle was observed as 68.43±5.03 and 62.8±5.22 in male and female, respectively. A study conducted by Osemeke et al. observed the similar results, i.e., 7.61±0.73 and 7.74±0.67 for right and left tibia in men with a total of 7.68±0.69; in women, it was 6.73±0.60 and 6.84±0.63 for right and left with a total of 6.78±0.61. There was a statistically significant relation between values of men and women (p<0.05), but no significant side difference in both parameters. These findings are in agreement with the study conducted by the Gupta et al. [12] the study conducted by Ivan [13] found 6.62±0.51 and 6.66±0.56 for right and left TD of tibia condyle with a total mean value of 6.64±0.53. We observed the mean anteroposterior intercondylar length 46.22±4.61 and 39.74±4.6 in male and female respectively. Osemeke et al. [11]       also observed the similar results, i.e., AP length of medial and lateral tibia to be 5.08±0.33 and 4.72±0.33, respectively. A study conducted by [15], also observed the similar results, i.e., AP length of medial and lateral tibia condyle to be 4.80±0.31 and 3.98±0.29, respectively.
The findings from this osteometric study reveals sexual dimorphism in almost all parameters measured which is a perfect lead in the process of sex identification and consequently establishment of identity. Identification and detail study analysis for sex determination show a higher percentage of differences between males and females. More bones need to be identified with the identification point compared to demarking point in both the distal femur and proximal tibia. As the fact is that the overlapping range where sex could not be identified was small in the identification point analysis but larger in the demarking point analysis. This agrees with the study conducted by the previous authors on identification and demarking point analysis [14][15][16]. Both identification and demarking points for males were greater than those of females in the majority of parameters, which shows an indication of the usefulness of these parameters in sex determination.

CONCLUSION
Variability in geometry and anatomy of the knee exists irrespective of gender and human race is a well-known fact. This study establishes the morphometric attributes of proximal end of tibia in North Indian population and found sexual dimorphism in all parameters of the proximal tibia measured. The bones which were sexed using demarking points were however of greater degree of certainty than those sexed using identification points and it is not always necessary for all parameters to cross the demarking points for sex identification. The difference in proximal tibia anatomy between genders provides a biological profiling system for sex identity and would add to the design of knee prostheses for the North Indian population where perfect precision is required. This study will help to provide a basis for the application in forensic science, in prosthesis, and in clinical practice also.