European Journal of Cardiovascular Medicine

The femur or thigh bone is the longest and strongest bone and is about 45 cm (18 inches) long and about one fourth of the height of the individual [1]. It has a proximal rounded, articular head projecting medially from its short neck, greater and lesser trochanters. The distal extremity is wider and more substantial, and presents a double condyle that articulates with the tibia[2].The mobility of hip joint is facilitated by the angle, obliquity of the femur within the thigh, and help the knee to be adjacent and inferior to trunk, enabling limb to swing clear of the pelvis [3,4]. The neck shaft angle decreases significantly because of the change in body portion and adaptation of the hip joint to vertical posture [5]. The femur neck shaft angle is widest at birth and diminishes gradually until the age of 10 year [6]. Morphometric study of the upper end of femur (Parameters like neck- shaft angle, transvere and vertical diameters of head) is important in fracture management to acknowledge the information about patterns of fractures , classification systems, and treatment procedures.

50 dry human femora of unknown sex were collected from Department of Anatomy, Kurnool Medical College, Kurnool and different Medical Institutions. The major sex determinative parameters like Vertical diameter of the head of femur, Transverse diameter of the head of femur, and neck-shaft angle of femur were measured.

1.      Vertical Diameter Of The Head Of Femur

It was measured by the straight distance between the highest and deepest points of the head using sliding calipers [Figure 1].

2.      Transverse Diameter Of The Head Of Femur

 It was measured by the straight distance between the most laterally projected points on the equatorial plane taken at right angle to the vertical diameter by using sliding calipers [Figure 2]

3.      Neck Shaft Angle Of Femur

It is the angle made by axis of shaft with the axis of the upper anterior column. Axis of column is determined by means of a thread which divides the anterior surface of the column in two halves. Axis of the shaft is determined by a thread which extends in the mid sagittal plane over the anterior surface of the bone from the upper end of the oblique line of the condyles by using thread [Figure 3]. All the measurements were statistically analyzed and tabulated.

The vertical diameter of head of femur ranges from a minimum 38.50 mm to maximum 54 mm with a mean value of 44.96 mm. The transverse diameter of head of femur varies from a minimum 32 mm to maximum 53mm with a mean value of 44mm and the Neck shaft angle ranges from a minimum of 115⁰ to maximum of 150⁰ with a mean value of 134.70⁰ were noted(Table 1).

Table -1: Descriptive Statistics

Figure 1: Measuring vertical diameter of head  of femur by using sliding callipers

.

The range of known sex compared with vertical diameter of head of the femur, 21 out of 50 identified as belonging to male and 29 to female, and compared to the range of known sex with transverse diameter of the head of the femur was 23 femora out of 50 identified as belonging to male and 27 to female, and the range of known sex in reference to neck-shaft angle of femur, 22 femora out of 50 could be identified as belonging to male and 28 to female. The neck shaft angle of femur showing higher percentage of accuracy in sexing of the femur in our study (Table 2).

Table-2: Sexing of femur by individual parameters

Figure 2: Measuring Transverse diameter of head of femur by using sliding callipers

Figure 3: Measuring Neck –shaft angle of femur by using thread as two axial columns

Vertical diameter of head of femur showed higher percentage of accuracy in sexing the femur in the present study (7). The vertical diameter of head as one of the sex categories for the femur. The mean head diameter of male femur was significantly greater than the mean head diameter of female femur (8). The maximum head diameter alone could correctly assign sex to 92.5% of males and 95.5%. The head vertical diameter of right femur was significantly greater than left femur.(9,10,11).Transverse diameter of head of femur showed higher percentage of accuracy for sexing the femur(9).There was no significant difference between Right and Left femora (Rt= 44.7, Lt= 44.3). There was enormous sexual difference in male and female head of femur, the results are of great applied and practical value in referred specimen in medico legal field( 9,12). There was no significant statistical bilateral difference found in bones (13,14,15). In male femur, mean transverse diameter is 86.29 mm and in female femur, mean transverse diameter is 74.45mm. The  diameter of head of femur  in our study independently could be used for determining sex of head of femur with high significant results(15). The neck shaft angle has been reported an average of 126⁰. The neck shaft angle ranges from 120⁰- 136⁰ with a mean of 126.70⁰(16). The estimated defective angle can be of help for forensic identification of an individual with pathological changes leading to an abnormal gait(17). The neck shaft angle was bigger in females (18,19) and some authors reported the angle was  bigger in males (20,21,22). The neck shaft angle of left femora were generally shown to have greater value, but they were not significantly greater than the corresponding dimensions of right femur (12). The values of vertical diameter of head, Neck shaft angle and Transverse diameter of head showed 75- 80% percentage of accuracy of determining the sex of femur in the present study. The results of the present study are in agreement with previous literature and considered as significant variables in sex determination (12,13,18,21).

The femora of unknown gender can be sexed to extend of 75- 80 % with parameters like vertical and transverse diameters of the head of the femur, Neck- shaft angle of femur and these parameters considered as significant variables in sex determination and also play a crucial role to  help the orthopaedic surgeons while planning surgeries.

Acknowledgements

The authors are also grateful to authors, editors and publishers of all those articles, journals and books from where the literature for this article has been reviewed and discussed.

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