|Year : 2020 | Volume
| Issue : 1 | Page : 88-90
Morphometry of neck-shaft angle in dried femora of the central Indian population and its clinical implications
Jagriti Agrawal1, Diwakar Dhurandhar1, Tripti Chandrakar2
1 Department of Anatomy, Pt. J.N.M Medical College, Raipur, Chhattisgarh, India
2 Department of Community Medicine, Pt. J.N.M Medical College, Raipur, Chhattisgarh, India
|Date of Submission||28-Jul-2019|
|Date of Decision||30-Oct-2019|
|Date of Acceptance||10-Nov-2019|
|Date of Web Publication||13-Oct-2020|
Dr. Diwakar Dhurandhar
Department of Anatomy, Pt. J.N.M Medical College, Raipur, Chhattisgarh - 492 001
Source of Support: None, Conflict of Interest: None
Introduction: The neck-shaft angle (NSA) is the angle formed by the neck axis and the long axis of the femur. Knowledge of this angle facilitates the preoperative planning of osteotomy, arthroplasty, or fracture fixation. It also helps in designing suitable implants with more accurate angulations of the femur neck. Hence, the present study aimed at giving ready reference data to clinicians of the femoral NSA in the Central Indian population. Materials and Methods: A total of 153 dried femora, 78 of the right side and 75 of the left side of unknown sex and age were obtained from the Department of Anatomy, Pt. J. N. M Medical College, Raipur. NSAs were measures and statistically correlated with laterality using “Independent t-test,” P value was obtained. Results: Mean NSA of right-sided femora was 133.88°C ± 15.04°C (range from 103°C to 160°C) and of left-sided femora was 132.81°C ± 15.81°C (Range from 106°C to 160°C). No significant difference in values of NSA was found in the right and left-sided femora. Conclusion: The outcome of this study can be used as a ready reference data by orthopedicians, physiotherapists, and prosthesis designers for the central Indian population. Knowledge of normal value would also be helpful in making the clinical diagnosis of femur neck fractures and coxa vera.
Keywords: Central Indian population, femur, femur neck fracture, neck-shaft angle
|How to cite this article:|
Agrawal J, Dhurandhar D, Chandrakar T. Morphometry of neck-shaft angle in dried femora of the central Indian population and its clinical implications. J Datta Meghe Inst Med Sci Univ 2020;15:88-90
| Introduction|| |
The femoral neck-shaft angle (NSA) is the angle formed by the neck axis and the long axis of the femur. The neck axis is the line drawn from the center of the femoral head to the center of the femoral neck at the narrowest part of the neck. The long axis of the femur is defined as the line drawn from the middle of the femoral condyles to the middle of the greater trochanter in two planes. The mean NSA in adults is 135°C and ranges from 125° to 132° as quoted in various standard textbooks of anatomy and orthopedics., There is physiological valgus in infancy after which there is progressive decrease in the angle with no change after attainment of full growth. The normal range of NSA has been deduced by data obtained from the population of Western countries. Furthermore, there is a wide variation in femoral NSA observed with race, gender, side, and age. The NSA is one of the main diagnostic criterions that clinicians use to detect the probability of femoral neck fracture in a subject as coxa valga (More than 140°C NSA) is associated with a femoral neck fracture. NSA is important in the preoperative planning of osteotomy, arthroplasty, or fracture fixation. It also helps in designing suitable implants with more accurate angulations of the femur neck. Racial variations in anthropometric parameters exist because of genetic and various socio-cultural practices. Peoples involved in greater walking or physical work are more likely to have higher NSA. Since the data on the morphometry of femoral NSA on dry adult femora in central Indian population are less, the present study was undertaken with the following objectives[Figure 1]:
|Figure 1: Photograph showing the method to assess femur neck-shaft angle using goniometry of dried bones. Neck-shaft angle is the angle between the neck axis and the long axis of the femur|
Click here to view
- To compile a database of normal femoral NSA in healthy adults among the central Indian population
- To statistically examine if femoral NSA was significantly associated with laterality of the bone.
| Materials and Methods|| |
A total of 153 dry femora of unknown age and sex available in the anatomy department were studied, of which 78 belonged to the right side and 75 to the left side. All adult dry femora without any external abnormality were included in the study, whereas femora having any gross deformities or damage were excluded from the study. The measurement of NSA was done by a goniometer on dried femora which is considered the most accurate method to assess the morphometry of a bone. The measurement of NSA was taken twice by an observer to rule out intra-observer bias. The measurement once taken by an observer was repeated by other authors to negate any inter-observer variations. The mean NSA of left femora was compared with that of right femora by applying independent “t”-test. P < 0.05 was considered statistically significant. Data were entered into MS Excel spreadsheet. Descriptive and analytical interpretation of the data was done by the SPSS version 20.0 (Chicago, Illinois, USA).
Ethical clearance was obtained from the Institutional Ethical Committee of JNM, Medical College, Raipur, Chhatisgarh on 5th Nov 2019. With ethical clearance no JNM/EC/2019-20/45.
| Results|| |
After excluding the deformed and damaged femora, the total number of femora procured was 153. Seventy-eight were of the right side and 75 were of the left side. As shown in [Table 1], the mean value of NSA of left femora was 133.88 ± 15.05, whereas that of the right side was 132.81 ± 15.81. No statistically significant difference (P = 0.668) was observed when mean NSA of right femora was compared with that of left femora using independent “t”-test.
| Discussion|| |
NSA assumes huge clinical significance as it is known to be associated with various pathologies. Genu varum is known to be associated with coxa valga (NSA >140) leading to early degeneration of medial compartment of the knee; whereas coxa vara (NSA <120) can have congenital, metabolic (Paget's disease), neglected trauma, and developmental (osteogenesis imperfecta) or postperthes as its etiology.
Various methods have been suggested to evaluate NSA such as X-rays, Computed tomography, magnetic resonance imaging, and dried bone measurements. As goniometer for measuring the NSA of dried femora is considered as the best available tool and requires little infrastructure, hence it was preferred modality for use in the present study.
Comparison of the findings of the present study was compared with those of previous foreign and Indian literatures are shown in [Table 2] and [Table 3], respectively. The difference in the values of NSA found in the present study was due to the different study populations as well as the different methods employed for the assessment of NSA. The mean NSA found in the present study can be used as a baseline ready reference data for designing appropriate prosthesis tailor made for the central Indian population as there are wide variations in the values of NSA among different populations as found in previous studies.
| Conclusion|| |
Previous literatures have reported significantly more NSA of left-sided femur than right-sided which could be due to particular limb dominance., The present study found no significant relation of mean femur NSA with laterality.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]