European Journal of Cardiovascular Medicine

The femur is the largest and strongest bone in the body, and the structure of its proximal portion allows the leg to move in three dimensions relative to the torso, thus serving as a linchpin of human mobility. The prevalence of hip joint pathologies, including osteoarthritis, femoral neck fractures, and other degenerative conditions, continues to rise, necessitating effective surgical interventions such as total hip arthroplasty (THA) as a definitive treatment. The proximal femur plays a pivotal role in weight-bearing, facilitating lower limb movement, and serving as an attachment site for crucial musculature [1]. Given its biomechanical significance, understanding its morphometry is essential for optimizing surgical outcomes in THA. Bone morphology is influenced by a multitude of factors, including race, sex, environmental conditions, and lifestyle. Notably, Nurzenski et al. demonstrated that lifestyle factors significantly impact geometric indices of bone strength in the proximal femur, further emphasizing the need for population-specific anatomical studies [2]. In THA, achieving proper femoral offset (FHO) and vertical offset (VO) is critical for restoring range of motion and abductor muscle function postoperatively [3]. However, most commercially available hip prostheses are designed based on anatomical data derived from European populations [4,5], which may not be universally applicable. Mismatched implant sizes—whether undersized or oversized—can compromise joint stability, biomechanics, and long-term functional outcomes. The primary goal of surgical management in hip disorders is anatomical reduction with stable fixation to promote bone healing and early mobilization. A precise contour fit between the bone and implant is crucial for establishing a robust bone-implant construct, thereby enhancing fixation strength and reducing complications [6]. Previous morphometric studies of the proximal femur across diverse populations have revealed significant regional and sociodemographic variations [7], underscoring the importance of population-specific implant design. Accurate measurement techniques are fundamental in morphometric studies. While traditional methods involve direct caliper measurements, discrepancies have been observed when compared to digital software-based assessments [8]. In the present study, we employed both direct measurements of dry bones and digital photographic analysis to enhance precision. This approach aligns with Unnanuntana et al.'s (2009) findings, which demonstrated that digital photography improves accuracy over radiographs and manual measurements by ensuring consistent landmark identification and reproducibility [9-11]. By analyzing proximal femoral morphometry through these methods, this study aims to contribute valuable anatomical data that can aid in the design of better-fitting implants, optimize surgical techniques, and ultimately improve THA outcomes in our population.

Aim and Objectives: This study aimed to conduct a morphometric analysis of the proximal femur that belonged to the East Indian population and investigate its clinical significance in total hip arthroplasty.

In this cross-sectional study, 50 adult dry femur bones (among which 25 belong to the right side and 25 belong to the left side) of unknown gender and age were studied in the Department of Anatomy, Indira Gandhi Institute of Medical Sciences, Patna, Bihar (India). 

Inclusion criteria:

·         Femur bone with the intact upper end: Only well-preserved bones that were suitable for accurate morphometric measurements were taken.

·         Age and Sex:

Ø  Bones from adult individuals of various age groups were included.

Ø  Both male and female bones were considered.

·         Specimen Quality:

Ø  Bones that were free from significant deformities, fractures, or pathological conditions affecting the proximal femur were taken.

Proper handling and care were exercised to maintain the integrity of the specimens throughout the study.

Exclusion criteria:

·         Severely Damaged or Fragmented Bones:

Ø  Bones that were extensively damaged, fragmented, or showed significant deformities affecting the proximal femur.

·         Pathological Conditions:

Ø  Bones exhibiting pathological conditions such as tumors, infections, or systemic diseases affecting the proximal femur.

Ø  Bones with evidence of previous surgical interventions or orthopedic procedures that may alter the natural morphology of the proximal femur.

·         Non-human Specimens:

Ø  Exclusion of non-human bones or specimens from the study.

Morphometric parameters of the upper end of the femur were measured manually by using anthropometric instruments like a ruler, goniometer, and digital calliper. The following parameters were observed:

·         Femoral length (FML): It was measured as the distance between the highest points of the femur head to the lowest point of the medial condyle was measured as the femur length [Figure 1].

·         Femoral Head Diameter (FHD): It was measured as the distance in a straight line between the upper ends to the lower end of the femoral head in the cranio-caudal axis [Figure 2].

·         Femoral Neck Length (FNL): It was measured as the distance between the inferior region of the base of the femoral head and the lower end of the intertrochanteric line [Figure 3].

·         Femoral Neck Thickness (FNT): It was measured as the thickness of the neck of the femur in the anteroposterior axis [Figure 4].

·         Femoral Neck Diameter (FND):  It was measured as was the distance in a straight line from the upper end to the lower end of the anatomical neck of the femur in craniocaudal direction [Figure 5].

·         Cervico Diaphyseal Angle (CDA): It was measured as the angle between the line joining the center of the head of the femur and the midpoint of the Intertrochantric line (Femur Neck Axis) and the vertical line from the tip of the greater trochanter (Femur Shaft Axis) [Figure 6].

Linear measurements were taken with the help of a digital vernier caliper, which had a sensitivity of 0.01 mm, and the least count observed was 0.01 mm. Measurements were taken twice, and the average was included in the analysis. The obtained data is expressed in terms of Mean and standard deviation. A p-value less than 0.05 was considered significant in this study for the analysis. The findings were tabulated and analyzed statistically by using the GraphPad Prism version 9 software.

The comparison of morphometric parameters between the right and left sides of the proximal femur showed that the mean femoral length was 42.65 ± 2.57 cm on the right and 42.48 ± 3.02 cm on the left (p = 0.764), indicating no significant difference. The femoral head diameter measured 42.32 ± 2.94 mm on the right and 42.01 ± 3.58 mm on the left (p = 0.525), while the femoral neck length was 44.64 ± 8.02 mm on the right and 44.27 ± 5.96 mm on the left (p = 0.908), both showing no statistically significant variation. Similarly, the femoral neck thickness was 22.81 ± 2.08 mm on the right and 23.92 ± 2.96 mm on the left (p = 0.598), with no significant side-to-side difference. However, the femoral neck diameter was significantly larger on the right (34.12 ± 3.78 mm) compared to the left (31.46 ± 3.21 mm; p = 0.007). Additionally, the cervicodiaphyseal angle was significantly more obtuse on the left side (130.41 ± 3.12°) than on the right (127.24 ± 4.38°; p = 0.002) (Table 1).

Table 1: Showing different parameters of the femur.

Annually, around 80,000 artificial hip joint replacements are performed globally [12]. Prostheses should be tailored to the unique population due to regional variations in human stature. Reddy et al. emphasized that an incongruence between the femoral bone and stem may unequivocally cause micromotion, potentially resulting in thigh discomfort, osteolysis, and aseptic loosening [13]. If the implant is very large, it may result in a fracture of the femur; hence, the inclination is to select a smaller size for safety. However, an inadequately sized implant may not achieve proper osseointegration with the bone [14].  Mahaisavariya B et al. integrated CT imaging with reverse engineering to acquire and analyze the three-dimensional inner and outer geometry of the proximal cadaveric femur [7]. Deshmukh TR et al. examined the femoral geometry in the Vidarbha region of India utilizing a mathematical methodology [15]. The anthropometric measurements and values derived from mathematical models showed a strong association. Siwach RC and Dahiya S conducted a comparative analysis of femoral parameters between Indian cadavers and those from Western, Chinese, and Hong Kong populations [16]. Ho Jung Cho et al. additionally noted the anatomical geometric variations of the femur in Korean individuals compared to Americans and Japanese [17]. He proposed the development of a novel hip prosthesis system tailored for the Asian demographic. De Sousa E et al. assessed the proximal femur characteristics in the Brazilian population using Auto CAD 200 Software and compared the findings with studies from various areas [11]. Rawal BR et al. have suggested parameters for the cementless femoral stem tailored to the Indian population [18]. A disparity of 16.8% was observed in the femoral head offset between the Indian and Swiss populations, potentially influencing soft tissue tension and range of motion. Numerous investigations of proximal femur characteristics have been undertaken in Asian nations, including the Malay population [19], the Chinese population [20], and the Pakistani population [21]. These investigations also support the existence of regional variations in the parameters of the proximal femur; however, the data derived from the Asian population closely resemble the parameters reported in our study. Measurements commonly linked to an elevated fracture risk encompass an elongated hip axis, femur length, an increased neck shaft angle, and a broader femoral neck width [22].  In a retrospective study, El-Kaissai et al. proposed that Caucasian postmenopausal women with hip fractures exhibit a greater length of the femoral neck than those without fractures. The likelihood of hip fracture escalated by 24% with each millimeter rise in femoral neck thickness [23]. Calis et al. reported analogous findings in Turkish women, indicating that the width and angle of the femoral neck were considerably larger in patients with hip fractures [24]. In males, advancing age correlates with increased neck thickness, which exacerbates the development of osteoarthritis by heightening cam impingement [25].

The current study reported a mean femoral length of 42.65 ± 2.57 cm on the right side and 42.48 ± 3.02 cm on the left side (p = 0.764). The femoral head diameter was 42.32 ± 2.94 mm on the right and 42.01 ± 3.58 mm on the left (p = 0.525), but the femoral neck length was 44.64 ± 8.02 mm on the right and 44.27 ± 5.96 mm on the left (p = 0.908). The femoral neck thickness measured 22.81 ± 2.08 mm on the right and 23.92 ± 2.96 mm on the left (p = 0.598). The femoral neck diameter was considerably greater on the right (34.12 ± 3.78 mm) than on the left (31.46 ± 3.21 mm; p = 0.007). The cervicodiaphyseal angle was substantially more obtuse on the left side (130.41 ± 3.12°) compared to the right side (127.24 ± 4.38°; p = 0.002) (Table 1). Prasath RA and Ismail BM noted that the femoral head diameter in the South Indian population was 41.98±1.98 mm [26]. The Synergy hip, featuring a 131° neck-shaft angle and dual offset, demonstrates more reliability in replacement than the Mallory Head component, which has a valgus 135° neck-shaft angle [27]. The elevated offset stem adversely affects the outcomes of hip arthroplasty. Numerous population-based studies have been conducted on the proximal femur. The femurs of Caucasian and American individuals differed from those studied in the Asian population, including individuals from India. Numerous regional studies were conducted in India. The femur characteristics recorded were as follows: femoral head diameter (FHD) was 43.95±3.06, 45.41±3.06, 43.3±4.17, and 45.30±4.7; femoral head offset was 40.23±4.85, 38.18±4.21, and 36.93±5.2; and femoral neck angle (FNA) was 124.42±5.49, 131.87±4.64, 123.5±4.34, and 130.57±3.0 across numerous studies of the Indian population [7,15,16,18,28]. The femoral neck length (FNL) values were 48.4±5.56 and 37.2±4.65 [16,19]. The femoral neck thickness (FNT) and diameter measurements were 31.87±2.91 and 24.90±2.94, respectively [16]. The morphometric variations of the femur in the Indian population exhibit no major regional variances.

Limitations: Limitations of this study were that the age and sex of the femur bones were not studied, as it was not available.

The findings of this morphometric study provide essential anatomical data for designing hip prostheses and fixation plates tailored to the Indian population. Current commercially available implants, primarily based on European anthropometric data, often result in suboptimal fit due to morphological variations in the Indian proximal femur. The parameters obtained in this study, including femoral head diameter, neck dimensions, and cervico-diaphyseal angle, can serve as a reference for developing better-fitting implants that enhance surgical outcomes in total hip arthroplasty (THA) and other reconstructive procedures. Given the anatomical similarities among Asian populations, these data may also be applicable in neighboring regions, facilitating the production of region-specific prostheses that improve biomechanical compatibility, implant longevity, and postoperative functionality.

1.       Chowdhary S, Naushaba H, Begum J, Ahmed S, Khan LF, Parash TH, et al. Morphometrical and topographical anatomy of position of nutrient foramen on fully ossified left femur. Delta Med Coll J. 2013;1(1):13-18.

2.       Nurzenski MK, Briffa NK, Price IR, Khoo CCB, Devine A, Beck JT. Geometric indices of bone strength are associated with physical activity and dietary calcium intake in Healthy older women. J Bone Miner Res. 2007;22(3):416-24.

3.       McGrory J, Morrey BF, Chahalan TD, Kai-Nan AN, Cabanela ME. Effect of femoral offset on range of motion and abductor muscle strength after total hip arthroplasty. J Bone Joint Surg. 1995;77(B):865-69.

4.       Rubin PJ, Leyvraz PF, Aubaniac JM, Argenson JN, Esteve P, Roguin BD. The morphology of the proximal femur: a three dimensional radiographic analysis. Journal of bone and Joint Surgery B. 1992; 74(1): 28-32.

5.       Hushmann O, Rubin PJ, Leyvraz PF, De Roguin B, Argenson JN. Three dimensional morphology of the proximal femur. J Arthroplasty. 1997;12(4):444-50.

6.       Ahmad M, Nanda R, Bajwa AS, Couto JC, Green S, Hui AC. Biomechanical testing of the locking compression plate: when does the distance between bone and implant significantly reduce construct stability? Injury. 2007;38(3):358-64.

7.       Mahaisavariya B, Sitthiseripratip K, Tongdee T, Bohez EL, Vander SJ, Oris P. Morphological study of the proximal femur: A new method of geometrical assessment using 3-dimensional reverse engineering. Med Engg Phys. 2002;24(9):617-22.

8.       Menezes TM, Rocha TDS, De Oliveira BDR, De Albuquerque YML, Caiaffo V. Proximal femoral epiphysis: Manual morphometry versus digital morphometry. Int J Morphol. 2015;33(3):1114-19.

9.       Unnanuntana A, Toogood P, Hart D, Cooperman D, Grant RE. Evaluation of proximal femoral geometry using digital photographs. Journal of Orthopaedic Research. 2010;28:1399-404.

10.    Mourao AL, Vasconcellos H. Geometry of the proximal femur in Brazilian bones. Acta Fisiatrica. 2001;8(3):113-19.

11.    De Sousa E, Fernandes RMP, Mathias MB, Rodrigues MR, Ambram AJ, Babinski MA. Morphometric study of the proximal femur extremity in Brazilians. Int J Morphol. 2010;28(3):835-40.

12.    Granger C, Schutte HD, Bigger SB, Kennedy JM, Latour RA. Failure analysis of composite femoral component for hip arthroplasty. J Rehab Res Develop. 2003;40:131-46.

13.    Reddy VS, Moorthy GV, Reddy SG. Do we need a special design of femoral component of total hip prosthesis in our patients? Indian J Orthop. 1999;33:282-84.

14.    Vaidya SV, Ranawat CS, Aroojis A, Laud NS. Anthropometric measurements to design total knee prostheses for the Indian population. J Arthroplasty. 2000;15:79-85.

15.    Deshmukh TR, Kuthe AM, Ingole DS, Thakre SB. Prediction of femur bone geometry using anthropometric data of Indian population: A Numerical Approach. J Med Sci. 2010;10(1):12-18.

16.    Siwach RC, Dahiya S. Anthropometric study of proximal femur geometry and its clinical application. Indian Journal of Orthopaedics. 2003;37(4):247-51.

17.    Cho HJ, Kwak DS, Kim IB. Morphometric evaluation of Korean femurs by geometric computation: comparisons of the sex and the population. BioMed Research International. 2015;2015(1):730538.

18.    Rawal BR, Rubeiro R, Malhotra R, Bhatnagar N. Anthropometric measurements to design best fit femoral stem for Indian population. Indian J Orthop. 2012;46(1):46-53.

19.    Baharuddin MY, Zulkifly AH, His M, Aziz AA. Three dimensional morphometry of the femur to design the total hip Arthroplasty for Malay Population. Advanced Science Letters. 2013;19(10):2982-87.

20.    Lin KJ, Wei HW, Lin KP, Tsai CL, Lee PY. Proximal femoral morphology and the relevance to design of anatomically precontoured plates: a study of the Chinese population. The Scientific World Journal. 2014;2014(1):106941.

21.    Umer M, Sepah A, Khan A. Morphology of the proximal femur in the Pakistan population. J Orthop Surg. 2010;18:279-81.

22.    Bhattacharya S, Chakraborty P, Mukherjee A. Correlation between neck shaft angle of femur with age and anthropometry: A Radiographic study. Indian Journal of basic and applied Medical Research. 2014;3(3):100-07.

23.    El Kaissai S, Pasco JA, Henry MJ, Panahi S, Nicholson JG, Nicholson GC, et al. Femoral neck geometry and hip fracture risk: the Geelong osteoporosis study. Osteoporosis Int. 2005;16:1299-303.

24.    Calis HT, Eryavuz M, Calis M. Comparison of femoral geometry among cases with and without hip fractures. Yonsei Med J. 2004;45:901-07.

25.    Johnson JK, Renner JB, Dahners LE. Anteroposterior thickening of the femoral neck with aging decreases the offset in men. Am J Sports Med. 2012;40(10):2213-17.

26.    Prasath RA, Ismail BM. A correlative study of morphometric analysis of acetabulum and femoral head in male and female south Indian human cadavers. Journal of Science. 2014;4(1):4-8.

27.    Dolhain P, Tsigaras H, Bourne RB, Rorabach CH, Donald SM, Mc Calden R. The effectiveness of dual offset stems in restoring offset during total hip replacement. Acta Orthopaedica Belgica. 2002;68(5):490-99.

28.    Roy S, Kundu R, Medda S, Gupta A, Nanrah BK. Evaluation of Proximal femoral geometry in plain anteroposterior radiograph in Eastern-Indian population. Journal of Clinical and Diagnostic Research. 2014;8(9):1-3.