JKIMSU, Vol. 6, No. 2, April-June 2017 ISSN 2231-4261 ORIGINAL ARTICLE Incidence of Third Trochanter/Crista Glutei in Human Femora in Central Indian Population 1* 2 3 Rupa Chhaparwal , Vishal Bhadkaria , Nidhi Chhaparwal 1Department of Anatomy, Sri Aurobindo Medical College and Post Graduate Institute, Indore-453555 (Madhya Pradesh) India, 2Department of Anatomy, Bundelkhand Medical College Sagar- 470001 (Madhya Pradesh) India, 3 Department of Anatomy, D. Y. Patil Medical College, Pimpri-Pune- 411018 (Maharashtra)India Abstract: Introduction: Background: The third trochanter is a rounded bony The femur is known for being the largest and projection which may be present along the superior longest bone in the human skeleton. This bone border of the gluteal tuberosity of the femur.Sometime supports all of the weight of the body during there is linear elevation along the gluteal tuberosity standing, walking and running. Femur is the most called as crista glutei. If conical projection is present in measured and reported bone of the human skeleton. the gluteal tuberosity, it is called as third trochanter. Researchers have great work on human femora Aim and Objectives: To undertake the study of because it separates humans greatly from primates incidences of third trochanter and crista glutei in and early hominids. It also play great role in central Indian population this study was undertaken biological and forensic science. The structural and to compare it with occurrence in other series. function of the femur requires that it endure these Material and Methods: Fifty dry adult human femora collected from the Department of Anatomy and mechanical loads, by changing its shape, size and examined carefully. The third trochanter was mass. The architecture of each of the femur parts considered to be present only if distinct oval elevation change to meet the functional demands placed on it was separate from gluteal ridge. When there is linear during daily activity patterns [1]. The gluteal elevation along the gluteal tuberosity we considered it tuberosity may be an elongated depression or a as crista glutei. This classification was distinguished ridge. It may at times be prominent enough to merit from that of a gluteal tuberosity. The length and width the unofficial title of “Third Trochanter” [2]. This was measured using a digital vernier caliper. Results: third trochanter is also referred to as the trochanter The total incidence of third trochanter (oval elevation) tertius [1]. In some cases distinct third trochanter is and crista glutei (linear elevation) were found to occur present. This bony knob if present will be located in 14% and 24% with left sided predominance. lateral to the lesser trochanter [1]. The third Conclusion: Important findings of present work trochanter is a rounded bony projection which may highlight the morphometric indices of third trochanter be present along the superior border of the gluteal and crista glutei. Parameters that have been studied in tuberosity of the femur [3]. This skeletal variant, the present work can be utilized for anthropometric, when present, occurs as an oblong, rounded or comparative and functional studies. conical bony elevation which may be continuous Keywords: Third Trochanter, Crista Glutei, Gluteal with the gluteal ridge and is manifested as a distinct Tuberosity, Trochanter Tertius femoral entity [4]. Due to the paucity of literature Ó Journal of Krishna Institute of Medical Sciences University 57 JKIMSU, Vol. 6, No. 2, April-June 2017 Rupa Chhaparwal et al. on the incidences of third trochanter in central Material and Methods: Indian population this study was undertaken and to The experimental sample consisted of 50 dry adult compare it with occurrence in other series. human femora (25 right sided and 25 left sided) of However, factors governing the etiology and unknown age and sex collected from the expression of the third trochanter are not well Department of Anatomy, Sri Aurobindo Medical delineated. The structure is defined as an osseous College and Post Graduate Institute, Indore, prominence, tubercle or, alternatively, as a Madhya Pradesh, India. All the femurs were variation of the gluteal tuberosity with its superior examined carefully to see the presence of third part better developed [5]. Sometime there is linear trochanter. The length and width of the third elevation along the gluteal tuberosity called as trochanter wherever found were measured using a crista glutei. If conical projection is present in the digital vernier caliper (Fig.1). The shape of the gluteal tuberosity, it is called as third trochanter [6]. third trochanter was noted and positive findings The importance of the third trochanter in were photographed. We also measured the length pertrochanteric fractures have been recently of gluteal tuberosity of femur with scale. The third hypothesized to be correlated with the fracture trochanter was considered to be present only if break lines in pertrochanteric fractures. The third distinct oval elevation was separate from gluteal trochanter may function to provide increased ridge. When there is linear elevation along the skeletal mass as a reinforcement mechanism for the gluteal tuberosity we considered it as crista glutei proximal diaphysis in response to increased ground (Fig. 2). This classification was distinguished from reaction force [7]. The third trochanter functions to that of a gluteal tuberosity. provide an attachment area for the ascending tendon of the gluteus maximus. Femoral Results: attachment of the gluteus maximus suggest a strong The total incidence of third trochanter (oval mechanical effort of the joint in extension, lateral elevation) is 14%. Although the incidence was stabilization and control of the thigh indicating higher on the left side which was about 16% and on medio-lateral reinforcement to resist high right side it was about 12% (Table 1). The average mechanical stress in erect posture and locomotion length of third trochanter is about 7.69 mm and [7]. The third trochanter may perhaps serve to width is 4.90 mm on right side. The average length increase attachment surface area for the gluteal of third trochanter is about 15.48 mm and width is musculature thereby providing greater efficiency 7.52 mm on left side (Table 2). The total incidence of contraction. Gluteus maximus function may of crista glutei (linear elevation) was 24% with left exert a mechanical loading on the third trochanter sided predominance. The incidence of crista glutei thereby altering surface morphology. The presence was 16% on right side and 32% on left side. The of bony crests, ridges and tuberosities are directly average length of crista glutei was about 22.15 mm correlated to the function of contiguous muscle on right side and 20.15 mm on left side. The activity [8]. In some species of laboratory average width of crista glutei was about 5 mm on mammals the third trochanter plays an important right side and 5.5 mm on left side. The average role as a useful landmark for biomechanical studies length of gluteal tuberosity was about 5.46 cm on and densitometry and as the access point of choice right side and 4.8 cm on left side (Table 2). for the medullar cavity [8]. Ó Journal of Krishna Institute of Medical Sciences University 58 JKIMSU, Vol. 6, No. 2, April-June 2017 Rupa Chhaparwal et al. Table 1: Incidence of Third Trochanter/ Crista Gluei / Gluteal Tuberosity Observations Percentage Gluteal Tuberosity R – 100 L – 100 Third Trochanter (Oval elevation) R –12 L – 16 Crista Glutei (linear elevation) R –16 L – 32 R - Right, L - Left Table 2: Measurements of Third trochanter/ Crista gluei/ Gluteal tuberosity Observations Length of Gluteal Length / Width of Third Length / Width of Crista Tuberosity Trochanter-Oval Elevation Glutei-linear Elevation (cm) (mm) (mm) Maximum R – 9 R – 13.15/7.60 R – 38.80/ 6.85 L – 8.5 L – 17.28/8.17 L – 30.90/8.60 Minimum R – 3 R – 4.76/3.46 R – 9.54/2.27 L – 2 L – 10.56/6.72 L – 9.48/4.30 Average R – 5.46 R – 7.69/4.90 R – 22.15/5 L – 4.8 L – 15.48/7.52 L – 20.15/5.5 R - Right, L - Left Fig. 1: Showing Measurement of Third Trochanter with Digital Vernier Caliper Ó Journal of Krishna Institute of Medical Sciences University 59 JKIMSU, Vol. 6, No. 2, April-June 2017 Rupa Chhaparwal et al. Fig. 2: Showing Third Trochanter/Crista Gluei/Gluteal Tuberosity (GT-Greater Trochanter, LT- Lesser Trochanter) Discussion: Different varieties of impressions are seen at the maximus muscle. In this case the prominent site of the insertion of gluteus maximus ranging structure at the superior end of the gluteal from rounded or oblong tubercle, third trochanter, tuberosity serves as the trochlea, alternating the to a ridge or a prolonged elevation, or gluteal direction of the tendon before it inserts to the other tuberosity [7]. parts of the tuberosity [9]. The third trochanter is defined as the osseous The definition of the third trochanter used in this tubercle in the superior part of the gluteal study was the osseous tubercle in the superior part tuberosity of the femur. It is localized in the of the gluteal tuberosity of the femur and when majority of cases lateral to the line connecting the there is linear elevation along the gluteal tip of greater trochanter with the superior tuberosity we considered it as crista glutei. This bifurcation of the linea aspera. The third could explain the difference between the results of trochanter has been commonly used as a non- our study and those performed on other metric variant of the post cranial skeleton in populations of the same area. No other workers anthropometric studies of various populations [9]. have mentioned such type of classification of The majority of authors describe the role of the elevation.