Page 1 of 4 Research study

Incidence of third and hypotrochanteric fossa Anatomy in human femora in Indian population. S Ghosh1*, M Sethi1, N Vasudeva1

Abstract The knowledge of the occurrence stabilization and control of the thigh Introduction would be crucial for the diagnosis and indicating medio-lateral reinforcement Third trochanter is described as an management of pertrochanteric to resist high mechanical stress in erect 5 oval at the superior end of fractures and also in the study of posture and locomotion. Different the . The importance microevolutionary trends in the varieties of impressions are seen at the of the third trochanter in anthropometric and comparative site of the insertion of studies of humans. ranging from rounded or oblong

pertrochanteric fractures have been recently hypothesized to be correlated tubercle, Third Trochanter, to a ridge or with the fracture break lines in Introduction a prolonged elevation, Gluteal pertrochanteric fractures. The third In many anthropometric studies the tuberosity, or a groove known as trochanter may function to provide third trochanter and the Hypotrochanteric Fossa. Most increased skeletal mass as a hypotrochanteric fossa are commonly commonly seen gluteal tuberosity is reinforcement mechanism for the used non metric variations of the well described in textbooks of anatomy. proximal diaphysis in response to postcranial skeleton. They serve for Hence the study analysed the presence increased ground reaction force. The descriptive purposes of the proximal of third trochanter and hypotrochanteric fossa is considered end of the in various ethnic hypotrochanteric fossa in an Indian population. to be a varied manifestation of the groups. The third trochanter functions attachment of gluteus maximus to provide an attachment area for the present on the posterior superior part ascending tendon of the gluteus Materials and methods of the femoral diaphysis. Due to the maximus. This skeletal variant, when The study was conducted on 152 adult paucity of literature on the incidences present, occurs as an oblong, rounded dried femora collected from the disclosure.

of third trochanter and or conical, roughened or smoothened osteology museum of the department of hypotrochanteric fossa in Indian bony elevation which may be Anatomy, Maulana Azad Medical population, this study was continuous with the gluteal ridge and College, New Delhi, India. The presence undertaken. is manifested as a distinct femoral of third trochanter and

Materials and methods entity.1 The correlation between hypotrochanteric fossa was noted and

preparation, readapprovedand preparation, finalmanuscript.the

The study was conducted on 152 adult muscle insertions and topography of photographed by a SONY DIGITAL t dried femora in the Department of break lines in pertrochanteric CAMERA HX7 against a dark Anatomy, Maulana Azad Medical fractures of the proximal femur has background. For this study, the third College, New Delhi, India. The positive been recently discussed. A study trochanter is defined as the osseous findings were photographed. The suggested that covered only with tubercle in the superior part of the significance of the correlation was periosteum with no reinforcing gluteal tuberosity. It was present lateral found out using Chi-square test. elements of the attachments of to the line connecting the highest point Results muscles and ligaments, represent of the and the

In our study, third trochanter and the minor resistance for onset of superior bifurcation of the . Conflict of interests: None declared. hypotrochanteric fossa were found to fractures. Variability in the sizes and Each trait was analysed for side and occur in 6.6% and 31.6% of the total shapes of pertrochanteric fracture gender. The results were processed

assessed. The hypotrochanteric fragments depend on variability of the using SPSS version 17.0 for significance declared. fossa was seen significantly higher on locations and sizes of soft tissue of the findings using p value and Chi- right side. Both the traits were found attachment areas at specified sites on square test. to be more in males. the proximal femur.2 In this regard the Conclusion osseous, cartilaginous and tendinous Results This study dealt with the incidence of complex of the third trochanter could The tabulated (Table 1) and graphic third trochanter and hypotrochanteric be a preventive factor and representation of the occurrence of the fossa in the Indian population due to determinant of the fracture location three manifestations at the attachment 3,4 scant previous literature. and shape. The strong entheseal of Gluteus maximus i.e. third

development in the femoral trochannter, gluteal tuberosity (Figure

All authors contributedAll andconception to design, manuscrip All authors All abide bythe Association for Medical Ethics (AME) ethical rules of *Corresponding author attachment of the gluteus maximus 4) and hypotrochanteric fossa has been Competinginterests: None Email: [email protected] suggest a strong mechanical effort of shown the joint in extension, lateral 1Maulana Azad Medical College, New Delhi, India Licensee OAPL (UK) 2014. Creative Commons Attribution License (CC-BY)

FOR CITATION PURPOSES: Ghosh S, Sethi M, Vasudeva N. Incidence of third trochanter and hypotrochanteric fossa in human femora in Indian population. OA Case Reports 2014 Feb 25;3(2):14. Page 2 of 4

Research study

Table 1: Incidences of various traits in male and female right and left femora

Number of femur

Trait Males Females Incidence Right Left Right Left

Third Trochanter 3 4 1 2 6.6%

Gluteal Toberosity 18 15 16 12 40.1%

Fossa 16 10 16 6 31.6% Hypotrochanterica

were present in 31.6 % of the total pertrochanteric fracture. They Figure 1: Left male Femur showing femora analysed. (Table 1) It was suggested that absence of reinforcing smooth oblong elevated third found to be significantly high on the elements of muscle and ligamentous trochanter. right side. (Table 2) The gender attachments, represented sites for the differences for the trait were beginning of fractures.2 Previous prominent in males. (Table 3) literatures in Indian populations on the third trochanter are scanty. Our study found it significant enough to report the Discussion incidence in an Indian population. The The third trochanter has been incidence of the third trochanter in our described to be significant in study is 6.6% with left sided anthropometric, comparative and predominance; it also displays a gender disclosure. functional studies. It plays an

variation, being higher in males. Our important role as a useful landmark results are comparable to a study done for biomechanical and densitometry on excavated femora from Poland studies as the access point of choice to which showed an incidence of 6.2%. approach the medullary cavity.

However they did not take any gender preparation,read approvedand thefinal manuscript. Recently workers have hypothesized or side variations into consideration.3 t that muscle insertions and ligament Another study which reported the side attachments have an impact on the variations in Whites and Negroes, course of typical break lines in the documented higher incidence on the area of the trochanteric mass. They right side in the White and on the left conducted a radiologic evaluation of side in the Negro population; it also patients suffering from reported the trait to be more common pertrochanteric fractures and found a in females in both Whites and Negroes.6 potential morphological correlate

The fossa hypotrochanterica is a fossa, Conflict of interests: None declared. Figure 2: Left female Femur showing between muscle insertions and the groove or pit at the site of insertion of roughened oval elevation third course of the break line in a typical trochanter.

declared.

Table 2: Chi square test significance of side variation of the trait in Figure 5 for better correlation. The third trochanter (Figure 1 and Figure 2) was present in 6.6% of the femora. Trait Right Left Significance (Table 1) Although the incidence was higher on the left side it was not Third Trochanter 4 6 0.57 statistically significant. (Table 2) It demonstrated a gender variation being higher in males (p value not Hypotrochanteric Fossa 32 16 0.005*

significant) (Table 3). The

Competinginterests: None authors All contributed conceptionto and design, manuscrip authors All abide bythe Association for Medical Ethics (AME) ethical rules of Hypotrochanteric fossae (Figure 3) * Significant at 1 % level of significance

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The third trochanter may perhaps serve Table 3: Chi square test significance of gender variation of the trait to increase attachment surface area for Trait Male Female Significance the gluteal musculature thereby providing greater efficiency of contraction. Gluteus maximus function Third Trochanter 7 3 0.191 may exert a mechanical loading on the third trochanter thereby altering surface morphology. The presence of Hypotrochanteric Fossa 26 22 0.485 bony crests, ridges and tuberosities are directly correlated to the function of 14 Gluteus Maximus on the femur. The It was also higher in males but not of contiguous muscle activity. presence of gluteal ridge, third significance. Significant right side trochanter or fossa hypotrochanterica predominance was also documented are all associated with Gluteus in Negros but not in Whites. This maximus insertion in man. In Gorillas, study also did not report any Chimpanzees and Orangutans, fossa significant gender variation.6 The hypotrochanterica is found at the phenotypic development and muscle attachment whereas in expression of discontinuous skeletal Gibbons a gluteal ridge is found.7 So traits were originally considered to be the exact aetiology still remains controlled by genetic factors.8 Recent obscure as to why in certain cases a researches indicate the significance of ridge or a fossa is found. This various biological and environmental spectrum of ridge, trochanter and factors such as age, sex, nutritional fossa may possibly represent a status or side dependence influencing microevolutionary trend. Hence our the manifestation of certain non study took into account the incidence metric traits in non human and human of these traits in Indian femora, not populations.9,10,11 Local mechanical mentioned in any previous study. In factors also represent potent sources

our study, the Hypotrochanteric of epigenetic information which disclosure. fossae were present in 31.6 % of influence the incidence and femora with higher significant expression of discontinuous Figure 4: Left male femur showing a incidence on the right side. variants.12,13,14 Expression of the third ridge at the attachment of Gluteus trochanter may be affected by Maximus – Gluteal Tuberosity.

mechanical stress exerted by the

preparation,read approvedand thefinal manuscript.

gluteus maximus; this muscle t functions to decrease limb speed during the late swing and heel strike

phases of locomotion.

Conflict of interests: None declared.

declared.

Figure 3: Right female Femur showing Hypotrochanteric Fossa. Figure 5: A graphic representation of the traits with respect to gender and side of bone.

All authors All contributed conceptionto and design, manuscrip authors All abide bythe Association for Medical Ethics (AME) ethical rules of Competinginterests: None

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Research study

Conclusion 8. Carolineberry A, Berry RJ. The presence of third trochanter at Epigenetic variation in the human the proximal part of the femur has cranium. J Anat. 1967 Apr;101(Pt been found to alter the break lines in 2):361-79. the pertrochanteric fracture patients. 9. Howe, W L. and Parsons, P A. This study dealt with the incidence of Genotype and environment in the third trochanter and hypotrochanteric determination of minor skeletal fossa in the Indian population due to variants and body weight in mice. J scant previous literature. The Embryol Exp Morphol 1967;17:283- knowledge of the occurrence would 92. be crucial for the diagnosis and 10. Dahinten SL, Pucciarelli HM. Effect management of pertrochanteric of age, sex and nutrition on fractures and also in the study of discontinuous traits of rat skull. Acta microevolutionary trends in the Anat (Basel). 1981;110(2):159-63. anthropometric and comparative 11. Pucciarelli, H. M., The influence of studies of humans. experimental deformation on neurocranial Wormian bones in rats. References Am. J. Phys. Anthropol. 1974;41: 29– 37. 1. Lozanoff S, Sciulli PW, Schneider 12. Moss ML. Genetics, epigenetics, KN. Third trochanter incidence and and causation. Am J Orthod. 1981 metric trait covariation in the human Oct;80(4):366-75. femur. J Anat. 1985 Dec;143:149-59 13. Moss ML, Moss-Salentijin L. The 2. Bartoska R, Baca V, Kachlik D, muscle bone interface: An analysis of a Marvan J, Dzupa V. The correlation morphological boundary. 1978. p39- between muscles insertions and

71. Monograph 8, Ann Arbor, Centre topography of break lines in for Human Growth and Devlopment, pertrochanteric fractures: a University of Michigan. comprehensive anatomical approach 14. Lozanoff S, Sciulli PW, Schneider of complex proximal femur injuries. KN. Third trochanter incidence and disclosure. Surg Radiol Anat. 2013 Apr 30.

metric trait covariation in the human 3. Bolanowski W, Smiszkiewicz- femur. J Anat. 1985 Dec;143:149-59. Skwarska A, Polguj M, Jedrzejewski K

S. The occurrence of the third

trochanter and its correlation to

preparation,read approvedand thefinal manuscript.

certain anthropometric parameters of t the human femur. Folia Morphol. 2005. 64, 3, 168-75. 4. Hrdlička, A. The gluteal ridge and gluteal tuberosities (3rd ). Am. J. Phys. Anthropol. 1937; 23: 127– 198. doi: 10.1002/ajpa.1330230202. 5. Belcastro MG, Mariotti V, Facchini F,

Bonfiglioli B. Musculoskeletal stress Conflict of interests: None declared. and adult age markers in the Krapina Hominid collection: the study of

Femora. Period Biol 2006 Apr 27. 108, declared.

3, 319–329. 6. Finnegan M. Non-metric variation of the infracranial skeleton. J Anat. 1978 Jan;125(Pt 1):23-37. 7. Appleton A B. On the Hypotrochanteric Fossa and Accessory Adductor Groove of the Primate Femur. J Anat. 1922 April; 56(Pt 3-4): 295–306.

Competinginterests: None authors All contributed conceptionto and design, manuscrip authors All abide bythe Association for Medical Ethics (AME) ethical rules of

Licensee OAPL (UK) 2014. Creative Commons Attribution License (CC-BY)

FOR CITATION PURPOSES: Ghosh S, Sethi M, Vasudeva N. Incidence of third trochanter and hypotrochanteric fossa in human femora in Indian population. OA Case Reports 2014 Feb 25;3(2):14.