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Case Report
Anatomy
Supratrochlear foramen: an incidental finding in the foothills of Himalayas
Abstract
Introduction The lower end of the humerus has two large fossae, the olecrenon fossa and the coronoid fossa, separated by a thin bony plate that rarely bears an opening known as supratrochlear foramen. Supratrochlear fracture of humerus is very common in the paediatric age group, and it can alter the line of fracture as well as management. Due to its clinical relevance, its presence cannot be ignored. This report discusses a case of a supratrochlear foramen. Case report During routine osteology demonstration, we encountered the humerus with supratrochlear foramen. Morphometric analysis was done and compared with the previous literatures. Conclusion This foramen can alter the radiological findings during examination and may get misdiagnosed as osteolytic lesion or cystic lesion. Supratrochlear foramen can alter the line of fracture as it is linked with a small medullary canal, which can modify our decision of point of entry of the nail in the medullary nailing procedure. Therefore, its clinical importance cannot be ignored.
Introduction
A thin plate of bone usually separates olecranon fossa and coronoid fossa of the humerus. At times, this bony plate remains perforated known as supratrochlear foramen (STF), septal aperture or intercondylar foramen of the humerus. The thin plate of bone is always present in between olecranon and coronoid fossae till the age of 7, later it may persist or get absorbed1. Initial reporting of STF was done by Meckel in 1825. STF may cause hyperextension at the elbow joint2. Occurrence of STF is well documented in other animals3,4. STF is of great importance to anthropologists claiming it as one of the points in a satisfying relationship between humans and lower animals2. Seventy-five percent of all injuries of the paediatric age group are fractures of the supracondylar region of the humerus5. Intramedullary nailing of the humerus is sometimes required in the treatment of supracondylar fracture, and it is relatively more difficult in the presence of STF2. This
foramen is always associated with the narrow medullary canal and hence route of pin entry in intramedullary nailing is still a point of debate.Therefore, it is important to have knowledge of STF in the pre-operative planning, treatment of supracondylar fractures and to decide route of pin entry in medullary nailing6. This report discusses a case of a STF.
Case report
During regular osteology demonstration for undergraduate medical students, we encountered a right-side humerus with oval-shaped STF (Figures 1 2). Morphometric analysis revealed its horizontal diameter as 6.22 mm and vertical diameter as 4.64 mm. Edges of STF were 24 mm distal to the medial epicondyle, 29 mm to the lateral epicondyle and 16 mm to the lower border of the humerus. Careful examination of the bone was done, and no other abnormality was noticed. Photographic record of anatomical landmarks was made.
*Corresponding author Email:
[email protected]
Department of Anatomy, Veer Chandra Singh Garhwali Government Medical Science and Research Institute, Srinagar, Uttarakhand, India 2 Department of Anatomy, Government Medical College, Kota, Rajasthan, India 1
Figure 1: Anterior view showing the oval-shaped STF at the lower end of humerus.
Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)
For citation purposes: Soni S, Verma M, Ghulyani T, Saxena A. Supratrochlear foramen: an incidental finding in the foothills of Himalayas. OA Case Reports 2013 Aug 08;2(8):75.
Competing interests: none declared. Conflict of interests: none declared. All authors contributed to the conception, design, and preparation of the manuscript, as well as read and approved the final manuscript. All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
S Soni1, M Verma1, T Ghulyani2, A Saxena1*
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Case Report Conclusion
In radiological examination, STF is radiolucent and may be misinterpreted as cystic or osteolytic lesion; therefore it is essential for the orthopaedicians or radiologists to have prior knowledge of STF.
Figure 2: Posterior view showing the oval-shaped STF at the lower end of the humerus. Table 1 Comparison of STF dimensions Reference
Year
Mean transverse diameter (mm)
Mean vertical diameter (mm)
Nayak et al.8
2009
6.55 (left) , 5.99 (right)
4.85 (left), 3.81 (right)
Krishnamurthy et al.2
2011
6.5 (left), 5.2 (right)
4.7 (left), 4.0 (right)
Veerappan et al.
2013
7.94 (both left and right sides)
6.01 (both left and right sides)
2013
6.22 (both left and right sides)
4.64 (both left and right sides)
Present case
Discussion
9
STF may produce stress and alter fracture of line patterns associated with supracondylar fracture. It may also increase tendency of supracondylar fracture even in case of relatively low-energy trauma7. The mean transverse and vertical diameters of STF reported in the present case are in concordance with the findings of Krishnamurthy et al.2 and Nayak et al.8. Our results were not consistent with the findings of Veerappan et al.9 (Table 1). Shapes of STF were classified as round, oval and triangular and with sieve-like aperture according to Veerappan et al.9, with the oval shape
being most common. It shows that the shape of the foramen in the present case is in accordance with the results of Veerappan et al.9 and Nayak et al.8. Distance of STF from medial epicondyle in the present study is 24 mm and from lateral epicondyle is 29 mm. The mean distance from medial epicondyle was calculated as 26.1 and 28 mm on left- and right-side humerus, respectively, while it was reported as 23.84 mm by Veerappan et al.9 This is almost similar to our case, but the distance from lateral epicondyle is 5 mm more than the case reported by Veerapan et al. as 24.06 mm.
1. Mahajan A. Supratrochlear foramen: study of humerus in North Indians. Prof Med J. 2011 Mar;18(1):128–32. 2. Krishnamurthy A, Yelicharla AR, Takkalapalli A, Munishamappa V, Bovinndala EB, Chandramohan M. Supratrochlear foramen of humerus – a morphometric study. Int J Biol Med Res. 2011;2(3):829–31 3. Haziroglu RM, Ozer M. A supratrochlear foramen in the humerus of cattle. Anat Histol Embryol. 1990;19:106–8. 4. Riesenfild A, Somon M. Septal apertures in humerus of normal and experimental rats. Am J Phys Anthropol. 1975 Jan;42(1):57–61. 5. Houshian S, Mehdi B, Larsen MS. The epidemiology of elbow fracture in children: analysis of 355 fractures with special reference to supracondylar humerus fractures. J Orthop Sci. 2001;6:312–15. 6. Paraskevas GK, Papaziogas B, Tzaveas A, Giaglis G, Kitsoulis P, Natsis K. The supratrochlear foramen of the humerus and its relation to the medullary canal: a potential surgical application. Med Sci Monit. 2010;16(4):119–23. 7. Sahajpal DT, Pichora D. Septal aperture: an anatomic variant predisposing to bilateral low-energy fractures of the distal humerus. Can J Surg. 2006 Oct; 49(5): 363–4. 8. Nayak SR, Das S, Krishnamurthy A, Prabhu LV, Potu BK. Supratrochlear foramen of the humerus: an anatomicoradiological study with clinical implications. Ups J Med Sci. 2009;114:90–4. 9. Veerappan V, Ananthi S, Kannan NG, Prabhu, Karthikeyan. Anatomical and radiological study of supratrochlear foramen of humerus. World J Pharm Pharm Sci. 2013;2(1):313–20.
Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)
For citation purposes: Soni S, Verma M, Ghulyani T, Saxena A. Supratrochlear foramen: an incidental finding in the foothills of Himalayas. OA Case Reports 2013 Aug 08;2(8):75.
Competing interests: none declared. Conflict of interests: none declared. All authors contributed to the conception, design, and preparation of the manuscript, as well as read and approved the final manuscript. All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
References
