Morphometry of adult humerus bone in Moradabad region

Background: Morphometric examination of upper and lower limb can be useful to medical anthropologists, archaeologists, forensic experts and medico legal studies. The aim of our study was to determine length of humerus and humerus segment.  Materials and methods: Total of 80 humerus (40 right and 40 left) were collected from the department of Anatomy, Teerthanker Mahaveer Medical College and Research Center and studied. Results were expressed as mean±sd. The parameters measured were maximum length of humerus (MHH), distance between articular segment of humerus head and greater tuberosity (H1), caput humeri and collum anatomicum (H2), proximal and distal point of olecranon fossa (H3), distal point of olecranon fossa and trochlea humeri (H4) and proximal edge of olecranon fossa and proximal point of trochlea humeri (H5).  Results:  Mean MHH, H1, H2, H3, H4 and H5 were found to be 302±2.14mm, 6.4±1.3mm, 39.3±5.4mm, 27.4±2.4mm, 26.1±2.1 and 34.5±6 on the right and 297.5±2.1mm, 6.5±1.3mm, 39.2±4.8mm, 27.5±2.6mm, 22.1±2.3 and 32.6±3.5mm on the left humerus respectively Conclusion: Our study supplies the mean values of the different morphometric measurements from the humerus that may be useful in forensic, anatomic and archeological cases.


Introduction
Almost all bones of the human skeleton show some degree of sexual dimorphism. The cross-sectional area of long bones is greater in males compared to females and this is tough to reflect more rapid periosteal bone growth in boys 1 . But it is unclear whether these findings reflect gender differences in bone size or shape; previous studies tried to confirm the factors that affect the long bone dimensions and to explain the phenomenon of the different lengths between the right and left humerus 2, 3 . Anthropometric techniques have been commonly used to estimate stature and bone length from the skelet al remains and unknown body parts by anthropologists, medical scientists and anatomists for over a hundred years 4,5,6 . In many situations when the full length of long bones may not be available some methods can be used, as per as studies of Wright 7 and Mysorekar 8 .
In the absence of pelvis and cranium, morphometric analysis is frequently carried out on the remains of the long bones of the individual in anthropology and forensic science investigations 9,10,11 . Muller was first to define 5 segments for the humerus using the margins of articular surfaces and key points of muscle attachment 7 . This segment measurement is very helpful for determining the humerus length 12 . It is also very important for anatomic and forensic science and helps the investigator to define the identity of a skeleton. These data give evidences to indicate the characteristic features of a population for archaelogical materials 7,13,14 . The humerus offers important advantages over other long bones in that its entire outline can readily be traced on total body X-ray absorptiometry (DXA) images, and its shape can be modeled as a cylinder with reasonable accuracy 15 .
Therefore the present study was conducted to determine the mean values of humerus segments in Moradabad region, which may be useful to the anatomist and forensic investigators.

Result
The mean values of different segments of humerus (H1, H2, H3, H4 and H5) and maximum length of humerus (MHH) are shown in milimeter (mm) in the table 1. The results were calculated in terms of mean ± sd The mean maximum height of the humerus (MHH: mean distance between caput humerus and trochlea of humerus A-F) was 302±21.4 mm in the right side and 297.5±21.1 mm in the left side The mean distance (H1) from caput humeri (A) to grater tuberosity of humerus (B) was 6.4±1. 3

Discussion
The humerus is the longest and largest bone of the upper limb and it is very important to identify the humeral length from the segmental measurements. In forensic anthropology, a method for estimating height based on the distances of segments of long bones is important. 16 . In our study, the mean values of the maximum humerus length (MHH) of the adult humerus were found to be 302.6±21.4 & 297.5± 21.1 mm on the right and left side respectively. Our results were similar and comparable to Somesh et al 17 , Turkish 16 and Spanish population 12 but there were significant differences with Bulgarian and Maya populations 12 . In a study of the Portuguese population made with fresh bones the mean values of total humerus length were greater than our dry bones. It was reported over 100 years ago that dry bones are sl ightly smaller than fresh ones and this difference has been established as approximately 2 mm 18 .
The mean distance (H2) from caput humeri to collum anatomicum was 39.3±5.4mm on right and 39.2±4.8mm on left side. This was comparable to that of SD Desai et al who found the distance to be 39.6±6.3mm on right and 39.1±6.1mm on left side respectively 19 . On comparisom with Turkish population, it (H2) was 41.0 ± 5.1 mm and 40.9 ± 3.9 mm on the right and left side respectively 16 . Similarly, in a study from Guatemala the distance was 32.8 ± 2.7 mm and it is therefore evident that there are differences in the values obtained as against previous studies 7,18,20,21 .
In anatomical studies it was reported that the highest point on the articular segment of the humeral head is found 6 to 8 mm above from the most proximal point of the greater tuberosity 22,23 . This relationship is important because the relative height of the greater tuberosity determines the amount of subacromial clearance as the arm is elevated. Moreover in clinical assessment this point is important for the treatment of isolated greater tuberosity fractures which extends along the epiphysial lines of the proximal humerus and its segments, causing their displacement to various degrees 16,17 . In our study we found this distance (H1:distance between articular segment of humeral head and the greater tuberosity) on the right humerus to be 6.4 ± 1.3 mm and 6.5 ± 1.3 mm on left humerus. Our mean values are similar to other anatomic studies 16,23 .
Olecranon fractures occur in 10% of all upper extremity lesions. The lesion might be the result of indirect or direct trauma, especially forced hyperextension of the elbow joint 24 . The distance between proximal and distal margin of olecranon fossa (H3) according to our study was 27.4±2.4mm on right and 27.5±2.6mm on left side. In the study of SD Desai et al, H3 was 38.3±1.9mm on right and 39.7±2.5mm on left side 19 whereas inTurkish population it was found to be 24.2 ± 2.07 mm and 23.9 ± 2.63 mm on the right and left humerus respectively 16 17 . In an archeological study the distance between the proximal and distal margin of olecranon fossa was identified as 20.2 ± 1.9 mm for females and for males as 20.3 ± 1.3 mm 25 . In another study the distance (H4) between the distal margin of the olecranon fossa and trochlea was 14.2 ± 1.8 mm on the right humerus for males 7 whereas in our study this was found to be 26.1±2.9mm on right humerus and 22.1±2.3mm on left humerus respectively. Our values were more than that of Turkish (20.0±2.2 mm and 19.7±2.5mm) population 16 but the mean distance H4 obtained in the study of SD Desai et al 19 and Somesh et al 17 were less than that of Turkish population.
IJBAR (2014) 05 (03) www.ssjournals.com The distal humerus has a unique and special anatomy and it freely articulates with the bones of the forearm, the radius and ulna 16 and fractures involving it may pose several reconstructive problems and complications 17 . Therefore these fractures are difficult for orthopedic surgeons to treat. Various implants are available for the diverse fracture patterns observed in the distal humerus and these plates are contoured specifically for the anatomy of this region. Anatomically based precontoured condylar plate systems that can assist with fracture reduction have been developed 26 . When we assessed the distance from the proximal margin of the olecranon fossa to the distal trochlea (H5), it was found to be 34.5±3.6 mm (right) and 32.6±3.5mm (left). These values were similar to the results of Somesh et al 17 but our values were more than that obtained in the study of SD desai et al 19 and much less than that of the Turkish population 16 .

Conclusion
Knowledge of the morphometric values of humerus segments is important in forensic, anatomical and archeological cases in order to identify unknown bodies and stature. It is also helpful for the clinician in the treatment of proximal and distal humerus fra ctures. Therefore our study supplies the data of the different morphometric measurements from the humerus.