ANATOMICAL VARIATIONS OF DIAPHYSEAL NUTRIENT FORAMINA OF HUMERUS IN EGYPTIAN POPULATION
Doaa M. Shuaib and Sarah M. Kaooh
Anatomy Department, Faculty of Medicine, Cairo University
Background: Understanding of the anatomy of nutrient foramina is important in clinical practice. Fractures or surgical procedures passing through the nutrient foreman are the main causes of delayed union or non-union of the bones. Non-union of the humeral shaft remains a difficult clinical problem. Aim of the work: To analyze the number, the size, the location and the direction of the nutrient foramina in the diaphysis of humerus in Egyptian population. Material and methods: The present study consisted of 224 adult humeri (108 right and 116 left). The bones were collected from the Department of Anatomy, Faculty of Medicine, Cairo University. In each bone, the following parameters were observed; the number of nutrient foramina (NF), the location of the foramen in relation to the surfaces and borders of the bone, the size of the foramen and the direction of the nutrient canal. The total length and distance of the nutrient foramen from the proximal end of the bone were measured using measuring tape. Anteroposterior and transverse diameters of the bones at the level of the nutrient foramen were also measured using sliding Vernier caliper. Foraminal index was calculated using Hughes formula. Results: The majority of the humeri (64.7%) had single NF, while in 2.7% of humeri NF was absent. 47.6% of nutrient foramina were of medium size (0.5-0.9 mm). Most of the nutrient foramina (60.6%) were present in the anteromedial surface of the bones. The mean total length of humeri was 30.32 ± 2.88 cm. The mean distance of foramina from proximal end of the bones was 17.03±2.24 cm. At the level of the nutrient foramen, the mean anteroposterior diameter was 16.87± 2.48 mm and the mean transverse diameter was 14.88± 2.98 mm. 94.0% of nutrient foramina were observed in zone II (middle third of the shaft). Conclusion: The results of the present study show that there are variations in the number, location and size of nutrient foramina in humerus among Egyptian population. An accurate knowledge of the location of the NF in humerus can be useful in certain surgical procedures such as bone grafting and microsurgical bone transplantation.