Morphological and topographical anatomy of nutrient foramina in human upper limb long bones and their surgical importance

Objectives: To study the morphology and topography of nutrient foramina and to determine the foraminal index of the upper limb long bones. Materials and Methods: The study comprised 243 upper limb long bones, which included humeri, radii, and ulnae. The nutrient foramina were identified macroscopically in all the bones and an elastic rubber band was applied around these foramina. The bones were photographed with the digital camera and foramen index was calculated. Each bone was divided into five equal parts and was analyzed topographically. Results: From our observations, 93.8% of the humeri had single nutrient foramen. The double foramen was observed in 3.1% of the cases and the foramen was found absent in 3.1% of the humeri. In case of radius, 94.4% had single foramen, 1.4% had double foramen, and in 4.2% of the cases, it was absent. With respect to ulna, all the 75 bones had single foramen. The mean foraminal index was 57.6 for the humerus, 34.4 for both the ulna and radius. The majority (70%) of the foramina in humerus were located at the 3/5 _th part, 83.6% of the ulnae foramina at the 2/5 ^th part and 87.7% of the radii foramina at the 2/5th part. Conclusions: The study has provided additional information on the morphology and topography of nutrient foramina in upper limb long bones. The knowledge about these foramina is useful in certain surgical procedures to preserve the circulation. As microvascular bone transfer is becoming more popular, a convention for the anatomical description of these foramina is important.