Morphological and topographical anatomy of nutrient foramens in human metacarpals and their surgical importance.

Purpose: Trauma to the hand is extremely common, often resulting in metacarpal fractures and dislocations. The surgical intervention may be required for restoration of function and appearance. The preoperative, topographical knowledge of the nutrient foramens is valuable in such operative procedures to preserve the circulation for healing and good postoperative results.

Methods: The topographic and morphometric analysis of 250 non-pathological metacarpals (fifty each from first to fifth) was performed and the foraminal index of each metacarpal was evaluated.

Results: All the metacarpals were having single nutrient foramen except the second metacarpal which showed double nutrient foramens in two cases. The nutrient foramen was situated on the medial surface of first and second metacarpals and on lateral surface in third, fourth and fifth metacarpals in majority of the cases; however, their presence on anterior border (2.8%) was also noticed. The direction of the foramen was always away from the growing end. In 88, 98.1, 90, 94 and 100% of first to fifth consecutive metacarpals, foraminal index ranged between 33.3 and 66.6, indicating their presence on middle third of the shaft.

Conclusions: Though the majority (94%) of foramens were present on the middle third of the shaft, their presence on the proximal (2.8%) and distal third (3.2%) of the shaft cannot be ruled out. The presence of nutrient foramens on the anterior border of third metacarpal has not been classically reported. This information may be important for radiologists to avoid misdiagnosing them as pathology.