18 KMUJ 2014, Vol. 6 No. 1 ORIGINAL ARTICLE 1  Department of Anatomy, KMU Institute of Medical Sciences (KIMS), Kohat, Pakistan Email: dr.sahibkhan@yahoo.com 2 Department of Anatomy, Khyber Medical College, Peshawar, Pakistan Date Submitted: September 23, 2013 Date Revised: February 12, 2014 Date Accepted: February 15, 2014 ANATOMICAL VARIATIONS IN DIAPHYSEAL NUTRIENT FORAMINA OF HUMERUS IN CADAVERS FROM KHYBER PAKHTUNKHWA, PAKISTAN Abdul Sahib Khan 1  , Zahid Shah 2 , Qaiser Inayat 2 ABSTRACT OBJECTIVE: This study was aimed at analyzing diaphyseal nutrient foramina with reference to the variation in number, location, position and direction of nutrient foramina of the dry humerus. METHODOLOGY: This analytical study was conducted on 75 adult humerus bones of cadavers from Khyber Pukhtunkhwa, collected from anatomy museum of Khyber medical college Peshawar and Khyber medical university institute of medical sciences (KMU-IMS) Kohat. The damaged bones and bones having pathological anomalies were exclud- ed from the study. In each bone, the diaphyseal nutrient foramen was identified for location, position, number and direction. Measurement was taken through the osteometeric board. The data was statistically analyzed by using SPSS version 17. RESULTS: Out of 75 humerus bones, 68 (90.67%) were having single nutrient foramen and in 74 (98.67%) humerus bones, nutrient foramina were directed distally. Mean distance of the nutrient foramina from the medial epicondyle of the humerus was 9.92±1.93cm in all bones; 10.44±1.92cm on the left sided (n=41) bones and 9.36±1.95cm on the right sided (n=34) bones. Overall, 96% (n=72/75) of nutrient foramina were located on the middle 1/3 rd of anteromedial surface, 2.67% (n=2/75) on the posterior surface and 1.33% (n=1/75) on the antero-lateral surface. While 97.5% (n=33/34) of nutrient foramina on right humeri and 95.13% (n=39/41) of nutrient foramina on left humeri were located on antero-medial side. CONCLUSION: Majority of nutrient foramina of humerus in our set up are single, directed distally and located on the middle 1/3rd of antero- medial surface, reflecting no marked anatomical variation in number, direction and location. KEY WORDS: Diaphyseal Nutrient Foramina, Humerus, Anatomical Variation. THIS ARTICLE MAY BE CITED AS: Khan AS, Shah Z, Inayat Q. An- atomical variations in diaphyseal nutrient foramina of humerus in ca- davers from Khyber Pakhtunkhwa, Pakistan. Khyber Med Univ J 2014: 6(1): 18-21. INTRODUCTION N utrient artery is the main source of blood to a long bone. Nutrient artery of the humerus arises from the brachial artery or profunda brachi. Inner half of the cortex and medulla are vascularized by nutrient artery and the outer half of the cortex is nourished by periosteal vessel and these vessels do not provide an effective collateral supply to the medulla. 1 The nutrient foramina of human long bones are traditionally described as being directed towards the elbow and away from the knee. The possible explanation of this description is that one end of the long bone of the limb is growing faster than the other. 2 Nutrient arteries play an important role during active growth period as well as uniting callus formation in fractured bone. Nutrient artery after entering the shaft through the nutrient foramina obliquely, divides into ascending and descending branches in the medul- lary cavity. Each branch divides into a number of small parallel channels that are terminated in the adult metaphysis by anastomosing with the epiphyseal metaphyseal and periosteal arteries. 3 The main nutrient foramina of hu-merus are found in the middle 1/3 rd of the anteromedial surface, although various variations have been reported in the number and position of the fo- ra-mina. 4 Any manipulation in this area in the form of close or open reduction may cause damage to nutrient arteries, lea-ding to non-union or delayed union The knowledge regarding the nutrient foramina helps the surgeon to avoid these complications during manipulation in the fracture of shaft of humerus. 5,6 There are very few local studies from India 7-9 and one study from Pakistan 10