Aim:Fractures of metacarpals are commonly encountered in hand surgery. For adequate fixation, a thorough knowledge about the anatomy is essential. While fixing the metacarpals with plates and screws, plates are bent to contour the dorsal surface. However, there are no reference values in literature for the location and degree of angulation. The authors studied the dorsal surface of metacarpals in cadavers to gather data regarding the location and degree of angulation of the dorsal cortex. Methods: Cadaveric dissections of 118 metacarpals from 30 hands were performed. A true lateral view of each metacarpal was taken using fluoroscopy. These pictures were analyzed using Image J software. The dorsal cortex angle was measured in each image, and the center of rotation of angulation (CORA) was identified. The distance from the CORA to the base of metacarpal was measured and calculated as a percentage of the metacarpal length. Results: The average dorsal angle of the metacarpals was 11.5°. The average angles for each metacarpal were as follows: 2nd metacarpal = 13° (range, 6-26°; SD, 4.73), 3rd = 10° (range, 1-25°; SD, 5.28), 4th = 11° (range, 1-20°; SD, 4.45), 5th = 12° (range, 2-24°; SD, 5.11). The average location of the CORA from the base of the metacarpal as a percentage of the metacarpal length was identified as follows: 53.5% for the index finger, 52.1% for the long finger, 48.3% for the ring finger and 50.3% for the small finger. Conclusion: These measurements are able to serve as reference values for plate bending while operating on a metacarpal fracture or metacarpal corrective osteotomy. ABSTRACT

Background: Patients with hand masses present for consultation either for pain, loss of function, or cosmetic embarrassment caused by the mass. The majority of hand masses are benign soft tissue tumors. The aim was to review the histology results of hand masses operated on at the Chris Hani Baragwanath Academic Hospital Hand Unit in Johannesburg, South Africa, to explore the relationship of the types of masses according to age, sex, side, and compare the findings with what is in the current literature. Methods: Patients operated on in the hand unit, for hand masses between April 2016 and April 2019 with histology results were included in the study for statistical  analysis. Results: There were 64 males and 105 females with a mean age of 41.03 ± 18.81 years. The most frequent masses were ganglion cysts.  Females appeared to be more affected than males by the different hand masses, but there were no statistically significant differences. Of the 21 giant cell tumors, 15 occurred on the right hand (p-value = 0.021). Conclusion: The profile of hand masses at a high-volume hand unit in Johannesburg, were comparable to the reported literature. There  were no significant differences between sex and diagnosis, however, there was a relationship between diagnosis and side for giant cell tumors of tendon sheaths, requiring further exploration.