Abstract:

BACKGROUND: Intramedullary nails for fixation of clavicle fractures have become a focus. However, the effect of Kirschner wire intramedullary pinning is not satisfactory.
OBJECTIVE: To measure and analyze adult clavicle anatomy related data to develop a new type of adult clavicle fracture fixation in the middle of intramedullary nails, and to explore the advantages and disadvantages. 
METHODS: According to measurement data of 40 adult clavicle and 5 fresh cadaver specimens, a new type of clavicular intramedullary nail was designed, which uses double-threaded Kirschner wire intramedullary pinning, containing hollow thread self-tapping self-drilling screws (Hexagon) fixed pairs of threaded Kirschner wire at both ends in order to achieve a fixed mid-clavicular fractures requirements.
RESULTS AND CONCLUSION: Clavicle length was (14.85±1.22) cm, middle clavicle length (5.89±0.61) cm, the outer segment and the middle angle, as well as the angle between the middle and the medial segment were 125°; the narrowest diameter of middle segment of the clavicle was (1.02±0.15) cm, the inner diameter of the narrowest at the middle clavicular marrow cavity was (0.53±0.16) cm. The intramedullary pinning retrograded from the mid-clavicle fracture and anterograded cortical bone after fracture reduction; after the fracture was fixed, the redundant Kirschner wire was cut, and hollow thread self-tapping self-drilling screws were threaded at both ends with stable and reliable fixation. This new self-made intramedullary nail forms a stable module using a thread containing hollow self-tapping self-drilling screws and fracture at both ends, bridged by intramedullary Kirschner wire, with a supporting and pressing interaction. It is in accordance with the principles of minimally invasion, with satisfactory reduction and reliable fixation. However, related biomechanical data require further investigation.