Abstract
Purpose
Intramedullary fixation of clavicle fractures requires an adequate medullary canal to accommodate the fixation device used. This computer tomography anatomical study of the clavicle and its medullary canal describes its general anatomy and provides the incidence of anatomical variations of the medullary canal that complicates intramedullary fixation of midshaft fractures.
Methods
Four hundred and eighteen clavicles in 209 patients were examined using computer tomography imaging. The length and curvatures of the clavicles were measured as well as the height and width of the clavicle and its canal at various pre-determined points. The start and end of the medullary canal from the sternal and acromial ends of the clavicle were determined. The data was grouped according to age, gender and lateralization.
Results
The average length of the clavicle was 151.15mm with the average sternal and acromial curvature being 146° and 133° respectively. The medullary canal starts on average 6.59mm from the sternal end and ends 19.56mm from the acromial end with the average height and width of the canal at the middle third being 5.61mm and 6.63mm respectively.
Conclusion
The medullary canal of the clavicle is large enough to accommodate commonly used intramedullary devices in the majority of cases. The medullary canal extends far enough medially and laterally to ensure that an intramedullary device can be passed far enough medially and laterally past the fracture site to ensure stable fixation in most middle third clavicle fractures. An alternative surgical option should be available in theatre when treating females as the medullary canal is too small to pass an intramedullary device past the fracture site on rare occasions. Fractures located within 40mm of the lateral or medial ends of the clavicle should not be treated by intramedullary fixation as adequate stability is unlikely to be achieved.
MULTIPLE DISCLOSURES
