Anatomical characteristics of the tibial medullary canal and their implications for intramedullary fixation.

ABSTRACT

The use of intramedullary fixation methods in the tibia is limited by the anatomical characteristics of this bone. In this study, the shape and degree of axial lateral rotation of the medullary canal were determined in 45 human dry cadaver bones using X-ray and computed tomography examinations and direct measurement of rotation in inserted nails. Forty bones (88.8%) had slight and five bones (11.1%) had excessive anterior bowing along the tibial shaft. Six of the 45 bones (13.3%) had an extremely narrow medullary canal. Axial lateral rotation was demonstrated in the middle third of the medullary canal, being on average (+/- SD) 32.35 +/- 16.25 degrees (range 10-75 degrees). This study revealed that extreme narrowing of the medullary canal, axial lateral rotation of the medullary canal, and extreme anterior bowing of the tibial shaft are the anatomical characteristics most likely to cause difficulties when using intermedullary fixation in the tibia.