Popis: |
Intramedullary nailing is an accepted and commonmethod of treating long-bone fractures. These nailsareusuallylockedwithscrewstocontrolthelength,alignmentandrotationoftheinstrumentedbone.Asthepatientwalksandappliesloadtotheirleg,forceis transmitted from the intact distal bone, along thescrewstothenail,andthenoutproximallyalongthescrews to the intact cortical bone, bypassing thefracture, as in Fig. 1. This cyclical force may even-tually induce failure of the screws.Interlocking screws are liable to fail in caseswhere union is delayed or absent, as the screws willbeexposedtoahighernumberofcycles.Failurecanoccur between 1 and 120 months following insertionofthescrew. |