Floating knee

Summary

We report on two prognostic studies (class of evidence II and III) that examined factors for poor outcomes following simultaneous ipsilateral tibial and femoral fractures, ie “floating knees”. Overall, most factors examined were not statistically significant predictors of poor outcomes. Evidence for age and various fracture characteristics as prognostic factors, overall, was inconsistent. Specific factors may, however, be predictors for specific outcomes:

Open fractures were associated with knee stiffness and delayed weight bearing and segmental fractures increased the time to union.

Increasing age appears to be a significant predictor of time to union and time to full weight bearing yet not a predictor for unsatisfactory functional outcome.

Increased pack-years of smoking predicted increased knee stiffness, delayed time to union and delayed time to full weight bearing.

Higher injury severity score (ISS) was only significant for delayed time to full weight bearing.