Displaced femoral neck fractures in the young: significance of posterior comminution and raised intracapsular pressure

Abstract

Osteosynthesis in fracture neck of femur (NOF) in young is a universally acceptable procedure. Various factors affect the outcome; with AVN (avascular necrosis) and non-union primarily contributing to adverse results in such patients. To identify factors affecting outcome of displaced fracture NOF, a prospective cohort study was carried out in the setting of a tertiary care centre in developing country. 27 consecutive patients with displaced fracture NOF suitable for osteosynthesis underwent closed reduction and fixation with three 6.5 mm cancellous cannulated screws. A record of posterior comminution and its extent (as seen on CT scan) and the intracapsular pressure difference between the fractured and the opposite side was kept in all the patients. The patients were followed-up for 1 year. The main outcomes measured at 1 year were non-union (as identified by CT scan) and AVN (as identified by bone scan). Cases with pressure difference >30 mm were found to have a higher rate of AVN and this result was found to be statistically significant (p value 0.034). The patients with significant posterior comminution were found to have higher non-union rates and this result was also found to be statistically significant (p value 0.04). Prognosis of displaced fracture NOF is significantly associated significant with posterior comminution and intracapsular pressure difference between fractured and normal side.