The significance of good reduction and fixation in displaced subcapital fractures of the femur

Abstract

Summary A series of 97 displaced subcapital fractures treated by triangular fixation confirms previous observations that bony union will normally occur in every case in which good reduction is maintained by sound fixation. Reduction and fixation may be regarded as complementary and equally important factors leading to union. The limits of acceptable reduction defined by Garden have been confirmed, both as to union and as to late segmental collapse. Union is unlikely to occur in a fracture which is under-reduced with varus displacement in the anteroposterior plane, or over-reduced with anterior displacement in the lateral plane. The difference in prognosis hitherto noted between Stage III and Stage IV fractures was not present in this series, union occurring equally readily in each. This may indicate that rigid fixation is of particular importance in the unstable, fully-displaced Stage IV fracture, and that mechanical factors are no less significant than biological ones in securing bony union. The causes of late segmental collapse are not yet fully understood and are probably multiple. In this series there was some radiological evidence of collapse in 21 of the 64 united fractures, but only 4 of these required replacement arthroplasty, the complication otherwise proving to be a manageable one with a clinical result which satisfied the demands of the elderly patient affected.