The lateral radiograph is useful in predicting shortening in 31A2 pertrochanteric hip fractures.

There was a recent call for “a change in the status quo in the management of pertrochanteric hip fractures”1 owing to poor functional outcomes2 and high reoperation rates with current management.3 Specifically, there was a call for research into the prevention of malunion secondary to shortening and shaft medialization. The Orthopaedic Trauma Association (AO/OTA) 31A2 pertrochanteric fracture group4 is at risk for such malunion. The lateral wall in this group is at higher risk for fracture when treated with a sliding hip screw (SHS; 29.8% in the 31A2 group v. 7% in the 31A1 group), which leads to excessive shortening.5 This group is also characterized by variable amounts of comminution along the intertrochanteric line,4,6 which can lead to shortening despite an intact lateral wall.3,7–10 Up to 2.5 cm of shortening has been described in these fractures,3,10 while as little as 1.3 cm11 and 1.7 cm9 has been associated with reduced patient mobility11 and poor functional results.9 The AO/OTA classification accounts for comminution; however, inter-observer agreement within the 31A2 group is “poor”12–14 by the Landis and Koch criteria,15 and “moderate” with the use of a simplified classification.6 Markers predictive of shortening, in addition to lateral wall integrity and quantity of comminution, would therefore be useful. The senior author’s (T.T.) observations have led to the hypothesis that angulation or translation on a routine lateral radiograph is predictive of difficulty with fracture reduction. This fracture characteristic may also be predictive of malunion in 31A2 fractures, specifically of shortening. Current classification systems do not consider the lateral radiograph and may be omitting important and readily available information.4,6 The purpose of this paper is to establish whether the presence of angulation or translation on a cross-table lateral injury film predicts greater shortening in 31A2 hip fractures treated with a sliding hip screw.