Incidence, Magnitude, and Predictors of Shortening in Young Femoral Neck Fractures.

OBJECTIVES

To describe the incidence and magnitude of femoral neck fracture shortening in patients age younger than 60 years. Secondarily, to examine predictors of fracture shortening.

DESIGN

Retrospective chart review.

SETTING

Level I trauma centre.

PATIENTS/

PARTICIPANTS

Sixty-five patients with a median age of 51 years (interquartile range: 42-56 years) were included. Seventy-one percent were male, 75% were displaced fractures, and 78% were treated with cancellous screws.

INTERVENTION: Internal fixation with multiple cancellous screws or sliding hip screw (SHS) + derotation screw.

MAIN OUTCOME MEASUREMENTS: Radiographic femoral neck shortening at a minimum of 6 weeks after fixation.

RESULTS

Fifty-four percent of patients had ≥5 mm of femoral neck shortening (22% had between ≥5 and <10 mm and 32% ≥10 mm). Initially, displaced fractures shortened more than undisplaced fractures (mean: 8.1 vs. 2.2 mm, P < 0.001), and fractures treated with SHS + derotation screw shortened more than fractures with cancellous screws alone (10.7 vs. 5.5 mm, P = 0.03). Even when adjusting for initial fracture displacement, fractures treated with SHS + derotation screw shortened an average of 2.2 mm more than fractures treated with screws alone (P = 0.03).

CONCLUSIONS

The incidence of clinically significant shortening in our young femoral neck fracture population was higher than anticipated, and 32% of patients experienced severe shortening of >1 cm. Our findings highlight the need for further research to determine the impact of severe shortening on functional outcome and to determine if implant selection affects fracture shortening.

LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.