Three-year outcomes of intracapsular femoral neck fractures fixed with sliding hip screws in adults aged under sixty-five years

Abstract

Introduction: Intracapsular femoral neck fractures remain associated with high rates of post-traumatic femoral head necrosis, non-union, and revision surgery.

Aim: Our aim was to identify factors associated with revision surgery in intracapsular femoral neck fractures treated with sliding hip screws (SHS) in adults aged <65 years.

Patients and methods: Consecutive admissions were identified retrospectively from the Royal Victoria Hospital, Belfast, which was the largest volume hospital on the National Hip Fracture Database. Of 2201 hip fractures between 1st August 2008 and 31st December 2010, 97 (4%) intracapsular fractures treated with SHS in adults <65 years were followed for a mean of 2.9 years (range 0-6.6).

Results: Twenty-one (22%) hips were revised to arthroplasty. Avascular necrosis developed in 28 (29%) femoral heads. Eight (8%) fractures proceeded to non-union. Displaced fractures (p<0.001, Fisher's exact [FE]), posterior comminution (p=0.049, FE), chronic respiratory disease (p=0.006, FE) and residual distraction (p=0.011, χ²) were associated with revision to arthroplasty. Multiple regression found displaced fractures (p=0.006) and chronic respiratory disease (p=0.017) significant; in the latter 4 of 6 were revised (67%), including all four patients with chronic obstructive pulmonary disease (COPD). Eleven (11%) individuals required walking aids before injury, which rose to 34 (35%) at one year (p<0.0001, χ²). Eighty-nine (92%) individuals could walk alone outdoors before injury, but only 76 (78%) at one year (p=0.009, χ²).

Conclusions: Displaced fractures in individuals with chronic respiratory disease should be considered high risk for revision to arthroplasty. Posterior cortex deficiency should be evaluated prior to choice of operation. Fracture biology and revascularisation play a greater role than operation timing. A significant proportion of individuals do not recovery pre-morbid mobility by one year.

Keywords: Femoral neck fractures; Femur head necrosis; Fracture fixation, internal; Fractures, ununited; Pulmonary disease, chronic obstructive.