Outcomes of Magnetic Resonance Imaging Detected Occult Neck of Femur Fractures: Do They Represent a Less Severe Injury with Improved Outcomes?

Purpose: Occult hip fractures in the elderly can be missed on standard radiographs and are a known cause of morbidity. These are generally diagnosed on either magnetic resonance imaging (MRI) or computed tomography scan, depending upon local hospital policy. While there is an abundance of literature on hip fractures in general, little is known about the clinical outcome of patients with occult hip fractures. The aim of this study was to review the demographics, injury characteristics, management and clinical outcome of patients diagnosed with occult femoral neck fractures on MRI.

Materials and Methods: Using an existing hospital database, a retrospective analysis of all patients with occult hip fractures diagnosed by MRI scan from 2005 to 2014 was conducted.

Results: Sixty-four patients (23 males and 41 females) were included. The mean duration of hospitalisation was 16 days. A significantly higher percentage of patients were discharged to their pre-existing residence compared to National Institute for Health and Care Excellence (NICE) commissioning guidelines (66% vs. 45%). The 30- and 60-day mortalities were 3% and 10%, respectively. Mortality was lower in patients who underwent internal fixation (n=3/31) compared with those undergoing replacement (hemi/total hip arthroplasty) (n=5/12) ( P =0.056).

Conclusion: Patients with occult hip fractures diagnosed on an MRI scan are more likely to be discharged to their pre-existing residence and have lower mortality rates compared to NICE guidelines and National Hip Fracture Database (NHFD).