Use of computed tomography and magnetic resonance imaging for occult neck of femur fractures: A single-centre study.

Objective: Neck of femur (NOF) fractures are common and serious injuries in the elderly. When a NOF fracture is suspected but is not clearly visible on radiographs, guidelines recommend magnetic resonance imaging (MRI), or computed tomography (CT) if MRI is not available/contraindicated. The aim of our study was to review the use of CT and subsequent MRI for suspected NOF fractures in patients with negative or equivocal radiographs.

Methods: A retrospective review of adult patients with negative or equivocal plain radiographs with suspected NOF fractures presenting between 1 July 2015 and 30 June 2017 was performed. Review of CT and subsequent MRI studies was performed with documentation of reported findings, time intervals from plain radiographs to CT and MRI and final outcomes.

Results: A total of 184 CT studies in 181 patients were reviewed; median age was 82 years (interquartile range 71-89 years) with 110 (60.8%) female patients. CT reported 20 occult fractures; all proceeded to surgery. MRI was performed in 23 patients and revealed additional four NOF fractures missed by CT. An additional fifth fracture missed by CT was confirmed by follow-up radiographs. Median time was approximately 4 h from radiographs to CT and approximately 56 h from radiographs to MRI.

Conclusion: Access to CT for evaluation of suspected occult NOF fractures is much quicker compared to MRI. When CT results are negative with on-going clinical suspicion of an occult fracture, MRI should be performed in a time efficient manner.