Preliminary image findings of lower limb stress fractures to aid ultrasonographic diagnoses: A systematic review and narrative synthesis

Abstract

Introduction This systematic review investigates which image appearances are most common when diagnosing lower limb stress fractures using ultrasound imaging, with the aim of outlining an image critique guideline for operators to support confident diagnoses. Method A comprehensive literature search of medical databases and handsearching was undertaken to identify relevant studies. All studies were critically examined for quality using the CASP critical appraisal tool. Results from eight studies were combined and interpreted using a narrative synthesis. Findings A clear outline of common stress fracture appearances using ultrasound were identified in a combined total of 119 participants. Each finding was ranked according to its popularity. Periosteal thickening (78/119) and cortical disruption/irregularity (83/119) were noted in all eight studies. Hypervascularity of the periosteum visualised by colour Doppler imaging (66/119) was reported in six of the eight studies. Soft tissue hypervascularity (13/119), bony callus formation (5/119) and cortical break (22/119) were seen in three studies. Conclusions Based on the findings, we offer a guideline of the most significant preliminary image findings to be utilised by operators when examining athletes suspected of having lower limb stress fractures. The results show a gap in research for evaluating changes in appearance depending on the injury severity. Further research into distinguishing stress fractures from pathological involvement may in future reduce reliance on plain film radiography.

Comparative use of ultrasound and radiography for the detection of fractures: a systematic review and narrative synthesis

“…Three studies revealed bone callus development (5/119), soft-tissue hypervascularity (13/119), and break in cortex (22/119). The review also concludes that future work on separating stress fractures from pathological involvement might help to lessen the need for plain film radiography 22 .…”

“…In stress fractures, US have demonstrated more sensitivity than specificity except in trabecular stress fracture where it cannot evaluate subcortical bone 1 . US findings can also reveal different stress fractures findings along the lower limb which are otherwise invisible in plain radiographs but this requires further evaluation performed using larger multi-centre investigations on stress fractures diagnosis 22 .…”

Comparing Ultrasonography With Plain Radiography in the Diagnosis of Long Bone Fractures

“…Similarly, MRI cannot be used as the primary imaging technique primarily because of the increased cost and prolonged imaging time, despite its excellent sensitivity and specificity. 5,18 Although radiography is used as the diagnostic gold standard for detecting skeletal fractures, it does have certain limitations. Radiography employs low-dose ionizing radiation which may be contraindicated for some patients.…”

“…Similarly, MRI cannot be used as the primary imaging technique primarily because of the increased cost and prolonged imaging time, despite its excellent sensitivity and specificity. 5,18…”