Stress Fractures

Abstract

1.1 Rationale of application

X-ray-free direct representation of the connective tissue structures over a suspected fracture for the detection of direct or indirect signs of a stress fracture.

1.2 Level of evidence

III.

1.3 Indication

For the representation of the bone surface and the connective tissue structures above the bone if a stress fracture is suspected, especially if no diagnosis is possible on the X-ray image.

1.4 Age of the patient

Every age.

1.5 Contraindication

No.

1.6 Examination

Visualisation of the area suspected of fracture with high-resolution transducers (12–18 MHz), the transducer is placed at the point of greatest pain and always parallel to the axis of the bone. It is important to ensure that the cortical reflex is displayed most sharply. The transducer must be guided around the bone in parallel so that a suspected fracture cannot be overlooked if it is oblique. In addition to a cortical disruption, a periosteal thickening, lymphedema in the subcutaneous tissue and an inflammatory reaction in the power doppler are also to be found. If the cortical disruption is negative, the examination must be repeated after 7 days.

1.7 Indications for additional X-ray diagnostics

When detecting a stress fracture, a second imaging procedure should be used, preferably magnetic resonance imaging as the “golden standard” (Ammann et al. 2014) or X-ray to exclude other types of pathological fractures.

1.8 Pitfalls

Intraspongious stress fractures without an interruption of the cortex can be evidenced by ultrasound, here a change in the sound of the cortex with the extinction of the reverberation artifacts is to be sought (see Fig. 23.3).

1.9 Red flags

Pain in the femoral neck area with a suspected stress fracture should prompt be examined by magnetic resonance imaging because a dislocation is to be feared and ultrasound cannot reliably show the suspected fracture.