Fractures of the manubrium sterni: treatment options and a possible classification of different types of fractures

Abstract

Background: Sternum fractures are mostly located on the sternal corpus, seldom on the manubrium. Fractures of the sternal manubrium are, however, more frequently associated with severe concomitant injuries of thoracic organs, and therefore deserve special attention. In addition, in its function as a capstone in between the anterior chest wall and the shoulder girdle, it is exposed to a multiplicity of forces. Therefore the questions arise what types of fractures are observed in today's clinical practice, how to classify them and which treatment options are available. This study reports on different types of fractures which involve the manubrium sterni.

Methods: Between January 2012 and October 2014, data was collected from all severely injured patients (ISS ≥16), which received a CT scan of the thorax in our Level-I-Trauma Center and retrospectively analyzed concerning sternal fractures. Fracture type, collateral injuries, age, and information about the circumstances of the accident were noted.

Results: Of 890 evaluable patients, 154 (17.3%) had a fracture of the sternum and 23 (2.6%) of the manubrium. Fractures of the manubrium appeared in following types: A-type-transverse fracture (n=11) in 1st intercostal space by direct blunt trauma or flexion of the torso with sagittal instability; B-type-oblique fracture (n=9) by seat belt injury with rotatory instability; C-type-combined, more fragmentary fracture (n=3) by direct blunt trauma with simultaneous flexion of the torso and multi directional instability. Fractures only little dislocation were treated conservatively, and unstable fractures were surgically stabilized (n=10).

Conclusions: In summary, three main types of fractures could be found. A-type fractures were stabilized with a longitudinal plate osteosynthesis and B-type fractures with transverse positioned plates. To treat complex C-type fractures, plates with a T- or H-form could be a good solution. Level of evidence: Level III retrospective prognostic cohort study.

Keywords: Sternum fracture; anterior chest wall; classification; manubrium fracture; sternal fracture.

Figure 1

Population. About 14.9% out of the sternum fractures involved the manubrium, thereunder 47.9% transverse fractures, 39.1% oblique fractures and 11% combined fractures.

Figure 2

X-ray findings in Manubrium fractures (CT-scan). Three planes of imaging (multiplanar reconstruction, MPR) are necessary to evaluate the fractures of the manubrium sterni: the axial view shows the rotational instability in B- and C-type fractures, as well as horizontal splits in some transverse fractures. The sagittal view shows the sagittal instability in A- and C-type fractures. In severe dislocation the displaced part of the sternum might be non-visible in B-type fractures. The coronal view shows transverse fractures (A) as wells the oblique (B) and the combined (C) ones. The 3D-reconstruction shown as a volume rendering view gives a clear overview of the fractures’ topography.

Figure 3

Different types of manubrium fractures. A-type shows transverse fracture and sagittal instability of the trunk. Unstable fractures are best treated with longitudinal plating. B-type shows oblique fracture and rotatory instability of the shoulder girdle. Unstable fractures are best treated with transverse plating. C-type shows combined instability. Unstable fractures need to be stabilized in both directions—sagittal and coronal. Either a combination of transverse and longitudinal plates could be employed or special plates, e.g., in T or H-shaped forms.