Case 1
A 40-year-old man in a traffic accident was transported to our hospital. He was in a state of shock due to multiple trauma. The anatomical severity according to the Injury Severity Score was 26 points; the physiological severity according to the Revised Trauma Score was 7.10; and the probability of survival according to the Trauma and Injury Severity Score calculated from these values was 95.8% [4,5,6]. Bone computed tomography (CT) showed a highly displaced transverse sternal fracture (Fig. 1A, B) and rib fracture. Paradoxical breathing, i.e., flail chest, became apparent with spontaneous breathing and tachypnea and hypercapnia made withdrawal of the ventilator impossible. A transverse sternal fracture with flail chest indicated surgical repair to withdraw ventilator support.
On the 5th day after the injury, we performed surgical repositioning and fixation of the sternum using the modified Robicsek technique combined with SternaLock® (Zimmer Biomet, Jacksonville, FL, US) plate fixation as described in the “Operative technique” section below. There was minimal blood loss. Due to the repositioning and stabilization of the sternal fracture, flail chest entirely disappeared, and the ventilator was successfully removed the day after the operation. A postoperative CT scan confirmed that the sternum was properly repositioned (Fig. 1C, D). Currently, 1.5 years have passed since the operation, and excellent fixation is still maintained (Fig. 1E, F).
Operative technique (Fig. 2)
A fracture line was found at the level of the 2nd lower intercostal margin (Fig. 2A), and the upper sternum was largely displaced posterior to the lower sternum. The intercostals on both sides were separated at the margin of the sternum. Care was taken so as not to injure the internal thoracic and intercostal arteries and veins, whose locations were confirmed by preoperative CT.
The modified Robicsek technique was performed as described previously [2], with some modifications. One end of a stainless-steel wire was passed between several ribs, across the fracture line, and the other end was passed through the contralateral rib. The ends of the wire were finally tied in front of the sternum. In this case, both ends of a stainless-steel wire were advanced via the 1st intercostal space and drawn out via the 4th intercostal space, alternating from the posterior side of the 2nd rib to the anterior side of the 3rd rib and back to the posterior side of the 4th rib (Fig. 2B, C), and were finally tied in front of the sternum at the 4th intercostal level (Fig. 2D). Subsequently, two stainless-steel wires were passed horizontally at the 2nd and 3rd intercostals (Fig. 2E). Next, the sternum was fixed with a 12-pin H-shaped SternaLock® plate. Last, the transverse wires were tied in front of the sternum (Fig. 2F). The parasternal longitudinal wires acted as struts to the transverse wires.
Case 2
A 70-year-old man developed rapidly progressive cardiogenic shock due to fulminant myocarditis, and cardiopulmonary support was immediately initiated by Ecpella, a combination of peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) and an Impella® (Abiomed, Danvers, MA, US) percutaneous left ventricular assist device. Those both were successfully discontinued within 2 weeks after the initiation. Bone CT showed a transverse sternal fracture (Fig. 3A, B), resulting from chest compression during cardiopulmonary resuscitation. Although this was not much of an issue during the ECMO support with the less breathing effort, paradoxical respiratory movement became apparent with spontaneous breathing after weaning from ECMO and tachypnea and tachyarrhythmia made it difficult to withdraw ventilator support. Flail chest was a limiting factor for cardiac and respiratory rehabilitation, which indicated surgical repair.
On the 21st day after the injury, the fractured sternum was surgically repaired using the same combination technique as Case 1. Briefly, a combination of the modified Robicsek technique and sternal plating with an 8-pin H-shaped SternaLock® was performed (Fig. 3C). In this case, pseudo-articularization had already started, and the fragments of the exposed sternum were entirely separated after thorough dissection around the fracture line. Although preoperative CT under the condition of internal fixation by ventilator support appeared a simple fracture (Fig. 3A, B), in fact, pseudo-articularization probably resulted in paradoxical respiratory movement. The separated fragments of the sternum were manually repositioned and the combination technique was applied. There was very little bleeding. After surgery, significant improvement of the breathing movement enabled facilitating cardiac and respiratory rehabilitation as heart failure treatment. Finally, we were able to withdraw ventilator support under stable hemodynamics and respiratory conditions. Sternal fixation played a role of severe heart failure treatment for this patient. A postoperative CT scan confirmed that the sternum was properly repositioned (Fig. 3D). Two years after surgery, the patient has now fully recovered and has resumed his normal daily activities.
