Unexpected results after sternal reconstruction with plates, cables and cannulated screws

Abstract

Objectives: During the last decade, various plate fixation systems have been developed for the treatment of complicated sternal dehiscence after open-heart surgery. One of them is the Modular Sternal Cable System© (MSCS), which promises optimal distribution of forces along the whole sternum by using plates, cannulated screws and cables. However, in comparison with other systems, there is a lack of outcome data.

Methods: Sternal reconstruction with the MSCS was performed in 11 patients (male n = 10, age 72.0 ± 7.3 years) with complicated sternal dehiscence following cardiac surgery, and 73% of them had a history of sternal infection. Sternal reconstruction included bilateral longitudinal plating and thoracic re-closure with 4-9 cables. Patients received postoperative examination, focusing on sternal wound conditions and clinical stability. If there was any suspicion of recurrent wound infection, computed tomographic scans were done in the early postoperative period or in the long term, in order to evaluate bony consolidation and integrity of osteosynthetic material.

Results: The mean operation time was 165 ± 59 min, the mean intubation time 4.7 ± 5.3 min and the mean intensive care unit length of stay was 1 day (median) (range 1-23 days), with a total hospital stay of 9 days (median) (range 5-64 days). Operative mortality was 0%. One patient died on the 65th postoperative day of a non-MSCS-related cause. Sternal wound infection occurred in 6 patients (54.5%) and made hardware removal necessary in 5 of them early postoperatively (median 14 days) and in 1 patient late postoperatively (1058 days). In another patient, material was removed 715 days after MSCS application due to persisting sternal pain.

Conclusions: A high incidence of postoperative wound infections was observed after implantation of the MSCS. It may be speculated that hardware design (e.g. the absence of a locking system, large screws) compromises osseous microcirculation, favouring the development of infection. This should be kept in mind for further development of sternal reconstruction systems.

Keywords: Osteosynthesis; Rigid plate fixation; Sternal dehiscence.

Figure 1:

Operating principle of the MSCS using two plates, cannulated screws and cables (Courtesy of the German Heart Center Munich). MSCS: Modular Sternal Cable System.

Figure 2:

(A) Postoperative CT scan showing sternal separation. (B and C) Break in of all multifilament cables (Courtesy of the German Heart Center Munich). CT: computed tomography.

Figure 3:

(A) Sufficient sternal refixation using the MSCS. (B) Parasternal costal avulsion postoperatively (Courtesy of the German Heart Center Munich). MSCS: Modular Sternal Cable System.