PROPHYLACTIC RIGID PLATE FIXATION OF THE STERNUM FOR
HIGH-RISK PATIENTS
David H. Song, M.D.*, Robert F. Lohman, M.D.*, John D. Renucci, M.D.*, David Jayakar,
M.D.‡; and Valluvan Jeevanandam, M.D.‡
University of Chicago
Department of Surgery
Sections of Plastic and Reconstructive Surgery* and Cardiothoracic Surgery‡
Background: Sternal wound infection leading to post-operative mediastinitis is a devastating
complication of cardiac surgery carrying nearly a 15% mortality rate despite current treatment
methods. Contemporary techniques of sternal closure in attempt to prevent complications are all
based upon non-rigid methods of osteosynthesis. Instability of bone fragments predisposes a
patient to have non-union, mal-union and subsequent sternal wound infection during the process
of healing. In order to prevent instability, rigid plate fixation has been utilized for acquired and
surgically created fractures of virtually every bone in the body. While most fractures and
osteotomies benefit from rigid fixation techniques, the current standard for sternal osteotomy
closure remains the non-rigid method of circlage wires. Application of rigid plate fixation for
sternal osteotomies affords greater stability and thus a decreased opportunity for non-union, malunion and subsequent sternal wound infection to occur. A safe, efficient and effective technique
for rigid fixation of sterna is described.
Methods: Since July of 2000, rigid plate fixation has been applied to 45 patients designated
as having high risk for sternal dehiscence and subsequent mediastinitis. High risk was defined as
patients having 3 or more established historical risk factors, including: COPD, Re-Operative
Surgery, Renal Failure, Diabetes, Chronic Steroid Use, Morbid Obesity, Concurrent Infection
and Acquired or Iatrogenic Immunosuppression. Patients were selected by cardiac surgeons, and
rigid plate fixation was performed by a single plastic surgeon.
Results: Rigid plate fixation was performed on 26 males and 19 females. The average age of
patients was 63 (43-88) years. The average follow-up was 15 weeks (range 8 to 41 weeks).
While there were 4 peri-operative deaths unrelated to sternal closure: one from aspiration
pneumonia (postoperative day 9), one from a pulmonary embolus (postoperative day 29), one
from overwhelming sepsis from pre-existing endocarditis (postoperative day 15), and primary
respiratory failure (postoperative day 12). All others healed successfully. Finally, there was one
patient who had a sterile dehiscence who subsequently underwent successful re-operative rigid
fixation. Comparing the cohort of patients who received rigid plate fixation to a matched
population of high-risk patients during a similar time period who received wire closure, revealed
a significant difference in the incidence of post-operative mediastinitis. The wire closed group
(n=207) had 18 deaths unrelated to sternal closure and had 28 patients who developed
mediastinitis (14.8%). The rigid plate fixation group had an incidence of 0 (Fisher’s exact test
p=0.006). The total incidence of post-operative mediastinitis during the designated study period
was 4.2%.
Conclusions: The techniques of rigid fixation, first made popular in long bone fractures,
have been translated into virtually every bone in the body. Due to the proven merits of increased
stability and decreased incidence of non-union, mal-union and infection, the principles of rigid
fixation have caused paradigm shifts away from wire fixation of bone for maxillofacial surgeons
and more recently neurosurgeons. The merits of rigid fixation have been directly translated to
the sternum in a safe, efficient and effective manner. Patients who benefited from sternal closure
with rigid plate fixation showed a significant decrease in the incidence of post-operative
mediastinitis when compared to matched population of patients whose sterna were closed with
wire.
Figure 1
Plate fixation (Sternalock-Walter Lorenz Surgical) of the sternum immediately after coronary
artery bypass grafting.