This is a retrospective study based on analysis real world data obtained from hospitals that have adopted use of Montage or Montage-CT for use following sternotomy. The analysis will report the post-operative use of analgesic medication (including opioids) and compare the use against a control group consisting of patients operated by the same surgeon concurrently or prior to adoption of Montage or Montage-CT for use in sternotomy closure.

Inclusion Criteria:

1. Male or female > 19 years of age.
2. Underwent non-emergent cardiac surgery (isolated coronary artery by-pass grafting and/or isolated valve surgery).
3. Full median sternotomy approach - with/without cardiopulmonary bypass.

Exclusion Criteria:

1. Recent CPR.
2. Previous cardiac surgery (redo sternotomy).
3. Emergency surgery (operative intervention within 24 hrs of assessment).
4. Chronic lung disease.
5. BMI > 40.
6. Use of sternal plate systems for closure.
7. Recent antiplatelet therapy.
8. Previous radiotherapy to the chest; receiving immunosuppressive therapy or have a current immunosuppressive condition.
9. Active systemic infection (.i.e: endocarditis).
10. Cognitive impairment (confusion, dementia, Alzheimers, current substance abuse).
11. History of malignancies within past year (except squamous or basal cell carcinoma of the skin that has been treated; no recurrence)
12. Recent history of drug or alcohol abuse.
13. Females who are pregnant, nursing or of childbearing potential who are not practicing a birth control method with high reliability.
14. Postsurgical life expectancy < 90 days in the opinion of the investigator.

14. Moderate or severe pectus deformity. 16. Participation in another clinical trial. 17. Patients who had Patient-Controlled Analgesia (PCA) devices after surgery. 18. Patients who received a local anesthetic treatment and/or device on the sternum intraoperatively during surgery (e.g. On-Q Pain Relief System, Exparel etc)

Males and females age > 19 years of age who have undergone non-emergent cardiac surgery (coronary artery by-pass grafting [CABG] and/or single valve replacement procedure).