After a median sternotomy, the breastbone is expected to heal back together much like any other fractured bone. Occasionally, though, the two halves separate before healing is complete — a complication known as sternal dehiscence. Understanding why this happens, who is more likely to experience it, and how surgical teams work to reduce the risk can help patients and clinicians alike approach recovery with realistic expectations. This article reviews the clinical picture of sternal dehiscence and the prevention strategies commonly discussed in cardiac surgery literature.
What Is Sternal Dehiscence?
Sternal dehiscence refers to a partial or complete separation of the sternum along the surgical closure line following a sternotomy. It can occur early, within the first few weeks after surgery, or later during the healing process. In some cases the skin and soft tissue remain intact while the bone itself has separated; in more severe presentations, the wound edges open as well. Reported incidence in cardiac surgery literature varies, but it is generally described as an uncommon though clinically significant complication that surgical teams actively monitor for during the postoperative period.
What Causes Sternal Dehiscence?
Multiple factors can contribute to failure of the sternum to heal and remain stable. Commonly cited contributors include:
- Patient-related factors: obesity, diabetes, osteoporosis, chronic obstructive pulmonary disease, and prior chest irradiation are frequently discussed as factors that can affect bone quality or wound healing capacity.
- Mechanical stress: repetitive strain on the chest wall from coughing, lifting, or certain arm movements before the sternum has consolidated.
- Infection: a deep sternal infection can compromise the integrity of the bone and surrounding tissue, weakening the closure and increasing the likelihood of separation.
- Technical and fixation-related factors: how the sternal halves are approximated and secured during closure is considered one of the modifiable variables surgical teams can influence.
No single factor explains every case, and dehiscence is generally understood as arising from a combination of biological and mechanical variables rather than one isolated cause.
How Is Fixation Choice Connected to Sternal Stability?
Traditional sternal closure has long relied on stainless steel wires passed around or through the sternum and twisted to hold the two halves together. In recent decades, plate-and-screw fixation systems, including titanium sternal fixation plate systems, have become part of the surgical toolkit for certain patients, particularly those considered at higher risk of poor bone healing. The underlying principle behind rigid plate fixation is to distribute mechanical load more evenly across the closure and to limit micromotion between the sternal halves during the early healing window. Fixation choice is one of several variables a surgical team weighs alongside patient anatomy, bone quality, and institutional protocols — it is not a universal solution, and the appropriate method is determined case by case by the operating surgeon.
Who Is Considered at Higher Risk?
Cardiac surgery literature commonly identifies certain groups as having a higher reported likelihood of sternal wound complications, including sternal dehiscence. These groups often include patients with poorly controlled diabetes, significant obesity, chronic steroid use, osteoporosis, bilateral internal mammary artery harvesting, and those undergoing reoperative sternotomy. Older age and reduced bone density are also frequently mentioned as contributing considerations. Recognizing these risk categories allows surgical teams to plan closure technique, postoperative activity guidance, and monitoring more carefully for individual patients.
What Are the Warning Signs Patients Should Know?
Patients recovering from sternotomy are generally advised to be alert for specific symptoms that may indicate a healing problem. These commonly include a clicking, popping, or grinding sensation in the chest with movement, visible or felt instability of the breastbone, new or worsening wound drainage, redness or warmth around the incision, fever, or increasing chest pain unrelated to normal postoperative soreness. Any of these findings should prompt the patient to contact their surgical team promptly or seek immediate medical care, since early evaluation supports timely management.
Can sternal dehiscence be prevented entirely?
No approach eliminates risk completely, since dehiscence results from a mix of patient biology and mechanical factors. Surgical teams reduce risk through careful patient assessment, appropriate closure technique, and clear postoperative activity guidance, but individual outcomes vary and suitability of any approach is determined by a qualified physician.
Is sternal dehiscence the same as a sternal infection?
Not necessarily. Dehiscence describes physical separation of the bone, while infection refers to a separate process involving bacterial contamination of the wound or bone. The two can occur together, since infection can weaken tissue and contribute to separation, but a patient can experience one without the other.
How soon after surgery does dehiscence typically appear?
It can present at different points during recovery, though many cases are identified in the early postoperative weeks while the sternum is still consolidating. Any concerning symptoms should be reported to the surgical team regardless of how much time has passed since the operation.
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