A sternotomy is a common surgical procedure involving a vertical incision through the breastbone (sternum) to access the heart, lungs, or major blood vessels. This technique is routinely used for procedures like coronary artery bypass grafting and heart valve repair. To ensure the breastbone heals correctly after being divided, patients must strictly follow post-surgical guidelines known as sternal precautions. These temporary activity restrictions are designed to protect the healing bone and prevent serious complications, establishing a stable foundation for long-term recovery.
Understanding the Need for Sternal Precautions
The sternum is a flat, dagger-shaped bone located in the center of the chest, connecting the ribs and protecting the heart and lungs. During a median sternotomy, this bone is carefully cut down the middle and then reconnected, typically using surgical stainless steel wires, which function much like a strong internal splint. The body must then work to achieve what is called a bony union, where the two halves of the bone fuse back together through a natural process of bone healing.
The chest wall is constantly in motion with every breath, cough, or sneeze, creating forces that pull on the healing sternum. If excessive force or strain is placed on the breastbone before fusion is stable, it can lead to sternal dehiscence, which is the separation of the sternal halves. Preventing this separation is the primary goal of sternal precautions, as dehiscence causes pain, instability, and an increased risk of deep wound infection. The initial phase of fibrous tissue forming between the bone segments begins within the first few weeks, but this connection remains fragile and susceptible to disruption.
The Standard Duration of Restrictions
The standard duration for following sternal precautions is six to eight weeks following surgery. This timeline is based on the average period required for the sternum to achieve a stable, fibrous union, gaining approximately 50 to 60 percent of its final strength. While this initial period restricts activity, complete bone remodeling and full strength recovery continues for three to six months.
The specific duration can vary between individuals, as sternal healing is influenced by several factors. Advanced age, pre-existing conditions like diabetes, obesity, poor nutrition, and smoking can slow the bone-healing process. The surgical technique used for sternal closure is also a factor. The final determination for lifting the precautions must always come from the surgical team or cardiac rehabilitation specialists, who assess individual progress and risk factors.
Key Activities to Avoid During Precautions
During the six-to-eight-week precaution period, patients must adhere to restrictions to minimize strain on the breastbone. The most common restriction involves lifting, where patients should not lift anything heavier than five to ten pounds. This weight limit is often compared to a gallon of milk or a small bag of groceries, and it includes not lifting children or heavy pets.
A second category of restrictions focuses on arm movements that can pull the sternum apart. The general rule is to keep the elbows close to the sides of the body when moving or performing daily tasks. This restriction also applies to pushing and pulling motions. Patients must avoid:
- Reaching both arms overhead.
- Reaching behind the back or too far across the body.
- Using arms to push up from a chair or bed.
- Pulling open heavy doors or pushing a vacuum cleaner.
Driving is also restricted, usually for the first four to six weeks post-surgery. This restriction is enforced due to the physical strain required to turn the steering wheel and the potential risk of sudden airbag deployment. The ability to react quickly in an emergency, which requires sudden, forceful arm movements, is also impaired while the sternum is healing.
Safe Return to Full Activity
Once the six-to-eight-week period has passed, the transition back to full activity must be gradual and requires formal clearance from the surgeon or cardiologist. The sternum is considered sufficiently stable at this point, allowing for a progressive increase in physical exertion. A structured cardiac rehabilitation program is often the safest and most effective way to manage this transition.
Cardiac rehab provides a supervised environment for patients to slowly reintroduce previously restricted activities. Activities like swimming, light gardening, or golf can be resumed, but only with a measured approach to monitor the body’s response. The focus of recovery shifts from protecting the sternum to improving overall cardiovascular fitness and endurance, which may still be reduced. Even after the sternum has stabilized, patients are advised to continue avoiding heavy resistance training or strenuous, asymmetric movements for several months to ensure complete bone remodeling.