In his latest installment to the Total Spine series of instructional videos, Dr. Paul McCormick describes retropleural thoracotomy, a surgical technique used to treat complex spinal conditions of the thoracic and lumbar spine. “Retropleural thoracotomy is an important...
Instrumented Spinal Fusion
|What is Instrumented Spinal Fusion?|
Instrumented = using instruments such as rods, plates, screws, cages, and hooks
Instrumented spinal fusion is a procedure in which a surgeon uses instruments such as rods, plates, and screws to help bones in the spine fuse, or grow together.
An instrumented spinal fusion is performed in adult or pediatric patients when the spine has been weakened by degenerative conditions, deformity, trauma, tumor, or surgery. The purpose of the procedure is to restore spinal strength so that the spine can withstand normal day-to-day stresses and can also protect the spinal cord and nerves against more excessive forces that are occasionally encountered.
The basic premise of a spinal fusion is the creation of a bone “bridge” that connects strong and healthy bone above the weakened spinal segment with strong and healthy bone below it. To build this bone bridge, the surgeon places bone graft, or small pieces of bone, across the span where fusion is desired. The graft may be taken from the patient’s own body (an autograft) or from a bone bank (an allograft).
There are proteins in the human body that encourage bones to grow and fuse; they naturally assist during the healing of a fracture. These proteins, called bone morphogenic proteins (BMPs), may also be used to encourage bones to grow together after a spinal fusion. In some patients, the surgeon may use bone substitutes, bone extenders, and biologics like demineralized bone matrix or hydroxyapatite to assist in strong bone growth.
In an instrumented spinal fusion, instruments–rods, plates, screws, cages, and/or hooks–hold the bones in place while they fuse. The instruments are generally made of titanium, stainless steel, or cobalt chrome. Screws or hooks are inserted into the weakened vertebrae, as well as into adjacent healthy vertebrae. The screws or hooks serve as strong anchors to the spine. These anchors are then attached to metal rods that span the weakened segments, forming a metallic bridge. Forces can be applied to the rods to correct deformities and straighten the spine.
The metallic “bridge” formed by the instruments provides immediate strength and stability to the spine, but it is not a long-term solution. The instruments will never be as strong as on the day they are implanted. Normal activities of everyday life may strain them, and eventually the instruments may fail. Long-term spinal stability is best achieved with good fusion of the bones. The process of bone fusion takes several months–up to a year or more for patients with fusions that extend over several spinal segments.
When good fusion is achieved, the instruments are no longer necessary. However, they are usually left in place to avoid additional surgery. (In the few cases where good fusion is not achieved, the surgeon evaluates the specific case and forms an individualized plan for further treatment.)
|When is this Procedure Performed?|
An instrumented spinal fusion may be performed to treat mechanical pain (pain from a moving joint) or for conditions or surgical procedures that would otherwise compromise spinal stability.
Like any other surgery, an instrumented spinal fusion has its pros and cons. When compared with a non-instrumented spinal fusion, an instrumented spinal fusion has some clear benefits and some potential drawbacks.
Benefits of instrumented spinal fusion include:
Potential risks of instrumented spinal fusion include:
|How is this Procedure Performed?|
This procedure is performed under general anesthesia, which means the patient is unconscious and can not feel pain during the procedure.
|How Should I Prepare for this Procedure?|
Make sure to tell your doctor about any medications that you’re taking, including over the counter medication and supplements, especially medications that can thin your blood such as aspirin. Your doctor may recommend you stop taking these medications before your procedure. To make it easier, write all of your medications down before the day of surgery.
Be sure to tell your doctor if you have an allergy to any medications, food, or latex (some surgical gloves are made of latex).
Nicotine significantly affects how the bones will fuse after the procedure. For the best chance at a positive outcome, stop using tobacco well before surgery. If you currently smoke or use other tobacco products, speak to your neurosurgeon about quitting.
|What Should I Expect After the Procedure?|
In properly selected patients spinal fusion is associated with excellent outcomes; over 90 percent of patients achieve a solid fusion and derive significant benefit from the surgery.
To increase the likelihood of a successful fusion, the surgeon may look to eliminate or reduce risk factors that may increase the probability of a failed fusion. Smoking, poorly controlled diabetes, chronic steroid use, anti-inflammatory medications (e.g. aspirin) or other therapies that reduce the body’s immune or anti-inflammatory response may increase the risk of a failed fusion, also called a non-union or pseudoarthrosis. Periodic X-rays or even CT scans are performed after surgery to assess the progress of the bone fusion.
|Preparing for Your Appointment|
Drs. Paul C. McCormick, Michael G. Kaiser, Peter D. Angevine, Alfred T. Ogden, Christopher E. Mandigo, Patrick C. Reid and Richard C. E. Anderson (Pediatric) are experts in instrumented spinal fusion.
Helpful Surgery Overviews
Dr. McCormick will choose the treatment method specific to each patient and situation. Some of the condition’s treatment options may be listed below.
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