Multilevel Spinal Fusion: Surgery, Risks, and Recovery

Multilevel fusion surgery

Techniques involved in multilevel spinal fusions are similar to those of single-level fusions for degenerative disc disease. The ‘menu’ of potential surgical approaches, bone graft options, and cage and instrumentation possibilities are the same as for one level fusions. This includes posterior approach only, anterior approach only, or a combined anterior and posterior approach surgery, which is more common in multilevel fusions. Most multilevel fusion procedures involve the use of spinal instrumentation in the back of the spine, but may also include supplemental anterior fixation as well.

The addition of multiple levels in the surgery increases the complexity of the procedure somewhat and also increases the risks compared to single-level fusion surgery. Potential problems with blood loss, arterial and venous thrombosis, and post-operative wound infections are directly related to the length of surgery, and multilevel procedures generally take longer than single-level fusions. However, the risks are not directly additive; a two-level fusion does not have twice the risk of a one-level fusion, but only a few percent increase in risk.

Preoperative considerations in multilevel fusion surgery relate to the larger size of the operative procedure. Consideration is usually given to preoperative blood donation, to have the patient’s own blood available for transfusion if needed due to the higher blood loss commonly associated with multilevel procedures. One unit of donated blood may be all that is needed if expected blood loss is minimal, and up to 3 units may be recommended in some larger reconstructive procedures. For larger anterior procedures and in high risk patients with a history of blood clots (deep venous thrombosis (DVT) or pulmonary embolus (PE)), use of a preoperatively placed removable filter into the Inferior Vena Cava (IVC filter) may be worth the added risk of the procedure in order to minimize the risk of a postoperative DVT or PE. These issues should be discussed with the treating surgeon as part of the preoperative discussion of surgical risk and ways to minimize these risks.

Recovery after multilevel fusion

Postoperative considerations include a longer recovery overall than for a one-level fusion, as would be expected due to the larger procedure overall. Depending on the surgical technique used, recovery still may be fairly quick, such as 6 to 8 weeks with the use of minimally invasive techniques. When multilevel fusion is done as a large reconstruction for spinal deformity (such as from scoliosis or scheuermanns kyphosis) over 4 levels or more, it can easily take the patient 6 months or more for maximal recovery.

With multilevel fusion procedures, use of a postoperative external brace is common, providing added support and limiting excessive motion of the low back. Use of rigid internal fixation (rods and screws) and interbody fusion support may obviate the need for a postoperative brace, even in a multilevel fusion, especially if a patient’s bone quality is strong.

Longer term issues to consider in multilevel fusion surgery include the risk of failure of fusion (also known as nonunion or pseudoarthrosis), as well as the theoretically higher risk of adjacent level degeneration.

• Fusion failure of one or more levels in multilevel fusion surgery can occur in as high as 40-50 percent of cases, and is highly dependent on patient risk factors and the surgical technique used. Patient risk factors for fusion failure include being a smoker, history of osteoporosis, and history of prior fusion failure. Surgical techniques to enhance fusion rate include interbody and posterior combined fusion, use of patient’s own iliac crest (pelvic) bone graft, and use of growth factors such as BMP-2 or OP-1. Again, the specific surgical technique used and risk of nonunion are subjects for the in-depth preoperative surgical discussion every surgical patient should have with their surgeon.

• Mobile spinal levels surrounding a spinal fusion see additional stresses when motion is restricted across the fusion. While it has not been proven, this additional stress is felt to contribute to a higher incidence of degeneration of adjacent segments, which could result in symptoms and the need for additional surgery in the future. This is known as ‘adjacent segment disease’. The stress seen by an adjacent level and risk of adjacent segment disease is felt to be progressively higher with more and more levels stiffened by fusion. Therefore, it is thought that multilevel spinal fusions may have a higher risk of adjacent segment disease than single level fusions.

While multilevel spinal fusions are a common and necessary procedure to treat many types of spinal surgical pathology, such as scoliosis or other types of deformity, for treatment of low back pain from degenerative disc pathology this type of procedure remains controversial. For two-level rigid fusions, a full discussion between the patient and spine surgeon should include the reason for the need for multilevel surgery, the added risks, and the surgical technique options in order to minimize risk and maximize chances for relief of symptoms and complete recovery. A fusion of three or more levels of the spine for painful multilevel degenerative disc disease is rarely, if ever, advisable. Patients who may be considering this option should exercise extreme caution by proactively researching all their non-surgical options and seeking additional surgical and non-surgical opinions.

• Article written By:
• Jeffrey M. Spivak, MD

August 31, 2007

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