Minimally invasive spine surgery system considerations

The three types of systems discussed may be compared in terms of several known advantages and disadvantages that tend to accompany use of these types of minimally invasive spine fusion surgery systems. Each system has a number of unique benefits and limitations.

• Radiation Exposure: The amount of radiation that the patient and surgeon are exposed to is a consideration, although it is more a function of surgeon experience with minimally invasive spine fusion systems than the specific system being used. This is because there is a steep learning curve associated with using any of these systems and surgeon experience with the system usually correlates with how long the spine surgery lasts.

• Incisions: The first two systems leave 2 scars of approximately 3-5 centimeters, one scar to the left and one to the right of the midline of the lower back. The third spine fusion surgery system leaves a total of three scars of approximately 1.5 centimeters on each side of the spine.

• Recovery: There are no published studies investigating differences between the systems in terms of recovery following spine fusion surgery. There is also no general agreement in the medical community as to whether or not use of the minimally invasive surgery systems actually reduces length of hospital stay, blood loss, post-operative pain, etc., or which system is best.

• Fusion versus Fixation: Performing a posterolateral spine fusion is routinely feasible with the first two systems. The third system so far has not been able to devise a technique for posterolateral fusion through the present system. Posterior interbody spine fusions are possible with all three systems, however the incision for the third system would need to be enlarged.

• Operative Time: The amount of surgeon experience is by far the most important factor in operative times rather than the specific spine fusion surgery system used. In general, posterior interbody fusions generally involve longer operative times than posterolateral fusions.

• Surgeon learning curve: Pedicle targeting is a difficult undertaking that is necessary for all three systems, and all of the minimally invasive spine fusion surgery systems require a steep learning curve for the surgeon to build the necessary skills and experience.

• Multi-level spine fusions: All of the systems allow multilevel fusions, but the ability to place pedicle screws at each pedicle when performing a two level fusion (known as segmental instrumentation, which may aid in long-term stability) is only possible with the first two systems. The third system involves skipping the pedicles at the middle level.

In general, most of the relative advantages and disadvantages of each minimally invasive spine fusion surgery system are still considered by most surgeons to be theoretical, as the specifics have not yet been proven one way or another.   For example, some surgeons feel that minimally invasive spine fusion systems result in smaller scars, which helps speed the recovery process, while other surgeons feel that one 6-8 cm incision creates less damage than two to three 1.5—5 cm incisions.