Percutaneous Posterior Stabilization of the Spine

We have demonstrated the use of computer assisted techniques for performing posterior spine stabilization in a series of in-vitro studies. The techniques are still under development but have undergone early laboratory verification. Registration is the biggest limitation of conventional IGS systems when attempting to use them for percutaneous implantation of pedicle screws. This can be overcome by palpating structures beneath the skin or by implanting special tracked fiducial arrays attached prior to CT-scanning. Visualization of the posterior elements and placement of bone graft can be performed using a combination of endoscopic and IGS techniques, and pedicle screws placed using percutaneous approaches. Assembly of the stabilization construct is performed by subcutaneously threading the rods onto top-loading screws. Four cadaver studies have shown good results and demonstrated the possibilities and difficulties of registration, pedicle screw placement, and construct assembly using the minimally invasive techniques.