[Dynamic posterior stabilization with the cosmic system].

OBJECTIVE

Stabilization of unstable motion segments with a stable but non-rigid implant system without an additional spondylodesis.

INDICATIONS

Neurogenic claudication with instability; discogenic pain; in combination with a fusion (hybrid technique); elongation of a preexisting fusion; second recurrence of a herniated disk.

CONTRAINDICATIONS

Increased instability; correction and reduction; instrumentation of more than three levels.

SURGICAL TECHNIQUE

Muscle-sparing approach to the posterior lumbar spine under anteroposterior and lateral image control. Use of special instruments with a slotted sleeve connected to the screw head for rod implantation. Alternatively: conventional midline approach with detachment of muscles from the posterior spine.

POSTOPERATIVE MANAGEMENT

Mobilization on the day after surgery. Limited physical activities and no work load for 6 weeks.

RESULTS

In 139 patients (77 females, 62 males, average age 55 years) with a follow-up of 2 years, Oswestry score improved from 49.0% preoperatively to 22.5% and VAS (visual analog scale) from 7.3 preoperatively to 2.5 after 2 years. No change of the lordosis. Eleven revisions (7.9%). Two broken screws (0.3%) and 17 screws (2.5%) with a radiolucent halo.