The Combined Use of a Posterior Dynamic Transpedicular Stabilization System and a Prosthetic Disc Nucleus Device in Treating Lumbar Degenerative Disc Disease With Disc Herniations

Abstract

BackgroundProsthetic replacement of spinal discs is emerging as a treatment option for degenerative disc disease. Posterior dynamic transpedicular stabilization (PDTS) and prosthetic disc nucleus (PDN) devices have been used sporadically in spinal surgery.MethodsThis was a prospective study of 13 patients averaging 40.9 years of age with degenerative disc disease who underwent posterior placement of a PDN with a PDTS. The Oswestry low-back pain disability questionnaire and visual analog scale (VAS) for pain were used to assess patient outcomes at the 3rd, 6th, and 12th postoperative months.Lumbar range of motion was evaluated using a bubble inclinometer preoperatively and at 12 months postoperatively. Radiological parameters including lumbar lordosis angle (LL), segmental lordosis angle (α), disc height at the operated level (DHo), and disc height of the adjacent level (DHu) were evaluated. A typical midline posterior approach for complete discectomy was followed by the simultaneous placement of the PDN with PDTS.ResultsBoth the Oswestry and VAS scores showed significant improvement postoperatively (P < .05). There were no significant differences in LL, α, DHo, and DHu parameters. We observed complications in 3 patients including 2 patients who had the PDN device embedded into the adjacent corpus; 1 had massive endplate degeneration, and the other experienced interbody space infection. In 1 patient, the PDN device migrated to one side in the vertebral space.ConclusionThe use of a PDN in combination with posterior dynamic instrumentation can help to restore the physiologic motion of the anterior and posterior column and could help to establish posterior dynamic instrumentation as an important treatment of degenerative disc disease. Theoretically this concept is superior, but practically we need more advanced technology to replace disc material. Because this study examined the combination of the PDN and stabilization instrumention, the results cannot be compared with those reported in the literature for either PDN alone or dynamic screws alone.Level of EvidenceProspective cohort study with good follow-up (level 1b).

Clinical outcomes of degenerative lumbar spinal stenosis treated with lumbar decompression and the Cosmic “semi-rigid” posterior system

“…In this system some of the load is shared and transferred by the system; therefore there is a reduction in stress-shielding effects on the bone. 63 , 64 Reduced stiffness helps the load distribution, and adjacent disc distance degeneration slows down. We observed no obvious degeneration on adjacent levels by MRI comparison preoperatively and postoperatively at 2 years’ followup; however, this observation does not mean that the system protects adjacent segments.…”

Dynamic Stabilization for Challenging Lumbar Degenerative Diseases of the Spine: A Review of the Literature

“…HydraFlex (Raymedica, Inc., Minneapolis, MN) is the last form of PDN [64]. There are some clinical studies regarding PDN, but the results of studies are not good [65, 66]. It is used limitedly today [4].…”

“…Safinas hinged screw works similarly to cosmic screw and allows the limited motion in flexion and extention behavior of the spine, but it controls displacement rotation and translation. There are some both clinical [37, 44, 47–50, 52, 66, 89] and biomechanical [25, 39, 86, 88] studies about dynamic screw-rod stabilization system.…”

Motion-preserving technologies for degenerative lumbar spine: The past, present, and future horizons

“…Pain relief has been reported with the PDN at 6 months and 1 year of followup. 23 , 24 However, migrations have continued to occur 25 with disc herniations. Raymedica has reported that over 4,000 patients worldwide have received either the PDN or a PDN-SOLO implant.…”