Prosthetic Disc Nucleus (PDN) Replacement for Lumbar Disc Herniation

Abstract

A clinical follow-up study was performed to evaluate lumbar disc nucleus replacement clinically and functionally. The objective was to assess the clinical efficacy of the prosthetic disc nucleus (PDN) for treatment of lumbar disc herniation. The PDN was designed to treat patients suffering from disc herniation and/or degeneration. Clinical trials for PDN were first conducted in 1996, and the results showed that the PDN device was effective in most of the patients who were implanted. These studies had been carried out with patients who were implanted with a pair of the devices. The main complication was device migration. Therefore, a follow-up study based on a single PDN device implantation was designed to evaluate its clinical result. Forty-five patients with lumbar disc herniation were implanted with one PDN device from March 2002 to December 2002. Thirty (66.7%) patients came to the clinical, functional, and radiographic 6-month follow-up examinations. Independent analysis was performed by careful review of the charts, operative notes, preoperative and postoperative radiographs, magnetic resonance images, and follow-up records of all patients. After implantation, significant proportions of patients experienced pain relief. Improvements were noted in pain intensity, walking distance, lumbar mobility, neurologic weakness, Oswestry and Prolo scores, and intervertebral disc height. No difference in work status after PDN implantation could be detected. Compared with the preoperative height, the intervertebral disc had gained 19.7% (P < 0.001). Device migration, failure, and dislocation were not noticed in any patient. A few patients had minor complications such as transient low-grade fever. Clinically, a single PDN is preferred and can effectively increase the height of the intervertebral disc in patients with lumbar disc herniation. However, longterm follow-up of PDN implantation needs to be studied.

Numerical analysis of the influence of nucleus pulposus removal on the biomechanical behavior of a lumbar motion segment

“…At present, surgical management of lumbar disc herniation often involves removing the gel-like nucleus pulposus (NP) from the IVD (Gibson et al 1999;Jin et al 2003). However, NP removal can give rise to subsequent changes in disc geometry and loading responses (Bao et al 2002;Bertagnoli et al 2005), which may induce further protrusion of the IVD.…”

Biomechanical comparison between fusion of two vertebrae and implantation of an artificial intervertebral disc

“…For fusion, good outcomes are reported in 49-88% of the cases (Fritzell et al, 2003;Hanley and David, 1999;Madan et al, 2003 1999). For implantation of an artificial intervertebral device, good outcomes are reported in 50-99% of the cases (Guyer and Ohnmeiss, 2003;Jin et al, 2003;Kleuver et al, 2003). Nevertheless, multiple and diverse complications are observed.…”

Biomechanical function of a balloon nucleus pulposus replacement system: A human cadaveric spine study

“…However, the risk of device migration or extrusion has been described as a major issue to be addressed for a successful DNR. Another potential risk would be the subsidence of DNR device particularly with a small contract area between the device and the vertebral bodies . As a result, the introduced devices for DNR eventually cannot maintain the restored disc height, foraminal area, and biomechanical segmental motions because of the device migration or extrusion, and deformations and fractures of the end plate caused due to stress concentration.…”