Disc prostheses can replace diseased discs or symptomatic disc protrusions that press nerve roots and/or the spinal cord in the neck area. With the help of an artificial disc, the original height of the intervertebral space can be restored and segment mobility of the cervical spine can be maintained.
A 37-year-old locksmith suffered severe pain in the right arm 8 weeks ago, which essentially did not improve despite the use of painkillers, but increased as soon as he bent his head to the right or backwards. In his job, good mobility of the cervical spine is important. He must regularly perform overhead work. In addition to the severe neck and shoulder pain, a numb feeling began over the last 2 weeks that extends from the forearm to the thumb. The right arm had already become weak, and this was especially the case when trying to lift something heavy as well as when bending his elbow.
The problem or cause is a cervical spine disc prolapse at the C5-C6 level (Fig. 1-2). Parts of the defective disc (nucleus pulposus prolapse) penetrate out from a tear in the disc’s fibrous ring (annulus) and press on the nerve root (Fig. 2 - green arrow). The nerve root is compressed from the front and impaired by the prolapsed disc, which explains the specific pattern of pain as well as the arm weakness (paresis of the biceps muscle), i.e. this is a case of C6 (right) nerve root compression syndrome with neurological deficits.
A possible alternative to fixation with a plate implant after the removal of the disc (decompression) to relieve the affected nerve root is the artificial disc (Fig. 3-5). Movable components made from approved materials maintain the mobility of the segment and cervical spine during bending, stretching, lateral bending and rotation.
At the same time, intervertebral cervical disc prostheses restore the original height of the disc space. General and specific contraindications should be considered. Therefore, intervertebral disc prostheses are not suitable for every patient. For the young man, however, it is the best solution. The pain improved immediately after the operation, and there was no need for a longer recovery period. The follow-up X-ray (Fig. 5) shows that segment mobility could be achieved without functional restriction up to the last control examination.