<br>        Inclusion Criteria:<br><br>          -  Indication for monosegmental anterior cervical discectomy with implantation of a disc<br>             prosthesis<br><br>        Exclusion Criteria:<br><br>          -  Radiologic signs of extensive bone degeneration in the affected segment<br><br>          -  Necessity of implantation of a device smaller in height than 5 mm (as predicted with<br>             teh use of the Vertaplan (TM) software<br><br>          -  Transversal spine cord lesion<br><br>          -  Cervical myelopathy<br><br>          -  Preceding surgery on the cervical spine<br><br>          -  Traumatic lesions of the cervical spine<br><br>          -  Radiographic instability in the affected segment: flexion / extension: shift sagittal<br>             plane> 3.5 mm or 20% and rotation in the sagittal plane > 20 °, OR in static X-ray<br>             examinations: shift in the sagittal plane 3.5 mm or 20% of the vertebral body width<br>             and relative sagittal plane angulation > 11º<br><br>          -  signs of instability (Olisthesis) in another segment of the cervical spine<br><br>          -  Active systemic infection<br><br>          -  diseases of the rheumatic type and all autoimmune diseases<br><br>          -  bone metabolic diseases (for example, Paget's disease)<br><br>          -  skeletal metastases<br><br>          -  infections in the cervical spine<br><br>          -  Neurological seizure disorders or other serious neurological disease with risk of<br>             falls<br><br>          -  Severe heart failure (NYHA III-IV)<br><br>          -  Bleeding disorders or clopidogrel / coumarins - treatment<br><br>          -  Systemic use of corticosteroids for more than a month in the last 12 months<br><br>          -  Pregnancy<br><br>          -  Legally incompetent patient<br><br>          -  Lactation<br><br>          -  Deformity, anomalies, not fully developed skeleton<br><br>          -  Local tumor disease<br><br>          -  Pre-existing neurologic abnormalities or other shortcomings, such as a Parkinson's<br>             disease, diabetic neuropathy, multiple sclerosis, peripheral neuropathy<br><br>          -  Drug / drug or alcohol dependence<br>      ;<br>        Inclusion Criteria:<br><br>          -  Indication for monosegmental anterior cervical discectomy with implantation of a disc<br>             prosthesis<br><br>        Exclusion Criteria:<br><br>          -  Radiologic signs of extensive bone degeneration in the affected segment<br><br>          -  Necessity of implantation of a device smaller in height than 5 mm (as predicted with<br>             teh use of the Vertaplan (TM) software<br><br>          -  Transversal spine cord lesion<br><br>          -  Cervical myelopathy<br><br>          -  Preceding surgery on the cervical spine<br><br>          -  Traumatic lesions of the cervical spine<br><br>          -  Radiographic instability in the affected segment: flexion / extension: shift sagittal<br>             plane> 3.5 mm or 20% and rotation in the sagittal plane > 20 °, OR in static X-ray<br>             examinations: shift in the sagittal plane 3.5 mm or 20% of the vertebral body width<br>             and relative sagittal plane angulation > 11º<br><br>          -  signs of instability (Olisthesis) in another segment of the cervical spine<br><br>          -  Active systemic infection<br><br>          -  diseases of the rheumatic type and all autoimmune diseases<br><br>          -  bone metabolic diseases (for example, Paget's disease)<br><br>          -  skeletal metastases<br><br>          -  infections in the cervical spine<br><br>          -  Neurological seizure disorders or other serious neurological disease with risk of<br>             falls<br><br>          -  Severe heart failure (NYHA III-IV)<br><br>          -  Bleeding disorders or clopidogrel / coumarins - treatment<br><br>          -  Systemic use of corticosteroids for more than a month in the last 12 months<br><br>          -  Pregnancy<br><br>          -  Legally incompetent patient<br><br>          -  Lactation<br><br>          -  Deformity, anomalies, not fully developed skeleton<br><br>          -  Local tumor disease<br><br>          -  Pre-existing neurologic abnormalities or other shortcomings, such as a Parkinson's<br>             disease, diabetic neuropathy, multiple sclerosis, peripheral neuropathy<br><br>          -  Drug / drug or alcohol dependence<br>