The rationale of considering TDR rather than a standard fusion procedure (i.e. ACDF) lies in the aim of preserving motion of the treated segment and preventing adjacent-segment degeneration. The typical candidate patient for TDR is the young active adult patient with single level symptomatic disc disease (i.e. radiculopathy) from C3 to T1 with intact posterior facet joints. General contraindications are marked reduction of the disc space with loss of motion at that level, zygapophyseal joint osteoarthritis, significant deformity in the sagittal and coronal plane, clear segmental instability, and infection. Other relative contraindications include rheumatoid arthritis, renal failure, osteoporosis, cancer, and preoperative corticosteroid use [20].

Evaluation of sagittal alignment, presence of zygapophyseal joint osteoarthritis and instability is of paramount importance and should be undertaken as routine preoperative assessment in every patient. Standard X-ray films (i.e. AP and lateral view) of the cervical spine and flexion-extension studies are usually sufficient in clarifying the extent of residual movement at the index level and the presence of osteoarthritic changes in the posterior joints.

The role of TDR in patients with axial neck pain has not been clarified yet and therefore disc pathology with no neurological symptoms should not be considered an indication for TDR. European and US trails have enrolled patients with cervical radiculopathy due to disc herniation (soft or hard), foraminal osteophytes as well as cervical myelopathy. In our clinical experience the presence of a hard disc herniation should be considered a relative contraindication to TDR due to frequent need of a more extensive disruption of the endplate for a satisfactory clearance of the canal. In both European and North American trials, there has been a strong prevalence of patients enrolled with radiculopathy (77–93 %) rather than cervical stenosis/myelopathy . The role of TDR in cervical myelopathy has been recently investigated by different authors. Sekhon and co-workers [21] from Australia reported on 11 patients with single level myelopathy treated with TDR and average follow-up of 18 months. Although significant improvement was reported in clinical outcome measures, two complications were noted. One patient developed heterotopic ossification, and another patient developed progression of myelopathic compression due to postoperative oedema . Moreover, worsening of sagittal alignment of the cervical spine was noted in three patients. On the other hand, other authors have reported their positive experience of TDR in myelopathic patients. Fay et al. [22] reported on the results of a comparative study of TDR in 151 consecutive patients with cervical radiculopathy and cervical myelopathy. At the average follow-up of 36 months, no differences were identified in the two groups in terms of clinical and radiographic outcomes . However in our opinion cervical TDR should be avoided in patients with cervical myelopathy. Complete clearance of the spinal canal and wide decompression of the spinal cord are top priorities in cervical myelopathy surgery and the achievement of a solid and stable fusion if the best single guarantee for a long term success of the decompression.

A summary of the most common indications and contraindications for cervical TDR is shown in Table16.1. Although a thorough discussion on the indications of TDR is not possible due to the recent introduction into clinical practice of this technique, indications and contraindications listed in the table are widely accepted by most authors.

Cervical disc replacement surgery shares with standard anterior cervical fusion surgery the same risks related to surgical approach. In a recent retrospective review by Fountas et al. of 1015 cases of primary one, two, and three level ACDF and plating, reported mortality was 0.1 %; 9.5 % of the patients suffered from postoperative dysphagia, 3.1 % had recurrent laryngeal nerve palsy, 2.4 % prevertebral hematoma, 0.5 % had dural perforation, 0.1 % hardware failure, and 0.1 % wound infection [32]. Access related complications for cervical arthroplasty are in the same range. In the two European studies on BRYAN disc, 0.97 % of patients (1 out of 103) required evacuation of prevertebral hematoma, and 2.91 % (3 out of 103) required additional surgery to decompress the neural canal. Dural tear was noted in 2.33 % of patients, and one patient required oesophageal tear repair [23, 24]. Analysis of complications in one FDA IDE trail showed more general medical complications in patients who underwent total disc replacement than the fusion group. Dysphonia/dysphagia was noted in 10 % of patients in the arthroplasty group, and 2.8 % of patients developed wound infection [28].