[Cervical disc arthroplasty (Prodisc-C): analysis of 3 to 4- year follow up results].
OBJECTIVE
The aim of this study was to assess the heterotopic ossification rate (HO), the range of motion of the operated, as well as the adjacent segments and the clinical condition of patients following cervical arthroplasty over a medium-term period.


METHODS
The entrance criteria for cervical arthroplasty (Prodisc-C, Synthes, USA) included: clinical symptoms of degenerative disorders of the cervical spine-axial and radicular pain or radicular compromise and their corresponding signs on MRI-soft disc hernia or spondylosis. The prospective study included 16 patients of 30-63 years of age (mean age 47.44) and the follow up duration was from 3 years and 3 months up to 4 years (mean duration 44 months). The following parameters were assessed prior to the procedure and 3-4 years after the procedure: clinical condition (NDI), axial pain and radicular pain scores (VAS) and x-ray findings. Statistical tests were used to assess the outcomes.


RESULTS
3-4 years after the procedure, significant improvements in NDI by 48.13%, in cervical pain VAS by 65.75% and in radicular pain VAS by 67.31%, were demonstrated. All the above results were statistically significant. Arthroplasty improved sagittal balance of the cervical spine and the resulting lordosis of the operated segment was more pronounced. HO was detected in 56.25% of the operated segments and resulted in a complete loss of the arthroplasty mobility in 18.75% of the segments. No statistical significant differencies in rates of NDI, axial VAS and radicular VAS changes were found between patients with HO grade III and IV and patients with HO grade 0-II. No cases of the implant dislocation, subsidence or non-healing were observed, no subjects required surgical revisioning of the arthroplasty and no cases of "adjacent segment diseases" were recorded.


CONCLUSIONS
based on the current literature data, complete disc replacement results in clinical outcomes, which are similar to those in patients with segment fusion. However, statistically significant reduction in rates of surgical revisions, reoperations and additional fixations was observed in subjects with arthroplasty. HO and spontaneous arthroplasty fusion is a new phenomenon, which may have a negative impact on the potentially saving effect of the arthroplasty on its adjacent segments.


CONCLUSIONS
39-48 months following the Prodisc-C implantation, the below findings were demonstrated: 1. Statistically significant improvement in NDI by 48.13%, improvement in cervical pain VAS by 65.75% and radicular pain VAS improvement by 67.31%. 2. Arthroplasty resulted in improved sagittal balance of the cervical spine and the resulting lordosis of the operated segment was more pronounced. 3. HO was detected in 56.25% of the operated segments and resulted in a complete loss of the arthroplasty mobility in 18.75% of the segments. 4. No cases of the implant dislocation, subsidence or non-healing were observed, no subjects required surgical revisioning. 5. No cases of "adjacent segment diseases" were recorded.
Hrabálek
L
L
Neurochirurgická klinika FN a LF UP Olomouc. lumir.hrabalek@seznam.cz
Vaverka
M
M
Houdek
M
M
D000328:Adult; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis; D009999:Ossification, Heterotopic / Q000175:diagnosis / Q000209:etiology; D010147:Pain Measurement; D011183:Postoperative Complications; D019736:Prostheses and Implants / Q000009:adverse effects