Reversal of anterior cervical discectomy and fusion with cervical artificial disc replacement: regain motion after 9 years fusion

Treatment of cervical non-union with cervical disc replacement: A case series

Introduction

Cervical disc replacement (CDR) has become prevalent in the treatment of cervical pathology. CDR is an appealing option for several reasons, including improvement of symptoms, preservation of range of motion, and the absence of risk for nonunion – a complication of an anterior cervical decompression and fusion (ACDF) surgery. In this case series, we explore the use of CDR to treat cervical nonunion.

Methods

Four patients, ages 50 to 64, presented to one surgeon with symptomatic cervical nonunion. Three of the four patients possessed risk factors for further nonunion and were therefore considered especially well-suited to a CDR rather than a revision ACDF. X-ray, MRI, and CT were used to confirm the presence of nonunion and to determine the architectural feasibility of replacing the level with a cervical disc arthroplasty. Six total nonunion levels were present in four patients (two levels in two patients and one level in two patients). Each of the nonunion levels was successfully treated with a revision decompression and CDR.

Results

Postoperatively, all four patients experienced improvement of nonunion symptoms. Neck Disability Index improved on average by 75% (preoperative score 51% to postoperative score 13%). Flexion-extension X-rays were available in three patients, which showed an increase in an average range of motion from 2 degrees to 7 degrees at the revised levels.

Conclusion

The series describing four successful cases expands the current literature and provides support for future investigation into CDR as a treatment for cervical nonunion. We propose CDR as a viable option to treat symptomatic cervical nonunion and restore range of motion in patients without significant arthrosis and with preserved endplate architecture.

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Cervical disc replacement as an emerging treatment option for preserving motion

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Four patients with confirmed nonunion successfully received disc replacement.

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All resolved symptoms, measured by NDI, and regained range of motion.

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CDR as viable treatment option for nonunion repair

Clinical and radiological outcomes following hybrid surgery in the treatment of multi-level cervical spondylosis: over a 2-year follow-up

Background

The optimal surgical approach for treatment of multi-level cervical disc disease is currently widely debated. Anterior cervical discectomy and fusion (ACDF) combined with cervical disc arthroplasty (CDA) has been presented as a treatment approach, but to date, there are few reports with adequate clinical and radiological data for this hybrid surgical procedure. The goal of this paper is to assess clinical and radiological outcomes in patients with cervical spondylosis in three contiguous segments after treatment with artificial disc replacement combined with fusion.

Materials and methods

We performed a retrospective review of 36 patients (mean age of 48.6 years) with contiguous three-level cervical spondylosis who were treated with ACDF coupled with CDA (hybrid surgery) between October 2008 and October 2012. Clinical evaluation was based on the Neck Disability Index (NDI), Japanese Orthopaedic Association (JOA) score, and postoperative JOA score improvement rate (IR). Radiographic parameters, angular range of motion (ROM) for C2-C7, and ROM for the superior and inferior adjacent segments were measured before the operation, at 1, 3, 6, and 12 months postoperation, and at the final follow-up evaluation. All cases were followed for at least 28 months (range 28–65 months).

Results

All patients exhibited significant postoperative improvement in NDI and JOA scores compared to preoperative levels (P < 0.05), and these improved scores were maintained during the follow-up period. The JOA score improvement rate was 70.83 % at the final follow-up evaluation. The mean C2-C7 ROM of all cases was significantly decreased immediately after operation but recovered to preoperative levels after 12 months (P = 0.721). The ROM of the superior and inferior adjacent segments was recovered to preoperative levels after 6 months (P > 0.05). One patient required a second surgery for symptomatic adjacent segment degeneration. Neither pseudarthrosis nor other device migration was observed in any patients during the entire follow-up period.

Conclusions

These results indicate that hybrid surgery seems to be a promising, acceptable, and alternative surgical approach for the treatment of multi-level cervical disc disease.

Artificial disc and vertebra system: a novel motion preservation device for cervical spinal disease after vertebral corpectomy

OBJECTIVE

To determine the range of motion and stability of the human cadaveric cervical spine after the implantation of a novel artificial disc and vertebra system by comparing an intact group and a fusion group.

METHODS

Biomechanical tests were conducted on 18 human cadaveric cervical specimens. The range of motion and the stability index range of motion were measured to study the function and stability of the artificial disc and vertebra system of the intact group compared with the fusion group.

RESULTS

In all cases, the artificial disc and vertebra system maintained intervertebral motion and reestablished vertebral height at the operative level. After its implantation, there was no significant difference in the range of motion (ROM) of C(3-7) in all directions in the non-fusion group compared with the intact group (p>0.05), but significant differences were detected in flexion, extension and axial rotation compared with the fusion group (p<0.05). The ROM of adjacent segments (C(3-4), C(6-7)) of the non-fusion group decreased significantly in some directions compared with the fusion group (p<0.05). Significant differences in the C(4-6) ROM in some directions were detected between the non-fusion group and the intact group. In the fusion group, the C(4-6) ROM in all directions decreased significantly compared with the intact and non-fusion groups (p<0.01). The stability index ROM (SI-ROM) of some directions was negative in the non-fusion group, and a significant difference in SI-ROM was only found in the C(4-6) segment of the non-fusion group compared with the fusion group.

CONCLUSION

An artificial disc and vertebra system could restore vertebral height and preserve the dynamic function of the surgical area and could theoretically reduce the risk of adjacent segment degeneration compared with the anterior fusion procedure. However, our results should be considered with caution because of the low power of the study. The use of a larger sample should be considered in future studies.

Are the standard parameters of cervical spine alignment and range of motion related to age, sex, and cervical disc degeneration?

OBJECT

The aims of this study were 1) to establish the standard parameters of alignment and total and segmental range of motion (ROM) of the cervical spine in the asymptomatic population, and 2) to identify factors that influence cervical ROM and alignment.

METHODS

The authors measured 636 standard cervical lateral, flexion, and extension plain radiographs of 212 asymptomatic volunteers. The relationship between cervical alignment and total ROM was assessed with simple linear regression. Multivariate linear regression was used to determine the effect of the influential factors on cervical alignment and total and segmental ROM.

RESULTS

The mean value for C2-7 cervical alignment was 21.40° ± 12.15°, and the mean value for total ROM was 63.59° ± 15.37°. Sex was a significant factor in cervical alignment, total ROM, and segmental ROM for C2-3 and C5-6 (p < 0.05). Age had a significant negative association with both the total ROM and all of the segmental ROM measurements (p < 0.05). Cervical disc degeneration at the level of interest had a significant negative association with C4-5, C5-6, and C6-7 ROM (p < 0.05).

CONCLUSIONS

Cervical alignment in female subjects was 2.47° lower than that in male subjects. Total ROM was 3.86° greater in female than in male subjects and decreased 6.46° for each decade of aging. Segmental ROM decreased 1.28° for each decade of aging and 2.26° for each category increase in disc degeneration at the level of interest.

Mid- to long-term outcomes after cervical disc arthroplasty compared with anterior discectomy and fusion: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

To evaluate the mid- to long-term clinical outcomes after cervical disc arthroplasty (CDA) as compared with anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic cervical disc disease.

METHODS

A systematic review and a meta-analysis were performed for articles published up to March 2013. Randomized controlled trials that reported mid- to long-term outcomes (≥48 months) after CDA as compared with ACDF were included. Two authors independently extracted the articles and the predefined data.

RESULTS

Five US Food and Drug Administration randomized controlled trials that reported 4-6 years of follow-up data were retrieved. Patients who underwent CDA had a lower mid- to long-term rate of reoperation and had greater mid- to long-term improvements in the Neck Disability Index, neck and arm pain scores, and Short Form 36 Health Survey physical component score than did those who underwent ACDF. Segmental motion was maintained in patients who underwent CDA. The mid- to long-term rates of adjacent segment disease and neurological success were not significantly different between the two groups.

CONCLUSIONS

CDA may result in better mid- to long-term functional recovery and a lower rate of subsequent surgical procedures than ACDF would. A review of the literature showed that only an insufficient number of studies had investigated adjacent segment disease; therefore, it is mandatory that adequate future research should focus in this direction.