Cervical Degenerative Disc Disease Research Articles

Biotechnologies in the Treatment of Degenerative Disc Disease of the Cervical Spine

ABSTRACTDegenerative disc disease of the cervical spine is a common medical condition in the population with underlying aging, genetic, mechanical and environmental factors. It is characterized with structural collapse, osteophyte formation and loss of the loading function of the intervertebral disc. As a consequence a compression of neural structures is observed with axial neck pain, cervical radiculopathy and myelopathy.Currently, the cervical interbody fusion and artificial disc implantation are the available operative treatment options when medications and physiotherapy are ineffective. New strategies focusing on biologic modalities would be appealing. We review the advanced biotechnologies in the treatment of degenerative disc disease of the spine.Many studies are focused on therapeutic molecules capable to influence the biochemical and structural processes of intervertebral disc degeneration. These factors are categorized as anticatabolics, mitogens, chondrogenic morphogens and intracellular regulators. Another step that further opposes the simple injection of tissues with therapeutic molecules is gene therapy seeking to transfer genetic material into target cells, which in turn become in situ factories for the long-term production of desired proteins. The use of tissue-engineered intervertebral disc constructs may prove helpful when treating degenerative cervical disc disease. An in vitro technology designed to produce cartilage or bone with desired biomechanical properties to repair damaged tissues is available nowadays. In the near future the golden standard might be the replacement of the degenerated disc with biological rather than polymer or metal prostheses.However, the cost-effectiveness of the reviewed approaches has not been definitively established. Regardless of its efficacy, the safety and economic issues may ultimately determine whether these therapies are viewed as an acceptable alternative to the recent treatment options.

Cage subsidence does not, but cervical lordosis improvement does affect the long-term results of anterior cervical fusion with stand-alone cage for degenerative cervical disc disease: a retrospective study

Clinical outcomes of the stand-alone cage have been encouraging when used in anterior cervical discectomy and fusion (ACDF), but concerns remain regarding its complications, especially cage subsidence. This retrospective study was undertaken to investigate the long-term radiological and clinical outcomes of the stand-alone titanium cage and to evaluate the incidence of cage subsidence in relation to the clinical outcome in the surgical treatment of degenerative cervical disc disease. A total of 57 consecutive patients (68 levels) who underwent ACDF using a titanium box cage for the treatment of cervical radiculopathy and/or myelopathy were reviewed for the radiological and clinical outcomes. They were followed for at least 5 years. Radiographs were obtained before and after surgery, 3 months postoperatively, and at the final follow-up to determine the presence of fusion and cage subsidence. The Cobb angle of C2-C7 and the vertebral bodies adjacent to the treated disc were measured to evaluate the cervical sagittal alignment and local lordosis. The disc height was measured as well. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score for cervical myelopathy, before and after surgery, and at the final follow-up. The recovery rate of JOA score was also calculated. The Visual Analogue Scale (VAS) score of neck and radicular pain were evaluated as well. The fusion rate was 95.6% (65/68) 3 months after surgery. Successful bone fusion was achieved in all patients at the final follow-up. Cage subsidence occurred in 13 cages (19.1%) at 3-month follow-up; however, there was no relation between fusion and cage subsidence. Cervical and local lordosis improved after surgery, with the improvement preserved at the final follow-up. The preoperative disc height of both subsidence and non-subsidence patients was similar; however, postoperative posterior disc height (PDH) of subsidence group was significantly greater than of non-subsidence group. Significant improvement of the JOA score was noted immediately after surgery and at the final follow-up. There was no significant difference of the recovery rate of JOA score between subsidence and non-subsidence groups. The recovery rate of JOA score was significantly related to the improvement of the C2-C7 Cobb angle. The VAS score regarding neck and radicular pain was significantly improved after surgery and at the final follow-up. There was no significant difference of the neck and radicular pain between both subsidence and non-subsidence groups. The results suggest that the clinical and radiological outcomes of the stand-alone titanium box cage for the surgical treatment of one- or two-level degenerative cervical disc disease are satisfactory. Cage subsidence does not exert significant impact upon the long-term clinical outcome although it is common for the stand-alone cages. The cervical lordosis may be more important for the long-term clinical outcome than cage subsidence.

Artificial Cervical Disc Arthroplasty

Systematic Review. (1) To qualitatively analyze the literature on the efficacy and effectiveness of artificial cervical disc arthroplasty (ACDA). (2) To highlight methodological and reporting issues of randomized controlled trials (RCT) reports on effectiveness of ACDA compared to cervical fusion. ACDA is an alternate surgical procedure that may replace cervical fusion in selected patients suffering from cervical degenerative disc disease. We searched seven electronic databases, including MEDLINE, Cochrane Library, and EMBASE, unpublished sources, and reference lists for studies on the efficacy and effectiveness of ACDA compared to cervical fusion--the surgical standard of care for patients with cervical degenerative disc disease. A total of 622 studies were retrieved, of which 18 (13 case series, four RCT reports, one nonrandomized comparative study) met the inclusion criteria for this review. The four RCTs and the nonrandomized comparative study concluded that the effectiveness of ACDA is not inferior to that of cervical fusion in the short term (up to 2-yr follow-up). The safety profile of both procedures appears similar. The case series reviewed noted improved clinical outcomes at 1 or 2 years after one or multiple-level ACDA. ACDA is a surgical procedure that may replace cervical fusion in selected patients suffering from cervical degenerative disc disease. Within 2 years of follow-up, the effectiveness of ACDA appears similar to that of cervical fusion. Weak evidence exists that ACDA may be superior to fusion for treating neck and arm pain. Future studies should report change scores and change score variance in accordance with RCT guidelines, in order to strengthen credibility of conclusions and to facilitate meta-analyses of studies.

Predicting Health-Utility Scores From the Cervical Spine Outcomes Questionnaire in a Multicenter Nationwide Study of Anterior Cervical Spine Surgery

Cross-sectional analysis of the Cervical Spine Research Society Outcomes Study, a longitudinal multicenter cohort study. To provide a statistical model for estimating health utility from the Cervical Spine Outcomes Questionnaire (CSOQ) domain scores. There is consensus among health-policy researchers that the results of economic evaluations of health can be reported in quality-adjusted life-years (QALY). The CSOQ is a condition-specific instrument that assesses individuals across several domains, including neck and arm/shoulder pain and psychological distress. The CSOQ and 36-Item Short Form Health Survey (SF-36) were prospectively administered before surgery (within 4 weeks) and after surgery (at 3, 6, and 24 months) to individuals undergoing anterior cervical decompression and fusion for degenerative disc disease of the cervical spine. Using methods reported by Brazier et al, health utility (SF-6D) was estimated using the SF-36. Regression analyses were used on a training dataset (n = 164) to compute the SF-6D from the domain scores of the CSOQ. A validation dataset (n = 328) was used to estimate the SF-6D for comparison to the calculated health utility from the SF-36. RESULTS.: Domain scores were moderately correlated with health utility (SF-6D) (P < 0.001) with correlation coefficients ranging from 0.48 to 0.70. The regression equation to predict SF-6D on the basis of CSOQ domain scores and patient age using the training dataset accounted for 65% of the variation in health utility. In the validation dataset, predicted SF-6D was positively correlated with observed SF-6D (r = 0.680, P < 0.001). Our findings show that the CSOQ's domain scores can be used to estimate health-utility scores among those undergoing elective anterior cervical decompression and fusion for cervical degenerative disc disease. The ability to assess health utility, coupled with the psychometric properties of the CSOQ, should increase the clinical utility of this patient-reported outcomes instrument.

Comparison of the Mobi C ® Cervical Artificial Disc to Anterior Cervical Discectomy and Fusion in the Treatment of Symptomatic Cervical Degenerative Disc Disease at Two Levels

The current standard of care in the treatment of radiculopathy or myeloradiculopathy associated with cervical degenerative disc disease (DDD) is anterior cervical discectomy and fusion (ACDF). ACDF is the current standard of care for treatment of symptomatic DDD at both one level and multiple levels of cervical spine. Recently, through the results of strictly controlled clinical studies, total disc replacement (TDR) has been shown to be non-inferior and in some cases superior to ACDF in relieving neurological symptoms associated with DDD at one vertebral segment level.

National Utilization Trends of Cervical Artificial Disc Replacement Compared to Anterior Cervical Fusion

Complications of Anterior Cervical Discectomy and Fusion (ACDF) have prompted introduction of cervical disc arthroplasty (CDA) in the treatment of myelopathy or radiculopathy caused by degenerative cervical disc disease at one level. CDA is designed to preserve motion, and avoid adjacent segment degeneration.

Multicenter, Prospective, Randomized, Controlled Investigational Device Exemption Study Comparing Mobi-C® Cervical Artificial Disc to Anterior Fusion in the Treatment of Symptomatic Cervical Degenerative Disc Disease

Anterior cervical fusion (ACF) has been long accepted as the standard of care for radiculopathy or myeloradiculopathy associated with degenerated cervical discs. Cervical total disc replacement (TDR) is designed to provide motion and relieve pain. The most viable way to evaluate the effectiveness of TDR in reducing symptoms is to compare it to ACF.

Analysis of the Several Factors that may affect the Radiological and Clinical Outcome in Cervical Arthroplasty

Spinal arthroplasty is becoming more widely performed in the treatment of degenerative cervical disc disease. Although there have been many studies to prove it’s efficacy and benefits over arthrodesis, some conditions which lead to undesirable consequences at the follow up(F/U) have been also reported. Surgeons planning to undertake cervical arthroplasty should be aware of the these factors and variables which can affect the outcome in order to get the consistent favorable result.

Results of Cervical Arthroplasty Compared with Anterior Discectomy and Fusion: Four-Year Clinical Outcomes in a Prospective, Randomized Controlled Trial

The published two-year results of the pivotal U.S. Food and Drug Administration investigational device exemption trial with the use of the Bryan cervical disc arthroplasty compared with anterior cervical discectomy with fusion for treating single-level degenerative cervical disc disease revealed a significantly superior overall success rate in the arthroplasty group. The purpose of this study was to evaluate the midterm safety and effectiveness of the Bryan disc as an alternative to arthrodesis following anterior cervical discectomy. A prospective, multicenter randomized clinical trial was undertaken for the treatment of persistent radiculopathy or myelopathy due to single-level cervical disc herniations or spondylosis. Patients were randomized to treatment with either the Bryan disc (the arthroplasty group; 242 patients) or anterior cervical discectomy and fusion (the fusion group; 221 patients). Patients completed preoperative and postoperative self-assessment forms at specified intervals and had radiographs made preoperatively, at six weeks, and at three, six, twelve, twenty-four, and forty-eight months after surgery. The primary outcome measure was overall success, a composite variable of safety and efficacy measures. Numerous secondary measures were assessed. The follow-up data for up to twenty-four months have been previously published. We report in the present study the forty-eight-month data collected on 181 patients who received the Bryan disc and 138 patients who underwent anterior cervical discectomy and fusion. The study groups were demographically similar. Substantial reduction in Neck Disability Index scores occurred in both groups compared with preoperative values. The greater improvement in the Neck Disability Index score in the Bryan disc cohort persisted through the four-year follow-up period (p < 0.001). The four-year overall success rates were 85.1% and 72.5% for the arthroplasty and fusion groups, respectively (p = 0.004). The improvement in the arm pain score was substantial for both groups and significantly greater in the Bryan disc cohort (p = 0.028), and the neck pain scores showed persistently greater improvement in the Bryan disc group at forty-eight months of follow-up (p = 0.001). Short Form-36 physical component score improvement remained greater among the Bryan disc cohort (p = 0.007). The mean range of motion for the Bryan disc was 8.08° and 8.48° at twenty-four and forty-eight months, respectively. Total and serious adverse event rates were similar between the groups. The forty-eight-month follow-up data in the present report showed consistent, sustained significantly superior outcomes for cervical spine arthroplasty compared with cervical spine fusion. The arthroplasty cohort continued to show significantly greater improvements in Neck Disability Index, neck pain score, arm pain score, and Short Form-36 physical component score, as well as the primary outcome measure, overall success, at forty-eight months following surgery.

Anterior discectomies and interbody cage fusion without plate fixation for 5-level cervical degenerative disc disease: A 5-year follow-up

Anterior discectomy and interbody fusion have been proven to be a safe and effective procedure for the treatment of cervical degenerative disc disease. Clinical results for 1- to 4-level interbody cage fusion without plate fixation are encouraging. Five-level cervical interbody cage fusion without plate fixation has not yet been previously reported. We report a 63-year-old female patient suffering from severe pain of the bilateral shoulders and left upper extremity with numbness and weakness of legs. Magnetic resonance imaging showed cervical degenerative disc herniation with cord compression between the levels of C2 and C7. Anterior cervical discectomy and interbody cage fusion without plate fixation were performed. Pain and neurological function improved dramatically after surgery. Asymptomatic subsidence of the cage occurred at the level of C6-7 two months postoperatively with no further progression of subsidence 5 years postoperatively. Good stability of the cages was seen on flexion and extension radiographs 5 years postoperatively. We report the first case with good long-term results of 5-level interbody cage fusion without plate fixation for anterior cervical degenerative disc surgery.

Adjacent-level degeneration after cervical disc arthroplasty versus fusion

The principal objective of this study was to evaluate the incidence of adjacent-segment degeneration (ASD) in patients who underwent cervical disc arthroplasty (CDA) as compared with anterior cervical discectomy and fusion (ACDF). It is a prospective cohort study of patients with a single-level cervical degenerative disc disease from C3 to C7 who underwent CDA or ACDF between January 2004 and December 2006, with a minimum follow-up of 3 years. The patients were evaluated pre- and postoperatively with the visual analog scale (VAS), the neck disability index (NDI), and a complete neurological examination. Plain radiographic assessments included sagittal-plane angulation, range of motion (ROM), and radiological signs of ASD. One hundred and five patients underwent ACDF and 85 were treated with CDA. The postoperative VAS and NDI were equivalent in both groups. The ROM was preserved in the CDA group but with a small decreased tendency within the time. Radiographic evidence of ASD was found in 11 (10.5%) patients in the ACDF group and in 7 (8.8%) subjects in the CDA group. The Kaplan-Meier survival analysis for the ASD occurrence did not reach statistically significant differences (log rank, P = 0.72). Preservation of motion in the CDA patients was not associated with a reduction of the incidence of symptomatic adjacent-segment disease and there may be other factors that influence ASD.

Minimum Clinically Important Differences in the Cervical Spine Outcomes Questionnaire

The minimum clinically important difference is a clinically relevant threshold of improvement. A substantial clinical benefit is a threshold of change that correlates with clinically important improvement. The Cervical Spine Outcomes Questionnaire is a disease-specific, patient-reported outcomes instrument that was developed to be sensitive to changes associated with surgical treatment for degenerative cervical disc disease. To determine thresholds for change in these domain scores that are important from the patient's perspective, we estimated the minimum clinically important difference and substantial clinical benefit values for this questionnaire's domain scores. We evaluated 252 patients from the Cervical Spine Research Society Outcomes Study at their six-month follow-up visits after anterior cervical spine decompression and arthrodesis. Using a receiver operating characteristics curve, with the health transition item of the Short Form-36 as an anchor, we determined that the minimum clinically important difference (the value that maximized sensitivity and specificity to differentiate the "somewhat better" and "much better" responses from others) and the substantial clinical benefit (the value that maximized sensitivity and specificity to differentiate the "much better" response from others) for our questionnaire's domain scores. Responses were scaled between 0 and 1 point; higher scores denoted more severe impairment. Patient and clinical characteristics were tested to determine their influence on score changes. The minimum clinically important difference ranged from 0.13 point (for functional disability) to 0.24 point (for arm/shoulder pain). The substantial clinical benefit score ranged from 0.20 point (for functional disability or physical symptoms other than pain) to 0.30 point (for neck or arm/shoulder pain). Age, sex, and duration of current symptoms were not associated with change in our questionnaire's domain scores. A 0.13-point change in the functional disability domain score indicated a clinically important difference in a self-reported outcome after anterior cervical spine surgery. A 0.30-point change in neck pain after surgery indicated a clinically important clinical benefit. This information, coupled with previous reports of the psychometric stability of the Cervical Spine Outcomes Questionnaire, should increase the clinical utility of this patient-reported outcomes instrument.

Adjacent Segment Motion After Anterior Cervical Discectomy and Fusion Versus ProDisc-C Cervical Total Disk Arthroplasty

Post hoc analysis of data acquired in a prospective, randomized, controlled trial. To compare adjacent segment motion after anterior cervical discectomy and fusion (ACDF) versus cervical total disc arthroplasty (TDA). TDA has been designed to be a motion-preserving device, thus theoretically normalizing adjacent segment kinematics. Clinical studies with short-term follow-up have yet to demonstrate a consistent significant difference in the incidence of adjacent segment disease. Two hundred nine patients at 13 sites were treated in a prospective, randomized, controlled trial of ACDF versus TDA for single-level symptomatic cervical degenerative disc disease (SCDD). Flexion and extension radiographs were obtained at all follow-up visits. Changes in ROM were compared using the Wilcoxon signed-rank test and the Mann-Whitney U test. Predictors of postoperative ROM were determined by multivariate analysis using mixed effects linear regression. Data for 199 patients were available with 24-month follow-up. The groups were similar with respect to baseline demographics. A significant increase in motion at the cranial and caudal adjacent segments after surgery was observed in the ACDF group only (cranial: ACDF: +1.4° (0.4, 2.4), P = 0.01; TDA: +0.8°, (-0.1, +1.7), P = 0.166; caudal: ACDF: +2.6° (1.3, 3.9), P < 0.0001; TDA: +1.3, (-0.2, +2.8), P = 0.359). No significant difference in adjacent segment ROM was observed between ACDF and TDA. Only time was a significant predictor of postoperative ROM at both the cranial and caudal adjacent segments. Adjacent segment kinematics may be altered after ACDF and TDA. Multivariate analysis showed time to be a significant predictor of changes in adjacent segment ROM. No association between the treatment chosen (ACDF vs. TDA) and ROM was observed. Furthermore clinical follow-up is needed to determine whether possible differences in adjacent segment motion affect the prevalence of adjacent segment disease in the two groups.

Polymethylmethacrylate-assisted ventral discectomy: Rate of pseudarthrosis and clinical outcome with a minimum follow-up of 5 years

BackgroundPolymethylmethacrylate (PMMA) assisted ventral discectomy has been criticized for high rates of graft migration and pseudarthrosis when compared with various other fusion procedures for the treatment of cervical degenerative disc disease (DDD), therefore rendering it not the preferred choice of treatment today. Recently however spine surgery has been developing towards preservation rather than restriction of motion, indicating that fusion might not be necessary for clinical success. This study presents a long term comparison of clinical and radiological data from patients with pseudarthrosis and solid arthrodesis after PMMA assisted ventral discectomy was performed.MethodsFrom 1986 to 2004 416 patients underwent ventral discectomy and PMMA interposition for DDD. The clinical and radiological outcome was assessed for 50 of 127 eligible patients after a mean of 8.1 years. Based on postoperative radiographs the patients were dichotomized in those with a pseudarthrosis (group A) and those with solid arthrodesis (group B).ResultsPseudarthrosis with movement of more than 2 of the operated segment was noted in 17 cases (group A). In 33 cases no movement of the vertebral segment could be detected (group B). The analysis of the clinical data assessed through the neck disability index (NDI), the visual analogue scale (VAS) of neck and arm pain and Odom's criteria did not show any significant differences between the groups.Patients from group B showed a trend to higher adjacent segment degeneration (ASD) than group A (p = 0.06). This correlated with the age of the patients.ConclusionsPMMA assisted discectomy shows a high rate of pseudarthrosis. But the clinical long-term success does not seem to be negatively affected by this.

Systematic Review of Anterior Interbody Fusion Techniques for Single- and Double-Level Cervical Degenerative Disc Disease

A systematic review of randomized controlled trials. To determine which technique of anterior cervical interbody fusion (ACIF) gives the best outcome in patients with cervical degenerative disc disease. The number of surgical techniques for decompression and ACIF as treatment for cervical degenerative disc disease has increased rapidly, but the rationale for the choice between different techniques remains unclear. From a comprehensive search, we selected randomized studies that compared anterior cervical decompression and ACIF techniques, in patients with chronic single- or double-level degenerative disc disease or disc herniation. Risk of bias was assessed using the criteria of the Cochrane back review group. Thirty-three studies with 2267 patients were included. The major treatments were discectomy alone and addition of an ACIF procedure (graft, cement, cage, and plates). At best, there was very low-quality evidence of little or no difference in pain relief between the techniques. We found moderate quality evidence for few secondary outcomes. Odom's criteria were not different between iliac crest autograft and a metal cage (risk ratio [RR]: 1.11; 95% confidence interval [CI]: 0.99-1.24). Bone graft produced more fusion than discectomy (RR: 0.22; 95% CI: 0.17-0.48). Complication rates were not different between discectomy and iliac crest autograft (RR: 1.56; 95% CI: 0.71-3.43). Low-quality evidence was found that iliac crest autograft results in better fusion than a cage (RR: 1.87; 95% CI: 1.10-3.17); but more complications (RR: 0.33; 95% CI: 0.12-0.92). When fusion of the motion segment is considered to be the working mechanism for pain relief and functional improvement, iliac crest autograft appears to be the golden standard. When ignoring fusion rates and looking at complication rates, a cage as a golden standard has a weak evidence base over iliac crest autograft, but not over discectomy.

Study of the Role of Nova Bone as a Filling Material in Cervical Cage in Anterior Fusion of Cervical Spine in Patients with Degenerative Cervical Disc Disease

Objectives: There are several reports about the therapeutic effects of cervical interbody cages for cervicaldegenerative disorders. Few have addressed the role of the filling material in fusion and improving the clinicalsymptoms. This study tries to study the effects of Novabone as a filling material in Solis cages in patients withcervical disc protrusions. The results have been compared with the results from studies that used autografts to fillthe cage.Material & Methods: This study includes patients treated surgically from 2003 to 2007 for cervical discopathywith anterior fusion technique. We used Solis cage filled with Novabone mixed with autologous bone fragments.The results for fusion and improvement in axial and radicular pain have been determined and compared with theresults of other studies. Also the complications and radiologic findings have been reviewed.Results: 33 patients were operated on from 2003-2007, anteriorly using Solis cages filled with Novabone. 19were men (57.6%) and 14 women (42.4%). The average age was 47.1 y. 23 patients (69.7%) have been operatedon one level and 10 patients (30.3%) were operated on more than one level. 44 cages were inserted. Mean followup period was 14.3 months. After one year the fusion rate was 91.3% at one level and 80% in patients with morethan one level and 87.8% overall.Conclusion: According to our study, the fusion rate with Novabone and autologous bone filled cages were lowerthan that achieved in series using autologous bone but it reached the same rate later. It is highly recommendedthat the cervical cages be filled with autologous bone or Novabone mixed with patints bone chips.

Study of the Role of Nova Bone as a Filling Material in Cervical Cage in Anterior Fusion of Cervical Spine in Patients with Degenerative Cervical Disc Disease

Objectives: There are several reports about the therapeutic effects of cervical interbody cages for cervicaldegenerative disorders. Few have addressed the role of the filling material in fusion and improving the clinicalsymptoms. This study tries to study the effects of Novabone as a filling material in Solis cages in patients withcervical disc protrusions. The results have been compared with the results from studies that used autografts to fillthe cage.Material & Methods: This study includes patients treated surgically from 2003 to 2007 for cervical discopathywith anterior fusion technique. We used Solis cage filled with Novabone mixed with autologous bone fragments.The results for fusion and improvement in axial and radicular pain have been determined and compared with theresults of other studies. Also the complications and radiologic findings have been reviewed.Results: 33 patients were operated on from 2003-2007, anteriorly using Solis cages filled with Novabone. 19were men (57.6%) and 14 women (42.4%). The average age was 47.1 y. 23 patients (69.7%) have been operatedon one level and 10 patients (30.3%) were operated on more than one level. 44 cages were inserted. Mean followup period was 14.3 months. After one year the fusion rate was 91.3% at one level and 80% in patients with morethan one level and 87.8% overall.Conclusion: According to our study, the fusion rate with Novabone and autologous bone filled cages were lowerthan that achieved in series using autologous bone but it reached the same rate later. It is highly recommendedthat the cervical cages be filled with autologous bone or Novabone mixed with patints bone chips.

Early follow-up outcomes after treatment of degenerative disc disease with the discover cervical disc prosthesis

Background contextAlthough anterior cervical decompression and fusion has been used successfully in the treatment of symptomatic radiculopathy and/or myelopathy, biomechanical studies have suggested possible deleterious effects of cervical fusion on adjacent level kinematics. The emergence of cervical arthroplasty as an alternative to arthrodesis may restore a more normal spinal movement and reduces a kinematic strain on adjacent segments. To date, with existing prostheses, the risk adjacent segment disease has not been proven to be reduced using artificial disc replacement. PurposeThe study was designed to investigate the surgical techniques and clinical effects of the Discover artificial cervical disc prosthesis in a Chinese population and observe the stability and range of movement in the early and immediate postoperative period. Study design/settingOur clinical study design was prospective, concurrently enrolled, and single-center trial of the artificial cervical disc prosthesis (DePuy Spine, Raynham, MA, USA) in the treatment of patients with single- and two-level degenerative disc disease of the cervical spine. Patient sampleProcedure was performed in 25 patients. Outcome measuresThe functional spinal unit (FSU) and global angles, segmental and overall range of motion, FSU heights, and clinical parameters checked with Neck Disability Index (NDI), Japanese Orthopedic Association (JOA), Odom's scale, and visual analog scale (VAS) pain score were assessed. MethodsTwenty-five patients (26 discs) consecutively underwent cervical arthroplasty using the Discover artificial cervical disc in our hospital. Clinical and radiologic follow-up was performed. The radiographic parameters evaluated included the treated segments and the overall curvature of the cervical spine. ResultsAll the patients were assessed between 12 months and 18 months after surgery (average 15.3 months). According to Odom's scale, all 25 patients (26 levels) had good to excellent outcomes by independent assessment. Mean NDI, JOA, and VAS scores showed statistical improvements in the early and immediate postoperative period. The range of movement recovered to the preoperative value during the follow-up. The treated segment ultimately showed preservation of movement when compared with preoperative levels. No prosthesis subsidence or excursion was identified, and no heterotopic ossification was found in the replaced levels. ConclusionThese early results from a small cohort demonstrate that cervical arthroplasty with the Discover artificial cervical disc for the treatment of degenerative cervical disc disease may provide a good clinical outcome and preserves some motion postoperatively. Although early outcomes are promising, this is also a relatively new technology and prosthesis, long-term follow-up studies with larger patient numbers are required to assess safety and efficacy compared with alternative treatments.

Horner Syndrome Following a Selective Cervical Nerve Root Block

A 31-year-old man with cervical degenerative disc disease was seen at an outside institution for a right selective nerve root block at C7. Following the procedure, he had right ptosis and miosis. Pharmacologic testing confirmed a right Horner syndrome. MRI and MRA showed no arterial dissection. This report documents the unusual occurrence of permanent Horner syndrome following a selective cervical nerve root block.

Comparison between single- and multi-level patients: clinical and radiological outcomes 2 years after cervical disc replacement

In cervical multi-level degenerative pathology, considering the morbidity of the extensive fusion techniques, some authors advocate for the multilevel disc replacement. This study compared the safety and efficacy of disc replacement with an unconstrained prosthesis in multi- versus single-level patients. A total of 231 patients with cervical degenerative disc disease (DDD) who were treated with cervical disc replacement and completed their 24 months follow-up were analyzed prospectively: 175 were treated at one level, 56 at 2 levels or more. Comparison between both groups was based on usual clinical and radiological outcomes [Neck Disability Index (NDI), Visual Analog Scale (VAS), Range of Motion, satisfaction]. Safety assessments, including complication and subsequent surgeries, were also documented and compared. Mean NDI and VAS scores for neck and arm pain were improved in both groups similarly. Improvement of mobility at treated segments was also similar. Nevertheless, in the multi-level group, analgesic use was significantly higher and occurrence of Heterotopic Ossification significantly lower than in the single-level group. Subject satisfaction was nearly equal, as 94.2% of single-level group patients would undergo the surgery again versus 94.5% in the multi-level group. The overall success rate did not differ significantly. Multi-level DDD is a challenging indication in the cervical spine. This study showed no major significant clinical difference between the two groups. We need further studies to know more about the impact of multi-level arthroplasty, especially on the adjacent segments, but these results demonstrate initial safety and effectiveness in this patient sample.