Cervical Disc Replacement Surgery Research Articles

Paper on role of cervical disc replacement surgery in cervical pivd patients in both elderly and young population and it’s comparison with anterior cervical dissectomy and fusion

For more than fifty years, anterior cervical discectomy and fusion (ACDF) has been a widely accepted operation for cervical spine degenerative diseases, including disc herniation and spondylosis, that are refractory to medical management. The high rates of success and patients’ satisfaction with ACDF has made the operation a standard of care in common neurosurgical practice, however, the advantages of cervical disc arthroplasty (CDA) over fusion including maintaining normal neck motion and reducing degeneration of adjacent segments of the cervical spineTo study the role of cervical disc replacement surgery in cervical pivd patients in both elderly and young population and it’s comparison with anterior cervical dissectomy and fusion with age variability taken into consideration. The inclusion and exclusion criteria used, The operative procedure for both ACDF and CDA, The further follow up studies considering clinical as well as radiological outcome The most commonly indexed levels of CDA were C4–5 and C5–6, accounting for 85%of the entire series.The clinical outcomes, including VAS of neck and arm pain, NDI, and JOA scores were all similarly satisfactory after the surgery, during the follow-up. CDAs has been demonstrated to preserve segmental motion at long-term followup and to decrease the incidence of adjacent-level surgery, as compared to ACDF. Cervical global alignment and the segmental angle at rest improves after cervical arthroplasty

Sagittal sequence and clinical efficacy of cervical disc replacement and hybrid surgery in the treatment of cervical spondylotic myelopathy: a retrospective study.

Hybrid surgery (HS) combines anterior cervical discectomy and fusion (ACDF) with cervical disc replacement (CDR) is gradually being more frequently implemented, but there are few studies reporting the safety and effectiveness of hybrid surgery in three levels cervical spondylotic myelopathy. The clinical and radiographic data of patients with three-segment cervical spondylosis, who underwent CDR, ACDF and HS in our hospital from February 2007 to February 2013 were analyzed. The Visual Analog Scale (VAS), Japanese Orthopedic Association (JOA) and Neck Disability Index (NDI) were used to evaluate the clinical efficacy post surgery. Cervical spine x-rays were conducted to assess ROM, CL, T1S and relevant outcomes. A total of 94 patients were included in the study: 26 in the CDR group, 13 in the HS1 group, 31 in the HS2 group, and 24 in the ACDF group. Most patients in the CDR group were younger. There was no difference in the follow-up duration, blood loss volume or surgery time (P > 0.05). Four groups reported improvements in JOA and NDI scores compared to baseline. There was no significant difference in the final JOA, final NDI or recovery rate among the 4 groups. The final ROM was smaller in the ACDF group than in the other 3 groups. There was no difference among the four groups in the final UROM, final LROM or their changes. There was no difference in the final T1S, final SVA or their change among the four groups. All groups showed similar changes in CL and T1S-CL. There was no difference in the clinical outcomes of ACDF, CDR, or hybrid surgery. CDR can better preserve the mobility of the cervical spine. Neither CDR nor hybrid surgery was significantly advantageous over ACDF in restoring the sagittal sequence in patients with three-level CSM.

Comparison of the effects of different artificial discs on hybrid surgery: A finite element analysis.

In recent years, artificial cervical discs have been used in intervertebral disc replacement surgery and hybrid surgery (HS). The advantages and disadvantages of different artificial cervical discs in artificial cervical disc replacement surgery have been compared. However, few scholars have studied the biomechanical effects of various artificial disc prostheses on the human cervical spine in HS which include the Anterior Cervical Discectomy and Fusion (ACDF) and Cervical Disc Arthroplasty (CDA). This study compared the biomechanical behavior of Mobi-C and Prestige LP in the operative and adjacent segments during two-level hybrid surgery. A three-dimensional finite element model of C2-C7 was first established and validated. Subsequently, clinical surgery was then simulated to establish a surgical model of anterior cervical fusion at the C4-C5 level. Mobi-C and Prestige-LP artificial disc prostheses were implanted at the C5-C6 level to create two hybrid models. All finite element models were fixed on the lower endplate of the C7 vertebra and subjected to a load of 73.6 N and different directions of 1 Nm torque on the odontoid process of the C2 vertebra to simulate human flexion, extension, lateral bending, and axial rotation. This paper compares the ROM, intervertebral pressure, and facet joint force after hybrid surgery with the intact model. The results show that compared with Prestige LP, Mobi-C can improve ROM of the replacement segment and compensate for the intervertebral pressure of the adjacent segment more effectively, but the facet joint pressure of the replacement segment may be higher.

18. The impact of race/ethnicity on length of stay, discharge destination and cost of care after anterior cervical decompression and fusion

18. The impact of race/ethnicity on length of stay, discharge destination and cost of care after anterior cervical decompression and fusion

Manual therapy interventions in the management of adults with prior cervical spine surgery for degenerative conditions: a scoping review

ObjectiveCervical spine surgeries for degenerative conditions are rapidly increasing. Cervical post-surgery syndrome consisting of chronic pain, adjacent segment disease, recurrent disc herniation, facet joint pain, and/or epidural scarring is common. Repeat surgery is regularly recommended, though patients are often unable to undergo or decline further surgery. Manual therapy is included in clinical practice guidelines for neck pain and related disorders, however clinical guidance for utilization of manual therapy in adults with prior cervical spine surgery is lacking. This study aimed to synthesize available literature and characterize outcomes and adverse events for manual therapy interventions in adults with prior cervical spine surgery due to degenerative conditions.MethodsPreferred reporting items for systematic reviews and meta-analyses extension for scoping reviews was followed. PubMed, Cumulative Index of Nursing and Allied Health Literature, physiotherapy evidence database, and Index to Chiropractic Literature were searched from inception through October 2021. English-language literature comprised of randomized clinical trials (RCT), case–control, cohort, and case report designs were included. Adults undergoing manual therapy, with or without combination of other interventions, with prior cervical spine surgery due to degenerative conditions were included.ResultsTwelve articles were identified, including 10 case reports, 1 low-quality RCT, and 1 acceptable-quality RCT. Eight case reports described 9 patients with history of fusion surgery. Two case reports described 2 patients with history of discectomy. One case report described one patient with separate operations of a discectomy at one level and a fusion at another level. One case report described 2 patients with history of cervical disc replacement surgery. The two RCTs included 63 and 86 participants, respectively. Use of manual joint mobilization/manipulation, table/instrument assisted mobilization/manipulation, and multimodal interventions were described in eligible studies. Favorable clinical outcomes were reported in 10 studies. Six case reports/series involving 8 patients described use of unclassified forms of manual therapy. Eight studies described the use of multimodal interventions along with manual therapy. One study described high patient satisfaction. Two studies, accounting for 3 patients, reported serious adverse events.ConclusionsThere is a lack of literature informing evidence related to clinical outcomes, patient satisfaction, and adverse events associated with manual therapy for patients with prior cervical spine surgery due to degenerative conditions. High-quality studies of higher-level hierarchical study design are needed to understand the clinical utility and safety profile of manual therapy for this population.

71. Long-term follow-up of a consecutive series with prodisc C Nova at a single institution

<h3>BACKGROUND CONTEXT</h3> Cervical total disc replacement surgery has more than two decades of experience. Device designs that feature a ball and socket mechanism with central keels, such as the original prodisc C, have been shown to perform favorably. However, a tall central keel can potentially be less than optimal for patients with shorter vertebral bodies or in multi-level cases. A variation of the prodisc C design was subsequently created, keeping the original mechanism of action but changing to shorter, tri-keel fixation. prodisc C Nova (Centinel Spine, West Chester, PA), which has one central keel cranially and two lateral keels caudally, was developed and released in Europe in 2010. <h3>PURPOSE</h3> The primary objective of this study was to evaluate the long-term clinical and radiographic outcomes. <h3>STUDY DESIGN/SETTING</h3> Prospective, consecutive series. <h3>PATIENT SAMPLE</h3> Fifty-six patients (37 Female, 19 Male) underwent total disc replacement surgery for symptomatic cervical disc disease at a single level. <h3>OUTCOME MEASURES</h3> Evaluation at each visit included patient self-assessments, eg, visual analog scale (VAS) pain and satisfaction, walking, physical and neurological examination, and radiographic evaluation. Radiographic evaluation was performed by an independent radiologic group (Medical Metrics, Houston, Texas). <h3>METHODS</h3> After failing conservative therapy, patients were evaluated for their suitability for surgical intervention of their symptomatic cervical disc degeneration. Patients underwent an anterior discectomy and total disc replacement. The clinical status of each patient was evaluated pre- and postoperatively at 6 weeks, 3 months, 6 months, 1 year and annually thereafter. <h3>RESULTS</h3> Patients were followed through 9 years postoperatively. At baseline, the average age was 48.22 ± 8.98 years and an average BMI 27.68 ± 4.78 kg/m2. VAS neck and VAS arm pain both showed statistically significant reduction from baseline by 6 weeks postop and were maintained through 9 years. VAS neck was 6.67 ±2.29 mm at baseline and 3.25 ± 3.59 mm at 9 years. VAS arm was 6.02 ±2.59 mm preoperatively and 4.00 ± 3.65 mm at 9 years. Patients reported high satisfaction and willingness to have operation again at all time points. Patients walking frequency increased by month 3 and was maintained in ≥ 75% of patients at all timepoints out to 9 years. Radiographic results showed no migration or protrusions through 9 years follow-up. One case of minor subsidence was measured after 5 years but did not require surgical intervention and had satisfactory results. One patient required reoperation at 10 months for persistent pain and required facet denervation at both cranial and caudal adjacent levels as well as index level. The disc remained intact and had good follow-up. There were no device failures. <h3>CONCLUSIONS</h3> Long-term follow-up shows that prodisc C Nova has patient-reported outcomes and radiographic results comparable to that published with prodisc C. Patients reported consistent and sustained improvement through 9 years of follow-up. Not only was pain relief achieved but functional improvement through walking was sustained. There were also no adjacent level surgeries over the 9 years, showing that maintaining motion has other potential clinical benefits beyond the index level. The change in keel fixation design did not affect patient outcomes, providing another option for some patients. <h3>FDA DEVICE/DRUG STATUS</h3> prodisc C Nova (Investigational/Not approved)

Extended-Reality Technologies: An Overview of Emerging Applications in Medical Education and Clinical Care.

Extended-Reality Technologies: An Overview of Emerging Applications in Medical Education and Clinical Care.

Comparison of One-Year Outcomes with Polyetheretherketone (Peek) Cage or Disc Prosthesis in Cervical Disc Replacement Surgery

Comparison of One-Year Outcomes with Polyetheretherketone (Peek) Cage or Disc Prosthesis in Cervical Disc Replacement Surgery

Motion preservation after cervical total disc replacement surgery-fact or fiction?

Cervical disc replacement surgery aims to preserve cervical motion in younger patients who present with symptomatic degenerative cervical disc herniation and mobile facet joints. We aimed to determine the demographics, pre-operative range of motion, operative parameters, post-operative parameters, range of motion at 2-years post-operatively, in 27 patients who presented to our unit over a 6-year period who underwent cervical total disc replacement surgery. Materials and methodsWe performed a retrospective chart review of 27 patients who presented to our unit with degenerative cervical disc disease, from 01 January 2014 – 31 December 2019, who underwent cervical disc replacement surgery. The data collected included patient age; gender; mechanism of injury; clinical presentation; cervical level/s involved; description and site of the disc herniation; length of preoperative symptomatology; pre-operative cervical range of motion; length of operative procedure; volume of intra-operative blood loss; amount of immediate post-operative radiculopathy pain assessed by the visual analogue scale; complications; length of hospital stay; and cervical range of motion at 2-year follow-up. ResultsThe mean age of our subjects was 45.5 (+/-6.5) years. Regarding gender 11/27 (41%) subjects were female and 16/27 (59%) subjects were male. In terms of number of levels 21/27 (78%) subjects had single level surgery and 6/27 (22%) subjects had double level surgery. Considering age categories, patients in the 4th decade demonstrated a statistically significant increase between their pre-operative segmental range of cervical flexion and their post-operative segmental range of cervical flexion (p = 0.02). ConclusionThrough the results of our study we report that in our 27 subjects cervical total disc replacement surgery was motion preserving in 100% of our subjects at a 2-year study end point. We further report that all our subjects demonstrated some degree of increase in their segmental ranges of motion in all planes, although this was largely insignificant.

252. Kinematic response of cervical disc arthroplasty in different hybrid constructs

BACKGROUND CONTEXT The use of cervical disc arthroplasty (CDA) adjacent to an anterior cervical decompression and fusion (ACDF), a hybrid construct, is an attractive alternative to a multilevel cervical fusion operation. Consider a clinical scenario where a patient with a prior fusion at C6-C7 develops new radiculopathy and/or myelopathy at C5-C6. A surgeon considers a CDA at C5-C6, proximal to an existing C6-C7 ACDF, in hopes of reducing the risk of adjacent segment disease at C4-C5. Another clinical scenario is in the presence of two symptomatic adjacent cervical segments, a surgeon may consider fusing the segment with more severe spondylotic changes such as severe disc collapse and facet arthropathy while performing CDA at the adjacent, more mobile segment. While numerous studies have demonstrated excellent clinical outcomes of primary cervical disc replacement surgery, many questions regarding the biomechanics of CDA in a hybrid construct remain unanswered. PURPOSE (1) How is disc prosthesis motion response influenced by the presence of a fusion proximal or distal to the prosthesis? and (2) How does the number of fused levels in the hybrid construct affect the prosthesis motion? STUDY DESIGN/SETTING Biomechanical study using human cadaveric cervical spines. PATIENT SAMPLE Human cervical spine specimens (C2-T1, N=10, 46±16 years). OUTCOME MEASURES Segmental flexion-extension range of motion (ROM). METHODS Specimens were divided into two equal groups based on age, gender distribution, and preoperative mobility. Segmental motions were assessed under flexion and extension moments of 1.5 Newton-meters. In Group I, the arthroplasty was proximal to one- and two-level ACDF, while in Group 2, the arthroplasty was distal to one- and two-level ACDF. ACDF was performed using a PEEK cage and anterior plate and CDA was performed using the M6-C cervical disc prosthesis (Orthofix Medical, Inc). Within group comparisons were made using a repeated-measures ANOVA and paired-t test, whereas across group comparisons used 2-sample t-test. RESULTS Segment level of implantation: 20 segments underwent CDA. Ten discs were implanted at C4-C5, 5 at C5-C6, and 5 at C6-C7. The mean segmental ROM after CDA was 9.2±4.2 degrees. Segmental level of implantation did not influence the ROM (C4-C5: 8.6±3.7; C5-C6: 9.4±4.1; C6-C7: 10.0±6.1; p>0.7). Number of fused levels in the hybrid construct: The number of fused segments in the hybrid construct did not influence the ROM after CDA (1-level: 9.7±4.6 vs 2-level: 9.9±4.4; p=0.9). CDA proximal vs distal to fusion: CDA above a 1-level ACDF had ROM similar to CDA below a 1-level ACDF (9.4±4.1 degrees vs 10.0±6.1; p=0.76). This result also held for a prosthesis implanted above versus below a 2-level ACDF (9.9±4.6 vs 9.8±5.2; p=1.0). CDA in hybrid construct compared to intact: CDA in a hybrid construct had ROM similar to the ROM of the corresponding segment in the intact spine. This result held true for all hybrid constructs studied regardless of location of prosthesis above or below a fusion, and the number of fused levels. CONCLUSIONS This study simulated a scenario where the patient experiences the same moments before and after surgery. Some authors suggest patients maintain similar ROM before and after surgery. Likely, actual in vivo loading reflects a combination of the two approaches. Results of this study suggest that disc arthroplasty performed adjacent to a 1- or 2-level cervical fusion is likely to maintain the same degree of motion as a primary arthroplasty. These findings provide a cadaveric basis for future in vivo studies to validate these results. FDA DEVICE/DRUG STATUS M6C artificial cervical disc, Orthofix, Inc (Not approved for this indication)

A Novel Preoperative Radiographic Scoring System To Predict Postoperative Outcomes in Patients Undergoing Cervical Disc Replacement Surgery

Abstract INTRODUCTION The purpose of this study was to use a novel scoring system to quantify the level of degenerative change within the disc space, uncus, and facet joints, and determine the impact of worsening degenerative changes on postoperative outcome. METHODS Preoperative lateral and AP radiographs were collected and scored by 3 spine surgeons based on disc height, facet arthrosis, and uncovertebral joint degeneration. Each of the categories was scored from 0 to 2. These scores were separately used in the analysis to assess which component correlated with outcomes of surgery. An overall score for preoperative radiographic assessment was calculated as the sum of these 3 scores and also used in the analysis. Surgical outcomes were assessed by 5 patient reported outcomes measures (PROMs); Visual Analogue Scale (VAS) arm, VAS neck, Neck Disability Index (NDI), and Short Form 12 Physical health (SF12-P) and mental health (SF12-M). RESULTS Radiographs of 85 patients that underwent CDR were assessed. Of those, 60 were single-level and 25 were two-level surgeries. A total of 44 patients were deemed to have adequate follow up, while 41 patients were excluded from the analysis due to inadequate follow-up. Interrater reliability for radiographic assessment was good to excellent. The included patients had a mean follow-up of 8 mo, ranging from 6 to 24 mo. At latest follow-up, preoperative facet arthrosis showed a statistically significant correlation with NDI and VAS neck outcomes measures (P = .016, P = .013, respectively). However, disc height and uncovertebral degeneration did not correlate with any of the collected PROMs (P &gt; .05 for all). CONCLUSION Preoperative health of the facet joint at the surgical level had a significant impact on patient perceived neck pain and disability at the latest follow up. It is important for patient selection to be refined to reflect a focus on factors that can impair success of CDR surgery.

Friday, September 28, 2018 10:30 AM–12:00 PM abstracts: complications of cervical spine surgery: 155. Same day discharge after anterior cervical discectomy and fusion in suitable patients has similarly low readmission rates as admitted patients

BACKGROUND CONTEXT Outpatient ACDFs are being performed at an increasing rate and prior studies have shown similar complication and readmission rates when compared to traditional admission. However, the ideal patient for same day ACDF has yet to be identified. A multidisciplinary group at a tertiary academic center developed a protocol for patient selection and discharge for patients undergoing same day discharge ACDF with the aim of ensuring patient safety and reducing the likelihood of readmission. PURPOSE Our aim was to show that utilizing a standardized protocol to select patients for outpatient ACDF will result in a noninferior readmission rate compared to traditional overnight admission. STUDY DESIGN/SETTING Retrospective review of a prospectively implemented protocol. PATIENT SAMPLE A total of 434 patients undergoing one or two-level ACDF from March 2016 to March 2017 at a tertiary academic institution. OUTCOME MEASURES A total of 30 and 90 day readmission rates. METHODS A retrospective chart-review was performed to identify patients undergoing one or two level primary ACDF who were eligible for same day discharge (SDD) according to the institutional protocol. Patients undergoing cervical disc replacement, three or more level surgery, corpectomy, posterior or revision surgery were excluded. All patients underwent ACDF via the anterior approach with implants based on surgeon preference. Patients with identical surgery and discharge dates were grouped as SDD and admitted patients were grouped as same day admission (SDA). Using our electronic health record's analytics, readmissions in the 90-day postoperative period were identified. RESULTS A total of 434 patients underwent one or two level ACDF from March 2016 to March 2017 of which 126 patients were SDD and 308 were SDA. Due to the protocol, baseline characteristics such as age, operative time and time in the recovery room was significantly different between the two groups. In each group there was one readmission during the 30 day postoperative period and the SDA group had one additional readmission in the 90 day postoperative period. This resulted in an overall, noninferior readmission rate of 0.8% in the SDD group and 0.6% in the SDA group (p=.86). CONCLUSIONS Proper identification of patients suitable for outpatient ACDF using our protocol for patient selection and discharge results in a noninferior readmission rate.

Improvement of severe myalgic encephalomyelitis/chronic fatigue syndrome symptoms following surgical treatment of cervical spinal stenosis

BackgroundMyalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a potentially disabling disorder. Little is known about the contributors to severe forms of the illness. We describe three consecutive patients with severe ME/CFS whose symptoms improved after recognition and surgical management of their cervical spinal stenosis.MethodsAll patients satisfied clinical criteria for ME/CFS and orthostatic intolerance, and were later found to have cervical spinal stenosis. Overall function was assessed before and after surgery using the Karnofsky score and the SF-36 physical function subscale score.ResultsNeurological findings included > 3+ deep tendon reflexes in 2 of 3, a positive Hoffman sign in 2 of 3, tremor in 2 of 3, and absent gag reflex in 1 of 3. The cervical spine canal diameter in the three patients ranged from 6 to 8.5 mm. One had congenital cervical stenosis with superimposed spondylosis, and two had single- or two-level spondylosis. Anterior cervical disc replacement surgery in two patients and a hybrid anterior cervical disc fusion and disc replacement in the third was associated with a marked improvement in myelopathic symptoms, resolution of lightheadedness and hemodynamic dysfunction, improvement in activity levels, and improvement in global ME/CFS symptoms.ConclusionsThe prompt post-surgical restoration of more normal function suggests that cervical spine stenosis contributed to the pathogenesis of refractory ME/CFS and orthostatic symptoms. The improvements following surgery emphasize the importance of a careful search for myelopathic examination findings in those with ME/CFS, especially when individuals with severe impairment are not responding to treatment.

Heterotopic Ossification After Cervical Total Disc Replacement at 7 Years-Prevalence, Progression, Clinical Implications, and Risk Factors.

Heterotopic ossification (HO) is a known risk following cervical total disc replacement (CTDR) surgery, but the cause and effect of HO are not well understood. Reported HO rates vary, and few studies are specifically designed to report HO. The effects on outcomes, and the risk factors for the development of HO have been hypothesized and reported in small-population, retrospective analyses, using univariate statistics. Posthoc, multiple-phase analysis of radiographic, clinical, and demographic data for CTDR as it relates to HO was performed. HO was radiographically graded for 164 one-level and 225 two-level CTDR patients using the McAfee and Mehren system. Analysis was performed to correlate HO grades to clinical outcomes and to evaluate potential risk factors for the development of HO using demographics and baseline clinical measures. At 7 years, 1-level clinically relevant HO grades were 17.6% grade 3 and 11.1% grade 4. Two-level clinically relevant HO grades, evaluated using the highest patient grade, were 26.6% grade 3 and 10.8% grade 4. Interaction between HO and time revealed significance for neck disability index (NDI; P = .04) and Visual Analog Scale (VAS) neck pain (P = .02). When analyzed at each time point NDI was significant at 48-84 months and VAS neck at 60 months. For predictors 2 analyses were run; odds ratios indicated follow-up visit, male sex, and preoperative VAS neck pain are related to HO development, whereas hazard ratios indicated male sex, obesity, endplate coverage, levels treated, and preoperative VAS neck pain. This is the largest study to report HO rates, and related outcomes and risk factors. To develop an accurate predictive model, further large-scale analyses need to be performed. Based on the results reported here, clinically relevant HO should be more accurately described as motion-restricting HO until a definitive link to outcomes has been established.

131 - Clinical Implications and Risk Factors of Heterotopic Ossification at 7 Years after Cervical Total Disc Replacement

BACKGROUND CONTEXT: Heterotopic ossification (HO) is a known risk following cervical total disc replacement (CTDR) surgery, but potential risk factors and impacts on outcomes remain unknown. Reported HO rates vary, and few studies are specifically designed to report HO. The effects on outcomes, and the risk factors for development of HO have been hypothesized and reported in literature, but the studies included small populations, retrospective analyses, and the use of univariate statistics.

A 6-DOF parallel bone-grinding robot for cervical disc replacement surgery.

Artificial cervical disc replacement surgery has become an effective and main treatment method for cervical disease, which has become a more common and serious problem for people with sedentary work. To improve cervical disc replacement surgery significantly, a 6-DOF parallel bone-grinding robot is developed for cervical bone-grinding by image navigation and surgical plan. The bone-grinding robot including mechanical design and low level control is designed. The bone-grinding robot navigation is realized by optical positioning with spatial registration coordinate system defined. And a parametric robot bone-grinding plan and high level control have been developed for plane grinding for cervical top endplate and tail endplate grinding by a cylindrical grinding drill and spherical grinding for two articular surfaces of bones by a ball grinding drill. Finally, the surgical flow for a robot-assisted cervical disc replacement surgery procedure is present. The final experiments results verified the key technologies and performance of the robot-assisted surgery system concept excellently, which points out a promising clinical application with higher operability. Finally, study innovations, study limitations, and future works of this present study are discussed, and conclusions of this paper are also summarized further. This bone-grinding robot is still in the initial stage, and there are many problems to be solved from a clinical point of view. Moreover, the technique is promising and can give a good support for surgeons in future clinical work.

Cervical disc replacement surgery: indications, technique, and technical pearls.

Cervical disc replacement (CDR) is a surgical option for appropriately indicated patients, and high success rates have been reported in the literature. Complications and failures are often associated with patient indications or technical variables, and the goal of this review is to assist surgeons in understanding these factors. Several investigations have been published in the last 5years supporting the use of CDR in specific patient populations. CDR has been shown to be comparable or favorable to anterior cervical discectomy and fusion in several meta-analyses and mid-term follow-up studies. CDR was developed as a technique to preserve motion following a decompression procedure while minimizing several of the complications associated with fusion and posterior cervical spine procedures. Though success with cervical fusion and posterior foraminotomy has been well documented in the literature, high rates of mid- and long-term complications have been clearly established. CDR has also been associated with several complications and challenges with regard to surgical technique, though improvements in implant design have lead to an increase in utilization. Several devices currently exist and vary in terms of material, design, and outcomes. This review paper discusses indications, surgical technique, and technical pearls and reviews the CDR devices currently available.

Cervical disc replacement surgery: biomechanical properties, postoperative motion, and postoperative activity levels.

Cervical disc arthroplasty (CDA) is an evolving technique used in the treatment of cervical disc disease. To remain up to date on studies regarding its efficacy, we sought to answer three questions: What do biomechanical studies demonstrate in regard to the kinematics of CDA? How does CDA affect cervical motion? What are the postoperative activity levels of patients after cervical disc arthroplasty? 1) In regard to biomechanics, recent data suggests that CDA maintains motion while possibly altering facet biomechanics. 2) Radiographic data indicates a reliable maintenance of motion in the short and medium term. 3) Postoperative activity levels are assessed with clinical outcome data which demonstrate reliable improvement in pain and function. The data reviewed here establishes CDA as an efficacious treatment in the relief of symptoms from CDD. It is important to note however that an evaluation of CDA would benefit from more robust data, specifically in regards to long-term clinical outcomes.

Cervical spine alignment in disc arthroplasty: should we change our perspective?

The alignment at the cervical spine has been considered a determinant of degeneration at the adjacent disc, but this issue in cervical disc replacement surgery is poorly explored and discussed in this patient population. The aim of this systematic review is to compare anterior cervical fusion and total disc replacement (TDR) in terms of preservation of the overall cervical alignment and complications. A systematic review of the current literature was performed, together with the evaluation of the methodological quality of all the retrieved studies. In most of the retrieved studies, a tendency towards a more postoperative kyphotic alignment in TDR was reported. The reported mean complication rate was of 12.5 % (0-66.2 %). Complications associated with cervical prosthesis included heterotopic ossification, device migration, mechanical instability, failure, implant removal, reoperations and revision. Even though cervical disc arthroplasty leads to similar outcomes compared to arthrodesis in the middle term follow-up, no evidence of superiority of cervical TDR is available up to date. We understand that the overall cervical alignment after TDR tends towards the loss of lordosis, but only longer follow-up can determine its influence on the clinical results.

Biomechanical Analysis of Cervical Finite Element Model

The finite element method is often used in the field of biomechanical analysis. It can study the mechanical response of the internal organization without any experiments on the human body. The paper studies the biomechanics of the cervical spine by the method of finite element analysis. Firstly, the finite element model of the cervical spine including cervical vertebrae and soft tissue is constructed. Secondly, biomechanical analysis of cervical finite element model which is validated to be reasonable and reliable is completed. The results of the control group, the anterior cervical decompression and fusion surgery group, and the artificial cervical disc replacement surgery group are obtained to study the motion degree and ligament force of cervical spine. Thirdly, the summary of the biomechanical analysis of cervical finite element model is concluded.