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Cervical disc arthroplasty (CDA), also known as cervical artificial disc replacement, has become an alternative for the treatment of cervical spondylosis with radicular or myelopathic symptoms. However, there is limited literature regarding its complications and outcomes. We present two cases that developed C5 nerve palsy (C5P) following two-level CDA. Both patients presented with C5P in a delayed fashion with 2/5 and 1/5 deltoid weakness on MMT, respectively. Postoperative imaging did not demonstrate any spinal cord compression and symptoms resolved (5/5 on MMT) with conservative management in both cases. To our knowledge, these represent the first cases of delayed C5P after cervical arthroplasty reported in the literature. We performed a literature review to further enhance our knowledge regarding CDA. By understanding its pathophysiology and response to treatment, these cases can serve as a guide for spine surgeons and improve their future outcomes. [ABSTRACT FROM AUTHOR]

BackgroundMultilevel anterior cervical discectomy and fusion (mACDF) is the gold standard for multilevel spinal disease; although safe and effective, mACDF can limit regular spinal motion and contribute to adjacent segment disease (ASD). Hybrid surgery, composed of ACDF and cervical disc arthroplasty, has the potential to reduce ASD by retaining spinal mobility. This study examined the safety of hybrid surgery by utilizing administrative claims data to compare real-world rates of subsequent surgery and post-procedural hospitalization within populations of patients undergoing hybrid surgery versus mACDF for multilevel spinal disease.MethodsThis observational, retrospective analysis used the MarketScan Commercial and Medicare Database from July 2013 through June 2020. Propensity score matched cohorts of patients who received hybrid surgery or mACDF were established based on the presence of spinal surgery procedure codes in the claims data and followed over a variable post-period. Rates of subsequent surgery and post-procedural hospitalization (30- and 90-day) were compared between hybrid surgery and mACDF cohorts.ResultsA total of 430 hybrid surgery patients and 2,136 mACDF patients qualified for the study; average follow-up was approximately 2 years. Similar rates of subsequent surgery (Hybrid: 1.9 surgeries/100 patient-years; mACDF: 1.8 surgeries/100 patient-years) were observed for the two cohorts. Hospitalization rates were also similar across cohorts at 30 days post-procedure (Hybrid: 0.67% hospitalized/patient-year; mACDF: 0.87% hospitalized/patient-year). At 90 days post-procedure, hybrid surgery patients had slightly lower rates of hospitalization compared to mACDF patients (0.23% versus 0.42% hospitalized/patient-year; p

Study Design. A retrospective single-center study between January 2019 and January 2023. Objective. The role and contribution of drainage in the anterior approach to the cervical spine (cervicotomy) is much debated, motivated primarily by the prevention of retropharyngeal hematoma, so are there still any benefits to drainage? Background. The anterior approach to the cervical spine is a widespread and common procedure performed in almost all spine surgery departments for the replacement of cervical intervertebral discs and medullar or radicular decompression. The primary endpoint was the occurrence of symptomatic postoperative cervical hematoma. Patients and Methods. Four hundred thirty-one patients who had undergone cervical spine surgery by anterior cervicotomy for cervicarthrosis or cervical disc herniation (anterior cervical discectomy and fusion and anterior cervical disc replacement) were consecutively included. Patients were separated into 2 groups: (1) Group A, 140 patients (with postoperative drainage) and (2) Group B, 291 patients (without drainage). Results. The mean follow-up was 2.8 months. The 2 groups were comparable on all criteria, but there was a predominance of arthroplasty (P < 0.0001), use of anticoagulants/antiaggregants (P < 0.0001) and a greater number of stages (P < 0.0001) in group A. Therewere a total of 4/431 symptomatic postoperative hematomas (0.92%) in this study. Two hematomas occurred in group A (2/140, 1.4%) and 2 in group B (2/291, 0.68%; P < 0.0001). One patient in group A (0.71%) required surgical drainage for cavity hematoma revealed by marked dyspnea, swallowing, and neurological disorders. One case of hematoma diagnosed by dysphonia and neurological deficit was reported in group B (0.34%; P < 0.0001). Conclusions. The placement of a drain during anterior cervicotomy (anterior cervical discectomy and fusion/anterior cervical disc replacement) did not limit the occurrence of symptomatic postoperative hematoma. [ABSTRACT FROM AUTHOR]

Introduction: A recent study reported a 34% mid-term revision rate after M6-C™ cervical total disc replacement (CTDR) for wear-related osteolysis. Here, we aim to investigate the prevalence, risk factors, and radiographic characteristics of periprosthetic bony changes and implant failure of the M6-C™ artificial disc. Methods: We retrospectively analysed radiographic (conventional X-ray, CT scan) and clinical outcomes (EQ-5D-5L, Neck Disability Index (NDI), and Visual Analog Scale (VAS) for neck and arm pain) data collected during routine follow-up of patients who underwent CTDR with the M6-C™ between 2011 and 2015. Results: In total, 85 patients underwent CTDR with the M6-C™. Follow-up data were available for 43 patients (54% female, mean age 44 years) with 50 implants and a mean follow-up of 8.1 years (6.5–11 years). Implant failure with the presence of severe osteolysis was identified in 5 (12%) patients who were all male (p = 0.016) and implanted at the C5/6 level (p = 0.11). All failed implants required revision surgery. The overall prevalence of osteolysis was 44% (22/50 implants) and 34% (17/50 implants) for significant heterotopic ossification. Patients with high-grade osteolysis showed higher VAS arm pain (p = 0.05) and lower EQ-5D-VAS health VAS (p = 0.03). Conclusion: We report a lower reoperation rate for failed M6-C™ implants than previously published, but confirmed that osteolysis and heterotopic ossification are common following CTDR with the M6-C™ and may be asymptomatic. Therefore, we strongly recommend ongoing clinical and radiographic monitoring after CTDR with the M6-C™, particularly for male patients implanted at the C5/6 level. [ABSTRACT FROM AUTHOR]

Study design: Clinical observational study. Objective: The ROTAIO® cervical disc prosthesis is a novel unconstrained implant with a variable center of rotation aiming at physiological motion. The objective of this multicenter prospective trial was to evaluate clinical outcome and complications within 2 years. Material and Methods: 120 patients (72 females and 48 males with median age of 43.0 years [23-60 yrs] underwent ACDA (ROTAIO®, SIGNUS Medical, Alzenau, Germany) and were prospectively followed for 24 months. Preoperative complaints were mainly associated with radiculopathy (n = 104) or myelopathy (n=16). There were 108 monosegmental and 12 bisegmental procedures including 6 hybrid constructs. Clinical outcome was evaluated at 3, 12 and 24 months in 100%, 96% and 77% of the cohort by VAS, NDI, WL-26, Patient's Satisfaction Index (PSI), SF-36, Nurick Score, mJOA, Composite Success Rate, complications, patient's overall satisfaction and analgesics use. Results: Highly significant clinical improvements were observed according to NDI and VAS (P <.0001 (arm); P <.001 (neck); P =.002 (head)) at all time points. Analgetic use could be reduced in 87.1 to 95.2%. Doctor's visits have been reduced in 93.8% after 24 months. Patient's overall satisfaction was high with 78.4 to 83.5% of patients. The composite success rate was 77.5% after 12 months and 76.9% after 24 months. There were no major complications in this series. Slight subsidence of the prosthesis was observed in 2 patients and 3 patients demonstrated fusion after 24 months. 2 patients developed symptomatic foraminal stenosis, so that implant removal and fusion was performed resulting in a revision rate of 1.7% in 2 years. Conclusion: The ROTAIO® cervical disc prosthesis is a safe and efficient treatment option for symptomatic degenerative disc disease demonstrating highly significant clinical improvement and high patient's overall satisfaction with very low revision rates at 2 years. [ABSTRACT FROM AUTHOR]

Objective. To study the effect of arthroplasty and anterior interbody fusion in the cervical spine on degenerative changes in the adjacent intervertebral joints. Material and Methods. A retrospective cohort study included 46 patients (22 with cervical total disc arthroplasy – CTDA, and 24 with anterior cervical discectomy and fusion – ACDF) with symptoms of cervical spondylogenic compression myelopathy and/or radiculopathy. The degree of degeneration of facet joints adjacent to the operated segments was evaluated 12 months after surgical treatment. Degenerative changes in the cervical spine were assessed using CT according to the Okamoto classification. Vidar Dicom Viewer 3.2 software was used to view images and evaluate intervertebral joints. Statistical processing was performed using IBM SPSS Statistics 23. Data were presented as median and 25th and 75th percentiles – Me [Q1; Q3]. Results. The mean age of patients in both groups was 47 [39; 52] years (Mann – Whitney U-test, p = 0.047). In the ACDF group it was 48 [42; 55] years and in the CTDA group – 42 [36; 52] years. Comparison of degenerative changes in the ACDF group before and after treatment (Wilcoxon analysis) showed a statistically significant difference in the cranial (p = 0.023), and caudal (p = 0.001) joints, with the progression of degeneration degree. In the CTDA group, no difference between pre- and post-treatment degeneration degree (Wilcoxon analysis) was found in either cranial joints (p = 0.157) or caudal joints (p = 0.161). Conclusion. Surgeries to stabilize spinal segments in degenerative diseases undeniably affect the development of the adjacent level syndrome. However, the use of endoprosthetic technology makes it possible to aggravate the degree of degenerative changes in the intervertebral joints of adjacent segments to a lesser extent.

Cervical angina is an often-overlooked etiology of noncardiac chest pain that may mimic true angina pectoris but is due to cervical spine disease. Diagnosis can be difficult, and treatment ranges from conservative therapy to surgical management. However, of patient's refractory to conservative therapy, approximately ninety percent experience postoperative relief of angina symptoms. Here, we present a case report on cervical angina and performed a systematic review of the literature. A 34-year-old male with prior surgery for thoracic outlet syndrome presented with persistent anterior neck and chest pain as well as posterior left scapular and upper lateral arm pain. The pain was refractory to 12 months of conservative therapy. Cardiac workup was negative and cervical spine imaging revealed a C6-7 herniation with neuroforaminal stenosis. A systematic literature search was conducted in PubMed, Web of Science, and Cochrane databases from database inception to April 2020. Studies reporting cervical level, average symptom duration, location of pain, and postoperative pain improvement were included. The patient's atypical symptoms were completely resolved after C6-7 anterior cervical discectomy and arthroplasty. To our knowledge, this is the first study which reports on the use of arthroplasty in the treatment of cervical angina. The systematic review included 11 articles from 1989-2020 consisting of 1,186 total patients and 109 patients (age range, 36-84 years; 60.7% male) meeting inclusion criteria. Symptom duration range was 2 days to 90 months, with the most common location of pain being localized to the anterior chest wall (66.7% of patients). All patients (100%) had postoperative resolution of their pain symptoms. The most common herniation level was C6-7 (87.3% of patients). We conclude that a broad and multidisciplinary approach is necessary for the diagnosis and management of noncardiac chest pain. When cervical disease is identified as the underlying cause for the angina-like pain, conservative therapy should be sought. Refractory cases should be treated surgically depending on the cervical pathology.

Abstract Background Multilevel anterior cervical discectomy and fusion (mACDF) is the gold standard for multilevel spinal disease; although safe and effective, mACDF can limit regular spinal motion and contribute to adjacent segment disease (ASD). Hybrid surgery, composed of ACDF and cervical disc arthroplasty, has the potential to reduce ASD by retaining spinal mobility. This study examined the safety of hybrid surgery by utilizing administrative claims data to compare real-world rates of subsequent surgery and post-procedural hospitalization within populations of patients undergoing hybrid surgery versus mACDF for multilevel spinal disease. Methods This observational, retrospective analysis used the MarketScan Commercial and Medicare Database from July 2013 through June 2020. Propensity score matched cohorts of patients who received hybrid surgery or mACDF were established based on the presence of spinal surgery procedure codes in the claims data and followed over a variable post-period. Rates of subsequent surgery and post-procedural hospitalization (30- and 90-day) were compared between hybrid surgery and mACDF cohorts. Results A total of 430 hybrid surgery patients and 2,136 mACDF patients qualified for the study; average follow-up was approximately 2 years. Similar rates of subsequent surgery (Hybrid: 1.9 surgeries/100 patient-years; mACDF: 1.8 surgeries/100 patient-years) were observed for the two cohorts. Hospitalization rates were also similar across cohorts at 30 days post-procedure (Hybrid: 0.67% hospitalized/patient-year; mACDF: 0.87% hospitalized/patient-year). At 90 days post-procedure, hybrid surgery patients had slightly lower rates of hospitalization compared to mACDF patients (0.23% versus 0.42% hospitalized/patient-year; p

Study Design Retrospective cohort. Purpose To evaluate the validity of established severity thresholds for Neck Disability Index (NDI) among patients undergoing anterior cervical discectomy and fusion (ACDF) or cervical disc arthroplasty (CDA). Overview of Literature Few studies have examined the validity of established NDI threshold values among patients undergoing ACDF or CDA. Methods A surgical database was reviewed to identify patients undergoing cervical spine procedures. Demographics, operative characteristics, comorbidities, NDI, Visual Analog Scale (VAS), and 12-item Short Form (SF-12) physical and mental composite scores (PCS and MCS) were recorded. NDI severity was categorized using previously established threshold values. Improvement from preoperative scores at each postoperative timepoint and convergent validity of NDI was evaluated. Discriminant validity of NDI was evaluated against VAS neck and arm and SF-12 PCS and MCS. Results All 290 patients included in the study demonstrated significant improvements from baseline values for all patient-reported outcome measures (PROMs) at all postoperative timepoints (p

Abstract Background Cervical disc prostheses are used to preserve motion after discectomy, but they should also provide a near-physiological qualitative motion pattern. Nevertheless, they come in many completely different biomechanical concepts. This caused us to perform an in-vivo MR-based biomechanical study to further investigate cervical spine motion with the aim to gain new information for improving the design of future cervical arthroplasty devices. Methods Fifteen healthy volunteers underwent MRI-investigation (in order to avoid radiation exposure) of their cervical spines from C3 to C7; for each segment centers of rotation (COR) for flexion / extension were determined from 5 different positions, and CORs for lateral bending from 3 different positions. The motion path of the COR is then described and illustrated in relation to the respective COR for maximum flexion / extension or lateral bending, respectively, and the findings are translated into implications for a better biomechanical prosthesis-design. Results The COR for flexion / extension does not remain constant during motion. The CORs for the respective motion intervals were always found at different positions than the COR for maximum flexion /extension showing that the COR moves both along the x- and the y-axis throughout flexion / extension. For lateral bending a completely independent COR was found above disc-level. Conclusion Flexion / extension is not a simple circular motion. Disc prostheses need a variable COR for flexion / extension below disc level with the capability to move both along the x- and the y-axis during motion, plus a second completely independent COR for lateral bending above disc level to closely replicate in-vivo motion. These findings are important for improving the biomechanical design of such devices in the future.

Purpose: We sought to characterize trends in demographics, comorbidities, and postoperative complications among patients undergoing primary and revision cervical disc replacement (pCDR/rCDR) procedures. Methods: In this retrospective database study, the Premier Healthcare database was queried from 2006 to 2019. Annual proportions or medians were calculated for patient and hospital characteristics, comorbidities, and postoperative complications associated with CDR surgery. Trends were assessed using linear regression analyses with year of service as the sole predictor. Results: A total of 16,178 pCDR and 758 rCDR cases were identified, with a median (IQR) age of 46 (39; 53) and 51 (43; 60) years among patients, respectively. The annual number of both procedures increased between 2006 and 2019, from 135 to 2220 for pCDR (p < 0.001), and from 17 to 49 for rCDR procedures (p < 0.001), with radiculopathy being the main indication for surgery in both groups. Mechanical failure was identified as a major indication for rCDR procedures with an increase over time (p = 0.002). Baseline patient comorbidity burden (p = 0.045) and complication rates (p < 0.001) showed an increase. For both procedures, an increase in outpatient surgeries and procedures performed in rural hospitals was seen (pCDR: p = 0.045; p = 0.006; rCDR: p = 0.028; p = 0.034). Conclusion: PCDR and rCDR procedures significantly increased from 2006 to 2019. At the same time, comorbidity burden and complication rates increased, while procedures were more often performed in an outpatient and rural setting. The identification of these trends can help guide future practice and lead to further areas of research. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort. Purpose: To evaluate the validity of established severity thresholds for Neck Disability Index (NDI) among patients undergoing anterior cervical discectomy and fusion (ACDF) or cervical disc arthroplasty (CDA). Overview of Literature: Few studies have examined the validity of established NDI threshold values among patients undergoing ACDF or CDA. Methods: A surgical database was reviewed to identify patients undergoing cervical spine procedures. Demographics, operative characteristics, comorbidities, NDI, Visual Analog Scale (VAS), and 12-item Short Form (SF-12) physical and mental composite scores (PCS and MCS) were recorded. NDI severity was categorized using previously established threshold values. Improvement from preoperative scores at each postoperative timepoint and convergent validity of NDI was evaluated. Discriminant validity of NDI was evaluated against VAS neck and arm and SF-12 PCS and MCS. Results: All 290 patients included in the study demonstrated significant improvements from baseline values for all patient-reported outcome measures (PROMs) at all postoperative timepoints (p <0.001) except SF-12 MCS at 2 years (p =0.393). NDI showed a moderate-to-strong correlation (r =0.419) at most timepoints for VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS (p <0.001, all). NDI severity categories demonstrated significant differences in mean VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS at all timepoints (p <0.001, all). Differences between NDI severity groups were not uniform for all PROMs. VAS neck values demonstrated significant intergroup differences at most timepoints, whereas SF-12 MCS showed significantly different values between most severity groups. Conclusions: Neck disability is strongly correlated with neck and arm pain, physical function, and mental health and demonstrates worse outcomes with increasing severity. Previously established severity categories may be more applicable to pain than physical function or mental health and may be more uniformly applied preoperatively for cervical spine patients. [ABSTRACT FROM AUTHOR]

Recently, many different types of artificial discs have been introduced to persevere the biomechanical behavior of the cervical spine. This study compares the biomechanical behavior of single- and double-level cervical disc arthroplasty, that is "Prestige LP and Mobi-C" on the index and adjacent segment. A three-dimension finite element model of C2-C7 was developed and validated. In single-level prostheses, the Prestige LP or Mobi-C was implanted in the segment C5-C6, while the double-level arthroplasty was integrated at both segments C4-C5 and C5-C6 in the FE model. The intact FE and prosthesis-modified models were constrained from the inferior endplate of the vertebra C7 and applied a compressive load of 73.6 N with a moment load of 1 Nm on the odontoid process of the vertebra C2 to produce flexion/extension, lateral bending, and axial rotation. The prosthesis-modified model's range of motion and intradiscal pressure were determined and compared to the intact model. Also examined the impact of the prostheses on the stress at the bone-implant interface. The range of motion of the implanted segments in both single- and double-levels arthroplasty was increased while that of the adjacent segment of implanted segments decreased. The intradiscal pressure in both levels of arthroplasty was greater than in the intact model. In conclusion, Mobi-C's cervical prostheses could better preserve the normal range of motion and maintain intradiscal pressure than the Prestige LP. Graphical abstract [ABSTRACT FROM AUTHOR]

Patients with cervical spondylosis often present with concurrent 'atypical symptoms' of unknown etiology that have been associated with cervical spondylotic disease, including dizziness, headache, nausea, tinnitus, blurred vision, palpitations, and memory and gastrointestinal disturbances. Few studies have addressed whether surgical intervention to treat classic symptoms of cervical spondylosis can also effectively alleviate atypical symptoms. Accordingly, the purpose of this study is to compare the ability of cervical arthroplasty (CA) and anterior cervical discectomy and fusion (ACDF) to alleviate atypical symptoms associated with cervical spondylosis. A retrospective analysis of 140 patients with cervical spondylosis and associated atypical symptoms was performed. Atypical symptoms were defined vertigo, headache, nausea and vomiting, tinnitus, blur vision, palpitation, hypomnesia, and gastroenteric disturbances not otherwise explained by medical comorbidities. Seventy-eight patients (55.7%) underwent ACDF and 62 (44.3%) patients underwent CA. Demographics, surgical characteristics, patient reported outcome measures (PROMs), radiographs, complication rates, and resolution in atypical symptoms were recorded and compared between groups. Atypical symptoms were assessed using a 20-point system. All the patients had a minimum of five years follow-up. VAS, SF-36, JOA, and NDI scores improved significantly in all the patients (p < 0.001). At the last follow-up, the fusion rate was 97% in the ACDF group. Atypical symptoms improved in both groups (p < 0.001), although the ACDF group demonstrated greater improvement in headache and vertigo resolution compared to the CA group (p < 0.0001). While both ACDF and CA are effective in alleviating atypical symptoms associated with cervical spondylosis, ACDF demonstrated greater improvements in atypical symptoms. [ABSTRACT FROM AUTHOR]

Introduction: The correlation between cervical alignment and clinical outcome of total disc replacement (TDR) surgery is arguable. We believe that this conflict exists because the parameters that influence the biomechanics of the cervical spine are not well understood, specifically the effect of TDR on different cervical alignments. Methods: A validated osseo-ligamentous model from C2-C7 was used in this study. The C2-C7 Cobb angle of the base model was modified to represent: lordotic (−10°), straight (0°), and kyphotic (+10°) cervical alignment. The TDR surgery was simulated at the C5-C6 segment. The range of motion (ROM), intradiscal pressure, annular stresses, and facet loads were computed for all the models. Results: The ROM results demonstrated kyphotic alignment after TDR surgery to be the most mobile when compared to intact base model (41% higher in flexion–extension, 51% higher in lateral bending, and 27% higher in axial rotation) followed by straight and lordotic alignment, respectively. The annular stresses for the kyphotic alignment when compared to intact base model were higher at the index level (33% higher in flexion–extension and 48% higher in lateral bending) compared to other alignments. The lordotic model demonstrated higher facet contact forces at the index level (75% higher in extension than kyphotic alignment, 51% higher in lateral bending than kyphotic alignment, and 78% higher in axial rotation than kyphotic alignment) when compared among the three alignment models. Conclusion: Preoperative cervical alignment should be an integral part of surgical planning for TDR surgery as different cervical alignments may significantly alter the postsurgical outcomes.

Objective: To evaluate the biological function of cervical subtotal discectomy prosthesis (CSDP) implantation in a non-human primate model.Methods: A CSDP was tested for cytocompatibility and osseointegration capacity before implantation in non-human primates. Subsequently, the CSDP was improved based on three-dimensional CT measurements of the non-human primate cervical spine. Eight cynomolgus monkeys were selected for removal of the intervertebral disc and lower endplate of the C5/6 segment to complete the model construction for CSDP implantation. In 18-month follow-up, physiological indices, radiology, and kinematics were assessed to estimate the biological function of the CSDP in non-human primates, including biosafety, osseointegration, and biomechanics.Results: Co-cultured with the CSDP constituent titanium alloy (Ti6Al4V-AO), the mouse embryo osteoblast precursor cell MC3T3-E1 obtained extended adhesion, remarkable viability status, and cell proliferation. After implantation in the mouse femur for 28 days, the surface of Ti6Al4V-AO was covered by a large amount of new cancellous bone, which formed further connections with the femur cortical bone, and no toxicity was detected by blood physiology indices or histopathology. After completing implantation in primate models, no infection or osteolysis was observed, nor was any subsidence or displacement of the CSDP observed in CT scans in the 18-month follow-up. In particular, the interior of the cervical vertebra fixation structure was gradually filled with new trabecular bone, and the CSDP had achieved fixation and bony fusion in the vertebral body at 1 year post-operation. Meanwhile, no signs of inflammation, spinal cord compression, adjacent segment degeneration, or force line changes were observed in subsequent MRI observations. Moreover, there were no pathological changes of the joint trajectory, joint motion range, stride length, or the stance phase ratio revealed in the kinematics analysis at 3, 6, 12, or 18 months after CSDP implantation.Conclusion: We successfully designed a new cervical subtotal discectomy prosthesis and constructed an excellent non-human primate implantation model for the evaluation of subtotal disc replacement arthroplasty. Furthermore, we demonstrated that CSDP had outstanding safety, osseointegration capacity, and biomechanical stability in a non-human primate model, which might be a new choice in the treatment of cervical disc diseases and potentially change future outcomes of degenerative cervical diseases.

Anterior cervical discectomy and fusion (ACDF) is the gold standard approach for surgical management of many manifestations of cervical spine pathology. In recent years, total disc replacement (TDR) has emerged as a motion preserving modality that is proposed to decrease the rate of adjacent segment disease (ASD). In patients with multi-level disease, hybrid constructs with ACDF at 1 level and TDR at an adjacent level have been performed with success. While these contiguous hybrid constructs have been shown to reduce rates of ASD, there is a paucity of literature regarding non-contiguous hybrid constructs. 1-3 When performing anterior cervical surgery with the intention of completing an ACDF and a TDR at non-contiguous levels, there are multiple unique technical aspects of the exposure and discectomy that must be taken into consideration. Here we present a technique report of a 59-year-old male patient who had non-contiguous cervical spondylosis who underwent a successful C2/C3 ACDF and C4/C5 and C5/C6 TDR. Multiple surgical options were discussed with the patient including multi-level anterior fusion, posterior laminoplasty, and posterior decompression and fusion. 4-6 Following discussion of risks, benefits, and alternatives, the patient consented to the anterior hybrid approach. The patient underwent an uncomplicated hybrid anterior fusion and disc arthroplasty and was discharged home on postoperative day 1. The present video serves as technique guide and case study of a non-contiguous construct with satisfactory motion preservation and clinical outcome (Video 1). [ABSTRACT FROM AUTHOR]

Cervical disc replacement is an alternative option to an anterior cervical discectomy and fusion for cervical spine degenerative disease. We present the first reported case of a progressively worsening symptomatic spinal cord compression secondary to migration of the nucleus from a Mobi-C total disc replacement. [ABSTRACT FROM AUTHOR]

Although cervical disc arthroplasty (CDA) has reportedly been associated with similarly low incidences of complications to anterior cervical discectomy and fusion, the phenomenon of anterior bone loss (ABL) is unique to CDA and has only recently gained notice. This study thus aimed to investigate the incidence of ABL and its correlation with cervical alignment post-operation. Consecutive patients who received CDA for herniated disc or spondylosis were retrospectively reviewed. The development and extent of ABL was detected by comparison of preoperative and postoperative serial images for the relative position of the anterior vertebral body with the CDA devices and graded into 3 levels: grade 1 (minor bone loss), grade 2 (anterior portion of the vertebral body without exposure of the artificial disc), and grade 3 (anterior portion of the vertebral body with exposure of the device). A total of 41 patients were analyzed with a mean follow-up of 24.1 months. Under serial radiologic examinations during follow-up, all patients (41 of 41 = 100%) had bone loss of various degrees, with grade 3 ABL the most common (30 of 41 = 73.1%). There were 8 and 3 patients who had grades 2 and 1 ABL, respectively. The changes of the Cobb angle (ΔCobb) trended towards higher grades of ABL. During the mean follow-up of 2 years, ABL was a common radiologic finding. More than half of the patients (26 of 41, 63.4%) in the series gained cervical lordosis (ΔCobb >0) after CDA. These patients with increased cervical lordosis (ΔCobb >0) after CDA had higher grades of ABL. [ABSTRACT FROM AUTHOR]

Introduction: The correlation between cervical alignment and clinical outcome of total disc replacement (TDR) surgery is arguable. We believe that this conflict exists because the parameters that influence the biomechanics of the cervical spine are not well understood, specifically the effect of TDR on different cervical alignments. Methods: A validated osseo-ligamentous model from C2-C7 was used in this study. The C2-C7 Cobb angle of the base model was modified to represent: lordotic (−10°), straight (0°), and kyphotic (+10°) cervical alignment. The TDR surgery was simulated at the C5-C6 segment. The range of motion (ROM), intradiscal pressure, annular stresses, and facet loads were computed for all the models. Results: The ROM results demonstrated kyphotic alignment after TDR surgery to be the most mobile when compared to intact base model (41% higher in flexion–extension, 51% higher in lateral bending, and 27% higher in axial rotation) followed by straight and lordotic alignment, respectively. The annular stresses for the kyphotic alignment when compared to intact base model were higher at the index level (33% higher in flexion–extension and 48% higher in lateral bending) compared to other alignments. The lordotic model demonstrated higher facet contact forces at the index level (75% higher in extension than kyphotic alignment, 51% higher in lateral bending than kyphotic alignment, and 78% higher in axial rotation than kyphotic alignment) when compared among the three alignment models. Conclusion: Preoperative cervical alignment should be an integral part of surgical planning for TDR surgery as different cervical alignments may significantly alter the postsurgical outcomes. [ABSTRACT FROM AUTHOR]

Objective To perform a systematic literature review on revision surgeries at the index level after cervical disc arthroplasty (CDA) failure. Methods A systematic literature review was performed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Prospective studies on patients who required a secondary surgery after CDA failure were included for analysis. The minimum follow-up for these studies was 5 years. Results Out of 864 studies in the original search group, a total of 20 studies were included. From a total of 4,087 patients, 161 patients required a reoperation at the index level. A total of 170 surgeries were performed, as some patients required multiple surgeries. The most common secondary procedures were anterior cervical discectomy and fusion (ACDF) (68%, N = 61) and posterior cervical fusion (15.5%, N = 14), followed by other reoperation (13.3%, N = 12). The associated outcomes for those who required a revision surgery were rarely mentioned in the included literature. Conclusion The long-term revision rate at the index level of failed CDA surgery was 3.9%, with a minimum 5-year follow-up. ACDF was the most commonly performed procedure to salvage a failed CDA. Some patients who required a new surgery after CDA failure may require a more extensive salvage procedure and even subsequent surgeries.

Anterior dural tears complicated by cerebrospinal fluid (CSF) leakage with anterior meningocele are rare. Indeed, in the literature, cases are described during anterior arthrodesis, but no cases of post-cervical arthroplasty are described. The management of this type of complication is poorly described and not consensual. We present a case of a patient who underwent cervical arthroplasty complicated by an anterior meningocele at 1 month after the first surgery. Imaging revealed a compressive anterior meningocele in relation to the clinically progressive worsening. Revision surgery consisted of a combination of closure of the gap with a fatty patch covered with a TachoSil patch, followed by reinsertion of a new cervical prosthesis. At the last follow-up at 1 year, the patient showed no residual effects of the complication, and the mobility of the disc prosthesis was not impaired by it. Clinical results of the arthroplasty are also very satisfactory. Although these types of complications are rare, it is important to have a consensus on the management of anterior meningocele. In our experience, TachoSil appears to be a satisfactory option for the management of these complications. [ABSTRACT FROM AUTHOR]

Background: Cervical disc prostheses are used to preserve motion after discectomy, but they should also provide a near-physiological qualitative motion pattern. Nevertheless, they come in many completely different biomechanical concepts. This caused us to perform an in-vivo MR-based biomechanical study to further investigate cervical spine motion with the aim to gain new information for improving the design of future cervical arthroplasty devices.Methods: Fifteen healthy volunteers underwent MRI-investigation (in order to avoid radiation exposure) of their cervical spines from C3 to C7; for each segment centers of rotation (COR) for flexion / extension were determined from 5 different positions, and CORs for lateral bending from 3 different positions. The motion path of the COR is then described and illustrated in relation to the respective COR for maximum flexion / extension or lateral bending, respectively, and the findings are translated into implications for a better biomechanical prosthesis-design.Results: The COR for flexion / extension does not remain constant during motion. The CORs for the respective motion intervals were always found at different positions than the COR for maximum flexion /extension showing that the COR moves both along the x- and the y-axis throughout flexion / extension. For lateral bending a completely independent COR was found above disc-level.Conclusion: Flexion / extension is not a simple circular motion. Disc prostheses need a variable COR for flexion / extension below disc level with the capability to move both along the x- and the y-axis during motion, plus a second completely independent COR for lateral bending above disc level to closely replicate in-vivo motion. These findings are important for improving the biomechanical design of such devices in the future. [ABSTRACT FROM AUTHOR]

Cervical angina is an often-overlooked etiology of noncardiac chest pain that may mimic true angina pectoris but is due to cervical spine disease. Diagnosis can be difficult, and treatment ranges from conservative therapy to surgical management. However, of patient’s refractory to conservative therapy, approximately ninety percent experience postoperative relief of angina symptoms. Here, we present a case report on cervical angina and performed a systematic review of the literature. A 34-year-old male with prior surgery for thoracic outlet syndrome presented with persistent anterior neck and chest pain as well as posterior left scapular and upper lateral arm pain. The pain was refractory to 12 months of conservative therapy. Cardiac workup was negative and cervical spine imaging revealed a C6–7 herniation with neuroforaminal stenosis. A systematic literature search was conducted in PubMed, Web of Science, and Cochrane databases from database inception to April 2020. Studies reporting cervical level, average symptom duration, location of pain, and postoperative pain improvement were included. The patient's atypical symptoms were completely resolved after C6–7 anterior cervical discectomy and arthroplasty. To our knowledge, this is the first study which reports on the use of arthroplasty in the treatment of cervical angina. The systematic review included 11 articles from 1989–2020 consisting of 1,186 total patients and 109 patients (age range, 36–84 years; 60.7% male) meeting inclusion criteria. Symptom duration range was 2 days to 90 months, with the most common location of pain being localized to the anterior chest wall (66.7% of patients). All patients (100%) had postoperative resolution of their pain symptoms. The most common herniation level was C6–7 (87.3% of patients). We conclude that a broad and multidisciplinary approach is necessary for the diagnosis and management of noncardiac chest pain. When cervical disease is identified as the underlying cause for the angina-like pain, conservative therapy should be sought. Refractory cases should be treated surgically depending on the cervical pathology.

Abstract Background In cervical arthroplasty, qualitative motion analysis generally investigates the position of the center of rotation (COR) before and after surgery. But is the pre-op COR suitable as reference? We believe that only a comparison against healthy individuals can answer whether a physiological motion pattern has been achieved. The aim of our study was to examine how the COR for flexion/extension after insertion of 3 biomechanically completely different types of disc prostheses compares to healthy volunteers, and whether and how prosthesis design contributes to a more natural or maybe even worse motion pattern. Methods In 15 healthy volunteers, MRI in flexion and in extension was taken, and the coordinates for the CORs (COR-HV) from C3 to C7 were determined. Then pre- and post-op flexion/extension x-rays from 30 patients with a one-level disc prosthesis underwent analysis for determination of COR from C3 to C7; 10 patients who received a Bryan, a Prestige STLP, or a Discover prosthesis were chosen, respectively. Change of post-op COR position was investigated in relation to the COR-HV. Results The pre-operative COR is not congruent with the COR found in healthy subjects and therefore cannot be used as reference for investigation whether a disc prosthesis resembles natural motion. However, the comparison with healthy individuals shows that prosthesis insertion can change the coordinates of the COR to any direction in all levels from C3/4 to C6/7 regardless of the operated segment. Prostheses with flexible biomechanical properties can contribute to shift the COR toward normal, but devices with unphysiological biomechanical design, like fixed ball socket designs, for instance, can make the motion pattern even worse. Conclusions Even if the small cohorts in our study do not allow strong conclusions, it seems that in cervical arthroplasty, the biomechanical concept of the prosthesis has a significant impact whether a near-physiological motion pattern can be achieved or not. As it is a rumor but not scientifically proven that prosthesis design has no influence on clinical outcome, surgeons should only choose devices with flexible biomechanical properties for disc replacement.

IntroductionThere is increasing interest in the role of cervical total disc replacement (TDR) as an alternative to anterior cervical discectomy and fusion (ACDF). Multiple prospective randomized studies with minimum 2 year follow-up have shown TDR to be at least as safe and effective as ACDF in treating symptomatic degenerative disc disease at a single level. The purpose of this study was to compare outcomes of cervical TDR using the Mobi-C(®) with ACDF at 5-year follow-up.MethodsThis prospective, randomized, controlled trial was conducted as a Food and Drug Administration regulated Investigational Device Exemption trial across 23 centers with 245 patients randomized (2:1) to receive TDR with Mobi-C(®) Cervical Disc Prosthesis or ACDF with anterior plate and allograft. Outcome assessments included a composite overall success score, Neck Disability Index (NDI), visual analog scales (VAS) assessing neck and arm pain, Short Form-12 (SF-12) health survey, patient satisfaction, major complications, subsequent surgery, segmental range of motion, and adjacent segment degeneration.ResultsThe 60-month follow-up rate was 85.5% for the TDR group and 78.9% for the ACDF group. The composite overall success was 61.9% with TDR vs. 52.2% with ACDF, demonstrating statistical non-inferiority. Improvements in NDI, VAS neck and arm pain, and SF-12 scores were similar between groups and were maintained from earlier follow-up through 60 months. There was no significant difference between TDR and ACDF in adverse events or major complications. Range of motion was maintained with TDR through 60 months. Device-related subsequent surgeries (TDR: 3.0%, ACDF: 11.1%, p

We sought to determine the safety and effectiveness of the Flexible Cervical Implant in 1- or 2-level cervical segments. Retrospective data collection was carried out on consecutive patients who underwent the implantation of the Flexible Cervical Implant in a local private health institution. Demographics, clinical pictures, magnetic resonance images, x-ray images, technical considerations, and postoperative clinical results were reviewed. Twelve patients were treated with 15 implants. The mean age was 57.5 years (range 28–81), and 6 patients were males. The most common level was C5/C6 (7 cases). Radicular pain was the main symptom in all patients. Short-term postoperative clinical outcomes showed improvement in the visual analog scale (VAS) and the Neck Disability Index (NDI). The median VAS score for radicular pain improved from 6 to 2 (P < 0.001), whereas the median NDI showed a significant improvement from 25 to 5 (P < 0.001). No implant-related complications were reported. The mean follow-up was 7.3 months. The newly developed Flexible Cervical Implant was safe and effective in terms of morbidity and improvement in clinical outcomes. This new cervical artificial disk is promising, and further long-term clinical and radiologic follow-up is needed to determine its benefits. [ABSTRACT FROM AUTHOR]

Background Cervical arthroplasty with artificial cervical disks has gained popularity as an alternative to anterior discectomy and fusion. The main advantages of disk arthroplasty include maintenance of the range of movement, restitution of disk height and spinal alignment, and reduction of adjacent segment degeneration (ASD). In this article, we aimed to assess the outcomes of the use of a keel-less prosthesis. Material and Methods We included all the patients who underwent single-level cervical arthroplasties with the Discocerv Cervidisc Evolution for "soft" disk herniation. Clinical assessment included Neck Disability Index (NDI) and visual analog scale (VAS) for neck and arm pain. Radiologic studies investigated the occurrence of ASD and system failure or subsidence. The reoperation rate was also recorded. Results The study included 35 patients (14 men and 21 women; mean age: 42.5 years; mean follow-up: 57.8 months). There was a significant decrease in VAS neck and VAS arm scores, which went from 7.2 and 6.9 preoperatively to 2.2 and 1.7 postoperatively, 2.2 and 1.6 at 6 months, 2.0 and 1.8 at 1 year, and 2.1 and 1.3 at the last follow-up, respectively. The mean NDI score was 58.0 preoperatively, 19.4 postoperatively, 17.0 at 6 months, 16.1 at 1 year, and 16.2 at the last follow-up. Radiologic studies revealed a preserved range of motion in 33 of 35 patients. No ASD occurred and no reoperation was required. Conclusions Cervical disk arthroplasty with a keel-less prosthesis can be a safe and effective alternative to fusion for degenerative disk disease in selected patients, with a possible reduction of ASD. [ABSTRACT FROM AUTHOR]

Introduction: In this double-blinded randomized controlled trial, we compare the long-term clinicoradiological effects of anterior cervical discectomy and fusion with polyether ether ketone implant (ACDF with PEEK) versus artificial cervical disc (cervical disc arthroplasty [CDA]) in patients with single and bilevel cervical degenerative disc disease (CDDD). Aims: We aimed to compare the pain scores, cervical kinematics, and radiological outcomes in patients undergoing CDA and ACDF for single and bilevel CDDD over 5 years. Settings and Design: This study was carried out from 2010 to 2019 in the Neurosurgery Department of a Tertiary Care Hospital attached to a Medical College in India. Subjects and Methods: We enrolled 30 patients in each group. Clinical and radiological assessments were carried out for all patients over a period of 5 years. Statistical Analysis Used: Wilcoxon Signed-rank test, Mann-Whitney U-test, and Fischer's exact test were used for comparing the preoperative and follow-uP values. R software version 3.6.0 was used for statistical analysis. Results: A significant improvement in the cervical range of motion, sagittal range of motion (ROM), and functional spinal unit (FSU) was observed in the CDA group at final follow-up, while the PEEK group reported a significant decrease in the ROM and FSU and the difference between the two groups was also found to be statistically significant. Conclusions: When assessed over 5 years following surgery, we found CDA to be superior with respect to ROM, FSU, overall cervical alignment, and maintenance of disc height when compared to ACDF with PEEK implant. [ABSTRACT FROM AUTHOR]

Quantitative bone re-modelling theories suggest that bones adapt to mechanical loading conditions. Follow-up studies have shown that total disc replacement (TDR) modifies stress patterns in the bones, leading to heterotopic ossification (HO). Although there are a few studies on HO using finite element models (FEM), its effect on the adjacent levels and change in range of motion (ROM) have not been adequately investigated. This study interfaces the HO using bone re-modelling algorithm with a finite element solution and investigates the subsequent changes in segmental ROM. A FEM of the human cervical spine (C3–C7) was developed for this study, with material properties obtained from literature. The motion of the segments in the sagittal, frontal and transverse planes under combined loading conditions of 1 Nm moment and 73.6 N compression were validated against experimental corridors. The natural disc between the C5–C6 segment was replaced with the Bryan artificial cervical disc, and changes in sagittal ROM were compared before and after HO. The process of HO was simulated using a bone remodelling algorithm using strain energy density (SED) as the mechanical stimuli. Our study demonstrates the feasibility of using SED calculations from the flexion-extension loading conditions for prediction of HO after ADR. The current findings suggest that the nature of trabecular stresses, and the subsequent rate and location of HO formation could differ based on the geometric design and nature of constraint for different artificial discs. The Bryan disc significantly reduced ROM at the implanted level in flexion. However, in extension, ROM increased at the implanted level and decreased slightly at the adjacent levels. After HO, ROM drastically reduced at the implanted level in both extension and flexion, and showed a minor increase in the adjacent levels, indicating that biomechanical behavior of high-grade HO is similar to a fused segment, thereby reducing the intended and initial motion preservation. [ABSTRACT FROM AUTHOR]

Objective: To perform a systematic literature review on revision surgeries at the index level after cervical disc arthroplasty (CDA) failure. Methods: A systematic literature review was performed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Prospective studies on patients who required a secondary surgery after CDA failure were included for analysis. The minimum follow-up for these studies was 5 years. Results: Out of 864 studies in the original search group, a total of 20 studies were included. From a total of 4,087 patients, 161 patients required a reoperation at the index level. A total of 170 surgeries were performed, as some patients required multiple surgeries. The most common secondary procedures were anterior cervical discectomy and fusion (ACDF) (68%, N = 61) and posterior cervical fusion (15.5%, N= 14), followed by other reoperation (13.3%, N = 12). The associated outcomes for those who required a revision surgery were rarely mentioned in the included literature. Conclusion: The long-term revision rate at the index level of failed CDA surgery was 3.9%, with a minimum 5-year follow-up. ACDF was the most commonly performed procedure to salvage a failed CDA. Some patients who required a new surgery after CDA failure may require a more extensive salvage procedure and even subsequent surgeries. [ABSTRACT FROM AUTHOR]

Background: Traditional surgical treatment for symptomatic cervical degenerative disc disease is anterior cervical discectomy and fusion (ACDF), yet the increased risk of adjacent segment degeneration (ASD) requiring additional surgery exists and may result in limiting long-term surgical success when it occurs. Disc arthroplasty can preserve or restore physiologic range of motion (ROM), decreasing adjacent level stress and subsequent surgery. For patients with multilevel pathology requiring at least a 1-level fusion, interest is growing in anterior cervical hybrid (ACH) surgery as a partial motion-preserving procedure to decrease the adjacent level burden. This radiographic study compares postoperative superior adjacent segment motion between ACH and ACDF. Secondarily, total global motion, construct motion, inferior adjacent segment motion, and sagittal alignment parameters were compared., Methods: This is a single-center, multi-surgeon, retrospective cohort study of 2- and 3-level ACH and ACDF cases between 2013 and 2021. Degrees of motion were analyzed on flexion/extension views using Cobb angles to measure global (C2-C7) construct and adjacent segment lordosis. Neutral lateral X-rays were analyzed for alignment parameters, including global lordosis, cervical sagittal vertical axis (cSVA), and T1 slope (T1S). Differences were determined by independent t-test and Fisher's exact test., Results: Of 100 patients, 38% were 2-level cases (47% ACH, 53% ACDF) and 62% were 3-level cases: (52% ACH, 48% ACDF). Postoperatively, superior adjacent segment motion increased with ACDF and decreased with ACH (-1.3°±5.3° ACH, 1.6°±4.6° ACDF, P=0.005). Postoperatively, the ACH group had greater ROM across the construct (16.3°±8.7° ACH, 4.7°±3.3° ACDF, P<0.001) and total global ROM (38.0°±12.8° ACH, 28.0°±11.1° ACDF, P<0.001). ACH resulted in a significant reduction of motion loss across the construct (-10.0°±11.7° ACH, -18.1°±10.8° ACDF, P<0.001). Postoperative alignment restoration was similar between both cohorts (-2.61°±8.36° ACH, 0.04°±12.24° ACDF, P=0.21)., Conclusions: Compared to ACDF, hybrid constructs partially preserved motion across operative levels and had greater postoperative global ROM without increasing superior adjacent segment mobility or sacrificing alignment restoration. This supports the consideration of ACH in patients with multilevel degenerative cervical pathology requiring at least a 1-level fusion and suggests a propensity for long-term success by reducing the superior adjacent segment burden., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-23-135/coif). L.D.O. and R.T.R. received institutional research support from Medtronic and Innovasis. C.R.G. serves on an advisory board for Stryker/K2M, Medtronic, and Augmedics. C.R.G. reports royalties and consulting fees from Stryker/K2M and Medtronic; institutional educational research support from Medtronic; owns stock in Audmedics and NSite. E.J. reports consulting fees from Stryker, Medtronic, and Innovasis. C.M.H. reports personal fees from Medtronic, Globus Medical, Spineart, and Innovasis. The other authors have no conflicts of interest to declare., (2024 Journal of Spine Surgery. All rights reserved.)

BackgroundCervical total disk replacement (TDR) is intended to address pain and preserve motion between vertebral bodies in patients with symptomatic cervical disk disease. Two-year follow-up for the ProDisc-C (Synthes USA Products, LLC, West Chester, Pennsylvania) TDR clinical trial showed non-inferiority versus anterior cervical discectomy and fusion (ACDF), showing superiority in many clinical outcomes. We present the 4-year interim follow-up results.MethodsPatients were randomized (1:1) to ProDisc-C (PDC-R) or ACDF. Patients were assessed preoperatively, and postoperatively at 6 weeks and 3, 6, 12, 18, 24, 36, and 48 months. After the randomized portion, continued access (CA) patients also underwent ProDisc-C implantation, with follow-up visits up to 24 months. Evaluations included Neck Disability Index (NDI), Visual Analog Scale (VAS) for pain/satisfaction, and radiographic and physical/neurologic examinations.ResultsRandomized patients (103 PDC-R and 106 ACDF) and 136 CA patients were treated at 13 sites. VAS pain and NDI score improvements from baseline were significant for all patients (P < .0001) but did not differ among groups. VAS satisfaction was higher at all time points for PDC-R versus ACDF patients (P = .0499 at 48 months). The percentage of patients who responded yes to surgery again was 85.6% at 24 months and 88.9% at 48 months in the PDC-R group, 80.9% at 24 months and 81.0% at 48 months in the ACDF group, and 86.3% at 24 months in the CA group. Five PDC-R patients (48 months) and no CA patients (24 months) had index-level bridging bone. By 48 months, approximately 4-fold more ACDF patients required secondary surgery (3 of 103 PDC-R patients [2.9%] vs 12 of 106 ACDF patients [11.3%], P = .0292). Of these, 6 ACDF patients (5.6%) required procedures at adjacent levels. Three CA patients required secondary procedures (24 months).ConclusionsOur 4-year data support that ProDisc-C TDR and ACDF are viable surgical options for symptomatic cervical disk disease. Although ACDF patients may be at higher risk for additional surgical intervention, patients in both groups show good clinical results at longer-term follow-up.

Cervical angina is an often-overlooked etiology of noncardiac chest pain that may mimic true angina pectoris but is due to cervical spine disease. Diagnosis can be difficult, and treatment ranges from conservative therapy to surgical management. However, of patient’s refractory to conservative therapy, approximately ninety percent experience postoperative relief of angina symptoms. Here, we present a case report on cervical angina and performed a systematic review of the literature. A 34-year-old male with prior surgery for thoracic outlet syndrome presented with persistent anterior neck and chest pain as well as posterior left scapular and upper lateral arm pain. The pain was refractory to 12 months of conservative therapy. Cardiac workup was negative and cervical spine imaging revealed a C6–7 herniation with neuroforaminal stenosis. A systematic literature search was conducted in PubMed, Web of Science, and Cochrane databases from database inception to April 2020. Studies reporting cervical level, average symptom duration, location of pain, and postoperative pain improvement were included. The patient's atypical symptoms were completely resolved after C6–7 anterior cervical discectomy and arthroplasty. To our knowledge, this is the first study which reports on the use of arthroplasty in the treatment of cervical angina. The systematic review included 11 articles from 1989–2020 consisting of 1,186 total patients and 109 patients (age range, 36–84 years; 60.7% male) meeting inclusion criteria. Symptom duration range was 2 days to 90 months, with the most common location of pain being localized to the anterior chest wall (66.7% of patients). All patients (100%) had postoperative resolution of their pain symptoms. The most common herniation level was C6–7 (87.3% of patients). We conclude that a broad and multidisciplinary approach is necessary for the diagnosis and management of noncardiac chest pain. When cervical disease is identified as the underlying cause for the angina-like pain, conservative therapy should be sought. Refractory cases should be treated surgically depending on the cervical pathology. [ABSTRACT FROM AUTHOR]

Purpose: Cervical disc arthroplasty (CDA) has become an increasingly popular treatment for cervical degenerative disc disease. One potential complication is osteolysis. However, current literature on this topic appears limited. The purpose of this study is to elucidate the incidence, aetiology, consequence, and subsequent treatment of this complication. Methods: A systematic literature review was performed according to the PRISMA guidelines. Studies discussing the causes, incidence and management of osteolysis after a CA were included. Results: A total of nine studies were included. We divided these studies into two groups: (1) large case series in which an active radiological evaluation for osteolysis was performed (total = six studies), (2) case report studies, which discussed symptomatic cases of osteolysis (total = three). The incidence of asymptomatic osteolysis ranged from 8 to 64%; however, only one study reported an incidence of < 10% and when this case was excluded the incidence ranged from 44 to 64%. Severe asymptomatic bone loss (exposure of the implant) was found in less than 4% of patients. Bone loss from osteolysis appeared to occur early (< 1 year) after surgery and late (> 1 year) as well. Symptomatic patients with osteolysis often required revision surgery. These patients required removal of implant and conversion to fusion in the majority of the cases. Conclusions: Osteolysis after CDA is common; however, the majority of cases have only mild or asymptomatic presentations that do not require revision surgery. The timing of osteolysis varies significantly. This may be due to differences in the aetiology of osteolysis. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study is to examine the biomechanical alterations in the index and adjacent levels of the human cervical spine after cervical arthroplasty with Bryan, Prodisc C, or Prestige LP.Methods: A previously validated C2-T1 osteoligamentous finite element model was used to perform virtual C5-6 arthroplasty using three different FDA-approved artificial cervical discs. Motion-controlled moment loading protocol was used. Moment was varied until Bryan, Prodisc C, and Prestige LP models displayed the same total range of motion across C3-C7 as the intact spine model at 2 Nm of pure moment loading. Range of motion (ROM) and facet force (FF) were recorded at the index level. ROM, FF, and intradiscal pressure (IDP) were recorded at the adjacent levels.Results: Prodisc C and Prestige LP led to supraphysiologic ROM and FF at the index level while decreasing ROM and FF at the adjacent levels. In contrast, Bryan reduced ROM and FF at the index level. Bryan increased ROM and FF at the adjacent levels in flexion, but decreased ROM and FF in the adjacent levels in extension. Prodisc C decreased IDP at the adjacent levels. Bryan reduced IDP in extension only. Prestige LP increased adjacent-level IDP.Conclusions: The distinct designs and material compositions of the three artificial discs result in varying biomechanical alterations at the index and adjacent levels in the cervical spine after implantation. The findings confirm the design and material influence on the spine biomechanics, as well as the advantages and contraindications of cervical arthroplasty in general. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: We investigated whether outcomes after cervical total disc replacement (cTDR) are influenced by preoperative neck pain as the chief complaint. Methods: This was a retrospective study using data in our local spine surgery outcomes database, linked to EUROSPINE Spine Tango Registry. Patients completed questionnaires at baseline enquiring about the "chief complaint" [neck pain (NP), arm/shoulder pain (AP) or neurological deficits (ND)] and including the Core Outcome Measures Index (COMI); these were completed again at 24 months postoperatively, along with a rating of "global treatment outcome" (on a five-point scale, later dichotomized as "good" or "poor"). Differences in outcomes between the groups were examined using ANOVA. Multivariable regression analysis examined the effect of the chief pain location on 24-month outcomes, controlling for age, gender, comorbidity, baseline pain and COMI scores. Results: One hundred and fifty-nine consecutive patients were included, with a chief complaint of NP in 31%, AP in 38% and ND in 31%. The chief complaint groups did not differ in relation to their baseline COMI scores or their reductions in score from before surgery to 24 months after surgery (reduction: NP group, 4.4 ± 2.9 points; AP group, 4.7 ± 2.7; ND group, 4.3 ± 2.9; p = 0.78). Similarly, the percentage of patients reporting a "good global treatment outcome" at 24 months postoperatively did not differ between the groups (NP, 79%; AP, 77%; ND, 85%; p = 0.64). The findings were consistent when controlling for possible confounders in multiple regression. Conclusions: Having neck pain as opposed to arm pain or neurological deficits as preoperative chief complaint had no significant impact on clinical outcome after cTDR. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

In a standard surgical operating room, advanced imaging is projected on a separate monitor screen away from the surgical field of view. This setup requires surgeons to repeatedly shift their attention between the operative field and a screen. Such movement may result in a disruption of focus that can extend surgical time, cause physical strain, and lead to surgical errors. A potential solution to this inefficiency in the surgical workflow is to use a heads-up display (HUD) to mirror what is being displayed. A HUD projects preoperative or intraoperative imaging over the surgical field, allowing surgeons to visualize both as they perform surgery. We performed a single-level arthroplasty for a patient with right-sided disc herniation at C6-7. A HUD was used by the lead surgeon to continuously view intraoperative X-rays without needing to repeatedly turn away from the surgical field while placing Caspar pins into the C6 and C7 vertebral bodies, and malleating trials and the artificial disc into the disc space. Following surgery, the patient experienced resolution of his preoperative right arm and hand paresthesia and regained full strength. This case describes the novel use of the Moverio BT-35E Smart Glasses (Epson Inc, Suwa, Japan) HUD during a spine procedure. [ABSTRACT FROM AUTHOR]

Cervical arthroplasty is an accepted and widely performed surgical intervention with usually favorable outcomes. We report a rare case of a 37-year-old woman who presented with vertebral body osteolysis, 6 years after two-level cervical arthroplasty (C5–C6 and C6–C7). The patient showed no initial complications, but at year 6 she presented with neck and radicular arm pain. Diagnostic imaging revealed osteolysis of the vertebral body C6. The patient subsequently underwent removal of the two prostheses and C6 corpectomy, followed by bridging C5 to C7 and anterior fixation. During surgery, the mantle of the prostheses appeared broken, with the core expulsed anteriorly and embedded in granulomatous scar tissue. Pathologic evaluation of the samples showed partially proliferating fibroblasts, giant cell reaction, and textile particles. Postoperatively, clinical symptoms resolved with no residual deficits. Additional research should be performed to assess the long-term complications of this procedure that should be included in the patient informed consent materials. [ABSTRACT FROM AUTHOR]

To determine how center of rotation (COR) changes and what affects changes in COR after cervical arthroplasty. A systematic literature review of in vivo clinical studies comparing the location of the COR before and after cervical arthroplasty with different artificial prostheses was performed. Meta-analysis was performed using a fixed effects model where appropriate. A systematic review of the PubMed, EMBASE, and Cochrane Library databases was conducted. We initially identified 267 studies, of which 14 involved in vivo kinematics studies evaluating COR following cervical arthroplasty. We found that at the last follow-up, the COR location shifted anteriorly in patients from 4 studies including 85 segments, superiorly in patients from 4 studies including 98 segments, anterior-superiorly in patients from 4 studies including 290 segments, and anterior-inferiorly in patients from 1 study including 272 segments after cervical arthroplasty. The COR location showed no significant change in patients from 5 studies including 106 segments after cervical arthroplasty. Changes in COR showed a certain trend after cervical arthroplasty with different types of prostheses. Prosthesis design affects changes in COR after cervical arthroplasty. If a constrained or semiconstrained prosthesis is chosen (2-piece implant, ball-and-socket, or ball-in-trough design), the COR location tends to shift anteriorly and/or superiorly, whereas if a nonconstrained prosthesis is chosen (3-piece implant, mobile nucleus design), the COR tends to keep the same location as preoperation. In addition, the position of the prosthesis in the intervertebral space also can affect changes in COR after cervical arthroplasty. [ABSTRACT FROM AUTHOR]

Objective: Anterior cervical arthroplasty (ACA) is the gold standard surgery in severe or unresponsive cases of cervical disc herniation, uncarthrosis, and foraminal stenosis. The aim of this study is to establish the impact and outcome evaluations of managing the patients operated for cervical arthroplasty by the intersomatic porous alumina ceramic cervical cages (PACC). The authors describe their experience in the area to allow the comparison of effectiveness of ceramic cages versus other interbody fusion cages. Materials and Methods: Between April 2015 and September 2018, we operated 118 for ACA by using PACC. Among them, 52 were female and 66 were male, with an average age of 46.78 years. Results: The mean symptoms duration was 14.1 months. The most frequent level of the disorder was C5–C6 followed by C6–C7 level. Mean follow-up was 3.3 years. The Neck Disability Index (NDI) and the visual analog scale (VAS) were used to evaluate the patients status. No significant differences were observed between our results and literature data regarding operative time, duration of hospitalization, and NDI; however, we observed a shorter period and higher rate of bony fusion. Conclusion: The results from the present study corroborate that implementing of PACC is a good alternative treatment for the patient operated by ACA for cervical disc herniation or foraminal cervical stenosis.

Introduction: Cervical disc arthroplasty (CDA) was developed to decrease the rate of symptomatic adjacent-level disease while preserving motion in the cervical spine.Methods: The objectives of this paper are to provide criteria for proper patient selection as well as to present a comprehensive literature review of the current evidence for CDA, including randomized studies, the most recent meta-analysis findings, and long-term follow-up clinical trials as well.Results: Currently, there are several prospective randomized controlled studies of level I of evidence attesting to the safety and efficacy of CDA in the management of cervical spondylotic disease (CSD) for one- or two-level degenerative diseases. These as well as recent meta-analyses suggest that CDA is potentially similar or even superior to anterior cervical discectomy and fusion (ACDF) when considering several outcomes, including dysphagia and re-operation rate over medium-term follow-up. Less robust studies have also reported satisfactory clinical and radiological outcomes of CDA for hybrid procedures (ACDF combined with CDA), non-contiguous disease, and even for multilevel disease (more than 2 levels).Conclusions: Based on this evidence we conclude that CDA is a safe and effective alternative to ACDF in properly selected patients for one- or two-level diseases. Defining superiority of specific implants and detailing optimal surgical indications will require further well-designed long-term studies. [ABSTRACT FROM AUTHOR]

Objective To present a long-term clinical and radiographic comparison between the Prestige LP cervical disc replacement and the Zero-P spacer cervical disc fusion in the treatment of patients with symptomatic 2-level cervical degenerative disease. Methods In total, 36 patients in the anterior cervical discectomy and fusion (ACDF) group and 24 patients in the cervical disc arthroplasty (CDA) group were analyzed before surgery and at 1 week and 3, 6, 12, 24, and 60 months after surgery. Clinical assessments included the Japanese Orthopaedic Association score, visual analog scale, and Neck Disability Index scores. Radiographic assessments included cervical lordosis, range of motion (ROM) of the total cervical spine, functional spinal unit (FSU), and superior and inferior adjacent segments. Complications including heterotopic ossification and adjacent-segment degeneration (ASD) at 5-year follow-up were collected as well. Results Mean follow-up period was 65.6 months. Both the ACDF and CDA groups showed significant clinical improvements in terms of Japanese Orthopaedic Association score, visual analog scale, and Neck Disability Index (P < 0.05), but there was no significant difference between groups at the last follow-up period. A significant increase of cervical lordosis was observed in the CDA group after surgery whereas a significant difference was not observed between groups. ROM of the total cervical spine and FSU were maintained during the follow-up, and a significant decrease was observed in the ACDF group after surgery (P < 0.05). The ROM of the superior adjacent segment did not show any difference whereas the ROM of the inferior adjacent segment in the ACDF group presented a significant increase at 6 months and 1 year after surgery and a significant decrease at the last follow-up period. A total of 8 (33.3%) patients in the CDA group had an occurrence of heterotopic ossification. ASD was observed in 2 (8.3%) patients who underwent CDA surgery and 8 (22.2%) patients who underwent ACDF surgery. Conclusions The use of the Prestige-LP and ZERO-P Spacer implantations is safe and effective. At 5 years after surgery, CDA with Prestige-LP is superior in terms of ROM of the total cervical spine, FSU, and inferior adjacent segment. It also has a relatively low occurrence rate of ASD. This procedure may be a suitable choice for the treatment of contiguous 2-level CDDD. [ABSTRACT FROM AUTHOR]

Objective: Anterior cervical arthroplasty (ACA) is the gold standard surgery in severe or unresponsive cases of cervical disc herniation, uncarthrosis, and foraminal stenosis. The aim of this study is to establish the impact and outcome evaluations of managing the patients operated for cervical arthroplasty by the intersomatic porous alumina ceramic cervical cages (PACC). The authors describe their experience in the area to allow the comparison of effectiveness of ceramic cages versus other interbody fusion cages. Materials and Methods: Between April 2015 and September 2018, we operated 118 for ACA by using PACC. Among them, 52 were female and 66 were male, with an average age of 46.78 years. Results: The mean symptoms duration was 14.1 months. The most frequent level of the disorder was C5–C6 followed by C6–C7 level. Mean follow-up was 3.3 years. The Neck Disability Index (NDI) and the visual analog scale (VAS) were used to evaluate the patients status. No significant differences were observed between our results and literature data regarding operative time, duration of hospitalization, and NDI; however, we observed a shorter period and higher rate of bony fusion. Conclusion: The results from the present study corroborate that implementing of PACC is a good alternative treatment for the patient operated by ACA for cervical disc herniation or foraminal cervical stenosis. [ABSTRACT FROM AUTHOR]