Cervical Total Disc Replacement Research Articles

Five-year Follow-up of a Prospective Food and Drug Administration Investigational Device Exemption Trial Evaluating a PEEK-on-Ceramic Cervical Disc Replacement.

Prospective trial comparing the investigation group to propensity matched historic control group. To evaluate 5-year results of single-level PEEK-on-ceramic cervical total disc replacement (TDR) compared to a propensity matched anterior cervical discectomy and fusion (ACDF) control group. Cervical TDR has gained acceptance as treatment for symptomatic disc degeneration. The design and materials used in these devices continue to evolve. Data were collected in the Food and Drug Administration Investigational Device Exemption trial for the PEEK-on-ceramic Simplify(®) Cervical Artificial Disc (n=150) with comparison to a propensity matched ACDF control group (n=117). All patients were treated for single-level cervical disc degeneration with radiculopathy and/or myelopathy. Clinical outcome was based on composite clinical success (CCS), Neck Disability Index (NDI), visual analog scales (VAS) assessing pain, re-operations, and satisfaction. Radiographic measures included segmental range of motion (ROM), disc space height, and heterotopic ossification (HO). Evaluations were performed pre-operatively and post-operatively within 2 and 6 weeks, and 3, 6, 12 months, and annually thereafter. At 5-year follow-up, CCS was significantly greater with TDR than ACDF (91.1% vs. 74.6%; P<0.01). In the TDR group, the mean NDI score was 63.3 pre-operatively, reduced significantly to 23.1 at 6 weeks and remained below 20 throughout 5-year follow-up. In the ACDF group, the mean pre-operative NDI score was 62.4, decreasing to 33.7 at 6 weeks, and ranged from 25.9 to 21.5 throughout follow-up. Mean NDI scores were significantly lower in TDR group at all post-operative points (P<0.05). Mean TDR ROM was 7.3o pre-operatively and 10.1o at 5 years. Bridging HO occurred in 9%. With TDR, there were 6 re-operations (4.0%) vs. 11 (9.4%) with ACDF (P>0.40). PEEK-on-ceramic TDR produced significantly improved outcomes maintained throughout 5-year follow-up, were similar or superior to ACDF, supporting TDR in appropriately selected patients.

P213. Strategies for addressing a series of failed cervical total disc replacements

P213. Strategies for addressing a series of failed cervical total disc replacements

Treatment of failed cervical total disc replacements in a series of 53 cases and description of a management strategy.

To describe modes of failure of cervical TDR, their related treatment strategies, and to describe a management strategy for the treatment of failed cervical TDR. This retrospective study was based on a consecutive series of 53 cervical TDR patients who underwent removal or revision surgery. Chart review was conducted to collect general descriptive data, reasons for TDR removal/revision, duration from index implantation to re-operation, and the subsequent procedure performed. Among 53 patients, 36 underwent TDR removal and fusion, 16 underwent TDR removal and replacement with another TDR, and one patient's TDR was revised by repositioning. The mean duration from index surgery to removal/revision was 40.1months (range: 3days-222months). In all cases, removal/revision surgery was completed without complication. The most common reason for removal was severe osteolysis, often involving C. acnes infection, and was primarily associated with one implant type. TDR removal and fusion were performed for subsidence, device migration, treatment of symptoms arising from posterior anatomy (facet joints, etc.), approach-related complications and pain. TDR replacement was feasible for hypermobility, metal allergy, implant locked in kyphosis, and oversized implant use. In one case of TDR malpositioning, the device was successfully revised into appropriate position. After cervical TDR failure, replacing a TDR with another implant can be feasible. Reasons for revision or removal after cervical TDR surgery include biomechanical failure, implant migration, surgeon or technical error, or biological reasons. The type of failure can help the surgeon create a strategy to address these complications.

The Scientific Evidence for Lumbar Total Disk Replacement Surgery

Abstract Lumbar total disk replacement (TDR) has been in use since the 1980s, yet its adoption has not paralleled that of hip or knee arthroplasty or cervical TDR, which was introduced years after lumbar arthroplasty. If the lack of adoption is related to concerns about the safety and/or effectiveness of these implants, these issues have been extensively addressed in the literature. This narrative review aims to concisely report on the evidence published in the peer-reviewed literature related to lumbar TDR. Literature was identified from online databases such as PubMed, Scopus, and ScienceDirect, supplemented by the authors’ institution’s comprehensive database of TDR articles. By the end of 2023, there were at least 816 articles published on lumbar TDR covering all aspects of this technology, including biomechanics, clinical outcome, radiographic outcome, safety as assessed by re-operations and complications, and the cost related to this treatment intervention. Consistently, the evidence indicates that TDR yields outcomes similar or superior to fusion for treating painful disk degeneration unresponsive to non-operative care in appropriately selected patients.

Removals and Revisions of Cervical Total Disc Replacement Devices in a Consecutive Series of 1626 Patients Beginning With the First Case Experience in 2003.

Retrospective cohort study. The purpose of this study was to investigate the rate of cervical total disc replacement (TDR) device removal or revision. Cervical TDR has gained acceptance as an alternative to anterior cervical discectomy and fusion in appropriately selected patients. There have been concerns over device safety, one measure of which is subsequent surgery related to device problems. A consecutive series of 1626 patients undergoing cervical TDR from 2003 to June 2021 were included, consisting of TDRs up to 3 levels and hybrids (TDR and fusion). TDR removal or revision surgeries and reasons for these surgeries, procedures performed, and duration from index procedure were recorded. Data were analyzed to determine the removal/revision rate and factors possibly related to these events. There were 24 removals/revisions (1.48%) in the 1626 patients. Removal was performed in 23 cases (1.41%) and revision in 1 (0.06%). Among removal cases, anterior cervical discectomy and fusion was performed in 18 and TDR was replaced with another TDR in 5. Removals with fusion included 5 cases of osteolysis with/without Cutibacterium acnes , 4 device displacement/migration, 4 posterior spinal pathology, and one for each of the following: metal allergy, approach-related complications, malpositioning, subsidence, and hypermobility. The revision involved TDR repositioning 3 days after index surgery. There were 66 patients for whom a minimum of 10-year follow-up was confirmed, and none had removal/revision surgery 10 or more years after index surgery. There was no relationship between the occurrence of removal/revision and age, sex, body mass index, or physician experience (learning curve). The removal/revision rate was significantly higher in FDA trials versus postapproval (4.1% vs . 1.3%, P < 0.05). In this large consecutive series of patients, 1.48% of cervical TDRs were removed/revised. The low rate of removals/revisions over a long period of time provides support for the devices' safety. Level IV.

Heterotopic ossification, osteolysis and implant failure following cervical total disc replacement with the M6-C™ artificial disc

IntroductionA 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.MethodsWe 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.ResultsIn 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).ConclusionWe 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.

Influence of cervical total disc replacement on motion in the target and adjacent segments

Background ContextThe motion limitation after cervical discectomy and fusion alters the spine´s kinematics. Unphysiological strains may be the result and possible explanation for adjacent segment degeneration. Alterations to cervical kinematics due to cervical total disc replacement (TDR), especially two-level, are still underinvestigated. PurposeTo investigate cervical motion including coupled motions after one-level and two-level TDR in the treated and also the adjacent segments. Study DesignAn in-vitro study using pure moment loading of human donor spines. MethodsSeven fresh frozen human cervical spine specimens (C4-T1, median age 46 with range 19-60 years, four female) were included in this study. Specimens were tested in the intact condition first, followed by one-level TDR at C5-6 which was subsequently extended one level further caudal (C5-7). Each specimen was quasistatically loaded with pure moments up to 1.5 Nm in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. During the tests three dimensional motion tracking was performed for each vertebral body individually. From that the primary and coupled ROM of each spinal level during the third full cycle of motion were evaluated. Non-parametric statistical analysis was performed using a Friedman-test and post-hoc correction with Dunn-Bonferroni-tests (p < 0.05). Ethics approval was obtained in advance. ResultsIn FE, one-level TDR (C5-6) moderately increased primary FE in all four segments, but only significantly at the cranial adjacent level C4-5. Additional TDR at C6-7 further increased the ROM at the target segment without much influence on the other levels. Increasing implant height at C6-7 partially counteracted the increased FE. Coupled motions were minimal in all test conditions at all levels.In LB, coupled AR was observed in all test conditions at all levels. One-level TDR decreased primary LB at the target segment C5-6 significantly, without much influence on the other levels. Extending TDR to C6-7 decreased ROM in the target segment but without gaining statistical significance. Increasing implant height at C6-7 further decreased primary LB at the target segment, still without significance. Notably, coupled AR was significantly decreased at the cranial adjacent segment C4-5 compared to the intact condition.In AR, coupled LB was observed in all test conditions at the levels C4-5, C5-6 and C6-7, while the transition level to the thoracic spine C7-T1 showed only little coupled LB. Both one-level and two-level TDR showed little influence on primary AR or coupled motions at any level. Only after increasing implant height at C6-7 was the motion of the caudally adjacent level C7-T1 significantly altered. ConclusionEvaluating primary FE, LB and AR together with the associated coupled motions revealed widespread influence of cervical TDR not only on the motion of the treated level but also at the adjacent segments. The influence of two-level TDR is more widespread and involves more levels than one-level TDR. Clinical SignificanceThe prevention of unphysiological strains due to altered kinematics after cervical fusion, which could possibly explain adjacent segment degeneration, were a driving factor in the development of TDR. These experimental findings suggest cervical TDR influences the whole cervical spine, not only the treated segment. The effect becomes more extensive, involving more levels and motion directions, after two-level than after one-level TDR.

Adjacent segment degeneration after single- and double-level cervical total disc replacement: a cohort with an over 12-year follow-up.

To characterize the change of adjacent segment degeneration (ASD) after cervical total disc replacement (CTDR) with more than 12-year follow-up, and identify the risk factors for ASD. This process included 75 patients underwent CTDR from February 2004 to December 2012, with the follow-up of 151.9 ± 36.0 (m). The artificial disc included ProDisc-C, Prestige-LP and Mobi-C. ASD was followed up at 1week, 6months, 1year, 2years, 5years, 10years after CTDR and at the endpoint of June 2022. The radiographic measurements were cervical mobility, intervertebral disc height (IDH), cervical lordosis and balance status. The complications were implant migration, subsidence and heterotopic ossification (HO). Cervical mobility in adjacent segments, IDH and lordosis showed no statistical differences between ASD and NASD group. Balance status, subsidence and migration showed no relationship with ASD. Postoperative ASD increased at 6m and especially between 6m to 2y. There was no difference between the incidence of upper ASD and lower ASD all the time and few ASD-related reoperation. The majority of adjacent segments were C4/5 (33.6%) and C6/7 (34.2%), and ASD of C5/6 had the highest incidence (61.5%). Cox regression showed ASD was not related to the types of prosthesis or operated numbers. Generalized estimating equations (GEE) analysis showed severe HO had a higher (2.68 times) probability to suffer from ASD. After over 12-year follow-up of CTDR, the occurrence of ASD and HO had temporal synchronization. ASD was not merely a natural progression but with the pathological process such as HO.

Cervical Total Disc Replacement in Athletes: A Systematic Review.

Systematic review. To perform a systematic review to describe clinical characteristics, outcomes, and return to play after cervical total disc replacement (cTDR) in athletes. The role of cTDR in treating athletes with symptomatic cervical degenerative disc disease is undefined. A systematic search using MEDLINE through PubMed, EMBASE, and the Cochrane Library was conducted to identify all relevant literature. Data regarding study type, country in which the study was conducted, sample size, mean age, sex, type of sport, level of patient participation in sports, surgical indication, levels operated, type of implant, duration of follow-up, reoperations, surgical complications, extent of postoperative return to sports (RTSs), time to RTSs, and outcome notes were extracted from the included studies and analyzed. Seven studies, including 4 case series and 3 case reports, and a total of 57 cTDR cases, were included. There was significant heterogeneity among the cTDR cases in terms of chosen sport and level of participation. Prestige LP was utilized in 51 out of 57 (89.5%) cases and 53 out of 57 (93%) cases were single-level. No reoperations were noted at a mean follow-up of 51.6 months. All patients returned to sports postoperatively. Return to training and competition occurred at a mean of 10.1 weeks and 30.7 weeks postoperatively, respectively. The available evidence regarding cTDR in athletes indicates that these patients RTSs at high rates, with return to training occurring around 10 weeks and return to competition occurring around 30 weeks. Clinical outcomes in these patients are like those reported for the general population. Low-level evidence, small numbers of cases, heterogeneity in chosen sport and participation level, and predominance of a single implant type limit the conclusions that can be drawn from the current literature on this patient population.

The move-C cervical artificial disc can restore intact range of motion and 3-D kinematics

BACKGROUND CONTEXTIn contrast to cervical discectomy and fusion, total disc replacement (TDR) aims at preserving the motion at the treated vertebral level. Spinal motion is commonly evaluated with the range of motion (ROM). However, more qualitative information about cervical kinematics before and after TDR is still lacking. PURPOSEThe aim of this in vitro study was to investigate the influence of cervical TDR on ROM, instantaneous centers of rotation (ICR) and three-dimensional helical axes. STUDY DESIGNAn in vitro study with human spine specimens under pure moment loading was conducted to evaluate the kinematics of the intact cervical spine and compare it to cervical TDR. METHODSSix fresh frozen human cervical specimens (C4–5, median age 28 years, range 19–47 years, two female and four male) were biomechanically characterized in the intact state and after implantation of a cervical disc prosthesis (MOVE-C, NGMedical, Germany). To mimic in vivo conditions regarding temperature and humidity, water steam was used to create a warm and humid test environment with 37°C. Each specimen was quasistatically loaded with pure moments up to ±2.5 Nm in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. For each third cycle of motion the ROM was evaluated and an established method was used to determine the helical axis and COR and to project them into three planar X-rays. Statistical analysis was conducted using a Friedman-test and post hoc correction with Dunn-Bonferroni-tests (p<.05). RESULTSAfter TDR, total ROM was increased in FE from 19.1° to 20.1°, decreased in LB from 14.6° to 12.6° and decreased in AR from 17.7° to 15.5°. No statistical differences between the primary ROM in the intact condition and ROM after TDR were detected. Coupled rotation between LB and AR were also maintained. The position and orientation of the helical axes after cervical TDR was in good agreement with the results of the intact specimens in all three motion directions. The ICR in FE and AR before and after TDR closely matched, while in LB the ICR after TDR were more caudal. The intact in vitro kinematics we found also resembled in vivo results of healthy individuals. CONCLUSIONThe results of this in vitro study highlight the potential of artificial cervical disc implants to replicate the quantity as well as the quality of motion of the intact cervical spine. CLINICAL SIGNIFICANCEPhysiological motion preservation was a driving factor in the development of cervical TDR. Our results demonstrate the potential of cervical TDR to replicate in vivo kinematics in all three motion directions.

P70. Incidence of implant removal or revision surgery after cervical total disc replacement in a consecutive series of 1,615 patients beginning with the first case experience in 2003

P70. Incidence of implant removal or revision surgery after cervical total disc replacement in a consecutive series of 1,615 patients beginning with the first case experience in 2003

Finite element analysis of optimized novel additively manufactured non-articulating prostheses for cervical total disc replacement.

Ball-and-socket designs of cervical total disc replacement (TDR) have been popular in recent years despite the disadvantages of polyethylene wear, heterotrophic ossification, increased facet contact force, and implant subsidence. In this study, a non-articulating, additively manufactured hybrid TDR with an ultra-high molecular weight polyethylene core and polycarbonate urethane (PCU) fiber jacket, was designed to mimic the motion of normal discs. A finite element (FE) study was conducted to optimize the lattice structure and assess the biomechanical performance of this new generation TDR with an intact disc and a commercial ball-and-socket Baguera®C TDR (Spineart SA, Geneva, Switzerland) on an intact C5-6 cervical spinal model. The lattice structure of the PCU fiber was constructed using the Tesseract or the Cross structures from the IntraLattice model in the Rhino software (McNeel North America, Seattle, WA) to create the hybrid I and hybrid II groups, respectively. The circumferential area of the PCU fiber was divided into three regions (anterior, lateral and posterior), and the cellular structures were adjusted. Optimal cellular distributions and structures were A2L5P2 in the hybrid I and A2L7P3 in the hybrid II groups. All but one of the maximum von Mises stresses were within the yield strength of the PCU material. The range of motions, facet joint stress, C6 vertebral superior endplate stress and path of instantaneous center of rotation of the hybrid I and II groups were closer to those of the intact group than those of the Baguera®C group under 100N follower load and pure moment of 1.5 Nm in four different planar motions. Restoration of normal cervical spinal kinematics and prevention of implant subsidence could be observed from the FE analysis results. Superior stress distribution in the PCU fiber and core in the hybrid II group revealed that the Cross lattice structure of a PCU fiber jacket could be a choice for a next-generation TDR. This promising outcome suggests the feasibility of implanting an additively manufactured multi-material artificial disc that allows for better physiological motion than the current ball-and-socket design.

Biomimetic Design of 3D Fibrous Mesh Reinforced Hydrogel Replicating the Form and Function of the Intervertebral Disc

A Biomimetic Design of the Artificial Intervertebral Disc In article number 2200254 Wei Lei, Mingjie Liu, Yang Zhang, and co-workers fabricate biomimetic prototype of artificial intervertebral disc with nature-mimicking mechanics and structure. The design possesses an angle-ply fiber scaffold with multi-scale structural hierarchy, which exhibits osmotic behaviors, non-linear viscoelasticity and durability, enduring it with a great potential for total cervical disc replacement in future.

Biomimetic Design of 3D Fibrous Mesh Reinforced Hydrogel Replicating the Form and Function of the Intervertebral Disc

While cervical total artificial disc replacement potentially preserves motion of the natural intervertebral disc (IVD), problems also arise involving alterations of the spinal biomechanics. A major challenge lies in restoring mechanics of the natural IVD with appropriate kinematics and biomimetic configuration. A biomimetic artificial IVD model is designed and fabricated using a 3D braided fibrous scaffold and a self‐healable hydrogel matrix. The artificial IVD is characterized by 3D four‐directional fibrous structure resembling natural annulus fibrosus and self‐healable hydrogel‐mimicking natural nucleus pulposus. In the compression tests, the artificial IVD exhibits reasonable mechanical behaviors and desired viscoelastic behaviors similar to the natural IVD. After fatigue loading of 5 million cycles, the artificial IVDs become stiffer, whereas the mechanical values remain within the reasonable range. Finite‐element analysis of the artificial IVD from mesoscale and macroscale analysis indicates the coherent load transfer through both the interconnections within the fiber mesh and the fiber–matrix interface, and the entire IVD shows a stress profilometry similar to natural IVD. In conclusion, a biomimetic prototype of artificial IVD with nature‐mimicking mechanics and structure is fabricated. The presence of interwoven fibrous mesh, hydrogel confinement, and proper interfacial adhesion is all essential for scalable production of the IVD.

Long-term follow-up of wear-related osteolysis in cervical total disc replacement with the M6-C™ artificial cervical disc

Long-term follow-up of wear-related osteolysis in cervical total disc replacement with the M6-C™ artificial cervical disc

A Retrospective Comparative Study of Long-Term Outcomes Following Cervical Total Disc Replacement Versus Anterior Cervical Discectomy and Fusion.

Introduction The traditional treatment for patients with radiculopathy and myelopathy caused by degenerative disc disease was anterior cervical discectomy and fusion (ACDF). However, a documented complication of ACDF is adjacent segment degeneration (ASD). An alternative that was developed was total disc replacement (TDR). The aim of this study was to determine and compare the short- and medium-to-long-term outcomes after a TDR or ACDF. Methods A retrospective review of 154 patients who had single and two-level ACDFs and 90 TDRs performed by a single surgeon between 2011 and 2017 was conducted. Parameters for comparisons include both radiological evaluation and patient-reported outcome measures (PROMS) at six weeks, one year, and two years postoperatively. The Neck Disability Index (NDI) and the visual analogue scale (VAS) for neck and arm pain are used to evaluate pain, function, patient satisfaction, and overall clinical success. Results TDR and ACDF showed significant improvement in NDI and VAS when compared to pre- and post-operatively at both six weeks (p<0.05 & P=0.032, respectively) and two years (p<0.05 & 0=0.026, respectively). TDR vs. ACDF showed no significant difference (p<0.05). VAS scores after ACDF showed improvement from 13.41 to 3.94 at two years (p<0.001). TDR showed similar scores of 12.5 to 3.55 (p<0.001). The radiological fusion rate at 12 or 24 months showed no significant difference between the two groups. There were two cases that required re-operation after ACDF (1.2%), and two that required TDR (2.2%). Conclusion Both TDR and ACDF lead to clinically significant improvements in pain and function scores. We did not find a statistically significant difference in NDI and VAS in the neck and arm. The results are in agreement with others' assessments of these two treatment modalities. Our conclusions supplement the literature about these operative options for degenerative disc disease of the cervical spine and are a useful addition to the armamentarium in the assessment of patients with degenerative pathology of the c-spine.

Ceramics in total disc replacements: A scoping review.

Ceramics are used in Total Disc Replacements (1) in articulating surfaces for their wear resistance and biocompatibility and (2) on endplates to promote osseointegration. They furthermore exhibit MRI and CT compatibility. These properties address main challenges associated with non-ceramic Total Disc Replacements i.e. wear, migration and postoperative imaging. While brittleness of ceramics caused fear of fracture in the past, improvements of ceramic materials were made and considerable clinical experience with ceramic Total Disc Replacements was gained. This review aims to assess the evidence on the use of ceramics in Total Disc Replacements and compare safety and effectiveness of ceramic Total Disc Replacements to spinal fusion and Total Disc Replacements in general. We conducted a scoping review on the use of ceramics in Total Disc Replacements using Scopus, Web of Science and PubMed. The review includes 36 clinical, ex vivo and nonhuman in vivo, tribological and mechanical studies and case reports. Ceramics are used in cervical Total Disc Replacements, with safety and efficacy confirmed in clinical studies, with up to 10 and 3.3years follow-up, for articulation and osseointegration applications, respectively. Clinical evidence shows that ceramic Total Disc Replacements (alike non-ceramic ones) restore segmental motion and result in non-inferior and possibly superior outcomes to spinal fusion. In vivo studies show osseointegration comparable to non-ceramic devices. Tribological studies suggest appropriate wear properties. We found no indications of systematic problems with the use of ceramics in Total Disc Replacements. Ceramics are suitable materials for Total Disc Replacements.

Early Experiences of One-Level Total Disc Replacement (Prestige LP) in Japan: A Comparison of Short-Term Outcomes with Anterior Cervical Discectomy with Fusion.

In Japan, cervical total disc replacement (TDR) was approved in 2017. However, because of its short history, no comparative study between cervical TDR and anterior cervical discectomy with fusion (ACDF) has been conducted in the country. Therefore, we examined and compared the surgical outcomes of TDR and ACDF for one-level cervical degenerative diseases. In total, 50 patients who had received anterior surgeries for one-level cervical degenerative diseases were investigated. Among them, 25 underwent TDR (Prestige LP; Medtronic), whereas the other 25 patients underwent ACDF. ACDF samples were selected from cases conducted before the approval of TDR (-2017.9) and were retrospectively judged to be indicated for TDR. Before and at 1 year after surgery, clinical and radiological outcomes were evaluated. No significant differences in terms of patient demographics between the two groups were observed. A longer operative time was observed in the TDR group than in the ACDF group. Postoperatively, no differences in the Japanese Orthopaedic Association score for cervical myelopathy (C-JOA) score, neck pain visual analog scale, C2-7 angle, and C2-7 range of motion (ROM) were determined. TDR tended to show better neck disability index (NDI) scores postoperatively when compared with ACDF. The local angle at operative level was larger in ACDF. In TDR, the local ROMs were maintained postoperatively; however, in ACDF, the local ROM at the operative level was decreased, and the local ROMs at adjacent levels were increased postoperatively. In the TDR group, although heterotopic ossification was observed in 11 patients (44.0%), and anterior bone loss was identified in 14 patients (56.0%), these issues did not affect surgical outcomes. Conclusively, no differences in terms of C-JOA score and neck pain between patients treated through TDR and ACDF were observed. However, a trend of better NDI scores was identified with TDR. While TDR maintained postoperative ROMs, ACDF showed an increase in the local ROMs at adjacent levels.

Cervical Total Disc Replacement and Anterior Cervical Discectomy and Fusion: Comparison of 30-Day Population Comorbidities and Perioperative Complications Using 6 Years of American College of Surgeons National Surgical Quality Improvement Program Participant Use File Data

American College of Surgeons National Surgical Quality Improvement Program Participant Use File data from 2014 through 2019 were used to compare 1- and 2-level anterior cervical discectomy and fusion (ACDF) and cervical total disc replacement (cTDR) with respect to: patient demographics, comorbidities, adverse events, and 30-day morbidity rates. One- and 2-level ACDF and cTDR patients were identified by current procedural terminology codes. Demographics, comorbidities, and adverse events were summarized. Unmatched cohorts were compared using Wilcoxon Rank Sum test for continuous variables, Pearson χ2 test for categorical variables, and 30-day morbidity using inverse probability of treatment weighted log-binomial regression. American College of Surgeons National Surgical Quality Improvement Program 2014 through 2019 Participant Use File datasets represent 4,862,497 unique patients, identifying 13,347 1-level, 6933 2-level ACDF, 3114 1-level, and 862 2-level cTDR patient cohorts. Statistically significant differences between cohorts are extensive: age, sex, race, admission status, patient origin, discharge disposition, emergent surgery, surgical specialty, American Society of Anesthesiologists classification, wound class, operative time, hospital LOS, BMI, functional status, smoking, diabetes, dyspnea, chronic obstructive pulmonary disease, congestive heart failure, hypertension, renal failure, dialysis, cancer, steroid use, anemia, bleeding disorders, systemic sepsis, and number of concurrent comorbid conditions. Inverse probability of treatment weighted log-binomial models, demonstrated increased risk of deep venous thrombosis/thrombophlebitis, pulmonary embolism, deep incisional surgical site infection, pneumonia, and unplanned return to operating room associated with ACDF while increased risk of cerebral vascular accident/stroke with neurological deficit and myocardial infarction associated with cTDR. The composite complications outcome favors cTDR over ACDF for 30-day morbidity. No mortalities occurred within the cTDR cohort. Adjusting for demographics and comorbidities; ACDF has a higher average risk of adverse event. When ACDF and cTDR are equipoise, consideration for cTDR may be indicated in populations with higher rates of comorbid conditions.

Prospective, multicenter study of 2-level cervical arthroplasty with a PEEK-on-ceramic artificial disc.

The purpose of this study was to evaluate the safety and efficacy of a PEEK-on-ceramic cervical total disc replacement (cTDR) device for the treatment of 2-level cervical disc disease with radiculopathy and/or myelopathy. The study was a prospective, nonrandomized, historically controlled FDA investigational device exemption trial evaluating the Simplify Cervical Artificial Disc for use at 2 levels. The anterior cervical discectomy and fusion (ACDF) control group was derived from a propensity score-matched (using subclassification) cohort of patients who participated in an earlier prospective trial in which similar indications were used. The follow-up duration was 24 months. The primary outcome was a 4-point composite success classification. Other validated clinical and radiographic assessments were also evaluated. The investigational group (n = 182) was compared with patients who underwent ACDF (n = 170) in a historical control group using propensity score analysis. The overall composite success rate was statistically significantly greater in the cTDR group compared with the ACDF group (86.7% vs 77.1%; p < 0.05). The mean Neck Disability Index scores improved significantly in both groups, with cTDR significantly lower at some follow-up points. At the 24-month follow-up, a minimum 15-point improvement in Neck Disability Index scores was achieved in 92.9% of the cTDR group and 83.5% of the ACDF group (p > 0.05). In both groups, neck and arm pain scores improved significantly (p < 0.05) by 6 weeks and improvement was maintained throughout follow-up. Segmental range of motion was maintained at both treated segments in the cTDR group. MRI performed in the cTDR group at 24 months postoperatively found minimal changes in facet joint degeneration. The rate of subsequent surgical intervention was 2.2% in the cTDR group and 8.8% in the ACDF group. This study adds to the growing body of literature supporting cTDR for 2-level cervical disc disease with radiculopathy or myelopathy. cTDR showed a superior overall success rate compared to ACDF, while maintaining motion. These results support that the Simplify disc is a viable alternative to ACDF in appropriately selected patients with 2-level cervical spondylosis.