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Anterior cervical discectomy and fusion (ACDF) has been considered the standard treatment for degenerative cervical disc disease; however, recent trials have shown comparable outcomes with cervical disc arthroplasty (CDA). This study aimed to observe disparities in treatment paradigms of single-level cervical disc diseases and compare inpatient outcomes between procedures.A retrospective cohort of patients treated for single-level cervical disc herniation or degeneration without myelopathy was queried from the Nationwide Inpatient Sample spanning 2012-2015. Multivariate logistic regression was performed to assess the effects of demographics, temporality of admission, and hospital characteristics on odds of receiving CDA versus ACDF. Propensity-score matching was performed to compare cost, length of stay (LOS), non-home discharge, and inpatient complications.In total, 1028 CDAs and 44,374 ACDFs were performed for single-level cervical disc disease during 2012-2015. Matched comparison showed that while non-home discharges were not different between CDA and ACDF (P = 0.248), patients who received CDA had a 0.19-day shorter LOS (P0.001) and $4694 greater total cost (P0.001). There were no statistically significant differences in inpatient complication rates. Multivariate analysis showed that patients in the 26th-50th percentile, 51st-75th percentile, and 76th-100th percentile of median household income had greater odds of CDA compared with patients in the 0-25th percentile (odds ratio [OR] 1.35, P = 0.003; OR 1.31, P = 0.013; OR 1.34, P = 0.011, respectively). Patients with private insurance had greater odds of receiving CDA compared with patients on Medicare (OR 1.91, P0.001).CDA was associated with shorter LOS but greater costs compared with ACDF. Patients with greater median income and private insurance were more likely to receive CDA.

Low back pain is the leading cause of work absences and years lived with disability, and it is often associated with degenerative disc disease. In recent years, biological treatment approaches such as the use of growth factors, cell injections, annulus fibrosus (AF) repair, nucleus pulposus replacement, and tissue-engineered discs have been explored as means for preventing or reversing degenerative disc disease. Both animal and clinical studies have shown promising results for cell-based therapy on the grounds of its regenerative potential. Clinical data also indicate that stem cell injection is safe when appropriately performed, albeit its long-term safety and efficacy are yet to be explored. Numerous challenges also remain to be overcome, such as isolating, differentiating, and preconditioning the disc cells, as well as managing the nutrient-deficient and oxygen-deficient micromilieu of the intervertebral disc (IVD). AF repair methods including devices used in clinical trials have shown success in decreasing reherniation rates and improving overall clinical outcomes. In addition, recent studies that combined AF repair and nucleus pulposus replacement have shown improved biomechanical stability in IVDs after the combined treatment. Tissue-engineered IVDs for total disc replacement are still being developed, and future studies are necessary to overcome the challenges in their delivery, efficacy, and safety.

Lumbar disc arthroplasty (LDA) has emerged as a motion-sparing alternative to lumbar fusion. Although LDA may be amenable to the ambulatory surgical setting, to date no study has identified the factors predisposing patients to extended hospital stay.A national surgical quality improvement database was queried from 2011 to 2019 for patients undergoing elective, single-level, primary LDA. Univariate and multivariate logistic regression analyses were performed to elucidate predictors of length of stay (LOS) at or above the 90th percentile of the study population (3 days). Secondary study endpoints included rates of complications, as well as predictors and reasons for unplanned reoperation within 30 days.A total of 630 patients met eligibility criteria for the study, of whom 517 (82.1%) had LOS3 days and 113 (17.9%) had LOS ≥3 days. Multivariate logistic regression revealed associations between prolonged hospitalization and postoperative diagnosis of degenerative disk disease, obesity, Hispanic identity, and operation length120 minutes. Before discharge, patients with LOS ≥3 days were more likely to have venous thromboembolisms, pneumonia, surgical site infections, and reoperations. Independent predictors of reoperation were wound infections, diabetes, and smoking.Complications following elective single-level LDA are relatively rare, with few extended hospitalizations being attributable to any specific complication. Risk factors for prolonged LOS appear to be related to diagnosis and surgical time rather than to modifiable preoperative comorbidities. Conversely, unplanned reoperations within 30 days are associated with optimizable perioperative factors such as smoking, diabetes, and surgical site infection.

To analyze the clinical and biomechanical outcome of professional athletes after lumbar total disk replacement, with a focus on restoration of the functional activity.This nonrandomized retrospective single-center study included 11 professional athletes who underwent lumbar disc replacement surgery using the prosthesis M6-L (Spinal Kinetics, Schaffhausen, Switzerland). The average postoperative follow-up was 3.18 ± 1.14 years. The following outcomes were evaluated: intensity of pain in the lumbar spine and lower limbs, Oswestry Disability Index, Short-Form 36, complications, time of return to previous sports activity, range of movement, degree of lumbar lordosis, degenerative changes of the adjacent levels, and degree of heterotopic ossification.The operated patients reported significant decrease of pain on visual analog scale (P0.001) as well as significant improvement of Oswestry Disability Index (P = 0.001) and Short-Form 36 (P0.001). For the duration of follow-up, the patients maintained segmental range of motion at L4-L5 (P = 0.04) and L5-S1 (P = 0.03) levels. There was also some statistically insignificant increase of global lumbar lordosis (P = 0.84). We did not identify any significant degeneration of the adjacent intervertebral disks (P0.05) or progression of the facet joint degenerative changes at the implantation level and in the adjacent segments (P0.05). One patient (9.1%) developed grade I heterotopic ossification 5 years after surgery and in 1 patient (9.1%), a lesion of superior hypogastric plexus was recorded. The average time of return to previous sports activity was 9.72 ± 3.03 weeks.Total lumbar disc replacement using M6-L prosthesis in professional athletes made it possible to achieve statistically significant reduction of pain and facilitated early return to normal sports activities. In our opinion, preservation of movement of the operated lumbar segment can help to reduce the mechanical stress with beneficial impact on the rate of degeneration of the adjacent level.

Background Narrowing of intervertebral space height (ISH) is an important pathological change in degenerative spinal disease, and ideal intraoperative distraction and postoperative intervertebral space maintenance is one of the most expectant goals pursued by spinal surgeons. The effect of postoperative ISH changing on the clinical and radiological outcomes after cervical disc replacement is not fully understood, however. Methods In this study, the height variation and general trend of postoperative ISH in all patients were analyzed. The patients were divided into 3 groups based on the change of postoperative intervertebral space height (ISH)—group A (ISH 4mm)—and the clinical and radiographic results compared among the 3 groups. Results A total of 120 consecutive patients with symptomatic cervical disc disease were included in this study. The results showed that the mean ISH increased significantly from 0.729 mm before surgery to 1.143 mm at 1 week, then gradually decreased to 1.032 mm at 3 months, 0.980 mm at 6 months, 0.760 mm at one year, and 0.750 mm at the final follow-up. The average postoperative Neck Disability Index (NDI) was 19.73 ± 0.81, 13.74 ± 4.94, 17.19 ± 4.22, respectively, in the 3 groups at 1 year after surgery and the average range of motion (ROM) was 5.44° ± 3.85° in group A, 9.34° ± 4.38° in group B, and 6.51° ± 4.38° in group C. The mean diameter of the intervertebral foramen was 6.54 ± 1.86 mm in group A, 9.63 ± 2.38 mm in group B, and 9.31 ± 1.68 mm in group C. Degeneration at the superiorly adjacent disc level was observed in 13.51% patients in group A, 9.37% in group B, and 21.05% in group C. Degeneration at the inferiorly adjacent level was radiographically identified in 21.62% in group A, 14.06% in group B, and 26.32% in group C. Conclusions This study revealed that cervical disc replacement cannot maintain the intervertebral disc height obtained immediately after surgery. There is no obvious correlation between the change in intervertebral space height and clinical efficacy in the early postoperative stage. Nonetheless, the intervertebral disc height may affect the NDI index 1 year after surgery. If the postoperative intervertebral space height change can be maintained at 2–4 mm at 1 year, satisfactory ROM, intervertebral foramen diameter, and relatively low adjacent segment degeneration may be obtained after cervical disc replacement.

Background Extended length of stay (LOS) after surgery is costly to the health care system and can be distressing to the patient and family. Previous studies have shown conflicting data on factors associated with increased LOS and are limited by using multiple different surgeries. Our study seeks to analyze factors that are associated with extended LOS. Objective The objective of this study was to analyze data from 2 Food and Drug Administration trials of one-level cervical surgery to identify risk factors that are associated with extended LOS in the hospital. Methods Extended LOS was defined to be >1 day. Patients with LOS ≤1 day were compared with those with LOS >1 day. Data from the BRYAN and Prestige ST Trial (n = 1004) were analyzed. Subjects with LOS ≤1 day were compared with those with LOS >1 day. Variables analyzed for their effect on LOS included demographic characteristics, patient-reported outcome measures, preoperative medical conditions, preoperative neurologic status, and intraoperative factors. Results A total of 912 patients (90.84%) had an LOS ≤1 day and 92 patients (9.16%) had an extended LOS >1 day. Weak narcotic medication use (P = 0.021; odds ratio [OR], 1.72), Nurick gait (P = 0.019; OR, 1.796), and operative time (P Conclusions Nurick gait, operative time, and history of weak narcotic use are associated with extended hospital stay. These data may be useful in preoperatively counseling patients, developing quality metrics for hospitals, and helping create financial models for cost/diagnosis-related group reimbursement for single-level anterior cervical surgery.

Increasing costs put the value of spine surgery under scrutiny. In health economics, cost-effectiveness analyses (CEA) are used to compare the value of competing procedures. However, inconsistent methodology prevents standardization and implementation of recommendations. The goal of this study is to perform a systematic review of all U.S. CEAs in spine surgery reported to date, highlight their strengths and weaknesses, and define metrics essential for high-quality CEAs.We followed AMSTAR systematic review methods, identifying all U.S. spine surgery CEAs reported to March 2019 with a structured, reproducible search of PubMed, Embase, and the Tufts CEA Registry.We identified 40 CEA studies. Twelve (30%) used outcome data from a randomized controlled trial. To calculate costs, 22 (55%) used allowed charges but costing methods were often unclear or imprecise. Studies applying discounting had mean follow-up of 5.92 years compared with 3.00 years for studies without. Eleven of 15 (73%) cervical studies compared cervical disc arthroplasty with anterior cervical discectomy and fusion, finding cervical disc arthroplasty to be cost-effective ($100,000/quality-adjusted life year) for 1-level and 2-level procedures. Eleven of 25 lumbar studies (44%) compared operative with nonoperative interventions for intervertebral disc herniation, lumbar stenosis, and lumbar spondylolisthesis. Lumbar studies comparing surgical with nonoperative intervention found surgery at least cost-effective for intervertebral disc herniation and lumbar stenosis, but cost-effective only for lumbar spondylolisthesis at 4 years follow-up. Most studies (70%) lacked appropriate sensitivity analyses.Costing methodology remains obscure and inconsistent and incremental cost-effectiveness ratio results incomparable. The language of costing methodology must be standardized and sensitivity analyses of outcome and cost inputs mandatory for publication.

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 (ΔCobb0) after CDA. These patients with increased cervical lordosis (ΔCobb0) after CDA had higher grades of ABL.

OBJECTIVE: We sought to determine the safety and effectiveness of the Flexible Cervical Implant in 1- or 2-level cervical segments. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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

Objective Anterior cervical discectomy and fusion (ACDF) has been a widely accepted procedure for the treatment of cervical disc diseases. However, due to several reports regarding postfusion exacerbation of adjacent segments, a motion-preserving prosthesis was developed. In the present retrospective analysis, total disc replacement (TDR) using ActivC (Aesculap AG, Tuttlingen, Germany) was compared with ACDF using a stand-alone cage. Methods Among patients diagnosed with cervical disc diseases, those who received either ACDF or TDR at a single level between C3 and C7 from January 2010 to December 2015 were reviewed. Clinical outcomes were assessed using the visual analogue scale for arm and neck pain and the neck disability index. Clinical scales, lateral neutral, and flexion–extension radiographs were taken for all patients preoperatively and 2 months, 6 months, 1 year, and 2 years postoperatively. Global lordosis, C2–C7 Sagittal vertical axis, and T1 slope were measured on lateral neutral radiographs. The segmental range of motion (ROM) of the operated level, cranial adjacent level, and caudal adjacent level were defined as the difference between Cobb angles on flexion–extension lateral radiographs. Results A total of 53 patients (mean age 48.5 years) were reviewed. Thirty patients were treated with ACDF and the remaining 23 patients received TDR. At the 2-year follow-up, the segmental ROM of operated level was significantly preserved in the TDR group compared with the ACDF group (P = 0.007). Conversely, no significant differences in the ROM at the adjacent segments were observed between the TDR and ACDF groups (P > 0.05). The clinical outcome was excellent in both ACDF and TDR groups and was maintained until the 2-year follow-up. Conclusions In the present study, TDR using ActivC showed successful motion preservation at the operated level and equivalent results were observed with ACDF based on clinical and radiologic results.

The cause of postoperative heterotopic ossification (HO) after cervical disc replacement (CDR) is unclear. The aim of the present study was to investigate the incidence of HO, its clinical significance, and whether the degree of preoperative degeneration was associated with its occurrence.Patients who had undergone CDR using the Prestige-LP disc with a minimum of 48 months of follow-up were included. The patients were divided into 2 groups stratified by the presence of HO. The clinical outcomes (visual analog scale for neck and arm pain, neck disability index, and Japanese Orthopaedic Association scores) and radiographic parameters were collected and analyzed pre- and postoperatively and compared between the 2 groups. The preoperative degeneration at the operated levels was evaluated using the Kellgren-Lawrence scale and Miyazaki magnetic resonance imaging grading system.A total of 69 patients (89 levels) were identified, and the average age at surgery was 45.8 years. The overall incidence of HO at the final follow-up visit was 37.7% (26 of 69 of patients), and an increasing incidence and severity of HO was observed during the follow-up period. Significant and maintained improvements for all clinical outcome measures were observed, and the presence of HO did not influence these improvements. Segments with greater severe preoperative degeneration had a greater incidence of HO (P0.01). However, no statistical significant correlation between the degree of preoperative degeneration and the grade of HO was observed.The presence of HO after CDR was a relatively frequent finding at the final follow-up visit but did not influence patients' improvements. Segments with higher grades of preoperative degeneration had a greater incidence of HO; thus, HO is likely a reflection of the degeneration process.

To identify radiological factors and functional outcomes associated with good results after implantation of a single lumbar disc prosthesis or a hybrid construct (anterior lumbar interbody fusion and lumbar disc prosthesis) in the setting of painful degenerative lumbar discopathy.This single-center, retrospective 10-year study included 92 patients ˃18 years old with chronic low back pain evolving for at least 1 year. The patients had degenerative disc disease and had failed conservative treatment and underwent lumbar arthroplasty. Radiographic and clinical outcomes were assessed preoperatively and 1 year after surgery. Functional evaluation was based on the Oswestry Disability Index (ODI) and a numerical rating scale. Radiological analysis was based on lumbar x-rays and magnetic resonance imaging parameters. Patients were assigned to 2 groups according to the reduction in ODI score (15 points or15 points), and statistical analysis was done in both groups to find predictive radiological factors for a satisfactory functional outcome.Clinically, 60 patients (65.2%) had a satisfactory functional result and 32 patients (34.8%) had a poor outcome according to ODI score. Radiographically, gain in segmental lordosis was statistically associated with good functional outcomes (8.9° for ODI decrease15 vs. 3.2° for ODI decrease15).This study determined that gain in segmental lordosis is associated with a satisfactory functional outcome after a single-level lumbar disc prosthesis or a hybrid construct. Our study demonstrates that segmental lordosis gain may represent a significative useful positive predictor factor of patient outcome.

To compare clinical and imaging outcomes after cervical disc replacement (CDR) in patients with different Hounsfield units (HU).We performed a retrospective study of patients with cervical degenerative disc disease treated by 1-level and 2-level Prestige-LP arthroplasty. The patients were divided into group A (HU320), group B (HU 320-347), and group C (HU347) according to the results of cervical vertebral HU measurement in the literature, and the clinical and radiographic results were compared among the 3 groups.A total of 127 patients were reviewed, comprising 13 patients in group A, 31 patients in group B, and 83 patients in group C. The clinical parameters were significantly improved postoperatively in the 3 groups (P0.05). However, no significant differences were found among the 3 groups at the final follow-up (P0.05). The mean postoperative intervertebral space height (ISH) was 4.76 ± 0.45 mm, 5.23 ± 0.81 mm, and 6.26 ± 1.12 mm in the 3 groups, respectively. The postoperative ISH in group C was significantly higher than those in the other groups at the final follow-up (P0.001). One patient in group A and 1 patient in group B had implant subsidence, and degeneration at the inferiorly adjacent level was radiographically identified in 30.77% patients in group A, 16.13% patients in group B, and 9.64% patients in group C. However, there were only significant differences between group A and group C in subsidence (P = 0.011) and occurrence of adjacent level degeneration (P = 0.032).The HU value has a large variation range among the patients with T-score ≥ -2.5. We found significantly increased rates of implant subsidence, loss of ISH, and adjacent segment degeneration in patients with lower HU value undergoing CDR. However, these radiographic complications did not predispose patients with lower HU value to worse clinical outcomes. Routine application of HU combined with dual-energy X-ray absorptiometry measurement to evaluate bone quality may help to screen the optimal candidates for CDR and reduce the implant-related complications.

Heterotopic ossification (HO) is a potential and severe complication of cervical disc replacement (CDR). However, the underlying mechanism of CDR and its association with preoperative disc height loss (DHL) and postoperative degree of distraction remain unclear. We hypothesized that DHL and postoperative degree of distraction could predict HO after CDR.Data were obtained from 127 patients who underwent single-level CDR with a minimum follow-up of 2 years. DHL and adjusted degree of distraction (ADD) were obtained from lateral radiographs, and HO was evaluated at the last follow-up appointment. Receiver operating characteristic curves were calculated to verify the diagnostic value of DHL and ADD in predicting HO.Both DHL and ADD were significantly larger in the HO group than in the non-HO group (P0.05). DHL ≥24.97% increased the risk of HO by 5 times (P = 0.003, 95% confidence interval 1.62-15.49), and ADD ≥36.67% increased the risk of HO by 3.87 times (P0.001, 95% confidence interval 1.81-8.27). A combined DHL and ADD (combined parameter) cutoff of 60.36 had a sensitivity of 87.18%, specificity of 67.35%, and area under the curve of 0.77 for predicting HO.DHL and ADD are associated with the development of HO after CDR. The cutoff value of DHL may narrow the criteria for CDR with the aim of reducing HO formation. The combined parameter may help surgeons to select the most suitable implant height to reduce the prevalence of HO.

Objective To investigate whether anterior bone loss (ABL) in cervical discarthroplasty (CDA) in 2-level hybrid surgery (HS) is affected by adjacent fusion in vivo compared with 1-level CDA alone. Methods A total of 180 patients undergoing either a 1-level CDA or contiguous 2-level HS were retrospectively reviewed. The clinical and radiographic outcomes were collected preoperatively and at routine postoperative intervals of 1 week, 3, 6, and 12 months, and at the last follow-up. The initial and postoperative radiographs were compared to determine the incidence and degree of ABL. Results ABL was identified in 68.7% of CDA cases (37.9% mild, 34.8% moderate, and 27.3% severe) and 44.0% of HS cases (54.1% mild, 27.0% moderate, and 18.9% severe). Sex, age, bone mineral density, operation time, blood loss, postoperative alignment, and range of movement at the arthroplasty segment were not related to the incidence of ABL. According to the logistic regression analysis results, ABL showed a significant correlation with the surgery type and body mass index. However, there was no significant difference in the incidence and degree of ABL with or without an adjacent fusion level. Compared with preoperative values, clinical outcome scores significantly improved after surgery in both the HS and CDA groups. No definite clinical effect associated with ABL was found. Conclusions ABL was common in both CDA and HS. Although HS had a lower incidence rate and degree than did CDA, the fusion location in HS did not affect the ABL of adjacent CDA.

Background: Patient satisfaction is becoming an increasing factor worthy of consideration when evaluating the surgical quality. The correlation between patient satisfaction and surgical outcomes 5 years after cervical hybrid surgery (HS), which incorporates anterior cervical decompression and fusion and cervical disk arthroplasty techniques in multilevel cervical degenerative disk disease, has not been evaluated. Methods: The aim of this study was firstly to analyze prospectively collected data from a sample of patients (n = 50) treated with cervical HS for selected cases of radiculopathy and myelopathy in order to evaluate pain levels of patients, using the Neck and Arm Pain scale as an expression of visual analog scale. Secondly, we aimed to evaluate health-related quality of life, via the short-form 36, Neck Disability Index, and Japanese Orthopedic Association score. Patients were followed up for more than 5 years. Intraoperative parameters, clinical features, and outcome scores were recorded. Radiologic investigations including disk height and changes in adjacent disk spaces were assessed. Results: Clinical improvements were observed in all outcomes; significant improvements on the Neck Disability Index, visual analog scale, short-form 36, and Japanese Orthopedic Association scores were maintained at 5 years (P < 0.05). The mean disk height resulted restored in all the cases. Temporary dysphagia was rarely observed (3%). No surgery for adjacent-level disease was required. There was no significant difference in the outcomes between radiculopathy and myelopathy groups (P > 0.05). Conclusions: HS is an effective and safe procedure for the treatment of multilevel cervical degenerative disk disease. Such a surgical construct offers postoperative improvement on pain levels and health-related quality of life.

Heterotopic ossification (HO) and anterior bone loss (ABL) are 2 complications in cervical disc replacement (CDR), which have impacts on the clinical outcomes. Physiologically, bone formation (HO) and bone loss are 2 sides of bone remodeling. However, clinically, some patients experienced anterior HO (AHO) after CDR, whereas other patients experienced ABL. Is there any factor in determining the fate of the vertebral bone in the anterior region? Is ABL the opposite of AHO? This study aims to answer these questions.Seventy patients with 1-level Prestige-LP CDR were retrospectively reviewed and were divided into an AHO group or ABL group. Radiologic outcomes, including cervical lordosis, sagittal vertical axis, functional spine unit angle, disc angle, range of motion, implant migration, subsidence, and adjacent segment degeneration were evaluated. Patient-reported clinical outcomes were also evaluated.AHO group showed significantly lower disc angle after surgery (0.9° ± 4.2°), compared with ABL group (6.7° ± 4.7°) (P0.001). The preoperative segmental range of motion was significantly higher in the AHO group (10.2° ± 3.3°) than in the ABL group (8.2° ± 3.7°) (P = 0.042). No correlation was observed between clinical outcomes and the presence of anterior bone remodeling. Both groups maintained cervical alignment and functional spine unit angle during long-term follow-up. No significant difference was found in the end plate preparation, implant subsidence, migration, or adjacent segment degeneration rate between the 2 groups.The differences in the disc angle showed the role of mechanical load in the anterior bone remodeling. Combined the results with the basic concepts of bone remodeling, ABL may be the opposite of AHO.

Mobi-C cervical disc arthroplasty (MCDA) is an alternative to anterior cervical discectomy and fusion (ACDF). This study evaluated the effectiveness and safety of MCDA and ACDF for symptomatic cervical degenerative disc disease.Databases were systematically searched for randomized controlled trials. Studies were included based on eligibility criteria. Risk of bias assessment and quality of evidence assessment were performed.Four studies with 785 patients were included. For clinical outcomes, MCDA were superior to ACDF with fewer subsequent surgical interventions (P0.00001), lower neck pain scores (P = 0.01), lower incidences of adjacent segment degeneration at both superior and inferior levels (P = 0.0003 and P = 0.01, respectively), greater range of motion of the operated segment (P0.0001), and higher patient satisfaction (P = 0.007). No significant differences were observed between groups regarding operative time, blood loss, duration of hospitalization, and neck disability index and arm pain scores (P0.05). Subgroup analyses indicated that for patients with 2-level cervical degenerative disc disease, MCDA demonstrated lower neck disability index and arm pain scores and higher patient satisfaction (P0.05) compared with ACDF.MCDA had fewer subsequent surgical interventions, lower neck pain scores, lower incidences of adjacent segment degeneration at superior and inferior levels, greater range of motion, and higher patient satisfaction scores than ACDF. MCDA was similar to ACDF regarding operative time, blood loss, duration of hospitalization, and neck disability index and neck pain scores.

To assess the mid-long-term follow-up of the safety and efficacy of anterior cervical discectomy and fusion (ACDF), cervical artificial disc replacement (CADR) and hybrid surgery (HS) for bilevel cervical degenerative disc disease (cDDD).77 patients who underwent ACDF, HS, and CADR were retrospectively reviewed. Clinical effects were evaluated based on Neck Disability Index (NDI), Visual Analog Scale (VAS), and Japanese Orthopedic Association (JOA) scores and the Odom criteria. Radiographic outcomes were evaluated, including cervical range of motion (ROM), ROM in the operative and adjacent segments, incidence of degeneration in the adjacent segments (ASD), and heterotopic ossification (HO).NDI, VAS, and JOA scores significantly improved in all patients after surgery without significant differences between groups. The excellent-to-good ratio in the Odom scale was 28/30 for the HS group, 30/33 for the ACDF group, and 13/14 for the CADR group. No significant differences in clinical outcomes or complication were found between groups (P0.05). Furthermore, the HS and CADR groups had less decreased ROM in the cervical and operative segments and less compensatory ROM in adjacent segments (P0.05). By contrast, the ACDF group had decreased ROM in the cervical and operative segments and significantly increased ROM in adjacent segments (P 0.05). Moreover, the incidence of ASD was higher in the ACDF group, but the difference was not statistically significant (P0.05). HO was found in 10 patients (33.3%) in the HS group and 5 patients (35.7%) in the CADR group.HS was superior to ACDF with regard to equivalent clinical outcomes in the mid-long-term follow-up. Furthermore, HS was superior in the maintenance of ROM and had less impact on its adjacent segments. The efficacy of HS is similar to that of CADR.

Low back pain is the principal cause of long-term disability worldwide. We intend to address one of its main causes, degenerative disk disease, a spinal condition involving degradation of an intervertebral disk. Following unsuccessful conservative treatment, patients may be recommended for surgery. The two main surgical treatments for lumbar degenerative disk disease are lumbar fusion: traditional standard surgical treatment and lumbar disk arthroplasty, also known as lumbar total disk replacement. Lumbar fusion aims to relieve pain by fusing vertebrae together to eliminate movement at the joint, but it has been criticized for problems involving insignificant pain relief, a reduced range of motion, and an increased risk of adjacent segment degeneration. This leads to development of the lumbar total disk replacement technique, which aims to relieve pain replacing a degenerated intervertebral disk with a moveable prosthesis, thus mimicking the functional anatomy and biomechanics of a native intervertebral disk. Over the years a large range of prosthetic disks has been developed. The efficacy and current evidence for these prostheses are discussed in this review. The results of this study are intended to guide clinical practice and future lumbar total disk replacement device choice and design.

Objective Treatment of cervical radiculopathy with disk arthroplasty has been approved by the U.S. Food and Drug Administration since 2007. Recently, a significant increase in clinical data including mid- and long-term follow-up has become available, demonstrating the superiority of disk arthroplasty compared with anterior discectomy and fusion. The aim of this project is to assess the nationwide use of cervical disk arthroplasty. Methods The University Healthcare Consortium database was accessed for all elective cases of patients treated for cervical radiculopathy caused by disk herniation (International Classification of Diseases [ICD] 722.0) from the fourth quarter of 2012 to the third quarter of 2015. Within this 3-year window, temporal and socioeconomic trends in the use of cervical disk replacement for this diagnosis were assessed. Results Three thousand four hundred forty-six cases were identified. A minority of cases (10.7%) were treated with disk arthroplasty. Median hospital charges were comparable for cervical disk replacement ($15,606) and anterior cervical fusion ($15,080). However, utilization was seen to increase by nearly 70% during the timeframe assessed. Disk arthroplasty was performed in 8% of patients in 2012 to 2013, compared with 13% of cases in 2015. Disk replacement use was more common for self-paying patients, patients with private insurance, and patients with military-based insurance. There was widespread variation in the use of cervical disk replacement between regions, with a nadir in northeastern states (8%) and a peak in western states (20%). Conclusion Over a short, 3 -year period there has been an increase in the treatment of symptomatic cervical radiculopathy with disk arthroplasty. The authors predict a further increase in cervical disk arthroplasty in upcoming years.

Objective The purpose of this study is to discuss the causes of implant migration after cervical arthroplasty with clinical cases. Methods The patients who underwent cervical arthroplasty operations in our department between 2006 and 2015 because of cervical disk disease were retrospectively analyzed. The patients who were determined to be symptomatic of implant migration were evaluated. Results Symptomatic implant migration was detected in 5 of 163 (0.3%) patients who underwent cervical disk arthroplasty, and these patients also underwent reoperation. In 4 patients who underwent reoperation, the prosthesis was removed, and an anterior fusion was made. The prosthesis was only removed in 1 patient. Conclusions The following situations should be considered in the prevention of dislocation and migration of the implant in cervical arthroplasty: protection of the structure of the end plate, selection of the appropriate implant size, and proper surgical construction. In the preoperative period, computed tomography scan may be useful for determining the implant size and details of the bone structure. Foreign body reactions or postoperative trauma may be a rare and unpreventable reason for prosthesis dislocation despite all of the preoperative and perioperative measures and well-made prosthesis designs.

Background Cervical disk arthroplasty is now a widely accepted alternative to anterior cervical interbody fusion, which is known to reduce normal cervical motion and increase the incidence of adjacent segment disease. Although multiple studies report the use of cervical disk arthroplasty to treat multilevel cervical disease, this is the first report in the literature detailing the placement of multiple, noncontiguous artificial disks. Case Description We describe a 41-year-old male who presented with myelopathy and left upper extremity radiculopathy resulting from 2 cervical disk herniations separated by a normal intervening level. He underwent an anterior cervical diskectomy and placement of an artificial disk prosthesis at cervical (C) 4-5 and C6-7 while leaving C5-6 intact. Conclusions This approach serves to preserve cervical motion, spinal stability, and lordosis across all 3 levels, thus demonstrating that it is a viable alternative to a multilevel anterior cervical interbody fusion.

Objective To evaluate clinical and radiologic results as well as biomechanical changes after anterior cervical discectomy and fusion (ACDF), cervical disc replacement (CDR), and posterior cervical foraminotomy (PCF) and/or discectomy in individuals with unilateral single-level cervical radiculopathy. Methods A total of 97 patients received surgical treatment for unilateral intolerable radiculopathy between February 2012 and August 2017. Clinical outcomes included Neck Disability Index (NDI), visual analogue scale (VAS) for neck and arm pain, and modified Odom's criteria. Range of motion (ROM) of the whole cervical (C-ROM), operated segment (S-ROM), and upper and lower adjacent segment (U-ROM and L-ROM) were measured. Results A total of 55 ACDFs, 21 CDRs, and 21 PCFs were performed. Clinical improvement in NDI and VAS scores were significant after surgery; however, there was no statistical significance among groups. Satisfaction rate (based on Odom's criteria) of PCF (76.2%) was inferior to that of ACDF (90.9%) and CDR (90.5%) without statistical difference. S-ROM, U-ROM, and L-ROM were slightly better in the CDR and PCF groups, without statistical significance. C-ROM significantly increased in CDR group (P = 0.04) and slightly increased in PCF group (P = 0.27). In the ACDF group, C-ROM decreased (P = 0.21) and on the contrary, the U-ROM and L-ROM increased (P > 0.05). Conclusions ACDF, CDR, and PCF resulted in pain relief and improvement in neck function for patients with unilateral radiculopathy. Comparatively, ACDF provides the lowest reoperation rate. CDR is effective in ameliorating cervical ROMs. PCF has a greater probability of reoperation; however, ROM after surgery is better than with ACDF.

Objective To determine any differences in self-reported dysphagia in patients treated with single-level anterior cervical decompression with different zero-profile implants (arthroplasty vs. arthrodesis) and identify risk factors for postoperative dysphagia. Methods A total of 112 patients with 1-level cervical degenerative disc disease were included in the prospective study. The dysphagia conditions and radiologic results were assessed using Bazar dysphagia scoring system, the Swallowing Quality of Life scores, cervical alignment (CA), segmental angle, and prevertebral soft tissues swelling (PSTS). All these parameters were compared before and after surgery in the respective group, which were also compared between the 2 groups. Correlations between the confounding factors and postoperative dysphagia were analyzed. Results No significant differences existed in preoperative or initially postoperative dysphagia rate and scores between the 2 groups ( P > 0.05). However, the dysphagia rate and scores of cervical disc arthroplasty was better than those of fusion at postoperative day 7. Heavy smoker, PSTS change (≥5 mm), or CA change (≥5 degrees) was prone to have postoperative dysphagia. Conclusions Postoperative dysphagia remains a common incidence, despite advances in instrumentation technologies. However, cervical disc arthroplasty is superior to anterior cervical discectomy and fusion in ameliorating the symptom of dysphagia in the early postoperative term. Heavy smoker, PSTS change (≥5 mm), and CA change (≥5 degrees) were important predictors of postoperative dysphagia.

Objective The combination of anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) has been demonstrated to be effective for multilevel cervical spondylotic myelopathy (CSM); however, the combination of ACCF and cervical disc arthroplasty (CDA) for 3-level CSM has never been addressed. Methods Consecutive patients (>18 years of age) with CSM caused by segmental ossification of posterior longitudinal ligament (OPLL) and degenerative disc disease (DDD) were reviewed. Inclusion criteria were patients who underwent hybrid ACCF and CDA surgery for symptomatic 3-level CSM with OPLL and DDD. Medical and radiologic records were reviewed retrospectively. Results A total of 15 patients were analyzed with a mean follow-up of 18.1 ± 7.42 months. Every patient had hybrid surgery composed of 1-level ACCF (for segmental-type OPLL causing spinal stenosis) and 1-level CDA at the adjacent level (for DDD causing stenosis). All clinical outcomes, including visual analogue scale of neck and arm pain, Neck Disability Index, Japanese Orthopedic Association scores, and Nurick scores of myelopathy, demonstrated significant improvement at 12 months after surgery. All patients (100%) achieved arthrodesis for the ACCF (instrumented) and preserved mobility for CDA (preoperation 6.2 ± 3.81° vs. postoperation 7.0 ± 4.18°; P = 0.579). Conclusions For patients with multilevel CSM caused by segmental OPLL and DDD, the hybrid surgery of ACCF and CDA demonstrated satisfactory clinical and radiologic outcomes. Moreover, although located next to each other, the instrumented ACCF construct and CDA still achieved solid arthrodesis and preserved mobility, respectively. Therefore, hybrid surgery may be a reasonable option for the management of CSM with OPLL.

There have been several clinical trials as well as observational studies that have compared the outcomes of different cervical disc replacement (CDR) devices with anterior cervical disc replacement and fusion (ACDF). Although the results of these studies have provided sufficient evidence for the safety of CDR, there is still a lack of consensus in terms of longer-term outcomes, with studies providing equivocal results for the 2 procedures. In the current study, we used a novel methodology, a meta-epidemiologic study, to investigate the impact of study characteristics on the observed effects in the literature on CDR and ACDF.Data were abstracted from available meta-analyses regarding author, study author, year, intervention events, control events, and sample size, as well as year and geographic location of each study within the meta-analyses. We grouped the studies based on median year of publication as well as the region of the submitting author(s). Odds ratios, 95% confidence intervals (CIs), and standard errors of individual studies were calculated based on the number of events and sample size for each arm (ACDF or CDR). Further, results of outcomes from individual studies were pooled and a meta-analysis was conducted. Ratio of odds ratio (ROR) was used to assess the impact of each of these factors on estimates of the study for CDR versus ACDF.A total of 13 meta-analyses were analyzed after exclusions. Using the results from 10 meta-analyses, we found that studies published before 2012 reported significantly lower odds of a reoperation after CDR (vs. ACDF), compared with studies published after 2012 (ROR, 0.51; 95% CI, 0.38-0.67; P0.001). We did not observe a significant impact of study year on difference in estimates between CDR and ACDF for adjacent segment disease (ROR, 0.99; 95% CI, 0.64-1.55; P = 0.465). The region of submitting author was also found to have no impact on results of published studies.These results indicate that there may be a publication bias regarding the year of publication, with earlier studies reporting lower reoperation rates for CDR compared with ACDF.

Background Cervical total disc arthroplasty (TDA), or cervical artificial disc replacement, is an alternative technique to anterior cervical discectomy and fusion for treatment of symptomatic degenerative cervical spine disease. The main goal of TDA is to maintain cervical motion and lower the risk of deterioration of adjacent levels. Granuloma formation on a cervical TDA is exceptional. Case Description A 48-year-old woman with left cervicobrachialgia underwent a double-level TDA (M6-C Artificial Cervical Disc) on C5-C6 and C6-C7 at another hospital in 2010. Two years later, she reported a recurrence of cervicalgia, which was refractory to conservative treatment by rigid collar and analgesics. Cervical magnetic resonance imaging suggested a granulomatous formation on the C6-C7 prosthesis. She underwent removal of the C6-C7 prosthesis, which showed a rupture with nylon thread extrusion. An arthrodesis with plate was subsequently performed. Follow-up showed improvement of her clinical status. Histopathologic studies showed a giant cell granulomatous formation in contact with nylon threads described in hip, shoulder, and ankle arthroplasty. It has been described in 6 cases following lumbar TDA and 2 cases following cervical TDA. Conclusions We report a third case of granulomatous reaction on nylon thread extrusion after partial breakdown of a prosthesis for cervical TDA.

The aim of this study was to comprehensively compare the clinical and biomechanical efficiency of anterior cervical discectomy and fusion (ACDF) with anterior cervical disc replacement (ACDR) for treatment of multilevel cervical disc disease using a meta-analysis and systematical review.A literature search was performed using PubMed, MEDLINE, EMBASE, and the Cochrane Library for articles published between January 1960 and December 2017. Both clinical and biomechanical parameters were analyzed. Statistical tests were conducted by Revman 5.3. Nineteen studies including 10 clinical studies and 9 biomechanical studies were filtered out.The pooled results for clinical efficiency showed that no significant difference was observed in blood loss (P = 0.09; mean difference [MD], 7.38; confidence interval [CI], -1.16 to 15.91), hospital stay (P = 0.33; MD, -0.25; CI, -0.76 to 0.26), Japanese Orthopaedic Association scores (P = 0.63; MD, -0.11; CI, -0.57 to 0.34), visual analog scale (P = 0.08; MD, -0.50; CI, -1.06 to 0.05), and Neck Disability Index (P = 0.33; MD, -0.55; CI, -1.65 to 0.56) between the 2 groups. Compared with ACDF, ACDR did show increased surgical time (P = 0.03; MD, 31.42; CI, 2.71-60.14). On the other hand, ACDR showed increased index range of motion (ROM) (P0.00001; MD, 13.83; CI, 9.28-18.39), lower rates of adjacent segment disease (ASD) (P = 0.001; odds ratio [OR], 0.27; CI, 0.13-0.59), complications (P = 0.006; OR, 0.62; CI, 0.45-0.87), and rate of subsequent surgery (P0.00001; OR, 0.25; CI, 0.14-0.44). As for biomechanical performance, ACDR maintained index ROM and avoided compensation in adjacent ROM and tissue pressure.Multilevel ACDR may be an effective and safe alternative to ACDF in terms of clinical and biomechanical performance. However, further multicenter and prospective studies should be conducted to obtain a stronger and more reliable conclusion.

Lumbar total disk replacement is considered for the treatment of lumbar degenerative disk disease with the hope that by preserving motion, the long-term fusion complication of adjacent segment disease can be avoided. The complications of lumbar total disk replacement can be divided into approach-related and long-term complications. Little has been described about the complications and treatment for complications >10 years after the device has been implanted. Here we describe a transforaminal endoscopic diskectomy procedure for a patient presenting with foot drop 12 years after a L5-S1 total disk replacement.

Background Owing to its unique advantages, 2-level artificial cervical disc replacement (ACDR) is gaining attention. Among artificial discs designed for use in ACDR, the Food and Drug Administration–approved Prestige-LP Cervical Disc is widely used. There are no standard implantation sequences for 2-level ACDR using the Prestige-LP disc, and complications resulting from inappropriate implantation sequences remain unknown. Case Description A 45-year-old woman underwent continuous 2-level ACDR using the Prestige-LP disc and experienced anterior migration of a previously inserted artificial disc after secondary disc implantation at an upper segment owing to an inappropriate implantation sequence during surgery. Intraoperative radiographs showed stable index levels and artificial discs. We tapped the migrated disc back into its correct position and recommended a postoperative functional exercise plan to the patient. We followed the patient for 8 years to verify the safety of our solution. We developed an implantation strategy for 2-level ACDR to avoid this complication in the future. Conclusions During 2-level ACDR, a top-down sequence should be used to implant prostheses. When anterior disc migration occurs, intraoperative radiographs should be obtained to ensure stability of the index levels. If there is no instability, the migrated tab can be tapped back into its correct position. In addition, limiting motion rather than allowing intermittent movement of the neck for at least 3 months is important to promote union between bone and prosthesis.

Objective To systematically investigate the effect of 3-level hybrid constructs on the cervical spine biomechanics based on a validated model of the C3–C7 segments. Methods Three hybrid constructs with 2 U-shaped dynamic cervical implants and 1 cage were simulated. The 3 constructs were 1) Cage-U-U (cage implanted at the C3–C4 level and U-shaped dynamic cervical implants implanted at the C4–C5 and C5–C6 levels), 2) U-Cage-U, and 3) U-U-Cage. Biomechanical parameters including moments, cervical motions, and stresses in the facet and implants were analyzed in flexion and extension. Results The flexion and extension motions at artificial cervical disc replacement levels increased for all hybrid constructs when compared with those of intact model. However, the maximum increase was 52% with U-U-Cage model. At the unoperated adjacent level, the maximum motion increase in extension was 23% with the U-U-Cage model. Also, the U-U-Cage and U-Cage-U model generated more than 40% increase in terms of flexion motion at the adjacent level. The facet stress at the adjacent level increased by 28%, 20%, and 39% with the Cage-U-U, U-Cage-U, and U-U-Cage models, respectively. The moments required to reach the same motion as the intact model were significantly increased. Conclusions The study showed that the U-U-Cage model lead to more compensation in terms of motion and facet stress. Furthermore, the present results imply that when conducting the hybrid surgery, the segmental motions should be taken into account. Performing anterior cervical discectomy and fusion at the level whose motion is relatively small may decrease the compensation required at the adjacent level.

Background Finite element models have been widely used to predict biomechanical parameters of the cervical spine. Previous studies investigated the influence of position of rotational centers of prostheses on cervical biomechanical parameters after 1-level total disc replacement. The purpose of this study was to explore the effects of axial position of rotational centers of prostheses on cervical biomechanics after 2-level total disc replacement. Methods A validated finite element model of C3-C7 segments and 2 prostheses, including the rotational center located at the superior endplate (SE) and inferior endplate (IE), was developed. Four total disc replacement models were used: 1) IE inserted at C4-C5 disc space and IE inserted at C5-C6 disc space (IE-IE), 2) IE-SE, 3) SE-IE, and 4) SE-SE. All models were subjected to displacement control combined with a 50 N follower load to simulate flexion and extension motions in the sagittal plane. For each case, biomechanical parameters, including predicted moments, range of rotation at each level, facet joint stress, and von Mises stress on the ultra-high-molecular-weight polyethylene core of the prostheses, were calculated. Results The SE-IE model resulted in significantly lower stress at the cartilage level during extension and at the ultra-high-molecular-weight polyethylene cores when compared with the SE-SE construct and did not generate hypermotion at the C4-C5 level compared with the IE-SE and IE-IE constructs. Conclusions Based on the present analysis, the SE-IE construct is recommended for treating cervical disease at the C4-C6 level. This study may provide a useful model to inform clinical operations.

This study compared the radiologic parameters between preoperation and postoperation for patients who underwent multilevel cervical total disk replacement (MCTDR) and assessed which parameters were related to successful clinical outcomes after MCTDR.The study included a consecutive series of 24 patients who were treated with MCTDR following the diagnosis of multilevel cervical disk herniation or stenosis. Numeric Rating Scale, C2-7 sagittal vertical axis, range of motion (ROM) of C2-7 segment, and total disk replacement (TDR) implanted levels were evaluated at pre- and post-TDR. These parameters were compared between patients who experienced successful and unsuccessful pain relief.Numeric Rating Scale scores were reduced while C2-7 sagittal vertical axis improved significantly after MCTDR. C2-7 flexion was significantly decreased (P 0.05), while its extension showed trends toward considerable (P = 0.088) increase, thereby maintaining original C2-7 ROM without statistical significance. TDR flexion was decreased (P0.05), while its extension changes were stationary, consequently resulting in a significant decrease in TDR ROM (P0.05). The unsuccessful group showed markedly reduced ROM and lack of ROM angular change maintenance at both the C2-7 and MCTDR levels (P0.05) compared with the successful group.MCTDR was effective in reducing pain and improving cervical lordosis in patients with multilevel cervical disk herniation or stenosis. Despite a significant decrease in the flexion angle, it could maintain C2-7 ROM presumably by compensating with C2-7 extension angle increase. Clinical success after MCTDR was crucially related to retaining original C2-7 ROM and minimizing ROM angular changes at both the C2-7 and MCTDR levels.

Introduction Artificial disc replacements, which serve the function of separating vertebrae to allow for proper spinal alignment, can help treat debilitating low back pain in patients who have failed other conservative methods of treatment. A Swedish surgeon, Ulf Fernstrom, was the pioneer of artificial disc replacement, and his contribution in the form of Fernstrom balls dramatically altered spinal surgery and technique by showing the proper technique and implant that should be used for areas requiring motion in many planes. History of the Artificial Disc Ulf Fernstrom created his artificial disc inspired by the movement of the hip and knee joints. His implants attempted to restore disc spacing and articulation in patients who had failed conservative measures of treatment. Fernstrom balls were the first implants of their kind and represent the first attempt at artificial disc replacement. However, many surgeons and researchers questioned Fernstrom balls, claiming that their lack of elastic properties could damage patients. Conclusions Of the wide range of implants on the market for the intervertebral disc space, all designs and applications of products stem from the initial discovery made by Fernstrom, thus making him a pioneer in disc replacement.

Objective Total disc replacement (TDR) is typically indicated in young patients with a cervical soft disc herniation. There are few data on the activity level of patients after cervical TDR, in particular from young patients who are expected to have a high activity level with frequent exercising. The expectation is that returning to active sports after cervical TDR is not restricted. Methods Fifty patients were treated with a monosegmental cervical TDR at our department between May 2006 and March 2012. Clinical status and radiographic parameters were evaluated preoperatively and during follow-up. In addition, information was gathered regarding neck disability index, pain, a questionnaire concerning athletic aspects, and a modified Tegner activity score. The study design was a prospective case series. Results All patients were treated with the Prestige artificial cervical disc for a single-level soft disc herniation with radiculopathy. The average age was 40 years, and the mean follow-up period was 53 months (range, 26–96). The median neck disability index during follow-up was 5, and median visual analog scale for pain was 2. Two professional athletes, 20 semiprofessionals, 24 hobby athletes, and 5 patients with a very low activity level were treated. The median time to resumption of sporting activity was 4 weeks after surgery. All professionals and semiprofessionals recovered to their previous activity level. All of the 20 hobby athletes recovered to resume their sport participation. The modified Tegner preoperative score was 4 and the postoperative score was 3.5 ( P = 0.806). Conclusions We found that cervical TDR did not prohibit sporting activities. All patients recovered and were able to take part in their previous activities at an appropriate intensity level.

The aim of our study was to determine the presence of heterotopic ossifications (HO) in a series of patients with cervical disk arthroplasty treated with different type of prosthesis, as well as to analyze the most suitable systems for diagnosis.A retrospective study of patients with cervical disk disease treated with cervical arthroplasty between May 2005 and December 2009, was performed. Patients were divided into 3 groups, depending on the prosthesis implanted: (Group A: Baguera prosthesis, Group B: ProDisc prosthesis, and Group C: PCM prosthesis). The presence of heterotopic ossifications was evaluated with both, simple radiology and computed tomography.As a summary of the results on motion preservation, computed tomography scans showed that 63% of the cervical arthroplasties in Group A presented good mobility at the first check point (December 2010), whereas cervical arthroplasties in Group B and Group C had 74% and 65% severe motion restrictions, respectively (Grade III or Grade IV, according to McAfee classification). The differences between groups were statistically significant when comparing Groups A and B, and Groups A and C (P 0.05), but there were no differences between Groups B and C (P0.05). At the second check point (December 2014), the good mobility was just preserved in the 26% of the disk replacements (all in Group A).Our results showed that, although cervical disks provide optimal mid-term results, the incidence of HO seems to increase with time. Long term studies, with a larger sample size should be conducted to evaluate the appearance of HO and cervical motion after total disk replacement.

Background Arthrodesis is considered to be the reference treatment for degenerative disc disease (DDD), if the symptoms are refractory to conservative management. The drawback of arthrodesis is, besides a percentage of non-union, the reduced mobility that might generate an increased load and risk for degeneration of the adjacent levels. Total disc replacement (TDR) implants may overcome this problem. The long-term clinical effect and radiographic evaluation of motion preservation after implantation, however, have been subject to several nonconclusive studies. This study evaluated the long-term clinical and radiographic results and the safety of TDR with the Maverick prosthesis for surgical treatment of monosegmental DDD. Methods TDR was performed in 50 consecutive patients with monosegmental DDD using the Maverick device. Patients were followed prospectively for disability, quality of life, pain intensity and frequency, as well as working status and return to sports, during 48 months. Motion preservation was assessed on neutral and dynamic radiographs at 48 months. Results The disability, pain intensity and frequency, and quality of life improved significantly at the 6-week follow-up, which was maintained over the full 48 months following Maverick implantation. Preoperatively, 80% of the patients stopped working and 86% halted sports activities. Four years after surgery, 85% of patients were again working and 79% took up their normal sports activities. Radiographic assessment showed that motion at the index level is maintained 48 months after TDR. No major complications were encountered. Conclusion In this study, TDR with the Maverick prosthesis at one lumbar segment reduced pain and disability and improved quality of life as well as the general condition. Motion was preserved at the operated level, 48 months after surgery. The long-term effect on adjacent levels needs further follow-up.

Background Cerebrospinal fluid (CSF) leak during anterior cervical spine surgery can lead to complications, including wound breakdown, meningitis, headaches, need for lumbar drain, or additional surgery. These leaks can be difficult to manage given the limited field of view and lack of deep access. Herein, we describe 8 consecutive patients who underwent intraoperative repair of CSF leak, with no postoperative evidence of wound dehiscence or drainage. Methods A retrospective review was performed on 8 cases where CSF leak was encountered during an anterior cervical spine surgery. Patients had ossification of the posterior longitudinal ligament, intradural disk herniation, or dural ectasia. Intraoperative repair was as follows. First, CSF was drained to low pressure, and durotomy was covered by dural substitute and sealant agent. Then the interbody graft used was manually undersized in the anteroposterior dimension to allow for expansion of the agents used. Anterior instrumentation was then performed. Finally, a wound drain was anchored to a biologic bag for shoulder level passive drainage. Results In all 8 cases, there were no cases of wound dehiscence or CSF leak using this strategy. Likewise, there was no evidence of cord compression or neurologic deficits. No meningitis or persistent headaches were reported, and there was no need for lumbar drain placement at any time postoperatively. Conclusions Once durotomy is encountered during anterior spine surgery, draining the CSF to a low pressure followed by dural substitute with a sealing agent, followed by a smaller anteroposterior size graft is an effective strategy of preventing complications in an inescapable problem.