BACKGROUND CONTEXT Anterior cervical discectomy and fusion (ACDF) is a standard surgical procedure in the management of symptoms of cervical radiculopathy and myelopathy for patients that are unresponsive to conservative therapy. However adjacent segment disease (ASD) following ACDF remains of concern due to changes in cervical spine biomechanics. Hybrid surgery (HS) in contrast to ACDF has been proposed to reduce the risk of ASD and improve clinical outcomes. However, there is still no consensus on which technique is more safe and effective hence we aim to evaluate the safety, efficiency, and reliability of HS, with large number and most recent studies, to provide updated insights into its clinical application, especially for patients with multilevel cervical disc degeneration. PURPOSE This meta-analysis aims to critically review and summarize the literature comparing the outcomes of anterior cervical discectomy and fusion (ACDF) versus hybrid surgery (HS) in the treatment of multilevel cervical degenerative disc disease. It also aims to address the contradictions and inconsistencies in the previous findings by including more recent studies and studies with long term follow up. This study will compare both clinical and radiographic parameters, including the rate of adjacent segment degeneration (ASD) and postoperative complications to provide a comprehensive evaluation of the two surgical approaches. STUDY DESIGN/SETTING Meta-analysis and systematic review. PATIENT SAMPLE N/A. OUTCOME MEASURES The following outcomes were compared: operation time, blood loss, length of hospital stay, C2-C7 Sagittal Vertical Axis (SVA), range of motion (ROM), cervical lordosis, T1 slope and superior and inferior ROM, major complications, reoperation, and incidence of ASD, dysphagia and heterotrophic ossification. METHODS This meta-analysis was made in compliance to the PRISMA guidelines. We included 21 studies which compared ACDF versus hybrid surgery among patients with multilevel continuous cervical spondylosis involving disc degeneration. The following outcomes were compared using pooled mean difference: operation time, blood loss, length of hospital stay, C2-C7 Sagittal Vertical Axis (SVA), range of motion (ROM), cervical lordosis, T1 slope and superior and inferior ROM. Pooled risk ratio was used for the following: major complications, reoperation, and incidence of ASD, dysphagia and heterotrophic ossification. To enhance reliability of results contour-enhanced funnel plots, Egger’s and Begg’s tests, meta-regression, sensitivity and subgroup analyses were performed. RESULTS The pooled overall mean difference which showed significant difference were shorter operative time in ACDF group (MD=-4.17s, 95%CI=-6.55 to -1.78 and p=0.0006), lower values of ROM in ACDF (MD=-4.15, 95%CI=-7.14 to -1.16 and p=0.007) and smaller reduction in superior segment ROM in the HS group showing preserved mobility postoperatively (MD=2.15, 95%CI=0.67 to 3.63 and p=0.004). The pooled risk ratio showed lower incidence of ASD in HS group (RR=1.24, 95%CI=1.00 to 1.54 and p=0.05). The other outcomes did not show statistically significant difference between the two surgical treatment indicating comparable outcome. CONCLUSIONS ACDF is a favorable option in lower operative time, blood loss while HS offer advantages in terms of range of motion, reduced risk of adjacent segment disease, reduced reoperation rate and dysphagia. Both treatment have comparable postoperative functional outcome. This suggests that HS is an effective alternative surgical management for the treatment of multilevel cervical spondylosis and disc disease to preserve cervical ROM and reduce the risk of adjacent disc degeneration in multilevel disc disease. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

Network meta-analysis of randomized controlled trials (RCTs) and comparative cohort studies. To compare different cervical disc prostheses based on sagittal alignment parameters, motion preservation, clinical results, and adverse events. Despite the growing adoption of cervical disc replacement (CDR) as an alternative to ACDF, surgeons currently lack evidence-based guidance for selecting among different CDR devices. PubMed, Cochrane Library, and Google Scholar searches were conducted for all published eligible studies till December 31, 2024. Surface under the cumulative ranking curve (SUCRA) values were used to rank implant performance. Meta-regression was used to examine correlations between radiographic and clinical parameters. Twenty-six studies (20 RCTs and 6 cohort studies) comprising 2892 CDR patients and 2638 ACDF patients with ACDF were analyzed. SUCRA analysis ranked M6-C as the top device with 66% overall performance across the alignment and clinical domains, followed by SECURE-C (58%) and Mobi-C (56%). ProDisc-C and Activ-C best maintain C2–7 lordosis. Prestige-LP best maintained the range of motion (MD 11.40°, 95% CI: 5.43–17.37). Clinical outcomes varied, with the best improvement in neck Oswestry index (NDI) for Simplify (MD: −9.40, 95% CI: −15.15 to −3.65). Meta-regression revealed significant correlations between C2 and 7 lordosis improvement and Japanese orthopedic association (JOA) scores ( t =8.446, P <0.001) and index level angle lordosis with reduced ASD ( t =5.601, P =0.030) and subsidence ( t =4.364, P =0.022). M6-C, prestige-LP, simplify, and ACDF showed a trend of better overall performance compared with other devices across parameters of sagittal alignment, preservation of motion, clinical outcomes, and adverse events, respectively. However, the recent M6-C reported complications, and the performance of SECURE-C and Mobi-C suggests that semi-constrained designs may provide a better balance, circumventing issues found in both unconstrained and constrained devices. These findings emphasize the importance of individualized device selection and long-term safety monitoring.

STUDY DESIGN:Prospective, multicenter, single-blind, randomized, controlled pivotal study. OBJECTIVE:To evaluate whether P-15L (PearlMatrix P-15 Peptide Enhanced Bone Graft) is noninferior in effectiveness to local autograft when applied in single-level instrumented transforaminal lumbar interbody fusion (TLIF). SUMMARY OF BACKGROUND DATA:P-15L, an FDA-designated Breakthrough Drug-Device, is a composite drug-device combination bone graft containing P-15, a 15-amino acid polypeptide, which enhances cell binding, proliferation, and differentiation, resulting in bone formation. MATERIALS AND METHODS:Skeletally mature patients, aged 22 to 80 years, with degenerative disc disease (DDD) were randomized 1:1 to P-15L (investigational) or to the local autograft (control) during single-level TLIF with a polyetheretherketone (PEEK) cage and supplemental pedicle screw fixation. The primary outcome was composite clinical success (CCS) at 24 months, defined as: no index level secondary surgical procedures; achievement of fusion; ≥15-point improvement in Oswestry low back pain disability questionnaire (ODI) from baseline; no new or worsening persistent neurological deficit relative to baseline; and no device-related serious adverse events (SAEs). RESULTS:A total of 290 patients were enrolled at 33 sites: 141 (48.6%) received P-15L, and 149 (51.3%) received local autograft. P-15L was noninferior ( P <0.0001) and superior ( P =0.002) to autograft with respect to CCS, with 55.5% of the investigational group achieving composite clinical success compared with 37.5% of the control group. P-15L had a 25.8% higher fusion rate as compared with autograft for the CCS at 24 months (84.3% vs. 58.5%, respectively). Device-related SAE rates were similar in both groups. CONCLUSION:P-15L was superior to local autograft in achieving clinical success at 24 months. Furthermore, P-15L produced a significantly higher fusion rate as compared with autograft. No meaningful clinical differences were found in the incidence of device-related SAEs. P-15L appears to be a safe and effective option for TLIF. LEVEL OF EVIDENCE:Level I.

Prospective, multicenter, single-blind, randomized, and controlled pivotal study. Compare time-to-fusion in patients treated with P-15L (PearlMatrix TM P-15 peptide enhanced bone graft) versus local autograft over 24 months and evaluate changes in pain and quality of life at 24 months relative to baseline. P-15L, an FDA-designated breakthrough device, is a composite bone graft with P-15, a 15-amino acid polypeptide that promotes cellular adhesion, proliferation, and differentiation to support bone formation. Patients (22–80 y) with degenerative disc disease were randomized to the investigational (P-15L) or control (local autograft) group during single-level transforaminal lumbar interbody fusion (TLIF) with a PEEK cage and supplemental pedicle screw fixation. Fusion assessments occurred at 6, 12, and 24 months. Time-to-fusion was tested for superiority as compared with the control using Kaplan-Meier survival analysis. Back and leg pain were measured using the Visual Analog Scale (VAS) and quality of life was assessed using the Short Form Survey (SF-12). The analysis included 290 patients from 33 sites; 141 (48.6%) received P-15L and 149 (51.3%) received local autograft. At randomization, at least one risk factor for pseudoarthrosis (obesity, nicotine use, or diabetes) was reported in 58.9% (83/141) of the investigational group and 60.4% (90/149) of the control group. More patients in the investigational group than the control group achieved fusion at 6 months (Kaplan-Meier fusion rates 57.6% vs. 26.9%, respectively), 12 months (68.8% vs. 41.5%, respectively), and 24 months (81.1% vs. 54.9%, respectively). P-15L was statistically superior to autograft for time-to-fusion (hazard ratio=1.87, 95% CI: 1.47–2.38; P < 0.0001). There was marked improvement in VAS and SF-12 relative to baseline in both groups at 24 months. P-15L promotes statistically superior earlier time-to-fusion than local autograft in instrumented TLIF. Both treatments resulted in clinically meaningful improvements in pain and quality of life at 24 months. Level I.

Prospective, multicenter, single-blind, randomized, controlled pivotal study. To evaluate whether P-15L (PearlMatrix P-15 Peptide Enhanced Bone Graft) is noninferior in effectiveness to local autograft when applied in single-level instrumented transforaminal lumbar interbody fusion (TLIF). P-15L, an FDA-designated Breakthrough Drug-Device, is a composite drug-device combination bone graft containing P-15, a 15-amino acid polypeptide, which enhances cell binding, proliferation, and differentiation, resulting in bone formation. Skeletally mature patients, aged 22 to 80 years, with degenerative disc disease (DDD) were randomized 1:1 to P-15L (investigational) or to the local autograft (control) during single-level TLIF with a polyetheretherketone (PEEK) cage and supplemental pedicle screw fixation. The primary outcome was composite clinical success (CCS) at 24 months, defined as: no index level secondary surgical procedures; achievement of fusion; ≥15-point improvement in Oswestry low back pain disability questionnaire (ODI) from baseline; no new or worsening persistent neurological deficit relative to baseline; and no device-related serious adverse events (SAEs). A total of 290 patients were enrolled at 33 sites: 141 (48.6%) received P-15L, and 149 (51.3%) received local autograft. P-15L was noninferior ( P <0.0001) and superior ( P =0.002) to autograft with respect to CCS, with 55.5% of the investigational group achieving composite clinical success compared with 37.5% of the control group. P-15L had a 25.8% higher fusion rate as compared with autograft for the CCS at 24 months (84.3% vs. 58.5%, respectively). Device-related SAE rates were similar in both groups. P-15L was superior to local autograft in achieving clinical success at 24 months. Furthermore, P-15L produced a significantly higher fusion rate as compared with autograft. No meaningful clinical differences were found in the incidence of device-related SAEs. P-15L appears to be a safe and effective option for TLIF. Level I.

Study DesignSystematic Review.ObjectivesCervical disc arthroplasty (CDA) is a motion-preserving alternative to fusion for degenerative cervical disc disease. Implant dislocation, though rare, can lead to severe complications. Despite growing CDA adoption, no systematic synthesis of dislocation risk factors exists, leaving clinicians without evidence-based guidelines. To our knowledge, our study is the first detailed systematic review on CDA-related implant migrations. Our study aims to synthesize literature on CDA-related migration, identify risk factors and evaluate overall management outcomes.MethodsA structured literature review was conducted, identifying 16 relevant studies through PubMed. Data were extracted on study design, patient demographics, prosthesis type, migration direction and timing, risk factors, management approaches, and clinical outcomes.ResultsAmong 40 dislocation cases, anterior migration predominated (70.0%), linked to trauma, hyperlordosis, or poor osseointegration. Posterior migration (17.5%) was associated with polyethylene wear or osteolysis. 5 cases were of unspecified direction (12.5%). 62.5% of the patients underwent revision surgery, with anterior cervical discectomy and fusion (ACDF) making up 88% of these revision surgeries. Two deaths occurred due to postoperative complications.ConclusionsCareful patient selection, optimal implant sizing, and adherence to surgical technique are critical to minimizing dislocation. Surgeons should avoid CDA in kyphotic patients and consider constrained designs in high-risk cases. Early recognition and prompt surgical intervention lead to favourable outcomes.

STUDY DESIGN:Prospective, multicenter, single-blind, randomized, and controlled pivotal study. OBJECTIVE:Compare time-to-fusion in patients treated with P-15L (PearlMatrix TM P-15 peptide enhanced bone graft) versus local autograft over 24 months and evaluate changes in pain and quality of life at 24 months relative to baseline. SUMMARY OF BACKGROUND DATA:P-15L, an FDA-designated breakthrough device, is a composite bone graft with P-15, a 15-amino acid polypeptide that promotes cellular adhesion, proliferation, and differentiation to support bone formation. METHODS:Patients (22-80 y) with degenerative disc disease were randomized to the investigational (P-15L) or control (local autograft) group during single-level transforaminal lumbar interbody fusion (TLIF) with a PEEK cage and supplemental pedicle screw fixation. Fusion assessments occurred at 6, 12, and 24 months. Time-to-fusion was tested for superiority as compared with the control using Kaplan-Meier survival analysis. Back and leg pain were measured using the Visual Analog Scale (VAS) and quality of life was assessed using the Short Form Survey (SF-12). RESULTS:The analysis included 290 patients from 33 sites; 141 (48.6%) received P-15L and 149 (51.3%) received local autograft. At randomization, at least one risk factor for pseudoarthrosis (obesity, nicotine use, or diabetes) was reported in 58.9% (83/141) of the investigational group and 60.4% (90/149) of the control group. More patients in the investigational group than the control group achieved fusion at 6 months (Kaplan-Meier fusion rates 57.6% vs. 26.9%, respectively), 12 months (68.8% vs. 41.5%, respectively), and 24 months (81.1% vs. 54.9%, respectively). P-15L was statistically superior to autograft for time-to-fusion (hazard ratio=1.87, 95% CI: 1.47-2.38; P  < 0.0001). There was marked improvement in VAS and SF-12 relative to baseline in both groups at 24 months. CONCLUSION:P-15L promotes statistically superior earlier time-to-fusion than local autograft in instrumented TLIF. Both treatments resulted in clinically meaningful improvements in pain and quality of life at 24 months. LEVEL OF EVIDENCE:Level I.

BACKGROUND: Previous analyses of the US Food and Drug Administration (FDA) Investigational Device Exemption study demonstrated the superiority of i-FACTOR compared with local autograft bone in single-level anterior cervical discectomy and fusion (ACDF) at 12 and 24 months postoperatively in a composite end point of overall success. OBJECTIVE: To report the final, 6-year clinical and radiological outcomes of the FDA postapproval study. METHODS: Of the original 319 subjects enrolled in the Investigational Device Exemption study, 220 participated in the postapproval study (106 i-FACTOR and 114 control). RESULTS: The study met statistical noninferiority success for all 4 coprimary end points. Radiographic fusion was achieved in 99% (103/104) and 98.2% (109/111) in i-FACTOR and local autograft subjects, mean Neck Disability Index improvement from baseline was 28.6 (24.8, 32.3) in the i-FACTOR and 29.2 (25.6, 32.9) in the control group, respectively (noninferiority P < .0001). The neurological success rate at 6 years was 95.9% (70/73) in i-FACTOR subjects and 93.7% (70/75) in local autograft subjects (noninferiority P < .0001). Safety outcomes were similar between the 2 groups. Secondary surgery on the same or different cervical levels occurred in 20/106 (18.9%) i-FACTOR subjects and 23/114 (20.2%) local autograft subjects (P = .866). Secondary outcomes (pain, SF-36 physical component score and mental component score) in i-FACTOR subjects were similar to those in local autograft subjects. CONCLUSION: i-FACTOR met all 4 FDA-mandated noninferiority success criteria and demonstrated safety and efficacy in single-level anterior cervical discectomy and fusion for cervical radiculopathy through 6 years postoperatively. Safety outcomes are acceptable, and the clinical and functional outcomes observed at 12 and 24 months remained at 72 months.

Study Design: Secondary analysis of data from the multicenter, randomized, parallel-controlled Food and Drug Administration (FDA) investigational device exemption study. Objective: Studies on outcomes following anterior cervical discectomy and fusion (ACDF) in individuals with diabetes are scarce. We compared 24-month radiological and clinical outcomes in individuals with and without diabetes undergoing single-level ACDF with either i-FACTOR or local autologous bone. Methods: Between 2006 and 2013, 319 individuals with single-level degenerative disc disease (DDD) and no previous fusion at the index level underwent ACDF. The presence of diabetes determined the 2 cohorts. Data collected included radiological fusion evaluation, neurological outcomes, Neck Disability Index (NDI), Visual Analog Scale (VAS) scores, and the 36-Item Short Form Survey Version 2 (SF-36v2) Physical and Mental component summary scores. Results: There were 35 individuals with diabetes (11.1%; average body mass index [BMI] = 32.99 kg/m2; SD = 5.72) and 284 without (average BMI = 28.32 kg/m2; SD = 5.67). The number of nondiabetic smokers was significantly higher than diabetic smokers: 73 (25.70%) and 3 (8.57%), respectively. Preoperative scores of NDI, VAS arm pain, and SF-36v2 were similar between the diabetic and nondiabetic participants at baseline; however, VAS neck pain differed significantly between the cohorts at baseline ( P = .0089). Maximum improvement for NDI, VAS neck and arm pain, and SF-36v2 PCS and MCS scores was seen at 6 months in both cohorts and remained stable until 24 months. Conclusions: ACDF is effective for cervical radiculopathy in patients with diabetes. Diabetes is not a contraindication for patients requiring single-level surgery for cervical DDD.

BACKGROUND i-Factor™ Bone Graft (Cerapedics Inc, Westminster, Colorado) is a composite bone substitute material consisting of P-15 synthetic collagen fragment adsorbed onto anorganic bone mineral suspended in an inert biocompatible hydrogel carrier. A pivotal, noninferiority, US FDA Investigational Device Exemption study demonstrated the benefits of i-Factor™ compared to local autograft bone in single-level anterior cervical discectomy and fusion at 1-yr postoperative. OBJECTIVE To report 2-yr follow-up. METHODS Subjects randomly received either autograft (n = 154) or i-Factor™ (n = 165) in a cortical ring allograft and followed using radiological, clinical, and patient-reported outcomes. RESULTS At 2 yr, the fusion rate was 97.30% and 94.44% in i-Factor™ and autograft subjects, respectively (P = .2513), and neurological success rate was 94.87% (i-Factor™) and 93.79% (autograft; P = .7869). Neck Disability Index improved 28.30 (i-Factor™) and 26.95 (autograft; P = .1448); Visual Analog Scale arm pain improved 5.43 (i-Factor™) and 4.97 (autograft) (p = .2763); Visual Analog Scale neck pain improved 4.78 (i-Factor™) and 4.41 (autograft; P = .1652), Short Form-36 (SF-36v2) Physical Component Score improved 10.23 (i-Factor™) and 10.18 (autograft; P = .4507), and SF36v2 Mental Component Score improved 7.88 (i-FactorTM) and 7.53 (autograft; P = .9872). The composite endpoint of overall success (fusion, Neck Disability Index improvement >15, neurological success, and absence of re-operations) was greater in i-Factor™ subjects compared to autograft subjects (69.83% and 56.35%, respectively, P = .0302). Twelve (7.45%) i-Factor™ subjects and 16 (10.53%) autograft subjects underwent re-operation (P = .3411). There were no allergic reactions associated with i-Factor™. CONCLUSION Use of i-Factor™ in anterior cervical discectomy and fusion is effective and safe, and results in similar outcomes compared to local autograft bone at 2 yr following surgery.

Background Context Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness. Purpose The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions. Study Design/Setting This is a multicenter international prospective cohort study. Patient Sample This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine. Outcome Measures The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade. Materials and Methods The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America. Results Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p<.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe. Conclusions Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM.

Study Design. A prospective, randomized, controlled, parallel, single-blinded noninferiority multicenter pivotal FDA IDE trial.Objective. The objective of this study was to investigate efficacy and safety of i-Factor Bone Graft (i-Factor) compared with local autograft in single-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy.Summary of Background Data. i-Factor is a composite bone substitute material consisting of the P-15 synthetic collagen fragment adsorbed onto anorganic bone mineral and suspended in an inert biocompatible hydrogel carrier. P-15 has demonstrated bone healing efficacy in dental, orthopedic, and nonhuman applications.Methods. Patients randomly received either autograft (N = 154) or i-Factor (N = 165) in a cortical ring allograft. Study success was defined as noninferiority in fusion, Neck Disability Index (NDI), and Neurological Success endpoints, and similar adverse events profile at 12 months.Results. At 12 months (follow-up rate 87%), both i-Factor and autograft subjects demonstrated a high fusion rate (88.97% and 85.82%, respectively, noninferiority P = 0.0004), significant improvements in NDI (28.75 and 27.40, respectively, noninferiority P<0.0001), and high Neurological Success rate (93.71% and 93.01%, respectively, noninferiority P<0.0001). There was no difference in the rate of adverse events (83.64% and 82.47% in the i-Factor and autograft groups, respectively, P = 0.8814). Overall success rate consisting of fusion, NDI, Neurological Success and Safety Success was higher in i-Factor subjects than in autograft subjects (68.75% and 56.94%, respectively, P = 0.0382). Improvements in VAS pain and SF-36v2 scores were clinically relevant and similar between the groups. A high proportion of patients reported good or excellent Odom outcomes (81.4% in both groups).Conclusion. i-Factor has met all four FDA mandated noninferiority success criteria and has demonstrated safety and efficacy in single-level ACDF for cervical radiculopathy. i-Factor and autograft groups demonstrated significant postsurgical improvement and high fusion rates.

Study Design A narrative review of literature.Objective This manuscript intends to provide a review of clinically relevant bone substitutes and bone expanders for spinal surgery in terms of efficacy and associated clinical outcomes, as reported in contemporary spine literature.Summary of Background Data Ever since the introduction of allograft as a substitute for autologous bone in spinal surgery, a sea of literature has surfaced, evaluating both established and newly emerging fusion alternatives. An understanding of the available fusion options and an organized evidence-based approach to their use in spine surgery is essential for achieving optimal results.Methods A Medline search of English language literature published through March 2016 discussing bone graft substitutes and fusion extenders was performed. All clinical studies reporting radiological and/or patient outcomes following the use of bone substitutes were reviewed under the broad categories of Allografts, Demineralized Bone Matrices (DBM), Ceramics, Bone Morphogenic proteins (BMPs), Autologous growth factors (AGFs), Stem cell products and Synthetic Peptides. These were further grouped depending on their application in lumbar and cervical spine surgeries, deformity correction or other miscellaneous procedures viz. trauma, infection or tumors; wherever data was forthcoming. Studies in animal populations and experimental in vitro studies were excluded. Primary endpoints were radiological fusion rates and successful clinical outcomes.Results A total of 181 clinical studies were found suitable to be included in the review. More than a third of the published articles (62 studies, 34.25%) focused on BMP. Ceramics (40 studies) and Allografts (39 studies) were the other two highly published groups of bone substitutes. Highest radiographic fusion rates were observed with BMPs, followed by allograft and DBM. There were no significant differences in the reported clinical outcomes across all classes of bone substitutes.Conclusions There is a clear publication bias in the literature, mostly favoring BMP. Based on the available data, BMP is however associated with the highest radiographic fusion rate. Allograft is also very well corroborated in the literature. The use of DBM as a bone expander to augment autograft is supported, especially in the lumbar spine. Ceramics are also utilized as bone graft extenders and results are generally supportive, although limited. The use of autologous growth factors is not substantiated at this time. Cell matrix or stem cell-based products and the synthetic peptides have inadequate data. More comparative studies are needed to evaluate the efficacy of bone graft substitutes overall.

BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is usually performed using iliac crest autograft, local autograft, synthetic grafts, demineralized bone, ceramics, calcium phosphates, and bone morphogenetic proteins. Local autograft bone may be of insufficient volume or uncertain quality. P-15 is a novel, synthetic, 15-amino acid polypeptide that mimics the cell-binding domain of Type I collagen and can signal a mechanical and biochemical communication pathway ultimately resulting in new bone formation. i-FactorTM Peptide Enhanced Bone Graft (Cerapedics, Inc., Westminster, CO) (i-Factor) is a composite bone substitute material of P-15 adsorbed onto anorganic bone mineral and suspended in an inert biocompatible hydrogel carrier. i-Factor is FDA-approved for single-level ACDF from C3-C7.

Study Design A narrative review of literature. Objective This manuscript intends to provide a review of clinically relevant bone substitutes and bone expanders for spinal surgery in terms of efficacy and associated clinical outcomes, as reported in contemporary spine literature. Summary of Background Data Ever since the introduction of allograft as a substitute for autologous bone in spinal surgery, a sea of literature has surfaced, evaluating both established and newly emerging fusion alternatives. An understanding of the available fusion options and an organized evidence-based approach to their use in spine surgery is essential for achieving optimal results. Methods A Medline search of English language literature published through March 2016 discussing bone graft substitutes and fusion extenders was performed. All clinical studies reporting radiological and/or patient outcomes following the use of bone substitutes were reviewed under the broad categories of Allografts, Demineralized Bone Matrices (DBM), Ceramics, Bone Morphogenic proteins (BMPs), Autologous growth factors (AGFs), Stem cell products and Synthetic Peptides. These were further grouped depending on their application in lumbar and cervical spine surgeries, deformity correction or other miscellaneous procedures viz. trauma, infection or tumors; wherever data was forthcoming. Studies in animal populations and experimental in vitro studies were excluded. Primary endpoints were radiological fusion rates and successful clinical outcomes. Results A total of 181 clinical studies were found suitable to be included in the review. More than a third of the published articles (62 studies, 34.25%) focused on BMP. Ceramics (40 studies) and Allografts (39 studies) were the other two highly published groups of bone substitutes. Highest radiographic fusion rates were observed with BMPs, followed by allograft and DBM. There were no significant differences in the reported clinical outcomes across all classes of bone substitutes. Conclusions There is a clear publication bias in the literature, mostly favoring BMP. Based on the available data, BMP is however associated with the highest radiographic fusion rate. Allograft is also very well corroborated in the literature. The use of DBM as a bone expander to augment autograft is supported, especially in the lumbar spine. Ceramics are also utilized as bone graft extenders and results are generally supportive, although limited. The use of autologous growth factors is not substantiated at this time. Cell matrix or stem cell-based products and the synthetic peptides have inadequate data. More comparative studies are needed to evaluate the efficacy of bone graft substitutes overall.

P-15 putty is a composite bone material consisting of a synthetic peptide (P-15) absorbed onto an organic bone mineral (ABM). The P-15 fragment is a short chain peptide that mimics a cell binding domain of Type I collagen that facilitates cell attraction and attachment on the ABM scaffold. P-15 putty is intended for anterior interbody spinal fusion procedures in patients with degenerative disc disease.

Development of symptomatic adjacent level degeneration (ALD) following anterior cervical discectomy and fusion (ACDF) remains a clinical concern. Cervical artificial disc replacement (C-ADR) maintains motion at the surgical level, and has been demonstrated to lower the incidence of developing radiographic ALD (R-ALD) than following ACDF.

BACKGROUND:In patients with single-level cervical degenerative disc disease, total disc arthroplasty can relieve radicular pain and preserve functional motion between two vertebrae. We compared the efficacy and safety of cervical total disc arthroplasty with that of anterior cervical discectomy and fusion (ACDF) for the treatment of single-level cervical degenerative disc disease between C3-C4 and C6-C7. METHODS:Two hundred and nine patients at thirteen sites were randomly treated with either total disc arthroplasty with ProDisc-C (n = 103) or with ACDF (n = 106). Patients were assessed preoperatively; at six weeks and three, six, twelve, eighteen, and twenty-four months postoperatively; and then annually until seven years postoperatively. Outcome measures included the Neck Disability Index (NDI), the Short Form-36 (SF-36), postoperative neurologic parameters, secondary surgical procedures, adverse events, neck and arm pain, and satisfaction scores. RESULTS:At seven years, the overall follow-up rate was 92% (152 of 165). There were no significant differences in demographic factors, follow-up rate, or patient-reported outcomes between groups. Both procedures were effective in reducing neck and arm pain and improving and maintaining function and health-related quality of life. Neurologic status was improved or maintained in 88% and 89% of the patients in the ProDisc-C and ACDF groups, respectively. After seven years of follow-up, thirty secondary surgical procedures had been performed in nineteen (18%) of 106 patients in the ACDF group compared with seven secondary surgical procedures in seven (7%) of 103 patients in the ProDisc-C group (p = 0.0099). There were no significant differences in the rates of any device-related adverse events between the groups. CONCLUSIONS:Total disc arthroplasty with ProDisc-C is a safe and effective surgical treatment of single-level symptomatic cervical degenerative disc disease. Clinical outcomes after total disc arthroplasty with ProDisc-C were similar to those after ACDF. Patients treated with ProDisc-C had a lower probability of subsequent surgery, suggesting that total disc arthroplasty provides durable results and has the potential to slow the rate of adjacent-level disease. LEVEL OF EVIDENCE:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND CONTEXT: Cervical spondylotic myelopathy (CSM) is a chronic spinal cord disease and can lead to progressive or stepwise neurologic decline. Several factors may influence this process, including extent of spinal cord compression, duration of symptoms, and medical comorbidities. Diabetes is a systemic disease that can impact multiple organ systems, including the central and peripheral nervous systems. There has been little information regarding the effect of diabetes on patients with coexistent CSM.PURPOSE: To provide empirical data regarding the effect of diabetes on treatment outcomes in patients who underwent surgical decompression for coexistent CSM.STUDY DESIGN/SETTING: Large prospective multicenter cohort study of patients with and without diabetes who underwent decompressive surgery for CSM.PATIENT SAMPLE: Two hundred thirty-six patients without and 42 patients with diabetes were enrolled. Of these, 37 were mild cases and five were moderate cases. Four required insulin. There were no severe cases associated with end-organ damage.OUTCOME MEASURES: Self-report measures include Neck Disability Index and version 2 of 36-Item Short Form Health Survey (SF-36v2), and functional measures include modified Japanese Orthopedic Association (mJOA) score and Nurick grade.METHODS: We compared presurgery symptoms and treatment outcomes between patients with and without diabetes using univariate and multivariate models, adjusting for demographics and comorbidities.RESULTS: Diabetic patients were older, less likely to smoke, and more likely to be on social security disability insurance. Patients with diabetes presented with a worse Nurick grade, but there were no differences in mJOA and SF-36v2 at presentation. Overall, there was a significant improvement in all outcome parameters at 12 and 24 months. There was no difference in the level of improvement between the patients with and without diabetes, except in the SF-36v2 Physical Functioning, in which diabetic patients experienced significantly less improvement. There were no differences in surgical complication rates between diabetic patients and nondiabetic patients.CONCLUSIONS: Except for a worse Nurick grade, diabetes does not seem to affect severity of symptoms at presentation for surgery. More importantly, with the exception of the SF-36v2 Physical Functioning scores, outcomes of surgical treatment are similar in patients with diabetes and without diabetes. Surgical decompression is effective and should be offered to patients with diabetes who have symptomatic CSM and are appropriate surgical candidates. (C) 2014 Elsevier Inc. All rights reserved.

BACKGROUND:Cervical spondylotic myelopathy is the leading cause of spinal cord dysfunction worldwide. The objective of this study was to evaluate the impact of surgical decompression on functional, quality-of-life, and disability outcomes at one year after surgery in a large cohort of patients with this condition. METHODS:Adult patients with symptomatic cervical spondylotic myelopathy and magnetic resonance imaging evidence of spinal cord compression were enrolled at twelve North American centers from 2005 to 2007. At enrollment, the myelopathy was categorized as mild (modified Japanese Orthopaedic Association [mJOA] score ≥ 15), moderate (mJOA = 12 to 14), or severe (mJOA < 12). Patients were followed prospectively for one year, at which point the outcomes of interest included the mJOA score, Nurick grade, Neck Disability Index (NDI), and Short Form-36 version 2 (SF-36v2). All outcomes at one year were compared with the preoperative values with use of univariate paired statistics. Outcomes were also compared among the severity classes with use of one-way analysis of variance. Finally, a multivariate analysis that adjusted for baseline differences among the severity groups was performed. Treatment-related complication data were collected and the overall complication rate was calculated. RESULTS:Eighty-five (30.6%) of the 278 enrolled patients had mild cervical spondylotic myelopathy, 110 (39.6%) had moderate disease, and 83 (29.9%) had severe disease preoperatively. One-year follow-up data were available for 222 (85.4%) of 260 patients. There was a significant improvement from baseline to one year postoperatively (p < 0.05) in the mJOA score, Nurick grade, NDI score, and all SF-36v2 health dimensions (including the mental and physical health composite scores) except general health. With the exception of the change in the mJOA, the degree of improvement did not depend on the severity of the preoperative symptoms. These results remained unchanged after adjusting for relevant confounders in the multivariate analysis. Fifty-two patients experienced complications (prevalence, 18.7%), with no significant differences among the severity groups. CONCLUSIONS:Surgical decompression for the treatment of cervical spondylotic myelopathy was associated with improvement in functional, disability-related, and quality-of-life outcomes at one year of follow-up for all disease severity categories. Furthermore, complication rates observed in the study were commensurate with those in previously reported cervical spondylotic myelopathy series.