Search Results (79)

Background/Objectives: Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) can produce comparable short-term clinical outcomes, but their regional effects on cervical muscle morphology are incompletely characterized. This study compared 12-month clinical outcomes and quantitative magnetic resonance imaging (MRI) changes after single-level C6–7 ACDF and CDA. Methods: This retrospective longitudinal cohort included 100 age-, sex-, and body mass index-matched patients (50 ACDF and 50 CDA). Neck and arm pain were assessed on 0–10 scales, and the Neck Disability Index (NDI) was analyzed as a 0–50-point score. Regional muscle cross-sectional area (CSA) and fatty infiltration (FI) were quantified on standardized preoperative and 12-month axial T2-weighted turbo spin-echo images at C6–7. The primary analysis included four posterior muscles. CSA change was expressed relative to baseline, whereas FI change was expressed in percentage points. Results: Clinical outcomes were statistically indistinguishable at 12 months (neck-pain score, 0.50 vs. 0.36, p = 0.318; NDI, 2.6 vs. 2.2 points, p = 0.479; perfect-outcome rate, 68.0% in both groups). Both groups showed significant regional posterior muscle CSA reduction and FI increase; however, the magnitude was greater after ACDF than after CDA (CSA reduction, −15% to −19% vs. −5% to −9%; absolute FI increase, +5.1 to +8.2 vs. +1.1 to +2.3 percentage points; all between-group q < 0.001). Surgical technique was independently associated with both MRI change metrics. Greater regional CSA reduction was modestly associated with higher concurrent 12-month neck-pain scores (β = −0.26, p = 0.022). This concurrent association does not establish causation or predict outcomes beyond 12 months. Conclusions: ACDF and CDA produced equivalent measured clinical outcomes at 12 months, while CDA showed a more favorable regional posterior muscle MRI profile. Differential device-related artifact was not quantitatively assessed and cannot be completely excluded, although concordant findings across four implant-remote posterior muscles make artifact unlikely to be the sole explanation. The functional and longer-term clinical significance of this imaging difference is not established and requires prospective longitudinal study. Full article

Background/Objectives: degenerative cervical myelopathy (DCM) is the leading cause of spinal cord impairment in adults, often resulting in disability and reduced quality of life (QoL). Surgery is recommended for moderate and severe cases, while its role in mild DCM remains debated. Emerging evidence suggests that early surgery may improve outcomes, particularly QoL. Methods: We conducted a retrospective, single-center observational study of a cohort of patients undergoing cervical spine surgery for DCM between January 2020 and August 2023 at a single institution (Policlinico di Monza, Italy). Demographic, clinical, radiological and surgical data, as well as complications and outcomes, were analyzed. Neurological status was assessed using the modified Japanese Orthopedic Association (mJOA) score and QoL was evaluated using the Short Form-36 (SF-36) questionnaire preoperatively, at discharge, and at follow-up. Results: 51 patients were included (mean age 58.1 years; 41% female), with anterior surgery performed in 67%. Mild preoperative mJOA score was observed in 74% of patients. At follow-up, 65% achieved complete recovery, 29% improved, and 6% remained stable. No neurological deterioration was recorded. Univariate analysis identified age, anterior cervical discectomy and fusion (ACDF), and mild preoperative mJOA score as significant predictors of recovery. Multivariate logistic regression analysis identified mild preoperative mJOA score as a strong independent predictor of complete clinical recovery (OR = 240.64, 95% CI: 6.82–8496.22, p = 0.002). SF-36 showed significant improvements in emotional well-being, social functioning, pain, and general health, particularly in mild cases. Complications were low (5.8%) and limited to transient dysphagia. Conclusions: early surgical treatment in selected patients with mild DCM may be associated with favorable neurological and quality-of-life outcomes, although larger prospective studies are needed. Full article

Background: Three-level anterior cervical discectomy and fusion (ACDF) is widely used for multilevel cervical degenerative disc disease; however, the relationship between postoperative alignment trajectories, adjacent segment degeneration (ASD), and late patient-reported outcomes remains incompletely defined. This study evaluated plane-specific radiological alignment changes, MRI-based ASD, and late functional outcomes in a homogeneous three-level ACDF cohort. Methods: This single-center observational cohort included 29 patients who underwent three-level ACDF between January 2018 and December 2023 and had complete radiographic follow-up. Radiological data were collected retrospectively from institutional records and imaging archives. Cervical sagittal and coronal alignment were assessed using Cobb angles on radiographs obtained preoperatively and at 6 months, 1 year, and 2 years postoperatively. ASD was evaluated at the superior adjacent segment on 2-year MRI. Late patient-reported clinical outcomes were assessed at a mean follow-up of 42.6 ± 6.8 months using the Visual Analog Scale (VAS), Neck Disability Index (NDI), and Nottingham Health Profile (NHP). Results: Sagittal Cobb angle changed significantly over time (χ²(3) = 12.60, p = 0.006; Kendall’s W = 0.145), whereas coronal Cobb angle showed a statistically significant reduction over time, although the absolute magnitude of change was small (χ²(3) = 28.74, p < 0.001; Kendall’s W = 0.330). Lower sagittal Cobb angle correlated with worse NDI (r = −0.46, p = 0.004), and greater coronal Cobb angle correlated with worse physical activity scores (r = 0.52, p = 0.006). Higher Pfirrmann grade correlated with worse NDI (r = 0.49, p = 0.004) and pain scores (r = 0.44, p = 0.021). In exploratory regression analysis, sagittal Cobb angle and Pfirrmann grade were retained in the model for NDI, but these findings should be interpreted as hypothesis-generating. Conclusions: After three-level ACDF, sagittal and coronal alignment followed different postoperative trajectories. Lower sagittal alignment and greater adjacent disc degeneration were associated with worse late neck-related disability. However, given the modest sample size and exploratory nature of the regression analysis, these findings should be interpreted as hypothesis-generating. Larger prospective studies are needed to confirm whether sagittal alignment and MRI-based adjacent segment degeneration independently contribute to late functional outcomes. Full article

Background and Objectives: Postoperative dysphagia following anterior cervical discectomy and fusion (ACDF) remains a common complication affecting patient quality of life. This study evaluated the safety and clinical efficacy of reprocessed micronized acellular dermal matrix (ADM) compared to conventional gel-type anti-adhesive agents in patients undergoing single-level ACDF. Materials and Methods: This retrospective propensity score-matched study included 108 patients (54 matched pairs) who underwent single-level ACDF between January 2021 and December 2025. The ADM group received CGDerm Matrix™ and the control group received Mediclore™. The primary outcome was postoperative swallowing function assessed by the Swallowing Impairment Score (SIS-6) at 3 months (pre-specified primary time point). Secondary outcomes included VAS, NDI, modified MacNab criteria, adhesion scores, prevertebral soft tissue swelling, and perioperative inflammatory markers. Bonferroni correction was applied for multiple comparisons (adjusted α = 0.0125). Results: The ADM group demonstrated significantly lower SIS-6 scores at 3 months (0.26 ± 0.16 vs. 0.68 ± 0.27, p = 0.01), which remained significant after Bonferroni correction. All other clinical and radiological outcomes were comparable between groups. No device-related complications occurred. Conclusions: ADM application in ACDF surgery appears safe and is associated with improved postoperative swallowing function at 3 months. However, the clinical significance of observed differences requires further investigation. Full article

Background/Objectives: i-Factor™ Bone Graft is a composite bone substitute containing P-15 synthetic collagen fragment that has demonstrated noninferiority to local autograft in single-level anterior cervical discectomy and fusion (ACDF); however, direct head-to-head comparisons with demineralized bone matrix (DBM) using contemporary 3D-printed titanium cages are lacking. The aim of this retrospective study was to compare radiographic fusion rates, segmental stability, and clinical outcomes between i-Factor™ and DBM in single-level ACDF, with a particular focus on the early time course of fusion. Methods: A retrospective propensity score-matched cohort study was conducted in patients with single-level cervical degenerative disc disease (cervical disc herniation, cervical spondylotic radiculopathy, or cervical spondylotic myelopathy) operated between December 2021 and January 2024 at a single tertiary care hospital. Seventy-six consecutive patients undergoing single-level ACDF with 3D-printed titanium cages were matched 1:1 (i-Factor™ vs. DBM) on age, sex, and operative level. Fusion status was assessed by serial dynamic radiographs at 1, 3, 6, and 12 months and by 3D-CT at 12 months in all patients (with additional CT at earlier timepoints when plain films were equivocal), by two independent spine surgeons blinded to graft type; inter-rater agreement (Cohen’s κ) was computed. Results: Mean follow-up was 18.1 months. Fusion rates for i-Factor™ at 3, 6, and 12 months were 94.7%, 100%, and 100%, respectively, compared to 71.1%, 84.2%, and 94.7% for DBM. The differences were statistically significant at 3 months (p = 0.047) and 6 months (p = 0.012), but not at 12 months (p = 0.493). Inter-rater agreement was almost perfect (κ = 0.86–1.00). No adverse reactions or device-related complications were observed. Conclusions: In this matched cohort, i-Factor™ was associated with significantly faster fusion than DBM in single-level ACDF, with similar 12-month fusion rates. No adverse reactions were observed, although the sample size is insufficient to exclude rare complications. Full article

Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed surgical procedures for the treatment of cervical degenerative disease, myelopathy, radiculopathy, and segmental instability. Although clinical outcomes are generally favorable, pseudarthrosis remains a relevant complication, with a reported incidence ranging from 5% to 20%. In a field with no yet clear main directions, this narrative review aims at giving the reader a broad picture and a wide analysis of the recent advances in cervical spinal fusion, with particular focus on biomaterials, intervertebral cage technologies, cervical spine biomechanics and imaging methods used for fusion assessment. The literature regarding quantitative imaging parameters and emerging applications of artificial intelligence (AI) is also reviewed. Current bone grafts include autologous grafts, allografts, xenografts and polymeric grafts, while the materials for the intervertebral cages comprehend titanium, polyetheretherketone and silicon nitride, with reported fusion rates distributed in a very large range. Computed tomography (CT) remains the standard imaging modality to assess whether fusion has occurred, due to its high spatial resolution. However, the lack of shared diagnostic criteria and the significant interobserver variability continue to limit its reliability. Quantitative parameters, such as Hounsfield Unit measurements and MRI-derived bone quality scores, may contribute to a more objective evaluation, although current evidence remains heterogeneous. In parallel, AI-based imaging analysis is showing promising results for quantitative assessment and longitudinal monitoring of bone fusion; however, large prospective clinical studies are still needed to confirm its clinical applicability. In conclusion, despite advances in surgical technologies and biomaterials, radiological assessment of cervical fusion still lacks universally accepted diagnostic standards. Future AI applications may improve diagnostic accuracy and reproducibility, promoting a more standardized approach in clinical practice. Full article

Finite element analysis is widely used to study spinal biomechanics and to compare surgical strategies under controlled loading conditions. By allowing variation in alignment, fixation, and implant design, these models provide insight into stress redistribution and motion changes that are difficult to isolate experimentally. This review examines spine surgery-focused finite element studies published between 2018 and 2024, with emphasis on interbody fusion techniques, adjacent segment mechanics, and implant-related stress behavior. Across lumbar fusion models, constructs incorporating anterior column support demonstrate lower posterior instrumentation stress than posterior-only approaches, with lateral lumbar interbody techniques showing reduced rod and screw stresses across multiple loading conditions compared with posterior lumbar interbody or posterolateral fusion constructs. In the cervical spine, comparisons of plated and zero-profile anterior cervical discectomy and fusion devices show smaller increases in adjacent-level motion and intradiscal pressure with zero-profile constructs, alongside higher localized stress at fixation interfaces. More recent studies apply finite element methods to implant optimization, alignment planning, and patient-specific modeling. Together, these findings suggest that finite element analysis is increasingly used to support surgical planning and implant design, with continued advances in validation and patient-specific simulation likely to strengthen its clinical relevance. Full article

Cervical spondylosis is a common cause of spinal cord dysfunction, and anterior cervical discectomy and fusion (ACDF) is widely employed when conservative treatment fails. Conventional implant systems such as the cervical cage with plate (CCP) and zero-profile stand-alone cage (ZPSC) are commonly used to enhance spinal stability and promote fusion, but they are associated with complications including dysphagia and adjacent segment degeneration. To address these limitations, a novel flexible plate cage system (FPCS) has been developed to optimize biomechanical performance while minimizing surgical risk. In this study, a finite element model of the C3–T1 cervical spine was constructed to simulate ACDF at the C5–C6 level using CCP, ZPSC, and FPCS implants. Under standardized loading conditions, von Mises stress was analyzed in the bone, intervertebral disc, endplates, cage, and screws, using the mean of the top 5% stress values to ensure accuracy. All surgical models showed increased stress compared to the intact reference spine. The ZPSC model exhibited the highest stress in the cage and screws, suggesting a more concentrated load path. The CCP model showed a more evenly distributed stress profile, particularly affecting the inferior adjacent segment. The FPCS model demonstrated moderate cage stress, reduced screw stress, and the highest plate stress, indicating a design that effectively redirects mechanical load from the screw-bone interface toward the anterior plate. This may be related to the unique structural configuration of the FPCS, which secures screws horizontally into the anterior vertebral body without penetrating the endplates. These findings suggest that the FPCS may offer a biomechanically favorable alternative to existing ACDF implants. Full article

Background/Objectives: Postoperative cervical spine radiographs are routinely obtained during in-hospital and follow-up period. We aim to evaluate the utility of postoperative radiographs for identifying instrumentation failure and the subsequent need for revision surgery in patients with traumatic cervical spine injuries. Materials and Methods: A retrospective chart review of patients who had surgical treatment for traumatic cervical spine injury was conducted. Clinical notes and radiographic reports were evaluated. Postoperative radiographs were obtained prior to discharge from the hospital, and subsequently at 2, 6, 12, 24 weeks, and 1 year. Patients who underwent revision surgery, described as any reoperation, were identified. The patients’ indications for surgery were evaluated. The results of postoperative radiographs that prompted a change in management and reoperation were analyzed. Sensitivity and specificity for postoperative radiographs were calculated. Results: A total of 295 patients were reviewed. The rate of revision surgery was 3.7% (n = 11). All 11 patients presented changes in clinical findings and physical exam, but only 3 patients (1%) were identified to have undergone revision surgery due to instrumentation failure seen on radiographs at 13, 89, and 112 days postoperatively, and none within the inpatient period. Two patients underwent revision surgery due to epidural hematoma, and six patients due to wound infection. The overall sensitivity and specificity of routine postoperative radiographs were 27% and 100%, respectively. Conclusions: Postoperative radiographs after cervical spine trauma have low clinical utility for predicting instrumentation failure in the absence of clinical findings, particularly in the inpatient period. Full article

Background/Objectives: Degenerative cervical myelopathy (DCM) may result from posture-dependent spinal cord compromise not detectable on neutral imaging. Dynamic MRI can uncover clinically relevant mechanisms underlying otherwise unexplained myelopathy and guide management. This report illustrates a dynamic cervical myelopathy phenotype revealed by flexion–extension imaging and its impact on surgical decision-making. Methods: A 49-year-old man presented with progressive bilateral upper-limb paresthesias, intrinsic hand atrophy, and distal weakness. Neutral cervical MRI, standard radiographs, and flexion–extension MRI were performed to investigate a suspected dynamic etiology, including differentiation from Hirayama disease. Surgical treatment consisted of anterior cervical discectomy and fusion (ACDF), with clinical and radiological follow-up. Results: Neutral MRI showed intramedullary T2 hyperintensity from C4 to C6 without static canal stenosis or frank compression, while radiographs demonstrated segmental kyphosis without instability. Flexion MRI revealed reproducible spinal cord contact with a small cranially located osteophyte at C5–C6, concordant with the myelopathic signal. ACDF at C4–C6 led to clinical improvement. One year later, recurrent symptoms from adjacent-segment pathology (C3–C4 myelopathic signal and C6–C7 foraminal disc herniation) required a second ACDF, resulting in durable neurological stability. Conclusions: This case demonstrates flexion-dependent cord–osteophyte conflict causing cervical myelomalacia in the absence of static stenosis. Dynamic MRI resolved a clinical–radiological mismatch and directly informed surgical planning. Recognition of dynamic myelopathy phenotypes and vigilance for adjacent-segment disease after fusion are essential for optimizing outcomes. Full article

Background: Anterior cervical discectomy and fusion (ACDF) is a widely performed procedure for treating degenerative cervical spine conditions. While it effectively addresses neural decompression and restores segmental alignment, the interplay of baseline alignment and implant-specific factors on postoperative segmental alignment remains underexplored. This study evaluates the influence of preoperative cervical alignment and interbody cage design on segmental alignment changes following 1- to 3-level ACDF. Methods: Following institutional review board approval, we identified 258 patients undergoing ACDF for degenerative pathology between 1 January 2010 and 31 December 2023. Preoperative and postoperative radiographs were analyzed for cervical alignment, disc height, and segmental lordosis. Cage dimensions, lordosis, and positioning relative to vertebral landmarks were recorded. Multivariable linear regression models evaluated predictors of postoperative disc height, segmental lordosis, and their respective changes. Results: Postoperative disc height was positively associated with greater cage height (β = 1.13 mm per mm, p < 0.001) and negatively associated with greater cage lordosis (β = −0.10 mm per °, p = 0.001). Segmental lordosis was positively influenced by cage height (β = 0.78° per mm, p = 0.002) and lordosis (β = 0.42° per °, p = 0.002) but was negatively correlated with the distance of the cage from the anterior edge of the cranial vertebra (β = −1.76° per mm, p = 0.004). Greater preoperative segmental kyphosis predicted more significant postoperative lordosis correction (β = −1.07° per °, p < 0.001). Conclusions: This study underscores the importance of preoperative alignment and interbody cage design in achieving optimal segmental correction following ACDF. While cage height primarily drives disc height restoration, surgical technique, particularly anterior placement of the cage, is pivotal for enhancing segmental lordosis. These findings support personalized surgical planning to optimize alignment and patient outcomes. Full article

Background: Anterior cervical discectomy and fusion (ACDF) is widely performed and has a low incidence of postoperative infection. Anterior cervical abscess is a rare but potentially life-threatening complication, typically caused by skin or oral flora. Identification of atypical pathogens has important implications for diagnostic vigilance and antimicrobial management. Case Presentation: We report a 56-year-old man with degenerative cervical myelopathy and significant respiratory comorbidity who underwent single-level ACDF and developed progressive dysphagia and neck pain in the early postoperative period. Imaging demonstrated a prevertebral abscess requiring urgent surgical drainage. Intraoperative cultures identified Moraxella catarrhalis, a respiratory tract commensal rarely implicated in postoperative spinal infections. No evidence of esophageal perforation or superficial wound contamination was identified. The patient was treated with surgical washout and prolonged culture-directed antibiotic therapy, with full clinical recovery. To contextualize novelty, we performed a focused review of the available literature on M. catarrhalis spinal infections. Conclusions: This case expands the spectrum of pathogens implicated in postoperative cervical spine infections and highlights the need to consider respiratory tract organisms in high-risk patients, particularly those with chronic pulmonary disease or immunosuppression. Early imaging in the presence of dysphagia, prompt source control, and culture-directed antimicrobial therapy are essential to optimizing outcomes. Full article

Background/Objectives: To evaluate the clinical and radiological outcomes of surgical interventions stratified by dynamic K-line status and to identify predictors of neurological recovery in multilevel cervical ossification of the posterior longitudinal ligament (OPLL). Methods: This study analyzed 535 patients with multilevel cervical OPLL who underwent anterior cervical discectomy and fusion (ACDF), laminoplasty (LP), or laminectomy with fusion (LF), with a minimum 24 months of follow-up. Patients were classified based on dynamic K-line status—neutral (NK-line) and flexion (FK-line)—into three groups: Group 1 (NK-line [+]/FK-line [+]), Group 2 (NK-line [+]/FK-line [−]), and Group 3 (NK-line [−]/FK-line [−]). Radiographic parameters, JOA scores, and VAS were compared, and multivariate regression identified predictors of recovery. A multinomial inverse probability of treatment weighting (IPTW) analysis was conducted to reduce treatment selection bias. Results: Progressive dynamic K-line negativity was associated with greater cervical kyphosis, a higher canal-occupying ratio, reduced FK-line distance, and poorer neurological recovery. After IPTW analysis, ACDF showed higher adjusted recovery across subgroups. In Group 1, younger age and fewer operative levels predicted better recovery. In Groups 2 and 3, LF demonstrated significantly greater neurological recovery than LP. A larger preoperative FK-line distance and a greater postoperative FK-line distance increase were independent predictors of favorable outcomes. Conclusions: Dynamic K-line stratification has good prognostic value in multilevel cervical OPLL. ACDF remains the most effective procedure across dynamic K-line status groups, and LF is preferred over LP in patients with latent or fixed FK-line (−). Incorporating dynamic K-line metrics into surgical planning could improve procedure selection and enhance neurological recovery. Full article

Dural tear (DT) and cerebrospinal fluid (CSF) leakage, though uncommon complications, represent a potentially serious risk of anterior cervical spine surgery, particularly in patients with ossification of the posterior longitudinal ligament (OPLL). While the incidence in routine anterior cervical discectomy and fusion (ACDF) or corpectomy (ACCF) is typically below 0.5%, it rises sharply to 4–32% in OPLL cases. Furthermore, it exceeds 60% when dural ossification (DO) is present. Adhesion and ossification obliterate the normal epidural plane, creating a fragile osteofibrotic interface that is highly susceptible to tearing during decompression. This review synthesizes current evidence on the pathophysiology of DT and CSF leakage in anterior cervical spine surgery, provides a framework for risk stratification, and outlines evolving techniques for successful repair and management. Intraoperative management has shifted from direct resection toward dura-preserving floating decompression and biologically reinforced multilayer repair using fascia, collagen matrix, fibrin adhesives, and polyethylene glycol (PEG) hydrogel sealants. Postoperative care emphasizes controlled CSF pressure regulation, sterile wound management, and early ambulation. Most DTs achieve successful closure with timely recognition and standardized treatment. However, persistent leakage may require escalation to composite reconstruction, epidural blood patch, or vascularized flap reinforcement. Emerging technologies such as bioactive hydrogels, 3D-printed dural scaffolds, and artificial intelligence–assisted imaging offer potential future improvements, although clinical adoption remains limited. This review summarizes current evidence on the mechanisms, risk factors, diagnostic predictors, repair strategies, and postoperative management of DT and CSF leakage, with specific attention to OPLL-related DO. A more apparent distinction between established clinical practice and emerging investigational technologies is provided to guide evidence-based decision-making. Full article

Reconstruction of large and complex hard tissue defects remains a major clinical challenge, as conventional autografts and allografts are often limited in availability, biological compatibility, and long-term efficacy, particularly for extensive defects or poor bone quality. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a potent osteoinductive factor capable of initiating the complete cascade of bone formation. However, its clinical use is restricted by dose-dependent complications such as inflammation, ectopic ossification, and osteolysis. This review synthesizes current evidence on the safety profile of rhBMP-2 and examines strategies to enhance its therapeutic index. Preclinical and clinical data indicate that conventional collagen-based carriers frequently cause rapid burst release and uncontrolled diffusion, aggravating adverse outcomes. It is noteworthy that low doses of rhBMP-2 (0.5–0.7 mg/level in anterior cervical discectomy and fusion (ACDF) or 0.5–1.0 mg/level in transforaminal lumbar interbody fusion (TLIF)) provide the optimal balance of efficacy and safety. Advanced biomaterial-based platforms, such as bioceramic–polymer composites, injectable hydrogels, and 3D-printed scaffolds, enable spatially and temporally controlled release while maintaining osteogenic efficacy. Molecular delivery approaches, including chemically modified messenger RNA (cmRNA) and regional gene therapy, provide transient, site-specific rhBMP-2 expression with reduced dosing and minimal systemic exposure. By integrating mechanistic insights with translational advances, this review outlines a framework for optimizing rhBMP-2-based regenerative protocols, emphasizing their potential role in multidisciplinary strategies for reconstructing complex hard tissue defects. Full article