Anterior cervical intercorporal fusion in patients with osteoporotic or tumorous fractures using a cement augmented cervical plate system: first results of a prospective single-center study

Safety and Efficacy of Anterior Cervical Corpectomy and Reconstruction With Expandable Cages for Treatment of Cervical Myelopathy-Focusing on Stand-Alone Cages: A Systematic Review and Meta-Analysis

Study DesignSystematic review and Meta-analysis.ObjectivesThis study aims to evaluate the efficacy, postoperative outcomes, and potential complications of using expandable cages in cervical spine surgery.MethodsA comprehensive search was performed across Medline, Scopus, Web of Science, Cochrane, and Embase up to May 22, 2023. Meta-analyses and subgrouping analyses were performed using "OpenMetaAnalyst" and R software to analyze efficacy outcomes and complications. The assessment of heterogeneity utilized the i2 and chi-squared tests, applying the random effect model.ResultsThirty studies were included, with 22 eligible for meta-analysis. The pooled data showed a significant improvement in the Cobb angle, Nurick's score and modified Japanese Orthopedic Association (mJOA) score. The pooled stability rate post-surgery was 0.94 based on 7 studies, but the stand-alone cages showed a lower stability rate (0.83). Fusion rate showed high success at 0.94 across 14 studies but also the fusion rate in the stand-alone group was lower (0.89) with substantial heterogeneity (I2 = 91.81%) suggests that stand-alone cages may not consistently achieve the same level of fusion as cages with anterior plating (fusion rate of 0.98, I2 = 0%). Dysphagia was observed in 16% of patients, and hardware-related issues were reported in 9% of cases.Conclusionsexpandable cages offer significant advantages in terms of fusion, stability, and neurological recovery. In particular, stand-alone expandable cages were associated with higher rates of complications, including dysphagia, subsidence, and hardware failure, compared to cages with anterior plating.

MRI-Based Cervical VBQ Scores as Predictors of Cage Subsidence in Cervical Spine Surgery: A Meta-Analysis

Study DesignSystematic review and meta-analysis.ObjectivePoor bone quality is a major risk factor for complications after cervical spine surgery. The MRI-based cervical vertebral bone quality (C-VBQ) score is a reliable tool for assessing bone quality. This study systematically evaluates, for the first time, the predictive value of C-VBQ for cage subsidence risk in cervical spine surgery patients using meta-analysis.MethodsWe conducted a comprehensive search of relevant literature in electronic databases up to October 16, 2024, to systematically assess the quality of included studies. Publication bias was evaluated by comparing C-VBQ between groups and calculating pooled sensitivity, specificity, and summary receiver operating characteristic (SROC) curves.Results7 studies involving 681 patients were included. Using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool, the studies were deemed high quality with low risk of bias. High C-VBQ scores were significantly associated with fusion subsidence, with a pooled odds ratio of 2.98 (95% CI: 1.68-5.30). The C-VBQ cut-off value was 2.94 ± 0.32, and the combined sensitivity and specificity for diagnosing postoperative complications were 0.78 and 0.87, respectively, with an area under the curve of 0.90 (95% CI: 0.87-0.92).ConclusionIn patients undergoing degenerative cervical spine surgery, higher C-VBQ scores were significantly associated with an increased risk of cage subsidence. The C-VBQ score is a reliable tool for preoperative bone quality assessment and serves as an independent predictor of cage subsidence risk following cervical spine surgery.

Treatment of Ankylosing Spondylitis Patients with Cervical Spinal Injury with Anterior Single-Stage Fixation with Bone Cement Augmentation

Background/Objectives: Cervical spine fractures in ankylosing spondylitis (AS) are characterized as highly unstable fractures posing an elevated risk of neurological deficit and a significantly elevated mortality rate. This study assesses the efficacy and safety of single-stage plate stabilization with ventral cement augmentation in treating subaxial cervical spine fractures in patients with AS. Methods: Over 86 months, 38 patients diagnosed with AS received ventral plate stabilization with cement augmentation after suffering unstable subaxial cervical fractures. No additional dorsal stabilization was used in any of these surgeries. Results: There were no complications as a result of cement leakage. During the follow-up period, screw loosening and implant displacement were documented in two out of 38 cases. At the time of data analysis, 17 patients who had undergone treatment had died, representing 44.7% of the total cases. Seven patients died within 1 month, two patients died within 6 months, four patients died within 1 year, and four patients died after 1 year. Conclusions: Our study shows that a single-stage anterior screw and plate fixation of the cervical spine with cement augmentation could be a feasible and effective method to treat cervical spine fractures in patients with AS.

A Review of Strategies to Improve Biomechanical Fixation in the Cervical Spine

STUDY DESIGN

Systematic review.

OBJECTIVES

Review the surgical techniques and construct options aimed at improving the biomechanical strength of cervical constructs.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of the MEDLINE, Embase, and Cochrane Library databases was performed to identify all studies examining biomechanical strategies utilized in the osteoporotic cervical spine. Screening was performed in duplicate for all stages of the review process.

RESULTS

An initial search returned 3887 articles. After deletion of duplications and review of abstracts and full text, 39 articles met inclusion criteria. Overall, the surgical techniques reviewed aimed at obtaining rigid fixation in the setting of poor bone quality, or dispersing the forces at the bone-implant interface. We identified 6 key techniques to improve biomechanical fixation. These include bicortical fixation, appropriate screw selection (size and trajectory), PMMA augmentation, load sharing techniques, consideration of ancillary fixation around the occipitocervical junction, and supplementing the construct with post-operative collar or halo.

CONCLUSION

The summation of the literature highlights a framework of modalities available to surgeons to improve biomechanical fixation in the cervical spine. While these may improve construct strength in the setting of osteoporosis, there is a paucity of evidence available to make recommendations in this patient population.

Lumbar Intervertebral Spacer With Cement Augmentation of Endplates and Integrated Screws as a Fixation Device in an Osteoporotic Model: An In Vitro Kinematic and Load-to-Failure Study

BACKGROUND

Integrated lateral lumbar interbody fusion (LLIF) devices have been shown to successfully stabilize the spine and avoid complications related to posterior fixation. However, LLIF has increased subsidence risk in osteoporotic patients. Cement augmentation through cannulated pedicle screws enhances pedicle fixation and cage-endplate interface yet involves a posterior approach. Lateral application of cement with integrated LLIF fixation has been introduced and requires characterization. The present study set out to evaluate kinematic and load-to-failure properties of a novel cement augmentation technique with an integrated LLIF device, alone and with unilateral pedicle fixation, compared with bilateral pedicle screws and nonintegrated LLIF (BPS + S).

METHODS

Twelve specimens (L3-S1) underwent discectomy at L4-L5. Specimens were separated into 3 groups: (1) BPS + S; (2) polymethyl methacrylate (PMMA) augmentation, integrated LLIF, and unilateral pedicle screws (PMMA + UPS + iS); and (3) PMMA and integrated LLIF (PMMA + iSA) without posterior fixation. Flexion-extension, lateral bending, and axial rotation were applied. A compressive load was applied to L4-L5 segments until failure. An analysis was performed (P < .05).

RESULTS

Operative constructs significantly reduced motion relative to intact specimens in all motion planes (P < .05). BPS + S provided the most stability, reducing motion by 71.6%-86.4%, followed by PMMA + UPS + iS (68.1%-79.4%) and PMMA + iSA (62.9%-81.9%); no significant differences were found (P > .05). PMMA + UPS + iS provided the greatest resistance to failure (2290 N), followed by PMMA + iSA (1970 N) and BPS + S (1390 N); no significant differences were observed (P > .05).

CONCLUSIONS

Cement augmentation of vertebral endplates via the lateral approach with integrated LLIF moderately improved cage-endplate strength compared to BPS + S in an osteoporotic model; unilateral pedicle fixation further improved failure load. Reconstruction before and after application of unilateral pedicle screws and rods was biomechanically equivalent to anteroposterior reconstruction. Overall, initial results suggest that integrated LLIF with cement augmentation may be a viable alternative in the presence of osteoporosis.

Vertebral Body Replacement With an Anchored Expandable Titanium Cage in the Cervical Spine: A Clinical and Radiological Evaluation

BACKGROUND

Expandable cervical cages have been used successfully to reconstruct the anterior spinal column.

OBJECTIVE

To perform clinical and radiological evaluation of vertebral body replacement with an anchored expandable titanium cage in the cervical spine after single-level and 2-level corpectomies.

METHODS

Between 2011 and 2017, 40 patients underwent a single-level (N = 32) or 2-level (N = 8) anterior corpectomy and fusion using an anchored expandable vertebral body replacement cage. Clinical and radiological data at admission, postoperatively, and at 3- and 12-mo follow-up were retrospectively analyzed. Clinical assessment was performed via standardized neurological evaluation, Odom score, and McCormick classification. Radiological assessment was performed via evaluation of sagittal profile, postoperative position, fusion, and subsidence rates.

RESULTS

Mean last follow-up was 14.8 ± 7 mo. Overall clinical and myelopathy-related improvements were shown directly after operation and at last follow-up. A stable centralized positioning of cages was achieved in 37 patients (93%). A mild ventral (>1.5 mm) malplacement was noted in 3 patients (7%) without clinical consequences. Sagittal alignment and preoperative cervical kyphosis improved significantly (7.8° gain of lordosis) and remained stable. Mean preoperative height of operated segments increased by 10 mm postoperatively and remained stable. Fusion rate in non-neoplastic patients and subsidence rate at last follow-up comprised 87.5% and 17.8%. With exception of 1 patient suffering from severe osteoporosis and cage subsidence, no patient needed additional secondary stabilization.

CONCLUSION

Anterior corpectomy and fusion by an expandable anchored titanium cage with anchor screws without additional instrumentation resulted in overall clinical improvement and radiological anterior column support, achieving significant and reliable restoration of the physiological sagittal cervical profile.

Outcome Evaluation of Zero-Profile Device Used for Single-Level Anterior Cervical Discectomy and Fusion with Osteoporosis Compared without Osteoporosis: A Minimum Three-Year Follow-Up Study

OBJECTIVE

We compared the mid-term efficacy and safety of anterior cervical discectomy and fusion (ACDF) using a Zero-Profile device for cervical degenerative disc disease (CDDD) with and without osteoporosis.

METHODS

We performed a retrospective study of elderly patients with CDDD treated by single-level ACDF with a Zero-Profile device. The patients were divided into group A (osteoporosis) and group B (no osteoporosis) according to the bone mineral density. The clinical outcomes (Japanese Orthopaedic Association, neck disability index, visual analog scale, and short-form 36 scores), radiological outcomes (cervical lordosis and fusion rate), and complications were reviewed at each follow-up examination.

RESULTS

All procedures were successfully performed in all patients. The Japanese Orthopaedic Association, neck disability index, visual analog scale, and short-form 36 scores and cervical lordosis were significantly improved postoperatively in both groups (P < 0.05). However, no significant difference was found between the 2 groups at each follow-up point (P > 0.05). No significant difference was found in the fusion rate at 3 months postoperatively (group A, 88.9%; group B, 90.0%), dysphagia rate at 1 month postoperatively (group A, 11.1%; group B, 15.0%), or cage subsidence rate at the final follow-up visit (group A, 11.1%; group B, 10.0%; P > 0.05). All patients achieved solid fusion, and no patient had dysphagia at the final follow-up examination.

CONCLUSIONS

ACDF with the Zero-Profile device can be used as an effective and reliable treatment for single-level CDDD with osteoporosis.

Corpectomy with adjacent-level kyphoplasty to treat metastatic lung cancer in three contiguous cervical vertebrae causing focal neurologic compromise

Study Design Case report. Objectives Decompression of metastatic spinal cord compression has been shown to improve quality of life and prolong ambulation in patients undergoing palliative treatment. We report a case of metastatic cervical myelopathy treated with a combined approach using corpectomy and stabilization together with balloon kyphoplasty to allow adequate decompression and immediate stability in a patient with significant destruction of adjacent vertebral bodies. Methods The cervical spine was approached anteriorly and decompressed with a C7 corpectomy. Subsequent stability was achieved with insertion of a trabecular metal cage. Balloon kyphoplasty was used to treat lytic lesions within the posterior body of the adjacent vertebrae for pain relief and increased stability. Additional stability was achieved through the application of an anterior plate. Results Full limited decompression and stabilization were successfully achieved. The patient had no further neurologic deterioration and made modest improvements that allowed a return to independent ambulation. Conclusion This limited approach may be an option for patients with metastatic spinal cord compression, lytic destruction of adjacent vertebral bodies, and limited life expectancy.