Utility of bioactive glasses as fusion substrates for cervical and lumbar fusion: a systematic review

Introduction

Spinal fusions are effective and established treatment options for various spine pathologies, and the number of patients undergoing these procedures has been steadily increasing over time (1-4). The historical gold standard fusion material has been autograft (AG) harvested from the iliac crest, although this process is associated with morbidity rates of 2.4–6.2% for complications like surgical site infection, hematoma formation, and residual pain (5). As such, costly cadaveric allografts, often in the form of demineralized bone matrix, are more frequently being utilized (6). In an effort to reduce the need for these materials, there has been an impetus to develop fully synthetic grafts that are efficient to produce and achieve comparable fusion rates.

Bioactive glasses (BGs) are a fully synthetic type of ceramic that have diverse applications as medical devices. Owing to their osteoconductive and osteoinductive properties, lack of donor site morbidity, and long-term cost-effectiveness, there is growing interest in exploring BGs as graft substitutes in spinal fusion (7-9). It is important to note that the term “bioactive glass” refers to a broad category of materials, each with unique chemical compositions. Although there are numerous clinical studies that have investigated the efficacy of BGs as fusion grafts, the current landscape of data is considerably disorganized due to variations in BG type, application of BGs, surgery type, and study design (10,11). Additionally, inconsistency in how adverse outcomes are reported between studies is also prevalent in the current literature. This heterogeneity in methodologies and results has made it difficult to extract meaningful conclusions applicable to surgical practice, as one study on BGs may report promising fusion rates as high as 100% (12), while another might show dismal rates as low as 0% (13).

In this study, we present an updated systematic review on the current landscape of clinical studies that investigate the use of BGs in cervical and lumbar spinal fusion, with a focus on fusion rates and adverse outcomes. Given the expected methodological heterogeneity between studies, we opt to conduct a systematic review without quantitative meta-analysis. The goal of this review is to provide context to the existing literature so future clinical research can focus on the most promising BG types and uses in spine surgery. We present this article in accordance with the PRISMA reporting checklist (available at https://jss.amegroups.com/article/view/10.21037/jss-25-110/rc).

Methods

Electronic database search and screening

Inclusion criteria were defined using the PICOS (patients, intervention, comparison, outcomes, and study design) principles, as shown in Table 1. Our literature search was conducted using keywords designed to find all available clinical studies involving BGs and spinal fusion. The databases queried were MEDLINE, Cochrane, Embase, and Web of Science. The literature search was conducted on March 26^th, 2024. Exclusion criteria included conference abstracts, comments, editorials, and preprints. For example, the query string used to search Cochrane was: (bioactiv* ADJ6 glass* OR CaO-SiO2-P2O5-B2O3 OR BGS-7 OR BGS7 OR bioglass* OR "45S5" OR "S53P4" OR BioSphere Putt* OR novomax) AND (spine OR spinal OR vertebrae OR vertebral OR intervertebral OR cervical OR lumbar OR lumbar interbody fusion OR lumbar inter-body fusion OR cervical decompress* OR cervical discectom* OR cervical diskectom* OR degenerative cervical disc OR cervical disc degeneration OR intervertebral disc degeneration OR degenerative intervertebral disc OR thoracic vertebrae). This query string was stylistically translated for proper use in each database.

The published, peer-reviewed studies found by our initial search included all those written in English on the use of any type of BG, including the most common ones of BGS-7 (CaO-SiO2-P2O5-B2O3) and Bioglass^® (45S5), in cervical, thoracic, or lumbar spinal fusion surgery. Duplicate studies were identified and removed using EndNote 20 (Clarivate, Philadelphia, PA, USA). The titles and abstracts of the remaining studies were then screened by two reviewers (K.G.L. and E.K.). Studies were excluded if they involved animal, cadaver, or in vitro experiments, had pediatric or dental populations, were retrospective in nature, or were review articles. A third reviewer (I.S.) provided arbitration in cases of disagreement. Studies that passed initial abstract screening were retrieved for full-text review, where they were further excluded if they did not report radiographic fusion rates or if they met the exclusion criteria from the first round of manual review. The studies that passed this full-text review were ultimately included in our systematic review.

Assessment of quality and data extraction

Risk of bias for included studies was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB 2), which takes into account randomization processes, deviations from intended interventions, missing outcome data, how outcomes are measured, and authors’ selection of reported results (14). In a similar manner to the literature screening process, each study and associated trial protocol (if available) was systematically evaluated for the above factors, with a final judgement being made of low, some concerns, or high risk of bias for each study.

For data collection, each included study was examined to extract descriptive characteristics as well as fusion rates and adverse events. The type of BG used, surgery type, inclusion criteria, study design, initial and follow-up sample size, and reasons for participant loss were recorded for each study. The percent of patients who achieved bony fusion and the percent of levels with successful fusion were recorded at the longest reported follow-up time. Adverse events to be collected included hardware migration, cage subsidence, hardware failure, pseudoarthrosis, osteolysis, postoperative dysphagia, reoperation, and any additional adverse outcome reported by the authors.

Results

Included studies after screening

From the initial database query, we identified 607 total studies, of which 209 were identified as duplicates and removed. Of the remaining 398 studies, 367 were excluded before full-text review. Among the 31 studies retrieved for full-text review, 19 were subsequently excluded, with 10 being retrospective in nature, five having dental or pediatric populations, two being cadaver studies, and another two being animal or in vitro studies. Ultimately, 12 studies were included in the final systematic review (Figure 1). Descriptive summaries of each of these studies along with their reported fusion rates are presented in Table 2. Rates of reported adverse outcomes are presented in Table 3. Of the 12 studies, none reported any subgroup analyses or results stratified by patient characteristics.

Figure 1 PRISMA flow diagram.

Effect of BGS-7 in posterior lumbar interbody fusion (PLIF)

Seven studies assessed the use of BGS-7 in spinal fusion, with three looking at PLIF (15-17) and four at anterior cervical discectomy and fusion (ACDF) (12,18-20). Of the three PLIF studies, Kwon et al. [2023] had patients receive either an AG-filled BGS-7 spacer or an AG-filled polyether ether ketone (PEEK) cage (15). This study’s 28% loss at follow-up raises some concern for bias, although there was a relatively equal number of patients lost from each group. The authors found that fusion rates were similar at 1 year postoperatively (77.8% BGS-7 vs. 81.0% PEEK, P=0.807), with two instances of hardware migration and one hardware failure in the BGS-7 group. However, average cage subsidence was significantly lower in the BGS-7 group (0.77 vs. 2.53 mm, P=0.001), and there was no difference in osteolysis by level between groups (25.0% BGS-7 vs. 21.4% PEEK, P=0.496).

The two other studies by Lee et al. are part of one longer trial comparing AG-filled BGS-7 spacers with AG-filled titanium spacers, with one reporting on 1-year follow-up data (17) and the other on 4-year follow-up results (16). These two studies’ patient blinding, randomization, complete follow-up, and multiple independent assessors of imaging lead to them having a low risk of bias. These studies found that fusion rates were similar both at 1 year (89.7% BGS-7 vs. 91.4% titanium, P>0.99) and at 4 years (90.6% BGS-7 vs. 93.3% titanium, P>0.99). In addition, the average cage subsidence (1.10 mm BGS-7 vs. 0.94 mm titanium, reported as non-significant by the authors) and osteolysis by level (7.7% BGS-7 vs. 5.9% titanium, reported as non-significant by the authors) were comparable at 1 year. Adverse event profiles at 4 years were not reported by the authors.

Use of BGS-7 in ACDF

For the four studies that assessed the use of BGS-7 in ACDF, two compared BGS-7 spacers with allograft cages (12,18), while two compared BGS-7 spacers with PEEK cages (19,20). One allograft-control study by Liu et al. that included comprehensive randomization and blinding strategies (low risk of bias) highlighted a non-significantly higher fusion rate in the allograft group (87.8% vs. 75.0%, reported as non-significant by the authors) compared to the BGS-7 group (18). Regarding adverse outcomes, there was one instance of pseudoarthrosis in the allograft group. The other allograft-control study by Ryu et al. was prospective in nature but examined a consecutive series of patients without randomization or blinding, which leads to a high risk of bias (12). This study reported a 100% fusion rate for the BGS-7 spacer group at an average of 7.5 years postoperatively compared to 88.5% for the allograft group (P=0.258). For adverse outcomes, in the allograft group, there were six hardware failures compared to none in the BGS-7 group, although the difference was not significant (P=0.708). However, allografts showed significantly higher subsidence compared to BGS-7 (2.27 vs. 1.33 mm, P=0.009) at 7.5 years postoperatively.

For the studies with PEEK cages as controls, the one by Park et al. was deemed to have low risk of bias due to its detailed blinding and randomization procedures and large sample size with complete patient follow-up (19), while the other by Kwon et al. [2024] was determined to have some concerns for bias due to a lack of true randomization (20). Park et al. (19) found a higher but non-significantly different fusion rate in the BGS-7 spacer group at 1 year postoperatively [81.8% vs. 74.4%, risk difference =7.4% (95% CI: −11.5% to 26.5%)] and reported no adverse outcomes. Kwon et al. (20) also found similar fusion rates (95.0% BGS-7 vs. 74.7% PEEK, P=0.970) and only reported one case of pseudoarthrosis in each group (P=0.970).

Use of S53P4 in posterolateral lumbar fusion (PLF)

Two studies investigated the use of S53P4 in PLF. Regarding bias, Frantzén et al.’s study has some concerns for bias as radiographic assessors were unblinded (21), while Rantakokko et al.’s study has a high risk of bias due to scant details about how fusion was determined radiographically (22). Additionally, both have small sample sizes of less than 20 with some patient dropout. Nevertheless, these studies are unique in that each patient received half S53P4 and half AG as standalone graft material, allowing patients to serve as their own controls. Frantzén et al. found that at 11 years postoperatively, only 80% of levels on the S53P4 side had achieved fusion compared to 100% of levels on the AG side (no P value reported) (21). For adverse events, the authors reported two instances of hardware migration, five hardware failures, and three instances of hardware loosening. The other study by Rantakokko et al. found a 71.4% fusion rate on the S53P4 side compared to 100% on the AG side at 10 years (no P value reported), and the authors did not report any adverse events (22). Due to the nature of having individuals serve as their own controls, comparing adverse events between groups is not possible in these studies.

Use of apatite- and wollastonite-containing glass-ceramic (AWGC) in PLF

One study by Kasai et al. investigated the use of AWGC in PLF (23). This study had no patient dropout when compared to the other PLF studies, but there are still some concerns for bias due to the lack of patient or investigator blinding. In this study, patients were divided into three groups and received either 1:2, 1:1, or 2:1 mixture ratio of AWGC to AG as standalone fusion grafts. At evaluation 2 years postoperatively, no group had achieved 100% fusion on X-ray, and according to the authors, each group had statistically similar fusion rates with no adverse events.

Use of Chitra-HABg in PLF

A single study by Acharya et al. looked at using Chitra-HABg as a standalone fusion graft in PLF. The risk of bias is of some concern in part due to the determination of fusion by a single, unblinded individual (13). This study also utilized each patient as their own control by placing either Chitra-HABg or AG on each side as a standalone graft. Notably, at 1-year follow-up, none of the patients had achieved solid bony fusion on the Chitra-HABg side, while 72.7% had fusion on the AG side (P<0.001). In fact, the authors reported that 77.3% of patients had experienced complete bone resorption on the Chitra-HABg side. The authors did not explicitly report any other adverse events, but again, the single-person control design would make it difficult to determine whether the BG alone contributed to any adverse outcomes.

Use of 45S5 in anterior lumbar interbody fusion (ALIF)

One study by Szadkowski et al. investigated the use of 45S5 (Glassbone^®) as graft material in ALIF (24). Its single-blinded design and use of a validated classification system for radiographic fusion result in this study having a low risk of bias. Notably, 60% of patients in this cohort received additional posterior instrumented fixation due to either having spondylolisthesis or requiring posterior decompression. As for the study design, the authors used a special cage that had two compartments separated by a midline beam, which allowed them to fill one side with 45S5 and the other with AG. At 1 year postoperatively, there was 52% fusion by total number of levels on the 45S5 side compared to 40% on the AG side (P=0.416). For adverse events, they reported one unspecified postoperative hematoma and one instance of new radiculopathy.

Discussion

Due to the known comorbidities associated with harvesting iliac crest bone graft (25-27) and the costs associated with producing cadaveric allograft (6,28), there has been a desire to find fully synthetic fusion graft materials that are easy to manufacture, cost-effective, and improve clinical outcomes. As BGs are both osteoconductive and osteoinductive, they have recently become a popular target in research on suitable graft replacements, although large design variations between studies have made it difficult to evaluate the utility of BG in spine surgery (10,11). Here, we presented an updated systematic review that included the most recent prospective clinical studies, looking at the impact of BG use on fusion rates and adverse outcomes.

We found that many of the available prospective studies on this topic have a high risk of bias due to methodological concerns, with only five out of 12 included studies being deemed to have low risk of bias. Common issues were a lack of stringent inclusion criteria, improper blinding or randomization, and small sample sizes that magnified the risk of results being biased by patient dropout. As a result, despite some studies having impressive follow-up times of 10 years or longer (21,22), their results must be interpreted with caution due to their less rigorous methodology. Additionally, due to the invasive nature of this type of research and the long follow-up times required to assess results, it is reasonable to expect a low volume of available studies with small individual sample sizes. However, given the large investment on both the part of the researcher and the patient in these studies, it is imperative that future studies are designed with rigorous methodologies that will allow us to confidently appreciate their results.

Notably, all included studies reported various patient-reported outcome (PRO) measures, although we decided not to focus on them in this review. This decision was based on the fact that a multitude of factors other than the degree of bony fusion contribute to PRO scores, such as severity of preoperative spine pathology, patient expectations (29), rates of follow-up (30), and patient satisfaction (31-33). As such, in the setting of finding a suitable fusion graft replacement, PROs seem to be less helpful in assessing graft efficacy. Additionally, we compiled the PRO data from the included studies and noted no significant differences in PROs between BG and control groups within studies (results not shown). Nonetheless, even if PROs in patients receiving BGs are noninferior to outcomes in those receiving standard grafts, switching to a material with inferior fusion capabilities would likely lead to an increased risk of long-term complications, such as hardware loosening and pseudoarthrosis.

The most recent systematic review by Cottrill et al. from 2020 included 12 clinical studies, with only five being prospective studies (10). In their meta-analysis, they found a mean fusion rate of 84% across all types of BGs. Although our updated systematic review contains more high-quality studies—with seven being from 2020 and later—we believed that a meta-analysis of fusion rates was unwarranted due to the large variation of BG types and methods of application (e.g., as a standalone fusion graft or as a cage material). As such, in this case, we deemed it best to present each study within its own context. Another recent systematic review on synthetic bone grafts by Salamanna et al. was only able to find a single prospective study on the use of BG in spinal fusion, which they believed was unsuitable for assessment due to its methodological limitations (11). Along these lines, although we were able to gather more prospective studies for our review, it does not change the fact that the limitations of individual studies should keep us cautious when trying to interpret grouped results.

It is crucial to note that within these studies, BG is used in two majorly different ways: as a bone graft substitute and as a cage material. Studies that compare BGs to AG show that using certain types of BG as standalone graft materials can vary from moderately to severely ineffective for fusion (13,21). However, one included study where AWGC was mixed with AG reported 2-year fusion rates between 81.8–83.3% (23). Comparatively, previously reported fusion rates for AG grafts in PLF at two years postoperatively range between 69% and 88% (34,35), and certain retrospective studies have reported 100% fusion at 2 years with AWGC-AG mixtures (36,37). The failure of some standalone BGs, including AWGC, may to some extent lie in their low mechanical strengths when used alone (38). Additionally, given that osteoconductivity partly requires new bone growth through the porous spaces between BG granules, supplying existing AG in those spaces may enhance a graft’s ability to solidify into a stable construct (39). Thus, more prospective studies on mixtures of BG and AG, especially AWGC-AG mixtures, as standalone fusion grafts are warranted.

In terms of comparing BGS-7 cages to PEEK, titanium, or allograft cages, all seven included studies showed similar performances between BGS-7 and other cage types in fusion rates. Notably, two studies reported significantly lower amounts of BGS-7 cage subsidence compared to PEEK and allograft cages (12,15). Given BGS-7’s high mechanical strength and high elastic modulus (40), these reportedly lower subsidence rates may indicate a role for its use in artificial disc design, especially in helping anchor discs to end plates in total disc arthroplasty without the use of stems or screws (41). Additional potential roles for BGs are in spinal column reconstruction after resection due to tumor, infection, or osteoporotic fractures, with some small case series demonstrating seemingly successful use in these areas (42-44). Nevertheless, only three of the BGS-7 studies included in our review were deemed as having low bias. As such, further high-quality investigations into the use of BGS-7 cages are needed to validate the noninferiority results from these studies.

Limitations

Despite our best efforts, this systematic review has several limitations. Requiring studies to be in English, possible reviewer bias, and incomplete searching within a limited number of databases may have caused potentially helpful studies to be missed. However, screening four separate large databases in a systematic method helped minimize the number of studies that could have been overlooked. Another limitation is that within each study, there was a lack of technical details surrounding how BG was used during surgery. How the BG was applied during PLF or how it was used to fill an ALIF cage could very well affect how effectively it promotes fusion, as increased BG contact with well-decorticated bone likely leads to improved bony fusion. Perhaps the major limitation in this study is the heterogeneity of the studies included in this review, which makes it difficult to compare specific BG types within a single surgical category. In addition to the methodological limitations within individual studies, some assessed fusion using computed tomography (CT) while others used X-ray, follow-up times varied between one and 11 years, some used mixtures of BGs with AG while others used pure BGs, and some used BG cages while others used standalone BG grafts, among other differences. Although practical hurdles, such as potentially still needing AG to mix with BGs, may exist, the largest barrier to real world implementation of BGs in spine surgery is undoubtedly the significant variation in the existing clinical literature, leading to difficulty applying their results to clinical practice. Nonetheless, this diversity should help us appreciate the utility of BGs in various contexts and keep us motivated in continuing focused research into their applications in spine surgery.

Conclusions

In this study, we conducted an updated systematic review looking at prospective clinical studies on the use of BGs in spinal fusion. We found that despite multiple new studies being published since the last systematic review on this topic, there is still severe methodological heterogeneity regarding BG type, method of BG use, surgery type, and study design. Studies using standalone Chitra-HABg and S53P4 grafts showed clear inferiority to AG, while mixtures of AWGC with AG could lead to promising fusion grafts. BGS-7 cages may allow for high rates of fusion; however, they must continue to be tested against allograft, PEEK, and titanium cages. The number of adverse events associated with BG products was not significant enough to warrant independent concern over its use in spine surgery, and BGS-7 cages may actually reduce long-term subsidence. As we continue to search for cost-effective, easy to produce, and clinically effective graft substitutes in spine fusion, BGs can provide a wide range of possibilities in their various types and applications.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the PRISMA reporting checklist. Available at https://jss.amegroups.com/article/view/10.21037/jss-25-110/rc

Peer Review File: Available at https://jss.amegroups.com/article/view/10.21037/jss-25-110/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-25-110/coif). M.A.A. has received other financial or non-financial support from ATEC. J.C.W. serves as an unpaid editorial board member of Journal of Spine Surgery from April 2024 to December 2026. He has received royalties from Biomet, Novapproach, Seaspine, Synthes, and GS Medical, consulting fees from DepuySynthes and Bioretec, and owns stock or stock options in Bone Biologics, Electrocore, PearlDiver, Surgitech, and Illuminant. R.J.H. has received funding grants from ATEC, NuVasive and has received consulting fees from Medtronic, Globus/NuVasive, Orthofix, SI-Bone, Cerapedics, and Evolution Spine. R.K.A. has received funding grants from NIH, Max BioPharma, and ATEC, has received consulting fees from Medtronic, Orthofix, Globus, and eCential Robotics, and owns stock or stock options in HIA Technologies, NeoOnc, and Globus. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Mobbs RJ, Phan K, Malham G, et al. Lumbar interbody fusion: techniques, indications and comparison of interbody fusion options including PLIF, TLIF, MI-TLIF, OLIF/ATP, LLIF and ALIF. J Spine Surg 2015;1:2-18. [Crossref] [PubMed]
2. Gould H, Sohail OA, Haines CM. Anterior cervical discectomy and fusion: Techniques, complications, and future directives. Semin Spine Surg 2020;32:100772.
3. Reisener MJ, Pumberger M, Shue J, et al. Trends in lumbar spinal fusion-a literature review. J Spine Surg 2020;6:752-61. [Crossref] [PubMed]
4. Mani K, Kleinbart E, Goldman SN, et al. Projections of Single-level and Multilevel Spinal Instrumentation Procedure Volume and Associated Costs for Medicare Patients to 2050. J Am Acad Orthop Surg Glob Res Rev 2024;8:e24.00053.
5. Uzodimma SC, Eyichukwu GO, Iyidobi EC, et al. Early bone graft donor site morbidities; anterior superior iliac crest versus proximal tibia. Musculoskelet Surg 2025;109:207-12. [Crossref] [PubMed]
6. Liao Z, Wang CH, Cui WL. Comparison of Allograft and Autograft in Lumbar Fusion for Lumbar Degenerative Diseases: A Systematic Review. J Invest Surg 2016;29:373-82. [Crossref] [PubMed]
7. Fiani B, Jarrah R, Shields J, et al. Enhanced biomaterials: systematic review of alternatives to supplement spine fusion including silicon nitride, bioactive glass, amino peptide bone graft, and tantalum. Neurosurg Focus 2021;50:E10. [Crossref] [PubMed]
8. Shearer A, Montazerian M, Sly JJ, et al. Trends and perspectives on the commercialization of bioactive glasses. Acta Biomater 2023;160:14-31. [Crossref] [PubMed]
9. Ortega B, Gardner C, Roberts S, et al. Ceramic Biologics for Bony Fusion-a Journey from First to Third Generations. Curr Rev Musculoskelet Med 2020;13:530-6. [Crossref] [PubMed]
10. Cottrill E, Pennington Z, Lankipalle N, et al. The effect of bioactive glasses on spinal fusion: A cross-disciplinary systematic review and meta-analysis of the preclinical and clinical data. J Clin Neurosci 2020;78:34-46. [Crossref] [PubMed]
11. Salamanna F, Tschon M, Borsari V, et al. Spinal fusion procedures in the adult and young population: a systematic review on allogenic bone and synthetic grafts when compared to autologous bone. J Mater Sci Mater Med 2020;31:51. [Crossref] [PubMed]
12. Ryu S, Ryu DS, Kim KS. Long-term results comparison after anterior cervical discectomy with BGS-7 spacer (NOVOMAX®-C) and allograft spacer: A prospective observational study. Front Bioeng Biotechnol 2023;11:1100462. [Crossref] [PubMed]
13. Acharya NK, Kumar RJ, Varma HK, et al. Hydroxyapatite-bioactive glass ceramic composite as stand-alone graft substitute for posterolateral fusion of lumbar spine: a prospective, matched, and controlled study. J Spinal Disord Tech 2008;21:106-11. [Crossref] [PubMed]
14. Higgins JPT, Savović J, Page MJ, et al. Chapter 8: Assessing risk of bias in a randomized trial. In: Higgins JPT, Thomas J, Chandler J, et al. editors. Cochrane Handbook for Systematic Reviews of Interventions. 2nd ed. Chichester: Wiley-Blackwell Cochrane; 2019:205-28.
15. Kwon BT, Kim HJ, Lee S, et al. Feasibility and safety of a CaO-SiO2-P2O5-B2O3 bioactive glass ceramic spacer in posterior lumbar interbody fusion compared with polyetheretherketone cage: a prospective randomized controlled trial. Acta Neurochir (Wien) 2023;165:135-44. [Crossref] [PubMed]
16. Lee JH, Kim SK, Kang SS, et al. A Long-Term Follow-up, Multicenter, Comparative Study of the Radiologic, and Clinical Results Between a CaO-SiO2-P2O5-B2O3 Bioactive Glass Ceramics (BGS-7) Intervertebral Spacer and Titanium Cage in 1-Level Posterior Lumbar Interbody Fusion. Clin Spine Surg 2020;33:E322-9. [Crossref] [PubMed]
17. Lee JH, Kong CB, Yang JJ, et al. Comparison of fusion rate and clinical results between CaO-SiO(2)-P(2)O(5)-B(2)O(3) bioactive glass ceramics spacer with titanium cages in posterior lumbar interbody fusion. Spine J 2016;16:1367-76. [Crossref] [PubMed]
18. Liu Y, Park CW, Pholprajug P, et al. Efficacy of Allograft Versus Bioactive Glass-Ceramic Cage in Anterior Cervical Discectomy and Fusion: A Randomized Controlled Study. Global Spine J 2025;15:981-92. [Crossref] [PubMed]
19. Park J, Park SM, Ham DW, et al. Anterior Cervical Discectomy and Fusion Performed Using a CaO-SiO(2)-P(2)O(5)-B(2)O(3) Bioactive Glass Ceramic or Polyetheretherketone Cage Filled with Hydroxyapatite/β-Tricalcium Phosphate: A Prospective Randomized Controlled Trial. J Clin Med 2023;12:4069. [Crossref] [PubMed]
20. Kwon JW, Lee YH, Lee BH, et al. Clinical and radiological outcomes of non-window-type bioactive glass-ceramic cage in single-level ACDF versus PEEK cage filled with autologous bone. Sci Rep 2024;14:4035. [Crossref] [PubMed]
21. Frantzén J, Rantakokko J, Aro HT, et al. Instrumented spondylodesis in degenerative spondylolisthesis with bioactive glass and autologous bone: a prospective 11-year follow-up. J Spinal Disord Tech 2011;24:455-61. [Crossref] [PubMed]
22. Rantakokko J, Frantzén JP, Heinänen J, et al. Posterolateral spondylodesis using bioactive glass S53P4 and autogenous bone in instrumented unstable lumbar spine burst fractures. A prospective 10-year follow-up study. Scand J Surg 2012;101:66-71. [Crossref] [PubMed]
23. Kasai Y, Takegami K, Uchida A. Mixture ratios of local bone to artificial bone in lumbar posterolateral fusion. J Spinal Disord Tech 2003;16:31-7. [Crossref] [PubMed]
24. Szadkowski M, Bahroun S, Aleksic I, et al. Bioactive glass grants equivalent fusion compared to autologous iliac crest bone for ALIF: a within-patient comparative study. J Exp Orthop 2022;9:56. [Crossref] [PubMed]
25. Tonk G, Yadav PKR, Agarwal S, et al. Donor site morbidity in autologous bone grafting – A comparison between different techniques of anterior iliac crest bone harvesting: A prospective study. J Orthop Trauma Rehabil 2022;29: [Crossref]
26. Silber JS, Anderson DG, Daffner SD, et al. Donor site morbidity after anterior iliac crest bone harvest for single-level anterior cervical discectomy and fusion. Spine (Phila Pa 1976) 2003;28:134-9. [Crossref] [PubMed]
27. Boehm KS, Al-Taha M, Morzycki A, et al. Donor Site Morbidities of Iliac Crest Bone Graft in Craniofacial Surgery: A Systematic Review. Ann Plast Surg 2019;83:352-8. [Crossref] [PubMed]
28. Ehrler DM, Vaccaro AR. The use of allograft bone in lumbar spine surgery. Clin Orthop Relat Res 2000;38-45. [Crossref] [PubMed]
29. Zhang H, Glassman SD, Bisson EF, et al. Patient expectations impact patient-reported outcomes and satisfaction after lumbar fusion. Spine J 2024;24:273-7. [Crossref] [PubMed]
30. Patel MR, Jacob KC, Parsons AW, et al. How Do Patient-Reported Outcomes Vary Between Lumbar Fusion Patients with Complete Versus Incomplete Follow-Up? World Neurosurg 2022;158:e717-25. [Crossref] [PubMed]
31. Crawford CH 3rd, Carreon LY, Bydon M, et al. Impact of preoperative diagnosis on patient satisfaction following lumbar spine surgery. J Neurosurg Spine 2017;26:709-15. [Crossref] [PubMed]
32. Levin JM, Winkelman RD, Tanenbaum JE, et al. Key drivers of patient satisfaction in lumbar spine surgery. J Neurosurg Spine 2018;28:586-92. [Crossref] [PubMed]
33. Krauss P, Reinartz F, Sonnleitner C, et al. The Relation of Patient Expectations, Satisfaction, and Outcome in Surgery of the Cervical Spine: A Prospective Study. Spine (Phila Pa 1976) 2022;47:849-58. [Crossref] [PubMed]
34. Lehr AM, Oner FC, Delawi D, et al. Increasing Fusion Rate Between 1 and 2 Years After Instrumented Posterolateral Spinal Fusion and the Role of Bone Grafting. Spine (Phila Pa 1976) 2020;45:1403-10. [Crossref] [PubMed]
35. Høy K, Bünger C, Niederman B, et al. Transforaminal lumbar interbody fusion (TLIF) versus posterolateral instrumented fusion (PLF) in degenerative lumbar disorders: a randomized clinical trial with 2-year follow-up. Eur Spine J 2013;22:2022-9. [Crossref] [PubMed]
36. Ido K, Asada Y, Sakamoto T, et al. Radiographic evaluation of bioactive glass-ceramic grafts in postero-lateral lumbar fusion. Spinal Cord 2000;38:315-8. [Crossref] [PubMed]
37. Hashimoto T, Shigenobu K, Kanayama M, et al. Clinical results of single-level posterior lumbar interbody fusion using the Brantigan I/F carbon cage filled with a mixture of local morselized bone and bioactive ceramic granules. Spine (Phila Pa 1976) 2002;27:258-62. [Crossref] [PubMed]
38. Shinzato S, Nakamura T, Ando K, et al. Mechanical properties and osteoconductivity of new bioactive composites consisting of partially crystallized glass beads and poly(methyl methacrylate). J Biomed Mater Res 2002;60:556-63. [Crossref] [PubMed]
39. Lindfors NC, Aho AJ. Tissue response to bioactive glass and autogenous bone in the rabbit spine. Eur Spine J 2000;9:30-5. [Crossref] [PubMed]
40. Jo ML, Son DM, Shin DA, et al. Subsidence Performance of the Bioactive Glass-Ceramic (CaO-SiO(2)-P(2)O(5)-B(2)O(3)) Spacer in Terms of Modulus of Elasticity and Contact Area: Mechanical Test and Finite Element Analysis. World Neurosurg 2023;180:e1-e10. [Crossref] [PubMed]
41. Foreman M, Patel A, Nguyen A, et al. Management Considerations for Total Intervertebral Disc Replacement. World Neurosurg 2024;181:125-36. [Crossref] [PubMed]
42. Chalamgari A, Valle D, Palau Villarreal X, et al. Vertebral Primary Bone Lesions: Review of Management Options. Curr Oncol 2023;30:3064-78. [Crossref] [PubMed]
43. Kankare J, Lindfors NC. Reconstruction of Vertebral Bone Defects using an Expandable Replacement Device and Bioactive Glass S53P4 in the Treatment of Vertebral Osteomyelitis: Three Patients and Three Pathogens. Scand J Surg 2016;105:248-53. [Crossref] [PubMed]
44. Kaneda K, Asano S, Hashimoto T, et al. The treatment of osteoporotic-posttraumatic vertebral collapse using the Kaneda device and a bioactive ceramic vertebral prosthesis. Spine (Phila Pa 1976) 1992;17:S295-303. [Crossref] [PubMed]