Teriparatide and bisphosphonate use in osteoporotic spinal fusion patients: a systematic review and meta-analysis

Assessment of evidence for the off-label application of osteoanabolic drugs in fracture healing and spinal fusion

Osteoanabolic drugs are sometimes prescribed off-label for "fracture healing and spinal fusion." This study examines the scientific validity of such practices by analyzing existing clinical reports. The purported bone union-promoting effect of teriparatide in fracture cases has been refuted in clinical trials. While teriparatide shows efficacy in accelerating spinal fusion after surgery for patients with osteoporosis, there is no scientific justification for its off-label use in patients without osteoporosis. For osteoporosis patients, no clear evidence suggests that teriparatide is superior to antiresorptive drugs, making the rationale for switching from antiresorptive drugs to teriparatide weak. The efficacy in postoperative spinal fusion may primarily be attributed to systemic improvements in bone quality and quantity, enhancing the mechanical engagement of implants. The clinical evidence for the off-label use of romosozumab, another osteoanabolic drug, in fracture healing and spinal fusion is insufficient to support its efficacy. In conclusion, osteoanabolic drugs, like antiresorptive drugs, primarily have systemic functions in osteoporosis patients, with limited evidence supporting their role in promoting localized bone formation in fractures or spinal fusions.

In Vivo Performance of a Novel Hyper-Crosslinked Carbohydrate Polymer Bone Graft Substitute for Spinal Fusion

Bone graft materials are essential for achieving arthrodesis after spine surgery. Safe bone graft products, with osteoinductive, osteoconductive properties and the ability to monitor fusion in real-time, are highly desirable. A novel hyper-crosslinked carbohydrate polymer (HCCP) bone graft substitute was shown to aid in bone regeneration in critical-size defect studies in a rabbit model. These studies further evaluated the in vivo application of HCCP as a bone graft substitute in an ovine model of spinal fusion and a retrospective study in adult human spine surgery patients. Sheep studies demonstrated the safety and efficacy of HCCP with no evidence of adverse histopathology over 6 months of follow-up. In human studies, patients (N = 63) underwent posterolateral fusion with HCCP, with follow-up to assess fusion success. No adverse reaction related to the HCCP bone graft substitute was identified. Fusion success was noted to be non-inferior to other bone graft substitutes. HCCP appears to be a safe bone void filler adjunct for use in spinal fusion surgery for both trauma and degenerative disease. It has a good degradation profile for forming bone with the ability to provide new vasculature and may also function as a scaffold to carry cells, medications, and growth factors. Given the safety profile experienced in our preclinical and clinical studies, future investigation into its efficacy to achieve solid fusion is currently ongoing.

A Bone Health Optimization Framework for Malaysia: a position paper by the Malaysian Bone Health Optimization Network (MyBONe)

This position paper aims to establish and standardise Bone Health Optimization (BHO) strategies for older patients undergoing elective orthopaedic surgeries in Malaysia. It emphasises pre-, intra-, and post-operative assessments and tailored management. Adopting the "5IQ" approach, it proposes clinical standards and a registry to improve surgical outcomes and patient care.

PURPOSE

Osteoporosis and osteopenia are highly prevalent among older patients scheduled for elective arthroplasties and spinal surgeries. This position paper aims to establish, promote, and standardise effective Bone Health Optimization (BHO) strategies for such patients within orthopaedic practices in Malaysia. It emphasises the need for bone health assessments to be undertaken at the pre-operative, intra-operative, and post-operative stages, with tailored management strategies to meet individual patient needs.

METHODOLOGY

A comprehensive literature review was conducted, focusing on articles published from 2019 to 2024. Twelve broad themes were defined including definitions and importance of BHO, epidemiological data, assessment techniques, risk stratification, management strategies, and outcome metrics.

RESULTS

Elective surgeries on patients with poor bone health are associated with adverse outcomes, such as periprosthetic fractures, aseptic loosening of implants, and complications after spinal surgeries. This position paper advocates for routine bone health assessments and monitoring during the pre-operative, intra-operative, and post-operative phases. It provides summaries of imaging modalities, risk assessment tools, and techniques for each phase. By adapting the successful "5IQ" approach from secondary fracture prevention, we propose 5IQ-based Clinical Standards for BHO, including 18 Key Performance Indicators. A Malaysian BHO Registry is proposed to benchmark care in real-time and support a national quality improvement programme. Practical resources, such as a BHO algorithm and key practice points, are included.

CONCLUSION

This position paper proposes a paradigm shift in the management of bone health for patients undergoing elective orthopaedic surgery in Malaysia, aiming to improve surgical outcomes and patient care through standardised BHO strategies.

Treatment Strategies in the Osteoporotic Spine

This article reviews the appropriate assessment and management of osteoporotic compression fractures and discusses the implications of osteoporosis on initial patient evaluation, medical optimization for surgery, selection of instrumentation, and surgical technique. Adverse outcomes associated with osteoporosis are discussed. Failure to appropriately evaluate, optimize, and treat spine patients with osteoporotic bone can lead to disastrous complications. Weakened bone can lead to implant failure through cage subsidence and screw pullout, as well as, peri-implant fractures, failure of deformity correction, and proximal kyphosis. These risks must be taken into account when considering operative interventions in these patients.

The Effects of Longer Use of Teriparatide on Clinical and Radiographic Outcomes after Spinal Fusion in Geriatric Patients

Background: Teriparatide is an anabolic agent for osteoporosis and is believed to improve the bone healing process. Previous studies showed that teriparatide could enhance not only fracture healing but also spine fusion. It has been reported that use of teriparatide could promote the spine fusion process and decrease mechanical complications. However, there was no consensus regarding optimal treatment duration. The purpose of this study was to compare surgical outcomes between short-duration and long-duration teriparatide treatment after lumbar fusion surgery in elderly patients. Materials and Methods: All consecutive patients older than 60 years who underwent 1-level lumbar fusion surgery for degenerative diseases between January 2015 and December 2019 were retrospectively reviewed. Based on the duration of teriparatide treatment (daily subcutaneous injection of 20 µg teriparatide), patients were subdivided into two groups: a short-duration (SD) group (<6 months) and a long-duration (LD) group (≥6 months). Mechanical complications, such as screw loosening, cage subsidence, and adjacent vertebral fractures, were investigated. Postoperative 1-year union rate was also evaluated on computed tomography. Clinical outcomes were recorded using visual analog scale (VAS) and Oswestry Disability Index (ODI). Between-group differences for these radiographic and clinical outcomes were analyzed. Results: Ninety-one patients were reviewed in this study, including sixty patients in the SD group and thirty-one patients in the LD group. Their mean age was 72.3 ± 6.2 years, and 79 patients were female. Mean T-score was -3.3 ± 0.8. Cage subsidence (6.7% vs. 3.2%), screw loosening (28.3% vs. 35.5%), and adjacent vertebral fracture (6.7% vs. 9.7%) were not significantly different between the SD and LD groups. Union rate at 1-year postoperative was 65.0% in the SD group and 87.1% in the LD group (p = 0.028). Both groups showed improvement in VAS and ODI after surgery. However, the differences of VAS from preoperative to 6 months and 1 year postoperative were significantly higher in the LD group. Conclusions: Longer teriparatide treatment after lumbar fusion surgery resulted in a higher union rate at 1-year postoperative than the shorter treatment. Also, it could be more beneficial for clinical outcomes.

Effectiveness of Teriparatide for Spine Fusion in Osteoporotic Patient: A Systematic Review and Meta-Analysis of Comparative Studies

OBJECTIVE

Our goal was to assess teriparatide's (TP) effectiveness in improving radiographic and functional outcomes after spinal fusion surgery. This meta-analysis included randomized controlled trials (RCTs) and comparative cohort studies. The findings provide valuable insights and guidance for surgeons treating osteoporotic patients undergoing spinal fusion surgery.

METHODS

We conducted a systematic review to assess TP's efficacy in spinal fusion surgery for osteoporosis. Through thorough selection, data extraction, and quality assessment, we employed network meta-analysis to evaluate radiographic outcomes (fusion rate, screw loosening, vertebral fracture) and changes in bone mineral density measured by Hounsfield units. Functional outcomes were assessed using the Oswestry Disability Index scales. Our study aims to comprehensively understand TP's impact and effectiveness in spinal fusion surgery.

RESULTS

A total of 868 patients were included in the analysis. All patients underwent thoracolumbar internal fixation fusion surgery and were divided into following 2 groups: the TP treatment group and the control group. The results revealed significant differences in radiological outcomes. The fusion rate showed a significant difference, as well as screw loosening, and bone mineral density measured in Hounsfield units. However, there was no significant difference in vertebral fracture. The TP group demonstrated favorable effects with statistical significance. In terms of functional outcomes, there was no significant difference in the assessment of Oswestry Disability Index scores between the 2 treatment groups.

CONCLUSIONS

The meta-analysis demonstrated that the TP group exhibited significantly better outcomes, particularly in radiological measures, when compared to the control group. The use of TP in spinal fusion surgery shows promise in reducing postoperative complications and providing overall benefits.

Meta-analysis of clinical fracture risk reduction of anti-osteoporosis drugs: direct and indirect comparisons and meta-regressions

OBJECTIVE

Anti-osteoporotic drug (AOD) trials have variabilities in duration and fracture risks. This study evaluated AOD's versus controls regarding reduction in relative rates (rr) and rate differences (rd) of vertebral and hip fractures and comparative costs.

METHODS

Primary randomized-controlled trials (RCT's) of AOD's in post-menopausal women with documentation of vertebral fracture rates (VFR) or hip fracture rates (HFR) were extracted from meta-analyses and PubMed through February 2021. Direct and indirect meta-analysis and meta-regression analyzed fracture reductions.

RESULTS

There were 24 RCT's of drug-versus-placebo (73,862 women) and 10 drug-versus-drug trials. Reduction in rr of VFR were significant for anti-resorptive (alendronate, risedronate, zoledronate, denosumab, raloxifene) and anabolic (teriparatide, abaloparatide, romosozumab) drugs. Denosumab, teriparatide and abaloparatide were more effective in reducing VFR compared to oral bisphosphates (all p <0.05) but not to zoledronate. Reduction in HFR were significant for alendronate, denosumab and zoledronate (all p <0.05), without significant differences among drugs. Anabolic drugs did not show significant HFR reduction. Meta-regression of rd's allowed for calculation of costs per vertebral fracture prevented, which were estimated at >$100,000 for anabolic drugs and between $2,289-$28,947 for anti-resorptive drugs. Drug-versus-drug trials were underpowered to demonstrate changes.

CONCLUSIONS

This study suggests goal-directed, cost-effective therapy relative to a patient's risk for vertebral and hip fractures. Anabolic drugs are better at preventing vertebral fractures compared to oral bisphosphonates. Anabolic drugs are not superior to zoledronate or denosumab, and at substantially higher cost. In comparing drugs which prevented hip fractures, there was no statistical benefit of any drug.