Anti-osteoporosis medication in patients with posterior spine fusion: a systematic review and meta-analysis.

Background context: Osteoporosis and osteopenia are common among patients undergoing posterior spine fusion surgery, presenting challenges such as pseudarthrosis, screw loosening, and poor patient outcomes. While pharmacological interventions are available, no consensus exists regarding the optimal perioperative treatment for these patients. Furthermore, the effectiveness of various treatment options in improving fusion rates and minimizing complications remains uncertain.

Purpose: To compare the effects of teriparatide, bisphosphonates, denosumab, and romosozumab in patients with posterior spine fusion with low bone mineral density (BMD).

Study design: Systematic review and meta-analysis PATIENT SAMPLE: Adult patients with low BMD receiving osteoporosis medications and undergoing posterior spine fusion surgery OUTCOME MEASURES: Fusion rate, subsequent vertebral fracture (VF), screw loosening, cage subsidence, proximal junctional kyphosis(PJK), and patient-reported outcomes (PROs), particularly the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI).

Methods: A systematic search was conducted using PubMed, EMBASE, and Cochrane Library. Two reviewers independently selected and assessed relevant studies. Four groups were analyzed to evaluate the comparative effectiveness of antiosteoporosis medication on the outcome measures: Bisphosphonate versus Control; Teriparatide versus Control; Teriparatide versus Bisphosphonate; and Denosumab versus Control.

Results: Bisphosphonate showed reduced subsequent VFs (odds ratio [OR]=0.27, 95% confidence interval [CI]=0.09-0.81) and cage subsidence (OR=0.29, 95% CI=0.11-0.75) and improved ODI scores at 12 months (standardized mean difference [SMD] [95% CI]=-0.75 [-1.42, -0.08]) compared to the control. Teriparatide showed a higher fusion rate (OR=3.52, 95% CI=1.84-6.75), lower screw loosening (OR=0.23, 95% CI=0.09-0.60), and improved ODI scores at 24 months (SMD [95% CI]=-0.57 [-0.99, -0.15]) compared to the control. Moreover, teriparatide showed a higher fusion rate (OR=2.28, 95% CI=1.67-3.11), lower subsequent VF (OR=0.22, 95% CI=0.09-0.51), and improved VAS score for back pain (VASB) (mean difference [MD] [95% CI]=-0.30 [-0.54, -0.07]) and ODI (SMD [95% CI]=-0.38[-0.64, -0.12]) scores at 12 months compared to bisphosphonate. Denosumab showed no significant difference in fusion rate or other complications compared to control.

Conclusion: Our results indicated that teriparatide should be used as the first-line perioperative treatment for patients with poor bone quality scheduled for posterior spine fusion. Teriparatide exhibited better fusion rates and reduced complications than controls and bisphosphonates, resulting in improved PROs. Moreover, bisphosphonates can be utilized in patients with contraindications to teriparatide since the former prevents osteoporosis-related complications compared to controls, resulting in improved PROs. Further studies are warranted to evaluate the potential effects of denosumab and romosozumab.