What are the implications of Prolia (denosumab) on osteopenia in a patient undergoing spinal fusion surgery?

From the Guidelines

For a patient with osteopenia who is on Prolia (denosumab) and facing spinal fusion surgery, I strongly recommend continuing Prolia therapy without interruption before surgery, as it has been shown to reduce the risk of fracture and improve bone density 1. The standard Prolia regimen of 60 mg subcutaneously every 6 months should be maintained according to the patient's established schedule. If the next Prolia dose is due within 1-2 months after surgery, consider administering it 7-10 days before the procedure to avoid the immediate post-operative period. Adequate calcium (1000-1200 mg daily) and vitamin D (800-1000 IU daily) supplementation should be continued throughout the perioperative period. Prolia actually offers benefits for spinal fusion as it inhibits bone resorption while allowing continued bone formation, potentially improving fusion rates and hardware stability, as supported by the findings that denosumab reduces the risk of vertebral fractures 1. Importantly, unlike bisphosphonates, Prolia has not been associated with impaired bone healing or increased risk of atypical fractures in the short term. Discontinuing Prolia before surgery could trigger a rebound effect with accelerated bone loss and increased fracture risk, which would be particularly problematic during the recovery period when mobility may be limited. The surgeon should be informed about the patient's Prolia treatment to ensure appropriate perioperative management. Some key points to consider include:

• The benefits of continuing Prolia therapy, including reduced fracture risk and improved bone density
• The importance of maintaining adequate calcium and vitamin D supplementation
• The potential risks of discontinuing Prolia therapy, including rebound effect and increased fracture risk
• The need for close communication with the surgeon to ensure appropriate perioperative management. It is also worth noting that the European Calcified Tissue Society suggests the use of a bisphosphonate to reduce the risk of vertebral fractures upon stopping denosumab 1, but this is not relevant in this case as we are recommending continuation of Prolia therapy.

From the Research

Implications of Prolia (Denosumab) on Osteopenia in Spinal Fusion Surgery

• The use of denosumab, a medication used to treat osteoporosis, has been studied in the context of spinal fusion surgery, particularly in patients with osteopenia or osteoporosis 2, 3.
• A network meta-analysis found that teriparatide combined with denosumab was the most effective treatment in increasing the fusion rate and decreasing the Oswestry Disability Index (ODI) in patients undergoing spinal fusion surgery 3.
• Another study found that pretreatment with medications to prevent bone loss, including denosumab, prior to surgery was associated with lower pseudarthrosis and revision surgery rates, although the differences did not reach statistical significance 2.
• The effectiveness of denosumab in improving radiographic and functional outcomes after spinal fusion surgery in osteoporotic patients has not been directly studied, but its use in combination with teriparatide has shown promise 4, 3.

Comparison with Other Treatments

• Teriparatide has been shown to be effective in improving radiographic and functional outcomes after spinal fusion surgery in osteoporotic patients, and its use has been associated with lower odds of related complications 5, 4.
• Bisphosphonates, another type of medication used to treat osteoporosis, have been found to have no effect on operative nonunion rates in patients with osteoporosis, but may have a beneficial effect in patients with osteopenia 6.
• The use of denosumab in combination with teriparatide has been found to be more effective than teriparatide alone in increasing the fusion rate and decreasing the ODI in patients undergoing spinal fusion surgery 3.

Limitations and Future Directions

• Further studies are needed to determine the effectiveness of denosumab in improving outcomes after spinal fusion surgery in patients with osteopenia, and to compare its effects with those of other treatments 2, 6.
• The optimal timing and duration of denosumab treatment in the context of spinal fusion surgery are not well established, and further research is needed to determine the best treatment strategies 6.