Researchers studied 54 patients with weak bones who had spine surgery to fuse vertebrae together. They compared three groups: one taking denosumab (a bone-strengthening injection), one taking bisphosphonates (another bone-strengthening medication), and one taking only calcium and vitamin D. After six months, patients taking either denosumab or bisphosphonates showed better bone fusion compared to the control group. Denosumab also caused fewer fevers after surgery. Both medications appear to help bones heal faster after this type of spine surgery, though more research is needed to confirm long-term benefits.

The Quick Take

  • What they studied: Whether two bone-strengthening medications (denosumab and bisphosphonates) help bones fuse better after spine surgery in people with weak bones.
  • Who participated: 54 patients with osteopenia or osteoporosis (weak bones) who needed midline lumbar fusion surgery. The group was divided into three equal treatment groups.
  • Key finding: After 6 months, patients taking denosumab or bisphosphonates had significantly better bone fusion rates (about 94% partial or complete fusion) compared to those taking only calcium and vitamin D (about 68% fusion). Denosumab also resulted in fewer post-surgery fevers.
  • What it means for you: If you have weak bones and need spine fusion surgery, your doctor may recommend bone-strengthening medication to help your bones heal better. However, this is a short-term study, so talk with your doctor about whether these medications are right for your situation.

The Research Details

This was a prospective cohort study, which means researchers followed patients forward in time after they received treatment. Researchers enrolled 54 patients with weak bones (osteopenia or osteoporosis) who were having midline lumbar fusion surgery—a procedure where doctors fuse vertebrae in the lower spine together. Patients were divided into three groups: one receiving denosumab (a bone-strengthening injection given under the skin), one receiving bisphosphonates (a bone-strengthening medication given through an IV), and one receiving only calcium and vitamin D supplements as a control group. Researchers tracked how well the bones fused together, measured pain and function using standard scoring systems, tested blood markers related to bone health, and monitored for any side effects over six months.

This research approach is important because it allows doctors to see how treatments work in real patients undergoing actual surgery, rather than just in laboratory settings. By comparing three groups side-by-side, researchers could determine whether the bone-strengthening medications truly made a difference beyond just giving calcium and vitamin D. The prospective design (following patients forward in time) provides stronger evidence than simply looking back at past medical records.

This study has some strengths: it compared three groups directly, measured multiple outcomes (fusion rates, pain scores, and blood markers), and tracked patients for six months. However, readers should know that the study was relatively small (54 patients), and the COVID-19 pandemic affected follow-up, with only 29 patients completing the final assessment. This is a short-term study, so we don’t know if benefits continue beyond six months. The study was published in a peer-reviewed journal, which means other experts reviewed it before publication.

What the Results Show

At the six-month follow-up, bone fusion rates were significantly better in both treatment groups compared to the control group. In the denosumab group, 25% of patients achieved complete bone fusion and 68.6% achieved partial fusion (total 93.6%). In the bisphosphonate group, 25% achieved complete fusion and 75% achieved partial fusion (total 100%). In the control group (calcium and vitamin D only), only 10.5% achieved complete fusion and 57.9% achieved partial fusion (total 68.4%). These differences were statistically significant, meaning they were unlikely to occur by chance. Additionally, bone metabolism markers (blood tests measuring bone health) showed better improvement in the denosumab and bisphosphonate groups compared to control. Denosumab was associated with a lower rate of post-operative fever (23.5%) compared to bisphosphonates (35.3%), which was also statistically significant.

Clinical scores measuring pain and function improved in all groups over six months, but the improvement was greater in the denosumab and bisphosphonate groups. No serious adverse events were reported in any group. The denosumab group had fewer post-operative fevers, which is an important practical benefit since fever can complicate recovery. Both medications appeared to be well-tolerated overall.

This study builds on existing research showing that bone-strengthening medications can help with bone healing. Previous studies have suggested that bisphosphonates may improve fusion rates, but there has been less research on denosumab for this specific surgery. This study is one of the first to directly compare denosumab and bisphosphonates for spine fusion in patients with weak bones, suggesting that denosumab may be equally effective with fewer side effects like fever.

Several limitations should be considered: the study was relatively small with only 54 patients, which limits how much we can generalize the findings. The COVID-19 pandemic disrupted follow-up, with only 29 patients completing the final assessment, which weakens the conclusions. The study only followed patients for six months, so we don’t know if the benefits continue longer or if any delayed side effects occur. The study didn’t include information about patient age, sex, or severity of bone weakness, which could affect results. Finally, this was a single-center study, so results may not apply to all hospitals or patient populations.

The Bottom Line

Based on this short-term study, both denosumab and bisphosphonates appear to improve bone fusion after spine surgery in patients with weak bones. Denosumab may be slightly preferred due to fewer post-operative fevers. However, these are preliminary findings, and patients should discuss with their spine surgeon which medication is best for their individual situation. This recommendation has moderate confidence due to the small sample size and short follow-up period.

This research is most relevant for people with osteopenia or osteoporosis who are considering or scheduled for midline lumbar fusion spine surgery. Spine surgeons and orthopedic specialists should be aware of these findings when planning perioperative care. People without weak bones undergoing spine surgery may not benefit from these medications. Patients with kidney disease or other medical conditions should discuss safety with their doctor before starting these medications.

Based on this study, improvements in bone fusion appear within the first six months after surgery. However, complete bone fusion typically takes longer (often 12-24 months), so patients should expect gradual improvement over time. The benefits of these medications during the critical early healing phase (first six months) appear to set the stage for better long-term outcomes, but longer studies are needed to confirm this.

Want to Apply This Research?

  • Track post-operative symptoms weekly: record any fever, pain levels (0-10 scale), and mobility improvements. Note medication doses and dates taken. This helps you and your doctor monitor how well the treatment is working.
  • If prescribed denosumab or bisphosphonates, set reminders for medication administration and follow-up appointments. Log any side effects or concerns immediately. Maintain calcium and vitamin D intake as recommended, and follow physical therapy guidelines for post-operative recovery.
  • Create a six-month tracking dashboard showing: weekly pain and fever logs, monthly mobility assessments, medication adherence, and appointment completion. Share this data with your surgical team at follow-up visits to monitor fusion progress and adjust treatment if needed.

This research summary is for educational purposes only and should not replace professional medical advice. The findings are based on a small, short-term study and may not apply to all patients. If you have weak bones and are considering spine surgery, discuss these medications with your spine surgeon or orthopedic specialist to determine if they are appropriate for your specific situation. Do not start, stop, or change any medications without consulting your healthcare provider. Patients with kidney disease, certain cancers, or other medical conditions may not be candidates for these medications. Always inform your doctor about all medications and supplements you are taking.