184. Denosumab protects against bone loss and maintains function in osteopenic patients with lumbar degenerative diseases after lumbar fusion surgery: a randomized controlled trial

BACKGROUND CONTEXT Denosumab has been shown to be effective in increasing bone mineral density (BMD) in postmenopausal women with osteoporosis. However, the effect of denosumab on BMD, bone turnover markers (BTMs), and functional status in osteopenic patients after spinal fusion remains unknown. PURPOSE We aimed to investigate the effect of denosumab on BMD of the lumbar, total hip, femoral neck, and BTMs of P1NP1 and CTX. We also aimed to investigate secondary measures post denosumab treatment including Visual Analogue Scale (VAS) and health questionnaire scores, associated complications, and adverse events after lumbar fusion surgery during a 12-month follow-up period. STUDY DESIGN/SETTING We performed a randomized, double blinded, placebo-controlled clinical trial in osteopenic patients with lumbar degenerative diseases. PATIENT SAMPLE A total of 76 osteopenic patients with degenerative lumbar stenosis or lumbar spondylolisthesis were recruited. OUTCOME MEASURES The BMDs and BTMs; VAS scores for back and leg, EuroQol Five-Dimension (EQ-5D) scores, Quality of Life Questionnaire of the European Foundation for Osteoporosis-31 (QUALEFFO-31) scores, and Roland-Morris Disability Functioning Questionnaire (RMDQ) scores, complications, and adverse events were assessed at baseline, 6, and 12 months postoperation. METHODS All participants underwent lumbar fusion, received calcium (1200 mg/day) and vitamin D (800 IU/day) supplementation, and were randomized to receive subcutaneous injection of 60 mg denosumab or placebo every 6 months postsurgery. Patients were followed for up to 12 months postoperation. RESULTS We found that denosumab improved BMD of the lumbar, total hip, and femoral neck from baseline by 5.79%, 4.12%, and 4.18% respectively, and also decreased BTMs including P1NP1 and CTX by −45.9% and −47.2% in osteopenia patients after lumbar fusion at the 12-month follow-up. Denosumab improved functional status based on Visual Analogue Scale (VAS) back scores, the Quality of Life Questionnaire of the European Foundation for Osteoporosis-31 (QUALEFFO-31), and the Roland-Morris Disability Functioning Questionnaire (RMDQ) compared with the placebo group at the 12-month follow-up. However, the EuroQol Five-Dimension (EQ-5D) questionnaire and VAS leg scores were not significantly different between the denosumab and placebo groups after 12 months of follow-up. Lastly, no significant difference was observed for the rate of new fractures, reoperation, complications, and adverse events between denosumab and placebo groups at the 12-month follow-up. CONCLUSIONS Ultimately, our data demonstrate that denosumab is effective in protecting against bone loss and maintaining functional status in osteopenic patients after lumbar fusion surgery. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs. Denosumab has been shown to be effective in increasing bone mineral density (BMD) in postmenopausal women with osteoporosis. However, the effect of denosumab on BMD, bone turnover markers (BTMs), and functional status in osteopenic patients after spinal fusion remains unknown. We aimed to investigate the effect of denosumab on BMD of the lumbar, total hip, femoral neck, and BTMs of P1NP1 and CTX. We also aimed to investigate secondary measures post denosumab treatment including Visual Analogue Scale (VAS) and health questionnaire scores, associated complications, and adverse events after lumbar fusion surgery during a 12-month follow-up period. We performed a randomized, double blinded, placebo-controlled clinical trial in osteopenic patients with lumbar degenerative diseases. A total of 76 osteopenic patients with degenerative lumbar stenosis or lumbar spondylolisthesis were recruited. The BMDs and BTMs; VAS scores for back and leg, EuroQol Five-Dimension (EQ-5D) scores, Quality of Life Questionnaire of the European Foundation for Osteoporosis-31 (QUALEFFO-31) scores, and Roland-Morris Disability Functioning Questionnaire (RMDQ) scores, complications, and adverse events were assessed at baseline, 6, and 12 months postoperation. All participants underwent lumbar fusion, received calcium (1200 mg/day) and vitamin D (800 IU/day) supplementation, and were randomized to receive subcutaneous injection of 60 mg denosumab or placebo every 6 months postsurgery. Patients were followed for up to 12 months postoperation. We found that denosumab improved BMD of the lumbar, total hip, and femoral neck from baseline by 5.79%, 4.12%, and 4.18% respectively, and also decreased BTMs including P1NP1 and CTX by −45.9% and −47.2% in osteopenia patients after lumbar fusion at the 12-month follow-up. Denosumab improved functional status based on Visual Analogue Scale (VAS) back scores, the Quality of Life Questionnaire of the European Foundation for Osteoporosis-31 (QUALEFFO-31), and the Roland-Morris Disability Functioning Questionnaire (RMDQ) compared with the placebo group at the 12-month follow-up. However, the EuroQol Five-Dimension (EQ-5D) questionnaire and VAS leg scores were not significantly different between the denosumab and placebo groups after 12 months of follow-up. Lastly, no significant difference was observed for the rate of new fractures, reoperation, complications, and adverse events between denosumab and placebo groups at the 12-month follow-up. Ultimately, our data demonstrate that denosumab is effective in protecting against bone loss and maintaining functional status in osteopenic patients after lumbar fusion surgery.