The Effect of Daily Teriparatide versus One-Time Annually Zoledronic Acid Administration After Transforaminal Lumbar Interbody Fusion in Osteoporotic Patients

PURPOSE: The research aimed to compare the therapeutic effect of teriparatide (TPTD) and zoledronic acid (ZOL) therapy on bone formation and spinal fusion in patients with osteoporosis (OP) who underwent transforaminal lumbar interbody fusion (TLIF). METHODS: On the basis of different anti-OP treatment options, the TPTD group was treated daily with TPTD (20 μg. ih. qd) for at least 6 months, while the ZOL group was treated with a single dose of ZOL (5 mg. ivgtt. st) postoperatively. The visual analogue scale (VAS), Oswestry Disability Index (ODI), bone mineral density (BMD), and concentration of bone turnover markers before, 6, and 12 months after surgery were evaluated. X-ray and three-dimensional computed tomography scans were performed at 6 and 12 months postoperatively to assess interbody fusion. RESULTS: The number of patients in the TPTD and ZOL groups was 29 and 38 patients, respectively. The VAS and ODI scores in both groups were significantly reduced at 6 and 12 months after TLIF. Compared with that of baseline, the lumbar spine BMD of TPTD patients increased significantly from 0.716±0.137 g/cm(2) to 0.745±0.124 g/cm(2) and 0.795±0.123 g/cm(2) at 6 and 12 months, respectively, and was significantly higher than that of the ZOL group at 12 months (0.720±0.128 g/cm(2)). The bone formation marker, P1NP, in the TPTD group increased significantly (145.48±66.64 ng/mL and 119.55±88.27 ng/mL) compared with baseline (44.67±25.15 ng/mL) and in the ZOL group (28.82±19.76 ng/mL and 29.94±20.67 ng/mL) at 6 and 12 months, respectively. The fusion rates in the TPTD and ZOL groups were 57% and 45% at 6 months, without statistical significance. However, TPTD had a more statistically significant positive influence on fusion rate than ZOL at 12 months (86% vs 70%). CONCLUSION: TPTD was more efficient than ZOL in bone formation and spinal fusion in OP patients who underwent TLIF.