The application and therapeutic effect of teriparatide after lumbar fusion surgery in patients with osteoporosis

English Keywords:Teriparatide  Osteoporosis  Lumbar fusion  Bone mineral density

English Abstract:

  【Abstract】 Objectives: To explore the application value and clinical efficacy of teriparatide in patients with osteoporosis after lumbar fusion surgery. Methods: A retrospective study was conducted on 131 patients with osteoporosis who underwent posterior single-segment lumbar spondylolisthesis repositioning combined with interbody implant fusion and pedicle screw internal fixation between January 2022 and December 2023. The patients were divided into an observation group(n=69, 37 males and 32 females, 56.03±7.24 years, treated with teriparatide after operation) and a control group(n=62, 37 males and 25 females, 58.72±7.68 years, no teriparatide treatment). Using propensity score matching(PSM) with baseline data as covariates, a caliper value of 0.02 was selected for 1∶1 matching. A total of 60 matched pairs were successfully generated. There was no statistically significant difference between the two groups in baseline characteristics such as age, gender, and BMI after PSM. The operative indexes were compared, including operative duration, intraoperative blood loss, time to the removal of postoperative drainage tube, and length of hospital stay. The modified MacNab criteria were used to evaluate clinical efficacy at 6 months postoperatively of both groups of patients. Before operation, and at 3 months and 6 months after operation, visual analog scale(VAS) score was used to assess the pain conditions, and Oswestry disability index(ODI) was adopted to evaluate lumbar function, meanwhile, hip bone mineral density(BMD) was measured by dual-energy X-ray absorptiometry. Postoperative lumbar CT scans were performed at 3 and 6 months to assess intervertebral fusion rates. The fusion criteria were defined as the presence of continuous trabecular bone formation between the vertebral bodies of the fused segment on both sagittal and coronal CT images. The individual treatment effect(ITE) estimated by the causal forest model was the rate difference in the rate of lumbar spinal fusion in patients applying teriparatide. A binary log-binomial regression model was applied to calculate the relative risk(RR) of postoperative adverse reaction in both groups. Results: There was no significant differences between the two groups in surgical indexes(P>0.05). The excellent and good rates were 93.33% in the observation group and 65.00% in the control group, and the difference between the two groups was statistically significant(P<0.05). Compared with the preoperative values, the low back and leg pain VAS scores and ODI of both groups decreased at 3 and 6 months after operation(P<0.05); Compared with the control group, the low back and leg pain VAS score and ODI of the observation group decreased significantly at 3 and 6 months after operation(P<0.05). The level of hip BMD in the observation group gradually increased at 3 and 6 months after operation compared with the preoperative levels(pre-op: 0.58±0.16g/cm2, post-op 3 months: 0.82±0.21g/cm2, post-op 6 months: 0.91±0.19g/cm2, P<0.05); Compared with the control group, hip BMD in the observation group increased significantly at 3 and 6 months after operation(post-op 3 months: 0.82±0.21g/cm2 vs 0.64±0.19g/cm2, post-op 6 months: 0.91±0.19g/cm2 vs 0.66±0.21g/cm2, P<0.05). The differences in low back and leg pain VAS scores, ODI, and hip BMD group, time, and group×time interaction items were statistically significant(P<0.05). At 3 and 6 months after surgery, the intervertebral fusion rate in the observation group was higher than that in the control group(81.67% vs 60%, 93.33% vs 73.33%, P<0.05). The results of the causal forest model indicated that the ITE values for all 60 patients in the observation group ranged from -0.01 to -0.18(per month), suggesting that the application of teriparatide could enhance lumbar spinal fusion rates, with fusion time potentially reduced by up to approximately 18%. Compared with the control group, patients in the observation group had a lower risk of total incidence of postoperative adverse reactions(RR<1, P<0.05). Conclusions: Teriparatide significantly improves bone quality in patients with osteoporosis, enhances the success rate of intervertebral fusion following lumbar fusion surgery, and effectively shortens fusion time by accelerating the rate of lumbar bone fusion, while demonstrating a favourable safety profile.