ObjectiveTo investigate the role of 1,25-dihydroxyvitamin D3 in the posterior transforaminal lumbar interbody fusion (TLIF) for patients with osteoporosis and lumbar degenerative disease. MethodsBetween November 2011 and October 2012,44 patients with osteoporosis and lumbar degenerative disease were treated with TLIF and the clinical data were retrospectively analyzed.The patients were divided into 2 groups based on the administration of 1,25-dihydroxyvitamin D3.After TLIF operation,1,25-dihydroxyvitamin D3 was used in 21 patients (trial group),and was not used in 23 patients (control group).There was no significant difference in gender,age,etiology,affected segment,and disease duration between 2 groups (P>0.05).Lumbar interbody fusion was observed by X-ray and thin-section CT scan reconstruction of lumbar spine according to Brantigan assessment system at 6 months after operation and last follow-up.Clinical outcome was evaluated by Oswestry disability index (ODI) before and after operation. ResultsThe patients of 2 groups were followed up 12-27 months (mean,14.5 months).No fixation loosening or breaking occurred during follow-up.ODI scores in both groups were significantly improved at 6 months after operation and last follow-up (P<0.05) when conpared with preoperative value.Although at preoperation there was no significant difference in ODI score between 2 groups (P>0.05),ODI score of trial group was significantly lower than that of control group at 6 months after operation and last follow-up (P<0.05).At 6 months after operation,the interbody fusion rate was 76.19% (16/21) in trial group and 43.48% (10/23) in control group,showing significant difference (χ2=3.60,P=0.03); at last follow-up,the fusion rate was 95.24% (20/21) in trial group and 65.22% (15/23) in control group,showing significant difference (χ2=4.38,P=0.02). Conclusion1,25-dihydroxyvitamin D3 can improve the lumbar interbody fusion rate and general conditions in the patients with osteoporosis and lumbar degenerative disease.