Abstract: Objective　To investigate the effects of transforaminal lumbar discectomy via contralateral approach on the expression of MMP-3 among patients with sequestered lumbar disc herniation．Methods　One hundred and forty-four cases of sequestered lumbar disc herniation managed in Hebei General Hospital from January 2012 to February 2017 were recruited and randomized into the observation group receiving transforaminal lumbar discectomy via contralateral approach and the control group receiving transforaminal lumbar discectomy via ipsilateral approach with 72 in each.We collected their data about baseline characteristics，value of perioperative indices，Visual Analogue Scale（VAS），MMP-3 expression level，and efficacy evaluation results.Results　Two groups demonstrated no obvious differences in the duration of procedure and intraoperative fluoroscopy times（P>0.05）．The observation group showed lower incidence of complications（cauda equina injury，intervertebral space infection，and dural injury） compared with the control group（P<0.05）．VAS at baseline was similar in both groups（P>0.05），although it was still similar in both groups at 3 months after procedure（P>0.05），it showed a significant decrease in both groups（P<0.05）．At 3 months after procedure，the MMP-3 expression level declined substantially in both groups（P<0.05），and it was much lower in the observation group compared with the control group（P<0.05）．The observation group displayed higher proportion of patients with good to excellent responses to treatment compared to the control group（P<0.05）．Conclusion　For sequestered lumbar disc herniation，transforaminal lumbar discectomy via contralateral approach could improve the outcome by effectively relieving the pain，inhibiting MMP-3 expression level，and reducing the postprocedural incidence of complications without increasing the duration of procedure and intraoperative fluoroscopy times.

Key words: Intervertebral disc displacement, Foraminotomy, Matrix metalloproteinase 3