ObjectiveTo investigate the advantage and short- and medium-term effectivenesses of paramedian incision minimally invasive transforaminal lumbar interbody fusion (mini-TLIF) by comparing with open TLIF. MethodsA retrospective analysis was made on the clinical data of 54 patients with single segmental lumbar degenerative disease who accorded with the inclusion criteria between January 2012 and March 2014. Open TLIF was performed in 26 patients (open group), mini-TLIF in 28 cases (minimally invasive group). There was no significant difference in gender, age, disease duration, etiology, and affected segments between 2 groups (P>0.05). The indexes of surgical trauma, systemic inflammatory response, clinical outcome, and interbody fusion rate were compared between 2 groups. ResultsDural rupture occurred in 1 case of open group, L5 nerve root injury in 1 case of minimally invasive group. All patients obtained primary healing of incision. The operation time, intraoperative blood loss, and postoperative drainage of minimally invasive group were significantly lower than those of open group (P<0.05). C-reactive protein, leucocyte count, and creatine kinase-MM (CK-MM) of open group were significantly higher than those of minimally invasive group at 24 hours after operation (P<0.05). At 7 days after operation, the CK-MM of minimally invasive group was significantly lower than that of open group (P<0.05), but no significant difference was found in C-reactive protein and leucocyte count between 2 groups (P>0.05). The follow-up time was 1.2-3.1 years in open group and 1.4-2.9 years in minimally invasive group. At 1 year after operation, the Oswestry disability index (ODI) and visual analogue scale (VAS) scores were significantly improved in 2 groups (P<0.05). Minimally invasive group was better than open group in ODI and VAS score of back pain (P<0.05), but VAS score of leg pain showed no significant difference (P>0.05). According to the Suk interbody fusion standard, solid fusion was obtained in 18 cases, probable fusion in 4 cases, and nonunion in 4 cases, and the fusion rate was 84.61% in open group; solid fusion was obtained in 21 cases, probable fusion in 3 cases, and nonunion in 4 cases, and the fusion rate was 85.71% in minimally invasive group; and the interbody fusion rates showed no significant difference between 2 groups (χ2=0.072, P=0.821). ConclusionCompared with open TLIF, paramedian incision mini-TLIF has advantages of minimal surgical trauma and little blood loss for single-level lumbar degenerative disease. The short- and medium-term effectivenesses are satisfactory.