[Unilateral versus bilateral pedicle screw fixation in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF): a Meta analysis].

Objective: To compare the clinical outcome between unilateral and bilateral pedicle screw fixation in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF) for the treatment of lumbar degenerative diseases.

Methods: The studies concerning unilateral or bilateral pedicle screw fixation in MIS-TLIF for the treatment of lumbar degenerative diseases from January 2000 to October 2015 were searched from Medline, Embase, The Cochrane Library, China Biology Medicinedisc and Wanfang database, China National Knowledge Internet (CNKI). The data of the studies were collected, risk of bias of the included RCTs were assessed according to Cochrane handbook 5.1.0, risk of bias of the included retrospective or prospective studies were assessed according to MINORS. The Oswestry Disability Index (ODI), visual analogue scale(VAS), lumbar lordosis angle, segmental lordosis angle, lumbar scoliosis angle, segmental scoliosis angle, fusion rate, complication rate, hospitalization time, operative time and blood loss data were Meta analyzed by RevMan 5.2.0 software.

Results: Nine studies were included, containing 4 randomized controlled trials (RCT), 2 prospective studies and 3 retrospective studies, there were 451 patients in total. The results showed that there was no significant difference between the two methods in VAS of back pain, VAS of leg pain, ODI, lumbar lordosis angle, segmental lordosis angle, lumbar scoliosis angle, segmental scoliosis angle, fusion rate, complication rate, hospitalization time. There was significant difference in operative time and blood loss between unilateral and bilateral pedicle screw fixation.

Conclusions: Using unilateral or bilateral pedicle screw fixation in MIS-TLIF for lumbar degenerative diseases can achieve the same clinical effects, and there was no significant difference in complication rate. Unilateral pedicle screw fixation is safer than bilateral fixation because of less operative time and blood loss. However, the number and quality of the literatures may result in low reliability, so greater sample size and high quality RCTs are needed in future.