Clinical And Three Dimensional Kinematics Study Of TLIF Combined With Unilateral And Bilateral Pedicle Screw Fixation For The Treatment Of Lumbar Degenerative Disc Disease

PART ? Unilateral versus bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion for the treatment of low lumbar degenerative disc diseases:analysis of clinical and radiographic resultsObjective:Our objective was to compare the clinical and radiographic results of unilateral pedicle screw fixation(UPSF)and bilateral pedicle screw fixation(BPSF)after unilateral transforaminal lumbar interbody fusion(TLIF)for the treatment of lumbar degenerative disc diseases(DDD).Methods:63 patients who underwent UPSF or BPSF combined with unilateral TLIF at L4-L5 or L5-S1 were included in our hospital from 2014-2016.The perioperative outcomes and radiographic results were recorded at preoperative and postoperative follow-up.Fusion rates were determined according to the Bridwell-Lenke grading system.Clinical outcomes were evaluated by the VAS,the ODI and the lumbar JOA.Results : According to the perioperative assessments,the operation duration,intra-and postoperative blood loss,painkiller used time,and hospital costs of UPSF group were significantly(p<0.0001)less than the BPSF group.After mean 24 months follow-up,both UPSF and BPSF significantly(p<0.05)maintained the disk height and segmental lordosis of surgical segment and achieve similar clinical outcomes at final follow-up postoperative.The impacts of UPSF on the cranial adjacent vertebra level were significantly(p<0.05)smaller than the BPSF group in the short-term.Conclusion:UPSF techniques with TLIF can attain similar clinical efficiency in treating of low lumbar DDD with single level,compared with BPSF techniques,but UPSF techniques with less surgical injuries and cost.BPSF with TLIF probably cause more degeneration at the cranial adjacent segment,when compared with UPSF techniques.The long term results still need to be observed.PART ? In-vivo dynamic motion characteristics of the lower lumbar spine: L4-5 lumbar degenerative disc diseases undergoing unilateral or bilateral pedicle screw fixation combined with TLIFObjective:To evaluate the short-term in-vivo dynamic motion characteristics of the lower lumbar spine(L3-S1)after UPSF or BPSF combined with TLIF for the treatment of L4-5 lumbar DDD.Methods : 28 patients were recruited.Each patient was scanned with CT to construct 3D models of the L3–S1 vertebrae.Then the dual fluoroscopic imaging system(DFIS)was used to image the low lumbar spines of the patients while they performing seven functional activities.Combined the 3D vertebral models with the dual fluoroscopic imaging,in-vivo vertebral positions were reproduced.The relative ranges of motion(ROM)of L3-4,L4-5 and L5-S1 were analyzed.Results:At L4-5 segment,the primary rotation of the UPSF group(2.11±0.52°)was significantly(p=0.000)more than the BPSF group(0.73±0.32°)at left-right twist.At L3-4 segment,the primary rotation of the UPSF group(2.16±0.73°)showed significantly(p=0.003)less than the BPSF group(3.17±0.88°)at left-right twist,and at left-right bend activity,which was 2.28±1.03°and 3.12±1.04°(p=0.023).However,at L5-S1 segment,there was no significantly difference between the two groups during each posture.Conclusions:The ROM in left-right twisting of UPSF group was significantly larger compared with BPSF group at the operated level in short term.But,UPSF techniques with TLIF have a smaller impact on the cranial adjacent level(L3-4)in left-right twisting and bending activities,when compared with BPSF techniques,which implied that UPSF combined with TLIF would cause less adjacent segment degeneration,still long term study should be performed to confirm.