| Part Ⅰ Corridor radiological anatomy study of oblique lateral interbodyfusion in lumbar degenerative diseasesObjective To study the radiological parameters of magnetic resonance imaging(MRI)in the surgical corridor of oblique lateral interbody fusion(OLIF)in lumbar degenerative diseases(LDD).Methods On the basis of lumbar spine MRI in supine position(conventional position),the right lateral decubitus(surgical position)was added for 36 LDD patients.According to the presence of lumbar scoliosis in LDD,the patients were divided into non-degenerative lumbar scoliosis(non-scoliosis)group with 15 cases and degenerative lumbar scoliosis group with 21cases(including 11 cases in left convexity group and 10 cases in right convexity group).The anatomical parameters related to the surgical corridor at the axial intervertebral space level of L2-5 segments under the two postures were measured,including the distance between the left psoas major muscle and abdominal aorta / iliac vessels,the angle of the surgical corridor,the distance between the attachment point of psoas major muscle,the percentage of psoas major muscle spanning area,and the ratio of width to thickness of the anterior edge of psoas major muscle.The differences of corridor radiological parameters between the three groups and the influence of right lateral decubitus on the parameters were analyzed.Results There was no statistical difference in the general data of the three groups of patients(P>0.05).(1)The distance between the left psoas muscle and the abdominal aorta/iliac vessels: in the L2-3 segment,the non-scoliosis group(18.6±5.4mm)and the left convex group(17.2±4.1mm)were both smaller than the left concave group(24.5±6.3mm)(P<0.05);in the L3-4 segment,the left convex group(16.3±4.4mm)was smaller than the left concave group(21.3±2.5mm)(P<0.05);in the L4-5 segment,the non-scoliosis group(17.2±6.7mm)and the left concave group(16.4±4.9mm)were smaller than the left convex group(24.7±7.2mm)(P<0.05).The right lateral decubitus reduced the distance of all segments in non-scoliosis group,left convex group and L3-5 segments in left concave group(P<0.05).(2)Angle of surgical corridor: in the L2-5 segments,the left convex group(27.3±7.0°,29.3±8.1°,31.6±5.4°)was smaller than the non-scoliosis group(45.5±6.4°,47.7±4.4°,42.5°±6.9°)(P<0.05).The right lateral decubitus increased the corridor angle of all segments in the non scoliosis group,the left convex group and the L2-4 segments in the left concave group(P<0.05).(3)The distance of the psoas muscle attachment point: in the L2-3segment,the non-scoliosis group(11.2±3.6mm)was larger than the left concave group(6.1±3.4mm)(P<0.05).In L3-5 segments,the left convex group(7.7±2.9mm,4.6±2.7mm)was smaller than the non-scoliosis group group(12.5±3.4mm,10.5±2.7mm)and left concave group(12.1±4.4mm,9.4±3.3mm)(P<0.05).The right lateral decubitus increased the distances of the L2-4 segments in the non-scoliosis group,the left convex group,and the L3-4 segment in the left concave group(P<0.05).(4)Percentage of psoas major muscle spanning area: in the L2-4 segments,the left concave group(9.0±5.6%,17.3±9.8%)was smaller than the non-scoliosis group(25.8±10.4%,28.3±11.1%)and the left convex group(19.2±8.7%,29.2±9.3%)(P<0.05).The right lateral decubitus increased the percentage of all segments in the non-scoliosis group,the L2-4 segments in the left convex group,and the L3-4 segment in the left concave group(P<0.05).(5)The ratio of the width to the thickness of the anterior edge of the psoas major: there was no statistical difference in all segments among the three groups(P>0.05).The ratio of L3-4 segment in non-scoliosis group,L2-4 segments in left concave group and left convex group was reduced in right lateral decubitus.Conclusion There are significant differences in the radiological parameters of OLIF corridor in patients with different types of LDD,and the right lateral decubitus has a significant impact on it.Surgeons need to make targeted adjustments.Part Ⅱ In vitro biomechanical stability study of OLIF combined with different methods of internal fixationObjective Determination of the stability of the novel lateral plate(NLP)in vitro biomechanics.Methods Six fresh calf lumbar specimens(6 months old,L1-L6)were tested for biomechanics in vitro.Through X-ray examination,lumbar fracture,deformity and other diseases were excluded.Soft tissues such as muscle and fat were removed from all specimens,while structures such as ligaments,intervertebral discs,and spinous processes were preserved.The surgical segment was set to L3-4.Each specimen was tested in the following order:(1)intact(INT);(2)stand alone(SA);(3)OLIF combined with lateral instruments(LIs),including lateral screw-rod(LSR),NLP;(4)OLIF combined with pedicle screw-rod(PS),including unilateral PS(UPS),bilateral PS(BPS).The test device is a mechanical machine with 6 degrees of freedom motion.A pure moment of ±7.5Nm is applied to the specimen to generate 6 different motion directions such as flexion and extension,lateral bending,and axial rotation.Record the L3-4 range of motion(ROM).Results Postoperative radiological examination showed that the cage and internal fixation were in a good position and fixed in place.(1)Flexion and extension: ROM of all fixation methods was less than INT(4.15±0.61°)(P<0.05).UPS(0.54±0.16°),BPS(0.52±0.14°)were smaller than SA(1.16±0.22°),LSR(1.05±0.11°),NLP(1.04±0.25°).There was no statistical difference between LSR,NLP and SA(P>0.05).There was no statistical difference between NLP and LSR(P>0.05).There was no statistical difference between UPS and BPS(P>0.05).(2)Lateral bending: ROM of all fixation methods was smaller than INT(5.16±0.63°)(P<0.05).LSR(1.07±0.13°),NLP(1.10±0.16°),UPS(1.04±0.10°),BPS(0.93±0.21°)were smaller than SA(2.42±0.28°)(P<0.05).Compared with LSR and NLP,there was no statistical difference between UPS and BPS(P>0.05).There was no statistical difference between NLP and LSR(P>0.05).There was no statistical difference between UPS and BPS(P>0.05).(3)Rotation: The ROM of all fixation methods was smaller than INT(1.92±0.54°)(P<0.05).LSR(0.93±0.24°),NLP(0.92±0.24°),UPS(0.80±0.22°),BPS(0.74±0.19°)were less than SA(1.50±0.39°)(P<0.05).UPS and BPS were less than LSR and NLP(P<0.05).There was no statistical difference between NLP and LSR(P>0.05).UPS was smaller than BPS(P<0.05).Conclusion The low-notch NLP showed good segmental stability in vitro biomechanics,similar to LSR,and could improve the stability of the surgical segment in all directions of motion,but was weaker than UPS and BPS in flexion-extension and rotation.Part Ⅲ Comparison of clinical efficacy of OLIF combined with different internal fixation methods in the treatment of lumbar degenerative diseasesObjective To compare the efficacy of OLIF combined with different internal fixation methods in the treatment of lumbar degenerative diseases.Methods Retrospective analysis of lumbar degenerative disease patients who received OLIF treatment in our department from June 2017 to June 2021.According to the inclusion criteria,a total of 131 patients(146 segments)were studied.According to different fixation methods,they were divided into stand alone(SA)group with 31 cases,lateral plate(PIVOX)group with 25 cases,unilateral pedicle-screw(UPS)group with 40 cases,and bilateral pedicle-screw(BPS)group with 35 cases.The general data,perioperative parameters,clinical efficacy and radiological parameters of the four groups were compared.Results There was no statistical difference in the general data of the four groups ofpatients(P>0.05).(1)Perioperative parameters: intraoperative blood loss,SA(93.3±65.6m L)and PIVOX(71.7±38.8m L)had no statistical difference(P>0.05);UPS(148.8±68.4m L)and BPS(225.6±108.3m L)was greater than SA and PIVOX(P<0.05);BPS was greater than UPS(P<0.05).Operation time: UPS(182.8±61.8min),BPS(223.6±77.5min)were longer than SA(91.4±20.1min),PIVOX(114.4±45.8min)(P<0.05).Postoperative hospital stay: SA(7.9±2.2d),PIVOX(7.1±2.8d),UPS(8.3±2.4d),and BPS(8.4±3.1d)had no statistical difference(P>0.05).(2)Clinical efficacy score: the visual analog score(VAS)and Oswestry disability index(ODI)of the 4 groups at the last follow-up were significantly lower than those before surgery(P<0.05).At the 3rd month after the operation,the back pain VAS score of BPS was higher than that of other groups(P<0.05).The incidence of complications in SA group(61.3%)was higher than that in PIVOX(24.0%),UPS(25.0%),and BPS(28.6%)(P<0.05).(3)Radiological parameters: postoperative cross-sectional area of dural sac(CSADS)of 4 groups of patients(SA,PIVOX,UPS,BPS)(120.6±32.1mm2,119.8±23.7mm2,121.2±27.1mm2,124.2± 31.6mm2)was significantly larger than preoperative(83.7±26.4mm2,90.4±23.5mm2,83.1±19.7mm2,83.0±22.4mm2)(P<0.05),and postoperative lumbar lordosis(LL)(38.3±9.9°,39.6±13.6°,39.7±12.9°,40.0±12.1°)were significantly higher than those before surgery(35.6±9.9°,36.8±14.2°,37.1±13.8°,37.2±11.9°)(P<0.05).The differences(ΔSL)of segment lordosis(SL)were 1.6±1.8°,3.5±2.0°,2.2±2.5°,4.1±4.3°,of which PIVOX and BPS were greater than SA(P<0.05),and BPS was greater than UPS(P<0.05).The disc height(DH)at the last follow-up in SA(11.3±1.9mm)was not significantly different from that before surgery(8.2±1.9mm)(P>0.05),but the DH at the last follow-up in other groups was higher than that of the surgery.were significantly increased(P<0.05).At the 1st and 3rd month after operation,the DH of BPS(11.9±2.9mm,11.5±2.9mm)was lower than that of PIVOX(14.9±3.0mm,13.9±2.8mm).The fusion rates of the four groups at the last follow-up were 91.4%,88.5%,90.9%,and 87.8%,respectively,and there was no statistical difference between the groups(P>0.05).At the last follow-up,the subsidence rates of SA,PIVOX,UPS,and BPS groups were 41.7%,23.1%,20.5%,and 22.0%,respectively,and there was no statistical difference between the groups(P>0.05).The bone mineral density value of thesubsidence group was lower than that of the non-subsidence group,and at the same time,the endplate damage rate was higher(P<0.05).Conclusion The intraoperative blood loss and operation time of PIVOX are less,and its segmental stability is consistent with that of the posterior pedicle screw.Supplementary internal fixation can better maintain the height of intervertebral space after operation. |
