The trend of changes in spine-pelvic sagittal parameters before and after surgery in patients with double-segment lumbar spondylolisthesis and their evaluating for surgery efficacy / 中国骨伤

OBJECTIVE@#To explore the trend of changes in the parameters of the spine-pelvic sagittal plane before and after surgery in patients with double-segment lumbar spondylolisthesis (LSL) and to evaluate the value of the surgical effect.@*METHODS@#A retrospective analysis of 95 double-segment lumbar spondylolisthesis patients treated with posterior lumbar interbody fusion from October 2019 to October 2020 were analyzed, including 31 males and 64 females;age ranging from 41 to 63 years old, with an average of (52.10±4.35) years old;degree of lesion, 47 patients with gradeⅠand 48 patients with gradeⅡ. The surgical efficacy was evaluated according to the Oswestry dysfunction index(ODI) improvement rate at 3 months after operation. ODI improvement rate ≥50% was considered good, and <50% was considered bad. Ninety-five patients were divided into good curative effect group (74 cases) and poor curative effect group (21 cases) according to surgical curative effect. The clinical data, such as gender, age, body mass index, course of disease, degree of disease, operation time, intraoperative blood loss, and comorbidities were compared between two groups were compared. The parameters of spine pelvis sagittal plane were observed before and 3 months after operation, including spine sacral angle (SSA), T1 pelvic angle (TPA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Clinical symptoms were evaluated using visual analogue scale (VAS) and ODI. The correlation between the changes of spine pelvis sagittal plane parameters and the changes of VAS and ODI before and after surgery were analyzed, and the value of spine pelvis sagittal plane parameters in evaluating the surgical efficacy of patients with double level lumbar spondylolisthesis at 3 months after surgery was evaluated.@*RESULTS@#The courses of disease and surgical time in the group with poor efficacy were longer than those in the group with good efficacy, and the degree of lesion was higher in the group with poor efficacy (P<0.05). The SSA, TPA, LL, and SS of the group with good efficacy were higher than those of the group with poor efficacy before and 3 months after surgery, while the PT was lower than that of the group with poor efficacy (P<0.05). The changes in SSA, TPA, LL, PT, and SS before and after surgery in the group with good efficacy were greater than those in the group with poor efficacy (P<0.05). The VAS and ODI of both groups were lower at 3 months after surgery than before, and the group with good efficacy was lower(P<0.05). The changes in VAS and ODI before and after surgery in the group with good efficacy were greater than those in the group with poor efficacy (P<0.05). The changes in SSA, TPA, LL, PT, SS before and after surgery were positively correlated with the changes in VAS and ODI (P<0.05). Three months after surgery, SSA, TPA, LL, PT, and SS were used to evaluate the surgical efficacy of patients with dual level lumbar spondylolisthesis. The area under the curve (AUC) was 0.868, 0.797, 0.875, 0.822, and 0.853, respectively. The combined evaluation of all indicators resulted in the highest AUC, 0.927, and the best sensitivity and specificity were 90.50% and 91.89%, respectively.@*CONCLUSION@#The spine pelvis sagittal plane parameters SSA, TPA, LL, and SS of patients with double level lumbar spondylolisthesis before and after surgery show an upward trend;PT shows a downward trend;PI do not change significantly. And the changes of SSA, TPA, LL, SS, and PT are closely related to the patient's pain level and the improvement of lumbar function, which can be used as parameters to evaluate the surgical efficacy.

Comparison of screw placement guided by O-arm navigation and ultrasound volume navigation in minimally invasive transforaminal lumbar interbody fusion / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of O-arm navigation and ultrasound volume navigation (UVN) in guiding screw placement during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery.@*METHODS@#Sixty patients who underwent MIS-TLIF surgery for lumbar disc herniation between June 2022 and June 2023 and met the selection criteria were included in the study. They were randomly assigned to group A (screw placement guided by UVN during MIS-TLIF) or group B (screw placement guided by O-arm navigation during MIS-TLIF), with 30 cases in each group. There was no significant difference in baseline data, including gender, age, body mass index, and surgical segment, between the two groups ( P>0.05). Intraoperative data, including average single screw placement time, total radiation dose, and average single screw effective radiation dose, were recorded and calculated. Postoperatively, X-ray film and CT scans were performed at 10 days to evaluate screw placement accuracy and assess facet joint violation. Pearson correlation and Spearman correlation analyses were used to observe the relationship between the studied parameters (average single screw placement time and screw placement accuracy grading) and BMI.@*RESULTS@#The average single screw placement time in group B was significantly shorter than that in group A, and the total radiation dose of single segment and multi-segment and the average single screw effective radiation dose in group B were significantly higher than those in group A ( P<0.05). There was no significant difference in the total radiation dose between single segment and multiple segments in group B ( P>0.05), while the total radiation dose of multiple segments was significantly higher than that of single segment in group A ( P<0.05). No significant difference was found in the accuracy of screw implantation between the two groups ( P>0.05). In both groups, the grade 1 and grade 2 screws broke through the outer wall of the pedicle, and no screw broke through the inner wall of the pedicle. There was no significant difference in the rate of facet joint violation between the two groups ( P>0.05). In group A, both the average single screw placement time and screw placement accuracy grading were positively correlated with BMI ( r=0.677, P<0.001; r=0.222, P=0.012), while in group B, neither of them was correlated with BMI ( r=0.224, P=0.233; r=0.034, P=0.697).@*CONCLUSION@#UVN-guided screw placement in MIS-TLIF surgery demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure. However, it may be influenced by factors such as obesity, which poses certain limitations.

An MRI study of lateral vascular safety zones in oblique lumbar interbody fusion surgery / 中国修复重建外科杂志

OBJECTIVE@#To study the anatomical characteristics of blood vessels in the lateral segment of the vertebral body through the surgical approach of oblique lumbar interbody fusion (OLIF) using MRI imaging, and evaluate its potential vascular safety zone.@*METHODS@#The lumbar MRI data of 107 patients with low back and leg pain who met the selection criteria between October 2019 and November 2022 were retrospectively analyzed. The vascular emanation angles, vascular travel angles, and the length of vessels in the lateral segments of the left vertebral body of L 1-L 5, as well as the distance between the segmental vessels in different Moro junctions of the vertebral body and their distances from the edges of the vertebrae in the same sequence (bottom marked as I, top as S) were measured. The gap between the large abdominal vessels and the lateral vessels of the vertebral body was set as the lateral vascular safe zones of the lumbar spine, and the extent of the safe zones (namely the area between the vessels) was measured. The anterior 1/3 of the lumbar intervertebral disc was taken as the simulated puncture center, and the area with a diameter of 22 mm around it as the simulated channel area. The proportion of vessels in the channel was further counted. In addition, the proportions of segmental vessels at L 5 without a clear travel and with an emanation angel less than 90° were calculated.@*RESULTS@#Except for the differences in the vascular emanation angles between L 4 and L 5, the vascular travel angles between L 1, L 2 and L 4, L 5, and the length of vessels in the lateral segments of the vertebral body among L 1-L 4 were not significant ( P>0.05), the differences in the vascular emanation angles, vascular travel angles, and the length of vessels between the rest segments were all significant ( P<0.05). There was no significant difference in the distance between vessels of L 1, L 2 and L 2, L 3 at Moro Ⅰ-Ⅳ junctions ( P>0.05), in L 3, L 4 and L 4, L 5 at Ⅱ and Ⅲ junction ( P>0.05). There was no significant difference in the vascular distance of L 2, L 3 between Ⅱ, Ⅲ junction and Ⅲ, Ⅳ junction, and the vascular distance of L 3, L 4 between Ⅰ, Ⅱ junction and Ⅲ, Ⅳ junction ( P>0.05). The vascular distance of the other adjacent vertebral bodies was significant different between different Moro junctions ( P<0.05). Except that there was no significant difference in the distance between L 2I and L 3S at Ⅰ, Ⅱ junction, L 3I and L 4S at Ⅱ, Ⅲ junction, and L 2I and L 3S at Ⅲ, Ⅳ junction ( P>0.05), there was significant difference of the vascular distance between the bottom of one segment and the top of the next in the other segments ( P<0.05). Comparison between junctions: Except for the L 3S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ junction, and L 5S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ and Ⅲ, Ⅳ junctions had no significant difference ( P>0.05), there were significant differences in the distance between the other segmental vessels and the vertebral edge of the same sequence in different Moro junctions ( P<0.05). The overall proportion of vessels in the simulated channels was 40.19% (43/107), and the proportion of vessels in L 1 (41.12%, 44/107) and L 5 (18.69%, 20/107) was higher than that in the other segments. The proportion of vessels in the channel of Moro zone Ⅰ (46.73%, 50/107) and zone Ⅱ (32.71%, 35/107) was higher than that in the zone Ⅲ, while no segmental vessels in L 1 and L 2 were found in the channel of zone Ⅲ ( χ 2=74.950, P<0.001). Moreover, 26.17% (28/107) of the segmental vessels of lateral L 5 showed no movement, and 27.10% (29/107) vascular emanation angles of lateral L 5 were less than 90°.@*CONCLUSION@#L 1 and L 5 segmental vessels are most likely to be injured in Moro zones Ⅰ and Ⅱ, and the placement of OLIF channels in L 4, 5 at Ⅲ, Ⅳ junction should be avoided. It is usually safe to place fixation pins at the vertebral body edge on the cephalic side of the intervertebral space, but it is safer to place them on the caudal side in L 1, 2 (Ⅰ, Ⅱ junction), L 3, 4 (Ⅲ, Ⅳ junction), and L 4, 5 (Ⅱ, Ⅲ, Ⅳ junctions).

Comparison of effectiveness between unilateral biportal endoscopic lumbar interbody fusion and endoscopic transforaminal lumbar interbody fusion for lumbar spinal stenosis combined with intervertebral disc herniation / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness between unilateral biportal endoscopic lumbar interbody fusion (ULIF) and endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) in treatment of lumbar spinal stenosis combined with intervertebral disc herniation.@*METHODS@#A clinical data of 64 patients with lumbar spinal stenosis and intervertebral disc herniation, who were admitted between April 2020 and November 2021 and met the selection criteria, was retrospectively analyzed. Among them, 30 patients were treated with ULIF (ULIF group) and 34 patients with Endo-TLIF (Endo-TLIF group). There was no significant difference in baseline data such as gender, age, disease duration, lesion segment, preoperative visual analogue scale (VAS) score of low back pain and leg pain, Oswestry disability index (ODI), spinal canal area, and intervertebral space height between the two groups ( P>0.05). The operation time, intraoperative blood loss, hospital stays, and postoperative complications were compared between the two groups, as well as the VAS scores of low back pain and leg pain, ODI, and imaging measurement indicators (spinal canal area, intervertebral bone graft area, intervertebral space height, and degree of intervertebral fusion according to modified Brantigan score).@*RESULTS@#Compared with the Endo-TLIF group, the ULIF group had shorter operation time, but had more intraoperative blood loss and longer hospital stays, with significant differences ( P<0.05). The cerebrospinal fluid leakage occurred in 2 cases of Endo-TLIF group and 1 case of ULIF group, and no other complication occurred. There was no significant difference in the incidence of complications between the two groups ( P>0.05). All patients in the two groups were followed up 12 months. The VAS scores of lower back pain and leg pain and ODI in the two groups significantly improved when compared with those before operation ( P<0.05), and there was no significant difference between different time points after operation ( P>0.05). And there was no significant difference between the two groups at each time point after operation ( P>0.05). Imaging examination showed that there was no significant difference between the two groups in the change of spinal canal area, the change of intervertebral space height, and intervertebral fusion rate at 6 and 12 months ( P>0.05). The intervertebral bone graft area in the ULIF group was significantly larger than that in the Endo-TLIF group ( P<0.05).@*CONCLUSION@#For the patients with lumbar spinal stenosis combined with intervertebral disc herniation, ULIF not only achieves similar effectiveness as Endo-TLIF, but also has advantages such as higher decompression efficiency, flexible surgical instrument operation, more thorough intraoperative intervertebral space management, and shorter operation time.

Research progress on the influence of Modic changes on lumbar interbody fusion and its treatment measure / 中国修复重建外科杂志

OBJECTIVE@#To review the research progress of Modic changes and its influence on lumbar interbody fusion.@*METHODS@#The domestic and foreign literature related to Modic changes and its influence on lumbar interbody fusion was extensively reviewed. The etiology of Modic changes was summarized, and the treatment measures of Modic changes on lumbar interbody fusion were discussed.@*RESULTS@#The etiology of Modic changes is not clear, which may be related to mechanical factors, autoimmune factors, low toxic infection factors, and genetic factors. Modic changes may lead to fusion failure and cage subsidence after lumbar interbody fusion. Preoperative evaluation of endplate sclerosis, reduction of iatrogenic endplate injury, fine operating of intervertebral space, management of osteoporosis, and selection of appropriate cage can prevent or reduce fusion failure or cage subsidence.@*CONCLUSION@#Modic changes may lead to fusion failure and cage subsidence after lumbar interbody fusion, and active perioperative intervention of Modic changes is helpful to improve the clinical prognosis.

Effectiveness analysis of posterolateral approach lumbar interbody fusion assisted by one-hole split endoscope for L4, 5 degenerative lumbar spondylolisthesis / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of posterolateral approach lumbar interbody fusion assisted by one-hole split endoscope (OSE) and traditional posterior lumbar interbody fusion (PLIF) in the treatment of L4, 5 degenerative lumbar spondylolisthesis (DLS).@*METHODS@#The clinical data of 58 patients with DLS who met the selection criteria admitted between February 2020 and March 2022 were retrospectively analyzed, of which 26 were treated with OSE-assisted posterolateral approach lumbar interbody fusion (OSE group) and 32 were treated with PLIF (PLIF group). There was no significant difference between the two groups in terms of gender, age, body mass index, Meyerding grade, lower limb symptom side, decompression side, stenosis type, and preoperative low back pain visual analogue scale (VAS) score, leg pain VAS score, Oswestry disability index (ODI), and the height of the anterior and posterior margins of the intervertebral space (P>0.05). The operation time, intraoperative blood loss, postoperative hospital stay, and complications were compared between the two groups. The low back pain and leg pain VAS scores and ODI before operation, at 1 month, 6 months after operation, and last follow-up, the height of anterior and posterior margins of the intervertebral space before operation, at 6 months after operation, and last follow-up, the modified MacNab criteria at last follow-up after operation were used to evaluate the effectiveness; and the Bridwell method at last follow-up was used to evaluate the interbody fusion.@*RESULTS@#Both groups successfully completed the operation. Compared with the PLIF group, the OSE group showed a decrease in intraoperative blood loss and postoperative hospital stay, but an increase in operation time, with significant differences (P<0.05). In the OSE group, no complication such as nerve root injury and thecal sac tear occurred; in the PLIF group, there were 1 case of thecal sac tear and 1 case of epidural hematoma, which were cured after conservative management. Both groups of patients were followed up 13-20 months with an average of 15.5 months. There was no complication such as loosening, sinking, or displacement of the fusion cage. The low back pain and leg pain VAS scores, ODI, and the height of anterior and posterior margins of the intervertebral space at each time point after operation in both groups were significantly improved when compared with those before operation (P<0.05). Except for the VAS score of lower back pain in the OSE group being significantly better than that in the PLIF group at 1 month after operation (P<0.05), there was no significant difference in all indicators between the two groups at all other time points (P>0.05). At last follow-up, both groups achieved bone fusion, and there was no significant difference in Bridwell interbody fusion and modified MacNab standard evaluation between the two groups (P>0.05).@*CONCLUSION@#OSE-assisted posterolateral approach lumbar interbody fusion for L4, 5 DLS, although the operation time is relatively long, but the postoperative hospitalization stay is short, the complications are few, the operation is safe and effective, and the early effectiveness is satisfactory.

Biomechanical Analysis on NiTi Memory Alloy Stent for Lumbar Interbody Fusion / 医用生物力学

Objective To evaluate biomechanical properties of the nickel-titanium (NiTi) memory alloy stent and its in vitro biomechanical properties for lumbar interbody fusion. Methods The mechanical properties of the NiTi memory alloy stent were tested on mechanical testing machine. Moreover, lumbar interbody fusion was simulated on fresh lumbar specimens, and biomechanical properties of the NiTi memory alloy stent with matching bone graft for used for lumbar interbody fusion were analyzed and compared with the traditional box-shape cage. Results The maximum compressive strength of the NiTi memory alloy stent was ( 12 964 ± 962) N. The maximum deformation within the effective range of memory characteristics was (4. 68±0. 03) mm. The recovery rate of the NiTi memory alloy stent was up to 99. 86% . Compared with the intact lumbar model, the stability of the operative segment after the simulated lumbar interbody fusion using NiTi memory alloy stent alone was increased in the direction of anterior flexion, posterior extension, lateral flexion and rotation, which was equivalent to the box shape cage group (P>0. 05). After the combined use of autogenous bone granule and absorbable bone cement the ROM of the operative segment was further reduced (P0. 05). The pull-out strength of the NiTi memory alloy stent with matching bone graft group was significantly stronger than that of the box-shape cage group (P<0. 05). Conclusions The NiTi memory alloy stent in this study was designed with a matched bone granule-absorbable bone cement graft,which provided a new idea for the further optimization and development of lumbar interbody fusion. With excellent support and deformation properties, this NiTi memory alloy stent is biomechanical equivalent to the traditional box shape cage for lumbar interbody fusion, and can greatly improve the stability of surgical segment and the pull-out strength of implants after the combined use of autogenous bone granule and absorbable bone cement.

Biomechanical Evaluation of Oblique Lateral Interbody Fusion Combined with Different Internal Fixation Methods for Treating Degenerative Lumbar Scoliosis:A Finite Element Analysis / 医用生物力学

Objective To verify the biomechanical stability of oblique lateral interbody fusion ( OLIF) combinedwith different fixation methods for treating degenerative lumbar scoliosis (DLS) by three-dimensional (3D) finite element analysis. Methods The L1-S1 3D finite element DLS model ( Model 1) was established, and then the OLIF (L2-5) at 3 contiguous levels of fusion and its combination with different internal fixation methods were simulated, namely, stand-alone OLIF model ( Model 2), vertebral screw fixation model ( Model 3), unilateral pedicle screw fixation model (Model 4) and bilateral pedicle screw fixation model (Model 5) were established,respectively. Under upright, flexion, extension, lateral bending and axial rotation states, range of motion (ROM) of fusion segments, as well as cage stress, internal fixation stress, and stress distribution were recorded and analyzed. Results Under six motion states, the overall ROM of fusion segments in Models 2-5 was smaller than that of Model 1. Compared with Model 1, the overall ROM reduction of Model 3 and Model 4 was larger than that of Model 2 and smaller than that of Model 5. Under flexion and extension, the overall ROM reduction of Model 4 and Model 5 was basically equal. Under left and right lateral bending, the overall ROM reduction of Model 3 and Model 5 was basically equal. Under all motion states, the peak stress of Model 3 and Model 4 fusion cage was larger than that of Model 5 and smaller than that of Model 2. The peak stresses of L2-3, L3-4 and L4-5 fusion cages in Model 3 increased by 5. 52% , 10. 96% and 7. 99% respectively compared with Model 5 under left lateral bending, and the peak stresses of L2-3, L3-4 and L4-5 fusion cages in Model 4 increased by 8. 70% , 7. 00% and 6. 99% respectively under flexion. Under all motion states, the peak stress of screw rod in Model 5 was smaller than that of Model 3 and Model 4, and the peak stresses of screw rod in Models 3-5 were the smallest in upright state. Conclusions The OLIF with unilateral pedicle screw fixation or vertebral screw fixation can provide favorable biomechanical stability of the fusion segment. The results provide some references for clinical application of OLIF technology in the treatment of DLS.

Effect of neuroelectrophysiological changes on the clinical manifestations and surgical outcomes of lumbar degenerative diseases / 中国骨伤

OBJECTIVE@#To evaluate the effects of electromyography on the clinical manifestations and prognosis after posterior lumbar interbody fusion(PLIF) of degenerative lumbar diseases.@*METHODS@#A retrospective analysis was performed on 68 patients with degenerative lumbar diseases, including 29 males and 39 females, aged 21 to 84 years old, who underwent electromyogram (EMG) from January 2018 to October 2019. The patients were divided into negative and positive groups according to whether theresults of EMG was normal or abnormal, PLIF surgery was performed in both groups. The preoperative duration of illness, postoperative recovery time, operative time, intraoperative blood loss, postoperative ambulation time and length of postoperative hospital stay were recorded. The clinical efficacy was evaluated by visual analogue scale(VAS) of low back and lower limb, the Japanese Orthopedic Association(JOA) score before and after operation.@*RESULTS@#All patients were follow-up from 26 to 39 months. The subjective symptoms, clinical signs, daily activities and JOA total scores after operation in two groups were significantly higher than those before preoperation(P<0.05);the clinical signs score and total JOA score in the negative group at 3 months after operation were higher than those in the positive group(P<0.05). The VAS score of leg pain in the negative group after 1 and 3 months was less than that in the positive group(P<0.05). Patients 's illness time, postoperative recovery time, hospitalization time and implantation time in the negative group were shorter than those in the positive group(P<0.05). At other time points, there was no significant difference in low pain VAS, leg pain VAS, JOA scores in the two groups(P>0.05). There was no significant difference in the operation time and intraoperative bleeding volume between the two groups(P>0.05).@*CONCLUSION@#Patients with normal electromyography had shorter disease duration than ones with abnormal electromyography in lumbar degenerative disease;after PLIF, patients with normal electromyography recovered faster than ones with abnormal electromyography, but the results of electromyography had no effect on the final prognosis of PLIF surgery.

Causes of asymptomatic side limb pain after minimally invasive transforaminal lumbar interbody fusion / 中国骨伤

OBJECTIVE@#To investigate possible causes and preventive measures for asymptomatic pain in the limbs after minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF).@*METHODS@#Clinical data from 50 patients with lumbar degenerative disease who underwent MIS-TLIF between January 2019 and September 2020 were retrospectively analyzed. The group included 29 males and 21 females aged from 33 to 72 years old, with an average age of (65.3±7.13) years. Twenty-two patients underwent unilateral decompression, and 28 underwent bilateral decompression. The side(ipsilateral or contralateral) and site(low back, hip, or leg) of the pain were recorded before surgery, 3 days after surgery, and 3 months after surgery. The pain degree was evaluated using the visual analogue scale(VAS) at each time point. The patients were further grouped based on whether contralateral pain occurred postoperatively (8 cases in the contralateral pain group and 42 in the no contralateral pain group), and the causes and preventive measures of pain were analyzed.@*RESULTS@#All surgeries were successful, and the patients were followed up for at least 3 months. Preoperative pain on the symptomatic side improved significantly, with the VAS score decreasing from (7.00±1.79) points preoperatively to (3.38±1.32) points at 3 days postoperatively and (3.98±1.17) points at 3 months postoperatively. Postoperative asymptomatic side pain (contralateral pain) occurred in 8 patients within 3 days after surgery, accounting for 16% (8/50) of the group. The sites of contralateral pain included the lumbar area (1 case), hip(6 cases), and leg (1 case). The contralateral pain was significantly relieved 3 months after surgery.@*CONCLUSION@#More cases of contralateral limb pain occur after unilateral decompression MIS-TLIF, and the reason may include contralateral foramen stenosis, compression of medial branches, and other factors. To reduce this complication, the following procedures are recommended: restoring intervertebral height, inserting a transverse cage, and withdrawing screws minimally.

Comparison of clinical effect and muscle injury imaging between oblique lateral lumbar interbody fusion and transforaminal lumbar interbody fusion in the treatment of single-segment degenerative lumbar spinal stenosis / 中国骨伤

OBJECTIVE@#To compare the efficacy and muscle injury imaging between oblique lateral lumbar interbody fusion (OLIF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of single-segment degenerative lumbar spinal stenosis.@*METHODS@#The clinical data of 60 patients with single-segment degenerative lumbar spinal stenosis who underwent surgical treatment from January 2018 to October 2019 was retrospectively analyzed. The patients were divided into OLIF groups and TLIF group according to different surgical methods. The 30 patients in the OLIF group were treated with OLIF plus posterior intermuscular screw rod internal fixation. There were 13 males and 17 females, aged from 52 to 74 years old with an average of (62.6±8.3) years old. And 30 patients in the TLIF group were treated with TLIF via the left approach. There were 14 males and 16 females, aged from 50 to 81 years old with an average of (61.7±10.4) years old. General data including operative time, intraoperative blood loss, postoperative drainage volume, and complications were recorded for both groups. Radiologic data including disc height (DH), the left psoas major muscle, multifidus muscle, longissimus muscle area, T2-weighted image hyperintensity changes and interbody fusion or nonfusion were observed. Laboratory parameters including creatine kinase (CK) values on postoperative 1st and 5th days were analyzed. Visual analogue scale(VAS) and Oswestry disability index(ODI) were used to assess clinical efficacy.@*RESULTS@#There was no significant difference in the operative time between two groups(P>0.05). The OLIF group had significantly less intraoperative blood loss and postoperative drainage volume compared to the TLIF group(P<0.01). The OLIF group also had DH better recovery compared to the TLIF group (P<0.05). There were no significant differences in left psoas major muscle area and the hyperintensity degree before and after the operation in the OLIF group (P>0.05). Postoperativly, the area of the left multifidus muscle and longissimus muscle, as well as the mean of the left multifidus muscle and longissimus muscle in the OLIF group, were lower than those in the TLIF group (P<0.05) .On the 1st day and the 5th day after operation, CK level in the OLIF group was lower than that in the TLIF group(P<0.05). On the 3rd day after operation, the VAS of low back pain and leg pain in the OLIF group were lower than those in the TLIF group (P<0.05). There were no significant differences in the ODI of postoperative 12 months, low back and leg pain VAS at 3, 6, 12 months between the two groups(P>0.05). In the OLIF group, 1 case of left lower extremity skin temperature increased after the operation, and the sympathetic chain was considered to be injured during the operation, and 2 cases of left thigh anterior numbness occurred, which was considered to be related to psoas major muscle stretch, resulting in a complication rate of 10% (3/30). In the TLIF group, one patient had limited ankle dorsiflexion, which was related to nerve root traction, two patients had cerebrospinal fluid leakage, and the dural sac was torn during the operation, and one patient had incision fat liquefaction, which was related to paraspinal muscle dissection injury, resulting in a complication rate of 13% (4/30). All patients achieved interbody fusion without cage collapse during the 6- month follow-up.@*CONCLUSION@#Both OLIF and TLIF are effective in the treatment of single-segment degenerative lumbar spinal stenosis. However, OLIF surgery has obviously advantages, including less intraoperative blood loss, less postoperative pain, and good recovery of intervertebral space height. From the changes in laboratory indexes of CK and the comparison of the left psoas major muscle, multifidus muscle, longissimus muscle area, and high signal intensity of T2 image on imaging, it can be seen that the degree of muscle damage and interference of OLIF surgery is lower than that of TLIF.

Early efficacy of full endoscopic lumbar interbody fusion in the treatment of lumbar degenerative diseases with lumbar instability / 西安交通大学学报(医学版)

【Objective】 To investigate the early clinical efficacy of full endoscopic lumbar interbody fusion in the treatment of lumbar degenerative diseases with lumbar instability. 【Methods】 We made a retrospective analysis of 22 cases of lumbar degenerative diseases with lumbar instability treated by full endoscopic lumbar interbody fusion in Department of Orthopedics， Tangdu Hospital of Air Force Military Medical University from January 2019 to June 2020. The operation time， intraoperative bleeding volume， and hospital stay were recorded. The Visual Analogue Scale （VAS） for lower back pain and leg pain and Oswestry disability index （ODI） were compared before operation， 1 week， 1 month， 3 months， 6 months and at the last follow-up after operation. Modified MacNab was used to evaluate the clinical efficacy at the last follow-up. 【Results】 Operations on the 22 patients were all completed successfully. The average operation time was （206.59±5.69） min （with the range of 180-240 min）； the average volume of intraoperative bleeding was （92.73±22.29） mL （with the range of 50-120 mL）； the average hospitalization time was （8.82±1.53） d （with the range of 7-13 d）. All the patients were followed up for an average of （10.95±3.34） months （with the range of 6-18 months）. The VAS score and ODI at each time point after surgery were significantly decreased compared with those before operation （P<0.05）. The modified MacNab used to evaluate the clinical efficacy at the last follow-up showed that the total excellent and good rate was 90.91%， including 17 cases of excellence， 3 cases of good， and 2 cases of fair. 【Conclusion】 The early clinical effect of full endoscopic lumbar interbody fusion in the treatment of lumbar degenerative diseases with lumbar instability is satisfactory.

Clinical practice of percutaneous full-endoscopic modified posterior lumbar interbody fusion combined with pedicle screw fixation through paraspinal muscle clearance / 西安交通大学学报(医学版)

【Objective】 To study the clinical practice and early outcome of percutaneous full-endoscopic modified posterior lumbar interbody fusion（mPLIF）combined with pedicle screw fixation through paraspinal muscle clearance. 【Methods】 A retrospective study was conducted to analyze the clinical data of patients with lower lumbar spinal diseases treated from May 2019 to April 2020. All the enrolled patients received mPLIF combined with pedicle screw fixation through paraspinal muscle clearance. The follow-up period was more than 1 year； the general parameters included age， gender， duration of disease， diagnosis of disease， surgery segment， and postoperative hospitalization time. Operation parameters included operation time and blood loss. We obtained the clinical parameters such as visual analogue scale （VAS） score for back and lower extremity， Oswestry disability index （ODI） score， and Macnab satisfaction score at the last follow-up. We evaluated the imaging parameters including intervertebral disc height， segmental lordosis angle， lumbar lordosis angle， as well as fusion outcome of patients with single segmental lumbar disease. In addition， intraoperative and postoperative complications were recorded. 【Results】 Totally 18 patients met the inclusion criteria， among whom 8 were male and 10 were female， with the average age of （53.3±8.3） years old and the average duration of disease being （28.9±36.6） months. Among them 16 patients were diagnosed as lumbar degenerative disease and the other 2 had lumbar disc infection. One patient received L3-L4 and L4-L5 intervertebral fusion； the others had one-segmental fusion， among which 11 cases were L4-L5 and 6 cases were L5-S1. The average operation time was （207.8±31.7） min， and the average blood loss was （25.6±7.8） mL， and the mean postoperative hospitalization time was （6.56±2.30） days. VAS scores of back and lower extremities at postoperative 1 week， 6 months and the last follow-up were statistically significantly improved from the preoperative scores. ODI scores at postoperative 6 months and the last follow-up were also statistically significantly improved. The rate of excellent and good according to the Macnab criteria was 94.4%. For the 17 single-level fusion patients， intervertebral height was significantly higher postoperatively and at the last follow-up compared with that of the preoperative one （P<0.05）. Segmental lordosis angle was bigger postoperatively and at the last follow-up （P>0.05）， which was not statistically significant. Lumbar lordosis angle was significantly bigger postoperatively （P<0.05） and bigger at the last follow-up， but with no statistical significance （P>0.05）. The fusion rate at the last follow-up was 88.2%. The cage broke in the process of implantation in one patient. A cage retroposition occurred in one patient at the follow-up. 【Conclusion】 Percutaneous full-endoscopic modified posterior lumbar interbody fusion combined with pedicle screw fixation through bilateral paraspinal muscle clearance by one incision showed excellent clinical outcomes in treating many kinds of lower lumbar diseases. This operation should be an excellent option for lower lumbar fusion.

Clinical application and research progress of OLIF / 西安交通大学学报(医学版)

Oblique lumbar interbody fusion （OLIF） is an internationally popular and innovative technique for treating various lumbar diseases. Introduced to China in 2014， it has been widely used to treat lumbar spine diseases. Advances in biomechanical theory and new instruments have broadened the indications for OLIF surgery and reduced its learning curve. The development of standalone OLIF makes OLIF more minimally invasive. The improvement of localized surgical methods based on Chinese anatomical studies makes OLIF more suitable for Chinese patients. The development of L5/S1 OLIF technology has expanded the application range of OLIF. This paper reviews the clinical application and research progress of OLIF.

Effects of posterior pedicle screw internal fixation on early Cage subsidence after oblique lateral lumbar interbody fusion / 西安交通大学学报(医学版)

【Objective】 To investigate the effects of one-stage additional posterior pedicle screws （PPS） internal fixation on early Cage subsidence after oblique lateral interbody fusion （OLIF）. 【Methods】 We made a retrospective analysis of 118 patients with lumbar degenerative diseases treated with OLIF at the Department of Orthopedics， Sir Run Run Shaw Hospital， School of Medicine， Zhejiang University， from January 2016 to December 2019. We divided the patients into OLIF stand-alone group （58 ones） and OLIF with PPS fixation group （60 ones） according to the surgical procedure. All the patients had preoperative frontal and lateral radiographs of the lumbar spine， and CT and MR scans were performed. The clinical outcomes and reoperation rates of the two groups were compared at immediate postoperative follow-up and at 1， 3， 6 and 12 months. X-ray and CT examinations were performed to assess Cage subsidence in both groups at each postoperative follow-up. 【Results】 There was no statistical difference between the two groups in baseline data and surgical segmentation. Of the 118 patients with 141 discs who underwent OLIF surgery， 58 patients with 68 discs received OLIF stand-alone surgery and 60 ones with 73 discs received OLIF with PPS fixation. There were no significant differences in intraoperative bleeding， complications， or postoperative clinical outcomes between the two groups （P>0.05）， and the Cage subsidence rate was 22.4% in OLIF stand-alone group and 5% in OLIF with PPS fixation group， with significant difference between the two groups （P<0.01）. 【Conclusion】 Both OLIF stand-alone and OLIF additional PPS fixation can achieve good early clinical outcomes， and first-stage additional PPS fixation can significantly reduce the occurrence of Cage subsidence in the early postoperative period after OLIF.

Comparison of clinical efficacy and sagittal parameters of two minimally invasive surgical methods in treating degenerative lumbar spondylolisthesis / 西安交通大学学报(医学版)

【Objective】 To compare the clinical efficacy and sagittal parameters of oblique lateral interbody fusion （OLIF） combined with posterior percutaneous internal fixation and percutaneous transforaminal endoscope-assisted posterior lumbar interbody fusion （PT-Endo-TLIF） in treating degenerative lumbar spondylolisthesis. 【Methods】 A retrospective analysis was made on 43 patients with Meyerding Ⅰ and Ⅱ° degenerative lumbar spondylolisthesis treated in our hospital from September 2017 to January 2020. Among them 23 cases were treated by OLIF， and the other 20 cases were treated by PT-Endo-TLIF. We observed and recorded the operation time， average length of hospital stay， and intraoperative blood loss， and postoperative complications of the patients. The patients were followed up 3 day， 6 and 12 months after the operation. The lumbar sagittal parameters of the two groups were compared by X-ray， CT and MRI examinations. The patients’ lower back pain was recorded for visual analogue scale （VAS）， and Oswestry disability index （ODI） was used to evaluate the clinical efficacy. 【Results】 Both groups of patients successfully completed the operation and follow-up， with the average follow-up time of 12 months. The average amount of intraoperative blood loss and operation time were significantly lower in OLIF group than in PT-Endo-TLIF group （P<0.05）. Intervertebral height increased significantly in the two groups after operation compared with pre-operation （P<0.05）. Compared with pre-operation， lumbar lordosis angle， lower lumbar lordosis angle and lumbar lordosis distribution index increased in both groups （P<0.05）， with no significant difference between them （P>0.05）. The inclination angle of L4 vertebral body and the distance between L1 vertical line and S1 in both groups were decreased compared with those before surgery （P<0.05）， but there was no significant difference between the two groups （P>0.05）. The inclination angle of L5 vertebral body in the two groups was increased compared with that before surgery （P<0.05）， but there was no statistical significance between both groups （P>0.05）. 【Conclusion】 OLIF surgical technique has the comparative advantages of definite curative effect， less trauma， fewer surgical complications， shorter operation time， less bleeding， and good recovery of the height of intervertebral space， which is suitable for its application among clinicians.

Clinical effects of treatment of single-segment lumbar tuberculosis by oblique lateral interbody fusion and percutaneous pedicle screw fixation / 西安交通大学学报(医学版)

【Objective】 To investigate the clinical effects of treatment of single-segment lumbar tuberculosis by oblique lateral interbody fusion with autologous iliac bone and percutaneous pedicle screw fixation. 【Methods】 We collected the clinical data of 47 patients with lumbar tuberculosis treated in The First Affiliated Hospital of Xi’an Jiaotong University from March 2017 to January 2020. Among them， 22 patients underwent oblique lateral interbody fusion with autologous iliac bone and percutaneous pedicle screw fixation （minimally invasive group） and 25 patients underwent open surgery combined anterior-debridement and posterior-fixation （control group）. The related data were collected， including gender， sex， body mass index （BMI）， systemic symptoms of tuberculosis， operation duration， intraoperative bleeding， postoperative drainage， hospital stay， complications， visual analogue score （VAS）， erythrocyte sedimentation rate （ESR）， and Oswestry disability index （ODI）. 【Results】 Baseline clinical characteristics did not significantly differ between the two groups （P>0.05）. Compared with control group， the minimally invasive group had shorter operation duration ［（188.64±18.59） min vs. （201.60±22.67） min］， less intraoperative blood loss ［（118.64±22.95） mL vs. （553.60±100.54） mL］， less postoperative drainage ［（134.55±36.48） mL vs. （291.20±61.53） mL］， and shorter hospitalization time ［（12.86±2.17） d vs. （15.80±3.03） d］ （all P0.05）. Compared with the preoperative ones， ESR， VAS score and ODI score significantly decreased and Cobb angle significantly increased in both groups （all P0.05）. 【Conclusion】 Both minimally invasive technique and open surgery can achieve excellent clinical results， but the minimally invasive technique can reduce the surgical trauma and shorten the hospitalization time.

Clinical effects of robot-assisted minimal invasive transforaminal lumbar interbody fusion in the treatment of single-segment lumbar disc herniation / 西安交通大学学报(医学版)

【Objective】 To compare the clinical effects and screw placement accuracy for treating lumbar disc herniation between robot-assisted minimal invasive transforaminal lumbar interbody fusion (RA-MIS-TLIF) and minimal invasive transforaminal lumbar interbody fusion (MIS-TLIF). 【Methods】 We retrospectively recruited 69 patients with single segment lumbar disc herniation treated between January 2018 and August 2019 at Honghui Hospital of Xi’an Jiaotong University. There were cases of 33 RA-MIS-TLIF (RA group) and 36 MIS-TLIF (MIS-TLIF group). Subsequently, the patients’ baseline characteristics were collected, including age, gender, body mass index, complication with diabetes, duration of symptoms, operated segment, and follow-up time. We also collected perioperative parameters such as operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, screw placement accuracy, wound drainage, hospitalization duration, postoperative complicatins, and fusion rate. Lower back pain, lower extremity pain visual analogue score (VAS), and lumbar Japanese Orthopaedic Association Scores (JOA) were obtained preoperatively, postoperative 3 days/6 months/12 months, and the last follow-up. 【Results】 All the procedures were successfully completed and the follow-up time was 14.82±1.83 (RA group) and 15.11±1.62 (MIS-TLIF group) months, without significant difference (P>0.05). Compared with MIS-TLIF group, RA group had less intraoperative blood loss [(116.67±18.48) min vs. (128.06±22.53) min], fluoroscopy frequency [(12.42±2.28) vs. (15.67±2.46)], screw placement accuracy (93.18% vs. 84.03%), postoperative drainage [(73.03±23.52) mL vs. (88.33±28.54) mL], and shorter hospitalization stay [(6.45±1.52)d vs. (7.69±1.85) d] (all P0.05). The VAS of lower back pain and lower extremity pain, and lumbar JOA were significantly improved after the operation (P0.05). Meanwhile, fusion rate and incidence of complications did not significantly differ between the two groups (P>0.05). 【Conclusion】 Both robot-assisted MIS-TLIF and MIS-TLIF can achieve excellent clinical effects in treating single-segment lumbar disc herniation. However, the former can improve the accuracy of screw placement and reduce intraoperative blood loss, fluoroscopy frequency, postoperative drainage and hospitalization time, which indicates a promising application.

Biomechanical Characteristics of Lumbar Fusion by Three Internal Fixation Methods / 医用生物力学

Objective To analyze the biomechanical characteristics of lumbar fusion by 3 internal fixation methods using three-dimensional (3D) finite element (FE) method. Methods The FE fixation models of physiological L4-5, unfixed fusion L4-5, translaminar facet screw (TLFS), lumbar pedical screw+translaminar facet screw (LPS+TLFS), bilateral pedical screw (BPS) with complete osteotomy or partial osteotomy of facet joint were established, respectively. The biomechanical characteristics of L4 centrum and implants under six motion states (spinal flexion, extension, lateral bending and axial rotation) in L4-5 fusion model and three fixation models were compared by FE analysis. Results The average maximal displacements of L4 centrum in L4-5 unfixed fusion model, TLFS model, TLFS+LPS model, BPS model were 1.410 8, 0.629 8, 0.336 9, 0.252 8 mm (complete osteotomy of facet joint) and 1.296 7, 0.844 9, 0.340 9, 0.273 8 mm (partial osteotomy of facet joint); the average maximal displacements of cage were 0.479 9, 0.319 5, 0.167 6, 0.126 4 mm (complete osteotomy of facet joint) and 0.378 7, 0.348 4, 0.183 5, 0.137 2 mm (partial osteotomy of facet joint)；the average maximum stresses of screws and rods during 6 motions in TLFS model, TLFS+LPS model, BPS model were 178.34, 79.55, 56.33 MPa (complete osteotomy of facet joint) and 142.29, 103.02, 59.69 MPa (partial osteotomy of facet joint). Conclusions In percutaneous transforaminal lumbar interbody fusion, the fixation effect of BPS model was similar to that of LPS+TLFS model. BPS model could achieve the best spinal stability, and LPS+TLFS model was also a good fixation method. The stability of TLFS model alone was relatively poor, but it was still better than that of cage bone graft without internal fixation. In the absence of internal fixation, preservation of the articular process significantly increased stability of the spine.

Biomechanical Study of Novel Articular Process Fixation System Combined with Unilateral Pedicle Screw Fixation / 医用生物力学

Objective To study the stability of lumbar spine after transforaminal lumbar interbody fusion (TLIF) surgery combined with a novel articular process fixation system (APFS). Methods Based on the validated finite element model of L3-S1 intact segment (Model A), TLIF surgery was simulated to establish bilateral pedicle screw TLIF model (Model B), right unilateral pedicle screw TLIF model (Model C), APFS combined with right pedicle screw fixation TLIF model (Model D). The range of motion (ROM) of the lumbar spine model and stress distributions on pedicle screws, APFS and interbody fusion cages under different working conditions were observed. Results The overall ROMs of Models B, C, and D under different working conditions were comparable, which were all smaller than those of the physiological model. Compared with Models B and C, the maximum compressive stress of the right pedicle screw and the interbody fusion cage in Model D was the smallest or between Models B and C under different working conditions. Model D had the largest peak stress of APFS and right pedicle screw during anterior flexion. Conclusions APFS combined with contralateral pedicle screw fixation can be used as a novel fixation method for TLIF surgery of lumbar spine.