Abstract:[Objective] To search the relationship between the resection extent of the lumbar facet joint (FJ) and the postoperative clini-cal outcome and the lumbar stability after endoscopic lumbar decompression. [Methods] A retrospective research was conducted on 87 pa-tients who received endoscopic decompression for lumbar spinal stenosis (LSS) in our hospital from January 2019 to October 2023. Basedon the FJ resection extent measured by CT after operation, the patients were divided into four groups, including 22 patients in the minimalgroup with 0~25% FJ resected, 22 patients in the small group with 26%~50% FJ resected, 21 cases in the medium group with 51%~75%FJ resected, and 22 patients in the vast group with 76%~100% FJ resected. The perioperative, follow-up and imaging data of the 4 groupswere compared. [Results] There were no significant differences in operation time, incision length, intraoperative blood loss, intraoperativefluoroscopy times, postoperative walking time, hospital stay and incidence of adverse events among the 4 groups (P＞0.05). All patients inthe 4 groups were followed up for more than 12 months, and the minimal and small groups resumed full weight-bearing activities signifi-cantly earlier than the medium and vast groups [(87.8±4.3) days vs (88.6±8.0) days vs (94.6±7.3) days vs (94.3±8.8) days, P=0.002]. As time went on, the VAS scores for low back pain and leg pain, as well as ODI and JOA scores were significantly improved in all of the 4 groups(P＜0.05). One month after surgery, the minimal and small groups proved significantly superior to the medium and vast groups in terms oflow back pain VAS [(1.9±0.8) vs (2.0±0.5) vs (2.8±0.7) vs (2.9±0.8), P＜0.001], ODI [(27.4±3.5) vs (28.3±1.8) vs (30.1±3.2) vs (30.6±3.2), P=0.002], and JOA score [(25.1±1.3) vs (25.1±1.1) vs (23.1±1.6) vs (23.3±1.6), P＜0.001]. As for imaging, the spinal canal area was significant-ly increased in all the 4 groups after surgery compared with that before surgery (P＜0.05), but the lumbar angular displacement was only sig-nificantly increased in the medium and vast groups (P＜0.05). At the time of the last follow-up, the minimal group and small group was supe-rior to the medium and vast group regarding the lumbar angular displacement [(7.6±2.2)° vs (9.4±3.4)° vs (10.4 ±2.2)° vs (10.6±2.3)°, P＜0.001]. [Conclusion] The greater FJ resection extent under endoscope for LSS, the greater the angular displacement on the image 1 year af-ter surgery. The FJ resection extent is somewhat related to the short-term postoperative symptoms of lumbar pain and the recovery of lum-bar function. Endoscopic decompression should not involve more than 50% of FJ.

Abstract:[Objective] To compare percutaneous transforaminal endoscopic discectomy (PTED) versus quadrant channel discectomy(QCD) in the treatment of lumbar disc herniation. [Methods] A retrospective study was conducted on 78 patients who had single-level discherniation removed surgically in our department in 2022. According to preoperative doctor-patient communication, 40 patients were treatedwith PTED, while other 38 patients were treated with QCD. The perioperative, follow-up and imaging data of the two groups were com-pared. [Results] All patients in both groups had corresponding operations performed successfully without serious complications. Althoughthe PTED was significantly greater than the QCD group in terms of operative time [(65.7±6.4) min vs (34.2±6.7) min, P=0.027] and the expo-sure number of fluoroscopy [(6.8±1.0) times vs (2.4±1.0) times, P=0.004], the former was significantly less than the latter regarding to inci-sion length [(0.8±0.2) cm vs (2.3±0.2) cm, P＜0.001], intraoperative blood loss [(31.6±10.2) ml vs (54.8±11.4) ml, P=0.004] and postopera-tive bed rest time [(2.0±0.6) days vs (3.5±0.5) days, P＜0.001]. As time went by, the VAS scores of low back pain and leg pain, as well asODI score in both groups were significantly decreased (P＜0.05), whereas which were not statistically significant between the two groups atany time points accordingly (P＞0.05). As for imaging, the spinal canal occupying rate significantly reduced (P＜0.05), while the interverte-bral height and lumbar lordotic angle remained unchanged significantly in both groups after operation compared with those preoperatively(P＞0.05). At any corresponding time points, there were no statistically significant differences in imaging indicators between the two groups(P＞0.05). [Conclusion] The clinical consequence of the two techniques on lumbar disc herniation is comparable. By comparison, the PT-ED, despite of taking longer operation time and more intraoperative fluoroscopy times, has considerately less trauma, which facilitates earli-er ambulation and faster recovery over the QCD.

Abstract:[Objective] To compare extreme lateral interbody fusion (XLIF) with unilateral pedicle screw fixation (UPSF) in lateral posi-tion versus bilateral pedicle screw fixation (BPSF) in prone position for the treatment of lumbar degeneration complicated with reducedbone mass. [Methods] A retrospective study was conducted on 57 patients who received XLIF for single-level lumbar degeneration compli-cated with bone mass loss. Based on the preoperative doctor-patients discussion, 25 patients received UPSF, while other 50 patients re-ceived BPSF. The perioperative, follow-up and imaging data of the two groups were compared. [Results] The operation was successfullycompleted in both groups. The UPSF group proved significantly superior to the BPSF group in terms of operation time [(73.6±10.6) min vs(84.8±12.2) min, P＜0.001], incision length [(9.9±1.3) cm vs (14.0±1.4) cm, P＜0.001], intraoperative blood loss [(63.4±17.2) ml vs (86.7±10.8) ml, P＜0.001] and the number of intraoperative fluoroscopy [(6.2±1.2) times vs (13.1±1.6) times, P＜0.001]. The follow-up time was of13~24 months, and there was no significant difference in time to regain full weight bearing activity between the two groups (P＞0.05). TheVAS score of low back pain, VAS score of leg pain and ODI score in both groups were significantly improved over time (P＜0.05), and theUPSF group was significantly better than the BPSF group in VAS score of low back pain [(2.5±0.9) vs (2.9±0.7), P＜0.001] one week aftersurgery. As for imaging, the spinal canal area, vertebral space height, lumbar lordosis angle and fusion rate were significantly improved inboth groups at the last follow-up compared with those preoperatively (P＜0.05), and there were no statistically significant differences in theabove imaging indicators between the two groups at any corresponding time points (P＞0.05). In addition, there was no significant difference in implant loosening between the two groups at the last follow-up (P＞0.05). [Conclusion] XLIF with both BPSF and UPSF under computeraided navigation are safe and effective in the treatment of lumbar degenerative diseases complicated with bone mass loss. Compared withBPSF, the UPSF group had less intraoperative blood loss, less fluoroscopy, shorter operative time and faster postoperative recovery.

Abstract:[Objective] To compare the clinical outcomes of robot-assisted percutaneous vertebroplasty (PVP) versus conventionalmanual PVP in the treatment of osteoporotic vertebral compression fracture (OVCF). [Methods] A retrospective analysis was performed on119 patients who received PVP for single-segment OVCF in our hospital from January 2021 to November 2022. According to the time se-quence of admission, the patients were divided into two groups, 75 patients in the late stage received robot-assisted PVP, while 44 patientsin the early stage received conventional manual PVP through the extrapedicular approach. The data of perioperative period, follow-up andimaging were compared between the two groups. [Results] All patients in both groups had PVP completed successfully. The robot groupproved significantly superior to the manual group in terms of operation time [(19.5±5.3) min vs (28.0±7.4) min, P＜0.001], puncture time[(7.7±4.5) min vs (14.3±6.8) min, P＜0.001], bone cement injection time [(7.3±1.6) min vs (8.7±1.6) min, P＜0.001], intraoperative fluorosco-py times [(24.2±4.1) times vs (28.2±5.5) times, P＜0.001], hospitalization day [(8.2±2.9) days vs (12.3±4.4) days, P＜0.001], one-time suc-cess rate of puncture [cases (%), 67 (89.3) vs 27 (61.4), P＜0.001] and bone cement injection volume [(6.6±1.1) ml vs (5.4±1.4) ml, P＜0.001]. There was no significant difference in the time to resume full weight-bearing activities between the two groups (P＞0.05). With thepassage of time, the VAS and ODI scores in both groups significantly decreased (P＜0.05), whereas which were not statistically significantbetween the two groups at any corresponding time points (P＞0.05). As for imaging, the local Cobb angle and anterior vertebral body marginheight significantly improved in both groups at the last follow-up compared with those preoperatively (P＜0.05), however, there were no sig-nificant differences in the above image indicators between the two groups at any time points accordingly (P＞0.05). [Conclusion] The robotassistedPVP for OVCF is safer, with advantages of shortening operative time, reducing intraoperative fluoroscopy, increasing the amount ofbone cement injection, and effectively strengthening the vertebral body.

Abstract:[Objective] To compare the clinical outcomes of anterior cervical discectomy and fusion (ACDF) with personalized (3Dprinted) zero profile fusion device (the PZPD) versus the finished zero profile fusion device (the FZPD) in the treatment of single-level cer-vical myelopathy. [Methods] A retrospective study was conducted on 46 patients who underwent ACDF for single-level cervical myelopa-thy in our hospital from January 2019 to September 2022. According to doctor-patient communication, 12 patients had ACDF performedwith the PZPD, while other 34 patients were treated with poly-ether-etherke-tone (PEEK) FZPD. The data of the perioperative period, fol-low-up and images were compared between the two groups. [Results] There were no significant differences in operation time, total incisionlength, intraoperative blood loss, fluoroscopy times, ambulation time and hospital stay between the two groups (P＞0.05), but the PZPDgroup consumed significantly less device placement time than the FZPD group [(8.6±0.8) min vs (9.4±0.9) min, P=0.007]. The mean followuptime was (34.1±13.2) months, and there was no significant difference in time to return full weight-bearing activity between the twogroups (P＞0.05). The NDI and JOA scores, as well as pyramidal tract sign were significantly improved in both groups over time postopera-tively (P＜0.05). The PZPD group proved significantly superior to the FZPD group in terms of JOA score [(16.4±0.8) vs (15.9±0.7), P=0.034]6 months postoperativwly, JOA score [(16.7±0.7) vs (16.0±0.8), P=0.008] and NDI score [(0.8±2.0) vs (1.3±1.4), P=0.027] at the latest fol-low-up. Radiographically, the PZPD group had significantly greater intervertebral height than the FZPD group at the last follow-up [(8.4±0.7) mm vs (7.4±0.8) mm, P＜0.001], although there were no statistically significant differences in cervical lordosis angle, spinal canal sagit-tal diameter and Bridwell fusion grade between the two groups at any corresponding time points (P＞0.05). [Conclusion] The personalizedzero profile fusion device has advantages of quick device placement, better intervertebral height maintenance, more effective relief of preop-erative symptoms, and better early clinical efficacy over the finished counterpart in ACDF for cervical myelopathy.

Abstract:[Objective] To compare the clinical consequence of vertebral body augmentation combined with augmented short-segmentpedicle screw fixation (VBA) versus vertebral body bone grafting with short-segment pedicle screw fixation (VBBG) for stage IIIa Kümmelldisease. [Methods] A retrospective study was conducted on patients who had stage IIIA Kümmell disease treated with minimally invasivesurgeries in our hospital from December 2018 to December 2021. According to doctor-patient communication, 18 patients underwent VBA,while other 22 patients underwent VBBG. The perioperative period, follow-up and imaging data of the two groups were compared. [Results]All patients in both groups had corresponding surgical procedures performed successfully, with no serious complications such as nerve inju-ry during the operation. There were no significant differences in operation time, incision length, intraoperative blood loss, intraoperative flu-oroscopy times, postoperative ambulation time and hospital stay between the two groups (P＞0.05). The average follow-up time lasted for(17.7±4.5) months, and there was no significant difference in time to resume full weight-bearing activities between the two groups (P＞0.05).The VAS, ODI and JOA scores in both groups were significantly improved over time (P＜0.05), which were not statistically significant be-tween the two groups at any time point accordingly (P＞0.05). Regarding to imaging, the ratio of anterior vertebra height, local kyphotic an-gle and intervertebral wedge angle in both groups were significantly improved 3 days postoperatively and at the last follow-up comparedwith those preoperatively (P＜0.05). Although there was no statistical significance in the abovesaid imaging measurements between the twogroups before surgery (P＞0.05), the VBA group proved significantly inferior to the VBBG group in terms of ratio of anterior vertebra heightof the injured vertebra [(89.1±7.2)% vs (94.2±11.4)%, P=0.036; (85.5±7.8)% vs (91.3±12.2)%, P=0.019], intervertebral wedge angle [(3.5±3.3)° vs (1.8±2.7)°, P=0.042; (4.9±3.1)° vs (2.7±2.8)°, P=0.018] 3 days postoperatively and at the latest follow-up, however, there was no asignificant difference in local kyphotic angle between the two groups at any matching time point (P＞0.05). [Conclusion] Both vertebral body augmentation combined with augmented short-segment pedicle screw fixation and vertebral body bone grafting with short-segmentpedicle screw fixation achieve satisfactory clinical outcome for stage IIIa Kümmell's disease. In comparison, the latter is superior to the for-mer regarding correction of the anterior height of injured vertebra and the intervertebral wedge angle.

Abstract:Annulus fibrosus suture (AFS) is to promote the closure of annulus fibrous rupture and accelerate its repair, so as to reducethe recurrence rate of intervertebral disc herniation. In this paper, we reported a patient who suffered from recurrent dis herniation after endo-scopic discectomy with AFS. The history, symptoms, clinical manifestations, imaging data, surgical process, intraoperative conditions of revi-sion surgery, and postoperative recovery were reviewed. In addition, the role of AFS in reducing the recurrence rate was also discussed in thispaper to put up an intuitive understanding of significance of AFS. Moreover, this paper also discussed the risk factors of recurrent lumbardisc herniation, and provides reference for the diagnosis and treatment of recurrent lumbar disc herniation after surgery.

Abstract:Lumbar disc herniation is a common disease in orthopaedic clinic, most of which are treated non-surgically. The occurrenceof reabsorption phenomenon provides reliable imaging support for the success of non-surgical treatment. Reabsorption means that herniateddisc tissue may shrink or even disappear to varying degrees. However, the mechanism of reabsorption is not clear. In this paper, the re-search progress of reabsorption mechanism after lumbar disc herniation in recent years is reviewed, in order to provide reference for futureclinical work.

Abstract:Intradural lumbar disc herniation (IDH) is a rare condition, and its diagnosis is often confused with intraspinal tumors. MRIplays a key role in clinical diagnosis and helps in preoperative differential diagnosis. We report two cases, both male, aged 52 and 60 years,involving L4/5 segments. The imaging of case 1 showed rupture of the dura and annulus fibrosa, while case 2 was misdiagnosed as a tumor be-fore surgery and eventually proved to be IDH. The two patients recovered well after surgical treatment without serious complications. Basedon the review of domestic and foreign literature, this paper discusses the treatment strategies of IDH, including the development of micro-scopes and minimally invasive techniques and their application in surgery, aiming to improve the understanding of diagnosis and treatmentof IDH, and provide references for clinicians to diagnose and treat this disease.

Abstract:[Objective] To investigate the relationship between neutrophil to high density lipoprotein cholesterol ratio (NHR) and sarco-penia. [Methods] In this study, eligible subjects aged ≥20 years were selected from the National Health and Nutrition Examination Survey(NHANES) database of 4 cycles survey from 2011 to 2018. Univariate and multivariate logistic regression analyses were used to evaluatethe relation between NHR and sarcopenia, restricted spline analysis (RCS) was used to characterize the dose-response relationship, andthreshold effect analysis was used to calculate the inflection point in the sarcopenia population. Finally, subgroup analysis further verifiedthe robustness of the results. [Results] A total of 10 059 persons were included in the study, including 9 160 without sarcopenia and 899with sarcopenia. The sarcopenia group proved significantly greater than the non-sarcopenia group in terms of neutrophils [(4.9±1.8) vs (4.2±1.7), P＜0.001] and NHR [(4.3±2.1) vs (3.4±1.8), P＜0.001]. Fully adjusted logistic regression models showed that for every 1 unit increasein NHR, the prevalence of sarcopenia increased by 16% (OR=1.16, 95%CI 1.12~1.21). After converting NHR into categorical variables,high levels of NHR were found to be associated with an increase in the prevalence of sarcopenia. Restricted spline analysis showed a posi-tive linear dose-response relationship between NHR and sarcopenia. Threshold effect analysis showed that the inflection point NHR in sar-copenia population was 2.82 and the change of NHR on the left side of the inflection point had a greater impact on sarcopenia. Subgroupanalysis showed that the positive relation between NHR and sarcopenia remained consistent. [Conclusion] NHR is positively associatedwith the risk of sarcopenia, and may be used as a biomarker for early detection and treatment of sarcopenia.

Abstract:[Objective] To introduce the surgical technique and initial clinical results of oblique lateral interbody fusion combined withendoscopic decompression for L₅S₁ herniation complicated with stenosis. [Methods] After general anesthesia, the patient was placed in a lat-eral position on the operating table, and the projection of the intervertebral space on the left side of the body surface was fluoroscopicallyidentified and marked. Computer-assisted navigation scanning and registration were performed in a single position. A skin incision wasmade along the projection of the body surface, and the three layers of abdominal muscles were bluntly separated until the retroperitonealspace was reached. The intervertebral space was confirmed by navigation, and a channel and blade were installed along the guide pin to re-tract and protect the iliac vessels. Intervertebral space was treated through the channel, and then direct decompression of the ventral aspectof the canal was endoscopically performed through the OLIF channel. A suitable interbody cage was implanted in the intervertebral spaceand screw-plate system was placed, finally the incision was closed in layers. [Results] All patients had operation performed smoothly withan average surgical time of (300.2±63.7) min, intraoperative blood loss of (240.4±33.2) ml, ambulation time of (54.4±12.2) hours, and hospi-tal stay of (14±3.2) days. At the latest follow-up lasted for 24 months, the pain visual analogous scale (VAS), ODI score, intervertebralheight, foraminal height, and sagittal diameter of the spine canal were significantly improved compared to those preoperatively. [Conclu-sion] This oblique lateral interbody fusion combined with endoscopic decompression for L5/S1 herniation complicated with stenosis take ad-vantages of direct decompression and the minimally invasive fusion, and achieve satisfactory primary clinical consequence.

Abstract:[Objective] To investigate the clinical efficacy of endoscopic debridement combined with continuous lavage and drainagefor thoracolumbar infection. [Methods] A retrospective study was done on 34 patients who had thoracolumbar infection lesion with or with-out abscess formation treated by abovesaid methods in our center from January 2019 to October 2022. The clinical, laboratory and imagingdocuments were evaluated. [Results] All patients were successfully operated without neurovascular injury and other complications, whilewith the average operative time of (120.3±31.4) min and blood loss of (31.2±13.5) ml. Compared with those preoperatively, the VAS score[(6.2±0.7), (3.1±1.2), P＜0.001] and ODI score [(57.4±6.7), (20.4±5.8), P＜0.001] were significantly reduced at the last follow-up. In addi-tion, the WBC, CRP and ESR significantly decreased over time (P＜0.05). As for imaging, the local kyphotic Cobb angle remained un-changed significantly (P＞0.05), while the intervertebral height [(7.7±1.6) mm, (4.7±3.0) mm, P＜0.001] significantly decreased, and the le-sions state [active/static/healed, (30/4/0), (18/0/16), P＜0.001] improved significantly at the last follow-up compared with those preoperative-ly. [Conclusion] The endoscopic debridement combined with continuous lavage and drainage does achieve satisfactory clinical conse-quence for thoracolumbar infection with or without abscess formation at different locations.

Abstract:[Objective] To evaluate the clinical efficacy of percutaneous interlaminar endoscopic discectomy (PIED) for the treatmentof acute lower limb radical pain due to lumbar disc herniation (LDH) in the elderly. [Methods] From June 2020 to June 2023, 43 elderly pa-tients with acute lower limb radical pain due to LDH were treated with PIED at our institution. The clinical and imaging data were collectedand analyzed. [Results] All patients had operation performed smoothly with incision length of (0.8±0.1) cm, intraoperative blood loss of(70.3±26.4) ml, operation time of (89.3±7.6) minutes, and hospital stay of (6.9±2.6) days, while without complications, such as dural tear,nerve root injury and cerebrospinal fluid leakage. With time preoperatively, 3 months postoperatively and the latest follow-up lasted formore than one year, there were significant improvements in terms of the back pain VAS score [(6.7±1.6), (2.5±0.8), (1.6±0.8), P＜0001], legpain VAS score [(6.5±1.8), (2.3±1.2), (1.6±0.9), P＜0.001], ODI index [(34.2±5.6), (13.8±4.2), (9.4±2.5), P＜0.001], JOA score [(10.5±2.3),(23.2±3.2), (25.1±3.0), P＜0.001], sagittal foramen diameter measured on images [(1.6±1.1) mm, (2.8±1.4) mm, (2.6±1.4) mm,P ＜0.001],and intervertebral height [(6.1±1.6) mm, (10.4±1.2) mm, (9.6±0.9) mm, P＜0.001]. However, no significant changes were noted in the lum-bar lordotic angle (P＞0.05). [Conclusion] PIED provides effective relief from acute lower limb radical pain due to LDH in elderly, repre-sents a safe, effective therapeutic option for this condition.

Abstract:[Objective] To evaluate the efficacy of unilateral biportal endoscopic lumbar interbody fusion (UBE-LIF) in the treatmentof degenerative lumbar diseases. [Methods] A retrospective analysis was conducted on 413 patients who had single-segment degenerativelumbar diseases treated by UBE-LIF treatment at our hospital from 2019 to 2022. The clinical and imaging documents were evaluated. [Re-sults] All the patients had UBE-LIF performed successfully with the average operative time of (158.3±17.2) min, the average intraopera-tive blood loss of (217.5±22.1) ml, and were followed up for a mean of (17.3±3.1) months. With time preoperatively, 6 months after surgeryand at the last follow-up, the low back pain VAS [(6.9±0.6), (1.6±0.3), (1.4±0.2), P＜0.001], leg pain VAS [(8.0±0.7), (1.5±0.5), (1.3±0.4),P＜0.001] and ODI scores [(78.5±6.1), (17.5±3.7), (17.5±3.7), P＜0.001] were significantly declined. In term of imaging, the spinal canal ar-ea [(128.6±19.8) mm², (238.2±12.5) mm², (223.4±12.7) mm², P＜0.001], lateral recess sagittal diameter [(1.5±0.5) mm, (6.3±0.5) mm, (6.0±0.5) mm, P＜0.001] and intervertebral height [(7.5±0.7) mm, (12.3±0.5) mm, (11.8±0.5) mm, P＜0.001] were significantly improved over thetime period abovementioned. The CT showed that the fusion rate was 92.5% 6 months after operation, while the MacNab excellent and goodrate of the clinical consequence was of 94.4% at the last follow-up and the postoperative complication rate was of 4.6%. [Conclusion] Al-though the UBE-LIF consumed longer operation time, it achieves good overall clinical outcome, with low postoperative complication.

Abstract:[Objective] To investigate the clinical consequence of debridement and instrumented fusion through a mere posterior ap-proach for upper-middle-segment thoracic spine (T4~6) tuberculosis. [Methods] A retrospective study was conducted on 67 patients whohad T4~6 tuberculosis treated surgically by abovesaid technique in our hospital from January 2011 to January 2016. The clinical and auxilia-ry examination data were evaluated. [Results] All patients had the surgical procedures performed successfully with the average operationtime of (165.1±27.9) min, and average intraoperative blood loss of (792.5±297.2) ml. All of them were followed up for more than 5 years. Astime elapsed from the point before operation, 1 month postoperatively to the latest follow-up, the VAS score [(7.1±1.1), (1.7±0.2), (1.3±1.1),P＜0.001], ODI [(48.9±15.4), (20.2±1.7), (11.2±4.1), P＜0.001] significantly reduced. However, compared with that preoperatively, the ASIAneurological function grade significantly improved at the last follow-up [B/C/D/E, (3/5/19/40), (0/2/3/62), P＜0.001]. As for auxiliary exami-nation, the local kyphotic angle [(34.8±10.9)°, (10.2±1.3)°, (11.3±3.2)°, P＜0.001], ESR [(50.9±16.6) mm/h, (16.9±3.2) mm/h, (10.1±2.4)mm/h, P＜0.001] and CRP [(34.1±16.7) mg/L, (9.2±2.5) mg/L, (2.6±2.0) mg/L, P＜0.001] were significantly decreased over time. [Conclu-sion] The debridement and instrumented fusion through a mere posterior approach do effectively remove the lesions and correct the kyphot-ic deformity, and achieve a satisfactory outcomes for T4~6 tuberculosis.

Abstract:[Objective] To compare the morphological differences in lumbar pedicle between isthmic spondylolisthesis and simple lum-bar spinal stenosis, and analyze its clinical significance. [Methods] From January 2020 to October 2023, 62 patients with L5 isthmic spon-dylolisthesis (the IS group) and 45 patients with simple L5S1 spinal stenosis (the SS group) who underwent posterior pedicle screw internalfixation in our hospital were included in this study. There were 31 cases of grade I and 31 cases of grade II. The CT parameters were com-pared between the IS group and the SS group as well as the spondylolisthesis subgroups. [Results] From L1 to L5, the IS group proved signifi-cantly greater than the SS group in terms of pedicle angle (PA) [(12.4±2.8)° vs (8.9±2.7)°, P＜0.001; (13.4±2.7)° vs (10.2±2.7)°, P＜0.001;(18.2±3.9)° vs (14.6±3.4)°, P＜0.001; (22.3±4.8)° vs (17.2±4.5)°, P＜0.001; (31.5±4.7)° vs (28.3±4.7)°, P=0.002], and pedicle length (PL)[(18.3±1.6) mm vs (17.4±1.6) mm, P=0.008; (17.1±1.3) mm vs (16.3±1.7) mm, P=0.020; (16.9±1.7) mm vs (16.1±1.7) mm, P=0.029; (14.7±1.4) mm vs (14.1±1.4) mm, P=0.018; (15.8±1.5) mm vs (14.3±2.1) mm, P＜0.001]. In addition, the IS group had significantly greater screwtrajectory length (STL) than the SS group (P＜0.05), whereas the former had significantly less pedicle width (PW) than the latter from L1 toL5 levels (P＜0.05). However, there was no significant difference in all CT parameters from L1 to L5 levels between degree I and degree II ISsubgroups (P＞0.05). [Conclusion] The isthmic spondylolisthesis presents the lumbar pedicle change of thinning and lengthening, whichmay be related to the pathogenesis. The inward angle of pedicle screw placement should appropriately be increased.

Abstract: