Lumbar spinal stenosis(LSS) is a common degenerative spinal disease. Over the past 30 years, under the concept of minimally invasive spine surgery (MISS), spinal endoscopy has seen significant advancements, particularly in endoscopic unilateral laminotomy for bilateral decompression (ULBD). This technique, utilizing a fluid medium and small incision, achieves spinal canal decompression while maintaining spinal stability, resulting in satisfactory clinical outcomes. However, endoscopic spinal decompression surgery still has some complications, such as nerve injury, dural tears, myeloid hypertension, and epidural hematomas. Some scholars have begun exploring robotic endoscopic spinal surgery to reduce complications and improve clinical outcomes. This article provides an overview of the current state of endoscopic treatment for LSS, aiming to equip surgeons with a comprehensive understanding of this surgical approach to deliver better patient care.

Objective:To explore the correlation between mechanical complications and paraspinal muscle degeneration following posterior single-segment osteotomy corrective surgery for chronic osteoporotic vertebral compression fractures (OVCF).Methods:A retrospective analysis was conducted on 80 patients who underwent surgery between January 2008 and January 2021 at Peking University Third Hospital. These patients, who developed kyphotic deformity following OVCF, included 17 males and 63 females with a mean age of 63.21±8.07 years (range, 47-77 years). Postoperative mechanical complications included proximal junctional kyphosis (PJK), screw loosening, adjacent segment degeneration (ASD), and distal junctional kyphosis or failure. Patients were compared based on the occurrence of mechanical complications in relation to fat infiltration (FI), relative gross cross-sectional area (rGCSA), and relative functional cross-sectional area (rFCSA) of the paraspinal muscles. Binary logistic regression analysis was used to identify risk factors for postoperative complications.Results:Among the 80 patients, 19 developed PJK, while 61 did not. The PJK group exhibited significantly higher paraspinal muscle FI (0.44±0.05) compared to the non-PJK group (0.38±0.10, P<0.05). Screw loosening occurred in 7 cases, with 73 cases remaining stable. Those with screw loosening demonstrated higher paraspinal muscle FI (0.47±0.05) than those without (0.38±0.09, P<0.05). Thirty patients experienced ASD, while 50 did not. The ASD group had higher paraspinal muscle FI (0.45±0.07) and lower rFCSA (0.09±0.03) compared to the non-ASD group (0.36±0.10 and 0.13±0.06, respectively, P<0.05). Logistic regression analysis indicated that paraspinal muscle FI and rFCSA were not independent risk factors for developing ASD. Twenty-three patients experienced distal junctional kyphosis or failure, while 57 did not; those with complications exhibited higher paraspinal muscle FI (0.48±0.08) and lower rGCSA (0.16±0.04) and rFCSA (0.09±0.03) compared to those without complications (0.37±0.09, 0.20±0.09, and 0.13±0.06, respectively, P<0.05). Logistic regression analysis suggested that paraspinal muscle FI, rGCSA, and rFCSA were not independent risk factors for developing distal junctional kyphosis or failure. Conclusion:Mechanical complications following corrective surgery for chronic OVCF-related kyphosis may be associated with increased paraspinal muscle FI. Additionally, the occurrence of ASD and distal junctional kyphosis or failure may correlate with reduced paraspinal muscle rFCSA

Objective:To investigate the clinical efficacy of percutaneous kyphoplasty (PKP) assisted by intuitive visual navigation orthopaedic surgery robot in the treatment of osteoporotic vertebral compression fracture (OVCF).Methods:A retrospective analysis was conducted in Peking University Third Hospital from June 2021 to November 2022, 78 patients with OVCF were treated by the intuitive visual navigation orthopaedic surgery robot or freehand surgery with a "C" arm X-ray machine. According to the method of puncture, they were divided into robot group and freehand group. In the robot group, there were 36 cases, including 7 males and 29 females, aged 74.50±5.87 years, 32 cases of single vertebral fractures, 4 cases of double vertebral fractures, 1 case of T 8, 2 cases of T 10, 2 cases of T 11, 11 cases of T 12, 10 cases of L 1, 8 cases of L 2, 2 cases of L 3, 3 cases of L 4, and 1 case of L 5. Bone mineral density T value was -2.94±0.50; In the freehand group, there were 42 cases, including 9 males and 33 females, aged 72.86±8.84 years, 36 cases of single fracture and 6 cases of double fracture, 1 case of T 6, 2 cases of T 7, 3 cases of T 11, 9 cases of T 12, 8 cases of L 1, 9 cases of L 2, 5 cases of L 3, 6 cases of L 4, and 5 cases of L 5. Bone mineral density T value was -3.00±0.50. The effectiveness evaluation indexes of the two groups were compared, which included surgery duration, X-ray fluoroscopy times, hospitalization time, lumbar pain visual analogue scale (VAS), Oswestry disability index (ODI) and height of fractured anterior vertebrae (HFAV). Results:Both groups of patients successfully received surgical treatment. The mean operating time of the robot group was 33.44±2.50 min, which was significantly longer than that of the free hand group, which was 29.69±2.40 min ( t=6.491, P<0.001). Meanwhile, the intraoperative blood loss of the robot group was 3.54±0.89 ml, which was significantly less than that of the freehand group, which was 6.72±1.89 ml ( t=9.110, P<0.001). In terms of radiographic fluoroscopy times, the average of the robot group was 26.81±7.76 times, which was significantly less than the freehand group's 42.61±6.62 times ( t=9.294, P<0.001). The postoperative vertebral front edge height in the free hand group was 18.64±0.32 mm and in the robot group was 18.79±0.36 mm. The difference was not statistically significant ( t=2.673, P=0.067). All patients were followed up for 8.3±2.9 months (range, 6-13 months). The VAS scores of low back pain in the two groups at 1 day and 6 months after operation were significantly improved compared with those before operation ( P<0.05), and there was no significant difference between the two groups in VAS score after operation ( P>0.05). Six months after surgery, the ODI of the free hand group and the robot group were 11.67%±2.13% and 12.11%±2.33%, respectively. The ODI scores of the two groups were significantly lower at 6 months postoperative follow-up than that before surgery, and the postoperative follow-up at all had significant differences compared with that before surgery ( P<0.05), and there was no difference between the two groups in postoperative ODI scores ( P>0.05). No obvious bone cement leakage was found in all patients during operation. Conclusion:Compared with the traditional C-arm X-ray for PKP treatment of OVCF by free hand, intuitive visual navigation orthopedic robot can safely and effectively assist in the completion of the operation process, and has the advantages of less intraoperative blood loss, fewer fluoroscopy times.

Objectives:To investigate the incidence and risk factors of perioperative complications after en bloc resection for thoracic and lumbar spinal tumors.Methods:The data of patients with thoracic and lumbar spinal tumors treated in our department with en bloc resection and anterior column reconstruction were retro-spectively analyzed.Between May 2016 and October 2022,90 consecutive patients underwent en bloc resec-tion on the basis of Weinstein-Boriani-Biagini surgical staging system,and anterior reconstruction was per-formed using 3D-printed artificial vertebral bodies.The demographic,oncological,and operative data of the patients were collected prospectively,and the intraoperative and postoperative complications occurring within three months were categorized into major and minor complications according to their impacts on the recovery process(Major complications were considered as any complication that appeared to substantially alter an other-wise full and expected course of recovery,and other complications were regarded as minor).All the patients were divided into the primary group(n=67)and revision group(n=23)based on their previous surgical history.Differences between the two groups in terms of age,gender,pathological type,tumor-involved segments,oper-ative time,intraoperative blood loss,and perioperative complications were compared.The predictive factors for major and minor complications were explored.Results:En bloc resection was achieved in all the patients,in-cluding total en bloc spondylectomy in 77 cases,sagittal resection in 12 cases,and vertebrectomy in one case.The mean operative time was 553.4min(210-1208min),and the mean intraoperative blood loss was 1534.1mL(260-5500mL).A total of 129 complications were observed in 65(72.2%)patients,including 29 ma-jor complications in 21(23.3%)patients.Two patients(2.2%)died as a result of complications.The revision group was more than primary group in tumor-involved segments(P=0.000)and incidence rate of major compli-cations(P=0.038).In univariate regression analysis,the combined approach[odds ratio(OR)=14.778,P=0.001],total blood loss(OR=1.004,P=0.004),staged surgery(OR=5.250,P=0.008),previous surgical history(OR=2.946,P=0.043),number of tumor-involved vertebrae(OR=1.607,P=0.023)and lumbar tumor(OR=3.509,P=0.015)were statistically significant risk factors for major complication occurrence,while the combined approach(OR= 6.375,P=0.036)was the independent risk factor.Conclusions:En bloc resection and anterior column recon-struction is associated with high risks of complications,especially when a combined approach is needed.

Objective Cervical disc herniation(CDH)is one of the common orthopaedic diseases.With the in-depth study of it and the development of cervical implants,the establishment of cervical fusion animal models has become an indispensable part.Notably however,studies of the establishment and evaluation of cervical fusion animal models in China are currently lacking.This study aimed to provide a suitable animal model and evaluation scheme for implants for cervical spine-related research.Methods Small-tailed Han sheep were chosen for anterior cervical discectomy fusion(ACDF)after modified surgery,and a polyetheretherketone(PEEK)interbody fusion cage(Cage)(control group),3D-printed Ti6Al4V Cage(group 1),and new method Ti6Al4V Cage(group 2)were implanted in different cervical segments(C2/3～C4/5)in each sheep,respectively.Hematology and histopathological analyses were carried out after surgery to evaluate recovery of sheep and the biosafety of the materials.Bone in-growth and bone fusion were assessed by X-ray,computed tomography(CT),Micro-CT and quantitative analysis,hard tissue section staining,and biomechanical tests.Results The modified ACDF ovine model was established successfully.There were no significant differences in important hematology indexes(P＞0.05)and histopathological analysis showed no pathological changes,such as inflammatory cell infiltration.The implants had good biosafety.Furthermore,X-ray and CT examinations showed that the position of internal fixation and the interbody fusion were good.Micro-CT and quantitative analysis at 3 and 6 months after operation showed that compared with PEEK Cage group,the bone volume/total volume and trabecular number were significantly increased(P＜0.01)while the trabecular spacing was significantly decreased in the new method Ti6Al4V and 3D-printed Ti6Al4V groups compared with the PEEK Cage group(P＜0.01).Moreover,the new method new method Ti6Al4V Cage group had more bone growth(P＜0.01).Hard tissue section staining demonstrated that the pores of the new method Ti6Al4V Cage and 3D-printed Ti6Al4V Cage had obvious bone growth and relatively dense pores in the new method Ti6Al4V and 3D-printed Ti6Al4V groups,and the combination was slightly better than that of PEEK Cage.Biomechanical evaluation indicated that the new method Ti6Al4V Cage and 3D-printed Ti6Al4V Cage reduced the range of cervical flexion-extension,lateral bending,and axial rotation(P＜0.05)compared with the PEEK cage,as well as enhancing the stability of the cervical vertebra,and the new method Ti6Al4 V Cage was more advantageous(P＜0.05).Conclusions After the establishment of the modified ACDF ovine model,reasonable and effective assessment method were used to demonstrate the suitability and effectiveness of the model and the good biosecurity of all three Cage materials.Compared with the PEEK Cage,the new method Ti6Al4V Cage and 3D-printed Ti6Al4V Cages showed better performances in terms of bone growth and bone fusion,which could enhance the stability of the cervical vertebrae.The new method Ti6Al4V Cage was particularly advantageous.

Objective To explore the efficacy of Krackow locking loop technique combined with the modified Kessler suture technique in the treatment of acute closed Achilles tendon rupture.Methods From January 2020 to January 2022,162 cases of acute closed Achilles tendon rupture were treated with Krackow locking loop technique combined with the modified Kessler suture technique.The patients were treated with the same postoperative rehabilitation plans.The American Orthopaedic Foot and Ankle Society(AOFAS)hindfoot score and Achilles Tendon Total Rupture Score(ATRS)were collected to evaluate the functions.Results The operation time was 24-40 min(mean,31.9±4.6 min).All incisions healed in one stage without infection or sural nerve injury.Complications occurred in 2 patients,including 1 case of deep venous thrombosis and 1 case of trauma-related re-rupture.The recovery time of ankle flexion and extension motion was4-12 weeks(mean,7.6±1.9 weeks),the recovery time of single-legged heel rise height on the affected side was 10-18 weeks(mean,13.3±1.8 weeks),and the recovery time of fast walking or jogging was 14-26 weeks(mean,19.1±1.8 weeks).The 162 patients was followed up for 14-25 months(mean,19.0 months).The AOFAS hindfoot score increased from(54.4±4.4)points preoperatively to(98.0±4.0)points at the last follow-up(t =-104.402,P =0.000).The ATRS score increased from(52.0±8.3)points preoperatively to(91.2±2.4)points at the last follow-up(t =-62.823,P = 0.000).Conclusions For young and middle-aged patients with acute closed Achilles tendon rupture,Krackow locking loop technique combined with the modified Kessler suture technique can achieve good clinical outcomes.Early functional exercise is required to return to work and life.

Objective To observe the effect of different synovial cell secretions on chondrocytes after LPS-induced inflammation,and to explore the mechanism of two synovial cell secretions causing cartilage damage in the progres-sion of KOA disease.Methods Two kinds of synovial cells were co-cultured at 1∶4 and LPS-induced inflamma-tion.The supernatant and exocrine were extracted,and then the normal and LPS-induced inflammation were extrac-ted.The human cartilage tissue obtained during the operation was isolated and cultured into chondrocytes,which were divided into five groups:the first group was added with FLS secretion,the second group was added with nor-mal FLS secretion,the third group was added with secretion after co-culture of two kinds of synovial cells,the fourth group was added with inflammatory MLS secretion,and the fifth group was added with inflammatory FLS se-cretion.CCK-8 was used to detect the viability of chondrocytes in each group.TNF-α,IL-1β,IL-6 level in the su-pernatant of chondrocytes in each group was detected by ELISA.The protein expression of TLR4,NF-κB,IkK,IκB,ADAMTS5 in chondrocytes of each group was detected by Western blot method.Results CCK-8 showed that the activity of chondrocytes in the three groups of inflammatory secretions decreased compared with the secretions from normal synovial cells(P＜0.05);ELISA showed TNF-α,IL-1 β,IL-6 level in the supernatant of group Ⅲ,Ⅳ and V was higher than that of group Ⅰ and Ⅱ(P＜0.05),TNF-α,IL-1 β,IL-6 level in group Ⅲ was higher than that in group Ⅳ but lower than that in group Ⅴ(P＜0.05).Western blot showed the protein expression of TLR4,NF-κB,IkK,IκB,ADAMTS5 in chondrocytes of group Ⅲ,Ⅳ and Ⅴ was higher than that in group Ⅰ and Ⅱ(P＜0.05),the protein expression of TLR4,NF-κB,IkK,IκB,ADAMTS5 in group Ⅲ was higher than that in group Ⅳbut lower than that in group Ⅴ(P＜0.05).Conclusion Two kinds of synovial cell-derived secretions after LPS-induced inflammation can regulate cartilage TLRs/NF-κB signal pathway,causing cartilage inflammation.The in-flammatory effect of MLS secretion is stronger than that of FLS secretion,but the inflammatory effect of MLS secre-tion under two co-cultures is weaker than that of MLS secretion alone.

Objective:To explore the short-term outcomes of 3D-printing stand-alone artificial vertebral body(AVB)in the surgical procedure of anterior cervical corpectomy and fusion(ACCF).Methods:Following the proposal of IDEAL(idea,development,exploration,assessment,and long-term follow-up)framework,we designed and conducted this single-armed,retrospective cohort study.The patients with cervical spondylotic myelopathy were recruited,and these patients exclusively received the surgical procedure of single-level ACCF in our single center.After the process of corpectomy,the size was tailored using different trials and the most suitable stand-alone AVB was then implanted.This AVB was manufactured by the fashion of 3D-printing.Two pairs of screws were inserted in an inclined way into the adjacent vertebral bodies,to stabilize the AVB.The participants were regularly followed-up after the operation.Their clinical data were thoroughly reviewed.We assessed the neurological status according to Japanese Orthopedic Association(JOA)scale.We determined the fusion based on imaging examination six months after the operation.The recorded clinical data were analyzed using specific software and they presented in suitable styles.Paired t test was employed in comparison analysis.Results:In total,there were eleven patients being recruited eventually.The patients were all followed up over six months after the operation.The mean age of the cohort was(57.2±10.2)years.The mean operation time was(76.1±23.1)min and the median bleeding volume was 150(100,200)mL.The postoperative course was uneventful for all the cases.Dysphagia,emergent hematoma,and deterioration of neurological func-tion did not occur.Mean JOA scores were 13.2±2.2 before the operation and 16.3±0.8 at the final follow-up,which were significantly different(P＜0.001).The mean recovery rate of neurological func-tion was 85.9％.By comparing the imaging examinations postoperatively and six months after the opera-tion,we found that the average subsidence length was(1.2±1.1)mm,and that there was only one ca-ses(9.1％)of the severe subsidence(＞3 mm).We observed significant improvement of cervical lor-dosis after the operation(P=0.013).All the cases obtained solid fusion.Conclusion:3D-printing stand-alone AVB presented favorable short-term outcome in one-level ACCF in this study.The fusion rate of this zero-profile prosthesis was satisfactory and the complication rate was relatively low.

The training of orthopedic residents in Taiwan, China includes post graduate year and specialist training, which contain continuous orthopedic specialist training, humanistic training, and holistic education to ensure the high post competency of orthopedic residents. The training process is oriented towards competency and outcome, emphasizing the cultivation of core competencies. Comprehensive quantitative standards have been established to comprehensively evaluate the post competency of residents through theoretical, technical, and clinical work assessments. In this paper, the literature on medical education and resident training in Taiwan was reviewed. The overall training system, assessment requirements, and humanistic training of orthopedic residents in Taiwan were introduced. In addition, the models of training orthopedic specialists were compared between Taiwan and Mainland of China represented by Peking University Medical Department to provide reference for the training program of orthopedic residents.

Objective:To investigate the application effect of the comprehensive innovative teaching model with "3D printed model combined with visual surgical simulation" as the core in the clinical teaching of extremity bone defects.Methods:The physicians who participated in the clinical management of patients with extremity bone defects in Department of Orthopedics, Peking University Third Hospital, from March 2019 to December 2021 were selected as subjects and were divided into standardized training group with 52 physicians and refresher physician group with 58 physicians. Teaching and training was performed for the special disease of extremity bone defects, including basic knowledge teaching, dressing change for infected wounds, multidisciplinary discussion, digital surgical simulation, and practical surgical operation. The assessment indices for teaching quality included the assessment of theoretical knowledge and clinical skills, the objective evaluation of the clinical ability of patient management, and an investigation of the degree of satisfaction. SPSS 22.0 was used for the t-test and the chi-square test. Results:After training, both groups had significant increases in the assessment scores of theoretical knowledge [(32.4±6.7）and (42.2±3.8)] and clinical practice skills [(19.6±2.0), (20.8±2.2), (20.5±2.5), (21.5±2.3)]( P<0.05). After training, the standardized training group had significant increases in the scores of six objective evaluation indicators [(8.3±0.8) vs. (6.9±1.1), (7.4±0.7) vs. (6.3±1.5), (7.2±1.3) vs. (5.0±1.4), (7.9±1.2) vs. (4.0±1.5), (8.4±0.8) vs. (6.4±1.6), (40.3±2.6) vs. (28.6±2.4)]( P<0.01), while the refresher physician group had significant improvements in four aspects, i.e., the understanding of extremity bone defects [(8.1±0.9) vs. (7.2±1.1)], the self-confidence in facing complex extremity bone defects [(8.1±1.2) vs. (6.6±0.9)], spatial thinking ability in repair surgery for bone defects [(8.6±0.8) vs. (7.3±0.9)], and overall clinical performance in actual management of patients with bone defects [(41.4±2.3) vs. (37.3±1.8)] ( P<0.01). The satisfaction score for this comprehensive innovative teaching model was (95.3±3.2) points in the standardized training group and (94.8±2.8) points in the refresher physician group. Conclusions:The comprehensive innovative teaching model with "3D printed model combined with visual surgical simulation" as the core can significantly improve the basic knowledge and clinical skills of physicians in a short period of time and meet the needs for learning surgical techniques and advanced diagnosis and treatment concepts among refresher physicians.