Extracellular vesicles (EVs), defined as cell-secreted nanoscale vesicles that carry bioactive molecules, have emerged as a promising therapeutic strategy in tumor and tissue regeneration. Their potential in repairing intervertebral disc degeneration (IDD) through multidimensional regulatory mechanisms is a rapidly advancing field of research. This paper provided an overview of the mechanisms of EVs in IDD repair, thoroughly reviewed recent literature on EVs for IDD, domestically and internationally, and summarized their therapeutic mechanisms. In IDD repair, EVs could act through different mechanisms at the molecular, cellular, and tissue levels. At the molecular level, EVs could treat IDD by inhibiting inflammatory reactions, suppressing oxidative stress, and regulating the synthesis and decomposition of extracellular matrix. At the cellular level, EVs could treat IDD by inhibiting cellular pyroptosis, ferroptosis, and apoptosis and promoting cell proliferation and differentiation. At the tissue level, EVs could treat IDD by inhibiting neovascularization. EVs have a strong potential for clinical application in the treatment of IDD and deserve more profound study.
Extracellular Vesicles/physiology* ; Humans ; Intervertebral Disc Degeneration/therapy* ; Apoptosis ; Cell Proliferation ; Oxidative Stress ; Cell Differentiation ; Extracellular Matrix/metabolism* ; Animals ; Pyroptosis

The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Humans ; Finite Element Analysis ; Intervertebral Disc/physiology* ; Lumbar Vertebrae/physiology* ; Weight-Bearing/physiology* ; Biomechanical Phenomena ; Stress, Mechanical ; Computer Simulation ; Models, Biological

OBJECTIVE: To measure and analyze the relationships among the posterior tibial slope (PTS), meniscal slope (MS), and meniscus posterior horn thickness (MPHT) of the medial and lateral tibial plateau in healthy people and patients with anteromedial osteoarthritis (AMOA) in Heilongjiang province, so as to provide reference basis for appropriate tibial osteotomy and prosthesis placement angles in knee joint surgeries. METHODS: A retrospective collection of imaging data from knee joint MRI examinations conducted prior to AMOA for various reasons was performed. A total of 103 healthy individuals (healthy group) and 30 AMOA patients (AMOA group) were included. There was no significant difference in the gender composition ratio, side, and body mass index between the two groups ( P>0.05); however, the comparison of ages between the two groups showed a significant difference ( P<0.05). The collected DICOM format image data was imported into the RadiAnt DICOM Viewer software and measured the medial PTS (MPTS), lateral PTS (LPTS), medial MS (MMS), lateral MS (LMS), medial MPHT (MMPHT), and lateral MPHT (LMPHT) with standard methods. The differences of the above indexes between the two groups and between different genders and sides in the two groups were compared, and Pearson correlation analysis was carried out. At the same time, the measured data of healthy group were compared with the relevant literature reported in the past. RESULTS: Compared to the healthy group, the AMOA group exhibited significantly smaller MPTS and LPTS, as well as significantly greater MMPHT and LMPHT, with significant differences ( P<0.05). However, there was no significant difference in the MMS and LMS between the two groups ( P>0.05). The differences in various indicators between genders and sides within the two groups were not significant ( P>0.05). The correlation analysis and regression curves indicated that both MPTS and LPTS in the two groups were positively correlated with their respective ipsilateral MS and MPHT ( P<0.05); as PTS increased, the rate of increase in MS and MPHT tend to plateau. Compared to previous related studies, the MPTS and LPTS measured in healthy group were comparable to those of the Turkish population, exhibiting smaller values than those reported in other studies, while MMS and LMS were relatively larger, and MMPHT and LMPHT were smaller. CONCLUSION In healthy people and AMOA patients in Heilongjiang province, PTS has great individual differences, but there is no significant individual difference in MS. MPHT can play a certain role in retroversion compensation, and its thickness increase may be used as one of the indicators to predict the progression of AMOA. The above factors should be taken into account when UKA is performed, and the posterior tilt angle of tibial osteotomy should be set reasonably after preoperative examination and evaluation.
Humans ; Osteoarthritis, Knee/surgery* ; Retrospective Studies ; Tibia/pathology* ; Male ; Female ; Adult ; Menisci, Tibial/anatomy & histology* ; China ; Knee Joint/pathology* ; Magnetic Resonance Imaging ; Middle Aged ; Aged ; Osteotomy

OBJECTIVE: To investigate the effectivess of arthroscopic Wafer surgery combined with triangular fibrocartilage complex (TFCC) insertion point reconstruction in the treatment of Palmer type ⅡC combined with typeⅠB ulnar impingement syndrome. METHODS: The clinical data of 14 patients with Parlmer type ⅡC combined with type ⅠB ulnar impingement syndrome who met the selection criteria between July 2021 and April 2024 were retrospectively analyzed. There were 7 males and 7 females with an average age of 43 years ranging from 16 to 59 years. The causes of injury were fall in 8 cases and sprain in 6 cases. The time from injury to operation ranged from 1 to 6 months, with an average of 2.3 months. Distal radioulnar joint instability was found in all cases. Arthroscopic Wafer surgery combined with TFCC insertion point reconstruction was used. The effectiveness was evaluated by comparing the wrist flexion-dorsiflexion range of motion, wrist ulnar deviation-radial deflection range of motion, forearm pronation-supination range of motion, visual analogue scale (VAS) score, and modified Mayo wrist score before and after operation. RESULTS: All patients were followed up 6-12 months, with an average of 9.1 months. The positive variation of ulna was (3.2±0.7) mm before operation, and the negative variation of ulna was (2.2±0.6) mm after operation. There was a significant difference in ulna variation between pre- and post-operation ( t=23.851, P<0.001). The pain symptoms and forearm rotation function of the patients after operation significantly improved. At last follow-up, the wrist flexion-dorsiflexion range of motion, wrist ulnar deviation-radial deflection range of motion, forearm pronation-supination range of motion, VAS score, and modified Mayo wrist score significantly improved when compared with those before operation ( P<0.05). CONCLUSION Arthroscopic Wafer surgery combined with TFCC insertion point reconstruction can effectively relieve wrist pain, enhance the stability of the distal radioulnar joint, and restore the function of the wrist in patients with Palmer type ⅡC combined with type ⅠB ulnar impingement syndrome.
Humans ; Male ; Adult ; Arthroscopy/methods* ; Female ; Triangular Fibrocartilage/surgery* ; Middle Aged ; Range of Motion, Articular ; Retrospective Studies ; Wrist Joint/physiopathology* ; Adolescent ; Young Adult ; Ulna/surgery* ; Treatment Outcome ; Wrist Injuries/surgery* ; Plastic Surgery Procedures/methods* ; Joint Instability/surgery*

OBJECTIVE: To investigate the short-term effectiveness of uni-portal non-coaxial spinal endoscopic surgery (UNSES) via crossing midline approach (CMA) in the treatment of free lumbar disc herniation (FLDH). METHODS: Between March 2024 and June 2024, 16 patients with FLDH were admitted and treated with UNSES via CMA. There were 9 males and 7 females with an average age of 55.1 years (range, 47-62 years). The disease duration was 8-30 months (mean, 15.6 months). The pathological segments was L _{3, 4} in 4 cases, L _{4, 5} in 5 cases, and L ₅, S ₁ in 7 cases. The preoperative pain visual analogue scale (VAS) score was 6.9±0.9 and the Oswestry disability index (ODI) was 57.22%±4.16%. The operation time, intraoperative bleeding volume, postoperative hospital stay, and incidence of complications were recorded. The spinal pain and functional status were evaluated by VAS score and ODI, and effectiveness was evaluated according to the modified MacNab criteria. CT and MRI were used to evaluate the effect of nerve decompression. RESULTS: All 16 patients underwent operation successfully without any complications. The operation time was 63-81 minutes (mean, 71.0 minutes). The intraoperative bleeding volume was 47.3-59.0 mL (mean, 55.0 mL). The length of hospital stay after operation was 3-4 days (mean, 3.5 days). All patients were followed up 1-3 months, with 15 cases followed up for 2 months and 14 cases for 3 months. The VAS score and ODI gradually decreased over time after operation, and there were significant differences between different time points ( P<0.05). At 3 months after operation, the effectiveness was rated as excellent in 12 cases and good in 2 cases according to the modified MacNab criteria, with an excellent and good rate of 100%. CT and MRI during follow-up showed a significant increase in the diameter and cross-sectional area of the spinal canal, indicating effective decompression of the canal. CONCLUSION When using UNSES to treat FLDH, choosing CMA for nerve decompression has the advantages of wide decompression range, large operating space, and freedom of operation. It can maximize the preservation of the articular process, avoid fracture and breakage of the isthmus, clearly display the exiting and traversing nerve root, and achieve good short-term effectiveness.
Humans ; Male ; Intervertebral Disc Displacement/diagnostic imaging* ; Middle Aged ; Female ; Lumbar Vertebrae/surgery* ; Endoscopy/methods* ; Treatment Outcome ; Operative Time ; Pain Measurement ; Length of Stay

OBJECTIVE: To review clinical application and research progress of different types of intelligent responsive hydrogels in repairing articular cartilage injury. METHODS: The animal experiments and clinical studies of different types of intelligent responsive hydrogels for repairing articular cartilage injury were summarized by reviewing relevant literature at home and abroad. RESULTS: The intrinsic regenerative capacity of articular cartilage following injury is limited. Intelligent responsive hydrogels, including those that are temperature-sensitive, light-sensitive, enzyme-responsive, pH-sensitive, and other stimuli-responsive hydrogels, can undergo phase transitions in response to specific stimuli, thereby achieving optimal functionality. These hydrogels can fill the injured cartilage area, promote the proliferation and differentiation of chondrocytes, and expedite the repair of the damaged site. With advancements in cartilage tissue engineering materials research, intelligent responsive hydrogels offer a novel approach and promising potential for the treatment of cartilage injuries. CONCLUSION Intelligent responsive hydrogel is a kind of flexible, controllable, efficient, and stable polymer, which has similar structure and functional properties to articular cartilage, and has become one of the important biomaterials for cartilage repair. However, there is still a lack of unified treatment standards and simple and efficient preparation technology.
Hydrogels/therapeutic use* ; Cartilage, Articular/injuries* ; Tissue Engineering/methods* ; Humans ; Animals ; Chondrocytes/cytology* ; Biocompatible Materials/chemistry* ; Tissue Scaffolds/chemistry*

OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

OBJECTIVE: To investigate the effectiveness of digital three-dimensional (3D) assisted unilateral biportal endoscopy (UBE) in the treatment of highly isolated lumbar disc herniation (LDH) with translaminar approach. METHODS: The clinical data of 59 patients who met the selection criteria and underwent UBE treatment due to highly isolated LDH between January 2022 and December 2023 were retrospectively analyzed. Among them, 25 cases were treated with digital 3D assisted translaminar approach (observation group) and 34 cases were treated with interlaminar approach (control group). There was no significant difference in gender, age, disease duration, surgical segment, and preoperative visual analogue scale (VAS) score and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative blood loss, and lateral articular surface preservation rate were recorded and compared between the two groups. VAS score and ODI were used to evaluate the improvements of pain and function before operation and at 3 and 6 months after operation. The modified MacNab criteria was used to evaluate the effectiveness at last follow-up. RESULTS: One patient in the control group had dural tear, and the other patients had no nerve injury, infection, dural tear, or other related complications. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). Patients in both groups were followed up 6-13 months, with an average of 8.3 months. The lateral articular surface preservation rate in the observation group was significantly higher than that in the control group ( P<0.05). Three patients in the observation group and 2 patients in the control group had calf muscle venous thrombosis, which was cured after anticoagulant treatment with rivaroxaban and delayed exercise time. There was no recurrence or second operation during the follow-up period. The VAS score and ODI of the two groups at 3 and 6 months after operation significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two groups at each time point after operation ( P>0.05). At last follow-up, the effectiveness was evaluated according to the modified MacNab criteria, and there was no significant difference in the evaluation grade and excellent and good rate between the two groups ( P>0.05). CONCLUTION UBE via translaminar approach is safe and effective for the treatment of highly isolated LDH, which is beneficial to protect the facet joint, maintain spinal stability, and reduce soft tissue injury. With the assistance of digital 3D technique, preoperative planning can be performed accurately.
Humans ; Intervertebral Disc Displacement/diagnostic imaging* ; Lumbar Vertebrae/diagnostic imaging* ; Male ; Retrospective Studies ; Female ; Endoscopy/methods* ; Treatment Outcome ; Middle Aged ; Adult ; Imaging, Three-Dimensional ; Operative Time ; Pain Measurement

OBJECTIVE: To investigate the effectiveness of knee arthroscopy with wire anchor nailing composite double pulley technique in the treatment of anterior cruciate ligament (ACL) tibial avulsion fracture involving the anterior root of the lateral meniscus (LM). METHODS: Clinical data of 35 patients with ACL tibial avulsion fracture involving the anterior root of the LM admitted between January 2019 and September 2023 and met the selection criteria were retrospectively analysed. There were 20 males and 15 females; ages ranged from 10 to 57 years, with a mean of 29 years. The time from injury to surgery ranged from 3 to 20 days, with a mean of 9.6 days. Meyers-McKeever classification included 5 cases of type Ⅱ, 12 cases of type Ⅲ, and 18 cases of type Ⅳ. Preoperative anterior knee instability Lachman test and anterior drawer test were positive. The anterior root of the LM as well as the avulsion fracture block were fixed using suture anchor nails compounded with double pulley technique under arthroscopy. Postoperative X-ray films were performed to assess fracture healing; knee stability was assessed using the anterior drawer test and Lachman test, anterior laxity of the knee was measured by KT-2000, and knee function was assessed using the Lysholm score and the International Knee Documentation Committee (IKDC) score; at last follow-up, the recovery of the meniscus was assessed using the McMurry test and knee hyperextension test. RESULTS: All the patients were successfully operated, the operation time ranged from 56 to 78 minutes,with an average of 67.6 minutes, and there was no nerve or blood vessel injury during operation. Thirty-five cases were followed up 12-18 months with an average of 15.1 months. During the follow-up, there was no infection, knee stiffness, loosening of internal fixation, fracture displacement, or re-fracture. The fractures all healed, with a clinical healing time of 8-15 weeks, averaging 10.9 weeks. At last follow-up, 4 patients had weakly positive anterior drawer test and Lachman test, and the rest were negative; McMurry test and knee hyperextension test were negative; no patient complained of knee extension pain or straightening obstacles, and all the patients resumed their normal life or sports and labour; 16 patients with unclosed epiphyses did not have any epiphyseal injuries or growth disorders. Lysholm score, IKDC score, and KT-2000 anterior knee laxity at last follow-up significantly improved when compared with preoperative ones ( P<0.05). CONCLUSION The treatment of ACL tibial avulsion fracture involving the anterior root of the LM with suture anchor composite double pulley technique can effectively fix the anterior root of the LM while fixing the avulsion fracture block, and better restore the function and stability of the knee joint.
Humans ; Male ; Female ; Adult ; Arthroscopy/methods* ; Adolescent ; Retrospective Studies ; Tibial Fractures/surgery* ; Young Adult ; Middle Aged ; Fractures, Avulsion/surgery* ; Fracture Fixation, Internal/instrumentation* ; Anterior Cruciate Ligament Injuries/surgery* ; Child ; Treatment Outcome ; Suture Anchors ; Menisci, Tibial/surgery* ; Tibial Meniscus Injuries/surgery* ; Bone Nails ; Knee Joint/surgery*

OBJECTIVE: To investigate the short-term effectiveness of transtibial pull-out technique combined with side-to-side suture technique in treatment of complete radial tear of lateral meniscus body. METHODS: Between May 2020 and August 2023, 15 patients with complete radial tear of lateral meniscus body were repaired by arthroscopic transtibial pull-out technique combined with side-to-side suture technique. There were 11 males and 4 females, with an average age of 25.2 years (range, 15-43 years). Twelve cases were acute injuries and 3 were chronic injuries. All patients had tenderness in the lateral compartment of the knee. No abnormal alignment was observed on the X-ray films of the knee. MRI showed the complete radial tear of lateral meniscus body without associated injuries such as anterior cruciate ligament or cartilage. Preoperative Lysholm score was 44.5±6.4, International Knee Documentation Committee (IKDC) subjective score was 40.2±8.4, Tegner score was 1.3±1.1, and visual analogue scale (VAS) score for pain was 5.1±1.1. The operation time, incision healing, and complications such as vascular/nerve injury were recorded. During follow-up, the range of motion of the knee and tenderness in the lateral compartment of the knee were observed. The knee function and pain were evaluated using Lysholm score, Tegner score, IKDC subjective score, and VAS score. X-ray films and MRI of the knee were reexamined to assess knee degeneration. RESULTS: The operation time was 60-145 minutes (mean, 89.6 minutes). All incisions healed by first intention, and no complication such as vascular/nerve injury occurred. All patients were followed up 17-56 months (mean, 38.4 months). All patients had no knee extension limitation and 3 cases had tenderness in the lateral compartment of the knee. At last follow-up, the Lysholm score, IKDC subjective score, Tegner score, and VAS score for pain were 85.3±7.8, 82.1±15.7, 4.7±1.2, and 1.5±1.0, respectively, which were superior to those before operation ( P<0.05). Imaging reexamination showed that the meniscus was reset at 1 day after operation, and there was no sign of knee degeneration at last follow-up. CONCLUSION Transtibial pull-out technique combined with side-to-side suture technique can effectively treat the complete radial tear of lateral meniscus body and obtain good short-term effectiveness.
Humans ; Male ; Female ; Adult ; Tibial Meniscus Injuries/surgery* ; Adolescent ; Young Adult ; Arthroscopy/methods* ; Treatment Outcome ; Suture Techniques ; Tibia/surgery* ; Menisci, Tibial/surgery* ; Magnetic Resonance Imaging