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 explore clinical effect of autologous osteochondral transplantation (AOT) in the treatment of recurrent anterior dislocation of the shoulder joint with glenoid cartilage defect in rabbits by establishing a model of recurrent anterior dislocation of the shoulder joint with < 20% glenoid cartilage defect in rabbits. METHODS: Twenty-four male New Zealand white rabbits, aged 6-month-old, weighed (2.69±0.17) kg were selected. The labrum of shoulder joint of rabbits was artificially destroyed to establish a model of recurrent anterior dislocation of shoulder joint with cartilage defect. They were divided into AOT surgery group and simple suture group, with 12 rabbits in each group. AOT group were underwent AOT surgery, while simple suture group was treated with simple Bankart suture for recurrent shoulder joint dislocation. At 6 and 12 weeks after operation, 6 rabbits between two groups were sacrificed for sampling. The dietary conditions, activity conditions, mental states of rabbits and healing conditions of grafts in the specimens were observed and compared between two groups. HE staining was used to observe cell creep, cell morphology, inflammatory cell infiltration, fibrochondrocytes and their arrangement. Masson staining was used to observe the formation and arrangement of collagen fibers; Safrane-green staining was used to observe the regeneration of articular cartilage, subchondral bone and bone tissue. Bone mineral density (BMD), bone volume (BV) and trabecular thickness (Tb.Th) between two groups were measured by Micro-CT to evaluate the remodeling of shoulder glenoid bone defects by autologous osteochondral cartilage. RESULTS: After different surgical interventions were carried out in both groups of rabbits, at 6 weeks after the operation, the abduction, extension, internal rotation and external rotation of the shoulder joint on the operated side showed limited range of motion compared with the contralateral side, while adduction and forward flexion showed no obvious abnormalities compared with the contralateral side. At 12 weeks after operation, the range motion of tshoulder joints in both groups of rabbits had returned to the state before modeling. The effects of HE staining, Masson staining and safrane-green staining at 12 weeks after operation in both groups were stronger than the staining results at 6 weeks after operation. Moreover, the results of HE staining, Masson staining and safranin fixation green staining in AOT group at 6 and 12 weeks after operation were all higher than those in simple suture group. Micro-CT scan results at 6 and 12 weeks after operation showed that BMD (0.427±0.014), (0.466±0.032) g·cm-3, BV(116.171±3.527), (159.327±3.500) mm3, and Tb.Th (0.230±0.006), (0.285±0.009) mm in AOT group, which were higher than those of simple suture group in BMD(0.358±0.011), (0.384±0.096) g·cm-3, BV(72.657±3.903), (118.713±3.860) mm3, and Tb.Th(0.204±0.009), (0.243±0.007) mm;and the differences were statistically significant (P<0.05). CONCLUSION AOT procedure could effectively promote osteogenesis and fibrocartilage regeneration in the cartilage defect area of the shoulder glenoid <20%, which is conducive to reshaping the structure of the shoulder glenoid.
Animals ; Rabbits ; Male ; Transplantation, Autologous ; Cartilage, Articular/injuries* ; Shoulder Dislocation/physiopathology* ; Bone Transplantation ; Shoulder Joint/surgery*

OBJECTIVE: To establish foot and ankle models of different lateral collateral ligament injuries of ankle joint, and conduct finite element analysis on, and to explore the force conditions of subtalar articular cartilage during foot inversion movements under different gait stages and under different loads. METHODS: A normal ankle CT scan of a 30-year-old male healthy volunteer (heighted 175 cm and weighted 60 kg) was selected. The CT images were imported into software such as Mimics 21.0, Geomajic 2017, and Solidworks 2017 respectively, extract the normal ankle bone model. Then, the foot and ankle finite element models of different lateral collateral ligament injuries of ankle joint were constructed and divided into anterior talofibular ligament(ATFL) rupture group, ATFL and calcaneo fibular ligament (CFL) rupture group, ATFL, CFL and posterior talofibular ligament (PTFL) rupture group, and control group with intact ligament function by ANSYS 2021. Corresponding horizontal and vertical loads and torques were applied respectively on tibia and talus according to the force conditions of different phases to simulate landing phase, neutral and off-ground phase in walking gait. The changes in stress distribution area and stress peak of subtalar articular cartilage in the loading phase, neutral phase and off-ground phase gaits among four groups were observed. Simulate varus sprain action, apply different loads of 600, 1, 800, and 4, 200 N respectively, and changes in stress distribution area and the stress peak of subtalar articular cartilage among four groups of models were observed. RESULTS: In the gait simulation, the stress results of loading phase in ATFL fracture group, ATFL and CFL fracture groups, ATFL, CFL and PTFL fracture groups, and control group were 0.889 54, 0.960 89, 1.139 20, and 0.722 64 MPa, respectively. The neutral response force results were 1.250 60, 1.358 50, 1.363 70, 1.246 40 MPa respectively;the results of corresponding forces off-ground phase were 1.029 90, 1.138 70, 1.145 90 and 0.832 40 MPa respectively. In the inversion simulation, the stresses of ATFL fracture group, ATFL and CFL fracture groups, ATFL, CFL and PTFL fracture groups, and control group under load of 600 N were 2.191 3, 2.208 5, 2.215 7, and 2.156 6 MPa respectively. The stresses under a load of 1 800 N were 7.134 7, 9.715 2, 10.064 0, and 7.107 0 MPa respectively;the stresses under a load of 4 200 N were 17.435 0, 25.309 0, 26.119 0 and 16.010 0 MPa respectively. CONCLUSION The lateral collateral ligament of ankle joint plays an important role in the stability of the subtalar joint, especially CFL plays an important role in restricting calcaneal varus. If these ligaments are damaged, it will cause instability of the subtalar joint and further lead to lesions in the subtalar articular cartilage. Relevant exercises should be reduced or the ligament injuries should be treated in a timely manner.
Humans ; Finite Element Analysis ; Male ; Adult ; Cartilage, Articular/physiopathology* ; Ankle Injuries/physiopathology* ; Ankle Joint/physiopathology* ; Biomechanical Phenomena ; Subtalar Joint/injuries* ; Tomography, X-Ray Computed

OBJECTIVE: To investigate the changes of knee joint kinematics after anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral positioner based on the apex of deep cartilage (ADC). METHODS: Between January 2021 and January 2022, a total of 40 patients with initial ACL rupture who met the selection criteria were randomly divided into the study group (using the personalized femoral positioner based on ADC design to assist ACL reconstruction) and the control group (not using the personalized femoral positioner to assist ACL reconstruction), with 20 patients in each group. Another 20 volunteers with normal knee were collected as a healthy group. There was no significant difference in gender, age, body mass index, and affected side between groups ( P>0.05). Gait analysis was performed at 3, 6, and 12 months after operation using Opti _ Knee three-dimensional knee joint motion measurement and analysis system, and the 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, internal and external displacement) and motion cycle (maximum step length, minimum step length, and step frequency) of the knee joint were recorded. The patients' data was compared to the data of healthy group. RESULTS: In the healthy group, the flexion and extension angle was (57.80±3.45)°, the varus and valgus angle was (10.54±1.05)°, the internal and external rotation angle was (13.02±1.66)°, and the anteroposterior displacement was (1.44±0.39) cm, the superior and inferior displacement was (0.86±0.20) cm, and the internal and external displacement was (1.38±0.39) cm. The maximum step length was (51.24±1.29) cm, the minimum step length was (45.69±2.28) cm, and the step frequency was (12.45±0.47) step/minute. Compared with the healthy group, the flexion and extension angles and internal and external rotation angles of the patients in the study group and the control group decreased at 3 months after operation, and the flexion and extension angles of the patients in the control group decreased at 6 months after operation, and the differences were significant ( P<0.05); there was no significant difference in the other time points and other indicators when compared with healthy group ( P>0.05). In the study group, the flexion and extension angles and internal and external rotation angles at 6 and 12 months after operation were significantly greater than those at 3 months after operation ( P<0.05), while there was no significant difference in the other indicators at other time points ( P>0.05). There was a significant difference in flexion and extension angle between the study group and the control group at 6 months after operation ( P<0.05), but there was no significant difference of the indicators between the two groups at other time points ( P>0.05). CONCLUSION Compared with conventional surgery, ACL reconstruction assisted by personalized femoral positioner based on ADC design can help patients achieve more satisfactory early postoperative kinematic results, and three-dimensional kinematic analysis can more objectively and dynamically evaluate the postoperative recovery of knee joint.
Humans ; Biomechanical Phenomena ; Knee Joint/surgery* ; Femur/surgery* ; Anterior Cruciate Ligament Injuries/surgery* ; Range of Motion, Articular ; Cartilage/surgery* ; Anterior Cruciate Ligament Reconstruction/methods*

OBJECTIVE: To obtain eripheral blood mesenchymal stem cells (PBMSCs) from sheep and rabbits by continuous mobilization of granulocyte colony-stimulating factor (G-CSF), and by comparing the success rates, cell yields and biological characteristics of the two sources of PBMSCs, and to provide the experimental basis for the preclinical study of PBMSCs transplantation to repair articular cartilage injury and cartilage tissue engineering. METHODS: Through morphological characteristics, flow cytometry analysis of its surface markers, and induction of trilineage differentiation of the two cells in vitro (ie: adipogenic differentiation, osteogenic differentiation, chondrogenic differentiation), the obtained cells were finally confirmed to be PBMSCs. The colony-forming units (CFUs) and the acquisition success rates of the two PBMSCs were counted and compared, and the production of the second generation of the two PBMSCs was counted and compared by hemocytometer, and the cell counting kit-8 was used to detect the doubling time of the two PBMSCs, and the results of trilineage differentiation were quantitatively analyzed by image processing. RESULTS: Microscopically, the PBMSCs of fusiform sheep and rabbits were arranged in fish group, and the second generation of sheep and rabbit PBMSCs expressed CD44 and CD90, but not CD34 and CD45. The induction of trilineage differentiation of the two cells in vitro were successful. The CFUs of primary sheep and rabbits PBMSCs were: 7.27±1.56, 5.73±1.62, and the success rate of acquisition of sheep and rabbits PBMSCs were 78.57% and 36.67%. The number of the second-generation sheep and rabbits PBMSCs that obtained per milliliter of peripheral blood were: 29 582±2 138, 26 732±2 286, and the cell doubling times (h) of the third-generation sheep and rabbits PBMSCs were: 22.32±0.28, 33.21±0.64, the cell doubling time (h) of the fourth generation sheep and rabbits PBMSCs were: 23.62±0.56, 35.30±0.38, and the quantitative lipid ratio of sheep and rabbit PBMSCs were: 7.77%±3.81%, 17.05%±1.52%, sheep and rabbit PBMSCs chondroglobus acid mucopolysaccharide positive ratios were: 11.67%±0.53%, 8.14%±0.57%. There were statistical differences among the above groups (P < 0.05). CONCLUSION The continuous mobilization of G-CSF to obtain sheep PBMSCs is more efficient. Sheep PBMSCs have more abundant yield and stronger proliferation ability.Sheep PBMSCs can produce more acidic mucopolysaccharides and have lower adipogenic abi-lity under appropriate conditions. Sheep PBMSCs have good research prospects in repair of articular cartilage injury with autologous stem cell transplantation and preclinical animal in vivo experiment of cartilage tissue engineering.This experiment provides further experimental basis for this kind of research.
Sheep ; Rabbits ; Animals ; Osteogenesis ; Hematopoietic Stem Cell Transplantation ; Cells, Cultured ; Transplantation, Autologous ; Mesenchymal Stem Cells ; Cell Differentiation ; Cartilage, Articular/injuries* ; Granulocyte Colony-Stimulating Factor

After the articular cartilage injury, the metabolic level is increased during the progressive degeneration, the chondrocytes secrete a variety of inflammatory factors, and the original cell phenotype is gradually changed. For a long time, a large number of researchers have done a lot of researches to promote anabolism of chondrocytes and to maintain the stability of chondrocyte phenotype. There are many molecular signaling pathways involved in the process of promoting cartilage repair. This review focuses on the key signaling molecules in articular cartilage repair, such as transforming growth factor-beta and bone morphogenetic protein, and reveals their roles in the process of cartilage injury and repair, so that researchers in related fields can understand the molecular mechanism of cartilage injury and repair widely and deeply. Based on this, they may find promising targets and biological methods for the treatment of cartilage injury.
Bone Morphogenetic Proteins ; physiology ; Cartilage, Articular ; growth & development ; injuries ; Chondrocytes ; physiology ; Humans ; Regeneration ; Signal Transduction ; Transforming Growth Factor beta ; physiology

Chondral injuries are short of self-healing ability and need to surgical repair after articular cartilage injury. Conventional treatment includes debridement and drainage under arthroscope, micro-fracture, osteochondral autograft transplantation (OATS), mosaiplasty and osteochondral allografts (OCA), autologous chondrocyte implantation (ACI). Debridement and drainage could remove pain factor, and has advantages of simple operation, wide clinical application and early clinical effect. Micro-fracture and osteochondral autograft transplantation is suitable for small area of cartilage repair, while the further effect showed that fibrous cartilage permeated by drill could decrease postoperative clinical effect. Osteochondral autograft transplantation has better advantages for reconstruction complete of wear-bearing joint. Autologous chondrocyte implantation and allogeneic cartilage transplantation are suitable for large area of cartilage defect, postoperative survival of allogeneic cartilage transplantation is effected by local rejection reaction and decrease further clinical effect. Cartilage tissue engineering technology could improve repair quality of autologous chondrocyte implantation, and make repair tissue close to transparent cartilage, but has limit to combined subchondral bone plate, reactive bone edema, bone loss and bad axis of lower limb. New technology is applied to cartilage injury, and has advantages of less trauma, simple operation, rapid recover, good clinical effect and less cost;and could be main method for treat cartilage injury with surgical repair technology. How to improve repair quality with compression resistance and abrasive resistance are expected to be solved.
Cartilage, Articular ; injuries ; surgery ; Chondrocytes ; transplantation ; Humans ; Knee Injuries ; surgery ; Knee Joint ; surgery ; Transplantation, Autologous

Antegrade transmalleolar drilling method is one of the options for the treatment of osteochondral lesion of talus (OLT). We present five patients who underwent tibial drilling for treatment of OLT and later developed distal tibial cystic formation induced by cartilage opening or heat necrosis during drilling. Antegrade transmalleolar drilling can be a possible option for the treatment of OLT if the lesion is not easily reachable; however, other viable treatment should be considered due to its possibility of distal tibial pathologic change.
Adult ; Ankle Joint/surgery ; Cartilage, Articular/*surgery ; Female ; Humans ; *Iatrogenic Disease ; Male ; *Musculoskeletal Diseases/etiology/surgery ; *Orthopedic Procedures/adverse effects/methods ; Talus/*surgery ; *Tibia/injuries/surgery ; Young Adult

OBJECTIVETo study the overexpression of Sox9 gene on rabbit bone marrow mesenchymal stem cells for repairing articular cartilage injury in vivo.

METHODSRabbit bone marrow mesenchymal stem cells (BMSCs) were transduced with lentivirus vector containing Sox9 gene and then cartilage specific molecule was detected by RT-PCR in vitro. Total 48 knee joints of 24 mature New Zealand white rabbits were randomly divided into 3 groups according to different defect treatment. After animals anesthesia,a full-thickness cylindrical cartilage defect of 4 mm diameter and 3 mm deep was created in the patellar groove using a stainlesssteel punch. Meanwhile, the transfected cells were implanted to repair the rabbit model with full-thickness cartilage defects. Cartilage defects tissue was observed with light microscope, electron microscope, HE and immunohistochemistry staining to assess the repair of defects by the complex at 6 weeks or 12 weeks after the implantation.

RESULTSAt 3 days after the transfection, Sox9 gene expression was highest and Sox9 gene expression decreased with the increase of time. At 3 days after the transfection, the expression of collagen type II began and reached the peak at 14 days. It showed that the bone marrow mesenchymal stem cells went into chondrogenic differentiation after transfected by Sox9 gene. Histological observation showed that at 6 weeks after the operation, the defects in the experimental group was filled with hyaline like cartilage tissue, 12 weeks after operation,the defects of cartilage and subchondral bone had satisfactory healing. Both at 6 and 12 weeks postoperatively, the defects were filled with fibrous tissues in control groups. Meanwhile, immunohistochemical staining of sections with type II collagen antibodies showed the proteins in the regenerated tissue stained positive for type II collagen and stronger than the control groups. The histological scoring system indicated that the cartilage repair of experiment groups were better than the two control groups with statistical significances.

CONCLUSIONOverexpression of Sox9 gene on rabbit bone marrow mesenchymal stem cells (BMSCs) promote the repair of cartilage defect.

Animals ; Bone Marrow Cells ; metabolism ; Bone Marrow Transplantation ; Cartilage, Articular ; injuries ; metabolism ; Cell- and Tissue-Based Therapy ; Female ; Genetic Vectors ; genetics ; metabolism ; Humans ; Lentivirus ; genetics ; metabolism ; Male ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; metabolism ; Osteoarthritis ; genetics ; metabolism ; therapy ; Rabbits ; SOX9 Transcription Factor ; genetics ; metabolism ; Tissue Engineering

OBJECTIVETo analyze the 3 dimensional-fat suppression-spoiled gradient-recalled acquisition (3D-FS-SPGR) sequence in the diagnosis of knee articular cartilage injury.

METHODSA total of 56 knee osteoarthritis patients (26 males, 30 females, ages 52-73 years, mean 61.8 years) treated in Department of Orthopedics, Chinese People's Liberation Army General Hospital between June 2013 and May 2014 were involved in this study. All patients underwent knee MRI, plus 3D-FS-SPGR sequence, arthroscopic exploration, and in contrast to the results of MRI results analysis, evaluation 3D-FS-SPGR and conventional sequence of cartilage damage consistent with the arthroscopic accuracy.

RESULTSDivided 56 knee joints into 336 cartilage articular surface, included 55.1% normal articular surface, 21.4% early osteoarthritis and 23.5% advanced osteoarthritis. The accordance of 3D-FS-SPGR sequence grading and arthroscopic was 90.2%. The sensitivity of 3D-FS-SPGR sequence was 93.1%, specificity was 98.3%, and Kappa value was 0.849. The sensitivity of T2WI sequence was 84.4%, specificity was 96.9%, and the Kappa value was 0.671.

CONCLUSIONFor unicompartment osteoarthritis , MRI 3D-FS-SPGR sequence is effective in sensitivity and specificity of cartilage damage.

Aged ; Arthroplasty ; Arthroscopy ; Cartilage, Articular ; Female ; Humans ; Knee Injuries ; diagnosis ; Knee Joint ; physiopathology ; surgery ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Orthopedic Procedures ; Osteoarthritis, Knee ; surgery ; Preoperative Care ; Sensitivity and Specificity