Objective To study degradation of the antigen-extracted meniscus in PBS solution with no enzyme or with different enzymes. Methods Four types of enzymes (collagenase, hyaluronidase, trypsin, papain) were used to enzymolyze the antigen-extracted meniscus and the fresh meniscus for 3, 7, 15 and 30 days (37℃). The antigenextracted meniscus and the fresh meniscus were immersed in PBS solution (37℃) for 30 days. Weight loss measurement, UV spectrophotometry, and scanning electron microscopy (SEM) were used to characterize the degraded materials. Results The two types of the materials were remarkably digested under the enzymes, especially under trypsin. The degradation curves showed that the antigen-extracted meniscus was enzymolyzed less than the fresh meniscus. The degradation products were grouped as amino, peptide, and polyose by the analysis. Both of the materials could hardly behydrolyzed in PBS solution without the enzymes. The four different enzymes had different surface morphologies under the examination of SEM. Conclusion The antigen-extracted meniscus is enzymolyzed more slowly than the fresh meniscus in vitro, and the result can be used as a guideline to the further research.
OBJECTIVE To investigate the effect of meniscus suture on meniscus healing which included healing time and healing pattern. METHODS Fourty healthy rabbits were adopted in this study. The model of meniscus injury was made by a longitudinal incision at the medial meniscus of the left knee. The rabbits were divided into two groups, the experimental group was treated by meniscus suture and the control group was unsutured. After operation, the meniscus samples were collected periodically and observed by gross, light and electronic microscope to analysis the meniscus healing. RESULTS The injured meniscus was healed gradually and completely at the sixth week in the experimental groups. More fibroblasts and less fibrocartilage cells could be observed in the healed meniscus. Oppositely, there was no meniscus healing in the control group and the edge of injured meniscus was sealed by epithelioid cells. CONCLUSION The meniscus suture can accelerate the healing process of meniscus injury. Besides, early suture make the injured meniscus correctly positioned to ensure the normal healing process.
Objective To investigate the result of the arthroscopicrepair of the meniscus tears with the absorbable sutures. Methods From June 1998 to May2003，the meniscus tears in 110 patients (78 males, 32 females; aged 1466 years, averaged 27.5 years) were repaired with absorbable sutures under an arthroscope. In the patients, there were 93 vertical split injuries, 12 transverse split injuries, and 5 hidden split injuries. There were 78 tears in the lateral margin of the meniscus, 23 tears in the anterior angle of the meniscus, and 9 tears in the posterior angle of the meniscus. Ninetyone patients had 2 sutures, 13 patients had 4 sutures, 4 patients had 6 sutures, and 2 patients had 8 sutures. The rehabilitation program was performed in all the patients postoperatively, and the clinical outcome was observed. The Lysholm score was 57±12 preoperatively. Results Thefollow-up for an average of 26 months (range,12-67 months) showed that 3 patients had a light pain on exertion in the surgically-treated knee;1 patientunderwent an operation again for recurrence of the symptoms due to a failure in the healing of the meniscus tear, so a second arthroscopic operation was performed; and the other patients had a satisfactory result with an excellent knee function. The Lysholm score was 92±7 after operation. Conclusion The arthroscopic repair of the meniscustears has advantages of safety and reliability in the suturing and easier to perform. The repaired meniscus can play much better physiological and biomechanical functions, and will not limit the normal movement of the meniscus during the knee flexion after the sutures are absorbed.
ObjectiveTo establish a classification model based on knee MRI radiomics, realize automatic identification of meniscus tear, and provide reference for accurate diagnosis of meniscus injury. Methods A total of 228 patients (246 knees) with meniscus injury who were admitted between July 2018 and March 2021 were selected as the research objects. There were 146 males and 82 females; the age ranged from 9 to 76 years, with a median age of 53 years. There were 210 cases of meniscus injury in one knee and 18 cases in both knees. All the patients were confirmed by arthroscopy, among which 117 knees with meniscus tear and 129 knees with meniscus non-tear injury. The proton density weighted-spectral attenuated inversion recovery (PDW-SPAIR) sequence images of sagittal MRI were collected, and two doctors performed radiomics studies. The 246 knees were randomly divided into training group and testing group according to the ratio of 7∶3. First, ITK-SNAP3.6.0 software was used to extract the region of interest (ROI) of the meniscus and radiomic features. After retaining the radiomic features with intraclass correlation coefficient (ICC)>0.8, the max-relevance and min-redundancy (mRMR) and least absolute shrinkage and selection operator (LASSO) were used for filtering the features to establish an automatic identification model of meniscus tear. The receiver operator characteristic curve (ROC) and the corresponding area under the ROC curve (AUC) was obtained; the model performance was comprehensively evaluated by calculating the accuracy, sensitivity, and specificity. Results A total of 1 316-dimensional radiomic features were extracted from the meniscus ROI, and the ICC within the group and ICC between the groups of the 981-dimensional radiomic features were both greater than 0.80. The redundant information in the 981-dimensional radiomic features was eliminated by mRMR, and the 20-dimensional radiomic features were retained. The optimal feature subset was further selected by LASSO, and 8-dimensional radiomic features were selected. The average ICC within the group and the average ICC between the groups were 0.942 and 0.920, respectively. The AUC of the training group was 0.889±0.036 [95%CI (0.845, 0.942), P<0.001], and the accuracy, sensitivity, and specificity were 0.873, 0.869, and 0.842, respectively; the AUC of the testing group was 0.876±0.036 [95%CI (0.875, 0.984), P<0.001], and the accuracy, sensitivity, and specificity were 0.862, 0.851, and 0.845, respectively. ConclusionThe model established by the radiomics method has good automatic identification performance of meniscus tear.
To design a new suit of instruments for meniscal suture with tondon, and then authenticate their feasibil ity and the therapeutic effect of the new technique. Methods Instruments were developed, including new ones and others which was improved according to the current instruments. From October 2005 to December 2006, 45 patients with meniscal injury were treated by meniscal suture with tendon. There were 29 males and 16 females, aged 17-40 years (mean 28 years). Injury was caused by sports in 33 cases, by traffic accident in 5 cases, by fall ing in 3 case and others in 4 cases. The disease course was 3 days to 6 months (mean 2 months). There were 23 cases accompanying with anterior cruciate l igament injury and 6 cases accompanying with posterior cruciate l igament injury. E-MRI showed 2 cases of degree II and 43 cases of degree III. Arthroscope showed that injury was at medial meniscus in 39 cases and at lateral meniscus in 6 cases. The pre-operationalLysholm score was 53.0 ± 10.3. Autogeneic or xenogenic tendon was made into suture l ine guided by stitch at the two ends. Thetherapeutic effect of the new technique was authenticated by cl inical results, including the change of symptoms and phy sical signs, and by comparing the pre-operational Lysholm score with the post one. Results Nineteen pieces of instruments weredeveloped. All the operation were successful, with no harm to nerves and vessels. The follow-up was 6 months to 24 mo nths (mean15 months). At the last follow-up, all the symptoms disappeared, including pain, swell ing and locking, etc. The Lysholm sc oreafter 6 months of operation was 87.8 ± 9.2, showing statistically significant difference when compared with per-operati on ( P lt; 0.01). Conclusion It is feasible to suture injured menisci with the new instruments and technique. It is an effective way to repair menisci with tendon according to the short-term results.
Objective To examine the research status and predict trends in ME research findings from 1997-2023 on a global scale. Methods Web of Science Core Collection database was searched for original articles on ME published between 1997 and 2023, and then analyzed using CiteSpace, VOSviewer and the Online Analysis Platform of Literature Metrology to map scientific knowledge. Results A total of 748 articles were eventually included. The number of ME publications increased year by year, with the USA being the most productive country. Osteoarthritis, MRI, medial meniscus posterior root repair, biomechanical evaluation, lateral meniscus allograft transplantation, radiographic joint space narrowing are the high frequency keywords in co-occurrence cluster analysis and cocited reference cluster analysis. Medial meniscus posterior root tear and lateral meniscus allograft transplantation are current and evolving research hotspots in citation burst detection analysis. Conclusions The understanding of ME has been improved significantly during the past decades. Current research focuses on optimizing surgical repair methods and obtaining long-term follow-up outcomes for medial meniscal posterior root repair and developing methods to reduce ME after lateral meniscal allograft, as well as they are the highlights of future research on ME.
Objective To review the current development in meniscus tissue engineering. Methods Recent literature concerning the development of the meniscus tissue engineering was extensively reviewed and summarized. Results Recent researches mainly focus on: selection of seed cells and research of their potential of differentiation into chondrocytes; selection of scaffold materials and research of their mechanical properties; cytokines and their mechanisms of action. Conclusion Many achievements have been made in meniscus tissue engineering. Most important topics in future research include: finding seed cells that are adapted to physiological process, are easy to culture, and have higher chondrogenic differentiation ability; looking for necessary cytokines and their mechanisms of action; finding scaffold meterials with b morphological plasticity, no antigenicity, good degradability, and mechanical property close to normal meniscus.
Objective To compare biological characteristics between articular chondrocyte and meniscal fibrochondrocyte cultured in vitro andto investigate the possibility of using cultured cartilage as a substitute for meniscus.Methods Chondrocytes isolated from articular cartilage and meniscus of rabbits aged 3 weeks were respectively passaged in monolayer and cultured in centrifuge tube. Cartilages cultured in centrifuge tube and meniscus of rabbit aged 6 weeks were detected by histological examination and transmission electron microscopy. Growth curves of articular chondrocytes and meniscalfibrochondrocytes were compared; meanwhile, cell cycles of articular chondrocytes and meniscal fibrochondrocytes in passage 2and 4 were separately measured by flow cytometry.Results Articular chondrocytes in passage 4 were dedifferentiated. Articular chondrocytes formed cartilage 2 weeks after cultivation in centrifuge tube, but meniscal fibrochondrocytes could not generate cartilage. The differences in ultrastructure and histology obviously existed between cultured cartilage and meniscus; moreover, apoptosis of chondrocytes appeared in cultured cartilage. Proportion of subdiploid cells in articular chondrocytes passage 2 and 4 was markedly higher than that in passage 2 and 4 fibrochondrocytes(Plt;0.05). Conclusion Meniscal fibrochondrocytes can not form cartilage after cultivationin centrifuge tube, while cartilage cultured in centrifuge tube from articular chondrocytes can not be used as graft material for meniscus. Articular cartilage ismarkedly different from meniscus.
Objective To investigate the treatment and therapeutic efficacy of intra-articular meniscal cysts by arthroscopy. Methods From January 2005 to December 2009, 9 cases of intra-articular meniscal cysts were treated by arthroscopy, including 5 males and 4 females, with an average age of 33.8 years (range, 24-46 years). Six patients suffered in left knees, 3 in right ones. Just 1 case had trauma history, the others had no obvious predisposing causes. The average course of the disease was 24.2 months (range, 4-36 months). The Lysholm score was (74.2 ± 11.6) points. Arthroscopy showed that the locations of cysts were the anterior horn of lateral meniscus in 8 cases and the anterior horn of medial meniscus in 1 case; all being single cyst (of them, 3 being multilocular cyst). Results All incisions healed primarily with no compl ications of infection and joint effusion. All 9 patients were followed up from 3 to 48 months with an average of 12.7 months. Preoperative symptoms disappeared or reduced and the range of motion of the knee returned to normal. TheLysholm score was (95.1 ± 3.4) points after 3 months of operation, showing significant difference (P lt; 0.01) when compared with the socre before operation. According to assessment standard described by Choy, the treatment outcome was excellent in 6 cases, good in 2 cases, and general in 1 case; the excellent and good rate was 88.9%. No recurrence was found during follow-up. Conclusion Arthroscopic surgery shows the advantages to maintain good function of knee for the treatment of meniscal cyst, it is the best choice for intra-articular meniscal cysts because of its mini-trauma, rapid recovery, thorough treatment and less recurrence. Simultaneously, partial or tatol meniscectomy or menicus repairing under arthroscopy is performed.
Objective To explore the effects of the basic fibroblast growth factor（bFGF） gene transfection on the meniscal fibrochondrocytes with the reconstructed lentivirus and to observe the response of the meniscal fibrochondrocytes to the bFGF gene transfection. Methods The cultured meniscal fibrochondrocytes were isolated from the same 3-monthold New Zealand rabbit. The cultured first-generation meniscal fibrochondrocytes were divided into 3 groups:Group A (experimental group), Group B (control group), and Group C (blank group). Each group comprised the cells in a 24hole flask in which each hole contained 2×104 cells. At the confluence of 60%, the fibrochondrocytes in Group A were cultured with the reconstructed lentivirus carrying the bFGF gene. The fibrochondrocytes in Group B were cultured with the lentivirus carrying no bFGF gene. The fibrochondrocytes in Group C were cultured without any intervention. After 48 h, the cell cycle, the collagen synthesis ability, the expression of bFGF, and the cell proliferation ability in each group were investigated. Results In Group A, the bFGF expression of 870±60 pg/ml was detected in the cells 48 h afterthe co-culture; however, in Group B and Group C, no expression of bFGF was found. After the co-culture for 6 days, the results of the MTT colorimetry revealed that the cells in Group A had an absorbtance of 0.427±0.037, which had a significant difference when compared with that in Group B and Group C (0.320±0.042,0.308±0.034,Plt;0.01). The cell cycle was significantly shorter in GroupA than in Group B and Group C (Plt;0.05); The durations of G1, S and G2M of the cells in Group A were 16.28, 12.60 and 11.04 h, but those in Group B and Group C were 23.61, 16.90, 21.33 h and 21.56, 19.80, 21.41 h, respectively. The disintegration per minute of the cells was significantly greater in Group A than in Group B and Group C (7281.69±805.50 vs 5916.40±698.11 and 5883.57±922.63，Plt;0.05). Conclusion The lentivirus vector can transfer the bFGF gene into the meniscal fibrochondrocytes, resulting in an increase of the cell proliferation and the collagen synthesis.