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 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 elucidate the latest research progress and application of tissue engineered meniscus. Methods The literature concerning the advance in tissue engineered meniscus was extensively reviewed, then closely-related issues including seed cells, scaffolds, and bioreactors were analyzed. Results With more and more attention being paid to meniscus tissue engineering, different approaches and strategies for seed cells, scaffolds, and bioreactors have contributed to the generation of meniscal constructs, which are capable of restoring meniscal lesions to some extent, but translating successes in basic science research to clinical application is still limited. Conclusion More research for the optimal combination of the appropriate cell source, the scaffold type, and the proper physical and chemical factors for the stimulation of cells differentiation into tissue with optimal phenotypes in tissue engineered meniscus is still in needed, but the overall future looks promising.
ObjectiveTo summarize the mid-term effectiveness of arthroscopic anterior cruciate ligament (ACL) reconstruction combined with meniscus allograft transplantation.MethodsA clinical data of 21 patients treated with arthroscopic ACL reconstruction and meniscus allograft transplantation and followed up more than 5 years between February 2007 and December 2014 was retrospectively analyzed. There were 12 males and 9 females, aged from 18 to 45 years, with an average age of 23.5 years. The cause of injury was sport sprain in 15 cases, falling in 4 cases, and traffic accident in 2 cases. The time from injury to operation ranged from 2 to 36 months, with an average of 12 months. Among them, 15 patients underwent previous meniscectomy, with an average interval of 1.6 years (range, 3 months to 6.5 years). All patients were primary ACL reconstruction. Preoperative anterior drawer test, Lachman test, and pivot shift test were positive. Lysholm score was 43.6±10.2. International Knee Documentation Committee (IKDC) score was 60.50±14.06. Of the 21 patients, 10 were gradeⅠ-Ⅱcartilage injuries and 11 were grade Ⅲ cartilage injuries according to MRI. ResultsAll patients were followed up 5.1-7.8 years, with an average of 5.5 years. There were 2 cases of numbness of lower extremity, 3 cases of slight exudation of incision, 2 cases of articular movement bounce, 5 cases of mild joint swelling and pain after exercise. At last follow-up, Lachman tests were negative in 18 cases and positive in 3 cases; anterior drawer tests were negative in 19 cases and positive in 2 cases; pivot shift tests were negative in all cases. Lysholm score was 84.5±16.5 and IKDC score was 85.25±4.60, which were significantly higher than those before operation (P<0.01). The flexion and extension of the affected knee joint were (128±13) and (3±7)°, respectively, which were smaller than those of the healthy knee joint [(133±15), (0±5)°] (P<0.01). The results of KT-1000 test showed that when knee flexion was 30 and 90°, tibial anterior displacement of affected side [(2.35±1.20), (1.60±1.15) mm] were not significantly different from those of healthy side [(1.20±1.10), (1.10±1.03) mm] (P>0.01). MRI showed that the ACL graft was in normal position and meniscus survived well. Cartilage injuries were gradeⅠ-Ⅱ in 18 cases and grade Ⅲ in 3 cases. ConclusionFor patients with severe meniscus injury and ACL rupture, ACL reconstruction combined with meniscus allograft transplantation can restore the stability of the joint, recover the meniscus function which is conducive to the protection of articular cartilage and obtain satisfactory mid-term effectiveness.
ObjectiveTo evaluate the effectiveness of arthroscopically assisted treatment of posterior cruciate ligament (PCL) tibial eminence avulsion fractures associated with meniscus posterior horn tear. MethodsBetween January 2012 and December 2014, 21 patients with PCL avulsion fracture and meniscus posterior horn tear were arthroscopically treated with polyester suture and hollow screw fixation. There were 10 males (10 knees) and 11 females (11 knees), aged 14-53 years (mean, 35.7 years). The causes included sport injury in 11 cases, traffic accident injury in 9 cases, and daily life injury in 1 case. Based on the anteroposterior and lateral X-ray films, CT, and MRI, PCL avulsion fractures were diagnosed, and 2 cases had anterior cruciate ligament avulsion fractures. The results of posterior drawer test were positive in all patients, with no end point in 14 cases and with soft end point in 7 cases; all patients showed tibial sink. The preoperative International Knee Documentation Committee (IKDC) score and Lysholm score were 46.5±5.5 and 43.3±4.5 respectively. The time from injury to operation was 6-22 days (mean, 10 days). ResultsThe operation time was 60-100 minutes (mean, 75 minutes). Primary healing of incision was obtained in all patients, without no complication of infection. The mean follow-up time was 27.4 months (range, 12-46 months). The results of posterior drawer test were negative in 19 cases, and positive in 2 cases (having hard end point). Tibial sink disappeared. At last follow-up, X-ray film showed good healing of fracture, and no displacement. The patients had no locking knee, snapping or tenderness of joint space, and the Mcmurray sign was negative; the IKDC score and Lysholm score were significantly improved to 92.0±2.5 and 92.7±2.6 respectively (t=-39.903, P=0.000; t=-43.242, P=0.000). The range of motion was normal in 20 patients (0-130°) except 1 patient having limited flexion (0-80°), whose range of motion returned to 0-120° after release. ConclusionThe arthroscopic fixation technique has satisfactory results for the reduction and fixation of PCL avulsion fracture associated with meniscus posterior horn tear because of easy operation, firm fixation, and economic price.
ObjectiveTo manufacture a polycaprolactone (PCL)/type Ⅰ collagen (COL Ⅰ) tissue engineered meniscus scaffold (hereinafter referred to as PCL/COL Ⅰ meniscus scaffold) by three-dimensional (3D) printing with low temperature deposition technique and to study its physicochemical properties.MethodsFirst, the 15% PCL/4% COLⅠ composite solution and 15% PCL simple solution were prepared. Then, 15% PCL/4% COL Ⅰmeniscus scaffold and 15% PCL meniscal scaffold were prepared by using 3D printing with low temperature deposition techniques. The morphology and microstructure of the scaffolds were observed by gross observation and scanning electron microscope. The compression modulus and tensile modulus of the scaffolds were measured by biomechanical test. The components of the scaffolds were analyzed by Fourier transform infrared spectroscopy (FTIR). The contact angle of the scaffold surface was measured. The meniscus cells of rabbits were cultured with the two scaffold extracts and scaffolds, respectively. After cultured, the cell proliferations were detected by cell counting kit 8 (CCK-8), and the normal cultured cells were used as controls. Cell adhesion and growth of scaffold-cell complex were observed by scanning electron microscope.ResultsAccording to the gross and scanning electron microscope observations, two scaffolds had orientated 3D microstructures and pores, but the surface of the PCL/COLⅠ meniscus scaffold was rougher than the PCL meniscus scaffold. Biomechanical analysis showed that the tensile modulus and compression modulus of the PCL/COL Ⅰ meniscus scaffold were not significantly different from those of the PCL meniscus scaffold (P>0.05). FTIR analysis results showed that COL Ⅰ and PCL were successful mixed in PCL/ COL Ⅰ meniscus scaffolds. The contact angle of PCL/COLⅠ meniscus scaffold [(83.19±7.49)°] was significantly lower than that of PCL meniscus scaffold [(111.13±5.70)°] (t=6.638, P=0.000). The results of the CCK-8 assay indicated that with time, the number of cells cultured in two scaffold extracts showed an increasing trend, and there was no significant difference when compared with the control group (P>0.05). Scanning electron microscope observation showed that the cells attached on the PCL/ COL Ⅰ meniscus scaffold more than that on the PCL scaffold.ConclusionPCL/COLⅠmeniscus scaffolds are prepared by 3D printing with low temperature deposition technique, which has excellent physicochemical properties without cytotoxicity. PCL/COLⅠmeniscus scaffold is expected to be used as the material for meniscus tissue engineering.
Objective To observe the changes of force bearing area and pressures of the rabbit tibiofemoral contact area and the biomechanical reconstruction level of joint after meniscal allograft. Methods A total of 28 Japanese rabbits were involved, weighing 3.0-3.5 kg, male or female. Of 28 rabbits, 7 were selected as meniscus donors, the remaining 21 rabbits were randomized into group A (n=7), group B (n=7), and group C (n=7). Group A underwent single knee opening and suturing, group B underwent medial meniscus excision and suturing, and group C underwent medial meniscus allograft after medial meniscus excision and suturing. The rabbits were sacrified at 12 weeks after operation for biomechanical observation through biomechanical machine and color imaging system. The meniscus tissue specimens were harvested from groups A and C to perform histological and immunohistochemical staining. Results After operation, all rabbits in 3 groups survived to the end of experiment. There were significant differences in the force bearing area and pressures at 0-90° flexion between group B and groups A, C (P lt; 0.05) at 12 weeks, showing no significant difference between group A and group C (P gt; 0.05); and there were significant differences in the force bearing area and pressures at 120° flexion among 3 groups (P lt; 0.05). The histological observation showed that the number of cartilage cells and collagen fibers returned to normal in group C, and the immunohistochemical staining showed that transplanted meniscus of group C contained large amounts of collagen fibers consisting of collagen type I and collagen type II. After 12 weeks of operation, the collagen type I contents were 0.612 5 ± 0.059 8 in group A and 0.587 2 ± 0.063 9 in group C, showing no significant difference (t=0.765, P=0.465); the collagen type II contents were 0.772 4 ± 0.081 5 and 0.814 3 ± 0.051 7, respectively, showing no significant difference (t= —0.136, P=0.894). Conclusion The allograft of rabbit meniscus can significantly increase the force bearing area of the tibiofemoral contact area and reduce the average pressure. Therefore, biomechanically speaking, the meniscus allograft can protect the articular cartilage and reconstruct the biomechanical balance.
Objective To summarize the characteristic manifestations in the middle and old aged people with meniscus injury and the outcome of the treatment under the arthroscope. Methods Fifty-two patients, aged 52-58 years, with meniscus injury to a total of 57 knee joints, were diagnosed and treated under the arthroscope. The history of their knee diseases was 1-21 years. Horizontal tearsoccurred in 19 knee joints, degenerative tears in 13 knee joints, complex tears in 9 knee joints, longitudinal tears in 5 knee joints, oblique tears in 4 knee joints, radial tears in 4 knee joints, and flap tears in 3 knee joints. Three meniscus tears were sutured and 54 meniscus tears were cut fully or partly under thearthroscope. Results All the postoperative patients were followed up for 6-15 months, and the average follow-up period after operation was 9 months. According to the DONG Tianxiang’s standards for the therapy under the arthroscope, the excellent result was achieved in 39 knee joints, good in 12 knee joints, and fair in 6 knee joints, with no failure. The excellent and good rate was 89.5%. Conclusion The clinical manifestations of meniscus injury are not typical in the middle and old aged people. The therapeutic effect with the help of the arthroscope is satisfactory with an advantage of minimal traumatic invasiveness to the knee joint.
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.