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 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.
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.
ObjectiveTo explore the application value and operation skills of arthroscopic automatic reverse guide wire passer (hereinafter referred to as wire passer) in the posterior meniscus root reconstruction. Methods Between August 2015 and December 2020, 36 patients with posterior meniscus root tears were admitted. There were 16 males and 20 females, with an average age of 46 years (range, 26-66 years). There were 15 cases of sports injury and 21 cases of degenerative injury. The disease duration was 3-180 days, with a median of 28 days. The posterior root of the medial meniscus was injured in 29 cases, and the posterior root of the lateral meniscus was injured in 7 cases. The preoperative Lysholm score of the knee joint was 47.6±3.9, and the International Knee Score Committee (IKDC) score was 39.3±3.0. The meniscus was sutured by using wire passer under arthroscopy. During operation, the suture operation was evaluated according to the self-defined evaluation standard. Lysholm score and IKDC score were used to evaluate knee joint function. Results All meniscuses were sutured successfully by using wire passer. The operation time of suture was 5-15 minutes, with an average of 10 minutes. According to the self-defined evaluation standard, the suture operation was scored as 0-10, with an average of 5. After operation, except for 2 cases of incision fat liquefaction, the incisions of the other patients healed by first intention. All patients were followed up 1-3 years, with an average of 1.5 years. The Lysholm score was 88.2±2.1 and the IKDC score was 51.7±2.3 at 1 year after operation, showing significant difference when compared with preoperative ones (P<0.001). Fifteen cases underwent MRI re-examination, the results showed that the continuity and integrity of the posterior root had been restored. Conclusion Under arthroscopy, the wire passer for the posterior meniscus root reconstruction has the advantages of simple operation, reliable suture quality, and shorter operation time.
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.
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.
Objective To investigate the clinical application of periosteal autograft in repair of cartilage defect caused by osteoarthritis of knee. Methods From 1996 to 1999, 36 knees of cartilage defect of knee joint in 28 cases were treated. In the operation, the cracked degenerative cartilage was removed before free periosteum from tibia was transplanted to repair the defect, and the meniscuses in 8 knees of the 36 knees were reconstructed. After operation, early continuous passive movement was adopted for 4 weeks, and 8 knees with reconstruction ofthe meniscus were immobilized by plaster splint for 7 days after operation and before passive movement. All of the cases were followed up for 1 to 4 years before clinical evaluation in symptoms, signs and radiological findings. Results The general satisfactory rate was 86.1%, in which the function was excellent in 22 knees and good in 9 knees. Conclusion The periosteal autograft is a good choice for repairing cartilage defect due to osteoarthritis, with a satisfactory outcomein the short term.
Objective To review the details of the current effortsto reconstruct or replace the meniscus.Methods Three kinds of proceduresof reconstructing or replacing the meniscus were analyzed and evaluated by an extensive review of the latest literatures concerned. Results Three kinds of techniques were established to reconstruct the meniscus clinically, i.e., the allograft of the meniscus, meniscal reconstruction with the autotendon, and the meniscus scaffold. There were still a few defects in the meniscal replacement, and so the curative techniques would still be investigated. Conclusion Many efforts have been made to reconstruct the meniscus after its injury or its resection so as to prevent degeneration of the knee joint. The meniscal replacement has been employed for many years, but it has not worked so well. The establishment of an ideal replacement of the meniscus requires further studies. Therefore, reconstruction of the meniscus function is still a challenging problem to the surgeons concerned.