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 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.
ObjectiveTo investigate the medium-term effectiveness of both side stereo suture for meniscus bucket handle tear under arthroscopy. MethodsBetween January 2009 and December 2012, 38 patients with combined injury of meniscus bucket handle tear underwent arthroscope surgery by the method of both side stereo suture. There were 26 males and 12 females with an average age of 32 years (range, 19-42 years). The injury causes included sports injury in 21 cases, traffic accident injury in 11 cases, and other trauma in 6 cases. The left knee was involved in 15 cases and the right knee in 23 cases. The interval between injury and operation was 2 days to 6 months (mean, 2.5 months). MRI examination showed meniscus injury at grade Ⅲ, including 22 cases of internal injury and 16 cases of lateral injury. The Barrett standard, Lysholm score of knee joint, and joint mobility were used to assess the function recovery of the knee joint. ResultsAll incisions healed primarily with no complication. All cases were followed up 24.5 months on average (range, 18-36 months). Based on the Barrett standard, meniscus bucket handle tear was successfully repaired in all cases. The Lysholm scores and range of motion of the knee at 6 months, 12 months, and last follow-up were significantly better than preoperative ones (P<0.05). ConclusionThe both side stereo suture of meniscus bucket handle tear under arthroscopy has an excellent medium-term effectiveness, with the advantages of firm suture and high healing rate.
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 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.
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.
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 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.
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 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.