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 Anterior cruciate l igament (ACL) is an important forward stable structure of knees, when its function impaired, the normal mechanical environment of joint will be destroyed. Now, to explore the effect of ACL rupture on the posterior horn of lateral meniscus by measuring biomechanics. Methods Ten specimens of knee joints (5 left and 5 right sides asymmetrically) were donated voluntarily from 10 normal fresh adult male cadavers, aged 26-35 years with anaverage of 31.4 years. The straining of lateral meniscus posterior horn in 10 knee joint specimens before and after resection of ACL were tested when the knee joints loaded from 0 to 200 N at a velocity of 0.5 mm per second at 0, 30, 60, and 90° of flexion and recorded at the moment when the load was 200 N, the ratio of straining before and after resection of ACL were connted. All the specimens were anatomied and observed in general so as to find injuries such as deformation and tearing in lateral meniscus after test. Results The straining of lateral meniscus posterior horn were as follows: intact ACL group, (—11.70 ± 0.95) με at 0° flexion, (—14.10 ± 1.95) με at 30° flexion, (—20.10 ± 1.20) με at 60° flexion, and (—26.50 ± 1.58) με at 90° flexion; ACL rupture group, (—6.20 ± 1.55) με at 0° flexion, (—26.30 ± 1.89) με at 30° flexion, (—37.70 ± 1.64) με at 60° flexion, and (—46.20 ± 2.78) με at 90° flexion. There were significant differences between intact ACL group and ACL rupture group (P lt; 0.05). The straining ratio of the posterior horn of lateral meniscus rupture ACL to intact ACL were 0.53 ± 0.12, 1.90 ± 0.31, 1.88 ± 0.15, and 1.75 ± 0.16 at 0, 30, 60, and 90° of flexion. The lateral meniscus were intact in general and no injuries such as deformation and tearingwere found. Conclusion ACL has a significant biomechanical effect on posterior horn of lateral meniscus. Consequently, the posterior horn of lateral meniscus is overloaded with ACL rupture at 30, 60, and 90° of flexion, and thereby, it will have the high risk of tear.
Objective To investigate the effectiveness of meniscal allograft in treatment of discoid meniscus tear. Methods Between May 2005 and September 2009, 7 cases of discoid meniscus tear were treated with meniscal allograft. There were 2 males and 5 females with an average age of 22.6 years (range, 18-33 years). The locations were the left knee in 5cases and the right knee in 2 cases. The causes were sport trauma in 4 cases, impact injury in 2 cases, and no apparent reason in 1 case. Of them, 7 cases had joint tenderness gap, 2 cases had positive results in floating patella test, 7 cases had positive results in McMurray test, and 6 cases had positive results in squatting test. The range of knee motion was 0-60°. The disease duration ranged from 3 months to 17 years (median, 26 months). Results The number of the pins was 9-13 (mean, 11). The operative time ranged from 1.5 to 2.7 hours (mean, 1.7 hours). The postoperative fever time ranged from 31 to 57 hours (mean, 46.4 hours). Incisions healed by first intention in 6 cases; infection occurred in 1 case after operation and was cured after 18 days of local irrigation with antibiotic sal ine. Seven patients were followed up 21.6 months on average (range, 12-53 months). The range of knee motion was 0-125°. All patients had the negative results of floating patella test, McMurray test, and squatting test. MRI showed that there was a good heal ing between the transplanted meniscus and the surrounding synovium. The Japanese Orthopaedic Association (JOA) score was 80.71 ± 4.82 at 6 months after operation, showing significant difference (t=10.11, P=0.00) when compared with the score (41.71 ± 8.07) before operation. Conclusion Meniscal allograft in treatment of discoid meniscus tear is a rel iable and effective method, which can ease knee pain.
【Abstract】 Objective To compare the short-term effects of arthroscopic partial meniscectomy in treating medial versuslateral meniscus injuries. Methods From January 2003 to January 2006, 207 patients with meniscus injury(without intraarticularligament injury) underwent arthroscopic partial meniscectomy. The medial meniscus injury group included 115 cases, 50males and 65 females; aged 14 to 78 years(mean 46.9 years); 66 left knees and 49 right knees. Twenty-six cases had injury histories,the delayed time from injury to surgery ranged from 6 d to 6 months (mean 2.1 months). The lateral meniscus injury group included92 cases, 18 males and 74 females; aged 16 to 62 years (mean 41.1 years); 57 left knees and 35 right knees. Twenty-four caseshad injury histories, the delayed time from injury to surgery ranged from 9 d to 6 months (mean 1.9 months). Lysholm score systemwas applied and the scors of pre- and post-operation and were compared between two groups. Results The period of followupranged from 12 to 45 months (mean 31.5 months). In medial meniscus injury group and lateral meniscus injury roup, theLysholm score increased from 61.3±16.9 and 57.4±17.6 preoperation to 95.0±7.9 and 93.3±7.4 postoperation respectively. Therewas statistically significant difference between preoperation and postoperation (P lt; 0.01), and there was no statistically significantdifference between two groups（P gt; 0.05）. The excellent and good rates for function of knee joint were 97.39% (excellent in 107cases, good in 5 cases and fair in 3 cases) in medial meniscus injury group and 100%(excellent in 80 cases and good in 12 cases)in lateral meniscus injury group. Conclusion Arthroscopic partial meniscectomy is a safe and effective treatment for meniscusinjury, there is no diference in short-term effects in treating medial versus lateral meniscus injuries.
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.
ObjectiveTo explore the relationship between anterior cruciate ligament (ACL) reconstruction failure and medial meniscus injury and decide whether medial meniscus injury could be the judgment index for ACL reconstruction failure without trauma history. MethodsBetween March 2011 and December 2015, 117 patients underwent ACL reconstruction, and the clinical data were analyzed retrospectively. All patients had no trauma history after ACL resconstruction. MRI examination showed medial meniscus injury in 56 cases (observation group) and no medial meniscus injury in 61 cases (control group). There was no significant difference in gender, age, side, reconstructive surgery, and follow-up time between 2 groups (P>0.05). The KT-2000 arthrometer was used to measure the difference value of tibial anterior displacement between two knees in 30° knee flexion. Then wether the ACL reconsruction failure was judged according to the evaluation criteria proposed by Rijke et al. ResultsIn observation group, the difference value of tibial anterior displacement was <3 mm in 7 patients, 3-5 mm in 11 patients, and >5 mm in 38 patients. In control group, the difference value of tibial anterior displacement was <3 mm in 31 patients, 3-5 mm in 18 patients, and >5 mm in 12 patients. The ACL reconstruction failure rate of observation group (67.9%) was significantly higher than that of control group (19.7%) (χ2=27.700, P=0.000). ConclusionAfter ACL reconstruction, medial meniscus injury occurs under no trauma history circumstances, indicating ACL reconstruction failure.
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 compare the short-term effectiveness of suture hook suture via double posteromedial approaches and Fast-Fix total internal suture in treatment of Ramp lesions. Methods A clinical data of 56 patients with anterior cruciate ligament rupture combined with Ramp lesions, who met the selection criteria and admitted between December 2021 and February 2023, was retrospectively analyzed. The Ramp lesions were sutured using suture hook via double posteromedial approaches under arthroscopy in 28 cases (group A) and treated with Fast-Fix total internal suture under arthroscopy in 28 cases (group B). There was no significant difference in age, gender, cause of injury, type of injury, time from injury to operation, side of injury, body mass index, and preoperative Lysholm score, visual analogue scale (VAS) score, and Tegner score between the two groups (P>0.05). The patients were followed up regularly after operation, and the clinical and imaging healing of the Ramp lesion was evaluated according to the Barrett clinical healing standard and the MRI evaluation standard. Lysholm score, VAS score, and Tegner score were used to evaluate the function and pain degree of knee joint, and the results were compared with those before operation. ResultsThe incisions of the two groups healed by first intention. All patients were followed up 12-18 months (mean, 14.9 months). Postoperative McMurray tests were negative in both groups. The clinical healing rates of group A and group B were 71.4% (20/28) and 64.3% (18/28) at 6 months after operation, and 92.9% (26/28) and 82.1% (23/28) at 12 months after operation, respectively. The differences between the two groups was not significant (χ2=0.327, P=0.567; χ2=0.469, P=0.225). There was no significant difference in Lysholm score, VAS score, and Tegner score between the two groups at each time point after operation (P>0.05). The postoperative scores in the two groups significantly improved when compared with those before operation, and the scores at 12 months after operation further improved when compared with those at 6 months after operation, showing significant differences between the different time points in the two groups (P<0.05). At last follow-up, MRI examination of the knee joint showed that there were 26 (92.9%), 2 (7.1%), and 0 (0) cases of complete healing, partial healing, and nonunion in the Ramp lesion of group A, and 25 (89.3%), 1 (3.6%), and 2 (7.1%) cases in group B, respectively. There was no significant difference between the two groups (Z=−0.530, P=0.596). ConclusionSuture hook suture via double posteromedial approaches and Fast-Fix total internal suture under arthroscopy are safe and reliable in the treatment of Ramp lesion, and the knee joint function significantly improves after operation.
Objective To summarize and analyze the research progress of scaffold materials used in tissue engineered meniscus. Methods The classification and bionics design of scaffold materials were summarized by consulting domestic and foreign literature related to the research of tissue engineered meniscus in recent years. Results Tissue engineered meniscus scaffolds can be roughly classified into synthetic polymers, hydrogels, extracellular matrix components, and tissue derived materials. These different materials have different characteristics, so the use of a single material has its unique disadvantages, and the use of a variety of materials composite scaffolds can learn from each other, which is a hot research area at present. In addition to material selection, material processing methods are also the focus of research. At the same time, according to the morphological structure and mechanical characteristics of the meniscus, the bionic design of tissue engineered meniscus scaffolds has great potential. Conclusion At present, there are many kinds of scaffold materials for tissue engineered meniscus. However, there is no material that can completely simulate the natural meniscus, and further research of scaffold materials is still needed.