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 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 summarize the clinical features, surgical methods, and prognosis of bucket-handle meniscal tears (BHMTs), and provide guidance for clinical treatment. Methods The clinical data of 91 BHMTs patients (91 knees), who met the selection criteria and were admitted between January 2015 and January 2021, was retrospectively analyzed. There were 68 males and 23 females. Age ranged from 16 to 58 years with an average of 34.4 years. The injury was caused by sports in 68 cases, traffic accident in 15 cases, and falls or sprains in 8 cases. There were 49 cases of left knee injury and 42 cases of right knee injury. The time from the onset of symptoms to the admission ranged from 1 day to 13 months (median, 18 days), including >1 month in 35 cases and ≤1 month in 56 cases. Medial BHMTs occurred in 52 cases and lateral BHMTs in 39 cases. There were 36 cases with ACL rupture and 12 cases with discoid meniscus. The knee extension was limited more than 10° in 55 cases. According to the condition of meniscus injury, the meniscus suture with Inside-out combined with All-inside techniques (54 cases) or meniscoplasty (37 cases) under arthroscopy were selected. ACL reconstruction was performed in all patients with ACL rupture with autogenous hamstring tendon. Postoperative complications were observed. International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score were used to evaluate knee function, and clinical failure was recorded. Results Two patients developed intermuscular venous thrombosis, which improved after oral anticoagulant therapy. No vascular injury, postoperative infection, joint stiffness, or other complications occurred in all patients. All patients were followed up 24-95 months, with a median of 64 months. A total of 12 cases (13.19%) failed the operation and were re-operated or given oral anti-inflammatory analgesics and rehabilitation therapy. At last follow-up, IKDC score and Lysholm score of 91 patients significantly increased when compared with those before operation (P<0.05), while Tegner score significantly decreased (P<0.05). The above indexes of patients treated with meniscus suture and meniscoplasty were also significantly different from those before operation (P<0.05). ConclusionBHMTs occurs mostly in young men and is one of the important reasons for the limitation of knee extension after trauma. Arthroscopic meniscus suture and meniscoplasty can obtain good effectiveness according to individual conditions of patients. But the latter can better preserve the shape and function of meniscus, and theoretically can obtain better long-term outcomes, which needs to be confirmed by further research with larger sample size.
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 measure and analyze the relationships among the posterior tibial slope (PTS), meniscal slope (MS), and meniscus posterior horn thickness (MPHT) of the medial and lateral tibial plateau in healthy people and patients with anteromedial osteoarthritis (AMOA) in Heilongjiang province, so as to provide reference basis for appropriate tibial osteotomy and prosthesis placement angles in knee joint surgeries. Methods A retrospective collection of imaging data from knee joint MRI examinations conducted prior to AMOA for various reasons was performed. A total of 103 healthy individuals (healthy group) and 30 AMOA patients (AMOA group) were included. There was no significant difference in the gender composition ratio, side, and body mass index between the two groups (P>0.05); however, the comparison of ages between the two groups showed a significant difference (P<0.05). The collected DICOM format image data was imported into the RadiAnt DICOM Viewer software and measured the medial PTS (MPTS), lateral PTS (LPTS), medial MS (MMS), lateral MS (LMS), medial MPHT (MMPHT), and lateral MPHT (LMPHT) with standard methods. The differences of the above indexes between the two groups and between different genders and sides in the two groups were compared, and Pearson correlation analysis was carried out. At the same time, the measured data of healthy group were compared with the relevant literature reported in the past. Results Compared to the healthy group, the AMOA group exhibited significantly smaller MPTS and LPTS, as well as significantly greater MMPHT and LMPHT, with significant differences (P<0.05). However, there was no significant difference in the MMS and LMS between the two groups (P>0.05). The differences in various indicators between genders and sides within the two groups were not significant (P>0.05). The correlation analysis and regression curves indicated that both MPTS and LPTS in the two groups were positively correlated with their respective ipsilateral MS and MPHT (P<0.05); as PTS increased, the rate of increase in MS and MPHT tend to plateau. Compared to previous related studies, the MPTS and LPTS measured in healthy group were comparable to those of the Turkish population, exhibiting smaller values than those reported in other studies, while MMS and LMS were relatively larger, and MMPHT and LMPHT were smaller. ConclusionIn healthy people and AMOA patients in Heilongjiang province, PTS has great individual differences, but there is no significant individual difference in MS. MPHT can play a certain role in retroversion compensation, and its thickness increase may be used as one of the indicators to predict the progression of AMOA. The above factors should be taken into account when UKA is performed, and the posterior tilt angle of tibial osteotomy should be set reasonably after preoperative examination and evaluation.
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.
【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.
