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 knee arthroscopy with wire anchor nailing composite double pulley technique in the treatment of anterior cruciate ligament (ACL) tibial avulsion fracture involving the anterior root of the lateral meniscus (LM). Methods Clinical data of 35 patients with ACL tibial avulsion fracture involving the anterior root of the LM admitted between January 2019 and September 2023 and met the selection criteria were retrospectively analysed. There were 20 males and 15 females; ages ranged from 10 to 57 years, with a mean of 29 years. The time from injury to surgery ranged from 3 to 20 days, with a mean of 9.6 days. Meyers-McKeever classification included 5 cases of type Ⅱ, 12 cases of type Ⅲ, and 18 cases of type Ⅳ. Preoperative anterior knee instability Lachman test and anterior drawer test were positive. The anterior root of the LM as well as the avulsion fracture block were fixed using suture anchor nails compounded with double pulley technique under arthroscopy. Postoperative X-ray films were performed to assess fracture healing; knee stability was assessed using the anterior drawer test and Lachman test, anterior laxity of the knee was measured by KT-2000, and knee function was assessed using the Lysholm score and the International Knee Documentation Committee (IKDC) score; at last follow-up, the recovery of the meniscus was assessed using the McMurry test and knee hyperextension test. Results All the patients were successfully operated, the operation time ranged from 56 to 78 minutes,with an average of 67.6 minutes, and there was no nerve or blood vessel injury during operation. Thirty-five cases were followed up 12-18 months with an average of 15.1 months. During the follow-up, there was no infection, knee stiffness, loosening of internal fixation, fracture displacement, or re-fracture. The fractures all healed, with a clinical healing time of 8-15 weeks, averaging 10.9 weeks. At last follow-up, 4 patients had weakly positive anterior drawer test and Lachman test, and the rest were negative; McMurry test and knee hyperextension test were negative; no patient complained of knee extension pain or straightening obstacles, and all the patients resumed their normal life or sports and labour; 16 patients with unclosed epiphyses did not have any epiphyseal injuries or growth disorders. Lysholm score, IKDC score, and KT-2000 anterior knee laxity at last follow-up significantly improved when compared with preoperative ones (P<0.05). Conclusion The treatment of ACL tibial avulsion fracture involving the anterior root of the LM with suture anchor composite double pulley technique can effectively fix the anterior root of the LM while fixing the avulsion fracture block, and better restore the function and stability of the knee joint.
ObjectiveTo investigate the effect of different saline irrigation volume under arthroscopy on early postoperative pain and swelling of the knee.MethodsThe clinical data of 539 patients with meniscus injury treated by arthroscopic menisci reformation who met the selection criteria between July 2016 and February 2020 were retrospectively analyzed. They were divided into three groups according to the continuous saline irrigation volume during the operation: 176 patients in the non-irrigation group (group A), 183 patients in the 1 liter-irrigation group (group B), and 180 patients in the 3 liters-irrigation group (group C). There was no significant difference in gender, age, cause of injury, sides of injury, body mass index, disease duration, smoking history, and classification of meniscus injury among 3 groups (P>0.05). At 6, 12, 24, 48, and 72 hours after operation, the patient’s pain level was evaluated by the visual analogue scale (VAS) score, and the knee swelling situation was evaluated by the swelling ratings (the difference between both sides in circumference of the 2 cm upper patella of the knee). Knee skin temperature (the difference of the skin temperature between both sides) and the C-reactive protein (CRP) level in serum were measured at the 1st and 3rd days after operation. Range of motion of the knee was measured at the 1st, 3rd, and 5th days after operation.ResultsAll incisions healed by first intention without any complication after operation. The VAS scores of each group showed a slow increase trend after operation, and gradually decreased to less than the VAS score of 6 hours at 48 hours after operation. There was no significant difference in VAS scores among the 3 groups at each time point after operation (P>0.05). The swelling ratings of the knee in each group showed a gradually decrease trend after operation. There was no significant difference in the swelling ratings of the knee among the 3 groups at each time point after operation (P>0.05). The skin temperature of the knee in each group decreased at the 3rd day after operation than the 1st day, and there was no significant difference in the skin temperature of the knee among the 3 groups at each time point after operation (P>0.05). There was no significant difference in CRP level within the group and among the 3 groups at each time point after operation (P>0.05). Range of motion of the knee in each group increased gradually at the 1st, 3rd, and 5th days after operation, and there was no significant difference among the 3 groups at each time point after operation (P>0.05).ConclusionThe different continuous saline irrigation volume would not affect the early postoperative pain, swelling, and inflammation of the knee during the arthroscopic menisci plasty.
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.
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 evaluate the clinical diagnostic value of knee MRI at 90° flexed position for Ramp lesions of medial meniscus. Methods A total of 228 patients with knee pain as the main complaint who were admitted between September 2021 and September 2023 was selected as the research subjects, of which 51 patients met the selection criteria and were enrolled in the study. There were 31 males and 20 females with an average age of 38.6 years (range, 15-67 years). Body mass index was 17.2-28.7 kg/m2 (mean, 23.9 kg/m2). There were 25 cases of left knee and 36 cases of right knee. The time from injury to admission was 0.1-14.3 weeks (mean, 2.1 weeks). Preoperative knee MRI at fully extended position (knee extension position) and 90° flexed position (knee flexion position) were performed to determine the presence of irregular signs at the posterior edge of the medial meniscus, and PHMM fluid high signal [i.e. complete fluid filling between the posterior horn of the medial meniscus (PHMM) and the capsule margin]. Findings obtained under arthroscopy served as the “gold standard” to analyze the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of MRI at knee extension and flexion positions for the two specific signs of Ramp lesion.Results Twenty-one patients (41.2%) were diagnosed with Ramp lesions by using arthroscopy, including 1 case of Thaunat type Ⅰ, 2 cases of type Ⅱ, 6 cases of type Ⅲ, 7 cases of type Ⅳ, and 5 cases of type Ⅴ. The positive rates of irregular signs at the posterior edge of the medial meniscus on MRI at knee extension and flexion positions were significantly different from the diagnosis of Ramp injury under arthroscopy (P<0.05). The sensitivity, specificity, accuracy, PPV, and NPV of MRI in the diagnosis of irregular signs were 76.1%, 60.0%, 66.7%, 57.1%, and 78.3% respectively at knee extension position, and 85.7%, 73.3%, 78.4%, 69.2%, and 88.0% respectively at knee flexion position. The positive rates of PHMM fluid high signal on MRI at knee extension and flexion positions were significantly different from the diagnosis of Ramp injury under arthroscopy (P<0.05). The sensitivity, specificity, accuracy, PPV, and NPV of MRI in diagnosing PHMM fluid high signal were 38.1%, 100%, 74.5%, 100%, and 69.8% respectively at knee extension position, and 85.7%, 100%, 94.1%, 100%, and 90.9% respectively at knee flexion position. ConclusionKnee MRI at 90° flexed position improves the diagnostic performance of the detection of medial meniscal Ramp lesions compared with MRI at fully extended position.
Objective To investigate the construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal (3D) printing technology and evaluate its biocompatibility. Methods The fresh pig meniscus was decellularized by improved physicochemical method to obtain decellularized meniscus matrix homogenate. Gross observation, HE staining, and DAPI staining were used to observe the decellularization effect. Toluidine blue staining, safranin O staining, and sirius red staining were used to evaluate the retention of mucopolysaccharide and collagen. Then, the decellularized meniscus matrix bioink was prepared, and the new tissue engineered meniscus scaffold was prepared by low temperature deposition 3D printing technology. Scanning electron microscopy was used to observe the microstructure. After co-culture with adipose-derived stem cells, the cell compatibility of the scaffolds was observed by cell counting kit 8 (CCK-8), and the cell activity and morphology were observed by dead/live cell staining and cytoskeleton staining. The inflammatory cell infiltration and degradation of the scaffolds were evaluated by subcutaneous experiment in rats. Results The decellularized meniscus matrix homogenate appeared as a transparent gel. DAPI and histological staining showed that the immunogenic nucleic acids were effectively removed and the active components of mucopolysaccharide and collagen were remained. The new tissue engineered meniscus scaffolds was constructed by low temperature deposition 3D printing technology and it had macroporous-microporous microstructures under scanning electron microscopy. CCK-8 test showed that the scaffolds had good cell compatibility. Dead/live cell staining showed that the scaffold could effectively maintain cell viability (>90%). Cytoskeleton staining showed that the scaffolds were benefit for cell adhesion and spreading. After 1 week of subcutaneous implantation of the scaffolds in rats, there was a mild inflammatory response, but no significant inflammatory response was observed after 3 weeks, and the scaffolds gradually degraded. Conclusion The novel tissue engineered meniscus scaffold constructed by low temperature deposition 3D printing technology has a graded macroporous-microporous microstructure and good cytocompatibility, which is conducive to cell adhesion and growth, laying the foundation for the in vivo research of tissue engineered meniscus scaffolds in the next step.
ObjectiveTo discuss the MRI diagnostic criteria, classification and lesion characteristics of medial discoid meniscus of the knee. MethodsWe retrospectively analyzed the clinical data of all patients who accepted MRI examination of knee from November 2009 to March 2015.Twenty-six of them (28 knees) with medial discoid meniscus were screened out.We measured and analyzed in all cases the ratio of the width of meniscus to that of tibial plateau on coronal slice, and the thickest thickness of the meniscus posterior horn on sagittal slice.All cases were divided into complete and incomplete type according to MRI findings, and then we compared the lesion rate of the two types of medial discoid meniscus. ResultsTwenty-eight cases were divided into complete type (n=16) and incomplete type (n=12);there were 17 cases of medial discoid meniscal tears, with a lesion rate of 60.7%.The ratio of the width of meniscus to that of tibial plateau on coronal slice was 0.29±0.06, and the thickest thickness of the meniscus posterior horn was (5.31±0.92) mm.The lesion rate of complete type was 81.2%, and 33.3% of the incomplete type.The lesion rate of the complete type was higher than that of the incomplete type, and the difference was statistically significant (P < 0.05). ConclusionsThree MRI diagnostic criteria for medial discoid meniscus are 3 or more than 3 consecutive layers discoid meniscus "tie-like" change in sagittal slice, the ratio of the width of meniscus to that of tibial plateau≥0.20, and the thickest thickness of the meniscus posterior horn≥4.40 mm.Medial discoid meniscuses are divided into complete and incomplete type; the lesion rate of complete type of medial discoid meniscus is higher than that of the incomplete type.
Objective To investigate the medium-term clinical outcome of encircled suture for repair of medial meniscus bucket-handle tear (BHT). Methods Between March 2011 and June 2013, 78 patients (78 knees) with medial meniscus BHT were treated with encircled suture under arthroscopy. There were 57 males and 21 females with a mean age of 28.3 years (range, 16-39 years). The causes included sports injury in 61 cases, traffic accident injury in 12 cases, and other trauma in 5 cases. Of 78 cases, 35 were acute injury and 43 were chronic injury; 65 cases had combined injury of anterior cruciate ligament rupture. International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score were 48.2±6.3, 43.6±4.7, and 2.5±0.6, respectively. Barrett’s assessment standard, MRI, and arthroscopy examination were used for assessment of meniscus healing. IKDC score, Lysholm score, and Tegner score were used for assessment of knee function. Results Primary healing of incisions were achieved in all patients, and no complications occurred. All patients were followed up 26-63 months (mean, 42.8 months). BHT recurrence was observed in 2 patients within 1 year. Clinical healing of meniscus tear was obtained in 72 cases (92.3%) according to Barrett’s assessment standard. The IKDC score, Lysholm score, and Tegner score were significantly improved to 81.5±5.1, 86.9±3.9, and 6.2±0.5 respectively (t=–14.598,P=0.000;t=–18.478,P=0.000;t=–3.362,P=0.002). MRI results showed complete healing in 56 cases, incomplete healing in 15 cases, and unhealing in 7 cases at last follow-up, with a total healing rate of 91.0% (71/78) and a complete healing rate of 71.8% (56/78). In 21 cases undergoing arthroscopy at 18-49 months after operation, complete healing and incomplete healing were observed in 17 cases and 4 cases respectively, with a total healing rate of 100% (21/21) and a complete healing rate of 81.0% (17/21). No re-tear occurred. Conclusion Encircled suture for repair of medial meniscus BHT owns the advantage of firm suturing and good blood supply which can obtain satisfactory medium-term clinical results.
Objective To summarize the current research progress on the concept, clinical presentation, diagnosis, biomechanical changes, and pathological mechanisms of the medial meniscus posterior root tear (MMPRT), and its clinical correlations with tibial rotation. MethodsThe research literature on MMPRT and its relationship with tibial rotation at home and abroad in recent years was extensively consulted and summarized. Results MMPRT is a specific and common type of medial meniscus injury of the knee joint. The occurrence of posterior medial pumping pain events following low-energy trauma in patients provides important clues for the diagnosis of this injury, with MRI being the preferred imaging modality. The biomechanical effects generated by MMPRT are similar to those caused by total removal of the medial meniscus. And this injury is usually associated with tibial rotation. MMPRT induces pathological external rotation of the tibia, which can be restored by timely medial meniscus posterior root repair. Furthermore, changes in tibial rotation are related to the healing status after medial meniscus posterior root repair. ConclusionMMPRT is closely related to tibial rotation. Understanding the biomechanics, pathological mechanisms, and clinical correlations between the two is of great significance for improving the diagnosis and treatment strategies.