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.
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 investigate the effectiveness of double-needle suture for mixed meniscus tear repair under arthroscope. Methods Between April 2006 and January 2011, 22 patients with mixed meniscus tear were treated with double-needle suture under arthroscope. There were 14 males and 8 females, aged 18-41 years (mean, 31.3 years). All injuries were caused by sports. The time between injury and admission ranged from 2 days to 4 years (median, 11 months). International Knee Documentation Committee (IKDC) score was 42.5 ± 15.2, Lysholm score was 45.5 ± 13.5, and Tegner score was 2.9 ± 1.6. Seventeen cases complicated with anterior cruciate ligament injury. Results Healing of incision by first intention was achieved in all patients. No injury of nerve and blood occurred. The patients were followed up 12-48 months with an average of 27.6 months. According to Barrett et al. standard, 19 cases (86%) got clinical healing. The IKDC, Lysholm, and Tegner scores were improved to 77.1 ± 8.9, 79.8 ± 9.9, and 6.8 ± 1.6 respectively at last follow-up, showing significant differences when compared with preoperative scores (P lt; 0.05). Conclusion Arthroscopic meniscus repair using double-needle suture can provide good effectiveness because it has high firmness.
Objective To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. Methods The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. ResultsThe results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. Conclusion The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Objective To review the research progress of meniscus repair in recent years, in order to provide help for the clinical decision-making of meniscus injury treatment. Methods The domestic and foreign literature related to meniscal repair in recent years was extensively reviewed to summarize the reasons for the prevalence of meniscal repair, surgical indications, various repair methods and long-term effectiveness, the need to deal with mechanical structural abnormalities, biological enhancement repair technology, rehabilitation treatment, and so on. Results In order to delay the occurrence of osteoarthritis, the best treatment of meniscus has undergone an important change from partial meniscectomy to meniscal repair, and the indications for meniscal repair have been expanding. The mid- and long-term effectiveness of different meniscal repair methods are ideal. During meniscus repair, the abnormality of lower limb force line and meniscus protrusion should be corrected at the same time. There are controversies about the biological enhancement technology to promote meniscus healing and rehabilitation programs, which need further study. ConclusionMeniscal repair can restore the normal mechanical conduction of lower limbs and reduce the incidence of traumatic osteoarthritis, but the poor blood supply and healing ability of meniscal tissue bring difficulties to meniscal repair. Further development of new biological enhanced repair technology and individualized rehabilitation program and verification of its effectiveness will be an important research direction.
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 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 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 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.
ObjectiveTo review the research progress on the lower limb biomechanical characteristics of patients with discoid lateral meniscus (DLM) injury after surgery. MethodsBy searching relevant domestic and international research literature on DLM, the postoperative characteristics of knee joint movement biomechanics, tibiofemoral joint stress distribution, lower extremity force line, and patellofemoral joint changes in patients with DLM injury were summarized. ResultsSurgical treatment can lead to varying degrees of changes in the lower limb biomechanical characteristics of patients with DLM injury. Specifically, the kinematic biomechanics of the knee joint can significantly improve, but there are still problems such as extension deficits in the affected knee joint. The peak stress of the tibiofemoral joint decreases with the increase of the residual meniscus volume, and the degree of change is closely related to the residual meniscus volume. Preserving a larger volume of the meniscus, especially the anterior horn volume, helps to reduce stress concentration. The lower extremity force line will deviate outward after surgery, and the more meniscus is removed during surgery, the greater the change in the lower extremity force line after surgery. There are conditions such as cartilage degeneration, position and angle changes in the patellofemoral joint after surgery. ConclusionThe changes in the lower limb biomechanical characteristics after DLM injury are closely related to the choice of surgical methods and rehabilitation programs. However, the mechanisms of biomechanical changes in multiple lower limb joints and individual differences still need to be further studied and clarified.