Although many surgical or non-operative therapies have been developed to treat Achilles tendon injuries, the prognosis of which is often unsatisfactory. Recently, biologic approaches using ...multipotent stem cells like tendon-derived stem cells (TDSCs) pose a possible treatment option. To evaluate whether the Leucine rich repeat containing 32 (Lrrc32) affects the tenogenic differentiation of TDSCs and thus promotes Achilles tendon healing. TDSCs were infected with the recombinant Lrrc32-overexpressing lentivirus (LV-Lrrc32) and then locally injected into the injured site of rat. Four weeks after surgery, the Achilles tendon tissue (~0.5 cm) around the injured area was harvested for analysis. Pathological results showed that Lrrc32-overexpressing TDSCs significantly improved the morphological changes of the injured tendons. Specifically, the increased collagen-I expression and hydroxyproline content in extracellular matrix, and more orderly arrangement of the regenerated collagen fibers were observed in the Lrrc32 overexpression group. Moreover, 4 weeks after injection of Lrrc32-overexpressing TDSCs, the expression of tenocyte-related genes such as tenomodulin (Tnmd), scleraxis (Scx) and decorin (Dcn) were upregulated in the area of the healing tendon. These findings indicated that Lrrc32 promoted the tenogenic differentiation of TDSCs in vivo. Additionally, Lrrc32 overexpression also increased the expression of TGF-β1 and p-SMAD2/3, suggesting that the beneficial effects of Lrrc32 on tendon repair might be associated with the expression of TGF-β1 and p-SMAD2/3. Our findings collectively revealed that Lrrc32-overexpressed TDSCs promoted tendon healing more effectively than TDSCs alone.
Purpose To evaluate posterior stability and proprioception after arthroscopic posterior cruciate ligament reconstruction with autograft, hybrid graft, and γ-irradiated allograft. Methods This ...prospective, randomized controlled trial (with 5 years' follow-up) included 90 patients who underwent posterior cruciate ligament reconstruction with autograft (gracilis and semitendinosus tendons), hybrid graft (γ-irradiated tibialis anterior tendon allograft and semitendinosus tendon autograft), or γ-irradiated allograft (tibialis anterior tendons). All the γ-irradiated allografts (tibialis anterior tendons) received an irradiation dose of 2.5 Mrad before distribution. Patients in this study had undergone a preoperative magnetic resonance imaging scan and physical examination. Patients were excluded from the study if they had a concomitant injury to other knee ligaments, previous surgery on the injured knee, or articular cartilage lesions greater than Outerbridge grade II. Clinical and proprioceptive evaluation results were collected preoperatively and at 3, 6, 12, 24, 36, and 60 months after surgery. Results The autograft, allograft, and hybrid graft groups were followed up for 5.5 ± 0.2 months (range, 5 to 6 years), 5.7 ± 0.3 months (range, 5 to 6 years), and 5.6 ± 0.5 months (range, 5 to 6 years), respectively. No statistically significant differences were found among the 3 groups regarding preoperative demographic factors ( P > .05). The differences in physical examination findings and subjective evaluations among the 3 groups were not significant ( P > .05). However, a significant difference was detected in instrumented anteroposterior measurements, with more laxity shown in the γ-irradiated allograft group than in the other 2 groups ( P = .006). Conclusions The differences in proprioceptive and functional outcomes among the 3 groups were not significant. In contrast, a significant difference was detected in instrumented anteroposterior measurements, which showed more laxity in the γ-irradiated allograft group than in the other 2 groups. However, this may not be clinically significant. Level of Evidence Level II, prospective comparative study.
Synchronous grouting is the key factor causing segment floating during the construction of shield tunnel, especially the grout ratio and the control of the grouting pressure. In this paper, the ratio ...of grout material was optimized through multiple groups of physical and mechanical tests. The results showed that 0.3% content of water reducing agent in grout could improve the ability of water resistance significantly. 2.9% content of bentonite could reduce bleeding rate of grout and grout setting time and improve the fluidity in the meantime. Then, the distribution law of grout along the segment ring in the filling stage was studied based on a typical underwater tunnel in China. The results showed that the theoretical calculation of grouting pressure was between 0.15 MPa and 0.18 MPa, which were in good agreement with the measured data. The grouting pressure distribution is affected by four parts including the lateral earth pressure, foundation reaction, grout shear stress, and gravity.
Abstract
Background
Many studies have shown that hypoplasia of knee bone morphology is related to the morphological features of the discoid lateral meniscus (DLM). However, few studies have focused ...on hypoplasia of tibial eminence morphology in juvenile patients with complete DLM. The purpose of this study was to determine the relationship between tibial eminence morphology characteristics and complete DLM in juvenile patients.
Methods
The DLM group comprised 34 juvenile patients with complete DLM, and the control group comprised 34 juvenile individuals, each with a normal lateral meniscus based on magnetic resonance imaging (MRI) findings. All parameters, including tibial width (TW), tibial eminence width (TEW), the height of the lateral tibial spine (HLTS), the height of the medial tibial spine (HMTS), lateral slope angle of the lateral tibial eminence (LSALTE), lateral slope angle of the medial tibial eminence (LSAMTE), tibial eminence width ratio (TEWR), height of the lateral tibial spine ratio (HLTSR), and the height of the medial tibial spine ratio (HMTSR), were recorded using coronal MR images. Statistical analyses were used to determine the differences between the two groups and whether differences were significant.
Results
The TEW and TEWR were significantly greater (
P
< 0.05), and LSALTE and LSAMTE were significantly smaller (
P
< 0.05) in patients in the DLM group than in participants in the control group. Receiver operating characteristic (ROC) analysis revealed that a larger TEW, above 13.4 mm, was associated with complete DLM, with a sensitivity of 77.0% and specificity of 88.2%, and a larger TEWR, above 19.7%, was associated with complete DLM, with a sensitivity of 76.5% and specificity of 91.2%.
Conclusions
MR imaging can be used to diagnose tibial eminence hypoplasia in juvenile patients with complete DLM. Additionally, TEW and TEWR could help clinicians screen for complete DLM in juvenile patients.
Purpose The purpose of this study was to evaluate whether posterior cruciate ligament reconstruction with the double-bundle (DB) technique improved stability of the knee compared with the ...single-bundle (SB) technique. Methods This prospective study included 50 patients who were randomized to undergo posterior cruciate ligament reconstruction by use of tibialis anterior grafts with either the SB technique (25 patients) or DB technique (25 patients). The group assignment was concealed before allocation with the use of sealed envelopes. Posterior stability was evaluated with the KT-1000 arthrometer (MEDmetric, San Diego, CA), and clinical outcomes were assessed with the Lysholm score, Tegner activity score, and International Knee Documentation Committee score (both objective and subjective). Results There were 22 patients in the SB group and 24 patients in the DB group with a minimum follow-up period of 2 years. No differences were found between the 2 groups regarding patient demographic data and the duration from injury to operation ( P > .05). The Lysholm score was 88.0 ± 4.2 (range, 83 to 93) in the SB group and 89.8 ± 3.8 (range, 86 to 95) in the DB group, and there was no significant difference between the 2 groups ( P = .447). The Tegner activity score improved significantly to 6.2 ± 0.9 (range, 5 to 8) in the SB group and 6.8 ± 1.2 (range, 5 to 9) in the DB group. The side-to-side difference in posterior translation decreased to 4.1 ± 1.3 mm (range, 5.5 to 2.5 mm) in the SB group and 2.2 ± 1.3 mm (range, 4.5 to 2.0 mm) in the DB group, and there was a significant difference between the 2 groups ( P < .05). According to the International Knee Documentation Committee (both objective and subjective), the DB group had a better grade distribution ( P < .05) and had a statistically higher grade (71.6 ± 6.7; range, 63 to 80) than the SB group (65.5 ± 7.8; range, 56 to 75) ( P < .05). Conclusions Although both techniques resulted in similar patient satisfaction as measured by outcome assessment, the DB procedure significantly improved knee stability. Level of Evidence Level II, lesser-quality randomized controlled trial.
Interleukin-17 (IL-17), a pleiotropic cytokine, plays a significant role in the inflammatory diseases. By a pilot study with small population, IL-17 polymorphisms (IL-17A rs2275913 and IL-17F ...rs763780) showed a more potential risk factor in knee osteoarthritis (OA) in our recruited subjects. In the current study, the association between IL-17A rs2275913 and IL-17F rs763780and the risk of OA in a Chinese population is studied.
The IL-17A rs2275913 and IL-17F rs763780 polymorphisms were determined in 594 knee OA cases and 576 healthy controls, using polymerase chain reaction-restriction fragment length polymorphism assay. The relationship between genotype distribution and disease risk, as well as OA severity was analyzed by Chi-square test and multivariate logistic regression.
The experimental results indicated that the polymorphism in IL-17 gene rs2275913 site were related to knee OA risk after the adjustment of BMI, sex, age, smoking and drinking status (AA vs. GG: odds ratio (OR), 1.411; 95% confidence interval (CI), 1.021-1.950; P = 0.040; A allele vs. G allele: OR, 1.192; P = 0.037; 95% CI, 1.012-1.404;). Similarly, subjects who are bearing the rs763780 variant genotypes (TC and CC) and C allele also had a higher susceptibility to knee OA compared with those who are bearing the TT genotype (TC vs. TT, OR: 1.312; P = 0.039; 95% CI: 1.017-1.692; CC vs. TT, OR: 2.812, P = 0.006, 95% CI: 1.338-5.909; C allele Vs. T allele, OR:1.413, P = 0.002, 95% CI:1.141-1.751). In the meantime, one high-risk haplotypes, AC (OR was 7.22, P < 0.01) was found. Both two polymorphisms do not correlated with OA severity based on Kellgren-Lawrence (K&L) scales. Finally, serum IL-17 levels of knee OA patients were greatly higher than those of controls (P = 0.001).
With the limited size sample, our study shows that IL-17 gene polymorphisms possibly related to the high-risk knee OA occurrence.
Many studies have shown that distal femoral sagittal morphological characteristics have a clear relationship with knee joint kinematics. The aim of this study was to determine the relationship ...between distal femoral sagittal morphological characteristics and noncontact anterior cruciate ligament (ACL) injury.
A retrospective case-control study of 148 patients was conducted. Two age- and sex-matched cohorts (each n = 74) were analysed: a noncontact ACL injury group and a control group. Several characteristics were compared between the two groups, including the lateral femoral posterior radius (LFPR), medial femoral posterior radius (MFPR), lateral height of the distal femur (LH), medial height of the distal femur (MH), lateral femoral anteroposterior diameter (LFAP), medial femoral anteroposterior diameter (MFAP), lateral femoral posterior radius ratio (LFPRR), and medial femoral posterior radius ratio (MFPRR). Receiver operating characteristic (ROC) analysis was used to evaluate the significance of the LFPRR and MFPRR in predicting ACL injury.
Compared with patients in the control group, patients in the ACL injury group had an increased LFPR, MFPR, MFAP, LFPRR, and MFPRR. ROC analysis revealed that an increased LFPRR above 31.7% was associated with noncontact ACL injury, with a sensitivity of 78.4% and a specificity of 58.1%; additionally. an increased MFPRR above 33.4% was associated with noncontact ACL injury, with a sensitivity of 58.1% and a specificity of 70.3%.
This study showed that increased LFPRR and increased MFPRR are risk factors for developing noncontact ACL injury. These data could thus help identify individuals susceptible to ACL injuries.
Abstract
Background
Although many studies have shown that high tibial osteotomy is appropriate for active patients, there are limited multifactorial studies on patients’ sport activity level after ...HTO in general population.
Methods
158 patients who underwent HTO for knee osteoarthritis between January 2016 and December 2019 are included, with a 36-month follow-up. Information was collected from X-rays and questionnaire. The independent variables were age, sex, breadwinner (provide more than 50% income), sport activity level when the knee was pain-free before and after surgery, concomitant meniscal treatment history, Lysholm knee score, desire level for returning to sports. The 158 cases are divided into three groups according to their sports participation before and after operation, Chi-square tests and ANOVA analysis were adopted to identify the effect of these variables on sport activity level after HTO, and factors with statistical differences and clinical relevancies, or provided by previous research were assessed with the ordinal logistic regression analysis.
Results
According to sport activity level analysis, 28(17.7%) patients were categorized into the sport level-reduced group, 97(61.4%) patients into the sport level-unchanged group, and 33(20.9%) patients into the sport level-improved group. Upon ordinal logistic regression analysis, postoperative MA%, age, BMI, and preoperative Lysholm knee score were statistically significant.
Conclusions
Higher postoperative MA%, younger age, lower BMI, and lower Lysholm score are associate with improvement on activity level after HTO. This finding provides valuable references in operation option and rehabilitation planning.
Heilongjiang Province, the largest commercial grain base in China, experiences significant challenges due to the environmental effects on its soil. The freezing and thawing cycle in this region leads ...to the transport of water and heat, as well as the exchange and transfer of energy. Consequently, this exacerbates the flooding disaster in spring and severely hampers farming activities such as plowing and sowing. To gain a better understanding of the freezing and thawing mechanisms of farmland soil in cold regions and prevent spring flooding disasters, this study focuses on Heilongjiang Province as a representative area in northeast China. The research specifically investigates the frozen and thawed soil of farmland, using a large-scale low-temperature laboratory to simulate both artificial and natural climate conditions in the cold zone. By employing the similarity principle of geotechnical model testing, the study aims to efficiently simulate the engineering prototypes and replicate the process of large-span and long-time low temperatures. The investigation primarily focuses on the evolution laws of key parameters, such as the temperature field and moisture field of farmland soil during the freeze–thaw cycle. The findings demonstrate that the cooling process of soil can be categorized into three stages: rapid cooling, slow cooling, and freezing stabilization. As the soil depth increases, the variability of the soil temperature gradually diminishes. During the melting stage, the soil’s water content exhibits a gradual increase as the temperature rises. The range of water content variation during thawing at depths of 30 cm, 40 cm, 50 cm, and 80 cm is 0.12% to 0.52%, 0.47% to 1.08%, 0.46% to 1.96%, and 0.8% to 3.23%, respectively. To analyze the hydrothermal coupling process of farmland soil during the freeze–thaw cycle, a theoretical model of hydrothermal coupling was developed based on principles of mass conservation, energy conservation, Darcy’s law of unsaturated soil water flow, and heat conduction theory. Mathematical transformations were applied after defining the relative degree of saturation and solid–liquid ratio as field functions with respect to the relative degree of saturation and temperature. The simulated temperature and moisture fields align well with the measured data, indicating that the water–heat coupling model established in this study holds significant theoretical and practical value for accurately predicting soil temperature and moisture content during the spring sowing period, as well as for efficiently and effectively utilizing frozen soil resources in cold regions.
Abstract
Background
The surgical technique for treatment of tibial avulsion fractures of the posterior cruciate ligament (PCL) remains challenging due to the deep-located lesion and the complexity of ...the anatomy. The purpose of this study was to report preliminary results of an arthroscopic technique in patients with the “hinged” type PCL tibial avulsion fractures.
Methods
Twenty-eight patients with the displaced “hinged” fractures with elevation of the posterior aspect of the bony fragment were arthroscopically treated. The bony fragment was reducted and fixed with the sutures passing through only one single tibial tunnel. The clinical outcomes were assessed by Lysholm score, Tegner activity score, and the side-to-side differences of KT-1000 measurement. The reduction and union of the fracture were assessed by radiography of the knee.
Results
Patients were followed up for a mean of 19 (12 to 24) months. There were no surgery-related complications, and all patients regained normal range of motion of the knees at the last follow-up. The Lysholm score significantly increased from preoperative 14.78 ± 8.23 to postoperative 96.96 ± 3.62 (
P
= 0.000). The Tegner score was 6.78 ± 1.35 pre-injury and 6.48 ± 1.20 at the last follow-up with no statistical difference (
P
= 0.688). The KT-1000 side-to-side differences significantly decreased from 8.26(SD 1.86; 6 to 12) pre-operatively to 0.91 (SD 0.85; 0 to 3) (
P
= 0.000). X-rays showed that satisfactory reduction and solid union was achieved in all patients.
Conclusion
The arthroscopic suture fixation through single-tibial tunnel technique yielded good clinical and radiographic outcome for treatment of displaced “hinged” type of PCL avulsion fractures.
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