Normal Knee Research Articles

Anterior cruciate ligament (ACL) injuries: A review on the newest reconstruction techniques.

The anterior cruciate ligament (ACL) is considered very important for normal knee function, the disruption of which may result in malfunction, meniscal lesions, and the early onset of joint degeneration. The aim of this comprehensive review was to investigate the different techniques used in the reconstruction of damaged ACL. Current methods in reconstruction of ACL include different types of autograft and allograft to replace native ligaments. The ideal graft for reconstruction of ACL is one which is biomechanically similar to the native ligament, is easily harvested, has least harvest site morbidity, and gets well incorporated with the bone. Cross-fixing of hamstrings has been created for ACL reconstruction in the hopes of improving potential problems related to the interference screw and button fixation technique. Previous clinical results indicated that double-bundle ACL reconstruction is equivalent or even superior to single-bundle ACL reconstruction in regaining anterior and rotational stability.

Post operative correlation of femoral tibial components with knee alignment using roentgenographic index in patients undergoing total knee arthroplasty in a tertiary referral centre

Total knee arthroplasty is the leading surgical treatment for advanced osteoarthritis of the knee. Despite its efficiency, approximately twenty percent of the cases are dissatisfied with the outcome. Mal positioning of components results in loosening, which has long-term consequences. As a result, proper sizing and placement are important for optimal functional and long-term outcomes. Achieving limb alignment, good soft tissue balance and pain relief are the primary goals of the surgeon upon completion of total knee replacement (TKA). The aim of this study was to determine the accuracy of placement of femoral and tibial components post-operatively in relation to knee alignment using a roentgenographic index. This is a prospective study conducted in a tertiary care referral hospital, we included a total of fifty cases who underwent total knee arthroplasty from the year 2019 to 2020. Post-operative radiographic parameters were measured using digital software and compared using roentgenographic indexes as described by Lotke et al. Out of the fifty Total Knee Arthroplasty cases, twenty-eight knees had perfectly positioned tibial and femoral prosthesis, fifteen cases had good position of both the components. Tibial component alignment angle (β = 90°) in relation to mechanical axis in coronal plane was seventy six percent; fourteen percent of the cases were in native knee varus. Femoral component alignment angle (α) with acceptable anatomical valgus (0-7°) were more than eighty percent of the cases. 85.5 was the mean roentgenographic index which was strongly correlatable with other similar studies. With good clinical acumen and using conventional alignment system, near to normal knee alignment in total knee arthroplasty is achievable.

Early outcomes of ultra-congruent insert in cruciate-retaining total knee arthroplasty: A prospective study

Introduction: The exponents of cruciate-retaining (CR) total knee arthroplasty (TKA) assert that the retention of posterior cruciate ligament (PCL) preserves more normal knee kinematics, femoral rollback on the tibia during flexion, greater stabilization of the prosthesis, and improved position sense as compared to PCL resection TKA. However, one has to shift to the posterior stabilized (PS) femoral component with box and accompanying cam postpolyethylene, especially in cases where PCL is too attenuated to be functional or too tight predisposing to accelerated polyethylene wear. To minimize both the cam mechanism polyethylene wear and the bone sacrifice due to the intercondylar box cut, the ultra-congruent (UC) inserts have been developed that are characterized by a high anterior wall and a deep-dished plate, promising good stability without cam mechanism. Materials and Methods: We did a prospective study to clinically evaluate the short-term results of the patients who underwent TKA using cemented posterior CR implants and UC inserts. PCL was required to be released either partially or completely in all the study patients. Thirty patients were evaluated preoperatively and postoperatively after 12 months with the new Knee Society Knee Scoring System (2011) and the findings were statistically analyzed. Results: There was a statistically significant postoperative improvement in flexion (from mean of 87.69° to 111.53°, P = 0.000), objective knee indicators (33.53 ± 8.51–70.84 ± 4.91, P = 0.000), patient satisfaction scores (7.48 ± 2.12–21.53 ± 4.26, P = 0.000), and the functional activities score (32.53 ± 5.12–69.02 ± 6.36, P = 0.000). We did not note any disadvantage of CR TKA with UC insert and no patient underwent an early revision for instability. Conclusion: Using UC insert in CR TKA is a reliable procedure that has decreased the dependence on the PS designs.

Isokinetic exercises in quadriceps strength and endurance recovery after anterior cruciate ligament reconstruction

Background/Aim: Muscle strength and endurance recovery of the quadriceps after anterior cruciate ligament reconstruction is necessary for normal knee function. In addition to the use of the isokinetic dynamometer for diagnostic purposes, its possible therapeutic effect is also important, ie targeted correction of the measured muscle deficit. This work was aimed to examine the level of quadriceps strength and endurance recovery 6 months after the anterior cruciate ligament reconstruction in patients who performed isokinetic training and to determine whether it is a superior therapeutic intervention compared to isodynamic training. Methods: A total of 70 patients of both sexes were monitored in a prospective clinical study. Three months postoperatively, all patients had quadriceps torque measured to body weight on an isokinetic dynamometer at angular speeds of 60 and 180 °/s. Patients were divided into two groups according to the type of applied rehabilitation protocol. Group A patients (n = 35) underwent a rehabilitation program 5 times a week using an individual kinesitherapy program (isometric and isotonic exercises for quadriceps and hamstrings) and neuromuscular electrostimulation of the quadriceps. In addition patients from group B (n = 35) were included in targeted isokinetic exercises for the quadriceps. Control isokinetic testing was performed 6 months after surgery. The comparison of the effect of the applied therapeutic procedures in groups A and B was performed with the Student t-test (p < 0.05). Results: An average age of patients was 27.29 ± 5.94 years. In patients in group B, statistically significantly higher values of the peak torque to body weight were measured at angular velocities of 60 and 180 °/s for the quadriceps of the operated knee 6 months after reconstruction of the anterior cruciate ligament with hamstring tendons (p < 0.05). Conclusion: Isokinetic training achieved significantly better quadriceps strength and endurance in patients 6 months after anterior cruciate ligament reconstruction with hamstring tendons compared to dynamic exercises.

An Imaging Measurement Study of Normal Knee Parameters in Southeast China.

Imaging measurement of distal femur and proximal tibia has been the hot point in the research of total knee arthroplasty and prosthesis development, which is an important treatment for patients with advanced knee joint disease. This study retrospectively investigated the digital imaging measurement of normal knee parameters in southeast China and evaluated their clinical value. From February 2010 to May 2014, and in accordance with the inclusion criteria, a total of 677 knees (334 female knees and 343 male knees) were categorized into 3 age groups. Clinical and digital imaging data, including the distal Femoral Condyle Diameter (FCD), Tibial Plateau Diameter (TPD), the distance between the medial tibial plateau and fibular head (DPF), tibiofemoral valgus angle, distal femoral valgus angle, Proximal Tibia (PT) varus angle and the angle from femoral condyle to tibial perpendicular (FT), were measured by using AutoCAD 10.0 software. All measured variables were statistically analyzed by SPSS statistical software (version 18.0). Data are presented as the mean ± standard deviation. The normal female and male femoral condyle diameter was (7.69 ± 0.46) cm and (8.68 ± 0.55) cm, while the normal female and male tibial plateau diameter was (7.66 ± 0.46) cm and (8.60 ± 0.55) cm, respectively. The normal female and male DPF was (0.76 ± 0.36) cm and (0.79 ± 0.36) cm. For females and males, the tibiofemoral valgus angle and distal femoral valgus angle were (3.89 ± 2.20) ° and (3.29 ± 2.12) °, (9.03 ± 2.18) ° and (8.25 ± 2.20) °. As the two methods to measure tibial plateau varus angle, PT angle of normal female and male was (4.29 ± 1.86) ° and (4.84 ± 2.23) °, while the normal female and male FT angle was (5.34 ± 1.95) ° and (5.52 ± 2.07) °. Based on the data obtained, we found significant differences between the two genders in terms of the femoral condyle diameter and tibial plateau diameter in all age groups (P < 0.01). The DPF parameter showed an obvious difference between the young group and the middle-aged group (P < 0.05), and no significant difference was observed between the sides and genders (P > 0.05). The distal femoral valgus angle showed statistical differences between genders in the left side of the young group and middle-aged group (P < 0.05), while angle PT and FT showed no significant difference (P > 0.05). A large number of knee measurements was obtained, and a local knee database was developed in this study. Imaging measurement prior to total knee arthroplasty is clinically important for increasing the accuracy and long-term efficacy of total knee arthroplasty. These data can also provide useful information for knee surgery and sports medicine as well as prosthesis development.

Radiographic Measurements of Normal Knee Joint Space in Adults

Introduction: The knee joint is the space between the femoral and tibial condyles. The tibiofemoral articulations are separated by articular cartilages and menisci; with little contributions from cruciate ligaments. These are collectively seen on a radiograph as a radiolucent area between the bony tibial and femoral condyles. This study was conducted to measure the normal knee joint space in patients referred for X-Ray to the Department of Radiology of a tertiary care hospital.&#x0D; Methods: This descriptive cross-sectional study was performed from 1st January to 1st April 2021 in the Department of Radiology and Imaging, Tribhuvan University Teaching Hospital (TUTH). A total of 157 patients were involved. The radiographic joint space width in the knee joint was measured in both medial and lateral compartments of bilateral knees in correlation with age and gender.&#x0D; Results: The mean right medial, left medial, right lateral, and left lateral spaces for females were 0.25±0.08 cm, 0.23±0.09 cm, 0.49±0.10 cm, and 0.49±0.29 cm respectively. Similarly, the mean right medial left medial, right lateral, and left lateral spaces for males were 0.26±0.07 cm, 0.10±0.09 cm, 0.18±0.09 cm, and 0.17±0.08 cm respectively. There was a strong positive correlation between both right and left joint spaces about age.&#x0D; Conclusion: The radiographic reference values for the joint space width were obtained, showing a positive correlation with age and no significant gender variations in bilateral knees.

Tibiofemoral Relationship 3 Weeks After Anatomic Triple-Bundle Anterior Cruciate Ligament Reconstruction With 10 N of Initial Tension Is Closer to Normal Knee Versus That With 20 N of Initial Tension

PurposeThis study aimed to clarify the effect of initial graft tension on the ensuing tibiofemoral relationship and on 2-year clinical outcomes after anatomic triple-bundle anterior cruciate ligament (ACL) reconstruction. MethodsA total of 31 patients with primary unilateral ACL rupture (mean age, 25.1 years) were enrolled. Anatomic triple-bundle ACL reconstruction was performed using semitendinosus tendon autografts, and patients were grouped according to the total initial tension at graft fixation: 20 N for 16 patients between January 2012 and December 2012 and 10 N for 15 patients between January 2013 and December 2013. Three-dimensional computed tomography scans were performed preoperatively and at 3 weeks and 6 months postoperatively. The side-to-side difference of the 3-dimensional tibial position relative to the femur was compared at each time point. The side-to-side difference in anterior laxity was sequentially compared preoperatively, immediately after surgery, and at 6 months and 2 years postoperatively. Clinical outcomes at 2 years were likewise compared. ResultsOne patient in each group was excluded because of secondary ACL injury. At 3 weeks postoperatively, 2.5 ± 1.3 and 1.0 ± 1.3 mm of posterior tibial displacement and 3.8° ± 2.4° and 2.0° ± 1.7° of external rotation were observed in the 20- and 10-N initial tension groups, respectively, with significant differences (P = .006 and .033). At 6 months postoperatively, anterior displacement was 0.1/0.1 mm and external rotation was 0.8°/0.4° in both groups, without any significant differences. The 2-year clinical outcomes were satisfactory, including mean side-to-side difference in anterior knee laxity of 0.5 mm in both groups. ConclusionThe tibiofemoral relationship 3 weeks after anatomic triple-bundle ACL reconstruction with 10 N of initial tension is less constrained than that with 20 N. Six-month tibiofemoral relationship and 2-year clinical outcomes are satisfactory in both groups. Level of EvidenceIII, retrospective comparative trial

Epigenetic modifications of tumor necrosis factor-alpha in joint cartilage tissue from osteoarthritis patients - CONSORT.

Background:Osteoarthritis (OA) remains one of the most common osteopathy for centuries, which can be attributed to multiple risk factors including mechanical and biochemical ones. More and more studies verified that inflammatory cytokines play important roles in the progression of OA, such as tumor necrosis factor-alpha (TNF-α). In this study, we aimed to investigate the relationship between epigenetic manifestations of TNF-? and the pathogenesis of OA.Methods:Totally, 37 OA patients’ cartilage was collected through the knee joint and 13 samples of articular cartilage as healthy control was collected through traumatic amputation. Real-time PCR, Western blot and ELISA analysis were performed to observe the expression of target genes and proteins in collected samples.Results:Compared with the healthy control group, TNF-? was over-expressing in cartilage which was collected from OA patients. DNA hypomethylation, histone hyperacetylation and histone methylation were observed in the TNF-? promoter in OA compared with normal patients, and we also studied series of enzymes associated with epigenetics. The results showed that by increasing DNA methylation and decreasing histone acetylation in the TNF-? promoter, and TNF-? over-expression in OA cartilage was suppressed, histone methylation has no significant correlation with OA.Conclusion:In conclusion, the changes of epigenetic status regulate TNF-α expression in the cells, which are pivotal to the OA disease process. These results may give us a better understanding of OA and may provide new therapeutic options.

Post-Traumatic Osteoarthritis Assessment in Emerging and Advanced Pre-Clinical Meniscus Repair Strategies: A Review.

Surgical repair of meniscus injury is intended to help alleviate pain, prevent further exacerbation of the injury, restore normal knee function, and inhibit the accelerated development of post-traumatic osteoarthritis (PTOA). Meniscus injuries that are treated poorly or left untreated are reported to significantly increase the risk of PTOA in patients. Current surgical approaches for the treatment of meniscus injuries do not eliminate the risk of accelerated PTOA development. Through recent efforts by scientists to develop innovative and more effective meniscus repair strategies, the use of biologics, allografts, and scaffolds have come into the forefront in pre-clinical investigations. However, gauging the extent to which these (and other) approaches inhibit the development of PTOA in the knee joint is often overlooked, yet an important consideration for determining the overall efficacy of potential treatments. In this review, we catalog recent advancements in pre-clinical therapies for meniscus injuries and discuss the assessment methodologies that are used for gauging the success of these treatments based on their effect on PTOA severity. Methodologies include histopathological evaluation of cartilage, radiographic evaluation of the knee, analysis of knee function, and quantification of OA predictive biomarkers. Lastly, we analyze the prevalence of these methodologies using a systemic PubMed® search for original scientific journal articles published in the last 3-years. We indexed 37 meniscus repair/replacement studies conducted in live animal models. Overall, our findings show that approximately 75% of these studies have performed at least one assessment for PTOA following meniscus injury repair. Out of this, 84% studies have reported an improvement in PTOA resulting from treatment.

Adaptive Vibrarthographic Signal Denoising via Ant Colony Optimization Using Dynamic Denoising Filter Parameters

This study proposes an ant colony optimization (ACO) denoising method with dynamic filter parameters. The proposed method is developed based on ensemble empirical mode decomposition (EEMD), and aims to improve the quality of vibrarthographic (VAG) signals. It mixes the original VAG signals with different white noise amplitudes, and adopts a hybrid technology that combines EEMD with a Savitzky-Golay (SG) filter containing the dynamic parameters optimized by ACO. The results show that the proposed method provides a higher peak signal-to-noise ratio (PSNR) and a smaller root-mean-square difference than the regular methods. The SNR improvement for the VAG signals of normal knees can reach 13 dB while maintaining the original signal structure, and the SNR improvement for the VAG signals of abnormal knees can reach 20 dB. The method proposed in this study can improve the quality of nonstationary VAG signals.

Biomechanical Comparison of Kinematic and Mechanical Knee Alignment Techniques in a Computer Simulation Medial Pivot Total Knee Arthroplasty Model.

Several concepts may be used to restore normal knee kinematics after total knee arthroplasty. One is a kinematically aligned (KA) technique, which restores the native joint line and limb alignment, and the other is the use of a medial pivot knee (MPK) design, with a ball and socket joint in the medial compartment. This study aimed to compare motions, contact forces, and contact stress between mechanically aligned (MA) and KA (medial tilt 3° [KA3] and 5° [KA5]) models in MPK. An MPK design was virtually implanted with MA, KA3, and KA5 in a validated musculoskeletal computer model of a healthy knee, and the simulation of motion and contact forces was implemented. Anteroposterior (AP) positions, mediolateral positions, external rotation angles of the femoral component relative to the tibial insert, and tibiofemoral contact forces were evaluated at different knee flexion angles. Contact stresses on the tibial insert were calculated using finite element analysis. The AP position at the medial compartment was consistent for all models. From 0° to 120°, the femoral component in KA models showed larger posterior movement at the lateral compartment (0.3, 6.8, and 17.7 mm in MA, KA3, and KA5 models, respectively) and larger external rotation (4.2°, 12.0°, and 16.8° in the MA, KA3, and KA5 models, respectively) relative to the tibial component. Concerning the mediolateral position of the femoral component, the KA5 model was positioned more medially. The contact forces at the lateral compartment of all models were larger than those at the medial compartment at >60° of knee flexion. The peak contact stresses on the tibiofemoral joint at 90° and 120° of knee flexion were higher in the KA models. However, the peak contact stresses of the KA models at every flexion angle were <20 MPa. The KA technique in MPK can successfully achieve near-normal knee kinematics; however, there may be a concern for higher contact stresses on the tibial insert.

Twelve Weeks of a Staged Balance and Strength Training Program Improves Muscle Strength, Proprioception, and Clinical Function in Patients with Isolated Posterior Cruciate Ligament Injuries.

Ligament reconstruction is indicated in patients with an isolated posterior cruciate ligament (PCL) injury who fail conservative treatment. To eliminate the need for PCL reconstruction, an ideal rehabilitation program is important for patients with an isolated PCL injury. The purpose of this study was to investigate the improvement in functional outcome, proprioception, and muscle strength after a Both Sides Up (BOSU) ball was used in a balance combined with strength training program in patients with an isolated PCL injury. Ten patients with isolated PCL injuries were recruited to receive a 12 week training program as a study group. In the control group (post-PCL reconstruction group), ten subjects who had undergone isolated PCL reconstruction for more than 2 years were enrolled without current rehabilitation. The Lysholm score, IKDC score, proprioception (active and passive), and isokinetic muscle strength tests at 60°/s, 120°/s, and 240°/s, were used before and after training on the injured and normal knees in the study group, and in the post-PCL reconstruction group. The results were analyzed with a paired t-test to compare the change between pre-training, post-training, and the normal leg in the study group, and with an independent t-test for comparisons between the study and post-PCL reconstruction groups. Both the Lysholm and IKDC scores were significantly improved (p < 0.01) after training, and no difference was observed compared to the post-PCL reconstruction group. The active and passive proprioception was improved post-training compared to pre-training, with no difference to that in the post-PCL reconstruction group. Isokinetic knee quadriceps muscle strength was significantly greater post-training than pre-training in PCL injured knees at 60°/s, 120°/s, and 240°/s, and in hamstring muscle strength at 60°/s and 120°/s. Muscle strength in the post-training injured knee group showed no significant difference compared to that in the post-training normal leg and the post-PCL reconstruction group. The post-training improvement of muscle strength was higher in the PCL injured leg compared to the normal leg and there was no difference between the dominant and non-dominant injured leg in the study group. After 12 weeks of BOSU balance with strength training in patients with an isolated PCL injury, the functional outcome, proprioception, and isokinetic muscle strength were significantly improved, and comparable to the contralateral normal leg and the post-PCL reconstruction group. We suggest that programs combining BOSU balance and strength training should be introduced in patients with a PCL injury to promote positive clinical results.

Three-dimensional morphometric differences of resected distal femurs and proximal tibias in osteoarthritic and normal knees

BackgroundThere is a paucity of data concerning the morphological differences of resected distal femurs and proximal tibias in osteoarthritic (OA) and normal knees. The objective of this study was to determine whether morphometric differences in the surfaces of resected distal femurs and proximal tibias exist between OA and normal knees in a Chinese population.MethodsNinety-four OA knees and ninety-five normal knees were evaluated in Chinese individuals. Computed tomography was used to measure the femoral mediolateral (fML), medial anteroposterior (fMAP), lateral anteroposterior (fLAP), medial condylar width (fMCW), lateral condylar width (fLCW), medial posterior condylar curvature radii (fMCR), lateral posterior condyle curvature radii (fLCR), fML/fMAP aspect ratio, tibial mediolateral (tML), middle anteroposterior (tAP), medial anteroposterior (tMAP), and lateral anteroposterior (tLAP) tML/tMAP aspect ratio to determine the morphologic differences between OA and normal knees.ResultsThe average fMCW and tMAP dimensions of OA knees were larger than those of normal knees in both male and female (p <0.05). The fMAP/fML aspect ratio and tMAP/tML aspect ratio were also significantly different in both sexs (p <0.05). OA knees have an oval-shaped distal femur with a wider ML length and more spherical-shaped proximal tibiae with relatively narrow ML dimensions.ConclusionsThe study revealed the morphological differences in fMCW, tMAP, fMAP/fML and tMAP/tML between OA and normal knees in both males and females. These findings may provide guidelines that can be used to design better knee implants that are more size-matched for OA knees.

Study on the relationship between the expression of S100A12, CaSR, and IL-7R in the synovium of knee osteoarthritis and angiogenesis.

To analyze the relationship between the expression of calcium binding protein (S100A12), calcium sensitive receptor (CaSR), and interleukin-7 receptor (IL-7R) in the synovium of knee osteoarthritis (KOA) and angiogenesis. The clinical data of 92 patients with KOA admitted to Sichuan Provincial People's Hospital from February 2019 to May 2020 were collected (KOA group, Kellgren-Lawrence staging: 23 cases of grade 2, 49 cases of grade 3, and 20 cases of grade 4). In addition, 87 cases of patients with normal knee cartilage that were not involved during the same period of treatment in this hospital were selected. The expressions of S100A12, CaSR, IL-7R, and microvascular density (MVD) were compared among different populations, and the correlation between S100A12, CaSR, IL-7R, and MVD, and its diagnostic value for KOA were analyzed. The values of S100A12, CaSR, IL-7R, and MVD in the KOA group were significantly higher than those in the control group (P<0.05); the values of S100A12, CaSR, and IL-7R in grade 4 patients were significantly higher than those in grade 2 and 3 patients (P<0.05); S100A12, CaSR, IL-7R, and MVD were all positively correlated, and the difference was statistically significant (P<0.05). According to the receiver operating characteristic (ROC) curve, the area under the curve (AUC) of S100A12, CaSR, and IL-7R for KOA diagnosis was 0.982, 0.929, and 0.899, respectively. The Youden index was 0.630, 0.835, 0.739, respectively. The expression levels of S100A12, CaSR, and IL-7R in the synovium of KOA are significantly up-regulated, and they are closely related to angiogenesis.

Influence of different sized nanoparticles combined with ultrasound on the optical properties of in vitro knee joint and knee osteoarthritis cartilage tissue was studied by OCT and diffuse reflectance spectroscopy

The penetration and accumulation of zinc oxide nanoparticles (ZnO NPs) with different sizes in human normal knee joint (NKJ) tissue and knee osteoarthritis (OA) tissue were studied by continuous optical coherence tomography and diffuse reflectance (DR) spectroscopy in this paper, and the effects of ZnO NPs of two sizes (30 nm and 90 nm) and ultrasound (US) on the optical properties of human NKJ and OA tissue were evaluated. The results show that the average attenuation coefficients of NKJ tissue decrease by 14.90%, 26.91%, 33.52% and 37.01%, and the DR spectra increases by 8.444%, 12.901%, 18.219% and 26.125%, respectively, after being treated with 90 nm ZnO NPs, 90 nm ZnO NPs/US, 30 nm ZnO NPs and 30 nm ZnO NPs/US. The average attenuation coefficients of OA tissue are reduced by 32.14%, 49.51%, 57.85% and 72.30%, and the DR spectra increase by 17.426%, 23.116%, 25.218% and 29.326%, respectively, after being treated with 90 nm ZnO NPs, 90 nm ZnO NPs/US, 30 nm ZnO NPs and 30 nm ZnO NPs/US. It is concluded that the optical properties of NKJ and OA tissues are greatly influenced by ZnO NPs and US. Nanoparticles have a greater impact on OA tissue than on NKJ tissue.

Changes in Muscle Strategies During Landing Task in Subjects With and Without Knee Genu Varum

Introduction: Onset and offset activation of lower limb and trunk muscles may change the knee with genu varum during landing. These motor control strategies can be different from those in healthy subjects and contribute to more injuries in lower extremities. This study aimed to compare the delay time of the onset activity of the abdominal and lower limb muscles in the specific landing task. Materials and Methods: Ten females with genu varum deformity and ten females with normal knee participated in this case-control study. Genu varum deformity was measured by a camera capturing goniometer. The subjects were informed to land by preferred lower limb from a table (30 cm high) on a force plate. Vertical Ground Reaction Force (VGRF) was measured to clarify the onset of the landing task. Surface Electromyography (sEMG) of transverse abdominal/int. oblique (TA/IO), Vastus Medialis (VM), Vastus Lateralis (VL), Lateral Gastrocnemius (LG), and medial gastrocnemius (MG) muscles were recorded during landing. The difference between the onset activity of the above muscles and onset of VGRF was calculated as delay times and compared between muscles and between two groups. Also, the offset of activities and the intensity of muscle activation (normalized RMS) were compared between the two groups. Results: Lower limb and trunk muscles showed significantly different onset of activities in the genu varum group (P&lt;0.05), whereas there was no significant difference in the onset of muscle activities in the healthy group. Results indicated significant differences between two groups in TA/IO, LG, and MG muscles and the genu varum group had longer delay time for motor control strategy (especially ankle strategy) in the landing task. Offset time of all muscles in the genu varum and healthy subjects had a significant difference between muscles, especially in gastrocnemius muscles (P&lt;0.05). Also, there were significant changes between the two groups in LG and MG muscles (P&lt;0.05). Normalized muscle activities (nRMS) generally indicated an increase in muscle activation of genu varum subjects (TA/IO, LG, MG) compared with the normal subjects (P&lt;0.05). Conclusion: Motor control strategies in landing task is different in the genu varum group due to changes in biomechanics and properties of the knee joint. This variation may be due to changes in proprioception afferent pathways around the knee joint. An increase in muscle activation, delay, and offset time of muscle activities in these subjects, indicated that an increase in the degree of freedom may change motor control strategies. Internal anticipation and postural adjustment of the landing task in these subjects need more motor unit recruitment (an increase in nRMS). This deformity in the knee joint might affect some activities and possibly cause knee changes such as osteoarthritis.

Immune cell profiles in synovial fluid after anterior cruciate ligament and meniscus injuries

BackgroundAnterior cruciate ligament (ACL) and meniscus tears are common knee injuries. Despite the high rate of post-traumatic osteoarthritis (PTOA) following these injuries, the contributing factors remain unclear. In this study, we characterized the immune cell profiles of normal and injured joints at the time of ACL and meniscal surgeries.MethodsTwenty-nine patients (14 meniscus-injured and 15 ACL-injured) undergoing ACL and/or meniscus surgery but with a normal contralateral knee were recruited. During surgery, synovial fluid was aspirated from both normal and injured knees. Synovial fluid cells were pelleted, washed, and stained with an antibody cocktail consisting of fluorescent antibodies for cell surface proteins. Analysis of immune cells in the synovial fluid was performed by polychromatic flow cytometry. A broad spectrum immune cell panel was used in the first 10 subjects. Based on these results, a T cell-specific panel was used in the subsequent 19 subjects.ResultsUsing the broad spectrum immune cell panel, we detected significantly more total viable cells and CD3 T cells in the injured compared to the paired normal knees. In addition, there were significantly more injured knees with T cells above a 500-cell threshold. Within the injured knees, CD4 and CD8 T cells were able to be differentiated into subsets. The frequency of total CD4 T cells was significantly different among injury types, but no statistical differences were detected among CD4 and CD8 T cell subsets by injury type.ConclusionsOur findings provide foundational data showing that ACL and meniscus injuries induce an immune cell-rich microenvironment that consists primarily of T cells with multiple T helper phenotypes. Future studies investigating the relationship between immune cells and joint degeneration may provide an enhanced understanding of the pathophysiology of PTOA following joint injury.

Apprehension of future injury is not related to running behaviour in runners who have had knee surgery

Introduction: Apprehension or fear of reinjury after knee surgery is one of the most cited reasons for not returning to preinjury sport and physical activity participation, despite normal postoperative knee function. Not returning to sport and reduced physical activity participation are associated with poor quality of life, increased body mass, and depression. The influence of apprehension of a future injury on running behaviour remains unknown. The aim of our study was to explore whether apprehension of a future injury relates to running behaviour in runners who have had knee surgery.

Synovial Fluid Cytokines, Chemokines and MMP Levels in Osteoarthritis Patients with Knee Pain Display a Profile Similar to Many Rheumatoid Arthritis Patients.

Background: There are currently no effective disease-modifying drugs to prevent cartilage loss in osteoarthritis and synovial fluid is a potentially valuable source of biomarkers to understand the pathogenesis of different types of arthritis and identify drug responsiveness. The aim of this study was to compare the differences between SF cytokines and other proteins in patients with OA (n = 21) to those with RA (n = 27) and normal knees (n = 3). Methods: SF was obtained using ultrasound (US) guidance and an external pneumatic compression device. RA patients were categorized as active (n = 20) or controlled (n = 7) based upon SF white blood cell counts (> or <300 cells/mm3). Samples were cryopreserved and analyzed by multiplex fluorescent bead assays (Luminex). Between-group differences of 16 separate biomarker proteins were identified using ANOVA on log10-transformed concentrations with p values adjusted for multiple testing. Results: Only six biomarkers were significantly higher in SF from active RA compared to OA—TNF-α, IL-1-β IL-7, MMP-1, MMP-2, and MMP-3. Only MMP-8 levels in RA patients correlated with SF WBC counts (p < 0.0001). Among OA patients, simultaneous SF IL-4, IL-6, IL-8, and IL-15 levels were higher than serum levels, whereas MMP-8, MMP-9, and IL-18 levels were higher in serum (p < 0.05). Conclusion: These results support the growing evidence that OA patients have a pro-inflammatory/catabolic SF environment. SF biomarker analysis using multiplex testing and US guidance may distinguish OA phenotypes and identify treatment options based upon targeted inflammatory pathways similar to patients with RA.

Percutaneous hemiepiphysiodesis using transphyseal screws for adolescent tibia vara.

Hemiepiphysiodesis around the knee is becoming the mainstay procedure in adolescents for a wide range of aetiological deformities, when considering adolescent tibia vara (ATV), the published series have variable results. The purpose of this study was to review our experience with the percutaneous transphyseal screw (PETS) in these patients followed until bone maturity. We analysed the charts from 13 patients (20 knees) that underwent lateral tibial hemiepiphysiodesis using PETS. The radiographs were accessed before surgery, at implant removal, when occurred, and at the final follow-up. The clinical evaluation noted if there were complaints regarding pain or range of motion, and the radiographic assessment included: the femorotibial angle, the mechanical axis zone, the anatomic lateral distal femoral angle, and medial mechanical proximal tibial angle. There was one overcorrection, and after the screw removal (14 knees), rebound was observed in two knees modifying the result from excellent to good in all three knees. No bone bars and no implant breakage were observed. At the last appointment, all patients had normal knee range of motion, and two patients had unilateral alignment complaints, one of whom referred to occasional pain. Overall, the surgery was excellent in 12 knees (60%), good in six knees (30%), and poor in two knees (10%). This technique is indicated to be well tolerated and effective for treating ATV. When a complete correction cannot be obtained, in our opinion, it is advantageous to at least stabilise the deformity and postpone osteotomies until after skeletal maturity. Level of Evidence: Level IV - Case Series, Therapeutic Study.