Onset Of Knee Osteoarthritis Research Articles

Genetic predisposition to thyrotoxicosis and onset of knee osteoarthritis.

Thyroid hormones have actions on cartilage, whereas the association between thyroid hormone related diseases and osteoarthritis (OA) are unclear. This study aims to investigate the association between thyrotoxicosis and OA. Summary-level genetic data of thyrotoxicosis were obtained from FinnGen cohorts (nCase = 10,569, nControl = 762,037). Summary-level data of OA were obtained from a large-scale genome-wide association study of UK Biobank (nCase = 40,659, nControl = 756,338). Single nucleotide polymorphisms (SNPs) robustly associated with thyrotoxicosis or OA were used as genetic instruments. A two-sample bidirectional Mendelian randomization (MR) analysis was designed to assess the effect of genetic predisposition of thyrotoxicosis on OA risk, as well as the reverse their relationship. The causal effect was estimated by Inverse-variance weighted method, with weighted median and MR-Egger as supplementary methods. Genetic predisposition of thyrotoxicosis was associated with the onset of knee OA (autoimmune hyperthyroidism: odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.03-1.07, FDR < 0.001; thyrotoxicosis: OR: 1.05, 95% CI: 1.02-1.08, FDR = 0.016; thyrotoxicosis with diffuse goitre: OR: 1.04, 95% CI: 1.02-1.07, FDR = 0.003; other and/or unspecified thyrotoxicosis: OR: 1.05, 95% CI: 1.02-1.09, FDR = 0.003), whereas thyrotoxicosis was not associated with hip OA. In reverse MR analysis, genetic predisposition to OA was not associated with thyrotoxicosis. No pleiotropy was identified in the MR analyses. Sensitivity analyses indicated the robustness of the MR estimates. This study provides MR evidence supporting causal association of thyrotoxicosis with knee OA in European population, whereas OA may have no causal effects on thyrotoxicosis.

Evidence supported by Mendelian randomization: impact on inflammatory factors in knee osteoarthritis.

Prior investigations have indicated associations between Knee Osteoarthritis (KOA) and certain inflammatory cytokines, such as the interleukin series and tumor necrosis factor-alpha (TNFα). To further elaborate on these findings, our investigation utilizes Mendelian randomization to explore the causal relationships between KOA and 91 inflammatory cytokines. This two-sample Mendelian randomization utilized genetic variations associated with KOA from a large, publicly accessible Genome-Wide Association Study (GWAS), comprising 2,227 cases and 454,121 controls of European descent. The genetic data for inflammatory cytokines were obtained from a GWAS summary involving 14,824 individuals of European ancestry. Causal relationships between exposures and outcomes were primarily investigated using the inverse variance weighted method. To enhance the robustness of the research results, other methods were combined to assist, such as weighted median, weighted model and so on. Multiple sensitivity analysis, including MR-Egger, MR-PRESSO and leave one out, was also carried out. These different analytical methods are used to enhance the validity and reliability of the final results. The results of Mendelian randomization indicated that Adenosine Deaminase (ADA), Fibroblast Growth Factor 5(FGF5), and Hepatocyte growth factor (HFG) proteins are protective factors for KOA (IVWADA: OR = 0.862, 95% CI: 0.771-0.963, p = 0.008; IVWFGF5: OR = 0.850, 95% CI: 0.764-0.946, p = 0.003; IVWHFG: OR = 0.798, 95% CI: 0.642-0.991, p = 0.042), while Tumor necrosis factor (TNFα), Colony-stimulating factor 1(CSF1), and Tumor necrosis factor ligand superfamily member 12(TWEAK) proteins are risk factors for KOA. (IVWTNFα: OR = 1.319, 95% CI: 1.067-1.631, p = 0.011; IVWCSF1: OR = 1.389, 95% CI: 1.125-1.714, p = 0.002; IVWTWEAK: OR = 1.206, 95% CI: 1.016-1.431, p = 0.032). The six proteins identified in this study demonstrate a close association with the onset of KOA, offering valuable insights for future therapeutic interventions. These findings contribute to the growing understanding of KOA at the microscopic protein level, paving the way for potential targeted therapeutic approaches.

Effect of sensor number and location on accelerometry-based vertical ground reaction force estimation during walking.

Knee osteoarthritis is a major cause of global disability and is a major cost for the healthcare system. Lower extremity loading is a determinant of knee osteoarthritis onset and progression; however, technology that assists rehabilitative clinicians in optimizing key metrics of lower extremity loading is significantly limited. The peak vertical component of the ground reaction force (vGRF) in the first 50% of stance is highly associated with biological and patient-reported outcomes linked to knee osteoarthritis symptoms. Monitoring and maintaining typical vGRF profiles may support healthy gait biomechanics and joint tissue loading to prevent the onset and progression of knee osteoarthritis. Yet, the optimal number of sensors and sensor placements for predicting accurate vGRF from accelerometry remains unknown. Our goals were to: 1) determine how many sensors and what sensor locations yielded the most accurate vGRF loading peak estimates during walking; and 2) characterize how prescribing different loading conditions affected vGRF loading peak estimates. We asked 20 young adult participants to wear 5 accelerometers on their waist, shanks, and feet and walk on a force-instrumented treadmill during control and targeted biofeedback conditions prompting 5% underloading and overloading vGRFs. We trained and tested machine learning models to estimate vGRF from the various sensor accelerometer inputs and identified which combinations were most accurate. We found that a neural network using one accelerometer at the waist yielded the most accurate loading peak vGRF estimates during walking, with average errors of 4.4% body weight. The waist-only configuration was able to distinguish between control and overloading conditions prescribed using biofeedback, matching measured vGRF outcomes. Including foot or shank acceleration signals in the model reduced accuracy, particularly for the overloading condition. Our results suggest that a system designed to monitor changes in walking vGRF or to deploy targeted biofeedback may only need a single accelerometer located at the waist for healthy participants.

Strategies for knee stabilising and pivot-shift avoidance in a step-down and cross-over task observed sub-acutely after anterior cruciate ligament reconstruction

BackgroundIndividuals with a recent anterior cruciate ligament reconstruction may demonstrate an altered movement strategy for protecting the knee and maintaining stability. Altered knee movement might lead to abnormal intra-articular load, potentially contributing to early knee osteoarthritis onset. A protective strategy may be particularly evident during active tasks that induce a pivot-shift manoeuvre, such as a step-down and cross-over task. In this study, we investigated whether knee joint mechanics and muscle activity differed between participants early (∼3 months) following reconstruction (n = 35) to uninjured controls (n = 35) during a step-down and cross-over task with a 45° change-of-direction. MethodsWe used motion capture, force plates and surface electromyography to compare time-normalised curves of sagittal and transverse-plane knee mechanics and muscle activity during the cross-over phase between groups using functional t-tests. We also compared knee mechanics between sides within the injured group and compared discrete outcomes describing the cross-over phase between groups. FindingsCompared to controls, the injured participants had greater knee flexion angle and moment, lower internal rotation moment, more preparatory foot rotation of the pivoting leg, a smaller cross-over angle, and a longer cross-over phase for both the injured and uninjured sides. The injured leg also had greater biceps femoris and vastus medialis muscle activity compared to controls and different knee mechanics than the uninjured leg. InterpretationIndividuals with anterior cruciate ligament reconstruction showed a knee-stabilising and pivot-shift avoidance strategy for both legs early in rehabilitation. These results may reflect an altered motor representation and motivate considerations early in rehabilitation.

Genomic Determinants of Knee Joint Biomechanics: An Exploration into the Molecular Basis of Locomotor Function, a Narrative Review.

In recent years, the nexus between genetics and biomechanics has garnered significant attention, elucidating the role of genomic determinants in shaping the biomechanical attributes of human joints, specifically the knee. This review seeks to provide a comprehensive exploration of the molecular basis underlying knee joint locomotor function. Leveraging advancements in genomic sequencing, we identified specific genetic markers and polymorphisms tied to key biomechanical features of the knee, such as ligament elasticity, meniscal resilience, and cartilage health. Particular attention was devoted to collagen genes like COL1A1 and COL5A1 and their influence on ligamentous strength and injury susceptibility. We further investigated the genetic underpinnings of knee osteoarthritis onset and progression, as well as the potential for personalized rehabilitation strategies tailored to an individual's genetic profile. We reviewed the impact of genetic factors on knee biomechanics and highlighted the importance of personalized orthopedic interventions. The results hold significant implications for injury prevention, treatment optimization, and the future of regenerative medicine, targeting not only knee joint health but joint health in general.

Efficacy of Modified Progressive Resistance Training on Knee Strength in Women with Early Onset of Knee Osteoarthritis

Background: The synovial joint capsule, subchondral bone, and joint cartilage are all impacted by the gradualdegenerative condition known as OA. This research work is designed to check the efficacy of modified progressiveresistance training for OA knee patients.Purpose: To compare the effectiveness of modified progressive resistance training and conventional treatment onknee strength in early onset knee OA.Materials and Methods: 370 subjects were screened for study from GNK physiotherapy clinic according toinclusion and exclusion criteria from november 2022 to june 2023. Patient’s authorization was acquired afterthe procedure was completely clarified to them. They were divided into two categories: Group A (n=185) andGroup B (n=185). The pre and post-test values measured by WOMAC questionnaire and MMT. Group A receivedconventional treatment that is strengthening and stretching exercises and Group B received modified progressiveresistance training using Thera band along with conventional treatment. Both training programs were given for 4weeks, weekly 5 daysResults: A statistically important distinction &lt;0.0001 between groups A and B was found via statistical analysis ofinformation that was quantitative.Conclusion: Modified progressive resistance training using Thera band of group A were proven to be moresuccessful than group A Traditional therapy.

Roles of low muscle strength and sarcopenic obesity on incident symptomatic knee osteoarthritis: A longitudinal cohort study.

Sarcopenia is prevalent in middle to old age. We aimed to investigate the association between muscle strength and the incident knee osteoarthritis (OA). 12,043 participants were collected from the China Health and Retirement Longitudinal Study. The effects of sarcopenic obesity (defined by obesity in combination with possible sarcopenia) on knee OA onset were calculated using Poisson regression models. Mediation analysis was fit to estimate mediating proportion of muscle strength on the association between obesity and incident knee OA. The study all enrolled 12,043 participants with 2,008 progressed to knee OA. Poisson analyses demonstrated causal association of general obesity (RR:1.23, 95% CI: 1.08 to 1.39) and abdominal obesity (RR:1.23, 95% CI: 1.11 to 1.35) with knee OA onset. For the risk of incident knee OA, participants with the highest level of normalized grip strength had a decreased risk of incident knee OA by 0.33 (RR:0.67, 95% CI: 0.60 to 0.75) times compared to the control group, and chair-rising time was associated with increased risk of incident knee OA by 0.65 (RR:1.65, 95% CI: 1.17 to 2.33) times. Sensitivity analysis identified similar results. Participants with sarcopenic obesity were about 2 times risk of incident knee OA than reference group. Normalized grip strength and chair-rising time mediated the association between obesity and incidence of knee OA. Sarcopenic obesity is correlated with an increased risk of knee OA. Muscle strength recovery may alleviate the risk of incident knee OA in middle to old age with obesity.

Exploring relationships among multi-disciplinary assessments for knee joint health in service members with traumatic unilateral lower limb loss: a two-year longitudinal investigation

Motivated by the complex and multifactorial etiologies of osteoarthritis, here we use a comprehensive approach evaluating knee joint health after unilateral lower limb loss. Thirty-eight male Service members with traumatic, unilateral lower limb loss (mean age = 38 yr) participated in a prospective, two-year longitudinal study comprehensively evaluating contralateral knee joint health (i.e., clinical imaging, gait biomechanics, physiological biomarkers, and patient-reported outcomes); seventeen subsequently returned for a two-year follow-up visit. For this subset with baseline and follow-up data, outcomes were compared between timepoints, and associations evaluated between values at baseline with two-year changes in tri-compartmental joint space. Upon follow-up, knee joint health worsened, particularly among seven Service members who presented at baseline with no joint degeneration (KL = 0) but returned with evidence of degeneration (KL ≥ 1). Joint space narrowing was associated with greater patellar tilt (r[12] = 0.71, p = 0.01), external knee adduction moment (r[13] = 0.64, p = 0.02), knee adduction moment impulse (r[13] = 0.61, p = 0.03), and CTX-1 concentration (r[11] = 0.83, p = 0.001), as well as lesser KOOSSport and VR-36General Health (r[16] = − 0.69, p = 0.01 and r[16] = − 0.69, p = 0.01, respectively). This longitudinal, multi-disciplinary investigation highlights the importance of a comprehensive approach to evaluate the fast-progressing onset of knee osteoarthritis, particularly among relatively young Service members with lower limb loss.

Can exercise interventions reduce external knee adduction moment during gait? A systematic review and meta-analysis

BackgroundAn increased external knee adduction moment has been identified as a factor contributing to the progression of medial knee osteoarthritis. Interventions that reduce knee adduction moment may help prevent knee osteoarthritis onset and progression. While exercise interventions have been commonly used to treat knee osteoarthritis, whether exercises can modulate knee adduction moment in knee osteoarthritis patients remains unknown. This systematic review and meta-analysis aimed to determine if exercise interventions are effective in reducing knee adduction moment during gait. MethodsStudy reports published through May 2023 were screened for pre-specified inclusion/exclusion criteria. Nine studies met the eligibility criteria and yielded 24 effect sizes comparing the reduction in knee adduction moment of the exercise intervention groups to the control groups. Moderator/experimental variables concerning characteristics of the exercise interventions and included subjects (e.g., sex, BMI, type of exercise, muscle group targeted, training volume, physical therapist supervision) that may contribute to variation among studies were explored through subgroup analysis and meta-regression. FindingsThe effect of exercise intervention on modulating knee adduction moment during gait was no better than control (ES = -0.004, P = 0.946). Sub-group analysis revealed that the effect sizes of studies containing only females (positive exercise effect) were significantly greater than studies containing both males and females. InterpretationExercise may not be effective in reducing knee adduction moment during gait. Clinicians aiming to decrease knee adduction moment in patients with medial knee osteoarthritis should consider alternative treatment options. Exploring the underlying mechanism(s) regarding a more positive response to exercises in females may help design more effective exercise interventions.

Fatigue-driven compliance increase and collagen unravelling in mechanically tested anterior cruciate ligament

Approximately 300,000 anterior cruciate ligament (ACL) tears occur annually in the United States, half of which lead to the onset of knee osteoarthritis within 10 years of injury. Repetitive loading is known to result in fatigue damage of both ligament and tendon in the form of collagen unravelling, which can lead to structural failure. However, the relationship between tissue’s structural, compositional, and mechanical changes are poorly understood. Herein we show that repetitive submaximal loading of cadaver knees causes an increase in co-localised induction of collagen unravelling and tissue compliance, especially in regions of greater mineralisation at the ACL femoral enthesis. Upon 100 cycles of 4× bodyweight knee loading, the ACL exhibited greater unravelled collagen in highly mineralized regions across varying levels of stiffness domains as compared to unloaded controls. A decrease in the total area of the most rigid domain, and an increase in the total area of the most compliant domain was also found. The results highlight fatigue-driven changes in both protein structure and mechanics in the more mineralized regions of the ACL enthesis, a known site of clinical ACL failure. The results provide a starting point for designing studies to limit ligament overuse injury.

Incidence density and relative rate assessment of knee osteoarthritis with respect to BMI, age and gender conducted in a tertiary care hospital in Hyderabad, India

Background: Osteoarthritis is the most common form of arthritis associated with limitation in mobility. Weight bearing joints of axial and peripheral skeleton are primarily affected. Prevalence of symptomatic knee osteoarthritis among men and women is 10% and 13%. Ageing and obesity epidemic are the leading causes for development of osteoarthritis in a given population. Methods: The study was conducted at a tertiary care hospital in Hyderabad, India. Data was gathered from orthopedic department on a daily basis during the study duration. Patients with any grade of Kellgren-Lawrence scale of knee osteoarthritis were included in the study and incidence density, relative rate, p-value were assessed. Results: During the study course, a total of 100 patients were enrolled. Overweight, obese and healthy patients contributed to 51%, 33% and 16% of incidence density with relative rate as 1.04, 0.49 and 0.19 respectively (p-value=0.042). Incidence density of patients ≥45 years and &lt;45 years was 83% and 17% with relative rate as 4.9 and 0.2 (p value&lt;0.0001). Incidence density in males and females was 34% and 66% with relative rate as 1.94 and 0.51 (p-value&lt;0.0001). The data analyzed is statistically significant. Conclusions: A direct proportionality between people exceeding normal BMI range and progression of knee osteoarthritis is observed due to strain manifested on diarthrodial joint by overweight patients. Increase in age is associated with onset of knee osteoarthritis because of age related-changes seen in cartilage and loss of chondrocytes. Women are more affected with knee osteoarthritis when compared to men due to irregularities in hormones post-menopause.

Body mass affects kinetic symmetry and inflammatory markers in adolescent knees during gait

BackgroundEarly-onset osteoarthritis has been attributed to pro-inflammatory factors and biomechanical changes in obesity. However, research has yet to explore whether knee joint moments are asymmetrical in children with obesity and could precede the onset of knee osteoarthritis. The present study compares knee moment asymmetry between adolescents with and without obesity and examines the relationship between asymmetries and inflammatory biomarkers. MethodsTwenty-eight adolescents (13–16 years) were classified as with (n = 12) or without (n = 16) obesity. Lower extremity kinetics were measured using three-dimensional motion analysis. Bilateral knee joint moments were analyzed in the sagittal, frontal, and transverse planes across stance phase. Kinetic asymmetry was calculated between the right and left sides and represented by the R2 value. Enzyme-linked immunosorbent assays analyzed serum 25-hydroxy vitamin D, interferon gamma, tumor nercrosis factor alpha, interleukin-6, and C-reactive protein levels. Parametric and non-parametric tests determined significant group differences in asymmetries and biomarkers, respectively. Spearman's correlations identified relationships between biomarkers and asymmetries with statistically significant group differences. FindingsAdolescents with obesity had greater sagittal (loading, midstance) and frontal (midstance, pre-swing) plane kinetic knee asymmetry and higher concentrations of interleukin-6 and C-reactive protein. A moderately negative correlation existed between C-reactive protein and sagittal (loading, midstance) plane asymmetry, and also between interleukin-6 and frontal (pre-swing) plane asymmetry. InterpretationInflammatory response increases with greater knee joint asymmetry, suggesting knee joint damage and altered joint loading co-exist in adolescents with obesity. Increased risk to joint health may exist in sub-phases where knee joints are improperly loaded.

Passive stiffness of the quadriceps predicts the incidence of clinical knee osteoarthritis in twelve months.

Quadriceps weakness is a known risk factor for the onset of knee osteoarthritis (OA). In addition to muscle weakness, increased passive stiffness of the quadriceps may affect knee biomechanics and hence contribute to the pathogenesis of knee OA. However, the association between quadriceps stiffness and the risk of knee OA development has not been prospectively investigated. The aim of this study was to investigate how baseline quadriceps passive stiffness predicts the incidence of clinical knee OA at the 12-month follow-up. Prospective cohort study. University laboratory. Community-dwelling adults aged 60-80 years were recruited. We excluded participants with: 1) knee pain or known arthritis; 2) knee injury; 3) knee or hip joint replacement, 4) cognitive impairment; or 5) neurological conditions. At baseline, passive stiffness of the three superficial quadriceps muscle heads (rectus femoris [RF], vastus lateralis [VL], and vastus medialis oblique [VMO]) was evaluated using shear-wave ultrasound elastography. Knee muscle (quadriceps and hamstrings) strength was tested using a Cybex dynamometer. Knee OA was defined based on clinical criteria 12 months after baseline measurements. Generalized estimating equations were used to examine the associations of quadriceps stiffness and knee muscle strength with the risk of knee OA, controlling for age, sex, Body Mass Index, comorbidities, and activity level. The analyses included 158 knees (58.2% females, age: 65.6±4.1 years). Twenty-eight knees (17.7%) were classified as having clinical OA at 12 months. Compared with the lowest stiffness tertiles, the highest stiffness tertiles of the RF (relative risk =5.31, 95% CI: 1.34-21.0), VMO (4.15, 1.04-16.6), and total superficial quadriceps (6.35, 1.48-27.3) at baseline were significantly associated with a higher risk of knee OA at the follow-up. The highest strength tertile of quadriceps has a trend of association with a lower risk of knee OA than the lowest tertile (0.18, 0.03-1.25, P=0.083). Greater passive stiffness of the quadriceps at baseline was associated with a higher risk of clinical knee OA incidence at the 12-month follow-up. Interventions for reducing the passive stiffness of the quadriceps should be included in preventative training programs for older adults.

Joint instability causes catabolic enzyme production in chondrocytes prior to synovial cells in novel non-invasive ACL ruptured mouse model

The Anterior Cruciate Ligament (ACL)-deficient model helps to clarify the mechanism of knee osteoarthritis (OA); however, the conventional ACL injury model could have included concurrent onset factors such as direct compression stress to cartilage and subchondral bone. In this study, we established a novel Non-invasive ACL-Ruptured mouse model without concurrent injuries and elucidated the relationship between OA progression and joint instability. We induced the ACL-Rupture non-invasively in twelve-week-old C57BL/6 male mice and evaluated histological, macroscopical, and morphological analysis at 0 days. Next, we created the ACL-R, controlled abnormal tibial translation (CATT), and Sham groups. Then, the joint stability and OA pathophysiology were analyzed at 2, 4, and 8 weeks. No intra-articular injuries, except for ACL rupture, were observed in the ACL-R model. ACL-R mice increased anterior tibial displacement compared to the Sham group (P<0.001, 95% CI [-1.509 to-0.966]) and CATT group (P<0.001, 95% CI [-0.841 to-0.298]) at 8 weeks. All mice in the ACL-R group caused cartilage degeneration. The degree of cartilage degeneration in the ACL-R group was higher than in the CATT group (P=0.006) at 8 weeks. The MMP-3-positive cell rate of chondrocytes increased in the ACL-R group than CATT group from 4 weeks (P=0.043; 95% CI [-28.32 to-0.364]) while that of synovial cells increased at 8 weeks (P=0.031; 95% CI [-23.398 to-1.021]). We successfully established a Non-invasive ACL-R model without intra-articular damage. Our model revealed that chondrocytes might react to abnormal mechanical stress prior to synovial cells while the knee OA onset.

Biomechanical effects of medial meniscus radial tears on the knee joint during gait: A concurrent finite element musculoskeletal framework investigation.

The biomechanical variation in the knee during walking that accompanies medial meniscal radial tears stemming from knee osteoarthritis (OA) has not been explored. This study introduced a finite element musculoskeletal model using concurrent lower limb musculoskeletal dynamics and knee joint finite element analysis in a single framework and expanded the models to include knees with medial meniscal radial tears and total medial meniscectomy. The radial tears involved three locations: anterior horn, midbody, and posterior horn with grades of 33%, 50%, and 83% of the meniscus width. The shear and hoop stresses of the tear meniscus and tibial cartilage contact load, accompanying tears, and postmeniscectomy were evaluated during the stance phase of the gait cycle using the models. In the 83% width midbody tear group, shear stress at the end of the tear was significantly greater than in the intact meniscus and other tear groups, and the maximum shear stress was increased by 310% compared to the intact meniscus. A medial meniscus radial tear has a much smaller effect on the tibial cartilage load (even though in the 83% width tear, the cartilage/total load ratio increased by only 9%). However, the contact force on the tibial cartilage with total postmeniscectomy was increased by 178.93% compared with a healthy intact meniscus, and the peak contact pressure after meniscectomy increased from 11.94 to 12.45 MPa to 17.64 and 13.76 MPa, at the maximum weight acceptance and push-off, respectively. Our study shows that radial tears with larger medial meniscus widths are prone to high stress concentrations at the end of the tears, leading to the potential risk of complete meniscal rupture. Furthermore, although the tears did not change the cartilage load distribution, they disrupted the circumferential stress-transmitting function of the meniscus, thus greatly increasing the likelihood of the onset of knee OA. The significant increase in the tibial cartilage load with total postmeniscectomy indicates a potential risk of OA flare-ups. This study contributes to a better understanding of meniscal tear-induced OA biomechanical changes during human activities and offers some potential directions for surgical guidance of meniscectomies and the prophylaxis and treatment of OA.

Long-term (10-25 years) outcomes of knee osteochondral autologous transplantation in soccer players

ObjectiveOsteochondral lesions in the knee can occur in a high percentage of soccer players. Untreated, symptomatic osteochondral lesions can lead to reduced athletic performance, early career-ending, and the premature onset of knee osteoarthritis. One of the treatment options is osteochondral autologous transplantation with the mosaicplasty technique. The study aims to investigate the long-term outcomes of the procedure in the athletic population. DesignIn a single-center retrospective study, the long-term outcomes of knee mosaicplasty procedures in soccer players between 1992 and 2011 were investigated. Using International Knee Documentation Committee and Bandi score to evaluate the knee function, Tegner score to measure activity, and MOCART 2.0 score to describe cartilage surface. Players' skill level was divided into professional, competitive, and recreational groups. ResultsFifty-five out of 73 soccer players were included; 25 had MRI at the last follow-up control. The average follow-up time was 17,54 years (10,32-24,91). The mean International Knee Documentation Committee score was 68.52 ± 16.01 (33-87), MOCART was 70.8 ± 18.12 (25-95), and 80% of the patient had a good Bandi score. The mean size of the defects was 2,08 cm2 ± 1,19 (1-5 cm2) and overall return to sport time was 7,78 ± 2,96 (4-12) months. ConclusionThe knee mosaicplasty procedure has a good long-term result, with no significant decrease in functional scores compared to other studies even after 20 years from the surgery. Therefore, osteochondral autologous transplantation is a reasonable option for soccer players with small to medium-sized osteochondral lesions in the knee.

GIVING ATHLETES A VOICE TO IMPROVE PRIMARY OA PREVENTION PRACTICE IN SPORT

Purpose: Previous knee joint injury, such as an anterior cruciate ligament (ACL) rupture, is one of the strongest risk factors for the onset of knee osteoarthritis (OA). One in two people who sustain an ACL injury will develop knee OA before the age of 40. ACL injuries are common in high-risk sports that require athletes to jump, land and pivot, with women at 2-8 times greater risk than men. Primary OA prevention strategies, such as exercise-based ACL injury prevention programs, can reduce ACL injury among women by 67%.

Anterior cruciate ligament innervation in primary knee osteoarthritis.

To relate the Anterior Cruciate Ligament (ACL) innervation and histologic degeneration status to the knee osteoarthritis radiologic and functional status. Prospective observational study including 30 consecutive patients affected by primary knee osteoarthritis undergoing Total Knee Arthroplasty (TKA). All patients suffering secondary knee osteoarthritis, an antecedent of an infectious process, malignant process, autoimmune disorder, or previous knee surgery were excluded. We recorded biodemographic, clinical, and radiologic variables of all participants previous to the TKA procedure. ACL tissue was harvested during TKA standard procedure and the obtained sample was fixed in 4% formalin and paraffin-embedded. ACL cross-sections were stained by haematoxylin-eosin and Gallego staining for elastic and collagen fibers, and Sevier-Munger silver staining for nervous tissue. ACL samples histologic degeneration classification reported 15.4% normal, 23.1% slight, 26.9% mild, 11.5% moderate and 23.1% marked. We noted 46.2% large nervous fascicles, 15.4% medium fascicles, 3.8% small fascicles, and no nerve fibers were found in 34.6% ACL samples. No significant correlation was found between the histologic degeneration and the nervous fiber quantification (p>0.05, in all cases). We noted a significant histologic degeneration inverse correlation with the VAS scale (p=0.016), and nervous fiber quantification correlation with Lequesne maximum distance walked punctuation (p=0.043). We also noted greater nervous fiber quantification with minor radiological knee osteoarthritis (Kellgren-Lawrence grade II). ACL degeneration and innervation deficit may play a role in primary knee osteoarthritis onset, but the lack of a defining relationship among the different parameters assessed justifies further research in greater populations.

The difference in joint instability affects the onset of cartilage degeneration or subchondral bone changes

It has been debated whether the onset of knee osteoarthritis is initiated in cartilage or subchondral bone. The purpose of this study was to clarify the effects of increasing or decreasing joint instability on cartilage degeneration and subchondral bone changes in knee OA by comparing different models of joint instability. We used the anterior cruciate ligament transection (ACL-T) model and the destabilization of the medial meniscus (DMM) model. In addition, we created a controlled abnormal tibial translation (CATT) model and a controlled abnormal tibial rotation (CATR) model. We performed joint instability analysis, micro-computed tomography analysis, histological and immunohistological analysis in 4 and 6 weeks. The CATT group suppressed joint instability in the ACL-T group (6 weeks; P=0.032), and the CATR group suppressed joint instability in the DMM group (6 weeks; P=0.032). Chondrocyte hypertrophy in the ACL-T and DMM groups was increased compared to the Sham group (6 weeks; [ACL-T vs Sham], P=0.002, 95%CI [5.983-33.025]; [DMM vs Sham], P=0.022, 95%CI [1.691-28.733]). In the subchondral bone, the BV/TV in the DMM and CATR groups was increased compared to the ACL-T and CATT groups (6 weeks; [DMM vs ACL-T], P=0.002, 95%CI [7.404-37.582]; [DMM vs CATT], P=0.014, 95%CI [2.881-33.059]; [CATR vs ACL-T], P=0.006, 95%CI [4.615-34.793]; [CATR vs CATT], P=0.048, 95%CI [0.092-30.270]). This study showed that joint instability promotes chondrocyte hypertrophy, but subchondral bone changes were influenced by differences in ACL and meniscus function.

Persistent quadriceps activation failure reduces in ACL reconstructed patients submitted to strength training based on force steadiness and visual feedback

Background:Quadriceps activation failure after anterior cruciate ligament reconstruction (ACLr) is related to the inhibition of alpha-motor units and results in muscle weakness. The quadriceps activation failure limits the rehabilitation outcomes, especially strength gains that are essential to the return to sport and to minimize the risk for the onset of knee osteoarthritis. Exercises involving force steadiness could reduce the variability of motor unit discharge rate and contribute to the force enhancement. On the other hand, force steadiness during isometric contractions involves controlling the fluctuations in the force signals, which might be enhanced by visual feedback. Therefore, the combination of force steadiness and visual feedback could have potential benefits for patients with persistent quadriceps activation failure.Objectives:To determine the effect of strength training with force steadiness and visual feedback on knee extension torque, knee stability, and knee pain in patients with persistent quadriceps activation failure after ACLr.Methods:Twenty-five patients (43.7±12.2 years-old, 69.8±10.8 kg, and 1.69±0.09 m, 10 men) with persistent quadriceps activation failure after ACLr non-responders to a conventional rehabilitation protocol were included in this case series. All protocols were approved by the local institutional ethics board. Persistent quadriceps activation failure was diagnosed based on the clinical history, temporal diphase with physical therapy protocol, non-gain of quadriceps strength after around 20 sessions of physiotherapy in the 9th month of rehabilitation, quadriceps weakness in the clinical examination, and abnormal isokinetic assessment (peak extensor torque<100 Nm, asymmetry in peak extensor torque>50%, or asymmetry in peak torque>70 Nm). All patients were submitted to an ACLr surgery performed by the same surgeon with semitendinosus-gracilis autograft. The intervention considered three sessions/week and lasted until 20 sessions or auto-perception of functional knee stability. The intervention and torque measurements were performed with an isokinetic device. A warmed up for 10 minutes on a cycle ergometer without load (60 rpm) was performed. After, they performed knee extension following a trapezoid curve feedback. Due to strength unbalances between ACLr and non-ACLr limbs, we used five series of 8 and 5 repetitions, respectively. The training was performed at a workload between 60% and 70%. Knee extension peak torque was determined at baseline and after training protocol. Proportions of responders and non-responders were extracted considering a threshold of 25.02 Nm. Knee pain (any painful feeling at the knee developed between the last and new session) and stability (same knee stiff sensation when they had not suffered the ACL injury) were also assessed as a binary proportion. A mixed ANOVA with 2 factors [time (before and after intervention), and limb (ACLr and non-ACLr limb)] was performed to compare the knee extension peak torque. To compare the proportion of intervention responders, knee stability, and pain before and after intervention the 2-tailed McNemar test was performed.Results:Training improved knee extension peak torque in the ACLr limb (98.2±47.2 to 155.2±78.9, Δ=57.0 Nm, p=0.031) and the non-ACLr (169.6±86.9 to 209.5±101.8, Δ=39.9 Nm, p=0.178). At baseline, lower torque was found in the ACLr limb (169.6±86.9 vs. 98.2±47.2, Δ=71.4, p=0.003) and remain different after training protocol (209.5±101.8 vs. 155.2±78.9, Δ= 54.3, p=0.026). Most of the patients (84%) increased knee extension peak torque (p<0.001), 72% increased self-reported knee stability (p<0.001), and 52% decreased knee pain (p<0.001).Conclusion:Strength training with force steadiness and visual feedback was an effective intervention to improve knee extensor torque in ACLr patients with persistent quadriceps activation failure identified 9 months after an auto-graph ACL surgery. We found that 21 out of 25 patients were able to respond positively to the intervention. The intervention also improved the self-report of stability and pain. Although the difference in torque between limbs suggests that the asymmetries persisted after the intervention. This intervention might be the first rehabilitation stage in persistent quadriceps activation failure. The next rehabilitation stage to normalize the inter-limb strength needs to be explored.