Risk Of Posttraumatic Osteoarthritis Research Articles

The Relationship Between Intra-articular Fracture Energy and a Patient's Inflammatory Response.

Prior studies have demonstrated elevated inflammatory cytokine concentrations in the synovial fluid of articular fracture patients postinjury. Similarly, CT-based fracture energy measurements have been correlated with posttraumatic osteoarthritis risk after pilon fracture. The purpose of this study was to determine the associations between synovial fluid cytokine levels, fracture energy, and overall trauma to the body in articular fracture patients. Acute tibial plateau, tibial plafond, and rotational ankle fracture patients were prospectively enrolled from December 2011 through January 1, 2019. Synovial fluid concentrations of interleukin-1 beta, interleukin-1 receptor antagonist, IL-6, IL-8, IL-10, matrix metallopeptidase-1, MMP-3, and MMP-13 were quantified. Patient CT scans were used to calculate fracture energy. The Injury Severity Score (ISS) was used to relate cytokine levels to whole-body injury severity. Spearman rho correlation coefficients were calculated to assess the relationship between injury severity metrics and synovial fluid cytokine, chemokine, and matrix metallopeptidase concentrations. Eighty-seven patients were enrolled with 42 had a tibial plateau fractures (OTA/AO 41B1-2, 41B2-14, 41B3-3, 41C1-3, 41C2-4, 41C3-16), 24 patients had a tibial plafond fracture (OTA/AO 43B1-2, 43B2-4, 43B3-5, 43C1-2, 43C2-3, 43C3-8), and 21 had a rotational ankle fracture (OTA/AO 44B1-3, 44B2-3, 44B3-6, 44C1-4, 44C2-5). Fracture energy significantly differed between fracture patterns, with ankle fractures involving substantially less fracture energy (median = 2.92 J) than plafond (10.85 J, P < 0.001) and plateau fractures (13.05 J, P < 0.001). After adjustment for multiple comparisons, MMP-3 was significantly correlated with transformed fracture energy (r = 0.41, 95% confidence interval [CI], 0.22-0.58, P < 0.001), while IL-1β was significantly correlated with the Injury Severity Score (Spearman ρ = 0.31, 95% CI, 0.08-0.49, P = 0.004). Synovial fluid MMP-3 concentration was significantly correlated with CT-quantified fracture energy in intra-articular fracture patients. Given that in clinical practice fracture energy tends to correlate with posttraumatic osteoarthritis risk, MMP-3 may warrant further investigation for its role in posttraumatic osteoarthritis development after articular fracture. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Efficacy ofa Novel Telehealth Application inHealth Behavior Modification andSymptomology inMilitary Service Members at Risk forPost-traumatic Osteoarthritis.

Mobile applications (apps) may be beneficial to promote self-management strategies to mitigate the risk of developing post-traumatic osteoarthritis in military members following a traumatic knee injury. This study investigated the efficacy of a mobile app in facilitating behavior modification to improve function and symptomology among military members. This is a preliminary pre and post hoc analysis of a randomized control trial. The MARX scale, Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire, and the Knee Injury and Osteoarthritic Outcome Score Readiness to Manage Osteoarthritis Questionnaire were completed at baseline, 6-week, 6-month, and 12-month follow-up. Participants in the treatment arm completed the System Usability Scale. Data were analyzed using descriptive statistics, the Wilcoxon sum of ranks test, the Wilcoxon signed-rank test, and Cohen's d effect size. A total of 28 participants were included. Between-group differences for baseline and 6-week follow-up were significantly improved in the injured knee ICOAP constant pain score for the treatment group (treatment: -4.2 ± 12, 95% CI: -11.5, 3.1; control: 5.5 ± 9.9, 95% CI: 0.9, 10.1; P = .035, effect size=0.905). Within-group differences for baseline and 6-week follow-up demonstrated a significant decline in the injured knee ICOAP constant pain score among the control group (signed-rank: 16.0, P = .031, Cohen's d=0.339). No other significant differences were observed. A good System Usability Scale score for usability was found (76.6±8.8). These results indicate that the mobile app is easy to use and may contribute to improved constant pain symptomology for patients at risk for post-traumatic osteoarthritis.

Long-Term Bilateral Neuromuscular Function and Knee Osteoarthritis after Anterior Cruciate Ligament Reconstruction.

Neuromuscular function is thought to contribute to posttraumatic osteoarthritis (PTOA) risk in anterior cruciate ligament (ACL)-reconstructed (ACLR) patients, but sensitive and easy-to-use tools are needed to discern whether complex muscle activation strategies are beneficial or maladaptive. Using an electromyography (EMG) signal analysis technique coupled with a machine learning approach, we sought to: (1) identify whether ACLR muscle activity patterns differed from those of healthy controls, and (2) explore which combination of patient outcome measures (thigh muscle girth, knee laxity, hop distance, and activity level) predicted the extent of osteoarthritic changes via magnetic resonance imaging (MRI) in ACLR patients. Eleven ACLR patients 10-15 years post-surgery and 12 healthy controls performed a hop activity while lower limb muscle EMG was recorded bilaterally. Osteoarthritis was evaluated based on MRI. ACLR muscle activity patterns were bilaterally symmetrical and differed from those of healthy controls, suggesting the presence of a global adaptation strategy. Smaller ipsilateral thigh muscle girth was the strongest predictor of inferior MRI scores. The ability of our EMG analysis approach to detect meaningful neuromuscular differences that could ultimately be related to thigh muscle girth provides the foundation to further investigate a direct link between muscle activation patterns and PTOA risk.

Malunion of the distal radius: 3Dplanning and performance of intra- and extra-articular corrective osteotomy

Restoration of the original anatomy with reduction of both current symptoms and risk of posttraumatic osteoarthritis. Symptomatic intra- or extra-articular malunion due to limitation of movement and/or painful function, intra-articular step of > 1 mm, instability of the distal radioulnar joint. Minimal deformity. Pre-existing osteoarthritis Knirk and JupiterII or higher. Simpler surgical alternative, e.g., ulna shortening osteotomy. Smoking or advanced age are not contraindications. Preoperative assessment and performance of abilateral computed tomography (CT). Three-dimensional (3D) malposition analysis and calculation of the correction. Planning of the corrective osteotomy on the 3D model and creation of patient-specific drilling and sawing guides. Performing the 3D-guided osteotomy. Early functional unloaded mobilization with the splint for 8weeks until consolidation control with CT. Significant reduction of the step to < 1 mm (p ≤ 0.05) can be achieved with intra-articular corrections. In extra-articular corrective osteotomies, amean residual rotational malalignment error of2.0° (± 2.2°) and atranslational malalignment error of 0.6 mm (± 0.2 mm) is achieved. Single-cut osteotomies in the shaft region can be performed to within afew degrees for rotation (e.g., pronation/supination4.9°) and for translation (e.g., proximal/distal, 0.8 mm). After surgery, amean residual 3D angle of5.8° (SD3.6°) was measured. Furthermore, surgical time for 3D-assisted surgery is significantly reduced compared to the conventional technique (140 ± 37 vs 108 ± 26 min; p < 0.05). Thus, the progression of osteoarthritis can be reduced in the medium term and improved mobility and grip strength are achieved. The clinical outcome parameters based on patient-rated wrist evaluation (PRWE) and the disabilities of the arm, shoulder and hand (DASH) scores are roughly comparable.

Radiomics Feature Analysis of Cartilage and Subchondral Bone in Differentiating Knees Predisposed to Posttraumatic Osteoarthritis after Anterior Cruciate Ligament Reconstruction from Healthy Knees.

Objectives To introduce a new implementation of radiomics analysis for cartilage and subchondral bone of the knee and to compare the performance of the proposed models to classic T2 relaxation time in distinguishing knees predisposed to posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament reconstruction (ACLR) and healthy controls. Methods 114 patients following ACLR after at least 2 years and 43 healthy controls were reviewed and allocated to training (n = 110) and testing (n = 47) cohorts. Radiomics models are built for cartilage and subchondral bone regions of different compartments: lateral femur (LF), lateral tibia (LT), medial femur (MF), and medial tibia (MT) and combined models of four compartments on T2 mapping images. The model performance of discrimination between patients and controls was illustrated with the receiver operating characteristic curve and compared with a classic T2 value-based model. Results The T2 value model of cartilage yielded moderate predictive performance in discerning patients and controls, with an AUC of 0.731 (95% confidence interval, 0.556–0.875) in the testing cohort, while the radiomics signature of cartilage and subchondral bone of different compartments demonstrated excellent performance, with AUCs of 0.864–0.979. Furthermore, the combined model reported an even better performance, with AUCs of 0.977 (95% confidence interval, 0.919–1.000) for the cartilage and 0.934 (95% confidence interval, 0.865–0.994) for the subchondral bone in the testing cohort. Conclusion The radiomics features of the cartilage and subchondral bone may be able to provide powerful tools with more sensitive detection than T2 values in differentiating knees at risk for PTOA after ACLR from healthy knees.

Primary total knee replacement for tibial plateau fractures in older patients: a systematic review of 197 patients

IntroductionTibial plateau fractures are typically treated with osteosynthesis. In older patients, osteosynthesis is associated with some complications, risk of post-traumatic osteoarthritis and long partial, or non-weight bearing during the recovery phase. To avoid these problems, primary total knee replacement (TKR) has become an increasingly common treatment option. The aim of this study was to evaluate all the relevant literature and summarize the current evidence-based knowledge on the treatment of tibial plateau fractures with primary TKR in older patients.Materials and methodsA systematic literature search of studies on total knee replacement (TKR) as primary treatment for acute traumatic tibial plateau fracture was conducted using OVID Medline, Scopus, and Cochrane databases from 1946 to 18 November 2019. We included all studies without restrictions regarding total knee replacement (TKR) as primary treatment for acute traumatic tibial plateau fracture.ResultsOf the 640 reviewed articles, 16 studies with a total of 197 patients met the inclusion criteria. No controlled trials were available, and the overall quality of the literature was low. The results, using different clinical scoring systems, were good or fair. Four-year follow-up complication (6.1%) and revision (3.6%) rates after primary TKR appeared to be lower than after secondary TKR (complication rate 20–48%, revision rate 8–20%) but higher than after elective primary TKR.ConclusionBased on low-quality evidence, TKR appears to be a useful treatment option for tibial plateau fractures in older patients. Controlled trials are mandatory to determine the relative superiority of these two options as primary treatment of tibial plateau fractures in older patients.

Time waits for no one - a preliminary analysis of an inception matched-pair cohort study of youth sport knee injury

Purpose: Knee injuries are associated with a 6-fold increased risk of post-traumatic osteoarthritis (PTOA) and 7-fold increased odds of arthroplasty. Although less prevalent than idiopathic osteoarthritis (OA), PTOA is accompanied by a greater number of years lived with disability due in part to a younger age of onset. Best evidence suggests that PTOA may be amenable to prevention and early treatment. We have previously demonstrated that youth who experience a wide range of sport-related knee injuries demonstrate greater knee-related symptoms, physical dysfunction, muscle weakness, and adiposity within 3-10 years compared to matched uninjured youth and this may compound their risk for PTOA.

Long-term outcomes of anterior cruciate ligament reconstruction surgery: 2020 OREF clinical research award paper.

ACL injuries place the knee at risk for post-traumatic osteoarthritis (PTOA) despite surgical anterior cruciate ligament (ACL) reconstruction. One parameter thought to affect PTOA risk is the initial graft tension. This randomized controlled trial (RCT) was designed to compare outcomes between two graft tensioning protocols that bracket the range commonly used. At 7 years postsurgery, we determined that most outcomes between the two tension groups were not significantly different, that they were inferior to an uninjured matched control group, and that PTOA was progressing in both groups relative to controls. The trial database was also leveraged to gain insight into mechanisms of PTOA following ACL injury. We determined that the inflammatory response at the time of injury undermines one of the joint's lubricating mechanisms. We learned that patients continue to protect their surgical knee 5 years postinjury compared to controls during a jump-pivot activity. We also established that presurgical knee function and mental health were correlated with symptomatic PTOA at 7 years, that there were specific anatomical factors associated with poor outcomes, and that there were no changes in outcomes due to tunnel widening in patients receiving hamstring tendon autografts. We also validated a magnetic resonance imaging technique to noninvasively assess graft strength. In conclusion, the RCT determined that initial graft tensioning does not have a major influence on 7-year outcomes. Therefore, surgeons can reconstruct the ACL using a graft tensioning protocol that is within the window of the two graft tensioning techniques evaluated in this RCT.

How health outcomes differ between youth who suffer a traumatic, sport-related knee injury and matched controls - implications for rehabilitation and understanding post-traumatic osteoarthritis risk

How health outcomes differ between youth who suffer a traumatic, sport-related knee injury and matched controls - implications for rehabilitation and understanding post-traumatic osteoarthritis risk

Knee joint replacement as primary treatment for proximal tibial fractures: analysis of clinical results of twenty-two patients with mean follow-up of nineteen months.

Proximal tibial fractures are typically treated with osteosynthesis. In older patients, this method has been reported to be associated with a high complication rate, risk of post-traumatic osteoarthritis, and long partial or non-weight bearing during the recovery phase. To avoid these problems, primary total knee replacement (TKR) has become an increasingly common treatment option. Twenty-two patients (mean age 74years, SD 12) underwent primary TKR due to tibial plateau fracture. Follow-up data were available for a mean of 19 (SD 16) months. Trauma mechanism, fracture classification, type of prosthesis used, complications, and re-operations during the follow-up were recorded. The Knee Society Score (KSS), Oxford Knee Score (OKS), range of flexion, and patient satisfaction were evaluated. 13/22 of the fractures were due to a low-energy trauma. At final follow-up, mean KSS was 160 (SD 39) and mean OKS 27 (SD 11) points. Mean flexion was 109° (SD 16°). 14/17 of the patients were satisfied or highly satisfied with their post-operative knee and 11/17 reported their knee to be same or better than pre-trauma. 2/22 of the patients had complications requiring revision surgery. TKR as a primary definitive method seems to be a useful alternative to osteosynthesis, enabling immediate full weight bearing and rapid mobilization of patients. The risk of complications associated with primary TKR is higher than those reported after TKR due to primary osteoarthritis but lower than those reported after TKR due to secondary osteoarthritis.

Poor Performance on Single-Legged Hop Tests Associated With Development of Posttraumatic Knee Osteoarthritis After Anterior Cruciate Ligament Injury.

Background:The risk for knee osteoarthritis (OA) is substantially increased after anterior cruciate ligament (ACL) injury. Tools are needed to identify characteristics of patients after ACL injury who are most at risk for posttraumatic OA.Purpose:To determine whether clinical measures of knee function after ACL injury are associated with the development of radiographic knee OA 5 years after injury.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 76 athletes (mean age, 28.7 ± 11.3 years; 35.5% female) with ACL injury were included. Clinical measures of knee function (quadriceps strength, single-legged hop tests, patient-reported outcomes) were assessed after initial impairment resolution (baseline), after 10 additional preoperative or nonoperative rehabilitation sessions (posttraining), and 6 months after ACL reconstruction or nonoperative rehabilitation. Posterior-anterior bent-knee radiographs were completed at 5 years and graded in the medial compartment by use of the Kellgren-Lawrence system. Logistic regression models were used at each of the 3 time points to determine the ability of clinical measures to predict knee OA at 5 years.Results:Of the 76 patients, 9 (11.8%) had knee OA at 5 years. After adjustment for ACL reconstruction compared with nonoperative management, ipsilateral second ACL injuries, and the presence of contralateral knee OA, clinical measures of knee function at posttraining (6-m timed hop, Knee Outcomes Survey–Activities of Daily Living Scale) explained the most variance in posttraumatic OA development at 5 years (P = .006; ▵R 2, 27.5%). The 6-m hop test was the only significant posttraining predictor of OA at 5 years (P = .023; patients without OA, 96.6% ± 5.4%; patients with OA, 84.9% ± 14.1%). Similar significant group differences in hop scores and subjective knee function were present at baseline. No significant group differences in clinical measures existed at 6 months after ACL reconstruction or nonoperative rehabilitation.Conclusion:Poor performance in single-legged hop tests early after ACL injury but not after reconstruction or nonoperative rehabilitation is associated with the development of radiographic posttraumatic knee OA 5 years after injury. Clinical measures of knee function were most predictive of subsequent OA development following an extended period of rehabilitation early after ACL injury.

Gait mechanics and tibiofemoral loading in men of the ACL-SPORTS randomized control trial.

The risk for post-traumatic osteoarthritis is elevated after anterior cruciate ligament reconstruction (ACLR), and may be especially high among individuals with aberrant walking mechanics, such as medial tibiofemoral joint underloading 6 months postoperatively. Rehabilitation training programs have been proposed as one strategy to address aberrant gait mechanics. We developed the anterior cruciate ligament specialized post-operative return-to-sports (ACL-SPORTS) randomized control trial to test the effect of 10 post-operative training sessions consisting of strength, agility, plyometric, and secondary prevention exercises (SAPP) or SAPP plus perturbation (SAPP + PERT) training on gait mechanics after ACLR. A total of 40 male athletes (age 23 ± 7 years) after primary ACLR were randomized to SAPP or SAPP + PERT training and tested at three distinct, post-operative time points: 1) after impairment resolution (Pre-training); 2) following 10 training sessions (Post-training); and 3) 2 years after ACLR. Knee kinematic and kinetic variables as well as muscle and joint contact forces were calculated via inverse dynamics and a validated electromyography-informed musculoskeletal model. There were no significant improvements from Pre-training to Post-training in either intervention group. Smaller peak knee flexion angles, extension moments, extensor muscle forces, medial compartment contact forces, and tibiofemoral contact forces were present across group and time, however the magnitude of interlimb differences were generally smaller and likely not meaningful 2 years postoperatively. Neither SAPP nor SAPP + PERT training appears effective at altering gait mechanics in men in the short-term; however, meaningful gait asymmetries mostly resolved between post-training and 2 years after ACLR regardless of intervention group. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2364-2372, 2018.

Gait mechanics and tibiofemoral loading in men of the ACL-Sports randomized control trial

The risk for post-traumatic osteoarthritis is elevated after anterior cruciate ligament reconstruction (ACLR), and may be especially high among individuals with aberrant walking mechanics, such as medial tibiofemoral joint underloading 6 months postoperatively. Rehabilitation training programs have been proposed as one strategy to address aberrant gait mechanics. We developed the anterior cruciate ligament specialized post-operative return-to-sports (ACL-SPORTS) randomized control trial to test the effect of 10 post-operative training sessions consisting of strength, agility, plyometric, and secondary prevention exercises (SAPP) or SAPP plus perturbation (SAPP + PERT) training on gait mechanics after ACLR. A total of 40 male athletes (age 23 ± 7 years) after primary ACLR were randomized to SAPP or SAPP + PERT training and tested at three distinct, post-operative time points: 1) after impairment resolution (Pre-training); 2) following 10 training sessions (Post-training); and 3) 2 years after ACLR. Knee kinematic and kinetic variables as well as muscle and joint contact forces were calculated via inverse dynamics and a validated electromyography-informed musculoskeletal model. There were no significant improvements from Pre-training to Post-training in either intervention group. Smaller peak knee flexion angles, extension moments, extensor muscle forces, medial compartment contact forces, and tibiofemoral contact forces were present across group and time, however the magnitude of interlimb differences were generally smaller and likely not meaningful 2 years postoperatively. Neither SAPP nor SAPP + PERT training appears effective at altering gait mechanics in men in the short-term; however, meaningful gait asymmetries mostly resolved between post-training and 2 years after ACLR regardless of intervention group. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2364-2372, 2018.

Arthroscopically Assisted Fixation of the Tibial Plateau Fractures

Objectives: To consolidate the current literature and find the evidence of any advantages of the use of the above mentioned techniques and also to emphasize the need for well-designed studies to evaluate long- and short-term function and risk of posttraumatic osteoarthritis in arthroscopically-assisted treated patients.Background: The role of arthroscopy in the fixation of tibial plateau fractures has been advocated in the literature in the last decades. A number of papers have been published regarding Arthroscopically Assisted Internal Fixation (mainly) and Arthroscopically Assisted External Fixation (significantly smaller amount of papers) of tibial plateau fractures.Materials and Methods: 29 studies including 983 patients were identified via Pubmed search. Most of them are small studies, poorly controlled and with potential bias.Results: Despite the small amount of studies comparing ARIF with ORIF technique and studies with an average follow up longer than 3 years), the advocates of ARIF suggest, that this technique can have a key role in the management of tibial plateau fractures and is the treatment of choice for associated intra-articular pathology. Nevertheless, most of these studies, if not all, are selected, small studies, poorly controlled and with potential bias.Conclusions: There is a need for well-designed studies to evaluate long- and short-term function and risk of posttraumatic osteoarthritis in arthroscopically-assisted treated patients.

3D Correlation Mapping between Changes in Cartilage T1ρ and Thickness Over 1-year after ACL Reconstruction using Atlas-based Methods

Purpose: Subjects with anterior cruciate ligament (ACL) injury are at risk for post-traumatic osteoarthritis (PTOA). T1ρ MRI has been used to detect early degeneration after ACL injury and reconstruction. Previous studies also revealed significant changes in cartilage thickness after ACL injury, with thickness increasing in some compartments while decreasing in other compartments. However, the correlation between the change in T1ρ and the change in cartilage thickness has not been demonstrated. A better understanding of these correlations will help with staging the cartilage degeneration status after ACL injury. Very recently, a novel atlas-based method was developed which permits voxel-based relaxometry analysis (VBR). The goal of this study was to apply the atlas-based method to evaluate the local voxel-by-voxel correlation between changes in T1ρ and changes in thickness from baseline to 6-months and 1-year after ACL reconstruction (ACLR). Methods: Bilateral knees were scanned using a 3T MRI scanner for twenty-five patients with ACL injuries prior to surgical reconstruction (baseline, BL), and 6-months (6M) and 1-year (1Y) after ACLR (age = 28.4 ± 8.2 years, BMI = 23.8± 2.7 kg/m2, 10 female). The imaging protocol included the 3D MAPSS T1ρ/T2 sequence used for cartilage relaxation times quantification and high-resolution 3D FSE (CUBE) used for WORMS grading and semi-automatic cartilage segmentation. Those segmentations were used to define a voxel based thickness map for each subject. An atlas based registration approach was then used to morph all the T1ρ-weighted images and the thickness maps to the same reference space, and T1ρ maps were computed in the atlas space allowing for voxel-by-voxel correspondence between T1ρ and thickness. Longitudinal changes in cartilage thickness and T1ρ, as well as the local Pearson correlation coefficients between changes in T1ρ and changes in thickness were calculated voxel-by-voxel. Both analyses were adjusted for age, gender and BMI. The level of significance was set at p<0.05. Percentage of significant voxel (PSV, %) with positive or negative correlation and the mean value of correlation coefficients (R) were calculated in each compartment. Results: Significant increases of T1ρ in MFC and trochlea, and significant decreases of T1ρ in patella were observed; while significant increases of cartilage thickness in patella and significant decreases of cartilage thickness in trochlea were observed (Fig. 1 A–B). The most significant correlation between changes in T1ρ and changes in thickness was observed in patella, LFC, trochlea and MFC (Fig. 1C). In the patella, significant negative correlation was found between changes in T1ρ and changes in thickness from BL to 6M (38.4% voxels, R=−0.536) and from BL to 1Y (15.1% voxels, R=−0.590) (Tab1). This correlation was primarily the result of a decrease in T1ρ and an increase in thickness, while in other compartments, the negative correlations primarily resulted from an increase in T1ρ and a decrease in thickness. From 6M to 1Y, in LFC, a large decrease of the positive correlation PSV (from 11.2% to 2.5%) and a slight increase of negative correlation PSV were observed. There is an increasing trend of the total cartilage WORMS scores from BL (2.0±2.1) to 6M (2.2±2.1) and 1Y (2.4±2.3), but the increase was not significant. Conclusions: In this study, the local correlation between changes in cartilage matrix composition and changes in cartilage thickness was analyzed voxel-by-voxel using a novel 3D atlas-based method. Significant correlations were observed between ΔT1ρ and ΔΤhickness from BL to 6M and 1Y after ACLR. A positive correlation with increase in T1ρ and thickness may suggest the cartilage is at very early stages of degeneration with tissue swelling; while a negative correlation with increase in T1ρ and decrease in thickness may suggest later stages that cartilage begins to experience tissue loss. From 6M to 1Y, there is a general trend of decreasing positive correlation percentage while an increasing negative correlation percentage (Figure 2) in the femoral condyles and trochlea, suggests a progression of cartilage degeneration, confirmed by change in WORMS. In patella, the negative correlation was driven by the decrease of T1ρ and increase of thickness, which may be associated with changes in loading to patella-femoral joint (PFJ) as well as changes in activities after ACLR. Longer follow-up analysis is warranted to better understand cartilage degeneration progression after ACL injury. Funding from NIH/NIAMS P50 AR060752.

Certified Athletic Trainers' Knowledge and Perceptions of Posttraumatic Osteoarthritis After Knee Injury.

Posttraumatic osteoarthritis (PTOA) is a specific phenotype of osteoarthritis (OA) that commonly develops after acute knee injury, such as anterior cruciate ligament (ACL) or meniscal injury (or both). Athletic trainers (ATs) are well positioned to educate patients and begin PTOA management during rehabilitation of the acute injury, yet it remains unknown if ATs currently prioritize long-term outcomes in patients with knee injury. To investigate ATs' knowledge and perceptions of OA and its treatment after ACL injury, ACL reconstruction, or meniscal injury or surgery. Cross-sectional study. An online survey was administered to 2000 randomly sampled certified ATs. We assessed participants' perceptions of knee OA, the risk of PTOA after ACL or meniscal injury or surgery, and therapeutic management of knee OA. Of the 437 ATs who responded (21.9%), the majority (84.7%) correctly identified the definition of OA, and 60.3% indicated that they were aware of PTOA. A high percentage of ATs selected full meniscectomy (98.9%), meniscal tear (95.4%), ACL injury (90.2%), and partial meniscectomy (90.1%) as injuries that would increase the risk of developing OA. Athletic trainers rated undertaking strategies to prevent OA development in patients after ACL injury or reconstruction (73.8%) or meniscal injury or surgery (74.7%) as extremely or somewhat important. Explaining the risk of OA to patients with an ACL or meniscal injury was considered appropriate by 98.8% and 96.8% of respondents, respectively; yet a lower percentage reported that they actually explained these risks to patients after an ACL (70.8%) or meniscal injury (80.6%). Although 84.7% of ATs correctly identified the definition of OA, a lower percentage (60.3%) indicated awareness of PTOA. These results may reflect the need to guide ATs on how to educate patients regarding the long-term risks of ACL and meniscal injuries and how to implement strategies that may prevent PTOA.

Cross-sectional and longitudinal association between types of meniscal pathology and knee pain: Data from the osteoarthritis initiative

Cross-sectional and longitudinal association between types of meniscal pathology and knee pain: Data from the osteoarthritis initiative

Identification of meniscus damage biomarker: implications for the future treatment of knee injury

Knee pain is associated with a spectrum of various injuries and/or degradative states, which may be treated more specifically with regard to their particular etiologies. It is well established that knee injury leads to an increased risk of post-traumatic osteoarthritis and chronic knee pain [1–5]. However, joint pain from a specific injury may be a distinct entity from chronic, nontraumatic osteoarthritic pain. Furthermore, the biomolecular milieu of each specific injury resulting in knee pain may be more distinct from each other than usually appreciated (e.g., anterior cruciate ligament injury vs meniscal damage) [6,7]. Teasing out the characteristics of these various injuries is crucial, not only in diagnosis, but also in advancing our understanding of targeted treatment modalities. Whereas the symptoms, such as pain, may be similar across various knee injuries, the specific biomolecular environment and sequence of events may, in fact, be unique. To date, treatment of posttraumatic knee pain remains generalized, with practices focused on general suppression of inflammation (i.e., rest, ice, nonsteroidal antiinflammatory drugs and steroid injections). However, it is possible that the inflammatory milieu initiating pain may have subtle but consistent variables in each distinct pathology that offer targeted treatment opportunities. Presently, the diagnosis of intrinsic knee pathology relies heavily on imaging studies. For years, MRI has been the mainstay of diagnosis and subsequent treatment of symptomatic meniscal injury. However, the extent to which current imaging modalities provide targeted treatment is inherently limited. MRI generally has over 93% sensitivity and specificity for meniscal tears when compared with arthroscopy (the gold standard in diagnosis) [8]. Nonetheless, meniscal injury can be detected in up to 76% of asymptomatic patients by MRI [8–10]. Thus, as not all meniscal injuries are painful, its presence does not mandate treatment. It is important to distinguish between meniscal injury and painful meniscal injury. It is unclear at this time why some patients who sustain meniscal injury experience pain and others do not. Furthermore, it is unclear why some patients with knee injuries progress to develop chronic pain consistent with post-traumatic osteoarthritis. Recently, there has been an exponential increase in the number of studies evaluating these very subtleties, with an emphasis on the inflammatory component. Several studies have investigated inf lammatory markers in knee pain. Specific to meniscal damage, cytokines have been the primary focus, with IL-1, IL-6, TNF-a, IFN-g, MCP-1 and MIP-1b most frequently identified. Matrix metalloproteinases (MMPs) have also been extensively investigated, with studies suggesting that MMPs inhibit IL-1 activity and the meniscal response to healing [11]. Similarly, Lawrence et al. discuss the chondroprotective effect of inhibition of IL-1 and TNF-a, and potential modulation of the molecular environment after acute meniscal damage, in an effort to decrease the risks of post-traumatic osteoarthritis due to cartilage breakdown [12]. It is our belief that cytokine modulation after acute injury is key to regulating the inflammatory environment that sets the stage for post-traumatic osteoarthritis and pain. Particular cytokines may be involved in the genesis of pain and inflammation. While it is tempting to presume that blockade of these cytokines will alleviate pain and, maybe, the development of arthritis, further studies are needed to further delineate the roles of cytokines, growth factors and generalized inflammation, not only in pain generation but also in the processes of

Mechanical impact induces cartilage degradation via mitogen activated protein kinases

To determine the activation of Mitogen activated protein (MAP) kinases in and around cartilage subjected to mechanical damage and to determine the effects of their inhibitors on impaction-induced chondrocyte death and cartilage degeneration. The phosphorylation of MAP kinases was examined with confocal microscopy and immunoblotting. The effects of MAP kinase inhibitors on impaction-induced chondrocyte death and proteoglycan (PG) loss were determined with fluorescent microscopy and 1, 9-Dimethyl-Methylene Blue (DMMB) assay. The expression of catabolic genes at mRNA levels was examined with quantitative real-time PCR. Early p38 activation was detected at 20 min and 1h post-impaction. At 24h, enhanced phosphorylation of p38 and extracellular signal-regulated protein kinase (ERK)1/2 was visualized in chondrocytes from in and around impact sites. The phosphorylation of p38 was increased by 3.0-fold in impact sites and 3.3-fold in adjacent cartilage. The phosphorylation of ERK-1 was increased by 5.8-fold in impact zone and 5.4-fold in adjacent cartilage; the phosphorylation of ERK-2 increased by 4.0-fold in impacted zone and 3.6-fold in adjacent cartilage. Furthermore, the blocking of p38 pathway did not inhibit impaction-induced ERK activation. The inhibition of p38 or ERK pathway significantly reduced injury-related chondrocyte death and PG losses. Quantitative Real-time PCR analysis revealed that blunt impaction significantly up-regulated matrix metalloproteinase (MMP)-13, Tumor necrosis factor (TNF)-α, and ADAMTS-5 expression. These findings implicate p38 and ERK mitogen activated protein kinases (MAPKs) in the post-injury spread of cartilage degeneration and suggest that the risk of post-traumatic osteoarthritis (PTOA) following joint trauma could be decreased by blocking their activities, which might be involved in up-regulating expressions of MMP-13, ADAMTS-5, and TNF-α.