Lumbar Sympathetic Block for Treatment of Knee Pain From Synovial Plica Syndrome: A Case Report.

Lumbar sympathetic blocks (LSBs) are used to treat sympathetically mediated pain in the lower extremities, kidneys, ureters, and genitals. LSBs use local anesthetic to block the sympathetic system to modulate pain response. In this case report, an avid runner was diagnosed with synovial plica syndrome. His pain was refractory to arthroscopic plica excision, physical therapy, nonsteroidal anti-inflammatory drugs, and intraarticular steroid injections. He received 3 rounds of LSB resulting in significant and sustained pain relief. This case suggests that LSB successfully treated knee pain from synovial plica syndrome and there may be a sympathetic component to this disease state.

Comparison of joint kinematics between upright front squat exercise and horizontal squat exercise performed on a short arm human centrifugation.

This study compared the joint kinematics between the front squat (FS) conducted in the upright (natural gravity) position and in the supine position on a short arm human centrifuge (SAHC). Male participants (N = 12) with no prior experience exercising on a centrifuge completed a FS in the upright position before (PRE) and after (POST) a FS exercise conducted on the SAHC while exposed to artificial gravity (AG). Participants completed, in randomized order, three sets of six repetitions with a load equal to body weight or 1.25 × body weight for upright squats, and 1 g and 1.25 g at the center of gravity (COG) for AG. During the terrestrial squats, the load was applied with a barbell. Knee (left/right) and hip (left/right) flexion angles were recorded with a set of inertial measurement units. AG decreased the maximum flexion angle (MAX) of knees and hips as well as the range of motion (ROM), both at 1 and 1.25 g. Minor adaptation was observed between the first and the last repetition performed in AG. AG affects the ability to FS in naïve participants by reducing MAX, MIN and ROM of the knees and hip.

Development of a brief core set for knee dysfunction based on the International Classification of Functioning, Disability and Health: assessing construct validity and measurement potential.

BACKGROUND: The comprehensive core set for knee dysfunction was developed to classify the functioning of people with any knee dysfunction. To be used as a clinical instrument to measure the functioning of people with knee dysfunction, the construct validity of the core set still needs to be assessed. The purpose of this study was to analyze the construct validity of the comprehensive core set for knee dysfunction as an instrument to measure functioning. METHODS: A cross-sectional study with 200 participants with knee dysfunction with or without clinical diagnosis of knee pathology, with or without complaint of pain, with or without instability, and/or with or without knee movement restriction of any type. Participants were assessed using the comprehensive core set for knee dysfunction with 25 categories, the subjective form from the International Knee Documentation Committee scale, and measures of self-perceived general health and functioning. The construct validity of the core set was assessed by Rasch analysis, and the external construct validity was assessed by correlation between the score of the brief core set for knee dysfunction with the subjective form from the International Knee Documentation Committee scale, and scores of self-perception of health and functioning. RESULTS: Twelve categories were consistent with a unidimensional construct, with no difference in the response pattern for age, sex, educational level, and time of complaint. These categories were included in the brief core set for knee dysfunction. The mean score of the brief core set was 37 ± 21 points, a value classified as moderate impairment regarding functioning. Correlations with the subjective form from the International Knee Documentation Committee scale and scores of self-perception were adequate (p < 0.01; r > 0.5). CONCLUSION: The brief core set for knee dysfunction, a set with 12 categories, can be used as a clinical instrument to measure and score the functioning of people with knee dysfunction, aged between 18 and 89 years, with adequate construct validity.

Associations amongst dynamic knee stiffness during gait, quadriceps stiffness, and the incidence of knee osteoarthritis over 24 months: a cohort study with a mediation analysis.

BACKGROUND: Decreased strength and increased stiffness of the quadriceps have been associated with a higher risk of developing knee osteoarthritis (OA) in elders. Dynamic joint stiffness (DJS) represents collective resistance from active and passive knee structures for dynamic knee motions. Elevated sagittal knee DJS has been associated with worsening of cartilage loss in knee OA patients. Altered quadriceps properties may affect DJS, which could be a mediator for associations between quadriceps properties and knee OA. Hence, this study aimed to examine whether DJS and quadriceps properties would be associated with the development of clinical knee OA over 24 months, and to explore the mediation role of DJS in associations between quadriceps properties and knee OA. METHODS: This was a prospective cohort study with 162 healthy community-dwelling elders. Gait analysis was conducted to compute DJS during the loading response phase. Quadriceps strength and stiffness were evaluated using a Cybex dynamometer and shear-wave ultrasound elastography, respectively. Knee OA was defined based on clinical criteria 24 months later. Logistic regression with generalized estimating equations was used to examine the association between quadriceps properties and DJS and incident knee OA. Mediation analysis was performed to explore the mediation role of DJS in associations between quadriceps properties and the incidence of knee OA. RESULTS: A total of 125 participants (65.6 ± 4.0 years, 58.4% females) completed the 24-month follow-up, with 36 out of 250 knees identified as clinical knee OA. Higher DJS (OR = 1.86, 95%CI: 1.33-2.62), lower quadriceps strength (1.85, 1.05-3.23), and greater quadriceps stiffness (1.56, 1.10-2.21) were significantly associated with a higher risk of clinical knee OA. Mediation analysis showed that the DJS was not a significant mediator for the associations between quadriceps properties and knee OA. CONCLUSIONS: Higher sagittal knee dynamic joint stiffness, lower quadriceps strength, and greater quadriceps stiffness are potential risk factors for developing clinical knee OA in asymptomatic elders. Associations between quadriceps properties and knee OA may not be mediated by dynamic joint stiffness. Interventions for reducing increased passive properties of the quadriceps and knee joint stiffness may be beneficial for maintaining healthy knees in the aging population.

Effects of IL-6, JAK, TNF inhibitors, and CTLA4-Ig on knee symptoms in patients with rheumatoid arthritis.

This study aims to identify factors influencing the alleviation of knee joint symptoms in patients with rheumatoid arthritis treated with biologic or target synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). Among 2321 patients who started b/tsDMARDs between 2010 and 2023, we focused on 295 patients who had knee swelling or tenderness at the initiation of b/tsDMARDs and continued b/tsDMARDs at least 3 months, with recorded knee symptoms 6 months later. Symptom relief after 6 months was 78.2% for interleukin 6 (IL-6) inhibitors, 68.6% for Janus kinase (JAK) inhibitors, 65.8% for tumor necrosis factor (TNF) inhibitors, and 57.6% for cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig). The initial use of b/tsDMARDs and the use of IL-6 inhibitors in comparison to CTLA4-Ig emerged as a significant factor associated with the improvement of knee joint symptoms. Among 141 patients who underwent knee radiography at baseline and two years later, the deterioration in knee joint radiographs was 7.7% for IL-6 inhibitors, 6.3% for JAK inhibitors, 21.9% for TNF inhibitors, and 25.9% for CTLA4-Ig. The use of IL-6 inhibitors was a significant factor associated with the improvement of knee joint symptoms and the inhibition of joint destruction compared to CTLA4-Ig.

Advantages of cone beam computed tomography for evaluation of subchondral insufficiency fractures of the knee compared to MRI.

To determine the diagnostic yield of cone beam computed tomography (CBCT) compared with 3 T magnetic resonance imaging (MRI) for the evaluation of subchondral insufficiency fractures of the knee. Consecutive patients with subchondral insufficiency fractures of the knee examined by 3 T MRI and CBCT of the femoral condyles were reviewed. Two experienced raters graded the lesion severity on 3 T MRI and CBCT images: grade 1: no signs of a subchondral bone lesion; grade 2: subchondral trabecular fracture or cystic changes, but without infraction of the subchondral bone plate; grade 3: collapse of the subchondral bone plate. Ratings were repeated after six weeks to determine reliability. In addition, the bone lesion size was measured as elliptical area (mm2) and compared between CBCT and T1-weighted MRI sequences. Among 30 patients included (43.3% women; mean age: 60.9 ± 12.8 years; body mass index (BMI) 29.0 ± 12.8 kg/m2), the medial femoral condyle was affected in 21/30 patients (70%). The grading of subchondral lesions between MRI and CBCT did not match in 12 cases (40%). Based on MRI images, an underestimation (i.e., undergrading) compared with CBCT was observed in nine cases (30%), whereas overgrading occurred in three cases (10%). Compared to CBCT, routine T1-weighted 3 T sequences significantly overestimated osseus defect zones in sagittal (84.7 ± 68.9 mm2 vs. 35.9 ± 38.2 mm2, p < 0.01, Cohen's d = 1.14) and coronal orientation (53.1 ± 24.0 mm2 vs. 22.0 ± 15.2 mm2, p < 0.01, Cohen's d = 1.23). The reproducibility of the grading determined by intra- and inter-rater agreement was very high in MRI (intra-class correlation coefficient (ICC) 0.78 and 0.90, respectively) and CBCT (ICC 0.96 and 0.96, respectively). In patients with subchondral insufficiency fractures of the knee, the use of CBCT revealed discrepancies in lesion grading compared with MRI. These findings are clinically relevant, as precise determination of subchondral bone plate integrity may influence the decision about conservative or surgical treatment. CBCT represents our imaging modality of choice for grading the lesion and assessing subchondral bone plate integrity. MRI remains the gold standard modality to detect especially early stages.

Photobiomodulation therapy for chronic knee pain in obese patients in pre-rehabilitation for bariatric surgery: randomised, placebo-controlled, double-blinded, clinical trial protocol.

INTRODUCTION: Obesity has become a worldwide public health problem and is directly linked to loss of quality of life, complications and comorbidities. One of them is chronic pain, especially in the knees, which increases significantly and proportionally with weight gain. In patients with severe obesity, with indication for bariatric surgery, the presence of chronic pain disables and often prevents their participation in a pre-surgical rehabilitation programme. As an analgesic therapy, photobiomodulation (PBM) has been studied with safety, efficacy, well-tolerated used and low costs. Thus, this study aims to evaluate the use of PBM for the treatment of chronic knee pain in obese patients undergoing a pre-surgical rehabilitation programme for bariatric surgery. METHODS AND ANALYSES: This is a double-blinded, randomised, placebo-controlled clinical, superiority, trial protocol. The PBM will be applied in bilateral knees and lumbar paraspinal points levels referring to the roots of innervation of the knee. The outcomes evaluated will be pain intensity, functionality, quality of life and clinical signs of neurological sensitization of chronic knee pain pathways. ETHICS AND DISSEMINATION: This protocol has already been approved by the Comitê de Ética em Pesquisa do Hospital das Clínicas da Universidade Federal de Goiás/EBSERH-Ethics Committee and it is following SPIRIT guidelines. The results will be statistically analysed and subsequently published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: Clinical Trials Platform (https://clinicaltrials.gov/) with the number NCT05816798.

The effect of including a mobile arch, toe joint, and joint coupling on predictive neuromuscular simulations of human walking.

Predictive neuromuscular simulations are a powerful tool for studying the biomechanics of human walking, and deriving design criteria for technical devices like prostheses or biorobots. Good agreement between simulation and human data is essential for transferability to the real world. The human foot is often modeled with a single rigid element, but knowledge of how the foot model affects gait prediction is limited. Standardized procedures for selecting appropriate foot models are lacking. We performed 2D predictive neuromuscular simulations with six different foot models of increasing complexity to answer two questions: What is the effect of a mobile arch, a toe joint, and the coupling of toe and arch motion through the plantar fascia on gait prediction? and How much of the foot's anatomy do we need to model to predict sagittal plane walking kinematics and kinetics in good agreement with human data? We found that the foot model had a significant impact on ankle kinematics during terminal stance, push-off, and toe and arch kinematics. When focusing only on hip and knee kinematics, rigid foot models are sufficient. We hope our findings will help guide the community in modeling the human foot according to specific research goals and improve neuromuscular simulation accuracy.

Moving in pain - A preliminary study evaluating the immediate effects of experimental knee pain on locomotor biomechanics.

Pain changes how we move, but it is often confounded by other factors due to disease or injury. Experimental pain offers an opportunity to isolate the independent effect of pain on movement. We used cutaneous electrical stimulation to induce experimental knee pain during locomotion to study the short-term motor adaptions to pain. While other models of experimental pain have been used in locomotion, they lack the ability to modulate pain in real-time. Twelve healthy adults completed the single data collection session where they experienced six pain intensity conditions (0.5, 1, 2, 3, 4, 5 out of 10) and two pain delivery modes (tonic and phasic). Electrodes were placed over the lateral infrapatellar fat pad and medial tibial condyle to deliver the 10 Hz pure sinusoid via a constant current electrical stimulator. Pain intensity was calibrated prior to each walking bout based on the target intensity and was recorded using an 11-point numerical rating scale. Knee joint angles and moments were recorded over the walking bouts and summarized in waveform and discrete outcomes to be compared with baseline walking. Knee joint angles changed during the swing phase of gait, with higher pain intensities resulting in greater knee flexion angles. Minimal changes in joint moments were observed but there was a consistent pattern of decreasing joint stiffness with increasing pain intensity. Habituation was limited across the 30-90 second walking bouts and the electrical current needed to deliver the target pain intensities showed a positive linear relationship. Experimental knee pain shows subtle biomechanical changes and favourable habituation patterns over short walking bouts. Further exploration of this model is needed in real-world walking conditions and over longer timeframes to quantify motor adaptations.

Research priorities of members of the British Association for Surgery of the Knee.

Aims: This study aims to identify the top unanswered research priorities in the field of knee surgery using consensus-based methodology. Methods: Initial research questions were generated using an online survey sent to all 680 members of the British Association for Surgery of the Knee (BASK). Duplicates were removed and a longlist was generated from this scoping exercise by a panel of 13 experts from across the UK who provided oversight of the process. A modified Delphi process was used to refine the questions and determine a final list. To rank the final list of questions, each question was scored between one (low importance) and ten (high importance) in order to produce the final list. Results: This consensus exercise took place between December 2020 and April 2022. A total of 286 clinicians from the BASK membership provided input for the initial scoping exercise, which generated a list of 105 distinct research questions. Following review and prioritization, a longlist of 51 questions was sent out for two rounds of the Delphi process. A total of 42 clinicians responded to the first round and 24 responded to the second round. A final list of 24 research questions was then ranked by 36 clinicians. The topics included arthroplasty, infection, meniscus, osteotomy, patellofemoral, cartilage, and ligament pathologies. The management of early osteoarthritis was the highest-ranking question. Conclusion: A Delphi exercise involving the BASK membership has identified the future research priorities in knee surgery. This list of questions will allow clinicians, researchers, and funders to collaborate in order to deliver high-quality research in knee surgery and further advance the care provided to patients with knee pathology.

Identifying significant structural factors associated with knee pain severity in patients with osteoarthritis using machine learning.

Our main objective was to use machine learning methods to identify significant structural factors associated with pain severity in knee osteoarthritis patients. Additionally, we assessed the potential of various classes of imaging data using machine learning techniques to gauge knee pain severity. The data of semi-quantitative assessments of knee radiographs, semi-quantitative assessments of knee magnetic resonance imaging (MRI), and MRI images from 567 individuals in the Osteoarthritis Initiative (OAI) were utilized to train a series of machine learning models. Models were constructed using five machine learning methods: random forests (RF), support vector machines (SVM), logistic regression (LR), decision tree (DT), and Bayesian (Bayes). Employing tenfold cross-validation, we selected the best-performing models based on the area under the curve (AUC). The study results indicate no significant difference in performance among models using different imaging data. Subsequently, we employed a convolutional neural network (CNN) to extract features from magnetic resonance imaging (MRI), and class activation mapping (CAM) was utilized to generate saliency maps, highlighting regions associated with knee pain severity. A radiologist reviewed the images, identifying specific lesions colocalized with the CAM. The review of 421 knees revealed that effusion/synovitis (30.9%) and cartilage loss (30.6%) were the most frequent abnormalities associated with pain severity. Our study suggests cartilage loss and synovitis/effusion lesions as significant structural factors affecting pain severity in patients with knee osteoarthritis. Furthermore, our study highlights the potential of machine learning for assessing knee pain severity using radiographs.

Is single-stage bilateral medial opening wedge high tibial osteotomy advisable?

PURPOSE: To validate the safety and clinical results of single-stage bilateral versus unilateral medial opening wedge high tibial osteotomy (HTO). METHODS: A propensity-matched cohort study was performed from March 2020 to March 2021 in our medical center. Data were prospectively collected. Including 34 patients who underwent single-stage bilateral medial opening HTO(SSBHTO), and 68 cases in the unilateral group. Propensity-matched ration was 2:1 based on age, sex, and body mass index using R software. Comparisons of the length of hospital stay, operative time, blood loss, postoperative adverse events, 90-day readmission rate, conversion to TKA rate, self-reported VAS and WOMAC scores were made to investigate the safety and clinical results of bilateral HTO. RESULTS: The mean length of hospital stay was 7.36 ± 2.23 days for SSBHTO and 7 days (IQR, 3 days; range, 4 to 23 days) for the unilateral group (P = 0.219). The mean operative time was 144 ± 47 min for bilateral HTO and 105(37.5) mins for a unilateral OWHTO (P < 0.001). The mean blood loss was 150(100) ml for SSBHTO and 100(50) ml for unilateral OWHTO (P < 0.001). There were no significant difference of the adverse events and 90-day readmission rate between two groups. No failed HTO or conversion to knee arthroplasty were observed at the end of follow-up. VAS, pain, stiffness, and functional scores of the WOMAC scale were essentially comparable of two groups one year after surgery (P > 0.05). CONCLUSIONS: A single-stage bilateral medial opening wedge high tibial osteotomy is advisable for patients with knee osteoarthritis. Patients benefit from avoiding secondary anesthesia, postoperative complications, and substantial cost savings. LEVEL OF EVIDENCE: Therapeutic Level III.

Clinical and imaging findings associated with preservation of knee joint health over 8 years in individuals aged 65 and over: data from the OAI.

OBJECTIVE: While risk factors for osteoarthritis (OA) are well known, it is not well understood why certain individuals maintain high mobility and joint health throughout their life while others demonstrate OA at older ages. The purpose of this study was to assess which demographic, clinical and MRI quantitative and semi-quantitative factors are associated with preserving healthy knees in older individuals. METHODS: This study analyzed data from the OA Initiative (OAI) cohort of individuals at the age of 65 years or above. Participants without OA at baseline (BL) (Kellgren-Lawrence (KL) ≤ 1) were followed and classified as incident cases (KL ≥ 2 during follow-up; n = 115) and as non-incident (KL ≤ 1 over 96-month; n = 391). Associations between the predictor-variables sex, age, BMI, race, clinical scoring systems, T2 relaxation times and Whole-Organ Magnetic Resonance Imaging-Score (WORMS) readings at BL and the preservation of healthy knees (KL ≤ 1) during a 96-month follow-up period were assessed using logistic regression models. RESULTS: Obesity and presence of pain showed a significant inverse association with maintaining radiographically normal joints in patients aged 65 and above. T2 relaxation times of the lateral femur and tibia as well as the medial femur were also significantly associated with maintaining radiographically normal knee joints. Additionally, absence of lesions of the lateral meniscus and absence of cartilage lesions in the medial and patellofemoral compartments were significantly associated with maintaining healthy knee joints. CONCLUSION: Overall, this study provides protective clinical parameters as well as quantitative and semi-quantitative MR-imaging parameters associated with maintaining radiographically normal knee joints in an older population over 8 years.

Efficacy of home-based exercise in the treatment of pain and disability at the hip and knee in patients with osteoarthritis: a systematic review and meta-analysis.

BACKGROUND: An increasing body of evidence suggests that home-based exercise (HBE) therapy has significant therapeutic effects on knee osteoarthritis (KOA) and hip osteoarthritis (HipOA), and it has advantages such as cost savings, strong operability, and good compliance compared with hospitalization and exercise courses. OBJECTIVE: To evaluate the efficacy of HBE in the treatment of KOA and HipOA. METHODS: A systematic search was conducted in PubMed, Cochrane, Web of Science, and Embase to collect randomized controlled trials. The retrieval time was from database establishment until March 6, 2024. Stata 15.1 software was used for data analysis. RESULTS: A total of 16 randomized controlled trials involving 3,015participants were included, with 1,519 participants in the intervention group and 1,496 in the control group. The meta-analysis showed that, compared to the control group, HBE can significantly improve pain [SMD=-0.38, 95% CI (-0.58, -0.18); P = 0.001], joint function [SMD=-0.60, 95% CI (-1.01, -0.19); P = 0.004], balance ability [SMD=-0.67, 95% CI (-1.00, -0.34); P = 0.001], mobility (ADL) [SMD = 0.51, 95% CI (0.19, 0.82); P = 0.002] in patients with KOA and HipOA. There is no statistical difference in the improvement of joint stiffness [WMD = -0.80, 95% CI (-1.61, 0.01); P = 0.052]. In addition, subgroup analysis showed that HBE significantly improved pain, joint function, and balance ability in KOA patients compared with the control group. HipOA patients showed significant improvement in pain and joint function; However, HBE only improved activity ability in patients with comorbidities of KOA and HipOA. CONCLUSION: HBE can effectively alleviate pain, improve joint function, and enhance physical function in patients with KOA and HipOA. However, more high-quality randomized controlled trials (RCTs) with large sample sizes and long-term interventions are needed to validate the efficacy of HBE due to limitations in the methodology and consistency of indicator outcomes in the included RCTs. REGISTRATION NUMBER: We've registered with PROSPERO, and the number is CRD42023443085.

Double-Bundle Medial Collateral Ligament Reconstruction Improves Anteromedial Rotatory Instability.

BACKGROUND: New techniques have been proposed to better address anteromedial rotatory instability in a medial collateral ligament (MCL)-injured knee that require an extra graft and more surgical implants, which might not be feasible in every clinical setting. PURPOSE: To investigate if improved resistance to anteromedial rotatory instability can be achieved by using a single-graft, double-bundle (DB) MCL reconstruction with a proximal fixation more anteriorly on the tibia, in comparison with the gold standard single-bundle (SB) MCL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator in intact knee, superficial MCL/deep MCL-deficient, and reconstruction states. Three different reconstructions were tested: DB MCL no proximal tibial fixation and DB and SB MCL reconstruction with proximal tibial fixation. Knee kinematics were recorded at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8 N·m of valgus rotation (VR), 5 N·m of external tibial rotation, 5 N·m of internal tibial rotation, combined 89 N of anterior tibial translation and 5 N·m of external rotation for anteromedial rotation (AMR) and anteromedial translation (AMT). The differences between each state for every measurement were analyzed with VR and AMR/AMT as primary outcomes. RESULTS: Cutting the superficial MCL/deep MCL increased VR and AMR/AMT in all knee positions except at 90° for VR (P < .05). All reconstructions restored VR to the intact state except at 90° of knee flexion (P < .05). The DB MCL no proximal tibial fixation reconstruction could not restore intact AMR/AMT kinematics in any knee position (P < .05). Adding an anterior-based proximal tibial fixation restored intact AMR/AMT kinematics at ≥30° of knee flexion except at 90° for AMT (P < .05). The SB MCL reconstruction could not restore intact AMR/AMT kinematics at 0° and 90° of knee flexion (P < .05). CONCLUSION: In this in vitro cadaveric study, a DB MCL reconstruction with anteriorly placed proximal tibial fixation was able to control AMR and AMT better than the gold standard SB MCL reconstruction. CLINICAL RELEVANCE: In patients with anteromedial rotatory instability and valgus instability, a DB MCL reconstruction may be superior to the SB MCL reconstruction, without causing extra surgical morbidity or additional costs.

[Early-term effectiveness comparison of suture hook suture via double posteromedial approaches and Fast-Fix total internal suture in treatment of Ramp lesions].

Objective: To compare the short-term effectiveness of suture hook suture via double posteromedial approaches and Fast-Fix total internal suture in treatment of Ramp lesions. Methods: A clinical data of 56 patients with anterior cruciate ligament rupture combined with Ramp lesions, who met the selection criteria and admitted between December 2021 and February 2023, was retrospectively analyzed. The Ramp lesions were sutured using suture hook via double posteromedial approaches under arthroscopy in 28 cases (group A) and treated with Fast-Fix total internal suture under arthroscopy in 28 cases (group B). There was no significant difference in age, gender, cause of injury, type of injury, time from injury to operation, side of injury, body mass index, and preoperative Lysholm score, visual analogue scale (VAS) score, and Tegner score between the two groups ( P>0.05). The patients were followed up regularly after operation, and the clinical and imaging healing of the Ramp lesion was evaluated according to the Barrett clinical healing standard and the MRI evaluation standard. Lysholm score, VAS score, and Tegner score were used to evaluate the function and pain degree of knee joint, and the results were compared with those before operation. Results: The incisions of the two groups healed by first intention. All patients were followed up 12-18 months (mean, 14.9 months). Postoperative McMurray tests were negative in both groups. The clinical healing rates of group A and group B were 71.4% (20/28) and 64.3% (18/28) at 6 months after operation, and 92.9% (26/28) and 82.1% (23/28) at 12 months after operation, respectively. The differences between the two groups was not significant ( χ 2=0.327, P=0.567; χ 2=0.469, P=0.225). There was no significant difference in Lysholm score, VAS score, and Tegner score between the two groups at each time point after operation ( P>0.05). The postoperative scores in the two groups significantly improved when compared with those before operation, and the scores at 12 months after operation further improved when compared with those at 6 months after operation, showing significant differences between the different time points in the two groups ( P<0.05). At last follow-up, MRI examination of the knee joint showed that there were 26 (92.9%), 2 (7.1%), and 0 (0) cases of complete healing, partial healing, and nonunion in the Ramp lesion of group A, and 25 (89.3%), 1 (3.6%), and 2 (7.1%) cases in group B, respectively. There was no significant difference between the two groups ( Z=-0.530, P=0.596). Conclusion: Suture hook suture via double posteromedial approaches and Fast-Fix total internal suture under arthroscopy are safe and reliable in the treatment of Ramp lesion, and the knee joint function significantly improves after operation.

[Comparison of effectiveness of tibial intramedullary nailing fixation via suprapatellar approach and medial parapatellar approach in treatment of multiple tibial fractures].

Objective: To compare the effectiveness of intramedullary nailing fixation via suprapatellar approach and medial parapatellar approach in semi-extended position in the treatment of multiple tibial fractures. Methods: The clinical data of 43 patients with multiple tibial fractures treated with intramedullary nailing fixation between July 2018 and December 2022 were retrospectively analyzed, including 23 patients treated with suprapatellar approach in semi-extended position (group A) and 20 patients with medial parapatellar approach in semi-extended position (group B). There was no significant difference in gender, age, cause of injury, time from injury to operation, AO/Orthopaedic Trauma Association (AO/OTA) classification, preoperative visual analogue scale (VAS) score, and range of motion (ROM) of the knee joint between the two groups ( P>0.05). The operation time, intraoperative blood loss, incision length, intraoperative fluoroscopy frequency, and fracture healing time were recorded and compared. The VAS score and ROM of the knee joint were analyzed at 4, 8, and 12 weeks after operation, and the incidence of postoperative complications was observed; knee function was evaluated by Lysholm score at last follow-up. Results: The operations were successfully completed in both groups, and there was no complication such as nerve and blood vessel injury during operation, and all incisions healed by first intention. There was no significant difference in operation time, intraoperative blood loss, and intraoperative fluoroscopy frequency between the two groups ( P>0.05), but the incision length in group B was significantly longer than that in group A ( P<0.05). Patients in both groups were followed up 12-30 months, with an average of 21.1 months. The VAS score decreased and ROM increased gradually in both groups with time after operation, showing significant differences between different time points ( P<0.05). The VAS score of group B was significantly lower than that of group A at 4 and 8 weeks after operation ( P<0.05); there was no significant difference in VAS score and ROM between the two groups at other time points ( P>0.05). There was no significant difference in fracture healing time between the two groups ( P>0.05). During the follow-up, there was no complication such as internal fixator loosening, breakage, and loss of fracture reduction. At last follow-up, the Lysholm score in group B was significantly better than that in group A ( P<0.05). Conclusion: Both the suprapatellar approach and the medial parapatellar approach in semi-extended position can achieve satisfactory results in the treatment of multiple tibial fractures. The medial parapatellar approach has lower symptoms of early knee pain and better long-term function.

[Finite element analysis of the impact of bone mass and volume of low-density area under tibial plateau on lower limb alignment].

Objective: To investigate the impact of the bone mass and volume of the low-density area under the tibial plateau on the lower limb force line by finite element analysis, offering mechanical evidence for preventing internal displacement of the lower limb force line in conjunction with knee varus in patients with knee osteoarthritis (KOA) and reducing bone mass under the tibial plateau. Methods: A healthy adult was selected as the study subject, and X-ray film and CT imaging data were acquired. Mimics 21.0 software was utilized to reconstruct the complete knee joint model and three models representing low-density areas under the tibial plateau with equal volume but varying shapes. These models were then imported into Solidworks 2023 software for assembly and verification. Five KOA finite element models with 22%, 33%, 44%, 55%, and 66% bone mass reduction in the low-density area under tibial plateau and 5 KOA finite element models with 81%, 90%, 100%, 110%, and 121% times of the low-density area model with 66% bone mass loss were constructed, respectively. Under physiological loading conditions of the human lower limb, the distal ends of the tibia and fibula were fully immobilized. An axial compressive load of 1 860 N, following the lower limb force line, was applied to the primary load-bearing area on the femoral head surface. The maximum stress within the tibial plateau, as well as the maximum displacements of the tibial cortical bone and tibial subchondral bone, were calculated and analyzed using the finite element analysis software Abaqus 2022. Subsequently, predictions regarding the alteration of the lower limb force line were made based on the analysis results. Results: The constructed KOA model accorded with the normal anatomical structure of lower limbs. Under the same boundary conditions and the same load, the maximum stress of the medial tibial plateau, the maximum displacement of the tibial cortical bone and the maximum displacement of the cancellous bone increased along with the gradual decrease of bone mass in the low-density area under the tibial plateau and the gradual increase in the volume of the low-density area under tibial plateau, with significant differences ( P<0.05). Conclusion: The existence of a low-density area under tibial plateau suggests a heightened likelihood of knee varus and inward movement of the lower limb force line. Both the volume and reduction in bone mass of the low-density area serve as critical initiating factors. This information can provide valuable guidance to clinicians in proactively preventing knee varus and averting its occurrence.

The thickness change ratio and preservation ratio of the infrapatellar fat pad are related to anterior knee pain in patients following medial patellofemoral ligament reconstruction.

BACKGROUND: The infrapatellar fat pad (IPFP) lies extrasynovial and intracapsular, preserving the joint cavity and serving as a biochemical regulator of inflammatory reactions. However, there is a lack of research on the relationship between anterior knee pain (AKP) and the IPFP after medial patellofemoral ligament reconstruction (MPFLR). Pinpointing the source of pain enables clinicians to promptly manage and intervene, facilitating personalized rehabilitation and improving patient prognosis. METHODS: A total of 181 patients were included in the study. These patients were divided into the AKP group (n = 37) and the control group (n = 144). Clinical outcomes included three pain-related scores, Tegner activity score, patient satisfaction, etc. Imaging outcomes included the IPFP thickness, IPFP fibrosis, and the IPFP thickness change and preservation ratio. Multivariate analysis was used to determine the independent factors associated with AKP. Finally, the correlation between independent factors and three pain-related scores was analyzed to verify the results. RESULTS: The control group had better postoperative pain-related scores and Tegner activity score than the AKP group (P < 0.01). The AKP group had lower IPFP thickness change ratio and preservation ratio (P < 0.001), and smaller IPFP thickness (P < 0.05). The multivariate analysis revealed that the IPFP thickness change ratio [OR = 0.895, P < 0.001] and the IPFP preservation ratio [OR = 0.389, P < 0.001] were independent factors related to AKP, with a significant correlation between these factors and pain-related scores [|r| > 0.50, P < 0.01]. CONCLUSIONS: This study showed the lower IPFP change ratio and preservation ratio may be independent factors associated with AKP after MPFLR. Early detection and targeted intervention of the underlying pain sources can pave the way for tailored rehabilitation programs and improved surgical outcomes. LEVEL OF EVIDENCE LEVEL III.

Intra- and inter-operator reliability of measuring compressive stiffness of the patellar tendon in volleyball players using a handheld digital palpation device.

This observational study aimed to evaluate the intra- and inter-operator reliability of a digital palpation device in measuring compressive stiffness of the patellar tendon at different knee angles in talent and elite volleyball players. Second aim was to examine differences in reliability when measuring at different knee angles, between dominant and non-dominant knees, between sexes, and with age. Two operators measured stiffness at the midpoint of the patellar tendon in 45 Dutch volleyball players at 0°, 45° and 90° knee flexion, on both the dominant and non-dominant side. We found excellent intra-operator reliability (ICC>0.979). For inter-operator reliability, significant differences were found in stiffness measured between operators (p<0.007). The coefficient of variance significantly decreased with increasing knee flexion (2.27% at 0°, 1.65% at 45° and 1.20% at 90°, p<0.001). In conclusion, the device appeared to be reliable when measuring compressive stiffness of the patellar tendon in elite volleyball players, especially at 90° knee flexion. Inter-operator reliability appeared to be questionable. More standardized positioning and measurement protocols seem necessary.