Osteophyte formation, a key indicator of osteoarthritis (OA) severity, remains poorly understood in its relation to gut microbiota and metabolites in knee osteoarthritis (KOA). We conducted 16S rDNA sequencing and untargeted metabolomics on fecal and serum samples from 20 healthy volunteers, 80 KOA patients in Guangdong, and 100 in Inner Mongolia, respectively. Through bioinformatics analysis, we identified 3 genera and 5 serum metabolites associated with KOA osteophyte formation. Blautia abundance negatively correlated with meat, cheese, and bean consumption. The 5 serum metabolites negatively correlated with dairy, beef, cheese, sugar, and salt intake, yet positively with age and oil consumption. Higher Blautia levels in the gut may contribute to KOA osteophyte formation, with serum metabolites LTB4 and PGD2 potentially serving as biomarkers. KOA patients in Inner Mongolia exhibited lower Blautia levels and reduced expression of 5 serum metabolites, possibly due to cheese consumption habits, resulting in less osteophyte formation.
Objective: Patellofemoral kinematics and contact mechanics are important measurements for the assessment of patellofemoral joint (PFJ) problems. Simultaneously measuring PFJ contact pressures and kinematics is a challenging task. The purpose of this study was to simultaneously measure the kinematics and mean/peak contact pressures in the PFJs of cadaveric knees.Methods: This was a comparative study performed on fresh cadaveric knees. The kinematic data was acquired for nine cadaveric knees using an optical tracking system. Data about the contact pressure and contact area in the PFJ was obtained at knee flexion angles of 0°, 30°, 60°, 90°, and 120° using a pressure sensor. Intraclass correlation coefficients (ICCs) and minimal detectable differences (MDDs) of six degrees of freedom (6 DOF) in the PFJs were calculated. ICCs and the MDDs of contact pressure, peak pressure, and contact area in the PFJs were also analyzed. We also compared the kinematics of the cadaveric knees before and after the insertion of the pressure sensor.Results: All ICC values of 6 DOF in the PFJs were found to be greater than or equal to 0.924. Regarding medial–lateral rotation, the patellar showed a simplified movement pattern that demonstrated progressive lateral rotation of 4.8° ± 3.4° at 120° of knee flexion. While for patellar tilting, the patella showed medial tilting that peaked at 7.2 ± 2.5° at 30° of knee flexion. Whereas no significant differences in PFJ kinematics were found between with and without the placement of the pressure sensor at all knee flexions (P > 0.05). Most of the ICC values for contact pressure, peak contact pressure, and contact area ranged from 0.8 to 0.9. The MDDs for rotational displacement were 0.9° and 0.6 mm for translational displacement. No statistical differences in patellar kinematics were found before and after the insertion of the pressure sensor.Conclusions: The setup in the present study enables researchers to simultaneously and synchronously collect real‐time PFJ kinematics and tibiofemoral joint (TFJ) biomechanical kinematic data with high reliability. The low MDDs enabled the researchers to obtain an accurate interpretation of the kinematic and contact mechanics measurement using the experimental setting used in the present study.
Objective: Knee kinematic asymmetries after anterior cruciate ligament reconstruction (ACLR) are correlated with poor clinical outcomes, such as the progression of knee cartilage degenerations or reinjuries. Fast walking in patients with knee conditions may exacerbate knee kinematic asymmetries, but its impact on ACLR patients is uncertain. The aim of this study is to investigate if fast walking induces more knee kinematic asymmetries in unilateral ACLR patients.Methods: This cross‐sectional study enrolled 55 patients with unilateral ACLR from January 2020 to July 2022. There were 48 males and seven females with an average age of 30.6 ± 6.4 years. Knee kinematic data were collected at three walking speeds: self‐selected, fast (150% normal), and slow (50% normal). A 3D knee kinematic analysis system measured the data, and self‐reported outcomes assessed comfort levels during walking. We used SPM1D for two‐way repeated ANOVA and posthoc paired t‐tests to analyze kinematic differences in groups.Results: In fast walking, ACLR knees exhibited more transverse kinematic asymmetries than intact knees, including greater external rotation angle (1.8°, 38%–43%; gait cycle [GC], p < 0.05 & 1.8–2.7°, 50%–61% GC, p < 0.05) and increased proximal tibial translation (2.1–2.5 mm, 2%–6% GC, p < 0.05 & 2.5–3.2 mm, 92%–96% GC, p < 0.05). Additionally, ACLR knees showed greater posterior tibial translation than intact knees (3.6–3.7 mm, 7%–8% GC, p < 0.05) during fast walking. No posterior tibial translation asymmetries were observed in slow walking compared to normal walking levels. ACLR knees have the most comfortable feelings in slow walking speed, and the most uncomfortable feelings in fast walking speed levels (29%).Conclusions: Fast walking induces additional external tibial rotation and proximal and posterior tibial translation asymmetries in ACLR patients. This raises concerns about long‐term safety and health during fast walking. Fast walking, not self‐selected speed, is beneficial for identifying postoperative gait asymmetries in ACLR patients.
21 September 2022 in Frontiers in Bioengineering and Biotechnology
Whether load carriage leads to six-degrees-of-freedom (6DOF) knee kinematic alterations remains unclear. Exploring this mechanism may reveal meaningful knee kinematic information that can be used to improve load carriage conditions, the design of protective devices, and the knowledge of the effects of load carriage on knees. We recruited 44 subjects to explore kinematic alterations from an unloaded state to 60% bodyweight (BW) load carriage. A three-dimensional gait analysis system was used to collect the knee kinematic data. One-way repeated analysis of variance (ANOVA) was used to explore the effects of load levels on knee kinematics. The effects of increasing load levels on knee kinematics were smooth with decreased or increased trends. We found that knees significantly exhibited increased lateral tibial translation (up to 1.2 mm), knee flexion angle (up to 1.4°), internal tibial rotation (up to 1.3°), and tibial proximal translation (up to 1.0 mm) when they went from an unloaded state to 60%BW load carriage during the stance phase (p < 0.05). Significant small knee adduction/abduction angle and posterior tibial translation alterations (<1°/mm) were also identified (p < 0.05). Load carriage can cause significant 6DOF knee kinematic alterations. The results showed that knee kinematic environments are challenging during increased load. Our results contain kinematic information that could be helpful for knee-protection-related activities, such as target muscle training to reduce abnormal knee kinematics and knee brace design.
23 August 2022 in Frontiers in Bioengineering and Biotechnology
Anterior cruciate ligament deficiency (ACLD) patients tend to walk slowly but try to catch up with the speed level of healthy subjects daily. Exploring the effects of the walking speed level of healthy subjects on the ACLD patients’ knee kinematics is important to improving non-operative treatments and delaying the progression of posttraumatic knee osteoarthritis. This study aimed to explore whether healthy controls’ walking speed level leads to additional knee kinematic asymmetries in patients with ACLD. 27 ACLD patients and 29 healthy controls were recruited for the study. The ACLD patients walked at two levels of walking speed, including self-selected and healthy controls’ walking speed levels. A three-dimensional gait analysis system was used to collect their knee kinematic data. ACLD patients exhibited more kinematic asymmetries when walking at healthy controls’ walking speed level than at their self-selected speeds. The kinematic asymmetries included increased posterior tibial translation (4.6 mm) and anteroposterior tibial ROM (3.9 mm), abduction angle (1.5°), and distal tibial translation (3.2 mm) asymmetries (p < 0.05). Our findings are meaningful for developing non-operative treatment strategies for patients with ACLD. To get fewer knee kinematic asymmetries, self-selected walking speed could be suggested for patients with ACLD daily rather than the speed levels of healthy subjects.
Objective: To investigate the clinical effects of microwave ablation (MWA) in addition to open surgery for the treatment of lung cancer‐derived thoracolumbar metastases.Methods: This was a single‐institution, retrospective, cohort study. From January 2019 to December 2020, a total of 47 patients with lung cancer‐derived thoracolumbar metastases underwent posterior spinal canal decompression and fixation surgery in our hospital. Two independent surgical teams treated these patients. One group underwent open surgery combined with MWA therapy, while the other had open surgery only (control). The pre‐ and post‐operative visual analog scale (VAS) scores and the overall survival (OS) were compared between the MWA and control groups. The Frankel Grade classification was applied for the evaluation of the post‐surgical spinal cord function. Improvement was defined as an increase of at least one rank from the pre‐operative scores. Each patient was evaluated pre‐ and post‐operatively at 48 h, 1 month, and 3‐month intervals. Data on surgical‐related complications were recorded.Results: Thirty men and 17 women were included, with an average age of 57.9 ± 11.4 years (range, 26–81 years). Twenty‐eight patients underwent MWA and were in the MWA group, and 19 patients were included in the control group. Post‐operatively all patients were followed up regularly; the median follow‐up time was 12 months (range, 3–24 months), and their median OS was 14 months. Patients in the MWA group had a lower VAS score than those in the control group at the 48‐h (1.75 ± 1.01 vs 2.47 ± 0.96, P = 0.01) and 1‐month (1.79 ± 0.92 vs 2.53 ± 1.35, P = 0.048) check‐ups. At the 3‐month evaluation, the VAS score differences between the two groups were not significant (P = 0.133). After surgery, spinal cord function improvement was not significantly different between the MWA and control groups (P = 0.515). MWA therapy combined with open surgery was not associated with increased OS compared with the control group (P = 0.492).Conclusion: MWA can be an effective and safe pain‐relief method but may not extend the OS of patients with lung cancer.