Knee最新文献

Background: Existing knee osteoarthritis (KOA) severity classification methods typically rely on a combination of object detection algorithms and classification algorithms. However, this approach not only increases the computational burden and time costs but also reduces the efficiency of real-time diagnosis, which makes it difficult to meet the needs of practical applications. To address the performance limitations of KOA severity recognition models that operate without target detection algorithms, a deep transfer learning approach incorporating a novel activation function (AvRELU) was proposed. The goal was to improve classification performance, particularly for small sample datasets, while optimizing computational resources.

Methods: A dataset consisting of 3300 digital X-ray images of KOA patients was utilized. During model training and evaluation, five-fold cross-validation was used to assess robustness, and the dataset was divided into training, validation, and testing sets through a stratified sampling method at an 8:1:1 ratio. A transfer learning approach utilizing a pretrained Inception-v3 backbone was proposed, where Bayesian optimization automated both the fine-tuning process and downstream classifier construction. To improve the model performance, the activation function AvRELU was introduced in the network layer of the downstream model. Moreover, Kendall's tau-b correlation analysis was employed to evaluate the statistical significance of differences in the predicted Kellgren-Lawrence grades among the different methods.

Results: Using five-fold cross-validation, the proposed method achieved an average test set performance of 95% accuracy, 95% F1-score, and 93% kappa. These results demonstrated the superior performance of the method in KOA severity recognition.

Conclusions: The method proposed here not only significantly improves model performance on small-sample datasets but also maintains the model's lightweight and low-resource characteristics. Moreover, it achieves better performance in KOA severity recognition than most existing methods.

Background: Individuals with patellofemoral pain (PFP) commonly exhibit muscle weakness; however, the relationship between muscle strength deficits and other factors in this population remains unclear. The present systematic review aimed to identify factors correlated with muscle strength capacity in individuals with PFP.

Method: A systematic search was conducted in Medline, Embase, CINAHL, SPORTDiscus, and Web of Science from their inception to September 2025. Correlational studies that included individuals with PFP and reported quantitative measures of muscle strength correlated with other quantitative variables were eligible for inclusion.

Results: Out of 9370 records screened, 57 studies met the inclusion criteria, and 37 were included in the meta-analyses. The findings indicated that knee extensor strength is trivially to moderately correlated with functionality, pain, pain duration, and kinesiophobia; knee flexor strength is weakly to moderately correlated with functionality and pain; hip abductor strength is trivially to moderately correlated with function, hip frontal and transverse plane movements; hip extensor strength is weakly correlated with function; hip external rotation strength is weakly correlated with function; hip posterolateral strength is moderately correlated with function; and trunk lateral flexion strength is weakly correlated with knee frontal plane movement.

Conclusion: Despite the generally weak correlations observed, muscle strength capacity in individuals with PFP presents significant associations with key factors such as pain, function, kinesiophobia, and lower limb movement patterns.

Background: This study aimed to assess long-term survival and clinical outcomes of a posterior-stabilized total knee arthroplasty (TKA) using an Oxidized Zirconium (OxZr) femoral component after a minimum 10-year follow-up.

Methods: A retrospective analysis was conducted on 183 TKAs in 180 patients treated with OxZr femoral component between January 2011 and December 2012. Patients had end-stage knee osteoarthritis and failed medical treatment. Exclusion criteria included the use of extension stems, bone reconstruction, or loss to follow-up. Mean follow-up was 10.39 ± 0.49 years. Primary endpoint was implant survival; secondary endpoints included functional and radiographic outcomes.

Results: Eleven revisions were performed, all due to aseptic loosening of the tibial component. The 10-year survival rate for aseptic loosening was 94% (95% CI: 90.6-97.5%), and overall survival was 89.1% (95% CI: 84.7-93.7%). Functional scores improved significantly: the IKS function score rose from 50.7 ± 11.5 to 83.2 ± 13.9, and the IKS knee score from 67.5 ± 8.3 to 88.9 ± 8.2 (both p < 0.001). Satisfaction was high, with 73.3% of patients reporting being satisfied or very satisfied. Radiolucent lines appeared in 36.6% of cases. Cement type and operative time were significant risk factors for tibial loosening.

Conclusion: The TKA with an OxZr femoral component showed good long-term survival and functional outcomes, though tibial loosening remains a concern, potentially linked to cement type.

Background: Kinematic alignment (KA) total knee arthroplasty (TKA) seeks to restore native limb and knee alignments regardless of the degree of preoperative deformity and/or flexion contracture. Hence, the thickness of each femoral resection should match the femoral component after adjusting for cartilage wear and sawblade kerf. Previously, the thickness of worn articular cartilage has been set at 2 mm. If the proportion of patients with thickness ≥3 mm is relatively large however, then adjusting resection thickness to reflect cartilage thickness is a refinement of interest. The objectives were to determine the proportion of patients undergoing KA TKA with cartilage thickness ≥3 mm in each resection.

Method: Using calibrated photographs, articular cartilage thickness was measured on 456 unworn resections (i.e. distal medial and lateral, posterior medial and lateral) from 201 patients undergoing KA TKA. The proportion of patients with cartilage thickness ≥3 mm was determined for each resection.

Results: The proportions of patients with cartilage thickness ≥3 mm were 29% and 34% for the distal medial and lateral resections, respectively, and 36% and 23% for the posterior medial and lateral resections, respectively.

Conclusion: The relatively large proportion of patients with cartilage thickness ≥3 mm motivates taking next steps to assess the clinical practicality of adjusting resection thickness to reflect cartilage thickness. One next step is to determine how accurately cartilage thicknesses of worn distal and posterior surfaces can be predicted by measuring thickness of the contralateral unworn distal surface.

Background: The morphometric relationship between the femoral condyle and lateral meniscus has not been quantitatively characterized. Subtle alterations in femoral geometry may modify load distribution and predispose to meniscal re-tear, yet no reproducible MRI index exists to quantify this phenomenon.

Purpose: To define and validate the Femoral Condylar Consumption Index (FCCI) as a geometric MRI parameter predictive of lateral meniscal lesion and re-tear.

Methods: A retrospective case-control MRI study was conducted including 120 knees: 60 with arthroscopically confirmed lateral meniscal tears (20 re-tears) and 60 controls. The FCCI was calculated as. FCCI=R₀-R₁R₀x100 where R₀ represents an internal reference radius derived from the medial femoral condyle, and R₁ the measured radius of the lateral condyle on sagittal MRI. Two blinded observers performed independent measurements. Interobserver reliability, receiver operating characteristic (ROC) analysis, and multivariate logistic regression were applied.

Results: The mean FCCI was significantly greater in the lesion group than in controls (12.8 ± 3.2% vs. 5.1 ± 2.0%, P < 0.001). An FCCI > 9% predicted meniscal tear with sensitivity 0.86 and specificity 0.82 (AUC = 0.89; 95% CI, 0.83-0.95). Recurrent tears exhibited higher values (15.6 ± 3.4%) than primary tears (11.9 ± 2.8%, P = 0.002). In multivariate analysis, FCCI > 9% remained an independent predictor (OR = 6.4; 95% CI, 2.3-10.8; P < 0.001). Reliability was excellent (ICC_inter = 0.91; ICC_intra = 0.88).

Conclusion: The FCCI is a novel, reproducible geometric parameter that quantifies posterior femoral condylar flattening and predicts both primary and recurrent lateral meniscal tears. Incorporation into preoperative MRI assessment may assist in risk stratification and surgical planning. Before FCCI can be applied prognostically, prospective validation is required to establish temporal precedence and causal relevance.

Background: Meniscal tears are common intra-articular knee injuries that cause pain, swelling, and impaired mobility. Although magnetic resonance imaging (MRI) remains the diagnostic gold standard, interest is increasing in hematological and inflammatory indices as potential adjunctive biomarkers reflecting inflammatory activity.

Purpose: To examine the relationship between meniscal tears and systemic inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), mean platelet volume (MPV), neutrophil-to-platelet ratio (NPR), and systemic immune-inflammation index (SII), and to assess their diagnostic performance.

Methods: A retrospective case-control study was conducted at Tepecik Training and Research Hospital, comprising 286 participants 143 patients with MRI-confirmed meniscal tears and 143 age- and sex-matched healthy controls. Hematological indices were derived from complete blood counts. Between-group comparisons were performed using the Mann-Whitney U and chi-square tests, correlations were evaluated by Spearman's analysis, and receiver operating characteristic (ROC) curves assessed discriminative ability.

Results: Meniscal tear patients showed significantly lower MPV (p < 0.001) and NLR (p < 0.001), but higher NPR (p = 0.023) compared to controls. No significant difference was observed for SII (p = 0.740). Smoking was associated with higher MPV-to-lymphocyte ratio (p = 0.007). ROC analysis indicated weak discrimination for NPR (AUC = 0.578, p = 0.023) and poor performance for SII (AUC = 0.511).

Conclusion: Inflammatory indices, particularly NPR, may reflect systemic inflammatory changes related to meniscal tears. While their diagnostic utility alone is limited, they may serve as supportive tools alongside imaging in evaluating meniscal pathology.

Purpose: Lower limb torsion affects the accuracy of knee coronal alignment measurements, which has an impact on the planning for surgical management of knee osteoarthritis (KOA). Current computed tomography (CT) scans for evaluating torsion are costly and cannot be performed for every case. This study aimed to investigate the relationship between distal and proximal tibio-fibular overlap ratio measured on long-limb radiographs with femoral and tibial torsion quantified by CT scan in an Asian population with KOA.

Methods: A retrospective analysis was performed on patients who were planned for robotic total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) between September 2018 and April 2024 in a single tertiary institution. Proximal and distal tibio-fibular overlap was defined as the longest overlapping length between the medial cortex of the fibula and the lateral cortex of the tibia, measured on weight-bearing long-leg radiographs. Femoral and tibial torsion were assessed on CT images using the Lee and bimalleolar method, respectively. Spearman's rank correlation coefficient was used to examine associations between the tibio-fibular overlap ratio and tibial and femoral torsion. Receiver operating characteristic (ROC) curve analysis was used to assess the ability of the overlap ratio to discriminate between increased and decreased torsion, with area under the curve (AUC), sensitivity, and specificity reported. Inter- and intra-observer reliability were assessed using intraclass correlation coefficients (ICCs) in a random sample of 30 patients.

Results: A total of 217 patients were included (74 males and 143 females; 66.3 ± 8.8 years old). The median tibio-fibular overlap ratio and femoral torsion was 0.9 (0.7-0.8) and 26.9° (-10.7° to 7°), respectively. The mean tibial torsion was 20.7° + 8.55°. Overall, a moderate positive Spearman correlation of tibio-fibular overlap ratio with tibial torsion (ρ = 0.54, P < 0.001) was observed. ROC analysis for tibio-fibular overlap ratio in predicting both decreased (AUC 0.91 ± 0.05; 95%, CI 0.81-0.99) and increased tibial torsion (AUC 0.77 ± 0.07; 95%, CI 0.64-0.90) was excellent and acceptable, respectively. For predicting low tibial torsion, the optimal cut-off was <0.5 (sensitivity 99%, specificity 82%). For predicting high tibial torsion, the optimal cutoff was >0.8 (sensitivity 76%, specificity 71%). Reliability analysis revealed excellent intra-observer and interobserver reliability.

Conclusion: This study suggests the utility of the tibio-fibular overlap ratio as a potential screening tool for underlying tibia torsional deformity. Further evaluation of tibial torsion is recommended for knees with tibio-fibular overlap ratio of <0.5 or >0.8.

Aim: To define the Patient-Acceptable Symptom State (PASS) in the Oxford Knee Score (OKS) following total knee arthroplasty (TKA) and identify independent preoperative factors associated with failure to achieve this threshold.

Methods: A retrospective cohort of 3304 patients undergoing primary TKA who completed preoperative and 6-month OKS was identified from an arthroplasty registry. The PASS was defined using receiver operating curve analysis, using patient satisfaction at 6 months as the anchor. Regression analysis was used to identify independent preoperative predictors of achieving the PASS.

Results: The PASS was defined as OKS ≥31 (area under the curve [AUC] 0.865, 95% CI 0.850-0.881) with 2333 (70.6%) patients achieving this. Patients not achieving a PASS were younger, had a higher BMI, and worse baseline PROMs (all p < 0.001). Higher preoperative OKS (odds ratio [OR] 1.09 per point) and EQ-VAS (OR 1.01 per point) were independently associated with achieving a PASS (both p < 0.001). A preoperative OKS ≤19 was associated with achieving a PASS (AUC 0.707). PASS achievers were more likely to be satisfied (OR 15.3, p < 0.001), though 54.4% of non-achievers were also satisfied.

Conclusion: The PASS was defined as ≥31 points in the OKS at 6 months following TKA. Lower preoperative OKS and EQ-VAS scores were associated with failure to achieve this threshold. While PASS attainment was associated with patient satisfaction, 54% of those not achieving a PASS were still satisfied, highlighting a limitation of this PROM threshold in isolation.

Level of evidence: Retrospective study, Level III.

Introduction: Knee arthroplasty is an effective treatment option for managing advanced osteoarthritis and rheumatoid arthritis, even in elderly patients. However, super-elderly patients face increased risks of postoperative complications such as in-hospital mortality, deep vein thrombosis, pneumonia, cerebrovascular events, and cognitive dysfunction. This study aims to analyze postoperative complications in super-elderly patients (aged 85 years and older) and elderly patients (aged 70-84 years) who underwent total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) using Japan's nationwide DPC database. The analysis was conducted after adjusting for confounding factors through propensity score matching.

Methods: We conducted a retrospective study of 200,925 patients who underwent TKA or UKA between 2016 and 2023. After propensity score matching (1:1) based on age, sex, body mass index, surgical method, and comorbidities, 21,117 patients were included in each group. Postoperative complications, including in-hospital mortality, deep vein thrombosis, pneumonia, cerebrovascular events, and cognitive dysfunction, were analyzed. Multivariate logistic regression identified independent risk factors for postoperative complications.

Results: The super-elderly group exhibited higher odds ratios for pneumonia (2.227, 95% CI: 1.494-3.319), cerebrovascular events (1.720, 95% CI: 1.305-2.266), and cognitive dysfunction (1.767, 95% CI: 1.485-2.103). They also had more extended hospital stays and higher blood transfusion requirements. However, no significant differences were observed for deep vein thrombosis, pulmonary embolism, or in-hospital mortality.

Conclusion: Super-elderly patients exhibit increased risks for certain complications, though not for mortality. When clinically appropriate, performing knee arthroplasty before the age of 85 may help reduce these risks.

Background: Total knee arthroplasty (TKA) and distal femoral replacement (DFR) can be used in limb-salvage after resection of bony tumors, but few reports have examined patient-reported outcome measurements (PROMs) with survival data in young patients. This study analyzed individuals who underwent TKA/DFR for neoplasm at a young (≤40) age, to report outcomes and survival experience.

Methods: A retrospective study on 12 TKAs/23 DFRs was conducted between January 1990-2020 in 35 patients ≤40 years old. Electronic medical records were reviewed to identify patients with neoplasm, and collect data. Patients were contacted to obtain PROMs.

Results: The median age (interquartile range) at surgery for TKAs and DFRs was 26.7 (22.7-34.0) and 24.6 years (20.9-28.4), respectively. Median follow-up was 3.95 (0.33-8.14) and 3.01 years (1.72-6.07). TKAs were more commonly due to complications after allograft reconstruction (75.0% vs. 0.00%, p < 0.0001), had lower blood loss (250 vs. 800 ml, p = 0.01) and a higher rate of tourniquet use (75.0% vs. 34.8%, p = 0.04). Revision-free survival (8-year) was 54.7% (95% confidence interval (CI): 13.7%-83.3%) for TKAs and 37.9% (95% CI: 10.4%-66.0%, p = 0.12) for DFRs. For TKAs, median KOOS Jr. was 76.3 (76.3-79.9), VR-12-Physical was 50.0 (40.5-51.7), VR-12-Mental was 40.8 (32.6-45.8), LEAS was 12.0 (12.0-13.0), and FJS was 23.0 (19.0-25.0), without statistical difference from the DFR group.

Conclusion: Patients ≤40 years old who underwent TKAs/DFRs for neoplastic disease demonstrated a similarly high postoperative complication rate and poor long-term survival. Almost all PROMs were favorable, reflecting a more promising postoperative experience than survival curves might demonstrate.