Radiographic Knee Research Articles

Cut-off value for the posterior tibial slope indicating the risk for retear of the anterior cruciate ligament.

The significance of the posterior tibial slope (PTS) has increasingly come into focus in anterior cruciate ligament (ACL) reconstruction being a risk factor for ACL graft failure. Nevertheless, inconsistent data on the critical value of the PTS exist. The purpose of this study was to define a cut-off value for the PTS in ACL surgery. In a retrospective cohort study, 350 revision ACL reconstructions (ACL-RR) with a failed ACL hamstring graft and 350 primary ACL reconstructions (ACL-R) were matched according to age, gender, concomitant injuries and graft characteristics and compared to a healthy control group. Using the proximal anatomic axis, lateral knee radiographs were evaluated for the PTS, interrater reliability was defined, ROC curves, Fischer's exact test and Baptista-Pike method were applied to define specificity and the odds ratio for a critical PTS value. Radiographic evaluation proved excellent interrater reliability (intraclass correlation coefficient 0.969). Evaluation of the PTS revealed 10.0 ± 2.2 (5-15) degrees in the ACL-RR group, 7.8 ± 1.8 (4.2-13) degrees in the ACL-R group and 6.6 ± 1.9 (3.6-12) degrees in the control group with significant differences between the groups (p < 0.001). A PTS value of 10.1 degrees proved a specificity of 98% for the prediction of an ACL graft failure and indicated an 11-fold risk for a retear of the ACL. A PTS exceeding 10.1 degrees carries an 11-fold risk for ACL graft failure and, therefore, should be considered in ACL reconstruction. These findings might serve as a cut-off value for the indication of a slope-reducing high tibial osteotomy in ACL surgery. Level III.

Diagnostic performance of ChatGPT in tibial plateau fracture in knee X-ray.

Tibial plateau fractures are relatively common and require accurate diagnosis. Chat Generative Pre-Trained Transformer (ChatGPT) has emerged as a tool to improve medical diagnosis. This study aims to investigate the accuracy of this tool in diagnosing tibial plateau fractures. A secondary analysis was performed on 111 knee radiographs from emergency department patients, with 29 confirmed fractures by computed tomography (CT) imaging. The X-rays were reviewed by a board-certified emergency physician (EP) and radiologist and then analyzed by ChatGPT-4 and ChatGPT-4o. The diagnostic performances were compared using the area under the receiver operating characteristic curve (AUC). Sensitivity, specificity, and likelihood ratios were also calculated. The results indicated a sensitivity and negative likelihood ratio of 58.6% (95% CI: 38.9 - 76.4%) and 0.4 (95% CI: 0.3-0.7) for the EP, 72.4% (95% CI: 52.7 - 87.2%) and 0.3 (95% CI: 0.2-0.6) for the radiologist, 27.5% (95% CI: 12.7 - 47.2%) and 0.7 (95% CI: 0.6-0.9) for ChatGPT-4, and 55.1% (95% CI: 35.6 - 73.5%) and 0.4 (95% CI: 0.3-0.7) for ChatGPT4o. The specificity and positive likelihood ratio were 85.3% (95% CI: 75.8 - 92.2%) and 4.0 (95% CI: 2.1-7.3) for the EP, 76.8% (95% CI: 66.2 - 85.4%) and 3.1 (95% CI: 1.9-4.9) for the radiologist, 95.1% (95% CI: 87.9 - 98.6%) and 5.6 (95% CI: 1.8-17.3) for ChatGPT-4, and 93.9% (95% CI: 86.3 - 97.9%) and 9.0 (95% CI: 3.6-22.4) for ChatGPT4o. The area under the receiver operating characteristic curve (AUC) was 0.72 (95% CI: 0.6-0.8) for the EP, 0.75 (95% CI: 0.6-0.8) for the radiologist, 0.61 (95% CI: 0.4-0.7) for ChatGPT-4, and 0.74 (95% CI: 0.6-0.8) for ChatGPT4-o. The EP and radiologist significantly outperformed ChatGPT-4 (P value = 0.02 and 0.01, respectively), whereas there was no significant difference between the EP, ChatGPT-4o, and radiologist. ChatGPT-4o matched the physicians' performance and also had the highest specificity. Similar to the physicians, ChatGPT chatbots were not suitable for ruling out the fracture.

A deep learning based automatic two-dimensional digital templating model for total knee arthroplasty

BackgroundPreoperative templating is an important step for total knee arthroplasty (TKA), facilitating hospital personnel in the anticipation and preparation of necessary surgical resources. Despite its importance, this process currently lacks automation. This study aimed to develop an artificial intelligence (AI) model to automate implant size prediction.MethodsA total of 13,281 (2938 anteroposterior, 10,343 lateral) knee radiographs obtained from the authors’ institute were utilized for model training, with 2302 (1034 anteroposterior, 1268 lateral) images set apart for validation and testing. The templating AI model integrates a pipeline composed of multiple steps for automated implant size estimation. To predict implant size, anterioposterior (AP) and lateral radiograph predictions were merged, selecting the smaller of the predicted sizes to prevent implant overhang. The model’s size predictions were validated with 81 real TKA data set apart from the training data, and its accuracy was compared to that of manual templating by an orthopedic specialist. Predictions matching the actual implanted sizes were labeled “exact” and those within one size, “accurate.” The influence of patient characteristics on the model’s prediction accuracy was also analyzed. The measurement time elapsed for implant sizing was recorded for both the AI model and the orthopedic specialist. Implant position predicted by the model was validated by comparing insert locations with postoperative images.ResultsCompared with data from 81 actual TKA procedures, the model provided exact predictions for 39.5% of femoral and 43.2% of tibial components. Allowing a one-size margin of error, 88.9% of predictions were deemed “accurate” for both components. Interobserver reliability (Cohen’s kappa) were 0.60 and 0.70 for femoral and tibial implants, respectively, both classified as “substantial.” The orthopedic specialist produced results accurate within one-size margin of error in 95.1% and 100% of cases for femoral and tibial components, respectively. Interobserver reliability between the orthopedic specialist and ground truth was 0.76 and 0.8 for femoral and tibial components, respectively. The measurement time per case was 48.7 s for the AI model, compared with 97.5 s for the orthopedic specialist. Compared with postoperative radiographs, predicted implant position had an error of less than 4 mm on average.ConclusionsAn AI-based templating tool for TKA was successfully developed, demonstrating satisfactory accuracy and efficiency. Its application could significantly reduce the clinical workload in TKA preparation.

High Variability of Lateral Extra-articular Tenodesis Femoral Tunnel Position With Landmark-Based Techniques

Background: The utilization of lateral extra-articular tenodesis (LET) augmentation for anterior cruciate ligament reconstruction has increased. Various fixation points have been recommended based on tactile and anatomic landmarks; however, there is limited reporting of the accuracy or precision of these techniques in clinical practice. Purpose/Hypothesis: The purpose of this study was to evaluate whether LET fixation points identified using anatomic landmarks and tactile techniques would fall within a predefined radiographic zone. It was hypothesized that the majority of LET fixation points would be inside the radiographic zone. Study Design: Cross-sectional study; Level of evidence, 4. Methods: Postoperative lateral knee radiographs of patients who underwent anterior cruciate ligament reconstruction with LET using a landmark-based technique without fluoroscopy between January 2018 and September 2023 were reviewed. Fixation points were measured by 2 raters based on their distance from an extension of the posterior femoral cortex line (PFCL) distally and a line perpendicular to the PFCL at the posterior condylar flare (PCF). Patients were excluded if the tunnel position could not be identified or if postoperative radiographs were malrotated. The mean LET position and percentage of points within the radiographic isometric zone, defined as 4 ± 4 mm posterior and 4 ± 3 mm anterior to the PFCL and 6 ± 4 mm distal and 20 ± 5 mm proximal to the PCF were calculated. Results: Complete data sets were obtained for 47 cases. The mean LET position was 6.4 ± 7.1 mm (range, –9 to 27.3 mm) anterior to the PFCL and 1.8 ± 7.6 mm (range, –16.7 to 12.6 mm) proximal to the PCF. Overall, 53% of LET fixation points were within the predefined radiographic zone. Of the malpositioned tunnels (n = 22), their locations relative to the radiographic zone were anterior (n = 18), posterior (n = 2), proximal (n = 1), and anterior and distal (n = 1). Conclusion: This study found large variation in the location of LET fixation points, and almost half of fixation points were outside the predefined radiographic zone. Accurate and precise tunnel placement is one of multiple factors that may be important to minimize the risk of lateral compartment overconstraint, anterior cruciate ligament graft failure, and anisometry leading to LET graft loosening.

Modeling of Healing of Intra-Articular Fractures of Long Tubular Bones in Rats

Background: We present a new original method of modeling an intra-articular fracture of the long tubular bone in laboratory animals.Objective: To create a new experimental model of an intra-articular fracture of the long tubular bone and to approve it for comprehensive evaluation of morphofunctional parameters of cartilage and bone healing.Materials and methods: The experiment was performed on 30 white sexually mature Wistar rats. Modeling involved layer-by-layer dissection of tissues along the anteromedial surface and formation of an incomplete fracture of the femoral medial condyle using a sharp L-shaped working end of an 0.2 × 0.2 сm instrument perpendicular to the medial condyle with a slight single muscle force. The rats were euthanized in groups of 10 animals on days 7, 14, and 30. We performed knee radiography and determined blood osteocalcin and BMP-7 levels. The Mankin score was used in the histological evaluation of the articular cartilage changes. The groups were compared using the Kruskal-Wallis test. P &lt; .05 was considered statistically significant.Results: We noted statistically significant differences (P &lt; .0001) when comparing the groups using the Mankin score. The post hoc test revealed statistically significant differences in the Mankin scores between days 7 and 14 (P = .014) and between days 7 and 30 (P &lt; .0001). Group comparisons showed no statistically significant differences in blood osteocalcin levels (P = .518). However, there were statistically significant differences (P = .0028) between the groups in blood BMP-7 levels. The post hoc test revealed statistically significant differences in blood BMP-7 levels between days 7 and 14 (P = .048) and between days 14 and 30 (P = .0195).Conclusions: The developed experimental model of intra-articular fractures of long tubular bones allows for a comprehensive assessment of reparative processes of cartilage and bone tissue. The model is close to the real mechanism of pathology development.

AI-BASED AUTOMATED VARUS/VALGUS ALIGNMENT MEASUREMENT IN STANDARD KNEE RADIOGRAPHS

IntroductionAccurate assessment of alignment in pre-operative and post-operative knee radiographs is important for planning and evaluating knee replacement surgery. Existing methods predominantly rely on manual measurements using long-leg radiographs, which are time-consuming to perform and are prone to reliability errors. In this study, we propose a machine-learning-based approach to automatically measure anatomical varus/valgus alignment in pre-operative and post-operative standard AP knee radiographs.MethodWe collected a training dataset of 816 pre-operative and 457 one-year post-operative AP knee radiographs of patients who underwent knee replacement surgery. Further, we have collected a separate distinct test dataset with both pre-operative and one-year post-operative radiographs for 376 patients. We manually outlined the distal femur and the proximal tibia/fibula with points to capture the knee joint (including implants in the post-operative images). This included point positions used to permit calculation of the anatomical tibiofemoral angle. We defined varus/valgus as negative/positive deviations from zero. Ground truth measurements were obtained from the manually placed points. We used the training dataset to develop a machine-learning-based automatic system to locate the point positions and derive the automatic measurements. Agreement between the automatic and manual measurements for the test dataset was assessed by intra-class correlation coefficient (ICC), mean absolute difference (MAD) and Bland-Altman analysis.ResultAnalysing the agreement between the manual and automated measurements, ICC values were excellent pre-/post-operatively (0.96, CI: 0.94-0.96) / (0.95, CI: 0.95-0.96). Pre-/post-operative MAD values were 1.3°±1.4°SD / 0.7°±0.6°SD. The Bland-Altman analysis showed a pre-/post-operative mean difference (bias) of 0.3°±1.9°SD/-0.02°±0.9°SD, with pre-/post-operative 95% limits of agreement of ±3.7°/±1.8°, respectively.ConclusionThe developed machine-learning-based system demonstrates high accuracy and reliability in automatically measuring anatomical varus/valgus alignment in pre-operative and post-operative knee radiographs. It provides a promising approach for automating the measurement of anatomical alignment without the need for long-leg radiographs.AcknowledgementsThis research was funded by the Wellcome Trust [223267/Z/21/Z].

Arthroscopic Partial Meniscectomy in Adult Patient with Symptomatic Discoid Lateral Meniscus: A Case Report

Introduction: For many years, the discoid meniscus was synonymous with snapping knee syndrome. incidence of discoid lateral meniscus is estimated to be 0.4% to 17%, whereas the discoid medial meniscus is extremely rare (0.1% to 0.3%). It has been reported that about 20% of cases are bilateral. Patients with discoid lateral meniscus (DLM) often show normal plain radiography findings but may also show subtle indirect signs. Case Presentation: Female, 59 years old, complained of pain on her left knee after walking and climbing stairs for the last two months. On examination, the range of motion of knee joint was limited due to the pain for flexion more than 90°. Patient had medial joint line tenderness, and a McMurray test elicited pain on the lateral joint line. Radiographs of the left knee showed lateral joint space widening and high fibular head. Arthroscopic examination of the left knee confirmed the presence of discoid lateral menisci (DLM). Discussion: Discoid lateral meniscus (DLM), often referred to as "popping knee syndrome," is an abnormal variation of the meniscus, primarily affecting the lateral side and more common in young individuals. This condition increases the risk of knee injury, especially if the ligament attachment to the tibia is absent. In our case, radiographic findings and a positive McMurray test led to the diagnosis, confirmed by arthroscopy showing a complete DLM. While some recommend for total meniscectomy, studies suggest that partial meniscectomy can offer good initial results, though long-term outcomes may vary. Conclusion: In symptomatic DLM, surgical treatment is necessary to treat the patient. Arthroscopic partial meniscectomy is the preferred surgical procedure to treat symptomatic DLM. Keywords: Discoid lateral meniscus, arthroscopic menisectomy, WOMAC score

An MRI-Based Method for the Morphologic Assessment of the Anterior Tibial Tuberosity.

Background: A prominent anterior tibial tuberosity (or tibial tubercle) can be seen in ongoing Osgood-Schlatter disease (OSD) in teenagers or as a sequela of OSD in adults. Current radiological methods do not provide a true anatomical assessment of the tibial tuberosity; therefore, we proposed and developed a Magnetic Resonance Imaging (MRI)-based method for measuring the anterior tibial tuberosity index, aiming to deal with the current lack of effective techniques for accurately assessing these particular morphologic features. Methods: A retrospective study included 47 knees with tibial tuberosity measurements on both true sagittal MPR images of 3D proton density (PD)-weighted MRI sequences and lateral knee radiographs. The same landmarks were followed and the anterior tibial tuberosity index (ATTI) was measured. Results: The comparison of the results obtained by the two methods demonstrates that our method is reliable and reproducible with substantial inter- and intra-observer agreement. The intraclass correlation coefficient was 0.9250 (95% CI: 0.8654 to 0.9582), indicating excellent reliability between the two methods. A strong positive correlation was also identified, with a correlation coefficient of r = 0.8746 (95% CI: 0.7845 to 0.9286, p < 0.0001) between the two methods. No significant deviation from linearity was observed by analyzing the linear model validity using the cusum test (p = 0.62). Conclusions: Based on these results, we encourage the use of 3D PD-weighted MRI sequences for the measurement of the anterior tibial tuberosity on MRI in order to avoid unnecessary exposure to ionizing radiation and potentially obtain a more accurate measurement. Future larger studies should also explore the benefit of utilizing 3D sequences over 2D lateral projections to minimize measuring bias.

Adductor tubercle appears more posterior on radiographs of knees with trochlear dysplasia

PurposeThe purpose of this study was to compare the radiographic positions of commonly utilized landmarks between symptomatic and normal knees and to assess the influence of morphologic risk factors. Methods3D models were created from knees of patients with patellar instability and compared to control knees. On the 3D models, the adductor tubercle, medial epicondyle and gastrocnemius tubercle were marked. A 2D view was created from these models to simulate radiographs, and the radiographic location of each landmark was described with respect to the anteroposterior relation to the posterior cortical line, and proximal-distal relationship to the posterior condylar line. The position of each landmark was compared between symptomatic and control groups and assessed for variations in position with severity of anatomic risk factors. Results40 patients were included in this study. On the 2D views, the medial epicondyle was found to be more posterior and more distal than in the control group. Association between severity of trochlear dysplasia and posterior position of the adductor tubercle trended toward significance (R=0.43, R2=0.18, p=0.058). In symptomatic knees with trochlear dysplasia, the radiographic landmark for the medial epicondyle was posterior by 3.3mm (p=0.052), adductor tubercle by 2.7mm (p=0.009), and gastrocnemius tubercle by 3.9mm (p=0.010) when compared to symptomatic knees without dysplasia. ConclusionThis study demonstrates that commonly utilized anatomic landmarks are more posterior and distal on radiographs in knees with patellar instability when compared to normal knees. Trochlear dysplasia is associated with the radiographic landmarks of the adductor and gastrocnemius tubercles appearing 3mm posterior to those without dysplasia, and its severity is associated with posterior radiographic appearance of the adductor tubercle. Level of EvidenceIII, Retrospective Case Control

Frontal plane mechanical leg alignment estimation from knee x-rays using deep learning

ObjectiveLower limb malalignment can complicate symptoms and accelerate knee osteoarthritis (OA), necessitating consideration in study population selection. In this study, we develop and validate a deep learning model that classifies leg alignment as “normal” or “malaligned” from knee antero-posterior (AP)/postero-anterior (PA) radiographs alone, using an adjustable hip-knee-ankle (HKA) angle threshold. Material and MethodsWe utilized 8,878 digital radiographs, including 6,181 AP/PA full-leg x-rays (LLRs) and 2,697 AP/PA knee x-rays (2,292 with positioning frame, 405 without). The model’s evaluation involved two steps: In step 1, the model’s predictions on knee images cropped from LLRs were compared against the ground truth from the original LLRs. In step 2, the model was tested on knee AP radiographs, using corresponding same-day LLRs as a proxy for ground truth. ResultsThe model effectively classified alignment, with step one achieving sensitivity and specificity of 0.92 for a threshold of 7.5°, and 0.90 and 0.85 for 5°. For positioning frame images, step two showed a sensitivity of 0.85 and specificity of 0.81 for 7.5°, and 0.79 and 0.74 for 5°. For non-positioning frame images, sensitivity and specificity were 0.91 and 0.83 for 7.5°, and 0.9 and 0.86 for 5°. ConclusionThe model developed in this study accurately classifies lower limb malalignment from AP/PA knee radiographs using adjustable thresholds, offering a practical alternative to LLRs. This can enhance the precision of study population selection and patient management.

Comparison of Imaging Characteristics in Pediatric Patients With Trochlear Versus Medial Femoral Condyle Osteochondritis Dissecans.

Although osteochondritis dissecans (OCD) lesions are well-described in the femoral condyles and have been associated with varus limb alignment, there is limited data on OCD lesions in the trochlea. To compare the baseline imaging characteristics in pediatric patients with trochlear OCD with those with medial femoral condyle (MFC) OCD to understand whether measures of coronal plane alignment predispose to OCD development by anatomic location. Cross-sectional study; Level of evidence, 3. This study retrospectively reviewed all pediatric patients (age ≤18 years) diagnosed with isolated trochlear OCD at a tertiary-care medical center from January 2016 to May 2023; all included patients had weight-bearing hip-to-ankle alignment radiographs. Hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), mechanical axis deviation (MAD), Caton-Deschamps Index (CDI), patellar tilt, and sulcus angle were measured on initial/preoperative anteroposterior and lateral knee radiographs. Tibial tubercle-trochlear groove (TT-TG) distance and OCD lesion size were measured on initial/preoperative magnetic resonance imaging sequences. Patients were 1 to 2 matched based on age (±2 years) and sex to a cohort with isolated MFC OCD. A total of 18 extremities in 16 patients were included in the trochlear OCD cohort and matched to 36 extremities in the MFC OCD cohort. The mean age at the first clinical visit for all patients was 14.8 ± 1.5 years and did not differ significantly between the two groups (P = .40). The extremities with trochlear OCD had significantly less varus HKA (1°± 2° vs -1°± 2°; P = .004) and MAD (4 ± 8 vs -3 ± 8 mm; P = .004) compared with the MFC cohort as well as lower mLDFA (86°± 2° vs 88°± 2°; P = .004). There were no differences in MPTA, CDI, patellar tilt, sulcus angle, TT-TG distance, or OCD lesion size between groups. Pediatric patients with trochlear OCD had statistically less varus coronal plane alignment compared with age- and sex-matched patients with MFC OCD, with the latter exhibiting more significant varus based on the HKA and MAD.

Comparison of Different Techniques for Measuring Posterior Tibial Slope

Objectives: The posterior tibial slope assessment is crucial in preoperative planning for various surgeries. Different measurement methods exist, but no study has compared them. This study aims to verify the equivalence of four techniques for measuring the posterior tibial slope in lateral knee radiographs and assess inter-observer reliability among evaluators with different academic training levels. Methods: Forty-three lateral knee radiographs from patients with osteoarthritis and ligament injuries who had indications for tibial osteotomy were evaluated. Three evaluators with varying levels of academic training performed measurements using four parameters: anterior cortex, posterior cortex, anatomical axis of the proximal tibia, and anatomical axis of the proximal fibula. Results were expressed as mean values ± standard deviation, and a p-value &lt; 0.05 was considered statistically significant. Results: The average degree values were 12.6±4.4 for the anterior cortex, 10.1±3.8 for the tibial axis, 7.8±4.1 for the posterior cortex, and 11.6±4.6 for the fibular axis. There was a significant difference between all these measurements, except for the comparison between the anterior cortex and the fibular axis. In terms of the tibial axis, the evaluator with the lowest level of training showed significant variation compared to the other two evaluators. Conclusion: The four methods for measuring the posterior tibial slope are not equivalent, except for the anterior cortex and fibular axis measurements. Lower-level trained professionals had difficulty performing tibial axis measurements. Further studies are needed to determine the most accurate technique for assessing posterior tibial slope angulation

Evaluation of the Effect of Menisci on Tibial Slope and the Correlation With Body Mass Index.

Background One of the important factors affecting the biomechanics of the knee joint is the posterior tibial slope which is the tibial plateau's anatomical inclination toward the posterior of the sagittal plane. This inclination, which affects anterior-posterior stability, is important for the kinematics of the knee joint. Changes in the tibial slope may cause a deficit in the stability and function of the knee joint. We aimed to examine the inclination of the posterior horn of the meniscus and posterior tibial slope in healthy individuals and investigate the effect of body mass index on these measurements. Methodology A total of 34 magnetic resonance images and lateral knee radiographs were evaluated in this study. The study included individuals aged 15 to 78 without a history of previous injury or surgery of their knee. Results In the measurements made on magnetic resonance images, a statistically significant difference was found between 25% lateral meniscus slope (mean ± SD = 28.08 ± 1.88) and 25% medial meniscus slope (mean ± SD = 27.31 ± 1.41) (p = 0.05). At the same time, a statistically significant difference (p = 0.011) was found between 25% medial combined slope (mean ± SD = 29.05 ± 3.80) and 25% lateral combined slope (mean ± SD = 30.62 ± 2.99). There was no statistically significant difference between tibial and meniscus slopes, body mass index, gender, and age. Conclusions Our study results have shown that the 25% lateral meniscus and combined slopes are greater than the 25% medial meniscus slope.

Assessment of validity, reliability, and feasibility of OMERACT ultrasound knee osteoarthritis scores in Egyptian patients with primary knee osteoarthritis

BackgroundUltrasound (US) can evaluate all joint components affected by knee osteoarthritis (KOA); however, standardized scoring of US-detected pathology is needed to improve its diagnostic and monitoring capabilities.ObjectivesTo examine the validity, reliability, and feasibility of the Outcome Measures in Rheumatology (OMERACT) ultrasound scoring for KOA, comparing with clinical and radiography measures, using predefined cutoff values.MethodsThis cross-sectional study included 75 Egyptian patients with primary KOA. All patients had Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, bilateral knee radiography, and ultrasonography. Inter-observer reliability of ultrasound was evaluated in 30 knees by another newly trained operator.ResultsMost of the OMERACT-US KOA scores showed significant associations with WOMAC clinical scores, except for femoral cartilage damage and effusion. The synovitis score was significantly associated with WOMAC–pain score (p-value 0.046), while medial meniscus extrusion (MME) and medial osteophytes were significantly associated with WOMAC–stiffness score (p-value 0.009 and 0.023, respectively). MME and synovitis were significantly associated with WOMAC–physical score (p-value 0.035 and 0.020, respectively). The ultrasound scores also showed a strong correlation with radiographic scoring. Inter-observer reliability ranged from moderate to excellent agreement (k = 0.58 to k = 0.83); it was highest for lateral osteophytes (k = 0.83), good agreement for synovitis (k = 0.72), any osteophytes (k = 0.71), damage of femoral cartilage (k = 0.70), and moderate agreement for medial osteophytes (k = 0.58) and MME (k = 0.59).ConclusionOMERACT-US scoring system for KOA demonstrated validity, reliability, and feasibility for evaluating both structural and inflammatory components. Using cutoff values improved the scoring reliability for osteophytes and MME.Key Points• OMERACT-US scores provide a valid assessment of inflammatory and structural components of knee osteoarthritis.• The following changes may improve the performance of the OMERACT-US scores.a. The binary score for effusion and synovial hypertrophy can be omitted, as they have no added value.b. A semi-quantitative grading for effusion may capture the impact of effusion on clinical outcomes.c. Added cutoff values to score medial meniscal extrusion, osteophytes, and pathological effusion improved the respective scores’ reliability.d. Applying the updated OMERACT definition of synovitis.• OMERACT-US scores are reliable to be used with a newly trained operator, particularly when cutoff values are included, and proper training time is provided.• The OMERACT-US score is feasible to be used in clinical practice, as the time taken to perform was short, even for a newly trained operator.

Comparison Between Ultrasonography and Radiography in the Detection of Epiphyseal Ossification Centers of the Knee in Infants With Permanent Congenital Hypothyroidism.

To demonstrate the usefulness of ultrasonography in detecting knee ossification centers in infants with permanent congenital hypothyroidism (PCH). From 2011 to 2021, all infants with PCH referred for thyroid ultrasound also underwent left knee ultrasound and radiography on the same day. Knee radiographs were compared with knee sonograms. Two pediatric radiologists reviewed the consensus knee radiographs and sonograms to identify femoral and tibial epiphyseal ossification centers (presence/absence). The concordance between ultrasonography and radiography was assessed. Another radiologist conducted a second late review to evaluate interobserver agreement. We identified 125 patients (65 girls, 60 boys) with a mean age of 24 days (5 days-5 months). On scintigraphy, the thyroid was in place in 66.4%, ectopic in 24%, and absent in 9.6% of patients. The femoral center was observed in 108 patients (86.4%) via sonography and 106 patients (84.8%) via radiography. The tibial center was observed in 84 patients (67.2%) via sonography and radiography. Both femoral and tibial centers were present on sonography and radiography in 84 patients (67.2%). A single nucleus was present in 24 patients (19.2%) on sonography and 22 patients (17.6%) on radiography; it corresponded to the femoral center in all patients. The concordance between ultrasonography and radiography was 99% and 100%, respectively, for the detection of the femoral and tibial centers. Interobserver agreement was substantial to almost perfect for both ultrasonography and radiography. Ultrasonography is as effective as radiography in detecting knee ossification centers in PCH. It can be performed at the same time as thyroid examination, in place of radiography.

Quantitative analysis of effectiveness and associated factors of exercise on symptoms in osteoarthritis: a pharmacodynamic model-based meta-analysis

ObjectiveThis study aims to evaluate the time point and magnitude of peak effectiveness of exercise and the effects of various exercise modalities for osteoarthritis (OA) symptoms and to identify factors...

A radiographic artificial intelligence tool to identify candidates suitable for partial knee arthroplasty

IntroductionKnee osteoarthritis is a prevalent condition frequently necessitating knee replacement surgery, with demand projected to rise substantially. Partial knee arthroplasty (PKA) offers advantages over total knee arthroplasty (TKA), yet its utilisation remains low despite guidance recommending consideration alongside TKA in shared decision making. Radiographic decision aids exist but are underutilised due to clinician time constraints.Materials and methodsThis research develops a novel radiographic artificial intelligence (AI) tool using a dataset of knee radiographs and a panel of expert orthopaedic surgeons’ assessments. Six AI models were trained to identify PKA candidacy.Results1241 labelled four-view radiograph series were included. Models achieved statistically significant accuracies above random assignment, with EfficientNet-ES demonstrating the highest performance (AUC 95%, F1 score 83% and accuracy 80%).ConclusionsThe AI decision tool shows promise in identifying PKA candidates, potentially addressing underutilisation of this procedure. Its integration into clinical practice could enhance shared decision making and improve patient outcomes. Further validation and implementation studies are warranted to assess real-world utility and impact.

Uncertainty-Aware Deep Learning Characterization of Knee Radiographs for Large-Scale Registry Creation

BackgroundWe present an automated image ingestion pipeline for a knee radiography registry, integrating a multilabel image-semantic classifier with conformal prediction-based uncertainty quantification and an object detection model for knee hardware. MethodsAnnotators retrospectively classified 26,000 knee images detailing presence, laterality, prostheses, and radiographic views. They further annotated surgical construct locations in 11,841 knee radiographs. An uncertainty-aware multilabel EfficientNet-based classifier was trained to identify the knee laterality, implants, and radiographic view. A classifier trained with embeddings from the EfficientNet model detected out-of-domain images. An object detection model was trained to identify 20 different knee implants. Model performance was assessed against a held-out internal and an external dataset using per-class F1 score, accuracy, sensitivity, and specificity. Conformal prediction was evaluated with marginal coverage and efficiency. ResultsClassification Model with Conformal Prediction: F1 scores for each label output > 0.98. Coverage of each label output was > 0.99 and the average efficiency was 0.97. Domain Detection Model:The F1 score was 0.99, with precision and recall for knee radiographs of 0.99. Object Detection Model:Mean average precision across all classes was 0.945 and ranged from 0.695 to 1.000. Average precision and recall across all classes were 0.950 and 0.886. ConclusionsWe present a multilabel classifier with domain detection and an object detection model to characterize knee radiographs. Conformal prediction enhances transparency in cases when the model is uncertain.

No clinically relevant relationship between different quantitative measurement methods of the lateral femoral condyle morphology on lateral radiographs in anterior cruciate ligament-injured patients.

To clarify whether different methods of quantifying lateral femoral condyle (LFC) bone morphology as risk factors for anterior cruciate ligament (ACL) injury on lateral radiographs should be considered as individual risk factors and to assess inter- and intraobserver reliability. We retrospectively reviewed 487 patients undergoing primary ACL reconstruction at our institution. Routine lateral radiographs of the injured knees were utilized to measure the following parameters: LFC ratio (LFCR), height of LFC to anteroposterior diameter ratio (HAPR), femur tibia size ratio (FTSR), tibia to posterior femoral condyle ratio (TPFCR) and Porto ratios (XY/AB; B/AB; B/XY). Malrotated radiographs were excluded. Pearson's correlation coefficients were used to identify relationships. Intraclass correlation coefficients were calculated for inter- and intraobserver reliability for two raters. Fifty-eight patients were included. Means and standard deviations for LFCR were 63.7% ± 2.8%, HAPR 0.35 ± 0.02, FTSR 1.23 ± 0.07, TPFCR 2.99 ± 0.28, XY/AB 0.41 ± 0.08, B/AB 1.20 ± 0.06 and B/XY 3.05 ± 0.58. Significant correlations were observed between FTSR and XY/AB (r = 0.425), B/AB (r = 0.582) and TPFCR (r = -0.326), between XY/AB and HAPR (r = -0.309) and B/XY (r = -0.933) and between TPFCR and B/AB (r = 0.302). Intraobserver agreement was excellent for LFCR, HAPR, FTSR, TPFCR and B/AB and good for XY/AB and B/XY. Interobserver agreement varied from poor for XY/AB and B/XY, good for HAPR, B/AB, FTSR and TPFCR to excellent for LFCR. Different methods of quantifying LFC bone morphology should be considered as individual risk factors, characterized by good to excellent intraobserver reliability, but highly variable interobserver reliability. Level III.

Radiographic Tibial Tunnel Assessment After Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts and Biocomposite Screws: A Prospective Study With 10-Year Follow-up.

Biocomposite screws reportedly provide equivalent graft fixation in anterior cruciate ligament reconstruction (ACLR) to metallic screws while simplifying subsequent imaging and surgery. One purported complication of biocomposite screws is paradoxical tunnel widening. Previous studies on beta-tricalcium phosphate screws have only reported outcomes at short- and midterm follow-up. To radiographically assess the tibial tunnel 10 years after ACLR using hamstring tendon autografts and biocomposite interference screws in anatomic single-bundle (SB) and double-bundle (DB) methods. Case series; Level of evidence, 4. Of the 105 initially recruited patients, 61 (58%) completed all follow-up evaluations for inclusion in this long-term study. A total of 26 patients received anatomic SB ACLR and 35 patients received DB ACLR with biocomposite interference screws containing beta-tricalcium phosphate in the tibia. Weightbearing anteroposterior and lateral radiographs of the index knee were taken in the early postoperative period and at 2, 5, and 10 years postoperatively; computed tomography (CT) imaging was performed at 10-year follow-up. Subjective and objective clinical assessments were recorded preoperatively and at 10-year follow-up. The mean follow-up period was 122 months. In 76% of radiographs in the SB group, the width of the tibial tunnel had not increased at 10 years compared with the early postoperative period. The mean tibial tunnel volume on CT in the SB group was 2.04 cm3 (± 0.85 cm3). In the DB group, the posterolateral tunnel width had not increased in 69% of radiographs; the same was found in 63% of radiographs for the anteromedial tunnel at 10-year follow-up. The mean posterolateral tunnel volume on CT was 2.04 cm3 (±1.92 cm3) and the mean anteromedial tunnel volume was 1.38 cm3 (±0.54 cm3). There was no correlation between tunnel widths and KT-1000 arthrometer assessments. There was a moderate but statistically significant correlation between SB tibial tunnel volume on CT imaging and KT-1000 arthrometer anterior 134 N side-to-side difference (r = 0.45; P = .039). Most patients' tibial tunnels had not increased on 1 or both radiographic views at 10-year follow-up compared with the early postoperative period after ACLR using biocomposite interference screws, with no obvious negative effect on outcomes. However, the tunnels were still visible in most patients at 10 years on standard radiographs and CT imaging.