Abnormal Knee Research Articles

A Systematic Review on Quadriceps Angle in Relation to Knee Abnormalities.

Previous studies on the quadriceps (Q) angle and its relation to knee problems have led to conflicting conclusions. In this comprehensive review, we evaluate recent studies on the Q angle and analyze the changes in Q angles.Specifically, we investigatethe variation in Q angles when measured under the following conditions: 1) under various measurement techniques; 2) between symptomatic and non-symptomatic groups; 3) between samples of men and women; 4) unilateral versus bilateral Q angles; 5) Q angle in adolescent boys and girls. It is widely believed that Q angles are more significant in symptomatic patients than in asymptomatic individuals or that the right lower leg and left lower limb are equivalent, which is supported by little scientific data. However, research states that young adult females havehigher mean Q angles than males.

Gait strategies for individuals with knee osteoarthritis when transitioning between floor and stair walking.

Objective: Individuals with knee osteoarthritis are at higher risk for falls during transitions between floor and stair walking due to their reduced lower extremity function. However, the adjust gait characteristics of knee osteoarthritis subjects for dealing with stair transitions have not been explored. We aimed to investigate gait strategies in individuals with knee osteoarthritis compared to age-matched individuals without knee OA during the transition between walking on floor and stairs. Method: Gait of 30 individuals with knee osteoarthritis and 30 individuals without knee osteoarthritis during floor-to-stair and stair-to-floor walking transitions were accessed using a 3D motion capture system. Foot-tread clearance, and angles of lower extremity joints and trunk at Foot-tread clearance timepoint were analyzed by using biomechanical software (Visual 3D). Results: Compared with asymptomatic control group, the knee osteoarthritis group demonstrated no difference in vertical Foot-tread clearance and horizontal Foot-tread clearance during stair transitions. However, ankle dorsiflexion (p = 0.01) decreased, hip flexion (p = 0.02) and trunk lateral tilt (p = 0.02) increased in knee osteoarthritis group during the stair ascent transition. Moreover, trunk lateral tilt to the support side (p = 0.003) and pelvic rotation (p = 0.03) increased, while hip abduction of the swing leg (p = 0.03) decreased during the stair descent transition in individuals with knee osteoarthritis. Conclusion: Increased trunk lateral tilt and altered angle of hip may be a strategy utilized by individuals with knee OA to increase the foot clearance ability and compensate for the disease-related loss of lower extremity strength, range of motion, and balance. However, compensatory manifestations, such as the increased lateral tilt of the trunk and movement of the gravity center may enhance the risk of falls and result in more abnormal knee joint loading.

Qualitative and Quantitative Evaluation of Morpho-Metabolic Changes in Bone Cartilage Complex of Knee Joint in Osteoarthritis Using Simultaneous 18F-NaF PET/MRI-A Pilot Study.

Background Articular cartilage (AC) loss and deterioration, as well as bone remodeling, are all symptoms of osteoarthritis (OA). As a result, an ideal imaging technique for researching OA is required, which must be sensitive to both soft tissue and bone health. Objective The aim of this study was to assess the potential of simultaneous 18F sodium fluoride (18F-NaF) positron emission tomography/magnetic resonance imaging (PET/MRI) to identify as well as classify osseous metabolic abnormalities in knee OA and to see if degenerative changes in the cartilage and bone on MRI might be correlated with subchondral 18F-NaF uptake on PET. Methods Sixteen (32 knees) volunteers with no past history of knee injury, with or without pain, were enrolled for the research from January to July 2021. The images of both knees were taken utilizing an molecular magnetic resonance (mMR) body matrix coil on a simultaneous PET/MRI biograph mMR. The acquisition was conducted after 45 minutes of intravenous infusion of 18F-NaF 185-370 MBq (5-10 mCi) over one PET bed for 40 minutes, while MRI sequences were performed simultaneously. Results All pathologies showed significantly higher maximum standardized uptake value (SUV max ) than the background. Thirty-four subchondral magic spots were identified on 18F-NaF PET without any structural alteration on MRI. Bone marrow lesions (BMLs) and osteophytes with higher MRI osteoarthritis knee score (MOAKS) score showed higher 18F-NaF uptake (grade1˂grade2˂grade3). BMLs had corresponding AC degeneration. There was discordance between grade 1 osteophytes (86.6%), sclerosis (53.7%) and grade 1 BML in cruciate ligament insertion site (91.66%); they did not have high uptake of 18F-NaF. In case of cartilage, there was significant difference between AC grades and average subchondral SUV max and T2* relaxometry (grade0˂grade1˂grade2˂grade3˂grade4). BMLs are much more metabolically active than other pathologies, while sclerosis is the least. We also found that the subchondral uptake was statistically increased in the areas of pathology: Conclusion 18F-NaF PET/MRI was able to detect knee abnormalities unseen on MRI alone and simultaneously assessed metabolic and structural markers of knee OA across multiple tissues in the joint. Thus, it is a promising tool for detection of early metabolic changes in OA.

Validation of non-radiographic APECS software in comparison with standard radiographic measurement of full-length lower limb hip-knee-ankle angle in elderly obese women

IntroductionEvidence suggests that obesity and ageing in women are linked to angular knee abnormalities. The hip-knee-ankle (HKA) angle on a full-limb radiograph is the gold standard measure of lower limb alignment. The AI Posture Evaluation and Correction System (APECS) software is a non-radiographic mobile application designed for whole-body posture assessment. Since exposure to X-ray is associated with harmful effects, there is a need to find a safe and valid alternative for measuring HKA angle. The objective of this research was to determine the validity of the non-radiographic APECS software in comparison with standard radiographic measurement of HKA angle.MethodsThe present cross-sectional diagnostic accuracy study was conducted in a tertiary care hospital of Belagavi, Karnataka, India. Overall, 45 elderly obese females aged 60–80 years with a body mass index of 25 were included. HKA angle was marked bilaterally. Full-limb radiographs were taken and angles were marked with 2.0 version software, DXM model. For the APECS software, full-limb photographs were taken with landmarks indicated with radiant markers and angles were autogenerated by the software.ResultsThe Pearson correlation coefficient between the APECS application and the gold standard (X-ray) was 0.9874 (98.74% of matching). The agreement between standard radiograph and the average of all examiners’ APECS Pro measurements (including right and left sides) equalled 94.64% (kappa = 0.8323; <i>p</i> = 0.001), which suggests very good agreement.ConclusionsThe APECS application demonstrated a high percentage of matching (98.74%) and agreement (94.64%), indicating its excellent validity in measuring HKA angle.

Clinical effect of day case arthroscopic surgery in tibial-eminence fracture in adults using button plates

BackgroundThe tibial-eminence fracture (TEF) is an anterior cruciate-ligament avulsion fracture with a low incidence. Many surgical techniques have been described, but none of them allow early functional exercise, and there are many postoperative complications.PurposesThis study aimed to evaluate the early clinical efficacy and complications of day case arthroscopic-surgery treatment of adult TEF with button plates.MethodsWe retrospectively analyzed patients with TEF treated with arthroscopic surgery. Clinical subjective evaluation included International Knee Documentation Committee (IKDC) subjective score, Lysholm Knee Score, and Visual Analog Scale (VAS) score. Knee joint scores were evaluated by Lysholm score. Clinical objective assessment included the Lachman test, anterior-drawer test (ADT), IKDC, and range of motion. We assessed patient quality of life using a life summary table. Assessment of fracture healing and internal fixation was based on lateral x-rays of the knee joint. We measured and evaluated patient satisfaction at the last follow-up in accordance with Marsh criteria.ResultsAt final follow-up (average follow-up time, 28.23 ± 3.14 months), we evaluated results from 22 patients (22 knees). Average patient age during surgery was 33.64 ± 6.96 years. Average time from injury to surgery was 6.59 ± 1.47 h. Postoperative function was better than pre-operative function in all patients. IKDC subjective score, Lysholm score, and VAS score were better at final follow-up than before surgery. Differences in Lachman test and ADT scores before and after surgery were statistically significant. According to Intra-articular button position classification, 6 patients (6 knees) showed ideal position (A), 16 patients (16 knees) showed nearly ideal position (B), and none of the patients had nonideal position (C). The fractures of 22 patients healed completely; 2 patients had a 5°–10° knee joint dysfunction, and 1 had an abnormal knee sound. According to intra-articular button position classification, the rate of ideal position was 100%. Patient satisfaction rate was 81.8%.ConclusionDay surgery using double-button plates to treat TEF could achieve anatomical reduction, power and stability, as well as good clinical efficacy.

6DOF knee kinematic alterations due to increased load levels.

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.

Force Platforms Can Accurately Predict Knee Kinetics Limb Asymmetry With Sit-to-stands During ACL Rehabilitation

Patients with ACL reconstruction presenting with lowered internal knee extensor moment during sports and mobility tasks exhibit markers of compromised articular cartilage health. Early detection and management of their knee extensor moment deficits during rehabilitation are paramount for risk reduction of future osteoarthritis. However, the technology to obtain knee moment data requires extensive training and financial resources. We seek a more affordable and less technically demanding clinical surrogate. PURPOSE: To determine if data obtained from two force platforms can accurately predict knee extensor moment asymmetry for diagnostic and training purposes early in rehabilitation. METHODS: The study is a retrospective analysis of 14 patients with unilateral ACL reconstruction who underwent motion analysis of a self-paced sit-to-stand from a 48 cm bench. All patients were engaged in rehabilitation at the time of testing. During testing, each foot was positioned on two lengthwise-aligned force platforms. Differences between limbs were tested with paired t-tests. Stepwise linear regression predicted limb symmetry in knee extensor moment with force platform variables of limb symmetry in peak aft forces (e.g. posterior), vertical forces, and differences in the fore-aft position of each leg's center of pressure. RESULTS: Patients presented with significant (p < 0.001) interlimb differences in knee extension moment (mean ± SD: involved = 0.62 ± 0.19 Nm/kg of body mass (BM); uninvolved = 1.06 ± 0.18), vertical ground reaction forces (p < 0.001, inv = 0.56 ± 0.05 BM; uninv = 0.66 ± 0.05), and aft forces (p < 0.001, inv = 0.024 ± 0.016 BM; uninv = 0.056 ± 0.021), and nearly significant for center of pressure position (p = 0.05, involved = 0.230 ± 0.04 m; uninvolved = 0.246 ± 0.026). The regression model explained a substantial portion of limb symmetry in knee extensor moment (R-squared = 0.887, p < 0.001) with all force platform variables contributing to the final model. CONCLUSIONS: The use of force platform parameters can strongly and accurately predict knee extensor moment asymmetry in patients with ACL reconstruction during rehabilitation. This prediction cluster is a promising and affordable alternative that may function as a surrogate measure of abnormal knee moment for retraining and improved clinical reasoning.

Failure of primary ACL repair with dynamic intraligamentary stabilization may result in a high risk of two-stage ACL reconstruction: a case series of ten patients

PurposeDynamic Intraligamentary Stabilization (DIS) is a technique for the repair of acute anterior cruciate ligament (ACL) injuries. The purpose of this study was to investigate the potential challenges of ACL reconstruction (ACLR) following failure of DIS.MethodsA retrospective analysis of patients with failure of primary ACL repair performed with DIS was undertaken. Failure was defined as abnormal knee laxity (positive Lachman and/or pivot shift) and/or severely restricted range of motion. Medical and surgical records were reviewed and preoperative standard anteroposterior and lateral X-rays were assessed.ResultsBetween July 2015 and May 2022, 10 patients (3 males, 7 females, median age 28 years, range 18–52 years) with failure of DIS were referred to and surgically treated at a single centre. In four patients, single-stage ACLR was performed following the removal of the tibial monoblock. In six patients, arthrofibrosis and excessive tibial tunnel enlargement following the removal of the monoblock prevented single-stage ACLR. These patients underwent arthroscopic arthrolysis and tibial tunnel bone grafting as a first-stage revision procedure.ConclusionIn the present case series, single-stage ACLR was performed in only four (40%) of ten patients following failure of ACL repair with DIS. Arthrofibrosis and excessive tibial tunnel enlargement following the removal of the monoblock prevented single-stage ACLR in six (60%) patients. It is important for clinicians to inform patients that, in the event of failure of ACL repair with DIS, they may run a high risk of undergoing two-stage ACLR.Level of EvidenceLevel IV, Case Series.

Anatomical characteristics and potential gene mutation sites of a familial recurrent patellar dislocation

BackgroundRecurrent patellar dislocation is the result of anatomical alignment and imbalance of restraint of bone and soft tissue. We investigate the anatomical characteristics of the knee joint in a family of patients with recurrent patella dislocation, and to screen the possible pathogenic genes in this family by whole exome sequencing in 4 patients and 4 healthy subjects, so as to provide theoretical basis for the pathogenesis of this disease.MethodsThe data related to patella dislocation were measured by imaging data. The peripheral blood DNA of related family members was extracted for the whole exome sequencing, and then the sequencing results were compared with the human database. By filtering out synonymous variants and high-frequency variants in population databases, and then integrating single nucleotide non-synonymous variants of family members, disease-causing genes were found.ResultsAll patients in this family have different degrees of abnormal knee anatomy, which is closely related to patella dislocation. The sequencing results of patients and normal persons in this patella dislocation family were compared and analyzed, and the data were filtered through multiple biological databases. Find HOXB9 (NM_024017.4:c.404A>G:p.Glu135Gly),COL1A1(NM_000088.3:c.3766G>A:p.Ala1256Thr),GNPAT(NM_014236.3:c1556A>G:p.Asp519Gly),NANS(NM_018946.3:c.204G>C:p.Glu68Asp),SLC26A2(NM_000112.3:c.2065A>T:p.Thr689Ser) are nonsynonymous variants (MISSENSE). Through Sanger sequencing, the identified mutations in HOXB9 and SLC26A2 genes were only present in samples from patients with recurrent patellar dislocation.ConclusionsThe patients with recurrent patellar dislocation had markedly abnormal knee anatomy in this family. HOXB9 gene and SLC26A2 gene were found to be the possible pathogenic genes or related genes for patella dislocation.

Criterion Validity and Reliability of Knee Frontal Plane Projection Angles Measured Using the Technique Application.

Abnormal knee frontal plane projection angles (FPPA) during movement have been associated with patellofemoral pain. As such, clinicians are interested in valid and reliable instruments suitable for broad-based clinical use that allow them to objectively measure such variables. Therefore, the purpose of the current study was to examine the criterion validity and reliability of knee FPPA measures obtained by clinicians using a free tablet application called Technique. Validity/reliability study. To examine validity, the same raters measured 10, two-dimensional criterion reference angles at the first testing session. To examine reliability, the knee FPPA of 16 subjects was measured by 6 raters (3 physical therapists and 3 student physical therapists) on 2 separate occasions while performing a single-limb step-down task. Validity was investigated by calculating the 95% limits of agreement, mean absolute differences, and Bland-Altman plots. Reliability was examined by calculating intraclass correlation coefficients and the SE of measure. For validity, the mean absolute difference between rater and criterion reference angle measures ranged from 0.20° to 0.90°. Ninety-five percent of expected errors between rater and criterion reference angle measures were 2.04° or less. For reliability, the intraclass correlation coefficient values for interrater and intrarater reliability were excellent ranging from .994 to .998 with SE of measure ranging from 0.44° to 0.84°. These findings indicate that knee FPPA measures obtained during a single-limb step-down task using the Technique tablet application are valid and reliable, and suitable for clinical use.

Differences between men and women in coupled subtalar and tibiofemoral joint kinematics during gait revealed through dynamic biplane radiography

It has been suggested that subtalar and tibiofemoral kinematics are coupled, such that abnormal subtalar inversion during the impact and push-off portions of stance may affect tibial rotation, leading to abnormal compensatory knee motion. This study aimed to characterize tibiofemoral and subtalar coupled motion and to determine if sex-dependent differences exist in lower extremity coupled motion. Twenty young adults were imaged at 100 frames/s using dynamic biplane radiography while walking. Lower extremity CT scans were obtained and segmented into subject-specific 3D bone models. Digitally reconstructed radiographs generated from the models were matched to the biplane radiographs via a validated tracking process to obtain tibiofemoral and subtalar joint kinematics. Subtalar inversion/eversion was strongly associated with tibiofemoral internal/external rotation and tibiofemoral ab/adduction during impact and push-off (P < 0.001). Men reached neutral subtalar and tibiofemoral orientation at midstance, while women remained more inverted at the subtalar joint and more externally rotated at the tibiofemoral joint. The rate of tibiofemoral ab/adduction to subtalar eversion differed between sexes during push-off (P = 0.005). Women underwent subtalar inversion, as well as tibiofemoral internal rotation and adduction during push-off, while men underwent only subtalar inversion and tibiofemoral internal rotation, with effectively no tibiofemoral adduction. These results provide the first quantitative evidence characterizing subtalar and tibiofemoral coupled motion. Differences in coupled motion trajectories between men and women may be associated with the higher incidence of knee-related pathology in women. These novel findings may serve as a standard for comparison when evaluating patients with patellofemoral pain.

Three-Way Group Decisions with Incomplete Spherical Fuzzy Information for Treating Parkinson’s Disease Using IoMT Devices

As Internet of Things (IoT) is extensively employed in diverse realistic areas, it is vital to effectively and timely analyze the data collected by IoT devices. To cope with this problem, by integrating adjustable MG SF probabilistic rough sets (PRSs) with the TODIM (an acronym in Portuguese of interactive and multi-criteria decision-making) method, this paper explores a three-way multi-attribute group decision-making (MAGDM) approach in the context of multigranulation (MG) spherical fuzzy (SF) incomplete information systems (IISs) and further applies the presented method to the analysis of leg muscle data obtained from Internet of Medical Things (IoMT) devices for Parkinson’s patients. First, the concept of MG SF IISs is established, and the completion method is provided. Then, adjustable MG SF PRSs are proposed for information fusion. Afterwards, considering the bounded rationality of decision-makers (DMs), a new three-way MAGDM method is designed by fusing adjustable MG SF PRSs with the TODIM method. Finally, in the context of IoMT-based detecting abnormal knee joints in Parkinson’s patients, the applicability and validity of the presented method are eventually verified.

A ResNet50-Based Approach to Detect Multiple Types of Knee Tears Using MRIs

The recommended tool for assessing knee injury is magnetic resonance imaging (MRI). However, knee MRI interpretation takes time and is vulnerable to clinical errors and inconsistency. A deep learning automated technique for reading knee MRI might help physicians identify high-risk patients and make diagnosis easier. In this study, we have proposed a deep learning-based model to detect ACL and meniscus tears and other knee abnormalities. At its core, this model is based on the ResNet50 transfer learning technique. In this paper, we have focused to present a ResNet50-based model for detecting different knee problems using MRIs. The best models for every option achieved the objectives that were probably similar. The models were developed using 18, 3, and 1 slice. These models’ outcomes were rather startling. The AUC findings obtained with 1 slice per MRI exam were equivalent to those obtained with 18 and 3 slices and, in some cases, were significantly better. The dataset used in this model is from Stanford University. We trained this model in three different settings of MRI slices (18, 3, and 1). The best results that our models were able to achieve were when trained using 3 slices of each MRI sample. The area under the receiver operating characteristic curve, or AUC curve, values that our best models were able to achieve for detecting ACL, meniscus, and other knee abnormalities are 0.87, 0.82, and 0.90, respectively. The results of our models are comparable to some state-of-the-art models. These models are very fast and efficient to train and hence will be helpful to doctors for making an effective and fast diagnosis based on knee MRIs.

Congenital dislocation of the knee with bilateral absence of the fibula and suspected Apert syndrome – case report

Congenital dislocation of the knee is a rare deformity, with an unknown etiology. The treatment of this malformation depends on its extensiveness and applies both conservative approach and surgical procedures. The aim of this study is to evaluate treatment outcomes obtained in the patient with congenital dislocation of the right knee and other multiple abnormalities of the motor system as well as the suspicion of Apert syndrome. Between 2005 and 2019, patient with congenital knee dislocation was treated surgically in two medical centers. Authors performed a retrospective analysis of available data from medical archives. The patient first presented to the authors of this study at the age of nine months. Imaging diagnostics revealed complete luxation of the right knee, grade III according to Leveuf and club feet with no fibula bones in the lower legs. The objective of the multi-stage surgical treatment was to enable the patient to walk. Stage one involved a reposition of the congenital right knee dislocation following the Curtis and Fisher technique. The next stage involved a foot surgery – first the left one and then the right. At the age of 5, during the follow-up, the patient was very active: he kept walking, running and jumping and both his feet were in the right position. However, in the following year, a gradual increase of rotation disorders was observed in both lower legs. When the child was 6 years, he underwent derotation osteotomies in both tibia bones. Next, at the age of 12, he underwent anterior femoral hemiepiphysiodesis around right knee with two 8-plates. Plates were removed when he was 14. The last follow-up took place when the patient was 14. The patient is 100% able-bodied and can walk on his own. To sum up, patients with congenital knee dislocation make up a highly complex group that requires multidisciplinary care and frequently also multistage treatment.

Time Difference Between Onsets of Lateral and Medial Hamstring Muscles During Gait in Patients With Patellofemoral Pain: A Preliminary Study

Objective: Early activation of lateral hamstrings (LH) relative to medial hamstrings (MH) has been thought to be the cause of abnormal knee abduction and external rotation of the tibia, which affects the orientation of patellar tendon and increases lateral patellofemoral compression. Therefore, early activation of LH relative to MH is considered to have a role in the patellofemoral pain (PFP). The aim of this study was to investigate the time difference between MH and LH onsets in patients with PFP during gait. Methods: Thirteen patients with bilateral PFP (mean age 28.73±7.44 years) and 13 asymptomatic subjects (mean age 30.47±6.22 years) were recruited in the study. Gait analysis was performed using the ELITE system (BTS, Milano-Italy) with video cameras (TVC, BTS, Milano-Italy). Participants were requested to walk at a self-selected speed on a force platform, and EMG data were recorded from MH and LH muscles for 10 initial contacts by using TELEEMG (BTS, Milano-Italy). Time difference between the onsets of the MH and LH was calculated for each initial contact by using moving averaging method, then their mean was obtained for each participant. Results: The time difference between onsets of MH and LH was – 26.9±22.2 ms for PFP subjects and – 11.2±14.2 ms for control subjects, and LH mainly became activated earlier compared to MH in most of the subjects in both groups. There was a statistically significant difference between the time differences of the groups (p=0.041). Conclusion: Our findings suggest that LH displayed an earlier activation in subjects with PFP compared to control subjects during gait.

3D CAIPIRINHA SPACE versus standard 2D TSE for routine knee MRI: a large-scale interchangeability study.

To perform a large-scale interchangeability study comparing 3D controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) sampling perfection with application optimized contrast using different flip angle evolutions (SPACE) TSE with standard 2D TSE for knee MRI. In this prospective study, 250 patients underwent 3 T knee MRI, including a multicontrast 3D CAIPIRINHA SPACE TSE (9:26 min) and a standard 2D TSE protocol (12:14 min). Thirty-three (13%) patients had previous anterior cruciate ligament and/or meniscus surgery. Two radiologists assessed MRIs for image quality and identified pathologies of menisci, ligaments, and cartilage by using a 4-point Likert scale according to the level of diagnostic confidence. Interchangeability of the protocols was tested under the same-reader scenario using a bootstrap percentile confidence interval. Interreader reliability and intermethod concordance were also evaluated. Despite higher image quality and diagnostic confidence for standard 2D TSE compared to 3D CAIPIRINHA SPACE TSE, the protocols were found interchangeable for diagnosing knee abnormalities, except for patellar (6.8% difference; 95% CI: 4.0, 9.6) and trochlear (3.6% difference; 95% CI: 0.8, 6.6) cartilage defects. The interreader reliability was substantial to almost perfect for 2D and 3D MRI (range κ, 0.785-1 and κ, 0.725-0.964, respectively). Intermethod concordance was almost perfect for all diagnoses (range κ, 0.817-0.986). Multicontrast 3D CAIPIRINHA SPACE TSE and standard 2D TSE protocols perform interchangeably for diagnosing knee abnormalities, except for patellofemoral cartilage defects. Despite the radiologist's preference for 2D TSE imaging, a pursuit towards time-saving 3D TSE knee MRI is justified for routine practice. • Multicontrast 3D CAIPIRINHA SPACE and standard 2D TSE protocols perform interchangeably for diagnosing knee abnormalities, except for patellofemoral cartilage defects. • Radiologists are more confident in diagnosing knee abnormalities on 2D TSE than on 3D CAIPIRINHA SPACE TSE MRI. • Despite the radiologist's preference for 2D TSE, a pursuit towards accelerated 3D TSE knee MRI is justified for routine practice.

Superimposition of ground reaction force on tibial-plateau supporting diagnostics and post-operative evaluations in high-tibial osteotomy. A novel methodology

BackgroundA fully personalised combination of Gait Analysis (GA), including Ground Reaction Force (GRF), and patient-specific knee joint morphology has not yet been reported. This can provide valuable biomechanical insight in normal and pathological conditions. Abnormal knee varus results in medial knee condylar hyper-compression and osteoarthritis, which can be prevented by restoring proper condylar load distribution via High Tibial Osteotomy (HTO). Research questionThis study was aimed at reporting on an original methodology, merging GA, GRF and Computer-Tomography (CT) to depict a patient-specific representation of the knee mechanical condition during locomotion. It was hypothesised that HTO results in a lateralized pattern of GRF with respect to the tibial plateau. MethodsFour patients selected for HTO received clinical, radiological and instrumental examinations, pre- and post-operatively at 6-month follow-up. GA was performed during level walking and more demanding motor tasks using a 9-camera motion-capture system, combined with two force platforms, and an established protocol. Additional skin markers were positioned around the tibial-plateau rim. Weight-bearing CT scans of the knee were collected while still wearing these markers. Proximal tibial and marker morphological models were reconstructed. The markers from CT reconstruction were then registered to the corresponding trajectories as tracked by GA data. Resulting registration matrices were used to report GRF vectors on the plane best matching the tibial-plateau model and the intersection paths were calculated. Results and significanceThe registration procedure was successfully executed, with a max registration error of about 3 mm. GRF intersection paths were found medially to the tibial plateau pre-op, and lateralized post-op, thus much closer to the knee centre, as expected after HTO. The exploitation of the present methodology offers personalised quantification of the original mechanical misalignment and of the effect of surgical correction which could enhance diagnostics and planning of HTO as well as other knee treatments.

Detection and Classification of Knee Injuries from MR Images Using the MRNet Dataset with Progressively Operating Deep Learning Methods

This study aimed to build progressively operating deep learning models that could detect meniscus injuries, anterior cruciate ligament (ACL) tears and knee abnormalities in magnetic resonance imaging (MRI). The Stanford Machine Learning Group MRNet dataset was employed in the study, which included MRI image indexes in the coronal, sagittal, and axial axes, each having 1130 trains and 120 validation items. The study is divided into three sections. In the first section, suitable images are selected to determine the disease in the image index based on the disturbance under examination. It is also used to identify images that have been misclassified or are noisy and/or damaged to the degree that they cannot be utilised for diagnosis in the first section. The study employed the 50-layer residual networks (ResNet50) model in this section. The second part of the study involves locating the region to be focused on based on the disturbance that is targeted to be diagnosed in the image under examination. A novel model was built by integrating the convolutional neural networks (CNN) and the denoising autoencoder models in the second section. The third section is dedicated to making a diagnosis of the disease. In this section, a novel ResNet50 model is trained to identify disease diagnoses or abnormalities, independent of the ResNet50 model used in the first section. The images that each model selects as output after training are referred to as progressively operating deep learning methods since they are supplied as an input to the following model.

Voting-based 1D CNN model for human lower limb activity recognition using sEMG signal.

Surface electromyography (sEMG) signal classification has many applications such as human-machine interaction, diagnosis of kinesiological studies, and neuromuscular diseases. However, these signals are complicated because of different artifacts added to the sEMG signal during recording. In this study, a multi-stage classification technique is proposed for the identification of distinct movements of the lower limbs using sEMG signals acquired from leg muscles of healthy knee and abnormal knee subjects. This investigation involves 11 subjects with a knee abnormality and 11 without knee abnormality for three distinct activities viz. walking, leg extension from sitting position (sitting), and flexion of the leg (standing). Discrete wavelet denoising to fourth level decomposition has been implemented for the artifact reduction and the signal has been segmented using overlapping windowing technique. A study of four different architectures of 1D convolutional neural network models is undertaken for the prediction of lower limb activities and the final prediction is achieved via a voting mechanism of all four model results. The performance parameters of CNN models have been calculated for three different cases: (1) healthy subjects (2) subjects with knee abnormality (3) Pooled data (combination of abnormal knee and healthy knee subjects) using nested threefold cross-validation. It has been found that the voting mechanism yields an average classification accuracy as 99.35%, 97.63%, and 97.14% for healthy subjects, knee abnormal subjects, and pooled data, respectively. The result validates that the proposed voting-based 1D CNN model is efficient and useful in lower limb activity recognition using the sEMG signal.

Ankle foot orthosis that prevents slippage for tibial rotation in knee osteoarthritis patients.

Knee osteoarthritis (OA) is a disease caused by age-related muscle weakness, obesity, or sports injury that leads to gait disability due to pain during walking. Knee OA is characterized by abnormal knee joint alignment and rotational dyskinesia, which are believed to worsen the symptoms. We previously developed an ankle orthosis that mechanically induces the rotation of the lower limb in conjunction with that of the ankle joint. This orthosis can effectively correct the alignment of the knee joint. However, slippage between the orthosis and leg can occur during walking, decreasing the corrective force. In this study, we clarify the effect of slippage between the orthosis and body on the correction force of the orthosis, and develop a lower leg tracking mechanism to suppress slippage and minimize reduction of force. The effectiveness of the proposed mechanism was evaluated by three-dimensional motion analysis of gait. Analysis results confirmed that the proposed mechanism was effective in suppressing slippage and improving correction force, demonstrating the effectiveness of the mechanism for knee OA.