Knee Ankle Research Articles

The effect of dual-task on jump landing kinematics and kinetics in female athletes with or without dynamic knee valgus

It has been indicated that dual tasks may multiply the possibility of injuries due to divided attention. This study aimed to investigate the effect of dual-task on kinematics and kinetics of jump landing in female athletes with and without dynamic knee valgus. In this study, 32 recreational athletes between 18 and 30 years old were recruited and divided into with (n = 17) and without (n = 15) dynamic knee valgus groups. The 3-D positions of retroreflective markers were recorded at 200 Hz using a 8-camera Kestrel system (Motion Analysis Corporation, Santa Rosa, CA), while ground reaction forces were synchronously recorded at 1000 Hz using 2 adjacent force plates (FP4060-NC; Bertec Corporation, Columbus, OH). Kinematics and kinetics of jump landing were recorded while counting backward digits as a dual task, and also without counting backward digits as a single task. One-way repeated measures of variance were used to analyse data at the significant level of 95% (α < 0.05). The study found that the dual-task affected the angles and moments of hip, knee, and ankle joints (P < 0.05) in both groups. Additionally, the effect of the dual-task differed significantly between the two groups in the angles hip flexion (P < 0.001), knee abduction (P < 0.001), and ankle internal rotation (P = 0.001), as well as the moments hip flexion (P < 0.001), hip abduction (P = 0.011), knee flexion (P = 0.017), knee internal rotation (P < 0.001), ankle dorsiflexion (P = 0.046), ankle eversion (P < 0.001), and ankle internal rotation (P = 0.046). Athletes with dynamic knee valgus may have been less able to protect themselves during the landing and are more prone to lower extremities injuries. As a result, using kinematics and kinetics in athletes with dynamic knee valgus during landing may help identify potential mechanisms associated with risk factors of lower extremity injuries and ACL injuries as well.

Pre-injury Knee and Ankle Mechanics During Running are Reduced Among Collegiate Runners who Develop Achilles Tendinopathy.

Achilles tendinopathies (AT) are common in runners, but prospective data assessing running mechanics associated with developing AT are limited. Asymmetry in running mechanics is also considered a risk factor for injury, though it is unknown if the problematic mechanics occur on the injured limb only or are present bilaterally. To prospectively identify differences in pre-injury running biomechanics in collegiate runners who did and did not develop AT and determine if between-limb asymmetries were associated with which limb developed AT. Running gait data were obtained pre-season on healthy collegiate cross country runners, and AT incidence was prospectively recorded each year. Spatiotemporal, ground reaction forces, and joint kinematics and kinetics were analyzed. Linear mixed effects models assessed differences in biomechanics between those who did and did not develop AT during the subsequent year. Generalized linear mixed effects models determined if the asymmetry direction was associated with which limb developed an AT, with odds ratios (OR) and 95% confidence intervals [95% CI] reported. Data from 106 runners were analyzed and 15 developed AT. Pre-injury biomechanics of runners who developed AT showed less peak knee flexion (non-injured: 45.9 degrees [45.2, 46.6], injured: 43.2 degrees [41.5, 44.9], p < 0.001), ankle dorsiflexion (non-injured: 28.7 degrees [28.0, 30.2], injured: 26.0 degrees [23.8, 28.3], p = 0.01), and knee extensor moment (non-injured: -2.18 Nm/kg [-2.24, -2.12], injured: -2.00 Nm/kg [-2.17, -1.84], p = 0.02). The limb demonstrating less peak knee flexion had a greater odds of sustaining an AT (OR = 1.29 [1.00, 1.65], p = 0.05). Knee and ankle kinematics, in addition to knee kinetics, were associated with developing an AT. Monitoring these mechanics may be useful for prospectively identifying runners at risk of developing AT.

Effects of whole-body vibration training combined with KAATSU training on lower limb joint muscle strength in older women.

Objective: This study aimed to investigate the effect of whole-body vibration training (WBVT) combined with KAATSU training (KT) on lower limb joint muscle strength and to provide a reference for improving muscle strength in older women. Methods: A total of 86 healthy older people was randomly divided into WBVT group (WG, n = 21), KT group (KG, n = 22), combined intervention group (CIG, n = 20) and control group (CG, n = 23). WG and CIG subjects underwent WBVT, and KG and CIG subjects underwent 150mmHg and lower limb joint and local compression intervention for 16 weeks (three times per week, about 15min/time). The peak torque (PT) and endurance ratio (ER) of joint flexion or extension were tested for all subjects. Results: 1) Results at 16weeks were compared with the baseline data. The knee extension and ankle flexion PT (60°/s) in CIG increased by 14.3% and 15.3%, respectively (p < 0.05). The knee extension PT (180°/s) increased by 16.9, 18.4% and 33.3% in WG, KG and CIG (p < 0.05), respectively, and the ankle extension PT (180°/s) in CIG increased by 31.1% (p < 0.05). The hip, knee extension and ankle flexion ER increased by 10.0, 10.9% and 5.7% in CIG (p < 0.05), respectively. 2) Results were compared among groups at 16 weeks. The relative changes were significantly lower in WG, KG and CG compared to CIG in the knee extension and ankle flexion PT (60°/s) (p < 0.05). The relative changes were significantly greater in WG, KG and CIG compared to CG in the knee extension PT (180°/s) (p < 0.05). The relative changes were significantly lower in WG, KG and CG compared to CIG in the ankle extension PT (180°/s) (p < 0.05). The relative changes were significantly lower in WG, KG and CG compared to CIG in the hip extension ER (p < 0.05). The relative changes were significantly lower in CG compared to CIG in the knee extension ER (p < 0.05). Conclusion: Sixteen-week WBVT and KT increased the knee extensor strength in older women. Compared with a single intervention, the combined intervention had better improvements in the knee extensor and ankle flexor and extensor strength and hip extension muscle endurance. Appears to be some additional benefit from combined intervention above those derived from single-interventions.

Evaluation of clinical factors associated with early postoperative physical function and lower extremity functional impairment in patients with soft tissue sarcoma

Purpose This study aimed to investigate the relationship between various clinical factors and physical function in the early postoperative period in patients with soft tissue sarcomas (STSs) by subjective and objective evaluations. Materials and Methods The 90 patients enrolled in this study were classified into five groups according to tumor location: retroperitoneal, gluteal, groin, thigh, and lower leg. The Musculoskeletal Tumor Society (MSTS) score was evaluated at discharge; the timed up-and-go test (TUGT) was performed preoperatively and at discharge. Group comparisons by tumor location were performed. To identify significant factors associated with physical dysfunction, multivariate analysis was performed using an MSTS score of <80% and a change in pre and postoperative TUGT score. Results There were no significant differences between the tumor location and physical function. The change in pre- and postoperative TUGT scores was significantly associated with an MSTS score of <80%. Quadriceps and tibialis anterior muscle resections were significantly associated with the change in pre- and post-operative TUGT scores. Conclusions The quadriceps and tibialis anterior muscles may affect physical dysfunction after surgery for STSs. Early postoperative rehabilitation should include the identification of resected muscles and functional improvement of residual muscles, possibly with orthotic support for knee extension and ankle dorsiflexion.

Rotational alignment of the lower extremity in the presence of total knee endoprosthesis: Reproducibility of torsion analyses using ultra-low-dose photon-counting CT

PurposeLeg torsion analysis can provide valuable information in symptomatic patients after total knee arthroplasty. However, extensive beam-hardening and photon-starvation artifacts limit diagnostic assessability and dose reduction potential. For this study, we investigated the reproducibility of rotational measurements in ultra-low-dose photon-counting CT with spectral shaping via tin prefiltration. Material and methodsEmploying a first-generation photon-counting CT, eight cadaveric specimens were examined with an established three-level scan protocol (hip: Sn 140, knee: Sn 100, ankle: Sn 100 kVp). In three body donors with unilateral knee endoprostheses, additional modified settings were applied (Sn 140 kVp at knee level). Protocols were executed with three dose levels (hip–knee–ankle, high-quality: 5.0–3.0–2.0 mGy, low-dose: 0.80–0.30–0.26 mGy, ultra-low-dose: 0.25–0.06–0.06 mGy). Six radiologists performed torsion analyses, additionally reporting their diagnostic confidence. Intraclass correlation coefficients (ICC) were calculated to assess interrater reliability. ResultsNo significant differences were ascertained for femoral (p = 0.330), tibial (p = 0.177), and overall leg rotation measurements (p = 0.358) among high-quality, low-dose, and ultra-low-dose protocols. Interrater reliability was excellent for torsion of the femur (ICC 0.915, 95% confidence interval 0.871–0.947), tibia (0.960, 0.938–0.976), and overall leg (0.967, 0.945–0.981). In specimens with total knee endoprostheses, absolute rotational measurements were unaffected by dose level and tube voltage despite superior diagnostic confidence on the ipsilateral and contralateral sides with modified settings (p < 0.001). ConclusionsCombining the advantages of photon-counting CT and spectral shaping, reliable leg torsion analyses are feasible with ultra-low radiation exposure even in the presence of total knee endoprostheses.

Analysis of inter-joint coordination during the sit-to-stand and stand-to-sit tasks in stroke patients with hemiplegia

BackgroundInter-joint coordination is an important factor affecting postural stability, and its variability increases after fatigue. This study aimed to investigate the coordination pattern of lower limb joints during the sit-to-stand (Si-St) and stand-to-sit (St-Si) tasks in stroke patients and explore the influence of duration on inter-joint coordination.MethodsThirteen stroke hemiplegia patients (five with left paretic and eight right paretic) and thirteen age-matched healthy subjects were recruited. The Si-St and St-Si tasks were performed while each subject’s joint kinematics were recorded using a three-dimensional motion capture system. Sagittal joint angles of the bilateral hip, knee and ankle joints as well as the movement duration were extracted. The angle-angle diagrams for the hip-knee, hip-ankle and knee-ankle joint were plotted to assess the inter-joint coordination. The inter-joint coordination was quantified using geometric characteristics of the angle-angle diagrams, including perimeter, area and dimensionless ratio. The coefficient of variation (CV) was performed to compare variability of the coordination parameters.ResultsThere were no significant differences in the perimeter, area and dimensionless ratio values of the bilateral hip-knee, hip-ankle and knee-ankle inter-joints during Si-St and St-Si tasks in the stroke group. The perimeter values of bilateral hip-knee and knee-ankle inter-joints in the stroke group were lower (P<0.05) than in the healthy group during Si-St and St-Si tasks. Although no significant bilateral differences were found, the inter-joint coordination in stroke patients decreased with the increased movement duration of both Si-St and St-Si tasks. Additionally, the CV of the hip-knee inter-joint area during the Si-St task in the stroke group was less than (P<0.05) that in the healthy group.ConclusionStroke patients exhibit different inter-joint coordination patterns than healthy controls during the Si-St and St-Si tasks. The duration affects joint coordination, and inter-joint coordination is limited on the hemiplegic side joint pairs, which may lead to inconsistency in the rhythm of the left and right leg inter-joint movements and increase the risk of falls. These findings provide new insights into motor control rehabilitation strategies and may help planning targeted interventions for stoke patients with hemiplegia.

E66 Arthropathy as the initial presentation of HIV

Abstract Background Human immunodeficiency virus (HIV) has been associated with musculoskeletal disorders which has been estimated to occur in 11–72% of infected patients. Most of these reports however have been in adults with few published cases of HIV associated arthritis in children. The articular manifestations of HIV, especially overt arthritis, can occur at any stage of the disease but are more prevalent in advanced immunosuppression. With the increased access to early diagnosis and highly active antiretroviral therapy (HAART), such complications have increasingly become rare. However, HIV diagnosis may often be missed or delayed in slow progressors, and in such circumstances, these patients may manifest with arthritis as the initial manifestation of HIV. Therefore, there’s need for consideration of HIV associated arthritis in children presenting with arthropathy of undetermined cause. We hereby present a case of arthritis as the initial manifestation of HIV in a child with missed diagnosis of HIV. Methodology/case presentation A 12-year-old boy was admitted in the Kenyatta National Hospital (KNH) paediatric ward with a history of joint pain and swelling for three months. He had otherwise previously been well. He had no history of fever, trauma, preceding gastroenteritis or urine tract infection. He had no chorea, no erythematous rash and no cardiac complications of rheumatic fever. He was not wasted, and was able to walk with great difficulty. He had bilateral knee and right ankle swelling. The swollen joints were warm to touch with positive ballotment and fluid sweep test. Joint aspiration revealed straw coloured joint effusion. Investigations included a positive HIV rapid test with CD4% of 6, CRP 8.33 mg/l (n = &amp;lt;5), Elevated ESR (111 mm in first h) and negative ANA. Bilateral Knee -rays did not reveal any destructive or erosive changes. A diagnosis of HIV arthropathy was made and the patient was started on HAART, HCQ, prednisone and ibuprofen. He improved, with resolution of the joint swellings, was discharged home after 10 days and follow up in the rheumatology and comprehensive care clinics advised. Conclusion HIV arthropathy should be considered in patients manifesting with arthritis of unknown origin; and the patients evaluated for HIV as a strategy for identifying and including them in care. Highly active antiretroviral therapy, steroids, hydroxychloroquine and NSAIDS may be effective therapy for HIV arthropathy. Disclosure statement: The authors have no conflict of interest to declare.

Kinematic and mechanical alignments in total knee arthroplasty: A meta-analysis with ≥1-year follow-up

BackgroundKinematic and mechanical alignment outcomes in total knee arthroplasty remain controversial. This study compared the clinical and radiological outcomes of total knee arthroplasty using kinematic and mechanical alignments. MethodsWe systematically searched PubMed, EMBASE, Web of Science, and Cochrane Library databases for randomized controlled trials and cohort studies published before November 2022. The data of interest were extracted and analyzed using Review Manager V.5.4. ResultsNineteen randomized controlled trials and cohort studies involving 880 kinematic alignment total knee arthroplasties and 965 mechanical alignment total knee arthroplasties were included. In this meta-analysis, the kinematic alignment group achieved better knee joint function scores, including the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, and Knee Society Score, and better flexion angles. No statistical differences were detected in the Western Ontario and McMaster Universities Osteoarthritis Index, extension angle, Forgotten Joint Score, European Quality of Life five-dimension measure, hip–knee–ankle angle, or complications between the kinematic and mechanical alignment groups. ConclusionThis meta-analysis indicated that kinematic alignment total knee arthroplasty provides clinical benefits in terms of the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, Knee Society Score (knee), Knee Society Score (function), and better flexion angles. In addition, kinematic alignment total knee arthroplasty led to similar clinical outcomes as mechanical alignment total knee arthroplasty without increasing complications. Systematic review registrationhttp://www.crd.york.ac.uk/PROSPERO/CRD42022373227.

Preliminary Results of Measurements of Frontal Plane Knee Alignment Using a Standardized, Sonographic-Assisted Digital Photograph—A Reliable and Accurate Alternative to a Full-Leg Radiograph?

(1) Clinical alternatives to the full-leg radiograph (FLR) for determining frontal plane lower limb alignment have shown mixed results so far concerning reliability and accuracy. In addition, intercondylar respectively intermalleolar distance (ICD/IMD) measurement is limited in the interpretation of its results. The purpose of the study is to present a standardized, sonographic-assisted photographic measurement (SPM) of the leg axis in the frontal plane using a digital photograph and compare it with the gold standard of the anterior–posterior FLR. (2) Adults who had recently received an FLR were included in the study. After determining the center of the hip joint and knee joint gap in a standing position via ultrasound, a standardized digital photograph was taken. Subsequently, the hip–knee–ankle angle (HKA) was measured using an image editing program for SPM and FLRs. Mean deviation (MD), Pearson’s correlation coefficient and the clinical method’s interclass correlation coefficient (ICC) were calculated. (3) Of 18 subjects (8 male and 10 female), respectively, 34 lower extremities have been included in the study. Their mean BMI was 25.5 kg/m2. The correlation between the two measurement methods for subjects with BMI &lt; 30 kg/m2 was reliably high (r = 0.93, p &lt; 0.001). The HKAs derived from SPM and FLRs showed a mean deviation (MD) of 2.4° (range 0.1–6.0°) for subjects with BMI &lt; 30 kg/m2. The average ICC among all examiners conducting the SPM was 0.99 (CI 0.95–0.99, p &lt; 0.001). The MD for subjects ≥ 30 kg/m2 increased significantly (MD = 5.5°; n = 10, p &lt; 0.001). (4) SPM of the leg axis in the frontal plane allows sufficiently accurate results in patients with a BMI lower than 30 kg/m2. The methodology is limited in cases of increased BMI and needs well-trained examiners. Nevertheless, as a screening method in the field of children and adolescents, this method can be recommended in clinical daily routine.

Cross-Cultural Adaptation of the University of Wisconsin Running Injury and Recovery Index in Turkish Runners.

The University of Wisconsin Running Injury and Recovery Index (UWRI) was developed to evaluate the key elements that runners use to self-assess their own running ability following common running-related injuries. The aim of this study was to translate and culturally adapt the UWRI and to evaluate the psychometric properties of its Turkish version (UWRI-Tr) in runners. Prospective cohort study. The study included 129 runners. The UWRI-Tr, the Lower Extremity Functional Scale, the Oswestry Disability Index, the Hip Outcome Score, the International Knee Documentation Committee Subjective Knee Evaluation Form, and the Foot and Ankle Ability Measure were applied for the validation purposes. Internal consistency, reliability, construct validity, and discriminant validity of the UWRI-Tr were tested. The test-retest reliability of the UWRI-Tr was excellent with an intraclass correlation coefficient of .85 and a Cronbach α value of .84. There was a small to strong correlation among the UWRI-Tr and Lower Extremity Functional Scale (r = .278), Oswestry Disability Index (r = -.744), Hip Outcome Score (r = .684), The International Knee Documentation Committee Subjective Knee Evaluation Form (r = .758), and Foot and Ankle Ability Measure (r = .498 and .767), indicating that its construct validity was appropriate for use with Turkish runners. The UWRI-Tr was shown to be a valid and reliable tool to use in clinical and research settings as a sport-specific measurement tool.

Recombinant factor IX Fc for major surgery in hemophilia B: factor IX plasma activity levels and effective hemostasis

BackgroundMajor surgical procedures are associated with significant bleeding risk and infectious complications in patients with hemophilia, which may be minimized by factor replacement. Monitoring perioperative factor levels guides dosing to maintain adequate levels for hemostatic control. ObjectivesWe report prospectively collected post hoc surgical data in patients with hemophilia B who underwent major surgery with extended half-life recombinant factor IX Fc fusion protein (rFIXFc) in phase 3 studies (B-LONG/Kids B-LONG and B-YOND). MethodsAchieved FIX plasma levels were described for those who underwent major surgeries with ≥1 peak and/or predose FIX assessment available on the day of surgery (Day 0 [D0]) from the central laboratory. Dosing, injection frequency, adverse events, and hemostatic responses were assessed. Two representative cases were described further including blood loss, transfusions, and concomitant medication assessment. ResultsOf 35 major surgeries, 17 (N = 16 subjects) with sufficient FIX measurements were included in this analysis; 13 of 17 surgeries were orthopedic. On D0, a median loading (preoperative) dose of 101.1 International Units (IU)/kg/injection achieved a median peak FIX of 103.3 IU/dL. Across postoperative Days 1 to 3, 4 to 6, and 7 to 14, the median predose levels were 75.1 IU/dL with 1 injection/d, 71.6 IU/dL with 0 to 1 injection/d, and 43.2 IU/dL with 0 to 1 injection/d, respectively. Hemostasis was rated excellent (14 of 16) or good (2 of 16) across surgeries. Both case studies (knee arthroscopy and ankle fusion) illustrate measured FIX levels with rFIXFc. ConclusionThe aggregate analysis and representative cases of major surgeries demonstrate that rFIXFc can achieve FIX levels for effective hemostasis during invasive high-risk procedures.

Playing Football as a Risk Factor for Lower Leg Malalignment?—Comparing Lower Leg Axis of Male Adolescent Football Players and Referees

The prevalence of varus knee malalignment among junior and adult football players (FP) has proven to be higher compared to other sports. No causal relationship has yet been found, as genu varum can be assumed to be an independent risk factor for the development of knee osteoarthritis. The purpose of this study is to compare knee alignment measurements and sport-specific data of adolescent football players and referees (REF). Knee alignment was detected by measuring the intercondylar/intermalleolar distance (ICD/IMD) as well as the Hip–Knee–Ankle angle (HKA) using a standardized digital frontal-plane photograph. Anthropometric and sports-related data (training/match exposure, seasons actively played, etc.) were collected by means of questionnaires (Clinical trial registration number: DRKS00020446). A total of 28 male FP and 29 male adolescent REF were included in the survey. The mean age was 17.4 ± 0.7 years. The two groups did not differ significantly in age, height, weight, BMI, and overall football/refereeing exposure per week (FP vs. REF: 274 vs. 285 min/week, p = 0.61). The HKA of the FP was significantly lower (toward varus) than that of the REF (177.6° ± 2.4° vs. 179.0° ± 2.4°; p &lt; 0.001). However, ICD did not significantly differ (FP: 17 ± 25 mm, REF: 13 ± 27 mm; p = 0.55). The football environment with frequent football exposure seems to have an influence on leg axis deviation in FP compared to REF. For prevention of knee osteoarthritis in FP, an advanced understanding of leg axis development in adolescent players is essential and, therefore, needs further research.

Assessing physical abilities of sarcopenia patients using gait analysis and smart insole for development of digital biomarker

The aim of this study is to compare variable importance across multiple measurement tools, and to use smart insole and artificial intelligence (AI) gait analysis to create variables that can evaluate the physical abilities of sarcopenia patients. By analyzing and comparing sarcopenia patients with non sarcopenia patients, this study aims to develop predictive and classification models for sarcopenia and discover digital biomarkers. The researchers used smart insole equipment to collect plantar pressure data from 83 patients, and a smart phone to collect video data for pose estimation. A Mann–Whitney U was conducted to compare the sarcopenia group of 23 patients and the control group of 60 patients. Smart insole and pose estimation were used to compare the physical abilities of sarcopenia patients with a control group. Analysis of joint point variables showed significant differences in 12 out of 15 variables, but not in knee mean, ankle range, and hip range. These findings suggest that digital biomarkers can be used to differentiate sarcopenia patients from the normal population with improved accuracy. This study compared musculoskeletal disorder patients to sarcopenia patients using smart insole and pose estimation. Multiple measurement methods are important for accurate sarcopenia diagnosis and digital technology has potential for improving diagnosis and treatment.

A comparison of neural control of the biarticular gastrocnemius muscles between knee flexion and ankle plantar flexion.

We aimed to determine whether the neural control of the biarticular gastrocnemius medialis (GM) and lateralis (GL) muscles is joint-specific, that is, whether their control differs between isolated knee flexion and ankle plantar flexion tasks. Twenty-one male participants performed isometric knee flexion and ankle plantar flexion tasks while we recorded high-density surface electromyography (HDsEMG). First, we estimated the distribution of activation both within- and between muscles using two complementary approaches: surface EMG amplitude and motor unit activity identified from HDsEMG decomposition. Second, we estimated the level of common synaptic input between GM and GL motor units using a coherence analysis. The distribution of EMG amplitude between GM and GL was not different between tasks, which was confirmed by the analysis of motor units' discharge rate. Even though there was a significant proximal shift in GM and GL EMG amplitude during knee flexion compared with ankle plantar flexion, the magnitude of this shift was small and not confirmed via the inspection of the spatial distribution of motor unit action potentials. A significant coherence between GM and GL motor units was only observed for four (knee flexion) and three (ankle plantar flexion) participants, with no difference in the level of coherence between the two tasks. We were able to track only a few motor units across tasks, which raises the question as to whether the same motor units were activated across tasks. Our results suggest that the neural control of the GM and GL muscles is similar across their two main functions.NEW & NOTEWORTHY Several studies have focused on the neural strategies used to control the gastrocnemius medialis (GM) and lateralis (GL) during plantar flexion. However, their secondary function, i.e., knee flexion, is not often explored. We observed a robustness of the GM and GL activation strategy across tasks, which was confirmed with an analysis of the motor unit discharge characteristics. The level of common synaptic input between GM and GL motor units was low, regardless of the task.

Learning curve and short-term clinical outcomes of a new seven-axis robot-assisted total knee arthroplasty system: a propensity score-matched retrospective cohort study

ObjectiveThe purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted (RA) total knee arthroplasty (TKA) system and to explore whether it could provide superior short-term clinical and radiological outcomes compared with conventional surgery.MethodsIn the present retrospective study, 90 patients who underwent RA-TKA were included in robot-assisted system (RAS) group and 90 patients who underwent conventional TKA were included in the conventional group. The duration of surgery and robot-related complications were recorded to evaluate the learning curve through cumulative sum and risk-adjusted cumulative sum methods. The demographic data, preoperative clinical data, preoperative imaging data, duration of surgery, alignment of the prosthesis, lower limb force line alignment, Knee Society score, 10-cm visual analog scale pain score and range of motion were compared between the RAS and conventional groups. In addition, the proficiency group was compared with the conventional group using propensity score matching.ResultsRA-TKA was associated with a learning curve of 20 cases for the duration of surgery. There was no significant difference in indicators representing the accuracy of the prosthetic installation between the learning and proficiency phases in RA-TKA group patients. A total of 49 patients in the proficiency group were matched with 49 patients from the conventional group. The number of postoperative hip–knee–ankle (HKA) angle, component femoral coronal angle (CFCA), component tibial coronal angle (CTCA), and sagittal tibial component angle (STCA) outliers in the proficiency phase was lower than that in the conventional group, while deviations of the HKA angle, CFCA, CTCA, and STCA in the proficiency phase were significantly lower than those in the conventional group (P < 0.05).ConclusionIn summary, from the learning curve data, 20 cases are required for a surgeon using a novel seven-axis RA-TKA system to enter the proficiency phase. In the proficiency group, compared with the conventional group using propensity score matching, the RAS was found to be superior to the conventional group in prosthesis and lower limb alignment.

Exploring variations in gait patterns and joint motion characteristics in school-aged children across different walking speeds: a comprehensive motion analysis study.

This study aimed to investigate differences in gait patterns among individuals with different walking speeds and identify the range of motion (ROM) and angular velocity for various joints during gait. Forty-five schoolchildren were randomly selected for this study. To capture their walking patterns, two FDR-AX700 4K HDR camcorders were positioned to observe the predetermined walkway. Each participant completed a 5-meter walk at various speeds, including slow, normal, and fast, while maintaining a straight stride. There were significantly higher ROM and angular velocity (p<0.05) at the hip, knee, and ankle joints across most stages of walking at a faster speed compared to slow and normal speeds. At the same time, the angular velocity was significantly higher at the hip joint during hip extension terminal stance at normal speed compared to slow and fast speeds (p<0.05, ƞ2 =0.74). Similarly, the ROM of knee flexion swing, ankle plantar flexion loading response, and ankle dorsiflexion midswing angular velocity were significantly higher during normal walking speed (p<0.05). Conversely, slow-speed walking showed significantly higher ROM at knee extension terminal swing (ƞ2=0.52) and ankle dorsiflexion terminal stance (ƞ2=0.78) (p<0.05). The results indicate that individuals with different walking speeds exhibit significant differences in gait patterns. Slower walking speeds resulted in lower gait velocity and different joint motions compared to faster walking speeds.

The Influence of Knee Extensor and Ankle Plantar Flexor Strength on Single-Leg Standing Balance in Older Women.

Impaired balance is a significant risk factor for falls among older adults. The precise impact of lower-extremity muscles, including the proportion of muscle strength, on the performance of single-leg standing balance tests in older individuals is very interesting. The aim of this study is to examine the correlation between the knee extensor (KE), ankle plantar flexor (AP) muscle strength, and performance in single-leg standing balance tests in older females. Additionally, it aims to evaluate the combined proportion of KE and AP muscle strength in maintaining balance during single-leg standing. A total of 90 older females (mean age 67.83 ± 8.00 years) were recruited. All participants underwent maximum voluntary isometric contraction (MVIC) testing of the KE and AP muscles, as well as single-leg standing balance tests with eyes open (SSEO) and eyes closed (SSEC). To examine the influence of KE and AP muscle strength on balance performance, multiple regression analysis was conducted. Low correlations were found between SSEO and MVIC of KE and AP muscles, but moderate correlations were found with percentage of MVIC to body weight ratio (%MVIC/BW). The best model for SSEO included 0.99 times of the %MVIC/BW of AP and 0.66 times that of KE muscles as independent predictor variables (r = 0.682). In conclusion, AP muscle strength was found to have a greater impact on single-leg standing balance compared with KE muscle strength.

Sex differences in age-related differences in joint motion during gait in community-dwelling middle-age and older individuals

BackgroundWalking is the most important mode of human locomotion; however, the ability to walk often decreases with age. Age-related differences in lower-limb kinematics during gait may differ depending on sex. However, the question of the compounded effects of age and sex on gait kinematics remains unsolved. Research questionThe present study aimed to clarify the interaction between age and sex in differences in gait kinematics of community-dwelling middle-age and older individuals. MethodsThis study included 836 community-dwelling middle-age and older adults (61.8 % female). Joint motion during comfortable gait was measured using magnetic and inertial measurement units. Hip, knee, and ankle joint angles were calculated in the sagittal plane. Participants were divided into four groups according to age: 50–59, 60–69, 70–79, and 80–89 years. The interaction of sex and age on spatiotemporal gait parameters and the peak value of joint angles was analyzed using two-way analysis of variance (ANOVA) and Tukey’s post hoc test. ResultsGait speed (F = 43.92, P < 0.001), step length (F = 73.00, P < 0.001), hip extension (F = 12.89, P = 0.002), knee flexion (F = 39.99, P < 0.001), and ankle plantar flexion (F = 27.43, P < 0.001) significantly decreased with age. Significant differences according to sex were observed in all parameters except gait speed. Significant age and sex interaction effects were observed for knee flexion (F = 4.97, P = 0.002) and ankle dorsiflexion (F = 4.04, P = 0.007). SignificanceA significant interaction effect of age and sex was observed for peak angle of knee flexion and ankle dorsiflexion during gait. In particular, the knee flexion angle among females during gait began to decrease from 60 years of age, and the decreasing trend was faster and more prominent than that among males.

The gap height in open wedge high tibial osteotomy is not affected by the starting point of the osteotomy

IntroductionIn open-wedge high-tibial-osteotomy (OWHTO), most surgeons use a preoperative planning software and realise that they should match the intraoperative alignment correction with the preoperative plan. We aimed to determine whether there is a difference in osteotomy gap height when starting the OWHTO either 3 or 4 cm distal to the joint line. This should help to clarify whether the osteotomy starting point must exactly match the preoperative planning.Methods25 patients with constitutional varus alignment were planned for OWHTO. Long-leg-standing-radiographs and mediCAD-software were used. Osteotomy was planned to a neutral Hip-Knee-Ankle angle (HKA) of 0°. The osteotomy-starting-point was either 3 or 4 cm distal to the medial joint line. The following angles were compared: mechanical medial proximal tibial angle (mMPTA), mechanical lateral distal femoral angle (mLDFA), joint line conversion angle (JCA), mechanical Tibio-Femoral angle (mTFA) or Hip Knee Ankle (HKA) angle.Results25 Patients (18 males, 7 females) had a mean age of 62 ± 16.6 years and showed a varus-aligned leg-axis. The HKA was − 5.96 ± 3.02° with a mMPTA of 82.22 ± 1.14°. After osteotomy-planning to a HKA of 0°, the mMPTA was 88.94 ± 3.01°. With a mean wedge height of 8.08 mm when locating the osteotomy 3 cm and a mean wedge height of 8.05 mm when locating the osteotomy 4 cm distal to the joint-line, there was no statistically significant difference (p = 0.7).ConclusionWhen performing an OWHTO aiming towards the tip of the fibula, the osteotomy starting point does not need to exactly match the planned starting-location of the osteotomy. A starting-point 1 cm more distal or proximal than previously determined through the digital planning does not alter the size of the osteotomy gap needed to produce the desired amount of correction.

Long-term locked knee ankle foot orthosis use: A perspective overview of iatrogenic biomechanical and physiological perils.

A knee ankle foot orthosis (KAFO) may be prescribed to the person with severe neuromusculoskeletal impairment of the lower limb to promote walking stability. The locked knee ankle foot orthosis (L-KAFO) is among the KAFO's routinely prescribed; however, long-term use of the L-KAFO is associated with musculoskeletal (arthrogenic and myogenic) and integumentary changes, and gait asymmetry with increased energy expenditure. Consequently, the risk of developing low back pain, osteoarthritis of the lower limbs and spinal joints, skin dermatitis, and ulceration increases, all of which impact quality of life. This article synthesizes the iatrogenic biomechanical and physiological perils of long-term L-KAFO use. It promotes using recent advances in rehabilitation engineering to improve daily activities and independence for proper patient groups.