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Total ankle prosthesis as a surgical solution in the case of end-stage osteoarthritis has seen a considerable increase in the last two decades. This study protocol arises from the need to understand the in vivo kinematics of mobile-bearing, flat tibial component total ankle replacement, evaluating the real range of motion and the reciprocal relationships between the components during normal motor tasks through the use of model-based radio-stereometric analysis (MB-RSA). In addition, pre- and post-operative evaluation of walking kinematics with inertial motion sensors, proprioception through a dedicated workstation, and clinical outcomes are discussed. We expect that based on our study protocol researchers will be able to improve future prosthetic designs and validate the setup of MB-RSA, as well as to understand "how an ankle prosthesis moves" once implanted in the patient. [ABSTRACT FROM AUTHOR]

A consistent injury mechanism involving multiple joints has been highlighted in athletes experiencing anterior cruciate ligament (ACL) rupture. However, if and to what extent healthy athletes incur an unsafe biomechanical profile during high-dynamics movements is unknown. The present study aimed to investigate the occurrence of the ACL risk profile in a competitive pivoting sports population.Thirty-four athletes (22.8 ± 4.1 y) performed a frontal deceleration and a change of direction at 90°. Full-body kinematics was collected through 15 wearable inertial sensors (Awinda, Xsens). Nine ACL risk factors were defined based on four categories: limited lower limb flexion, valgus collapse, foot rotation and trunk rotation. A movement trial was considered ‘at-risk’ in the presence of at least 5 simultaneous risk factors. The rate of athletes with at-risk movements was assessed and multivariate regression for associated outcomes was conducted.The overall rate of injury profile occurrence was 9–12%. The injury profile was identified at least in one trial in 24 athletes (71%) and three trials in 5 athletes (15%). Significant associations were found for higher approaching speed (OR = 4.3) and female sex (OR = 4.8). A large occurrence of the typical ACL injury biomechanical profile was noticed. Large screenings are advisable to identify at-risk athletes and promote preventative strategies. [ABSTRACT FROM AUTHOR]

Background: Proprioception is one of the most significant factors in balance, joint stability, graceful movement, coordination, and injury prevention. It involves a wide set of receptors located within joints, muscles, and tendons. Given the neurophysiological processes involved in proprioception response are multiple and complex, there is not one single method to measure it. Particularly, proprioception of the knee joint, whether it is healthy, affected by osteoarthritis, or after replacement, is the most investigated by in literature.Research Question: This review addresses the analysis of proprioception in the knee joint before and after total knee arthroplasty (TKA). The aim is to obtain an overview of the proprioceptive skills in subjects who suffered from osteoarthritis and were subjected to knee replacement, evaluating changes in proprioception before and after the surgery.Methods: The research was conducted within four databases: Web of Science®, PubMed Central®, Cochrane®, and PEDro®, between January 2008 and February 2018. Accurate exclusion criteria and selection strategy were applied to screen the 170 articles found.Results: Ultimately, 13 papers were fully evaluated and included in this review, divided into two classes: i) works directly measuring proprioception, ii) studies indirectly evaluating proprioception. Contrasting results emerged from the analysis, and no consensus was found in the literature about the improvement or worsening in proprioception before and after TKA.Significance: Since currently there is high variability in methods, protocol and parameters used to evaluate knee proprioception, further investigations based on a consistent dataset, a well-defined protocol, measurable outcomes, timeline follow-ups, and rehabilitation programs should be performed in order to obtain reliable results on the effects of TKA on knee proprioception and balance. [ABSTRACT FROM AUTHOR]

Purpose: To assess, using model-based dynamic radiostereometric analysis (RSA), the biomechanical behaviour of a new design posterior-stabilized (PS) fixed-bearing (FB) total knee arthroplasty (TKA) in vivo while patients performing two common motor tasks. The hypothesis was that model-based dynamic RSA is able to detect different behaviour of the implant under weight-bearing and non-weight-bearing conditions.Methods: A cohort of 15 non-consecutive patients was evaluated by dynamic RSA 9 months after TKA implantation. The mean age of patients was 73.4 (65-72) years. The kinematic evaluations were performed using an RSA device (BI-STAND DRX 2) developed in our Institute. The patients were asked to perform two active motor tasks: sit-to-stand in weight-bearing condition; range of motion (ROM) while sitting on the chair. The motion parameters were evaluated using the Grood and Suntay decomposition and the low-point kinematics methods.Results: The dynamic RSA evaluation showed a significant difference (p < 0.05) between the biomechanical behaviour of the prosthesis during the two motor tasks. When subjected to the patient weight (in the sit-to-stand) the low point of the medial compartment had a shorter motion (5.7 ± 0.2 mm) than the lateral (11.0 ± 0.2 mm). This realizes a medial pivot motion as in the normal knee. In the ROM task, where the patient had no weight on the prosthesis, this difference was not present: the medial compartment had a displacement of 12.7 ± 0.2 mm, while the lateral had 17.3 ± 0.2 mm.Conclusions: Model-based RSA proved to be an effective tool for the evaluation of TKA biomechanics. In particular, it was able to determine that the fixed-bearing posterior-stabilized TKA design evaluated in this study showed a medial pivoting movement under weight-bearing conditions that was not present when load was not applied. Under loading conditions what drives the pattern of movement is the prosthetic design itself. By the systematic use of this study protocol future comparisons among different implants could be performed, thus contributing significantly to the improvement of TKA design.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

In orthopedic medical devices, differences in elasto-plastic behavior between bone and metallic materials could lead to mechanical issues at the bone-implant interface, such as stress shielding, bone fracture or implant failure. To reduce mismatching-related adverse events between bone and prosthetic mechanical properties, an in-body geometry optimization could be the right approach to reduce prosthetic stiffness. Therefore, this study aims to assess the elastic behavior of four different in-body gap prismatic geometries (quadratic, hexagonal, octagonal, and circular) and how much they reduce bulk stiffness. Uniaxial compression tests were performed on five cubes with a 20 mm thickness, each containing a different set of internal prismatic gaps. For each design, the elastic response was calculated and compared with a full-volume cube, used as control. All cubes showed a stiffness reduction compared to the control, greater in cubes with quadratic (21%), octagonal (18%), and circular (17%) transversal sections, compared to the hexagonal one (6%). Moreover, finite element models were implemented and tested, showing coherent values obtained through the experimental tests. In addition, a bi-material approach was studied in silico and the results suggested that variable elastic behavior could be obtained by using composite material, providing lower mechanical properties than commonly used commercial prosthetic materials. [ABSTRACT FROM AUTHOR]

Purpose: The main purpose of the present study was to determine long-term implant fixation of 15 unicompartmental knee arthroplasty (UKAs) with an all-poly tibial component using Roentgen stereophotogrammetric analysis (RSA) at a mean 10-year follow-up. The secondary purpose was to investigate whether the progressive loss of implant's fixation correlates with a reduction in Knee society score (KSS).Methods: Fifteen non-consecutive patients with primary knee osteoarthritis received a UKA with an all-poly tibial component were assessed using KSS scores pre-operatively and post-operatively and RSA on day 2 after surgery, then at 3, 6, and 12 months and yearly thereafter. The mean last follow-up was 10 years.Results: An increase in maximum total point motion (MTPM) values from 6 months to 1 year post-operatively was found respect to post-operative reference. Implants' displacement values were always <2 mm during the first 6 months, and then, two different trends were noticed in revised and non-revised implants. MTPM increase between 1 and 2 years of follow-up in non-revised UKAs was always <0.2 mm, whereas it was >0.2 mm in revised UKAs. A linear and negative correlation with statistical significance was found between MTPM and both clinical and functional KSS scores (p < 0.001).Conclusion: Also in a long-term follow-up evaluation, RSA is an effective tool to predict functional results after an all-poly UKA providing also a relevant predictive value at 1 year follow-up, and this can be very useful for both patients and surgeons.Level Of Evidence: Diagnostic studies, Level III. [ABSTRACT FROM AUTHOR]

Modifiable (biomechanical and neuromuscular) anterior cruciate ligament (ACL) injury risk factors have been identified in laboratory settings. These risk factors were subsequently used in ACL injury prevention measures. Due to the lack of ecological validity, the use of on-field data in the ACL injury risk screening is increasingly advocated. Though, the kinematic differences between laboratory and on-field settings have never been investigated. The aim of the present study was to investigate the lower-limb kinematics of female footballers during agility movements performed both in laboratory and football field environments. Twenty-eight healthy young female talented football (soccer) players (14.9 ± 0.9 years) participated. Lower-limb joint kinematics was collected through wearable inertial sensors (Xsens Link) in three conditions: (1) laboratory setting during unanticipated sidestep cutting at 40-50°; on the football pitch (2) football-specific exercises (F-EX) and (3) football games (F-GAME). A hierarchical two-level random effect model in Statistical Parametric Mapping was used to compare joint kinematics among the conditions. Waveform consistency was investigated through Pearson's correlation coefficient and standardized z-score vector. In-lab kinematics differed from the on-field ones, while the latter were similar in overall shape and peaks. Lower sagittal plane range of motion, greater ankle eversion, and pelvic rotation were found for on-field kinematics (p < 0.044). The largest differences were found during landing and weight acceptance. The biomechanical differences between lab and field settings suggest the application of context-related adaptations in female footballers and have implications in ACL injury prevention strategies. Highlights Talented youth female football players showed kinematical differences between the lab condition and the on-field ones, thus adopting a context-related motor strategy. Lower sagittal plane range of motion, greater ankle eversion, and pelvic rotation were found on the field. Such differences pertain to the ACL injury mechanism and prevention strategies. Preventative training should support the adoption of non-linear motor learning to stimulate greater self-organization and adaptability. It is recommended to test football players in an ecological environment to improve subsequent primary ACL injury prevention programmes. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate if the presence of anterior cruciate ligament (ACL) injury risk factors depicted in the laboratory would reflect at-risk patterns in football-specific field data. Twenty-four female footballers (14.9 ± 0.9 year) performed unanticipated cutting maneuvers in a laboratory setting and on the football pitch during football-specific exercises (F-EX) and games (F-GAME). Knee joint moments were collected in the laboratory and grouped using hierarchical agglomerative clustering. The clusters were used to investigate the kinematics collected on field through wearable sensors. Three clusters emerged: Cluster 1 presented the lowest knee moments; Cluster 2 presented high knee extension but low knee abduction and rotation moments; Cluster 3 presented the highest knee abduction, extension, and external rotation moments. In F-EX, greater knee abduction angles were found in Cluster 2 and 3 compared to Cluster 1 (p = 0.007). Cluster 2 showed the lowest knee and hip flexion angles (p < 0.013). Cluster 3 showed the greatest hip external rotation angles (p = 0.006). In F-GAME, Cluster 3 presented the greatest knee external rotation and lowest knee flexion angles (p = 0.003). Clinically relevant differences towards ACL injury identified in the laboratory reflected at-risk patterns only in part when cutting on the field: in the field, low-risk players exhibited similar kinematic patterns as the high-risk players. Therefore, in-lab injury risk screening may lack ecological validity. [ABSTRACT FROM AUTHOR]

To determine polyethylene deformation in well-functioning meniscal bearing PCL-retaining total knee prosthesis a quantitative stereophotogrammetric analysis was carried out over 5 years’ follow-up. Polyethylene plastic deformation was obtained by tracking the intermarker distance variations of five tantalum beads inserted into the polyethylene prior to surgery in a known position. Plastic deformation occurred in the posteromedial part of the meniscal bearing. Radiostereometric analysis was a useful tool to monitor the load distribution in vivo on the polyethylene of this meniscal bearing prosthesis. This analysis revealed a very similar pattern of plastic deformation in the polyethylene insert of this prosthesis design to the wear pattern revealed with different methodologies in PCL-retaining fixed-bearing prosthesis. [ABSTRACT FROM AUTHOR]

Abstract: We assessed 30 patients with a cemented TKR implant (Interax ISA®, Stryker Orthopaedics) at 1 and 3 years follow-up. We wanted to ascertain whether knee alignment was maintained during the critical period of follow-up in meniscal-bearing PCL-retaining TKR patients and test if correlations exist between alignment variations in the coronal plane and preoperative varus/valgus deformity or tibial component position and migration with respect to the tibia. Lower limb alignment was evaluated by measuring the angle between the tibia and femur anatomical axis directly from the antero-posterior radiographs and the tibial component position with respect to the tibial anatomical axis. The tibial component varus/valgus migration in the tibia was measured by roentgen stereophotogrammetric analysis. The results showed that at 3 years follow-up 40% of patients presented an alignment variation of over 3°. The recurrent deformity was not correlated with the preoperative deformity, nor with the tibial component position with respect to the tibial shaft nor with its migration. After total knee arthroplasty coronal axial variation is a common finding and it depends on the overall limb muscles and ligaments adaptation to prosthetic constraints. [Copyright &y& Elsevier]

Introduction: The aim of the study was to investigate the kinematics of the distal tibiofibular syndesmosis in intact and ligament injured ankles and to assess how effective is the syndesmotic screw in restraining mortise width variations during passive foot flexion. Materials and methods: The trials were carried out on seven fresh frozen cadaver specimens. The distal tibiofibular syndesmosis widening was investigated using Roentgen stereophotogrammetric analysis, in intact and ligament injured ankles and after the fixation of the syndesmotic screw. The AO-ASIF recommendations were followed for screw implant. Results: Injury to the syndesmotic and deltoid ligaments of the ankle did not result in a significant variation of the syndesmosis behavior during passive foot flexion. The 4.5-mm diameter cortical screw used in this study proved effective in restraining mortise width variation during foot flexion. The recorded mortise widening in the flexion arc extending from the neutral to the maximally dorsiflexed position was negligible in intact and ligament injured joints. Conclusion: The result does not endorse the recommendation of placing the foot in full dorsal flexion during screw implantation. The choice of screw fixation as a treatment for ankle syndesmosis disruption should be carefully evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Roentgen Stereophotogrammetric Analysis (RSA) is the most accurate technique to measure micromotion between rigid bodies and it has been widely used in the orthopedic field to investigate lower limb prostheses. The aim of this paper was to investigate the factors affecting the accuracy of measurements performed on the knee joint by the biplanar RSA system. Errors were assessed by means of a test object. A particular goal was to verify the reliability of the system when the patient cannot stand in the ideal position during the examination, i.e. in the centre of the calibration space. Results showed that detection of micromotion is not correlated to the position of markers inside the calibration space. The influence of different materials able to simulate human tissues, both hard and soft, on the data acquisition phase was also investigated. This additional exam was performed to assess whether the results obtained were similar also under as close as possible conditions to the clinical trials. Different experimental conditions were shown to not affect the acquisition phase of RSA procedure; markers were acquired with equal accuracy independently of tissues examined. Since the acquisition procedure is often performed by different operators, the difference between acquisitions made by different operators was compared. This study confirms the reliability of RSA and its accuracy, also in non-standard clinical setup and acquisition procedures. [Copyright &y& Elsevier]

Abstract: Roentgen stereophotogrammetric analysis (RSA) under stress conditions was used to investigate possible stress-inducible displacement of the tibial component of unicompartmental knee prostheses (UKR) in which the stability was previously assessed by radiographic evaluation and standard supine RSA examinations. Sixteen patients, implanted with Duracon UNI® prosthesis, were selected for this study. The RSA protocol included examinations in plain upright standing posture and during execution of stress-inducing tasks in weight-bearing stance. The first follow-up was performed at an average of 14 months, and the second one at 26 months. The results showed non-negligible stress-induced rotations of the prosthetic tibial component in all the patients in most of the stress tasks performed. Rotational stress tasks and squatting turned out to be the stress conditions in which induced displacement reached the most significant values (p&#60;0.05). These micromotions occurred mainly around the transverse axis of the knee joint and in one examination around the sagittal axis. Stress-induced translations were negligible in all the examinations. Moreover, we focused our attention on two patients suffering from inexplicable pain, and we observed a significant difference in the inducible rotation around the x-axis between these patients and the remaining fourteen. Stress-inducible displacement is a common finding in knee prostheses, but we observed that in patients with inexplicable pain, these micromotions reached values greater than the median calculated on patients without any pain. This result suggests the introduction of the stress-inducible displacement as a new parameter to be taken into consideration when analyzing the outcome of patients treated by UKR. [Copyright &y& Elsevier]

Purpose: To explore in vivo kinematical behavior of the same total knee arthroplasty (TKA) cruciate-retaining (CR) femoral design with either medial-congruent (MC) or ultra-congruent (UC) inlay using model-based dynamic radiostereometric analysis (RSA). The hypothesis was that there would be comparable kinematics between the two groups. Methods: A cohort of 16 randomly selected patients (8 MC Persona Zimmer, 8 UC Persona Zimmer) was evaluated through dynamic radiostereometric analysis (RSA) at a minimum of 9 months after TKA, during the execution of a sit-to-stand. The antero-posterior (AP) translation of the femoral component and the AP translation of the low point of medial and lateral femoral compartments were compared through Student's t test (p < 0.05). Results: Both groups showed a medial pivot behavior, with a significantly greater anterior translation of the Low Point of the lateral compartment with respect to the medial compartment (MC medial range: 2.4 ± 2.4 mm; MC lateral range: 7.7 ± 3.0 mm; p < 0.001 – UC medial range: 3.3 ± 3.3 mm; UC lateral range: 8.0 ± 3.2 mm; p < 0.001). A statistically significant greater degree of flexion was clinically recorded at follow-up visit in the MC group respect to the UC group (126° vs 101°—p = 0.003). Conclusion: The present study did not show difference in the medial pivot behavior between ultra-congruent and medial-congruent total knee arthroplasty when implanted with mechanical alignment; however, the MC group demonstrated a greater degree of flexion. The MC design examined is a valid alternative to the UC design, allowing to achieve a screw-home movement restoration combined with a high flexion. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Individual performance in team sports is a multifactorial reflection of how well a player can cope and accomplish tasks in varied playing situations. Thus, performance analysis should not only focus on outcomes, but also on underlying mechanisms of those outcomes. We adopted principles of the ecological dynamics approach (EDA) to investigate the effect of introducing constraints on players' joint coordination responses for a football-specific performance drill outcome. Seventeen talented youth football (soccer) players performed a football-specific drill under different conditions: basic constraints, additional defender dummies, stroboscopic glasses, and a combination of the latter two constraints. We recorded these players' execution time, passing accuracy, and lower extremity joint kinematics. We calculated joint coordination for hip-knee, knee-ankle, and trunk-hip couplings. The added constraints negatively affected execution time and passing accuracy, and caused changes in joint coordination. Furthermore, we identified a relationship between execution time and joint coordination. This study serves as an example how the EDA can be adopted to investigate mechanisms that underlie individual performance in team sports. [ABSTRACT FROM AUTHOR]

Abstract Purpose Methods Results Conclusion \nIMPLICATIONS FOR REHABILITATION Exoskeleton can assist individuals with spinal cord injuries (SCI) with simple movements and transform their lives by enhancing strength and mobility. Nonetheless, the current utilization outside of rehabilitation contexts is limited. To promote the widespread adoption of exoskeletons, it is crucial to consider the acceptance of these devices for both rehabilitation and functional purposes. This systematic review aims to identify the barriers or facilitators of the use of lower limbs exoskeletons, thereby providing strategies to improve interventions and increase the adoption of these devices.A comprehensive search was conducted in EMBASE, Web of Science, Scopus, Cochrane, and PubMed. Studies reporting barriers and facilitators of exoskeleton use were included. The studies’ quality was assessed using the Mixed Methods Appraisal Tool and undertook a thematic content analysis for papers examining the barriers and facilitators.Fifteen articles met the inclusion criteria. These revealed various factors that impact the utilization of exoskeletons. Factors like age, engagement in an active lifestyle, and motivation were identified as facilitators, while fear of falling and unfulfilled expectations were recognized as barriers. Physical aspects such as fatigue, neuropathic discomfort, and specific health conditions were found to be barriers.This systematic review provides a comprehensive overview of the barriers and facilitators to the use of exoskeleton technology. There are therefore still challenges to be faced, efforts must be made to improve its design, functionality, and accessibility. By addressing these barriers, exoskeletons can significantly improve the quality of life of people with SCI. Optimize the use of this technology to adapt as much as possible to individual needs. Offer an in-depth understanding of the challenges that can arise when adopting exoskeletons. Highlight the critical issues with the device, that prevent me from using it outside of clinical contexts. Offer useful information to therapists to select the most suitable patients for the use of the exoskeleton and to customize rehabilitation programs more effectively. Optimize the use of this technology to adapt as much as possible to individual needs.Offer an in-depth understanding of the challenges that can arise when adopting exoskeletons.Highlight the critical issues with the device, that prevent me from using it outside of clinical contexts.Offer useful information to therapists to select the most suitable patients for the use of the exoskeleton and to customize rehabilitation programs more effectively. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the in vivo kinematics of the same femoral design mechanically aligned posterior-stabilised (PS) total knee arthroplasty (TKA) with either fixed-bearing (FB) or mobile-bearing (MB) inlay, implanted by the same surgeon, using model-based dynamic radiostereometric analysis (RSA). The hypothesis of the present study was that the MB design would show wider axial rotation than the FB design, without affecting the clinical outcomes. Materials and methods: A cohort of 21 non-randomised patients (21 DePuy Attune PS-FB) was evaluated by dynamic RSA analysis at a minimum 9-month follow-up, while performing differently demanding daily living activities such as sit to stand (STS) and deep knee lunge (DKL). Kinematic data were compared with those of a cohort of 22 patients implanted with the same prosthetic design but with MB inlay. Anterior–posterior (AP) translations, varus–valgus (VV) and internal–external (IE) rotations of the femoral component with respect to the tibial baseplate were investigated. Translation of medial and lateral compartment was analysed using the low point method according to Freeman et al. Questionnaires to calculate objective and subjective clinical scores were administered preoperatively and during follow-up visit by the same investigator. Results: The FB TKA design showed lower AP translation during STS (6.8 ± 3.3 mm in FB vs 9.9 ± 3.7 mm in MB, p = 0.006*), lower VV rotation (1.9 ± 0.8° in FB vs 5.3 ± 3.3° in MB, p = 0.005) and lower IE rotation (2.8 ± 1.1° in FB vs 9.5 ± 4.3° in MB, p = 0.001) during DKL than the mobile-bearing TKA design. Posterior-stabilised FB group showed significant lower translation of the low point of the medial compartment than the MB group (p = 0.008). The percentage of patients performing medial pivot in the FB group was higher compared to MB group in the examined motor tasks. No significant differences in post-operative range of motion (117° ± 16° for FB group and 124° ± 13° for MB group) and in clinical outcomes emerged between the two cohort. Conclusions: The FB and MB designs differed in AP translations, VV rotations and IE rotations of the femoral component with respect to the tibial component in STS and DKL. Furthermore, FB cohort reported a significant higher percentage of medial pivot with respect to MB cohort. Despite this, no differences in clinical outcomes were detected between groups. Both designs showed stable kinematics and represent a viable option in primary TKA. Level of evidence: Prospective cohort study, II. [ABSTRACT FROM AUTHOR]

The aim of the present case report was to provide a longitudinal functional assessment of a patient with transfemoral amputation from the preoperative status with socket-type prosthesis to one year after the osseointegration surgery. A 44 years-old male patient was scheduled for osseointegration surgery 17 years after transfemoral amputation. Gait analysis was performed through 15 wearable inertial sensors (MTw Awinda, Xsens) before surgery (patient wearing his standard socket-type prosthesis) and at 3-, 6-, and 12-month follow-ups after osseointegration. ANOVA in Statistical Parametric Mapping was used to assess the changes in amputee and sound limb hip and pelvis kinematics. The gait symmetry index progressively improved from the pre-op with socket-type (1.14) to the last follow-up (1.04). Step width after osseointegration surgery was half of the pre-op. Hip flexion-extension range significantly improved at follow-ups while frontal and transverse plane rotations decreased (p < 0.001). Pelvis anteversion, obliquity, and rotation also decreased over time (p < 0.001). Spatiotemporal and gait kinematics improved after osseointegration surgery. One year after surgery, symmetry indices were close to non-pathological gait and gait compensation was sensibly decreased. From a functional point of view, osseointegration surgery could be a valid solution in patients with transfemoral amputation facing issues with traditional socket-type prosthesis. [ABSTRACT FROM AUTHOR]

Pivoting sports expose athletes to a high risk of knee injuries, mainly due to mechanical overloading of the joint which shatters overall tissue integrity. The present study explored the magnitude of tibiofemoral contact forces (TFCF) in high-risk dynamic tasks. A novel musculoskeletal model with modifiable frontal plane knee alignment was developed to estimate the total, medial, and lateral TFCF developed during vigorous activities. Thirty-one competitive soccer players performing deceleration and 90° sidestepping tasks were assessed via 3D motion analysis by using a marker-based optoelectronic system and TFCF were assessed via OpenSim software. Statistical parametric mapping was used to investigate the effect of frontal plane alignment, compartment laterality, and varus–valgus genu on TFCF. Further, in consideration of specific risk factors, sex influence was also assessed. A strong correlation (R = 0.71 ÷ 0.98, p < 0.001) was found between modification of compartmental forces and changes in frontal plane alignment. Medial and lateral TFCF were similar throughout most of the tasks with the exception of the initial phase, where the lateral compartment had to withstand to higher loadings (1.5 ÷ 3 BW higher, p = 0.010). Significant sex differences emerged in the late phase of the deceleration task. A comprehensive view of factors influencing the mediolateral distribution of TFCF would benefit knee injury prevention and rehabilitation in sport activities. [ABSTRACT FROM AUTHOR]

Diving saves are the main duty of football goalkeepers. Few biomechanical investigations of dive techniques have been conducted, none in a sport-specific environment. The present study investigated the characteristics of goalkeepers' dive in preferred (PS) and non-preferred (nPS) side through an innovative wearables-plus-principal-component analysis (PCA) approach. Nineteen competitive academy goalkeepers (16.5 ± 3.0 years) performed a series of high and low dives on their PS and nPS. Dives were performed in a regular football goal on the pitch. Full-body kinematics were collected through 17 wearable inertial sensors (MTw Awinda, Xsens). PCA was conducted to reduce data dimensionality (input matrix 310,878 datapoints). PCA scores were extracted for each kinematic variable and compared between PS and nPS if their explained variability was >5%. In high dive, participants exhibited greater hip internal rotation and less trunk lateral tilt (p < 0.047, ES > 0.39) in PS than nPS. In low dives, players exhibited greater ipsilateral hip abduction dominance and lower trunk rotation (p < 0.037, ES > 0.40) in PS than nPS. When diving on their nPS, goalkeepers adopted sub-optimal patterns with less trunk coordination and limited explosiveness. An ecological testing through wearables and PCA might help coaches to inspect relevant diving characteristics and improve training effectiveness. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to compare the in vivo under weight-bearing kinematic behavior of a posterior-stabilized (PS) and an ultra-congruent (UC) total knee arthroplasty (TKA) model during a sit-to-stand motor task, a common activity of daily life. Methods: A cohort of 16 randomly selected patients (8 PS Persona Zimmer, 8 UC Persona Zimmer) was evaluated through dynamic radiostereometric analysis (RSA) at a minimum of 9 months after TKA, during the execution of a sit-to-stand. The anteroposterior (AP) translation of the femoral component and the AP translation of the low point of medial and lateral femoral compartments were compared through Student's t test (p < 0.05). Results: A significantly greater anterior translation of the femoral component was found for the PS group compared to the UC group. The flexion interval where statistical significance was found was between 30° and 0° (p = 0.017). Both groups showed a significantly greater anterior translation of the low point of the lateral compartment with respect to the medial one (PS: p = 0.012, UC: p = 0.018). This was consistent with a medial-pivot pattern. Furthermore, a significantly greater anterior translation of the medial compartment was found in the PS group compared to the UC group (p = 0.001). The same pattern was observed for the lateral compartment (p = 0.006). Conclusions: The TKA designs evaluated in the present study showed comparable in-vivo kinematics with regards to medial pivot pattern but differences in absolute AP translation. Specifically, the UC design showed greater AP stability than the PS design. This finding could be positive in terms of implant stability, but negative in terms of premature polyethylene wear and thus implant failure. This remains to be verified in studies with a larger sample size and longer follow-up. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: To investigate if postoperative clinical outcomes correlate with specific kinematic patterns after total knee arthroplasty (TKA) surgery. The hypothesis was that the group of patients with higher clinical outcomes would have shown postoperative medial pivot kinematics, while the group of patients with lower clinical outcomes would have not. Methods: 52 patients undergoing TKA surgery were prospectively evaluated at least a year of follow-up (13.5 ± 6.8 months) through clinical and functional Knee Society Score (KSS), and kinematically through dynamic radiostereometric analysis (RSA) during a sit-to-stand motor task. Patients received posterior-stabilized TKA design. Based on the result of the KSS, patients were divided into two groups: "KSS > 70 group", patients with a good-to-excellent score (93.1 ± 6.8 points, n = 44); "KSS < 70 group", patients with a fair-to-poor score (53.3 ± 18.3 points, n = 8). The anteroposterior (AP) low point (lowest femorotibial contact points) translation of medial and lateral femoral compartments was compared through Student's t test (p < 0.05). Results: Low point AP translation of the medial compartment was significantly lower (p < 0.05) than the lateral one in both the KSS > 70 (6.1 mm ± 4.4 mm vs 10.7 mm ± 4.6 mm) and the KSS < 70 groups (2.7 mm ± 3.5 mm vs 11.0 mm ± 5.6 mm). Furthermore, the AP translation of the lateral femoral compartment was not significantly different (p > 0.05) between the two groups, while the AP translation of the medial femoral compartment was significantly higher for the KSS > 70 group (p = 0.0442). Conclusion: In the group of patients with a postoperative KSS < 70, the medial compartment translation was almost one-fourth of the lateral one. Surgeons should be aware that an over-constrained kinematic of the medial compartment might lead to lower clinical outcomes. Level of evidence: II. [ABSTRACT FROM AUTHOR]

Background: The World Health Organization stated an average of 60 min of Moderate to Vigorous Physical Activity (MVPA) that children should accumulate every day. Nevertheless physical inactivity is growing and, due to restrictions imposed during pandemic, PA levels of children might be more negatively affected. The study aimed to analyse the impact of COVID-19 on the PA of an Italian sample of primary school children by comparing it before and during COVID-19 considering gender differences.Methods: A pre-post analysis (October 2019-January 2021) was conducted using a randomized sample (N = 77) from the I-MOVE study settled in an Italian primary school. Both objective (Actigraph accelerometers) and self-reported (PAQ-c questionnaires) assessments of PA were performed. Changes were compared using T-Student and Chi-Square test. Gender differences were calculated using Anova.Results: Weekly and daily minutes time spent in MVPA significantly decreased respectively by - 30.59 ± 120.87 and - 15.32 ± 16.21 from before to during pandemic while the weekly time spent in sedentary behaviour increased (+ 1196.01 ± 381.49). PAQ-c scores followed the same negative trend (- 0.87 ± 0.72). Boys seem to have suffered more than girls from the imposed restrictions.Conclusion: These findings outline the need for strategies to promote PA and reduce sedentary behaviours in children to prevent COVID-19 restriction long-term effects. [ABSTRACT FROM AUTHOR]

Purpose: The deceleration (pressing) is a common situational pattern leading to anterior cruciate ligament (ACL) injury in football. Although mainly assessed for performance purposes, a stronger focus on movement quality might support the screening of at-risk athletes. The aim of the present study was to describe a 2D scoring system for the assessment of the deceleration task and to associate it with the knee joint loading (knee abduction moment) evaluated through the gold standard 3D motion capture. The hypothesis was that lower 2D scores would be associated with higher knee joint loading. Methods: Thirty-four competitive football (soccer) players (age 22.8 ± 4.1, 16 females) performed a series of deceleration tasks. 3D motion analysis was recorded using ten stereophotogrammetric cameras, a force platform, and three high-speed cameras. The 2D qualitative assessment was performed via a scoring system based on the video analysis of frontal and lateral planes joint kinematics for five scoring criteria. The intra- and inter-rater reliabilities were calculated for each 2D scoring criteria. The peak knee abduction moment was extracted and grouped according to the results of the 2D evaluation. Results: An ICC > 0.94 was found for all the 2D scoring criteria, both for intra-rater and inter-rater reliability. The players with low 2D frontal plane scores and low total scores (0–4) showed significantly higher peak knee abduction moment values (p < 0.001). A significant negative rank correlation was found between the total score and the peak knee abduction moment (ρ = − 0.25, p < 0.001). Conclusions: The qualitative 2D scoring system described successfully discerned between athletes with high and low knee joint loading during a deceleration task. The application of this qualitative movement assessment based on a detailed and accurate scoring system is suitable to identify players and patients with high knee joint loading (high knee abduction moments) and target additional training in the scenario of the primary and secondary ACL injury risk reduction. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to trace knee position at the time of bone bruise (BB) and investigate how much this position departed from the knee biomechanics of an in vivo flexion–extension. Methods: From an original cohort of 62 patients, seven (11%) presented bicompartmental edemas and were included in the study. 3D models of bones and BB were obtained from MRI. Matching bone edemas, a reconstruction of the knee at the moment of BB was obtained. For the same patients, knee kinematics of a squat was calculated using dynamic Roentgen sterephotogrammetric analysis (RSA). Data describing knee position at the moment of BB were compared to kinematics of the same knee extrapolated from RSA system. Results: Knee positions at the moment of BB was significantly different from the kinematics of the squat. In particular, all the patients' positions were out of squat range for both anterior and proximal tibial translation, varus–valgus rotation (five in valgus and two in varus), tibial internal–external rotation (all but one, five externally and one internally). A direct comparison at same flexion angle between knee at the moment of BB (average 46.1° ± 3.8°) and knee during squat confirmed that tibia in the former was significantly more anterior (p < 0.0001), more externally rotated (6.1 ± 3.7°, p = 0.04), and valgus (4.1 ± 2.4°, p = 0.03). Conclusion: Knee position at the moment of Bone bruise position was out of physiological in-vivo knee range of motion and could reflect a locked anterior subluxation occurring in the late phase of ACL injury rather than the mechanism leading to ligament failure. Level of evidence: Level IV [ABSTRACT FROM AUTHOR]

Abstract: The present work aims to evaluate the mobility of the polyethylene bearing in 25 patients implanted with a mobile-bearing PCL-retaining TKR (Interax ISA, Striker Howmedica) under in vivo, weight-bearing conditions over 3 years'' follow-up. We compared the bearing motion in response to specific tests in two consecutive follow-ups with Roentgen Stereophotogrammetric Analysis (RSA). Results showed that polyethylene continued to displace on the tibial baseplate over time: longitudinal rotations and medio-lateral translations tended to increase at the second follow-up (mean increases 0.7±2.5° and 0.34±1.08 mm, respectively), while sagittal translations did not show any relevant change. Longitudinal rotations and AP translations were preserved when present at both follow-ups. Nevertheless, no statistical evidence of repeatable pattern of motion was found, since bearings frequently reversed their pattern of motion between the two follow-ups. The unconstrained polyethylene mobility resulted in an unrepeatable, erratic pattern of bearing motion intra-patient and over time. The changes in knee motion were found not to affect the clinical results over the first 3 years of follow-up. As in a fixed-bearing design, mobile-bearing design was not able to reproduce normal knee kinematics. [Copyright &y& Elsevier]

Background: Knee stiffness after total knee arthroplasty (TKA) often leads to pain and discomfort, failing to meet patients' expectations on the surgical procedure. Despite the growing debate on the topic, a comprehensive literature analysis of stiffness causes has never been conducted. Thus, the purpose of the present study was to systematically review the literature regarding the main causes of stiffness after TKA. Methods: Pubmed Central, Scopus, and EMBASE databases were systematically reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for studies on stiffness and pain or discomfort after TKA through November 2020. Overall, 25 articles matched the selection criteria and were included in the study. Clinical relevance and strength of evidence of the included studies were graded using the risk of bias and the methodological index for non-randomized studies quality assessment tools. Results: The main causes of pain and discomfort due to stiffness were surgery-related issues, i.e., component malpositioning and over-voluming, implant loosening, psychological distress, and obesity, which could be considered "modifiable" factors, and expression of profibrotic markers, high material hypersensitivity-related cytokines level, male gender, previous contralateral TKA, and high pre-operative pain, which could be considered "non-modifiable" factors. Conclusion: The use of alternative technologies such as surgical robots, anatomy-based devices, and more inert and less stiff component materials could help in reducing stiffness caused by both modifiable and even some non-modifiable factors. Furthermore, early diagnostic detection of stiffness onset could consistently support surgeons in patient-specific decision-making. [ABSTRACT FROM AUTHOR]

Periods of absence from supervised group exercise while maintaining physical activity might be a frequent pattern in adults' exercise habits. The aim of the present study was to determine detraining effects on musculoskeletal outcomes after a 3-month detraining period in early post-menopausal, osteopenic women. Due to the COVID-19 pandemic, we terminated the 18-month randomized controlled ACTLIFE exercise intervention immediately after the 13-month follow-up assessment. This put an abrupt stop to the high-intensity aerobic and resistance group exercise sessions undertaken three times per week by the exercise group (EG: n = 27) and the gentle exercise program performed once per week for the attention control group (CG: n = 27); but both groups were permitted to conduct individual outdoor activity for the 3-month lock-down period. Study endpoints were lean body mass (LBM), bone mineral density (BMD) at the lumbar spine (LS), maximum hip-/leg extension strength and power. Detraining-induced reductions of LBM, hip/leg strength and power (but not BMD-LS) were significantly greater (p < 0.001 to p = 0.044) compared with the CG. Significant exercise effects, i.e. differences between EG and CG, present after 13 months of exercise, were lost after 3 months of detraining for LBM (p = 0.157) and BMD-LS (p = 0.065), but not for strength (p < 0.001) and power (p < 0.001). Of note, self-reported individual outdoor activities and exercise increased by about 40% in both groups during the lock-down period. Three months' absence from a supervised group exercise protocol resulted in considerable detraining effects for musculoskeletal parameters. Thus, exercise programs for adults should be continuous rather than intermittent. Trial registration number: ClinicalTrials.gov: NCT04420806, 06.05.2020. [ABSTRACT FROM AUTHOR]

Purpose: The role of the anterior cruciate ligament (ACL) in knee biomechanics in vivo and under weight-bearing is still unclear. The purpose of this study was to compare the tibiofemoral kinematics of ACL-deficient knees to healthy contralateral ones during the execution of weight-bearing activities. Methods: Eight patients with isolated ACL injury and healthy contralateral knees were included in the study. Patients were asked to perform a single step forward and a single leg squat first with the injured knee and then with the contralateral one. Knee motion was determined using a validated model-based tracking process that matched subject-specific MRI bone models to dynamic biplane radiographic images, under the principles of Roentgen stereophotogrammetric analysis (RSA). Data processing was performed in a specific software developed in Matlab. Results: Statistically significant differences (p < 0.05) were found for single leg squat along the frontal plane: ACL-deficient knees showed a more varus angle, especially at the highest knee flexion angles (40°–50° on average), compared to the contralateral knees. Furthermore, ACL-deficient knees showed tibial medialization along the entire task, while contralateral knees were always laterally aligned. This difference became statistically relevant (p < 0.05) for knee flexion angles included between 0° and about 30°. Conclusion: ACL-deficient knees showed an abnormal tibial medialization and increased varus angle during single leg squat when compared to the contralateral knees. These biomechanical anomalies could cause a different force distribution on tibial plateau, explaining the higher risk of early osteoarthritis in ACL deficiency. The clinical relevance of this study is that also safe activities used in ACL rehabilitation protocols are significantly altered in ACL deficiency. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate if there was a correlation between in vivo kinematics of a medial-stabilized (MS) total knee arthroplasty (TKA) and post-operative clinical scores. We hypothesized that (1) a MS-TKA would produce a medial pivot movement and that (2) this specific pattern would be correlated with higher clinical scores.Methods: 18 patients were evaluated through clinical and functional scores evaluation (Knee Society Score clinical and functional, Womac, Oxford), and kinematically through dynamic radiostereometric analysis (RSA) at 9 months after MS-TKA, during the execution of a sit-to-stand and a lunge motor task. The anteroposterior (AP) Low Point translation of medial and lateral femoral compartments was compared through Student's t test (p < 0.05). A correlation analysis between scores and kinematics was performed through the Pearson's correlation coefficient r.Results: A significantly greater (p < 0.0001) anterior translation of the lateral compartment with respect to the medial one was found in both sit-to-stand (medial 2.9 mm ± 0.7 mm, lateral 7.1 mm ± 0.6 mm) and lunge (medial 5.3 mm ± 0.9 mm, lateral 10.9 mm ± 0.7 mm) motor tasks, thus resulting in a medial pivot pattern in about 70% of patients. Significant positive correlation in sit-to-stand was found between the peak of AP translation in the lateral compartment and clinical scores (r = 0.59 for Knee Society Score clinical and r = 0.61 for Oxford). Moreover, we found that the higher peak of AP translation of the medial compartment correlated with lower clinical scores (r = - 0.55 for Knee Society Score clinical, r = - 0.61 for Womac and r = - 0.53 for Oxford) in the lunge. A negative correlation was found between Knee Society Score clinical and VV laxity during sit-to-stand (r = - 0.56) and peak of external rotation in the lunge motor task (r = - 0.66).Conclusions: The MS-TKA investigated produced in vivo a medial pivot movement in about 70% of patients in both examined motor tasks. There was a correlation between the presence of medial pivot and higher post-operative scores.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the present study was to assess the kinematical behavior of a multi-radius posterior-stabilized (PS) mobile-bearing (MB) total knee arthroplasty (TKA) during an activity of daily living (Sit-To-Stand—STS) and a high demanding motor task (Deep-Knee-Lunge—DKL) using model-based dynamic RSA. We hypothesized the achievement of medial pivoting movement in both motor tasks due to the congruent geometry of the inlay with the femoral component, which should allow good stability of the medial compartment, and to the high magnitude of rotations guaranteed by the MB on the tibial side. Methods: Twenty-two randomly selected patients were recruited and prospectively evaluated. The PS MB cemented TKA was implanted with the standard technique (medial parapatellar approach, adjusted mechanical alignment). At minimum 9-month follow-up, patients were examined with model based Dynamic RSA developed in our Institute (BI-STAND DRX 2) during the execution of two motor tasks: STS and DKL. The motion parameters were evaluated using the Grood and Suntay decomposition and the low-point kinematics methods. Results: In the extension phase of DKL femur performed a greater antero posterior translation of 3.8 mm compared to STS between 0° and 20° of knee flexion (p < 0.05). Low-point analysis showed a medial pivoting movement in both motor tasks: in 62% of patients during STS and 48% during DKL. Varus-valgus rotations were lower than 1° during all the range-of-motion in both motor tasks without differences. Conclusions: Medial pivot was partially produced by this multi-radius PS MB TKA with some differences during activity of daily living (STS) and high demanding motor task (DKL). Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: Which total knee arthroplasty (TKA) design represents the better solution to restore a correct knee biomechanics is still debated. The aim of this study was to compare posterior stabilized (PS) and cruciate retaining (CR) version of the same TKA design (femoral component with an anatomic sagittal radius-J-curve design) by the use of dynamic Roentgen stereophotogrammetric analysis (RSA). The hypothesis was that the two models influence differently in vivo knee kinematic.Methods: A cohort of 16 randomly selected patients was evaluated 9 months after surgery: Zimmer PERSONA® was implanted, eight with CR design and eight with PS design. The kinematic evaluations were performed using a Dynamic RSA (BI-STAND DRX 2) developed in our Institute, during the execution of the sit-to-stand motor task. The motion parameters were obtained using the Grood and Suntay decomposition and the low-point kinematics methods.Results: PS TKA lateral femoral compartment had a wider anterior translation (17 ± 2 mm) than the medial one (11 ± 2 mm), while the two compartments of CR TKA showed a similar anterior translation (medial: 9 ± 2 mm/lateral: 11 ± 2 mm). T test for comparison between CR and PS TKA of antero-posterior translation showed a statistically significant difference (p < 0.05) in the flexion range between 15° and 40°. The CR prosthesis did not anteriorly translate during flexion. The PS design translated anteriorly showing a roll-forward mechanism during extension from 80° to 18° of flexion and a posterior translation from 18° to 0°. The same significant differences (p < 0.05) between the PS and CR groups were found comparing the low-point positions of the femoral condyles in the range of flexion between 25° and 40° for the medial compartment and between 15° and 25° for the lateral compartment.Conclusions: Dynamic RSA was able to investigate for the first time in vivo the kinematic behaviour of PS and CR version of the same TKA J-curve design. PS type showed a medial pivot during sit-to-stand motion task, while the CR type showed a cylindrical movement. Further studies are needed to evaluate the impact of different TKA designs on clinical results.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: To determine the medium-term implant survivorship, the clinical results and the failure mechanisms of a novel unicompartmental arthroplasty for uncemented resurfacing of the medial tibio-femoral compartment.Methods: Seventy-six consecutive patients were prospectively evaluated with a mean final follow-up of 6 years (SD 5.3 months). In 44 patients, the diagnosis was osteoarthritis, and in 32 patients, it was avascular necrosis of the medial femoral condyle. The Hospital for Special Surgery Score was used for objective clinical evaluation, and a self-administered visual analogue scale was used to quantify residual pain at each observation point. Implant survivorship was determined assuming revision for any reason as endpoint.Results: Nineteen patients were revised (6 with osteoarthritis and 13 with avascular necrosis of the medial femoral condyle). The mean interval time from index surgery to revision was 11.2 months (SD 4.66 months). Implant survivorship was higher in patients with osteoarthritis with respect to those with avascular necrosis of the medial femoral condyle (p = 0.018). Aseptic loosening was the most frequent failure mechanism. Femoral component loosening was reported in five patients and tibial component loosening was reported in other six patients. Assuming revision for any reason as endpoint, an implant survivorship of 74.3 % at 6-year follow-up was determined. In the remaining 57 patients, satisfactory clinical results were obtained. Hospital for Special Surgery Score and visual analogue scale for residual pain showed significant improvements (p < 0.03 and p < 0.045, respectively).Conclusions: At the present time, the standard cemented implants and the conventional designs for unicompartmental knee replacement still represent the optimal solution. The authors do not recommend the widespread use of this technique.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: To present the results of a survival analysis of a series of 147 arthroscopic MAT procedures.Methods: One-hundred and forty-seven patients (117 males and 30 females) underwent arthroscopic MAT without bone plugs (82 medial MAT and 65 lateral MAT) using fresh-frozen, non-irradiated grafts. They were retrospectively reviewed at a mean of 4.0 ± 1.9-year follow-up. Mean age at surgery was 40.9 ± 11.2 (range 16.7-68.8) years; 70 patients (48 %) underwent combined procedures. Clinical evaluation was performed with KOOS, Lysholm and a 0-100 VAS for pain. Survival analysis was performed using two endpoints: surgical failure (revision procedure with direct relation to MAT) and clinical failure (revision procedure or poor Lysholm score, <65).Results: There was a significant (p < 0.05) and clinically relevant decrease in the VAS and increase in KOOS and Lysholm from pre-operative mean score to post-operative mean score. Seven (5 %) patients (two medial and five lateral) experienced surgical failure (five meniscectomies, one lateral graft peripheral suture and one unicompartmental knee arthroplasty). The mean overall survival time was 9.7 years (CI 9.1-10.3). As 16 (11 %) patients presented poor Lysholm score, a total of 23 (16 %) patients were considered clinical failures. The mean overall survival time was 8 years (CI 7.1-8.8). No statistically significant differences in failure and survival rate were present between medial and lateral MAT, isolated or combined MAT, patients >50 or <50 years old and patients with body mass index <25 or >25.Conclusions: MAT, eventually associated with other needed procedures, was able to significantly relieve pain and improve function of the knee joint at midterm follow-up, with a survival rate from 9.7 to 8.0 years based on failure criteria. Most additional procedures were done in the first 2 post-operative years. MAT eventually associated with other needed procedures could represent an effective treatment for post-meniscectomy syndrome.Level Of Evidence: Therapeutic study, retrospective case series, Level IV. [ABSTRACT FROM AUTHOR]

Purposes: To determine the long-term survival rate of an all-polyethylene tibial unicompartmental knee arthroplasty (UKA) in a large series of consecutive patients and to investigate the possible factors that could influence the outcome.Methods: A retrospective evaluation of 273 patients at 6-13 years of follow-up was performed. Clinical evaluation was based on KSS and WOMAC scores. Subjective evaluation was based on a visual analogue scale for pain self-assessment. Radiographic evaluation was performed to assess femoral-tibial angle (FTA), posterior tibial slope (PTS) and tibial plateau angle (TPA). A Kaplan-Meier survival analysis was performed assuming revision for any reason as primary endpoint.Results: The 10-year implant survivorship was 87.6%. Twenty-five revisions (9.2%) were performed, and aseptic loosening of the tibial component was the most common failure mode (11 cases, 4%). The comparison of survival rate according to age at surgery did not show significant difference. Age at surgery, FTA, TPA and PTS were not related to higher risk of revision. No correlations were found between BMI, age at surgery and clinical scores. Finally, no statistical differences of radiographic measurements were found between revisions and non-revisions.Conclusions: The present study has demonstrated on a large series of patients that UKA with an all-polyethylene tibial component, with an accurate technique and a proper patient selection, can provide a satisfactory clinical and functional outcome and a good overall survivorship of the implant at long-term follow-up. These advantages could be achieved at a lower cost.Level Of Evidence: Retrospective Therapeutic Study, Level IV. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to perform a mid-long-term clinical and radiographic evaluation of the results obtained in patients older than 75 years treated with minimally invasive unicompartmental knee arthroplasty (UKA). The hypothesis was that UKA is a viable solution for the definitive treatment of localized disease in this age group, with good results and a low failure rate.Methods: An all-poly tibial component UKA was applied with a minimally invasive technique. Sixty-seven knees in patients with a minimum age of 75 years were evaluated at mean 9 years' follow-up. The Oxford knee score, Knee Society Score, WOMAC score, Visual Analogue Scale (VAS) for pain self-assessment and range of motion (ROM) were determined, as well as weight-bearing antero-posterior and laterolateral radiographs.Results: All clinical scores, as well as VAS and ROM, improved significantly at 9-year follow-up, and the outcome was considered good or excellent in 92.6% of the patients. Radiographic results showed that both tibial plateau angle and posterior tibial slope angles were maintained, whereas femoro-tibial angle was significantly changed at follow-up. Further analysis showed no significant correlation between clinical scores and body mass index, whereas the clinical outcome was correlated with the ROM obtained. Only two failures and one major post-operative complication were observed.Conclusions: UKA is a viable option for treating unicompartmental knee osteoarthritis. With the proper indications and an accurate technique UKA may be indicated also in very elderly patients with reduced complications and morbidity, and excellent survivorship. [ABSTRACT FROM AUTHOR]

Purpose: "Early Osteoarthritis (EOA)" has been defined combining clinical, imaging and surgical parameters, with the aim to identify patients in early degenerative phases, who might benefit from the use of available regenerative procedures. Aim of this first clinical trial is to prospectively evaluate the results obtained in a group of patients meeting the inclusion criteria of "EOA" as proposed by the ESSKA Cartilage Committee, and surgically treated with the implantation of a multi-phasic osteochondral scaffold.Methods: 23 patients were prospectively evaluated at 12 and 24 months of follow-up. Etiology of the chondral or osteochondral defect was rated as microtraumatic or degenerative in 18 cases, and traumatic in 5 cases. Patients included were complaining of clinical symptoms like knee pain and affected by chondral and osteochondral lesions located at the femoral condyles or trochlea and MRI findings demonstrating articular cartilage degeneration and/or meniscal degeneration and/or subchondral bone marrow lesions.Results: All patients increased significantly in any clinical score adopted. The IKDC subjective score increased from 42.8 ± 13.8 at basal evaluation to 74.3 ± 17.4 at 12 months' (p < 0.0005), being stable (74.9 ± 20.4) up to the final follow-up of 24 months. Tegner score showed a statistically significant improvement in sports activity from 3.3 ± 2.7 pre-operative to 4.6 ± 2.2 at 12 months (p < 0.005), with a slight improvement to the final evaluation (4.7 ± 2.1; n.s.). However, the activity level was significantly lower than the pre-injury one (6.1 ± 2.6; p = 0.004). A significant difference was shown between patients younger versus older than 40 years, with younger patients had better clinical improvement (76.0 ± 18.6 vs 45.1 ± 38.8 respectively, p = 0.037).Conclusions: The implantation of a multi-phasic osteochondral scaffold represents a good option after failure of conservative management for Early OA patients, where younger age represent an important factor for a better outcome. Longer follow-up is needed to evaluate the benefit over time.Level Of Evidence: IV, case series. [ABSTRACT FROM AUTHOR]

• The greater material stiffness reduction could be achieved implementing internal body gaps with hexagonal or circular transversal section. • A stiffness reduction up to 12% has been achieved in Young Modulus in cube with prismatic gaps realized through circular transversal section. • Internal gaps distributed in 4 mm of thickness could be quite enough to obtain stiffness reduction. In orthopedic medical devices, elasto-plastic behavior differences between bone and metallic materials could lead to mechanical issues at the bone-implant interface, as stress shielding. Those issue are mainly related to knee and hip arthroplasty, and they could be responsible for implant failure. To reduce mismatching-related adverse events between bone and prosthesis mechanical properties, modifying the implant's internal geometry varying the bulk stiffness and density could be the right approach. Therefore, this feasibility study aims to assess which in-body gap geometry improves, by reducing, the bulk stiffness. Using five finite element models, a uniaxial compression test in five cubes with a 20 mm thickness was simulated and analyzed. The displacements, strain and Young Modulus were calculated in four cubes, each containing internal prismatic gaps with different transversal sections (squared, hexagonal, octagonal, and circular). Those were compared with a fifth full-volume cube used as control. The most significant difference have been achieved in displacement values, in cubes containing internal gaps with hexagonal and circular transversal sections (82 µm and 82.5 µm, respectively), when compared to the full-volume cube (69.3 µm). This study suggests that hexagonal and circular shape of the gaps allows obtaining the lower rigidity in a size range of 4 mm, offering a starting approach to achieve a "close-to-bone" material, with a potential use in prosthetic devices with limited thickness. [ABSTRACT FROM AUTHOR]

The article reviews the Anatomical theatre of the Archiginnasio, which designed by Antonio Levanti in the University of Bologna in Bologna, Italy, and mentions the linden-wood statues which are present on the walls of the theatre.

Purpose: A general agreement on the best surgical treatment option of chronic proximal patellar tendinopathy is still lacking. The purpose of this systematic review was to investigate if arthroscopically assisted procedures have been reported better results compared to open surgery and to assess the methodology of studies. Methods: Twenty-one studies were included in the review. Surgical outcomes were defined referring to the functional classification described by Kelly et al. (Am J Sports Med 12(5):375-380, []): return to sport was regarded as the ability of training at the original level before injury with mild or moderate pain and success as the improvement after surgery with symptom reduction. Methodological analysis was performed by two reviewers adopting the Coleman Methodology Score (CMS) (range 0-100, best score 100). Results: Only one randomized controlled trial (RCT) met inclusion criteria; all other included studies were case series. Median sample size 24, range 11-138, mean age at surgery 26.8 ± 3.2 years, mean follow-up 32.5 ± 18.4 (median 31, range 6-60) months. Return to sport rate: global 78.5 %, open group 76.6 % and arthroscopic group 84.2 %. Success rate: global 84.6 %, open group 87.2 % and arthroscopic group 92.4 %. Differences between groups were not statistically significant. CMSs were positively correlated with the year of publication ( P < 0.05). Conclusions: Minimally invasive arthroscopically assisted procedures have not reported better statistically significant results when compared to open surgery in the treatment of chronic proximal patellar tendinopathy. The methodology of studies in this field has improved over the past 15 years, but well-designed RCTs using validated patient-based outcome measures are still lacking. Level of evidence: Systematic Review, Level IV. [ABSTRACT FROM AUTHOR]

Purpose: Degenerative cartilage lesions present a negative joint environment, which may have a negative effect on the process of cartilage regeneration. The aim of this study is to analyze the clinical outcome obtained with the treatment for isolated degenerative knee cartilage lesions by second-generation arthroscopic autologous chondrocyte implantation (ACI). Methods: Fifty-eight consecutive patients affected by focal degenerative chondral lesions of the femoral condyles and trochlea were treated by second-generation arthroscopic ACI. The mean age at surgery was 34.7 ± 9.1 years and the average defect size was 2.3 ± 0.9 cm. The patients were prospectively evaluated with IKDC, EQ-VAS, and Tegner scores preoperatively, at 2 and 6 years. Results: A statistically significant improvement was observed in all scores from the basal evaluation to the final follow-up. The IKDC subjective score improved from 39.3 ± 13.6 to 68.8 ± 22.7 and 68.5 ± 23.9 at the 2- and 6-year follow-ups, respectively, with a significant improvement ( P < 0.0005) and stable results over time; the same trend was confirmed by the EQ-VAS and Tegner scores. The worst results were found in patients with a low physical activity level, women, and those having undergone previous surgery, whereas the symptom duration before surgery did not influence the final outcome. The failure rate was 18.5%. Conclusions: Despite a significant improvement, the results were lower with respect to the outcome reported in different study populations, and the number of failures was markedly higher, too. Tissue-engineered cartilage implantation is a promising approach for the treatment of degenerative chondral lesions, but graft properties, besides mechanical and biochemical joint environment, have to be improved. Level of evidence: Case series, Level IV. [ABSTRACT FROM AUTHOR]

We performed a retrospective clinical and radiographic evaluation of 83 nonconsecutive patients operated in our institute between February 1996 and March 2003 with a mean follow-up of 60 months to assess the efficiency of unicompartmental knee replacement (UKR) performed with a minimally invasive technique. The aim of this study was to correlate the clinical outcome with the pre- and post-operative alignment and with implant positioning on coronal and sagittal plane. Eighty-three nonconsecutive patients (60 males, 23 females) underwent cemented UKR (De Puy Preservation Uni with all-poly tibial component), for both medial OA (80 patients) and AVN of the medial femoral condyle (3 patients). All patients were available at final follow-up evaluation, and they all presented an evident varus alignment at pre-operative clinical and radiographic evaluation. At radiographic measurement, we considered a knee with femoro-tibial angle (FTA) > 175° as varus knee, 170° < FTA < 175° as normal knee and a knee with a FTA < 170° as a valgus knee. Moreover, we considered a tibial plateau angle (TPA) > 90° for valgus knee and a TPA < 90° for varus knee. According to Hospital for Special Surgery (HSS) scoring system, at a mean follow-up of 60 months, 61 (74%) cases were excellent (100-85 points), 15 (18%) cases were good (84-70 points) and 7 cases (8%) had fair results (<70 points). In our series, patients with an excellent clinical result presented a mean varus deformity of 7.2° (3.6°–10.8°) pre-operatively. According to literature, we demonstrated that a small amount of undercorrection with a small amount of residual varus deformity of 3°–5° is the goal to be reached in order to avoid both rapid degeneration of the nonreplaced compartment and the premature loosening of the replaced compartment. We performed a mean axial correction of 5° (SD 3.9°), leaving a mean axial varus deformity of 2.2° in the excellent group. In our series, the group with excellent results also showed a post-operative PTS of 7° (2.4°–11.6°), while mean pre-operative PTS was 6.5° (2.7°–10.3°). In this study, results have shown that minimally invasive UKR producing a small amount of varus undercorrection in selected patients with medial tibio-femoral osteoarthritis or moderate avascular necrosis of the medial femoral condyle provides excellent clinical and functional results. Overcorrection of varus malalignment with a UKR may produce both rapid degeneration of the lateral tibio-femoral compartment and the early failure of the replaced compartment. [ABSTRACT FROM AUTHOR]

The process of bone loss occurs silently and progressively with age, often appearing as osteopenia or osteoporosis or related fractures. Given the rapid raise in disease burden and socio-economic costs of these conditions worldwide, drug therapy combined with physical activity can be a useful strategy and bone biomarkers, can represent a useful evaluation tool to assess their effects. The objective of this systematic review, conducted according to PRISMA statement, was to investigate the effects of physical activity interventions combined with drug treatments on bone biomarkers in people with osteopenia and osteoporosis. Through PubMed, Cochrane, Cinahl, Embase, Trip, a comprehensive literature search was performed. Each study's quality was assessed according to the Cochrane risk-of-bias tool. Out of 582 identified articles, 50 full texts were screened. Only one matched the eligibility criteria. The study, scored as high quality, showed, in both experimental and control groups, an increase of CTX and P1NP bone biomarkers, without statistically significant differences. Based on available evidence, no exhaustive conclusion can be drawn. However, this systematic review critically analyses the literature, highlighting the knowledge gap on combined treatments efficacy assessed by bone biomarkers. Moreover, an outlook is provided for the planning of future studies. [ABSTRACT FROM AUTHOR]

Motor coordination and lower limb biomechanics are crucial aspects of anterior cruciate ligament (ACL) injury prevention strategies in football. These two aspects have never been assessed together in real scenarios in the young population. The present study aimed to investigate the influence of motor coordination on lower limb biomechanics in young footballers during an on-the-pitch training. Eighteen juvenile football players (10 y ± 2 m) were enrolled. Each player performed a training drill with sport-specific movements (vertical jump, agility ladders, change of direction) and the Harre circuit test (HCT) to evaluate players' motor coordination. Wearable inertial sensors (MTw Awinda, Xsens) were used to assess lower limb joint angles and accelerations. Based on the results of the HCT, players were divided into poorly coordinated (PC) and well-coordinated (WC) on the basis of the literature benchmark. The PC group showed a stiffer hip biomechanics strategy (up to 40% lower flexion angle, ES = 2.0) and higher internal-external hip rotation and knee valgus (p < 0.05). Significant biomechanical limb asymmetries were found only in the PC group for the knee joint (31–39% difference between dominant and non-dominant limb, ES 1.6–2.3). Poor motor coordination elicited altered hip and knee biomechanics during sport-specific dynamic movements. The monitoring of motor coordination and on-field biomechanics might enhance the targeted trainings for ACL injury prevention. [ABSTRACT FROM AUTHOR]

• Femur and tooth were the most investigated bone segments. • A bonded bone-implant interface was used in about half of the studies. • 3D simulations were predominantly used. • The bone remodeling function proposed by Huiskes et al. (1987) was used in more than half of the retrieved studies. • The change in bone density was the most investigated outcome. The aim of the present study was to review the literature concerning the analysis of periprosthetic bone remodeling through finite element (FE) simulation. A systematic review was conducted on 9 databases, taking into account a ten-year time period (from 2009 until 2020). The inclusion criteria were: articles published in English, publication date after 2009, full text articles, articles containing the keywords both in the abstract and in the title. The articles were classified through the following parameters: dimensionality of the simulation, modelling of the bone-prosthesis interface, output parameters, type of simulated prosthesis, bone remodeling algorithm. Sixty-seven articles were included in the study. Femur and tooth were the most evaluated bone segment (respectively 41.8% and 29.9%). The 55.2% of the evaluated articles used a bonded bone-prosthesis interface, 73% used 3D simulations, 67.2% of the articles (45 articles) evaluate the bone remodeling by the bone density variation. At last, 59.7% of the articles employed algorithms based on a specific remodeling function. Increasing interest in the bone remodeling FE analysis in different bone segments emerged from the review, and heterogeneous solutions were adopted. An optimal balance between computational cost and accuracy is needed to accurately simulate the bone remodeling phenomenon in the post-operative period. [ABSTRACT FROM AUTHOR]

The aim of the present study was to quantify joint kinematics through a wearable sensor system in multidirectional high-speed complex movements used in a protocol for rehabilitation and return to sport assessment after Anterior Cruciate Ligament (ACL) injury, and to validate it against a gold standard optoelectronic marker-based system. Thirty-four healthy athletes were evaluated through a full-body wearable sensor (MTw Awinda, Xsens) and a marker-based optoelectronic (Vicon Nexus, Vicon) system during the execution of three tasks: drop jump, forward sprint, and 90° change of direction. Clinically relevant joint angles of lower limbs and trunk were compared through Pearson's correlation coefficient (r), and the Coefficient of Multiple Correlation (CMC). An excellent agreement (r > 0.94, CMC > 0.96) was found for knee and hip sagittal plane kinematics in all the movements. A fair-to-excellent agreement was found for frontal (r 0.55–0.96, CMC 0.63–0.96) and transverse (r 0.45–0.84, CMC 0.59–0.90) plane kinematics. Movement complexity slightly affected the agreement between the systems. The system based on wearable sensors showed fair-to-excellent concurrent validity in the evaluation of the specific joint parameters commonly used in rehabilitation and return to sport assessment after ACL injury for complex movements. The ACL professionals could benefit from full-body wearable technology in the on-field rehabilitation of athletes. [ABSTRACT FROM AUTHOR]