Lateral Tilt Research Articles

Repositioning mattress: how a lateral tilt position reshapes the prevention of pressure ulcers in bedridden patients

Pressure ulcers have been part of tissue damage without effectiveness in medical, surgical, and intensive care units. This study aims to focus on developing lateral tilt positions for effective pressure ulcer relief for bedridden patients. A repositioning mattress was placed in the side-lying left lateral tilt position (15°, 30°, 45°), sheering (0.680, 1.323, 1.870), interface pressure (2.550, 2.290, 2.830), and placed at 1.5 m long piece of polyethylene rubber. The design strength was set at 6000 N and 2100 mm x 1105 mm ( = 42, = 34). The design shows the greatest supine position at 30°, 1.323, 2.290, pressure load ( = 1.125 (1820) 2050 psi, = 1.125 (620) 700 psi), tensile stress ( (MPa) = 42), compressive stress ( (MPa) = 34), and FOS ( = 42, = 34). The factor of safety illustrated that the 30° lateral tilt position is more consistent in repositioning for pressure ulcer prevention compared to the supine-to-tilt region. Further, an application of repositioning mattresses was developed to test in bedridden patients with tissue ulcers in nursing homes.

Automatic measurement of the patellofemoral joint parameters in the Laurin view: a deep learning-based approach.

To explore the performance of a deep learning-based algorithm for automatic patellofemoral joint (PFJ) parameter measurements from the Laurin view. A total of 1431 consecutive Laurin views of the PFJ were retrospectively collected and divided into two parts: (1) the model development dataset (dataset 1, n = 1230) and (2) the hold-out test set (dataset 2, n = 201). Dataset 1 was used to develop the U-shaped fully convolutional network (U-Net) model to segment the landmarks of the PFJ. Based on the predicted landmarks, the PFJ parameters were calculated, including the sulcus angle (SA), congruence angle (CA), patellofemoral ratio (PFR), and lateral patellar tilt (LPT). Dataset 2 was used to assess the model performance. The mean of three radiologists who independently measured the PFJ parameters was defined as the reference standard. Model performance was assessed by the intraclass correlation coefficient (ICC), mean absolute difference (MAD), and root mean square (RMS) compared to the reference standard. Ninety-five percent limits of agreement (95% LoA) were calculated pairwise for each radiologist, reference standard, and model. Compared with the reference standard, U-Net showed good performance for predicting SA, CA, PFR, and LPT, with ICC = 0.85-0.97, MAD = 0.06-5.09, and RMS = 0.09-6.90 in the hold-out test set. Except for the PFR, the remaining parameters measured between the reference standard and the model were within the 95% LoA in the hold-out test dataset. The U-Net-based deep learning approach had a relatively high model performance in automatically measuring SA, CA, PFR, and LPT. • The U-Net model could be used to segment the landmarks of the PFJ and calculate the SA, CA, PFR, and LPT, which could be used to evaluate the patellar instability. • In the hold-out test, the automatic measurement model yielded comparable performance with reference standard. • The automatic measurement model could still accurately predict SA, CA, PFR, and LPT in patients with PI and/or PFOA.

Paper 35: High School and Professional Pitchers with Early Excessive Ipsilateral Trunk Tilt: A Newly Characterized Parameter for Biomechanical Evaluation

Objectives:Though contralateral trunk tilt has been frequently studied in baseball pitchers, the phenomena of excessive ipsilateral trunk tilt has not been explored as a potential correlate with throwing arm kinetics. Excessive ipsilateral trunk tilt is often observed during earlier portions of the pitch cycle. High school pitchers with excessive contralateral trunk tilt during the late cocking phase of pitching have been noted to have significantly faster ball velocity, as well as increased elbow distraction force, shoulder distraction force, elbow varus torque, and shoulder internal rotation torque. Collegiate pitchers with excessive contralateral trunk tilt at maximum shoulder external rotation and at ball release have significantly faster ball velocity and higher elbow varus torque. The purpose of this study was to evaluate the effect of ipsilateral and contralateral trunk tilt on kinetic and kinematic parameters among high school and professional baseball pitchers.Methods:Professional and high school baseball pitchers were assessed with 3D-motion capture technology (480 Hz) while pitching in a controlled laboratory setting. Pitchers were grouped into ipsilateral, neutral, or contralateral trunk tilt groups based on the degree of lateral trunk tilt at foot contact (FC) and ball release (BR) (Figure 1). Trunk and shoulder kinematics, as well as throwing arm kinetics, were compared between subgroups with post-hoc regression analysis.Results:Professional pitchers (n=287) had significantly higher ipsilateral trunk tilt at FC (p<0.001) compared to high school pitchers (n=59) (Figure 2). High school pitchers with excessive contralateral trunk tilt at BR experienced significantly higher shoulder superior force (27.0 ± 7.4 vs. 17.6 ± 5.1 %Body Weight [BW] respectively, p<0.001) and shoulder anterior force (39.6 ± 8.2 vs. 35.7 ± 5.4 %BW respectively, p<0.001) compared to the ipsilateral trunk tilt cohort, while accomplishing comparable ball velocity (30.2±3.2 vs. 30.4±2.1m/s, p=0.633). For professional pitchers, for every 10° increase in ipsilateral trunk tilt at FC, ball velocity increased by 0.2 m/s (B: 0.02, β: 0.07, SE: 0.005, p=0.010), while elbow varus torque (EVT) decreased by 0.1%BWxHeight (B: -0.01, β: -0.08, SE: 0.002, p<0.001) and shoulder internal rotation torque (SIRT) decreased by 0.1 %BWxHeight (B: -0.01, β: -0.07, SE: 0.002, p=0.005).Conclusions:High school and professional pitchers with excessive ipsilateral trunk tilt at FC consistently demonstrated significantly decreased throwing arm kinetics (high school: shoulder anterior force, shoulder superior force; professional: SIRT, EVT) compared to pitchers with excessive contralateral trunk tilt at BR, with at least equivalent ball velocity. In addition, professional pitchers already appear to engage in significantly greater ipsilateral trunk tilt at early portions of the pitch cycle when compared to high school pitchers, which may represent a kinetically favorable method adopted by pitchers at higher playing levels to maintain adequate ball velocity while concomitantly minimizing throwing arm kinetics. While contralateral trunk tilt has previously been associated with throwing arm kinetics in high school and collegiate pitchers, ipsilateral lateral trunk tilt has not been assessed in professional pitchers, a subgroup characterized by distinct pitching kinematics compared to amateur pitchers. Further research is warranted to determine if the kinetic impact of trunk tilt during the throwing motion of baseball pitchers impacts the risk of injury.UPLOAD-https://planion-client-files.s3.amazonaws.com/AOSSM/blobs/ada6d538-50e8-460e-ac42-c385825f1ce4/1/Trunk_Tilt_Fig_2.docx Figure 1.Lateral trunk till in pitchers; (+) indicates ipsilaleral trunk till, (-) indicates contralateral trunk tilt.

Changes in Anatomic Risk Factors for Patellar Instability During Skeletal Growth and Maturation

Background: Several anatomic risk factors have been identified in the pathogenesis of patellofemoral instability. The literature is sparce regarding how these anatomic risk factors change during skeletal growth and development. Hypothesis: The anatomic risk factors associated with patellar instability change significantly during skeletal growth and maturation with different patterns in male versus female patients. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Magnetic resonance imaging data from 240 unique, asymptomatic knees (7-18 years of age; 50% female) were used to measure patellar height (Caton-Deschamps index), lateral patellar tilt angle, trochlear height, trochlear groove depth, trochlear sulcus angle, and tibial tubercle–trochlear groove (TT-TG) distance. Linear regression was used to test the associations between age and anatomic findings. Two-way analysis of variance with Holm-Šídák post hoc test was used to compare anatomic characteristics between sexes in 3 age groups: prepubertal school-aged children (7-10 years old), early adolescents (11-14 years old), and late adolescents (15-18 years old). Results: Patellar height (female sex), lateral patellar tilt angle (male sex), and trochlear sulcus angle (both sexes) decreased with age (P < .001). Trochlear height, depth, and TT-TG distance increased with age in both male and female participants (P < .02). Male participants had a larger sulcus angle (by 5.3°± 1.6° at age 11-14 years) and greater trochlear height (by >5 mm across medial, central, and lateral regions at age 15-18 years) than age-matched female participants (P < .01). We found no other sex-related differences in quantified anatomic features (P > .1). Conclusion: The findings partially support our hypothesis indicating significant age-related changes in all quantified features, which were not different between male and female participants except for trochlear sulcus angle in early adolescence and trochlear height in late adolescence. In general, the majority of anatomic risk factors for patellar instability change with maturity in a direction that assists in reducing the risk of patellar instability and/or dislocation. The only outlier is the TT-TG distance, which increased by age, and in our oldest cohort of patients, the mean fell below the normal adult range. The current observations highlight the importance of age in the interpretation of risk for injury as well as the need for further studies to identify intrinsic and extrinsic factors that may result in abnormal development of these anatomic features during skeletal growth and maturation.

Kinetic Evaluation of Pelvis during the Three Trimesters of Pregnancy and its Correlation to BMI

Background: Understanding differences in mechanics between pregnant and non-pregnant females are a first step toward identifying potential pathological mechanisms. Objectives: The objective was to investigate systematic changes in the range of motion of pelvis in all three trimesters of pregnancy and its correlation to BMI. Materials and Methods: One hundred and seventy-four primigravida pregnant females with age group of 20–30 years completed testing on three occasions (first trimester, second trimester, and third trimester) using goniometer. The patient was made comfortable and her height, weight was measured to calculate the BMI. Later with the help of goniometer range of motion of pelvis (hip and lumbar) was measured. Results: In this study, significant correlation was seen for anterior pelvic tilt, posterior pelvic tilt, and backward rotation for the first and third trimester. Very significant correlation was seen for anterior pelvic tilt, posterior pelvic tilt, lateral pelvic tilt, forward rotation, backward rotation in the second trimester, and for backward rotation in the third trimester. Extremely significant correlation was seen for posterior pelvic tilt in the first trimester, for anterior and posterior pelvic tilt in the second trimester, for posterior pelvic tilt in the third trimester. Conclusion: In this study, significant correlation was seen for the first and third trimester. Very significant correlation was seen for the second trimester and for third trimester. Extremely significant correlation was seen in the first trimester, second trimester, and third trimesters.

The effect of planning time on penultimate and ultimate step kinematics and subsequent knee moments during sidestepping.

Frontal plane postures during the ultimate step of sidestepping are linked to increased anterior cruciate ligament injury risk. However, there is a lack of research detailing the kinematic strategies present in the penultimate step. This study, therefore, investigated penultimate and ultimate step kinematics of planned sidestepping (pSS) and unplanned sidestepping (upSS) to further understand the effect of planning time on known ultimate step kinematic and kinetic differences. Sixty male amateur Australian Rules football players performed three trials of straight-line running (RUN), pSS, and upSS in a randomized order. Mediolateral foot placement and three-dimensional joint kinematics for the knee, pelvis, and trunk were measured at final foot contact of the penultimate step and initial foot contact of the ultimate step. Peak knee moments were measured during the weight acceptance phase of the ultimate step. In pSS, at the penultimate step final foot contact, the support foot was placed across the midline of the center of mass, in the frontal plane, contralateral to the sidestep direction. Greater trunk lateral flexion toward the sidestep direction and greater negative pelvic lateral tilt were observed in pSS compared with upSS and RUN. Differences between pSS and upSS frontal plane kinematics at penultimate step final foot contact suggest preparatory reorientation strategies are likely constrained by the amount of planning time available. As there are clear differences in preparatory kinematics, we recommend that planning time be considered when training and assessing sidestepping maneuvers and planned and unplanned maneuvers not be treated as interchangeable skills.

Effect of Different Positions During Surgical Preparation With Combined Spinal-Epidural Anesthesia for Elective Cesarean Delivery: A Randomized Controlled Trial

(Anesth Analg. 2021;133:1235–1243) A lateral tilt of the uterus is used to reduce pressure on the inferior vena cava in pregnant patients undergoing cesarean delivery. This may improve the fetal blood and oxygen supply. This position has been thought to improve the fetal acid-base status, though this has been recently called into question. This study aimed to evaluate whether moving the patient into a 30 degrees left lateral tilt position before elective cesarean delivery with combined spinal-epidural anesthesia could better improve the fetal acid-base status compared with a 15 degrees left lateral tilt or supine position.

Concurrent validity and reliability of a semi-automated approach to measuring the magnetic resonance imaging morphology of the knee joint in active youth.

Post-traumatic knee osteoarthritis is attributed to alterations in joint morphology, alignment, and biomechanics triggered by injury. While magnetic resonance (MR) imaging-based measures of joint morphology and alignment are relevant to understanding osteoarthritis risk, time consuming manual data extraction and measurement limit the number of outcomes that can be considered and deter widespread use. This paper describes the development and evaluation of a semi-automated software for measuring tibiofemoral and patellofemoral joint architecture using MR images from youth with and without a previous sport-related knee injury. After prompting users to identify and select key anatomical landmarks, the software can calculate 37 (14 tibiofemoral, 23 patellofemoral) relevant geometric features (morphology and alignment) based on established methods. To assess validity and reliability, 11 common geometric features were calculated from the knee MR images (proton density and proton density fat saturation sequences; 1.5 T) of 76 individuals with a 3-10-year history of youth sport-related knee injury and 76 uninjured controls. Spearman's or Pearson's correlation coefficients (95% CI) and Bland-Altman plots were used to assess the concurrent validity of the semi-automated software (novice rater) versus expert manual measurements, while intra-class correlation coefficients (ICC2,1; 95%CI), standard error of measurement (95%CI), 95% minimal detectable change, and Bland-Altman plots were used to assess the inter-rater reliability of the semi-automated software (novice vs resident radiologist rater). Correlation coefficients ranged between 0.89 (0.84, 0.92; Lateral Trochlear Inclination) and 0.97 (0.96, 0.98; Patellar Tilt Angle). ICC estimates ranged between 0.79 (0.63, 0.88; Lateral Patellar Tilt Angle) and 0.98 (0.95, 0.99; Bisect Offset). Bland-Altman plots did not reveal systematic bias. These measurement properties estimates are equal, if not better than previously reported methods suggesting that this novel semi-automated software is an accurate, reliable, and efficient alternative method for measuring large numbers of geometric features of the tibiofemoral and patellofemoral joints from MR studies.

Changes in Patellofemoral Joint Morphology During Skeletal Growth and Maturation are not Sex-Dependent

Background:Patellofemoral disorders account for approximately 25% of patients seen in sports medicine clinics. A variety of anatomic risk factors have been identified in the pathogenesis of patellofemoral instability. While studies have analyzed these factors in adults, or compared them between healthy controls and patients with patellar injuries, little is known about how these anatomic markers change during skeletal growth and development.Hypothesis/Purpose:(A) The anatomic risk factors associated with patellar instability and dislocation change significantly during skeletal maturation. (B) These age-related changes during maturation will differ between male and female patients.Methods:After institutional review board approval, magnetic resonance imaging data from 239 unique knees (patient age 7-18; 55% female), without previous or current injury, were randomly selected and used to measure patellar height, lateral patellar tilt angle, trochlear width, trochlear depth, trochlear sulcus angle, and tibial tubercle trochlear groove distance. Linear regression was used to test the associations between age and anatomic measurement indices. Subsequently, patients were divided into four age groups: pre-pubertal school-aged children (7-10 years old), early adolescents (11-14 years old), and late adolescents (15-18 years old). Additionally, two-way analysis of variance with the Holm-Sidak post hoc test was used to compare anatomic morphologies between male and female patients in each age group.Results:Patellar height (Caton-Deschamps index), lateral patellar tilt angle and trochlear sulcus angle all decreased significantly with age (P<0.001). Trochlear width, depth, and tibial tubercule trochlear groove distance all increased significantly with age (P<0.001). Except for trochlear width in late adolescence (P<0.001) where males had wider trochlea (medial and lateral) compared to matched females, the age-related anatomic changes were similar between males and females (P>0.1).Conclusion:The findings partially support our hypothesis, as we observed significant age-related changes in all quantified anatomical indices, which was not different (except trochlear width in late adolescence) between males and females. The lack of significant differences in key morphological features of the patellofemoral joint that are linked to patellar dislocation between females and males is consistent with a similar prevalence of this injury between the two. However, the findings suggest that there are significant differences in the trochlear width between females and males at later stages of growth and maturation. The current observations suggest that these anatomic risk factors undergo significant changes during skeletal growth, providing us with a window of opportunity to use prophylactic interventions to prevent or minimize the development of high-risk morphology.Figure 1.1.CDI: Caton-Deschamps Index; TD: Trochlear Depth; TSA: Trochlear Sulcus Angle; LPTA: Lateral Patellar Tilt Angle TTTG: Tibial Tubercle Trochlear Groove Distance.Figure 1.2.Age- and sex-dependent changes in patellofemoral joint morphology during skeletal growth and maturation. Data are presented as mean and SEM (* P<0.05).

Patellar Tracking in Total Knee Arthroplasty-Influence on Clinical and Functional Outcome.

Anterior knee pain is a common problem after primary total knee arthroplasty (TKA). The aim of this study was to find parameters in patellar positioning which influence the clinical and functional outcome after TKA. Included were 59 patients who underwent TKA, of which three patients were treated bilaterally (n = 62 included knees). In a periodical follow-up of up to 5 years, each patient had to answer three questionnaires (HSS, WOMAC, SF-36) and underwent three radiographies of the knee (including merchant view) and a clinical examination, including Range Of Motion (ROM). All radiographs were evaluated by a single observer blinded to clinical data, who collected multiple parameters of sagittal and axial patellar alignment including newly developed methods for measuring patellar shift and tilt. Depending on the measurement results, three groups were built for each parameter and the influence on the outcome was determined. A lateral patellar tilt of more than 4° resulted in lower scores for both the HSS and WOMAC. The rarely investigated patellar facet angle showed a significantly inferior clinical and functional outcome in late follow-up of >24 months if lower than 142°, possibly due to progressive osteosclerotic changes of the patella caused by increased contact stress with corresponding patellar morphology. No significant difference was found for all other parameters. The newly developed method for measuring patellar shift has proven to be a valuable and easy instrument in the postoperative setting.

Impact of maternal lateral tilt on cardiac output during caesarean section under spinal anaesthesia: a prospective observational study

BackgroundLeft uterine displacement (LUD) has been questioned as an effective strategy to prevent aortocaval compression after spinal anesthesia (SA) for cesarean delivery (CD). We tested if LUD has a significant impact on cardiac output (CO) in patients undergoing CD under SA during continuous non-invasive hemodynamic monitoring with Clearsight.MethodsForty-six patients were included in the final analysis. We considered 4 timepoints of 5 min each: T1 = baseline with LUD; T2 = baseline without LUD; T3 = after SA with LUD; T4 = after SA without LUD. LUD was then repositioned for CD. The primary outcome was to assess if CO decreased from T3 to T4 of at least 1.0 L/min. We also compared CO between T1 and T2 and other hemodynamic variables: mean, systolic and diastolic blood pressure (respectively MAP, SAP and DAP), heart rate (HR), stroke volume (SV), stroke volume variation (SVV), pulse pressure variation (PPV), contractility (dP/dt), dynamic arterial elastance (Eadyn) at the different timepoints. Data on fetal Apgar scores and umbilical arterial and venous pH were collected.ResultsCO did not vary from T3 to T4 (CO mean difference -0.02 L/min [95% CI -0.88 to 0.82; P = 1). No significant variation was registered for any variable at any timepoint.ConclusionsLUD did not show a significant impact on CO during continuous hemodynamic monitoring after SA for CD.Trial registration(retrospectively registered on 03/12/2021) NCT05143684.

Sensation of Anteroposterior and Lateral Body Tilt Induced by Electrical Stimulation of Ankle Tendons

While virtual reality technology enables users to walk on surfaces of various shapes in virtual environments, these experiences are often on a flat floor, and any discordance between visual and somatosensory information hampers the immersive experience. To resolve this issue, we have focused on the ankle joint angle as an essential cue in detecting the surface shape of the ground. To modulate the sensation of the ankle joint angle, we propose novel percutaneous electrical stimulation methods that stimulate four targeted ankle tendons: the tibialis anterior muscle tendon, the Achilles tendon, the peroneus longus muscle tendon, and the flexor digitorum longus tendon. Since electrically stimulating the elbow tendon is known to evoke reflexive hand movement, electrically stimulating the ankle tendon is expected to evoke a body tilt due to illusory changes in the ankle joint angle. In this study, we designed electrode configurations to stimulate the above four ankle tendons using a finite element analysis and investigated the effect of electrically stimulating the ankle tendons on the subjective sensation of body tilt and actual body sway through psychophysical experiments. The results revealed that applying this stimulation with our novel electrode configurations can induce a subjective sensation of body tilt and actual body sway in a direction opposite to the stimulated part.

Manual Leftward Displacement of the Uterus in the Prevention of Maternal Hypotension During Cesarean Section: A Randomized Comparative Study

Background: It is essential to maintain the hemodynamic state of mothers during delivery in cesarean section (CS). Research has shown that hypotension can be controlled by applying a 15° left lateral tilt. This can be achieved using an obstetric wedge or by tilting the operating table leftward. A systematic review of further research shows insufficient evidence to suggest whether it is effective or practical. Objectives: This study aims to evaluate the effectiveness of manual left tilting of the uterus on maintaining the hemodynamic status of mothers undergoing a CS delivery, where a spinal anesthetic has been given. Methods: Seventy women who were candidates for CS deliveries were randomly assigned into 2 groups as follows: group 1, the anaesthesiologist manually maneuvered the mother’s uterus to the left shortly after spinal anesthesia; group 2, the mothers’ uteruses were not displaced to the left. Sixty-seven of 70 participants completed the study. The hemodynamic status of the mother was reported before, during, and after surgery. The total doses of inotropic-vasopressors used to maintain hemodynamic stability were recorded. Results: The mother’s age, vital signs, and body mass index (BMI) before pregnancy and near term were not significantly different. Mothers maintained a significantly higher systolic blood pressure (SBP) when the uterus was displaced to the left (group 1). The mothers also required less ephedrine. Mothers in group 2 suffered a greater decrease in their SBP both after induction and before incision of the abdomen (group 2, P &lt; 0.05). Conclusions: The manual tilting of the uterus to the left during CS is effective in maintaining blood pressure and decreases the need for vasopressors.

The influence of tone on proximal femoral and acetabular geometry in neuromuscular hip displacement: A comparison of cerebral palsy and spinal muscular atrophy.

Purpose:The aim of this article was to compare longitudinal changes in hip morphology in cerebral palsy (hypertonic) and spinal muscular atrophy (hypotonic) to examine the influence of muscle tone on development of hip displacement.Methods:Children with spinal muscular atrophy (Types I and II) and cerebral palsy (Gross Motor Function Classification System IV and V) with hip displacement (migration percentage >30%) were included. Head shaft angle, migration percentage, and acetabular index were measured at T1 (1–2.5 years), T2 (3–5 years), and T3 (6–8 years). Analysis of variance testing and linear regression were utilized.Results:Sixty patients (cerebral palsy, N = 41; spinal muscular atrophy, N = 19) were included. Hip displacement occurred earlier in spinal muscular atrophy (34 months) than cerebral palsy (49 months) (p = 0.003). Head shaft angle was high and did not change between T1, T2, and T3, but significant changes in migration percentage were found (cerebral palsy: 23%, 36%, 45% (p < 0.01) and spinal muscular atrophy: 37%, 57%, 61% (p = 0.02)). Migration percentage increased by age in cerebral palsy (r = 0.41, p < 0.001), but not in spinal muscular atrophy (r = 0.18, p = 0.09). Acetabular index increased with migration percentage (cerebral palsy: r = 0.41, p < 0.001; spinal muscular atrophy: r = 0.48, p < 0.001).Conclusion:Persistent lateral physeal tilt by head shaft angle was found for both spinal muscular atrophy and cerebral palsy. Abnormal physeal alignment may be causally related to weakness of the hip abductor muscles rather than spasticity or muscle imbalance, resulting in coxa valga and secondary acetabular dysplasia.Level of evidence:III (case–control study).

Biomechanical lower limb model to predict patellar position alteration after medial open wedge high tibial osteotomy

Medial open-wedge high tibial osteotomy is a surgical treatment for patients with a varus deformity and early-stage medial knee osteoarthritis. Observations suggest that this surgery can negatively affect the patellofemoral joint and change the patellofemoral kinematics. However, what causes these effects and how the correction angle can change the surgery’s impact on the patellofemoral joint has not been investigated before. The objective of this study was to develop a biomechanical model that can predict the surgery’s impact on the patellar position and find the correlation between the opening angles and the patellar position after the surgery. A combined finite element and multibody model of the lower limb was developed. The model’s capabilities for predicting the patellofemoral kinematics were evaluated by performing a passive deep flexion simulation of the native knee and comparing the outcomes with magnetic resonance images of the study subject at various flexion angles. The model at a fixed knee flexion angle was then used to simulate the high tibial osteotomy surgery virtually. The results showed a correlation between the wedge opening angles and the patellar position in various degrees of freedom. These results indicate that larger wedge openings result in increased values of patellar distalization, lateral patellar shift, patellar rotation, and patellar internal tilt. The developed model in this study can be used in future studies to monitor the stress distribution on the patellar cartilage and connecting tissues to investigate their relationship with observations of pain and cartilage injury due to post-operative altered patellar kinematics.

Effect of shoe insole on the dynamics of lower extremities in individuals with leg length discrepancy during walking

IntroductionThe aim of the present study was to investigate the effect of Internal and External Heel Lift Insoles (IHLI, EHLI) on pelvic kinematics and lower extremity joint moments in subject with mild leg length discrepancy (LLD) during the Stance Phase of walking. MethodsFrom twenty-eight men with mild LLD, kinematic and kinetic data were collected while they walked under each of three conditions (IHLI, EHLI and shoe). Data were collected for both limbs using a six-camera system synchronized with a force platform. For comparisons the dependent variables among the conditions, repeated measures ANCOVA and Bonferroni's post hoc test were used (P ≤ 0.05). ResultsFor both IHLI and EHLI, there were significant decreases in peak long leg lateral and anterior pelvic tilt, long leg hip and knee abduction moments, and short leg ankle plantar flexor moment (P ≤ 0.001). Furthermore, significant increases in peak lateral and anterior pelvic tilt of the short leg were observed in the IHLI and EHLI conditions as compared to the shoe (SH) condition (p ≤ 0.01). In addition, a significant difference was observed between the IHLI and EHLI conditions in the peak values of anterior pelvic tilt of the long leg (p = 0.043) and ankle plantar flexor moment of the short leg (p = 0.044). ConclusionFindings suggest that the use of IHLI and EHLI may be effective in improving pelvic movements (lateral and anterior tilt) and gait dynamics in individuals with LLD. The EHLI could reduce more the peak plantar flexor moment of the short leg and peak anterior pelvic tilt of the long leg than IHLI during stance phase of walking.

How Tilting the Head Interferes With Eye-Hand Coordination: The Role of Gravity in Visuo-Proprioceptive, Cross-Modal Sensory Transformations.

To correctly position the hand with respect to the spatial location and orientation of an object to be reached/grasped, visual information about the target and proprioceptive information from the hand must be compared. Since visual and proprioceptive sensory modalities are inherently encoded in a retinal and musculo-skeletal reference frame, respectively, this comparison requires cross-modal sensory transformations. Previous studies have shown that lateral tilts of the head interfere with the visuo-proprioceptive transformations. It is unclear, however, whether this phenomenon is related to the neck flexion or to the head-gravity misalignment. To answer to this question, we performed three virtual reality experiments in which we compared a grasping-like movement with lateral neck flexions executed in an upright seated position and while lying supine. In the main experiment, the task requires cross-modal transformations, because the target information is visually acquired, and the hand is sensed through proprioception only. In the other two control experiments, the task is unimodal, because both target and hand are sensed through one, and the same, sensory channel (vision and proprioception, respectively), and, hence, cross-modal processing is unnecessary. The results show that lateral neck flexions have considerably different effects in the seated and supine posture, but only for the cross-modal task. More precisely, the subjects’ response variability and the importance associated to the visual encoding of the information significantly increased when supine. We show that these findings are consistent with the idea that head-gravity misalignment interferes with the visuo-proprioceptive cross-modal processing. Indeed, the principle of statistical optimality in multisensory integration predicts the observed results if the noise associated to the visuo-proprioceptive transformations is assumed to be affected by gravitational signals, and not by neck proprioceptive signals per se. This finding is also consistent with the observation of otolithic projections in the posterior parietal cortex, which is involved in the visuo-proprioceptive processing. Altogether these findings represent a clear evidence of the theorized central role of gravity in spatial perception. More precisely, otolithic signals would contribute to reciprocally align the reference frames in which the available sensory information can be encoded.

Multivariate Analysis of Associations between Patellofemoral Instability and Gluteal Muscle Contracture: A Radiological Analysis.

The purpose of this study was to investigate the associations between gluteal muscle contracture (GMC) severity and patellofemoral instability and evaluate the reliability of novel indicators by multivariate analysis. Clinical and imaging data from 115 patients with GMC were collected for retrospective analysis. Two novel indicators were used to evaluate GMC severity (knee flexion angle and hip flexion angle, feet distance), and two additional novel parameters were used to reflect patellofemoral instability [patellar displacement vector (L, α), patella-femoral trochlear (P-FT) area, and femoral-trochlear-patella (FT-P) area]. In this study, patients with moderate contracture were dominant, and 35.65% also experienced anterior knee pain after physical activity. Ordered logistic regression analysis indicated that a more serious GMC represented a higher risk of lateral tilt and lateral displacement of the patella. Multivariate analysis showed that feet distance was a reliable indicator for evaluating the severity of GMC. The results showed that the more serious the GMC, the more significant the difference between the P-FT area and the FT-P area of the patellofemoral joint space. L, patellar tilt angle, patellar congruency angle, and lateral patellofemoral angle were independent risk factors for this difference. A more serious GMC represents a higher risk of patellar subluxation.

Treatment Options for Patellofemoral Arthritis.

To present a synthesis of recent literature regarding the treatment of patellofemoral arthritis RECENT FINDINGS: Risk factors of PFJ OA include patella malalignment or maltracking, injury to supportive structures including the MPFL, dysfunction of hamstring and quadriceps coordination, lower limb alignment, trochlear dysplasia, patellar trauma, or ACL surgery. Special physical exam maneuvers include patellar grind test, apprehension test, and lateral patellar tilt angle. Radiographs that should be obtained first-line include weight bearing bilateral AP, lateral, and Merchant views. CT and MRI are used to assess trochlear dysplasia, excessive patellar height, and TT-TG distance. Non-operative management options discussed include non-pharmacologic treatment (patient education, self-management, physical therapy, weight loss), ESWT, cold therapy, taping, bracing, and orthotics. Pharmacologic management options discussed include NSAIDs, acetaminophen, oral narcotics, and duloxetine. Injection therapies include glucocorticoids, hyaluronic acid, PRP, and other regenerative therapies (BMAC, adipose, or mesenchymal stem cells). Other treatment options include radiofrequency ablation and botulinum toxin. The algorithm for the surgical treatment of PFJ OA can begin with arthroscopic assessment of the PF articular cartilage to address mechanical symptoms and to evaluate/treat lateral soft tissue with or without overhanging lateral osteophytes. If patients fail to have symptomatic improvement, a TTO can be considered in those patients less than 50 years of age or active patients >50 years old. In patients with severe PFJ OA, refractory to the above treatments, PFA should be considered. While early PFA design and technique were less than encouraging, more recent implant design and surgical technique have demonstrated robust results in the literature. Patellofemoral osteoarthritis is a challenging orthopedic problem to treat, in that it can often affect younger patients, with otherwise well-functioning knees. It is a unique entity compared to TF OA with distinct epidemiology, biomechanics and risk factors and treatment options.

Differences in patellofemoral kinematics between weightbearing and non-weightbearing conditions in patients with arthrofibrosis after anterior cruciate ligament reconstruction.

The purpose of this study is to evaluate the difference of patellofemoral kinematics between weightbearing and non-weightbearing conditions in the arthrofibrotic knee after anterior cruciate ligament (ACL) reconstruction. Twenty patients with arthrofibrosis after ACL reconstruction were included in the study. Computed tomography scanner and dual fluoroscopic imaging techniques were used to compare patellofemoral kinematics of the affected knee between weightbearing knee flexion and non-weightbearing knee flexion. In both positions, patellofemoral kinematics in six degrees-of-freedom (6 DOF) were measured respectively. The patellar lateral tilt angle (p = 0.007) and medial patellar translation (p = 0.043) under the weightbearing condition were significantly decreased compared to the non-weightbearing task between 5° and 15° of knee flexion. The lateral patellar translation during a non-weightbearing task was significantly decreased between 60° and 75° of knee flexion (p = 0.005), and the inferior patellar translation under the weightbearing condition was significantly increased between 45° and 75° of knee flexion (p = 0.040). These results indicate that patellofemoral kinematics during non-weightbearing positions do not sufficiently represent the patellar tracking during functional weightbearing activities. Our findings of this study establish the clinical relevance and significance of assessing the patellofemoral kinematics under the weightbearing condition when evaluating patients with arthrofibrosis after ACL reconstruction. Trial registration number: ChiCTR1900025977.