Sagittal Research Articles

Do 3-dimensional Spinopelvic Characteristics Normalize After THA? A Prospective, Comparative Study Using Motion Capture Analysis

Background Spinopelvic stiffness (primarily in the sagittal plane) has been identified as a factor associated with inferior patient-reported outcomes (PROs) and increased dislocation risk after THA. Incorporating preoperative spinopelvic characteristics into surgical planning has been suggested to determine a patient-specific cup orientation that minimizes dislocation risk. Sagittal plane radiographic analysis of static postures indicates that patients exhibit a degree of normalization in their spinopelvic characteristics after THA. It is not yet known whether normalization is also evident during dynamic movement patterns, nor whether it occurs in the coronal and axial planes as well. Questions/purposes (1) Does motion capture analysis of sagittal spinopelvic motion provide evidence of normalization after THA? (2) Do changes in coronal and axial plane motion accompany those in the sagittal plane? Methods Between April 2019 and February 2020, 25 patients agreed to undergo motion capture movement analysis before THA for the treatment of hip osteoarthritis (OA). Of those, 20 underwent the same assessment between 8 and 31 months after THA. Five patients were excluded because of revision surgery (n = 1), contralateral hip OA (n = 1), and technical issues with a force plate during post-THA assessment (n = 3), leaving a cohort total of 15 (median age [IQR] 65 years [10]; seven male and eight female patients). A convenience sample of nine asymptomatic volunteers, who were free of hip and spinal pathology, was also assessed (median age 51 years [34]; four male and five female patients). Although the patients in the control group were younger than those in the patient group, this set a high bar for our threshold of spinopelvic normalization, reducing the possibility of false positive results. Three-dimensional motion capture was performed to measure spinal, pelvic, and hip motion while participants completed three tasks: seated bend and reach, seated trunk rotation, and gait on a level surface. ROM during each task was assessed and compared between pre- and post-THA conditions and between patients and controls. Statistical parametric mapping (SPM) was used to assess the timing of differences in motion during gait, and spatiotemporal gait parameters were also measured. Results After THA, patients demonstrated improvements in sagittal spinal (median [IQR] 32° [18°] versus 41° [14°]; difference of medians 9°; p = 0.004), pelvis (25° [21°] versus 30° [8°]; difference of medians 5°; p = 0.02), and hip ROM (21° [18°] versus 27° [10°]; difference of medians 6°; p = 0.02) during seated bend and reach as well in sagittal hip ROM during gait (30° [11°] versus 44° [7°]; difference of medians 14°; p < 0.001) compared with their pre-THA results, and they showed a high degree of normalization overall. These sagittal plane changes were accompanied by post-THA increases in coronal hip ROM (12° [9°] versus 18° [8°]; difference of medians 6°; p = 0.01) during seated trunk rotation, by both coronal (6° [4°] versus 9° [3°]; difference of medians 3°; p = 0.01) and axial (10° [8°] versus 16° [7°]; difference of medians 6°; p = 0.003) spinal ROM, as well as coronal (8° [3°] versus 13° [4°]; difference of medians 5°; p < 0.001) and axial hip ROM (21° [11°] versus 34° [24°]; difference of medians 13°; p = 0.01) during gait compared with before THA. The SPM analysis showed these improvements occurred during the late swing and early stance phases of gait. Conclusion When restricted preoperatively, spinopelvic characteristics during daily tasks show normalization after THA, concurring with previous radiographic findings in the sagittal plane. Thus, spinopelvic characteristics change dynamically, and incorporating them into surgical planning would require predictive models on post-THA improvements to be of use. Level of Evidence Level II, prognostic study.

Quantifying lumbar sagittal plane kinematics using a wrist-worn inertial measurement unit.

Wearable sensors like inertial measurement units (IMUs), and those available as smartphone or smartwatch applications, are increasingly used to quantify lumbar mobility. Currently, wearable sensors have to be placed on the back to measure lumbar mobility, meaning it cannot be used in unsupervised environments. This study aims to compare lumbar sagittal plane angles quantified from a wrist-worn against that of a lumbar-worn sensor. Twenty healthy participants were recruited. An IMU was placed on the right wrist and the L3 spinal level. Participants had to position their right forearm on their abdomen, parallel to the floor. Three sets of three consecutive repetitions of flexion, and extension were formed. Linear mixed models were performed to quantify the effect of region (lumbar vs. wrist) on six outcomes [minimum, maximum, range of motion (ROM) of flexion and extension]. Only flexion ROM was significantly different between the wrist and lumbar sensors, with a mean of 4.54° (95% CI = 1.82°-7.27°). Across all outcomes, the maximal difference between a wrist-worn and lumbar-worn sensor was <8°. A wrist-worn IMU sensor could be used to measure gross lumbar sagittal plane mobility in place of a lumbar-worn IMU. This may be useful for remote monitoring during rehabilitation.

Radiological and Pulmonary Results of Surgical Treatment of Severe Idiopathic Scoliosis Using Preoperative Halo Gravity Traction Compared with Less Invasive Temporary Internal Distraction in Staged Surgery in Adolescents.

Background: Severe and rigid scoliosis represents a type of spinal deformity characterized by a Cobb angle exceeding 90° and a flexibility of less than 30%. Halo spinal traction remains the established standard for managing severe scoliosis, although alternative approaches such as temporary internal distraction rods and staged surgical correction exist. The primary objective of this investigation was to compare two cohorts of patients treated using these distinct methods to ascertain any divergences in terms of surgical and radiological outcomes, pulmonary function (PF), and quality of life (QoL). Methods: This study encompassed a total of 62 pediatric patients meeting the specified criteria, which included severe idiopathic scoliosis (major Cobb curve >90) and flexibility <30%. Group 1 (G1) underwent surgical intervention involving preoperative Halo gravity traction (HGT) succeeded by posterior spinal fusion (PSF). On the other hand, Group 2 (G2) underwent a two-stage procedure starting with a less invasive temporary internal distraction technique (LITID) prior to PSF. The radiological outcomes, PF, and QoL were documented and assessed over a monitoring period ranging from 2 to 5 years. Results: The average preoperative major curves (MCs) measured 124° and 122° in G1 and G2, respectively (p < 0.426). Initial flexibility, as observed in preoperative bending films, ranged from 18% in G1 to 21% in G2 (p < 0.001). Following the ultimate surgical intervention, the MCs were corrected to 45° and 37.4° in G1 and G2, respectively (p < 0.001). The percentage correction of the MCs was higher in G2 (63% vs. 70% in G1 and G2, respectively), with significant between-group disparities (p < 0.001). The mean preoperative thoracic kyphoses (TKs) were 96.5° in G1 and 92° in G2 (p = 0.782), which were rectified to 45.8° in G1 and 36.2° in G2 (p < 0.001), equating to correction rates of 55% and 60% in the respective groups. Initially, G2 exhibited lower values for the percentage of predicted lung volume (FVC) and predicted FEV1 compared with G1 (49% and 58% vs. 54.5% and 60.8%; N.S.). Nonetheless, both groups demonstrated enhancements in their FVC and FEV1 values over the follow-up period. Conclusions: The surgical management of severe and untreated spinal curvatures in the pediatric and adolescent population can be considered safe, with a tolerable incidence of minor complications. LITID emerges as a method offering improved QoL and pulmonary function, achieving notably substantial average corrections in deformity by 70% in the coronal plane and 60% in the sagittal plane, alongside a mean increase in trunk height of 10.8 cm. Furthermore, a typical reduction of 76% in rib humps and enhancements in respiratory function, as indicated by improvements in 1 s predicted forced expiratory volume (by 25-56%) and forced vital capacity (by 35-65%), were achieved, leading to a clinically and statistically significant enhancement in QoL when evaluated using SRS-22r, without resorting to more radical, high-risk procedures.

Comparative evaluation of two different dental age estimation methods using tooth pulp: A CBCT study.

To estimate the age of an individual based on 3D radiographic evaluation of pulp width of maxillary central incisor. This study included 185 CBCT images of individuals within age range of 14-64 years. Images were evaluated for maxillary central incisors and pulp width measurements were taken from cementoenamel junction and middle third of root. Obtained data was subjected to correlation and regression analysis from which the age of an individual was predicted. Results of the present study were compared with another study by the same authors. A negative linear relationship was obtained between age and pulp width. The standard error of estimate (SEE) in sagittal section was 11.36 years and that in coronal section was 11.23 years. The coefficient of determination for sagittal section was 0.107 and for coronal section was 0.127. An obtained regression formula was highly significant. Division of samples into various age groups reduced SEE drastically. It can be concluded that pulp width of maxillary central incisor is a reliable indicator of age estimation.

Age-related morphological change in bony segment and cartilage segment of Eustachian tube.

Eustachian tube dysfunction (ETD) is the predominant cause of otitis media with effusion in children and adults. Balloon dilatation of the Eustachian tube (BDET) provides a new method for restoring the ventilatory function of Eustachian tube (ET). However, the differences in age-related morphological changes in the dimensions and positions of ET in children and adults are unclear. This study aimed to examine age-related morphological changes in bony and cartilage segments of the ET in a three-dimensional space in normal population. A total of 71 randomly selected computed tomography (CT) images of the temporal bones of 46 people were retrospectively studied in four age groups: A (0-3 years old); B (4-8 years old), C (9-18 years old), and D (19-65 years old). Space analytic geometry was assessed to calculate the dimensions and positions of ET. The bony segment of ET lengthened from infancy to adulthood with age in groups A, B and C (r = 0.562**/0.000). The cartilage segment of ET mostly extended with age from infancy to 8 years old in children (r = 0.633**/0.000), but with bending close to the sagittal plane and away from the horizontal plane with age in groups A, B and C (P < .05), and with a constant angle to the coronal plane among the four groups (P > .05). The bony and cartilaginous segments of ET exhibit distinct morphological changes in space with age. The bony segment of ET extends in a constant position from infancy to adulthood. In contrast, the cartilaginous segment of the ET indicates multidimensional positional changes until adulthood, in addition to the elongation from infancy to children. This may provide an accurate morphological basis for comparing the differences in ETD pathogenesis and surgical treatment between children and adults.

Clinical and computed tomography findings in cats with nasopharyngeal stenosis.

Concurrent anomalies are often found in nasopharyngeal stenosis and choanal atresia; some seem to be of primary nature, whereas others may be coincidental. This study aimed to report the computed tomography features and related comorbidities of these diseases. A cross-sectional retrospective study was performed using case and control groups defined according to the presence of signs of upper airway disease and the presence/absence of nasopharyngeal stenosis, respectively. The inclusion criteria were full-head tomography scans and access to clinical records. The exclusion criteria were brachycephalic breed, head trauma and neoplasm. Clinical and computed tomographic findings and relevant comorbidities were recorded. Forty-three cats were included, 23 cases and 20 controls. The case group was significantly younger, had more paranasal sinus anomalies and never had turbinate lysis, also, had significantly more soft palate anomalies, which was significantly shorter. Nasopharyngeal stenosis varied from membrane appearance to partial or complete adhesion of the soft palate to the nasopharynx, was mainly located in the caudal region of the nasopharynx and was imperforated in approximately half of the cases. Imperforated membranes were significantly thicker in the sagittal plane and were significantly associated with nasal obstruction and soft tissue attenuation of the tympanic bulla. Hiatal hernia and ventricular asymmetry were only encountered in three and two cases, respectively, with nasopharyngeal stenosis. Computed tomography in cats with nasopharyngeal stenosis can identify concurrent anomalies, can help to differentiate a possible choanal atresia and evaluate the magnitude of its significance.

Comparing novel smartphone pose estimation frameworks with the Kinect V2 for knee tracking during athletic stress tests.

To compare the accuracy of the Microsoft Kinect V2 with novel pose estimation frameworks, in assessing knee kinematics during athletic stress tests, for fast and portable risk assessment of anterior cruciate ligament (ACL) injury. We captured 254 varsity athletes, using the Kinect V2 and a smartphone application utilizing Google's MediaPipe framework. The devices were placed as close as possible and used to capture a person, facing the cameras, performing one of three athletic stress tests at a distance of 2.5ms. Custom software translated the results from both frameworks to the same format. We then extracted relevant knee angles at key moments of the jump and compared them, using the Kinect V2 as the ground truth. The results show relatively small angle differences between the two solutions in the coronal plane and moderate angle differences on the sagittal plane. Overall, the MediaPipe framework results seem to underestimate both knee valgus angles and knee sagittal angles compared to the Kinect V2. This preliminary study demonstrates the potential for Google's MediaPipe framework to be used for calculating lower limb kinematics during athletic stress test motions, which can run on most modern smartphones, as it produces similar results to the Kinect V2. A smartphone application similar to the one developed could potentially be used for low cost and widespread ACL injury prevention.

Combined Direct and Indirect Revascularisation With Superficial Sparing of Temporalis Muscle in Moyamoya Disease: Operative Technique: 2-Dimensional Operative Video.

The primary objective of revascularization surgery for moyamoya disease (MMD) is to augment cerebral blood flow and prevent disease progression.1 There are several options for bypass surgery, including direct methods such as superficial temporal artery-middle cerebral artery anastomosis, indirect bypasses such as encephalomyosynangiosis, encephaloduroarteriosynangiosis or encephaloduroarteriomyosynangiosis, or combined procedures.2-5 In our institution, we undertake a combined approach involving multiple low-flow bypasses and a modified indirect bypass technique, with additional attention to achieving an optimal cosmetic result. Given that MMD often affects young patients, considering cosmesis as a significant factor in managing this condition should be standard practice. We present our modified operative technique of a combined approach to revascularization surgery in patients with MMD with particular emphasis on the indirect bypass procedure. The temporalis muscle is divided in two parts in the sagittal plane where the deeper portion is mobilized to perform an EMS, and the superficial portion is reattached to the bone flap to maintain cosmetic symmetry. A 23-year-old woman presented with a 6-month history of transient left-sided hemiparesis on a background of MMD (previous left-sided revascularization surgery). Subsequent imaging demonstrated worsening right internal carotid artery stenosis. The patient and her family were extensively counseled and decision to proceed with right-sided bypass surgery was undertaken (Video). The patient had an unremarkable postoperative course and was discharged home on day 14. Institutional review board approval was not required in our institution. The patient consented to the procedure and to the publication of his/her images.

Passive intervertebral restraint is different in patients with treatment-resistant chronic nonspecific low back pain: a retrospective cohort study and control comparison

PurposeIn vivo studies of continuous lumbar sagittal plane motion have found passive intervertebral motion to be more uneven in patients with chronic nonspecific low back pain (CNSLBP) than healthy controls, but the mechanisms are unclear. This study aimed to compare patients with CNSLBP with a matched group of pain-free controls for intervertebral restraint during passive recumbent bending.MethodsSeventeen patients with CNSLBP and minimal disc degeneration who had quantitative fluoroscopy investigations were matched to 17 healthy controls from a database acquired using the same imaging protocol. The entire database (n = 136) was examined for clustering of peaking times, magnitudes and ROM of the first derivatives of the intervertebral angle/motion curves (PTFD, PMFD and ROM) during flexion and return that might introduce confounding. The groups were then compared for differences in these variables.ResultsThere were significant segmental ROM differences among clusters in the database when PMFD and ROM were used as clustering variables, indicating heterogeneity. However, in the patient–control study, it was PTFD (velocity) that differentiated the groups. At L5-S1, this was at 10.82% of the motion path compared with 25.06% in the controls (p = 0.0002). For L4-5, PTFD was at 23.42% of the motion path in patients and 16.33% in controls (p = 0.0694) suggesting a reduced initial bending moment there. There were no significant differences for PMFD or ROM.ConclusionPeaking time of passive intervertebral velocity occurs early at L5-S1 in patients with CNSLBP; however, these findings should be treated with caution pending their replication. Future studies should explore relationships with altered disc pressures and biochemistry. Usefulness for monitoring regenerative disc therapies should be considered.

THE TEN-YEAR RADIOLOGICAL RESULTS OF THE UNCEMENTED OXFORD MEDIAL COMPARTMENT KNEE ARTHROPLASTY

IntroductionThe Oxford Unicompartmental Knee Replacement (OUKA) is the most popular unicompartmental knee replacement (UKR) in the New Zealand Joint Registry with the majority utilising cementless fixation. We report the 10-year radiological outcomes.MethodsThis is a prospective observational study. All patients undergoing a cementless OUKA between May 2005 and April 2011 were enrolled. There were no exclusions due to age, gender, body mass index or reduced bone density.All knees underwent fluoroscopic screening achieving true anteroposterior (AP) and lateral images for radiographic assessment. AP assessment for the presence of radiolucent lines and coronal alignment of the tibial and femoral components used Inteliviewer radiographic software. The lateral view was assessed for lucencies as well as sagittal alignment.Results687 OUKAs were performed in 641 patients. Mean age at surgery was 66 years (39–90yrs), 382 in males and 194 right sided. 413 radiographs were available for analysis; 92 patients had died, 30 UKRs had been revised and 19 radiographs were too rotated to be analysed the remainder were lost to follow-up. Mean radiograph to surgery interval was 10.2 years (7.1–16.2yrs).RLLs were identified in zone 1 (3 knees), zone 2 (2 knees), zone 3 (3 knees), zone 5 (3 knees), zone 6 (2 knees) and zone 7 (42 knees). No RLL had progressed, and no case had any osteolysis or prosthesis subsidence.Alignment in the coronal plane: mean 2.90° varus (9.30° varus - 4.49° valgus) of the tibial component to the tibial anatomic axis and the femoral component in mean 4.57° varus (17.02° varus - 9.3° valgus). Sagittal plane posterior tibial slope was a mean 6.30° (0.44° -13.60° degrees) and mean femoral component flexion of 8.11° (23.70° flexion – 16.43° extension).ConclusionThe cementless OUKA demonstrates stable fixation with low revision rates at our centre supporting results earlier published by the design centre.

How reliable are femoropelvic kinematics during deep squats? The influence of subject-specific skeletal modelling on measurement variability

BackgroundBiplanar radiography displays promising results in the production of subject-specific (S.specific) biomechanical models. However, the focus has predominantly centred on methodological investigations in gait analysis. Exploring the influence of such models on the analysis of high range of motion tasks linked to hip pathologies is warranted. The aim of this study is to investigate the effect of S.Specific modelling techniques on the reliability of deep squats kinematics in comparison to generic modelling. Methods8 able-bodied male participants attended 5 motion capture sessions conducted by 3 observers and performed 5 deep squats in each. Prior to each session a biplanar scan was acquired with the reflective-markers attached. Inverse kinematics of pelvis and thigh segments were calculated based on S.specific and Generic model definition. Agreement between the two models femoropelvic orientation in standing was assessed with Bland-Altman plots and paired t- tests. Inter-trial, inter-session, inter-observer variability and observer/trial difference and ratio were calculated for squat kinematic data derived from the two modelling approaches. ResultsCompared to the Generic model, the S.Specific model produced a calibration trial that is significantly offset into more posterior pelvis tilt (–2.8±2.7), hip extension (–2.2±3.8), hip abduction (–1.2±3.6) and external rotation (–13.8±11.4). The S.specific model produced significantly different squat kinematics in the sagittal plane of the pelvis (entire squat cycle) and hip (between 40 % and 60 % of the squat cycle). Variability analysis indicated that the error magnitude between the two models was comparable (difference<2°). The S.specific model exhibited a lower variability in the observer/trial ratio in the sagittal pelvis and hip, the frontal hip, but showed a higher variability in the transverse hip. SignificanceS.specific modelling appears to introduce a calibration offset that primarily translates into an effect in the sagittal plane kinematics. However, the clinical added value of S.specific modelling in terms of reducing experimental sources of kinematic variability was limited.

Stroke walking and balance characteristics via principal component analysis

Balance impairment is associated gait dysfunction with several quantitative spatiotemporal gait parameters in patients with stroke. However, the link between balance impairments and joint kinematics during walking remains unclear. Clinical assessments and gait measurements using motion analysis system was conducted in 44 stroke patients. This study utilised principal component analysis to identify key joint kinematics characteristics of patients with stroke during walking using average joint angles of pelvis and bilateral lower limbs in every gait-cycle percentile related to balance impairments. Reconstructed kinematics showed the differences in joint kinematics in both paretic and nonparetic lower limbs that can be distinguished by balance impairment, particularly in the sagittal planes during swing phase. The impaired balance group exhibited greater joint variability in both the paretic and nonparetic limbs in the sagittal plane during entire gait phase and during terminal swing phase respectively compared with those with high balance scores. This study provides a more comprehensive understanding of stroke hemiparesis gait patterns and suggests considering both nonparetic and paretic limb function, as well as bilateral coordination in clinical practice. Principal component analysis can be a useful assessment tool to distinguish differences in balance impairment and dynamic symmetry during gait in patients with stroke.

Central cone design demonstrates greater micromotion compared to keel design in cementless tibial baseplates: A biomechanical analysis.

The purpose of this study was to compare micromotion of two new cementless tibial baseplates to a cementless design with well-published clinical success. Three cementless tibial baseplate designs (fixed-bearing [FB] with keel and cruciform pegs, rotating-platform with porous central cone and pegs, FB with cruciform keel and scalloped pegs) were evaluated on sawbone models. Loading was applied to the baseplate at a rate of 1 Hz for 10,000 cycles, which represents 6-8weeks of stair descent. This time frame also represents the approximate time length for the induction of biologic fixation of cementless implants. Compressive and shear micromotion at the sawbone-implant interface were measured. At the end of the loading protocol, the central cone rotating-platform design exhibited greater micromotion at the anterior (p < 0.001), posterior (p < 0.001)and medial locations (p = 0.049) compared to the other two implants. The central cone design also exhibited greater translational micromotion in the sagittal plane at the medial (p = 0.001) and lateral locations (p = 0.034)and in the coronal plane anteriorly (p = 0.007). The cementless central cone rotating-platform baseplate demonstrated greater vertical and translational micromotion compared to the two FB baseplates with a keel underloading. This may indicate lower initial mechanical stability in implants without a keel, which possibly affects osseointegration. The implication of this is yet unknown and requires further long-term clinical follow-up to correlate these laboratory findings. V (biomechanical study).

SynergyAnalyzer: A Matlab toolbox implementing mixed-matrix factorization to identify kinematic-muscular synergies

Background and ObjectiveA new direction in the study of motor control was opened about two decades ago with the introduction of a model for the generation of motor commands as combination of muscle synergies. Muscle synergies provide a simple yet quantitative framework for analyzing the hierarchical and modular architecture of the human motor system. However, to gain insights on the functional role of muscle synergies, they should be related to the task space. The recently introduced mixed-matrix factorization (MMF) algorithm extends the standard approach for synergy extraction based on non-negative matrix factorization (NMF) allowing to factorize data constituted by a mixture of non-negative variables (e.g. EMGs) and unconstrained variables (e.g. kinematics, naturally including both positive and negative values). The kinematic-muscular synergies identified by MMF provide a direct link between muscle synergies and the task space. In this contribution, we support the adoption of MMF through a Matlab toolbox for the extraction of kinematic-muscular synergies and a set of practical guidelines to allow biomedical researchers and clinicians to exploit the potential of this novel approach. MethodsMMF is implemented in the SynergyAnalyzer toolbox using an object-oriented approach. In addition to the MMF algorithm, the toolbox includes standard methods for synergy extraction (NMF and PCA), as well as methods for pre-processing EMG and kinematic data, and for plotting data and synergies. ResultsAs an example of MMF application, kinematic-muscular synergies were extracted from EMG and kinematic data collected during reaching movements towards 8 targets on the sagittal plane. Instructions and command lines to achieve such results are illustrated in detail. The toolbox has been released as an open-source software on GitHub under the GNU General Public License. ConclusionsThanks to its ease of use and adaptability to a variety of datasets, SynergyAnalyzer will facilitate the adoption of MMF to extract kinematic-muscular synergies from mixed EMG and kinematic data, a useful approach in biomedical research to better understand and characterize the functional role of muscle synergies.

Kinematics of 90° change of direction in young football players: Insights for ACL injury prevention from the CUTtheACLstudy on 6008 trials.

To investigate the 90° change of direction (COD) task in an extensive cohort of competitive healthy football players within the CUTtheACLstudy and to provide normative values and differences between males and females for full-body kinematics based on two-dimensional (2D) video analysis and scoring system. One-thousand-and-two competitive football (soccer) players (age 16.3 ± 2.8 years, 264 females) were prospectively enroled. Each player performed three preplanned 90° COD tasks per limb. The 2D evaluation was performed through objective measures (collected through three high-speed cameras) of frontal and sagittal plane joint kinematics at the cut initial foot contact (IC) and maximum knee flexion angle. A previously published scoring system was adopted to measure the movement quality of the COD task. The scoring system included five criteria (limb stability [LS], pelvis stability [PS], trunk stability [TS], shock absorption [SA], movement strategy [MS]) ranked from 0/2 (nonadequate) to 2/2 (adequate) with a maximum score of 10/10. Normative data were provided for all the variables; statistical differences between male and female players were investigated (p < 0.05). A total of 6008 valid attempts were included. Frontal plane knee projection angle (FPKPA) at initial contact was 24.4 ± 9.8° (95thpercentile: FPKPA > 40°). The total score was ≤4/10 in 71.2% of the trials, the lowest subscores were LS and PS. Female players showed different movement patterns with lower hip and trunk flexion both at IC and maximum knee flexion angle (p < 0.01, ES = 0.41-0.64). Female players also showed worse scores than males in SA, MSand total score (p < 0.01). Female players seem more prone to stiffer lower limb strategy and greater pelvis-trunk frontal plane instability than males. Clinicians could adopt normative data and sex-specific differences in players' movement techniques to improve ACL injury risk mitigation protocols. Level IV.

Morphometric Analysis of the Sella Turcica on Cone-Beam Computed Tomography Images.

Sella turcica is an important anatomic formation that contains the pituitary gland and is in a close neighborhood with many vital structures. It is important to know the morphometry of the sella turcica, as it is a transition point during surgical interventions such as the endoscopic endonasal transsphenoidal approach to the region. The findings obtained are thought to be useful in the examination of sella turcica and surrounding structures and will contribute to the literature by knowing the morphometry of the region for the surgical method. In this study, cone-beam computed tomography images of 400 individuals, 200 females and 200 males, aged between 18 and 65 years, who did not have craniofacial pathology, who applied to Gaziantep University, Faculty of Dentistry between 2015 and 2020 for any reason, were evaluated retrospectively. In the sagittal section, 8 parameters were examined, 6 of which were transverse. The length () of the sella turcica in the sagittal plane is 10.19±1.77mm, the diameter of the sella turcica is 11.6±1.69mm, the anterior height of the sella turcica is 7.88±1.56mm, the median height of the sella turcica 8.18±1.42mm, posterior height of sella turcica 6.98±1.31mm, width of sella turcica 11.10±1.6mm. The distance between anterior clinoid processes in the transverse plane was 24.93±2.57mm, and the distance between posterior clinoid processes was 14.92±2.46mm. It was determined that there was an increase in many parameters with age, and length of the sella turcica and anterior clinoid processes were statistically significantly higher in males.

A new configuration of lateral-pin fixation for pediatric supracondylar humeral fracture: A biomechanical analysis.

The aim of this study was to biomechanically compare a new lateral-pinning technique, in which pins engage the medial and lateral columns of the distal humerus in a divergent configuration in both the axial and sagittal planes instead of the coronal plane, with the cross-pin, and with 2 and 3 coronally divergent lateral-pin techniques in a synthetic humerus model of supracondylar humerus fractures. Thirty-six identical synthetic models of the humerus simulating a standardized supracondylar humerus fracture were included in this study. They were divided into 4 groups based on the pin configuration of fixation: the new 3-lateral pin-fixation technique (group A), 2 crossed pins (group B), 3 divergent lateral pins (group C), and 2 divergent lateral pins (group D). Each model was subjected to combined axial and torsional loading, and then torsional stability and torsional stiffness (Nmm/°) were recorded. Group A had greater rotational stability than groups C and D but had no statistically significant additional rotational stability compared with group B (P=.042, P=.008, P=.648, respectively), whereas group B had greater rotational stability than only group D (P=.020). Furthermore, group A demonstrated higher internal rotational stiffness compared with groups C and D (P=.038, P=.006, respectively). Group B had better internal rotational stiffness than group D (P=.015). There was no significant difference in internal rotational stiffness between groups A and B (P=. 542), groups B and C (P=.804), and groups D and C (P=.352). Although no statistically significant differences existed between groups A and B, the modified pin configuration exhibited the highest torsional stability and stiffness. Group D showed the lowest values in all biomechanical properties. This study has shown us that this new lateral-pinning technique may provide torsional resistance to internal rotational displacement as strong as the standard technique of crossed-pin configuration of fixation. Furthermore, with this new pin configuration, greater torsional resistance can be obtained than with either the standard 2- or the standard 3-lateral divergent pin configuration. Cite this article as: Bilgili F, Demirel M, Birişik F, Balcı Hİ, Sunbuloglu E, Bozdag E. A new configuration of lateral-pin fixation for pediatric supracondylar humeral fracture: A biomechanical analysis. Acta Orthop Traumatol Turc., 2023 10.5152/j.aott.2024.21091 [Epub Ahead of Print].

An automated method for assessing condyle head changes in patients with skeletal class II malocclusion based on CBCT images.

Currently, there is no reliable automated measurement method to study the changes in the condylar process after orthognathic surgery. Therefore, this study proposes an automated method to measure condylar changes in patients with skeletal class II malocclusion following surgical-orthodontic treatment. Cone-beam computed tomography (CBCT) scans from 48 patients were segmented using the nnU-Net network for automated maxillary and mandibular delineation. Regions unaffected by orthognathic surgery were selectively cropped. Automated registration yielded condylar displacement and volume calculations, each repeated three times for precision. Logistic regression and Linear regression were used to analyze the correlation between condylar position changes at different time points. The Dice score for the automated segmentation of the condyle was 0.971. The Intraclass correlation coefficients (ICCs) for all repeated measurements ranged from 0.93 to 1.00. The results of the automated measurement showed that 83.33% of patients exhibited condylar resorption occurring six months or more after surgery. Logistic regression and Linear regression indicated a positive correlation between counterclockwise rotation in the Pitch plane and condylar resorption(p < 0.01). And a positive correlation between the rotational angles in both three planes and changes in the condylar volume at six months after surgery(p ≤ 0.04). This study's automated method for measuring condylar changes shows excellent repeatability. Skeletal class II malocclusion patients may experience condylar resorption after bimaxillary orthognathic surgery, and this is correlated with counterclockwise rotation in the sagittal plane. This study proposes an innovative multi-step registration method based on CBCT, and establishes an automated approach for quantitatively measuring condyle changes post-orthognathic surgery. This method opens up new possibilities for studying condylar morphology.

Abnormal Static Sagittal Cervical Curvatures following Motor Vehicle Collisions: A Retrospective Case Series of 41 Patients before and after a Crash Exposure.

Three spine clinic records were reviewed over a 2-year period, looking for patients where both an initial lateral cervical X-ray and an examination were performed prior to the patient being exposed to a MVC; afterwards, an additional exam and radiographic analysis were obtained. A total of 41 patients met the inclusion criteria. Examination records of pain intensity on numerical pain rating scores (NPRS) and neck disability index (NDI), if available, were analyzed. The CLRs were digitized and modeled in the sagittal plane using curve fitting and the least squares error approach. Radiographic variables included total cervical curve (ARA C2-C7), Chamberlain's line to horizontal (skull flexion), horizontal translation of C2 relative to C7, segmental translations (retrolisthesis and anterolisthesis), and circular modelling radii. There were 15 males and 26 females with an age range of 8-65 years. Most participants were drivers (28) involved in rear-end impacts (30). The pre-injury NPRS was 2.7 while the post injury was 5.0; p < 0.001. The NDI was available on 24/41 (58.5%) patients and increased after the MVC from 15.7% to 32.8%, p < 0.001. An altered cervical curvature was identified following exposure to MVC, characterized by an increase in the mean radius of curvature (265.5 vs. 555.5, p < 0.001) and an approximate 8° reduction of lordosis from C2-C7; p < 0.001. The mid-cervical spine (C3-C5) showed the greatest curve reduction with an averaged localized mild kyphosis at these levels. Four participants (10%) developed segmental translations that were just below the threshold of instability, segmental translations < 3.5 mm. The post-exposure MVC cervical curvature was characterized by an increase in radius of curvature, an approximate 8° reduction in C2-C7 lordosis, a mild kyphosis of the mid-cervical spine, and a slight increase in anterior translation of C2-C7 sagittal balance. The modelling result indicates that the post-MVC cervical sagittal alignment approximates a second-order buckling alignment, indicating a significant alteration in curve geometry. Future biomechanics experiments and clinical investigations are needed to confirm these findings.

Towards flow field measurements around dynamic cross-country skiers

Flow field measurements around cross-country skiers (xc skiers) are lacking in the literature to date. The aim was therefore to investigate the possibility of using particle tracking velocimetry for visualization and measurement of the flow field around xc skiers roller skiing on a treadmill in a wind tunnel. The airflow was seeded with neutrally buoyant helium-filled soap bubbles as tracer particles, following the flow without affecting it. As illumination, two different approaches were tested: first, a laser in the cameras’ line of sight (sagittal plane), then an LED unit directed vertically in a narrow slice, clearly limiting the depth of the measurement volume in the cameras’ line of sight. The flow field was studied at various speeds (3-7 m/s) around a single skier as well as around two skiers in line with the streaming airflow. It was found that the experimental approach has the potential to provide detailed insights, both qualitatively and quantitatively, into the flow field dynamics. The main challenges regarding setup, illumination, seeding, and cameras were identified, and possible improvements to streamline the experimental methodology were discussed.