Sagittal Research Articles

Range of international surgical strategies for adolescent idiopathic scoliosis: Evaluation of a multi-center survey.

Surgical treatment of adolescent idiopathic scoliosis (AIS) is very complex and modern instrumentation techniques offer multiple possibilities. Despite numerous publications, there is no clear consensus on the optimal strategy for the correction of scoliotic deformities. The goal of this study was to summarize the current surgical strategies for specific AIS cases within various countries. Thirty-two experienced scoliosis surgeons from 15 countries were asked to plan surgeries on 12 representative AIS cases. All AIS cases had an indication for surgery. A questionnaire was provided to document surgical planning. The surgeons were provided with the patients' age and sex, together with radiographs in the lateral and sagittal planes during upright standing and in lateral bending to the left and right, as well as with clinical images. The angles of the main spinal curvatures were specified in the questionnaire. The surgeons were asked to specify their preferred classification system, their surgical approach, the planned fusion length, the type of implants, the rod type, and the resection steps. The data were analyzed with respect to the inter-rater variability, which was quantified using the Fleiss-Kappa Method. There was a good agreement (k = 0.61) between the surgeons in choosing the Lenke curve type, and a moderate agreement for the lumbar (0.41) and sagittal (0.56) modifiers. The most frequently planned resection procedure was complete facetectomy (67%). The posterior approach was the most commonly (91%) selected strategy to treat AIS. Anterior approaches were chosen most for Lenke 5 type with a rate of 20%. The upper instrumented vertebra (UIV) varied most for Lenke 1, 5, and 6 cases, with a vertebral level discrepancy of up to 10 levels at Lenke 6. The lowest instrumented vertebra varied most for Lenke 1 and 4 by up to five levels. Polyaxial screws were chosen most (56%), followed by monoaxial (20%) and uniplanar (19%) screws and hooks (5%). The results highlight the commonalities and discrepancy in the surgical treatment of AIS in between surgeons. The selected LIV and UIV can vary depending on the curve type and surgeon. Hook constructs appear to be generally replaced by transpedicular screws. The survey indicates open questions in the AIS treatment and in the understanding of scoliosis biomechanics.

Women’s memory of episiotomy experience from 2 months to 2 years after birth in Orlu Imo State

Episiotomy procedures are defined based on the millimetre distance from the incision point to the posterior fourchette and the angle in degrees from the sagittal or parasagittal plane. This study examined Women's Memory of Episiotomy Experience from 2 Months to 2 Years after Birth in Orlu of Imo State. The study employed a qualitative survey design with four research questions. The sample size of 57 participants was selected, convenience sampling technique was used to select the respondents, the respondent were thus; women who underwent episiotomy 25, Midwives 8, family members 24. Data were collected using one on-one interview, via recordings. Data was analysed using percentages, barcharts and content analysis approach and thematic categorization. The results revealed 60% of the respondents come from low socioeconomic background. The study further revealed that; the challenges women experience within 2 months to 2 years as result of episiotomy were pain, inability to breast feed; due to inability to sit well, inability to walk freely, the perceived impact of episiotomy on women within the first 2 months to 2 years after birth were inability to have sex as usual. In conclusion, women were inadequately informed and not psychologically prepared for episiotomy, the respondent’s experienced untoward effect after the procedure which included: pain, and interference with daily life activities. Therefore, the study recommends that healthcare providers, especially midwives, to seek alternatives to routine use of episiotomy, and consider selective episiotomy practices based on individual patient need and thus educate pregnant mothers on perineal massage using recommended oil.

Preoperative evaluation of femoral and tibial sagittal alignment in robotic-assisted and conventional total knee arthroplasty and consequences for practice.

Robot-assisted total knee arthroplasty (TKA) was developed to improve the precision and accuracy of implant placement in conventional TKA. However, the angular differences between referenced axes in robot-assisted TKA and conventional TKA remain unclear. The aim of this study was to investigate the angular differences in sagittal alignment between robot-assisted TKA and conventional TKA for both the femur and the tibia and to discuss their clinical implications. We conducted a retrospective analysis of data from 100 patients (97 patients) who underwent computed tomography (CT) for Mako TKA. We measured the angle between the robot femoral axis (RFA) and conventional femoral axis (CFA) in the sagittal plane and the angle between the robot tibial axis (RTA) and the conventional tibial axis (CTA). Angles were compared between the sexes. Correlation analysis was conducted between the angles and height. In the sagittal plane, the mean RFA-CFA angle was 2.2° ± 1.6°, and the mean RTA-CTA angle was 2.3° ± 1.6°. There were no significant differences between the two angles among males and females (p > 0.05). There was a correlation between the RFA-CFA angle and RTA-CTA angle (p < 0.001, r = 0.33), and there was a correlation between height and the combination of the RFA-CFA angle and RTA-CTA angle (p = 0.03, r = 0.22). There are angular differences between the axes referenced by robot-assisted TKA and those referenced by conventional TKA, which may be influenced by patient height. Correctly understanding these differences is crucial when evaluating the implant position and surgical outcomes after robot-assisted TKA. Furthermore, caution should be taken when assessing the flexion-extension angle of the knee since the angles displayed in the Mako system are different from the angles measured with intramedullary anatomical axes. After all, sagittal alignment principles differ between robot-assisted and conventional TKA; however, further studies are required to determine which principle is more appropriate or to modify these principles.

Lower Limb Muscle Co-Activation Maps in Single and Team Lifting at Different Risk Levels

The central nervous system uses muscle co-activation for body coordination, effector movement control, and joint stabilization. However, co-activation increases compression and shear stresses on the joints. Lifting activity is one of the leading causes of work-related musculoskeletal problems worldwide, and it has been shown that when the risk level rises, lifting enhances trunk muscle co-activation at the L5/S1 level. This study aims to investigate the co-activation of lower limb muscles during liftings at various risk levels and lifting types (one-person and vs. two-person team lifting), to understand how the central nervous system governs lower limb rigidity during these tasks. The surface electromyographic signal of thirteen healthy volunteers (seven males and six females, age range: 29–48 years) was obtained over the trunk and right lower limb muscles while lifting in the sagittal plane. Then co-activation was computed according to different approaches: global, full leg, flexor, extensor, and rostro-caudal. The statistical analysis revealed a significant increase in the risk level and a decrease in the two-person on the mean and/or maximum of the co-activation in almost all the approaches. Overall, our findings imply that the central nervous system streamlines the motor regulation of lifting by increasing or reducing whole-limb rigidity within a distinct global, extensor, and rostro-caudal co-activation scheme, depending on the risk level/lifting type.

Effect of Cervical and Shoulder Complex Exercises on Improvement of Forward Head Posture

Background: Forward head posture is anterior positioning of the head with respect to neck in sagittal plane. Craniovertebral angle is used to measure forward head posture. Craniovertebral angle is formed at the junction of a line drawn from the tragus of the ear through the spinous process of the C7 vertebra and a horizontal line through the C7 vertebra. This study aimed to investigate the effects of cervical and shoulder complex exercises on improvement of forward head posture. Objectives: To improve the forward head posture by- Cervical and shoulder complex exercises. Method: 30 participants, whose craniovertebral angle (CVA) was less than 50° were selected and further divided into experimental group (Group-A) (15 participants) and control group (Group- B) (15 participants). Photos of participants in standing position were taken using mobile camera and craniovertebral angle was measured using autocad software. Experimental group performed exercises such as chin tucks, cervical posterior isometric, scapular retraction exercise, Y to W exercise, middle trapezius fibres muscle strengthening exercise for 6 week interval. Whereas the control group was asked to carry on with routine activities. Pre (0th week ), mid (4th week), and post (6th week ) photos of participants of both groups were taken to see the effect of exercises along with numerical pain rating and neck disability score Results: This study signified that craniovertebral angle (p value=0.001), numerical pain rating scale score ( p value=0.001) and neck disability index scores (p value=0.001) were statistically significant. Conclusion: This study proved that 6 week cervical and shoulder complex exercises protocol has significant effect in improving forward head posture and reducing neck pain and neck disability. Keywords: Autocad software, Craniovertebral angle, chin tucks, forward head posture, neck pain, neck disability

Evaluation of In-Brace Coronal and Sagittal Plane Measurements Between CAD/Chêneau-Style and Traditionally Fabricated Wilmington Braces in Adolescent Idiopathic Scoliosis

ABSTRACT Introduction Traditional thoracolumbosacral orthosis fabrication involves truncal casting (traditionally fabricated [TF] Wilmington brace [WB]), whereas the newer Chêneau-style brace (computer-aided design [CAD]) involves three-dimensional truncal scanning technology. We sought to evaluate how these two brace styles affect the position of the spine in the coronal and sagittal plane. Materials and Methods Inclusion criteria included adolescent idiopathic scoliosis treated with WB or CAD Chêneau-style brace, major curve Cobb angle 20°–45°, age 10–15 years, Risser 0–3, and radiographs (prebrace and in-brace posteroanterior and lateral). Analysis included 28 CAD Chêneau-style braces and 56 WB patients. Results There was no difference between groups regarding age, sex, body mass index, major curve location, major curve degree, sagittal plane curvature, and pelvic parameters. In-brace analysis demonstrated decreased sagittal plane curvatures and increased T1 pelvic angle in both groups; both had significantly reduced major curve correction. Coronal plane major curve correction ratio of the two groups was similar (P = 0.236). In the CAD Chêneau-style brace group, the thoracolumbar junction became more kyphotic (P = 0.03). In the WB group, both coronal balance and thoracic trunk shift were leftward (P = 0.001). Both groups had a significant increase in T1 pelvic angle, but this increase was higher in the CAD Chêneau-style brace group (P = 0.045). Conclusions Both braces exert a flattening effect on the spine and positive global sagittal balance. Coronal plane major curve correction was similar for both groups. Coronal plane trunk shift and C7 coronal balance were significantly changed leftward after WB application. Kyphotic thoracolumbar transition and forward tilt of the spine (T1 pelvic angle) were significantly greater in CAD Chêneau-style brace than WB. Clinical Relevance A Chêneau-style brace fabricated with CAD/computer-aided manufacturing technology can produce a brace comparable to one fabricated by traditional methods using cast molding.

Morphometric Study of Lumbar Vertebral Pedicles by Using Computed Tomography among Adults in Kano, Nigeria

Abstract Context: Precise anatomical knowledge of lumbar pedicle dimensions is necessary to make a clinical diagnosis of lower back pain, and any structural deviation of the pedicles may result in interference with the weight transmission mechanism and compression of neural structures. Aim: To evaluate the morphometric dimensions of lumbar vertebral pedicles among normal adults in Kano by using computerized tomography scan images. Materials and Method: This was a hospital-based cross-sectional study that was conducted in the radiology department of Aminu Kano Teaching Hospital (AKTH). This study was conducted over 1 year and included 110 adults aged 18–75 years involving both sexes in Kano, using their CT scan images from L1 to L5, following IRB ethics approval. Each vertebral pedicle was measured in transverse and sagittal planes. The measurements included the pedicle width (PW), sagittal pedicle height (SPH), and the pedicle chord length (PCL) of individual pedicles. The mean and standard deviations for each measurement parameter were determined, and parametric correlation tests were performed to determine the relationships between age, sex, and ethnicity. Statistical Analysis Used: Data analysis was performed using the statistical software package IBM SPSS Statistics version-23 for Windows. The significance level was considered at P &lt; 0.05. Results: Mean PW size increased craniocaudally along the lumbar spine from L1 (7.49 ± 1.52 mm) to L5 (14.31 ± 1.93 mm). A gradual decrease in mean SPH sizes from L1 (14.53 ± 1.32 mm) to L5 (11.73 ± 1.38 mm) was noted, while mean PCL showed an irregular “U” pattern, with the smallest size at L4 (44.63 ± 3.42 mm) and highest at L2 (46.80 ± 3.85 mm). All measured dimensions were significantly higher in the right pedicles and among male subjects (P &lt; 0.05). Age and ethnicity did not consistently affect pedicle dimensions (P &gt; 0.05). Conclusion: This study observed right pedicle dimensions and male subjects as having significantly larger pedicle diameters, with age and ethnicity not having a significant effect on pedicle sizes across all vertebral levels.

Lower extremity joint angle, moment, and coordination throughout a double limb drop vertical jump in individuals with anterior cruciate ligament reconstruction

ABSTRACT Individuals with anterior cruciate ligament reconstruction (ACLR) utilise different landing biomechanics between limbs, but previous analyses have not considered the continuous or simultaneous joint motion that occurs during landing and propulsion. The purpose of this study was to compare sagittal plane ankle/knee and knee/hip coordination patterns as well as ankle, knee, and hip angles and moments and vertical ground reaction force (vGRF) between the ACLR and uninjured limbs during landing and propulsion. Fifteen females and thirteen males performed a drop vertical jump from a 30 cm box placed half their height from force platforms. Coordination was compared using a modified vector coding technique and binning analysis. Kinematics and kinetics were time normalised for waveform analyses. Coordination was not different between limbs. The ACLR limb had smaller dorsiflexion angles from 11 to 16% of landing and 24 to 75% of landing and propulsion, knee flexion moments from 5 to 15% of landing, 20 to 31% of landing, and 35 to 91% of landing and propulsion, and vGRF from 92 to 94% of propulsion compared with the uninjured limb. The ACLR limb exhibited smaller dorsiflexion angles to potentially reduce the knee joint moment arm and mitigate the eccentric and concentric demands on the ACLR knee during landing and propulsion, respectively.

Design and Evaluation of Kirschner Wire Guide Device for Patellar Fracture Fixation

Abstract Identifying the optimal position for Kirschner wire (K-wire) is crucial in tension band wiring for patellar fracture. This study analyzed the ideal position and designed a guide device to aid precise K-wire insertion. The stress and displacement at 90&amp;amp;amp;#176; of flexion were compared to determine the optimal positions. The number of insertions and fluoroscopies, and operating times were recorded in a retrospective study. Intraoperative radiographs were used to measure the K-wire position relative to the patella in the coronal and sagittal planes to assess accuracy. The least stability occurred when the distance between the K-wires was 1/2 of the patellar width in the coronal plane and close to the patellar anterior surface. The number of K-wire insertions in the experimental group and control group (1.33 ±0.58 vs 3.8 ±1.03; P = 0.009), the number of fluoroscopies (2.67 ±0.58 vs 10 ±1.33; P = 0.007), and the operating time (55 ±8.66 min vs 82 ±9.49 min; P = 0.001) were significantly different. K-wires should parallel to each other, spaced 1/4 or 1/3 of the patellar width in the coronal plane, and 1/2 to 3/4 of the patellar thickness in the sagittal plane away from the patellar anterior surface. The surgeon could improve insertion accuracy with guide device.

Value of arthroscopy in the management of acute lesions of the distal tibiofibular joint.

Managing the distal tibiofibular (DTF) joint remains a challenge despite recent developments. Ankle arthroscopy is emerging as a diagnostic and therapeutic means. Our study aimed to compare preoperative imaging data and arthroscopic data, with the hypothesis that imaging alone is insufficient to evaluate acute laxity, and with arthroscopy as the reference examination. All patients treated in 2023 in our department for an acute isolated DTF lesion were included prospectively. Preoperative radiographic and MRI imaging were compared with arthroscopic data. Ten patients were treated. For five patients, the instability was doubtful after carrying out an appropriate imaging assessment (X-rays of both ankles, MRI). For four of these five patients, instability was confirmed by arthroscopy. Arthroscopy was useful for suturing the anterior bundle of the DTF joint for two patients and allowed for verifying the reduction in the sagittal and coronal planes for two patients. No complications were detected. Arthroscopy in isolated acute DTF lesions seems to provide a diagnostic and therapeutic advantage. Its use may allow for exhaustive assessment and complete repair of lesions. It must be offered as soon as possible; a delay in specialized imaging may delay therapeutic care.

Traditional versus dynamic sitting: Lumbar spine kinematics and pain during computer work and activity guided tasks

Dynamic sitting may mitigate low back pain during prolonged seated work. The current study compared pelvis and lumbar spine kinematics, pain, and work productivity, in traditional and dynamic sitting. Sixteen participants completed three 20-min blocks of computer work and activity guided tasks in a traditional office chair or backless and multiaxial rotating seat pan while kinematics were measured from accelerometers on the low back. Pain ratings were recorded on a visual analogue scale every 10 min. Similar pelvis and lumbar kinematics emerged when performing computer work in traditional and dynamic sitting. Pelvis and lumbar sagittal and frontal plane shifts and fidgets were largest for dynamic sitting in the activity guided tasks. Buttocks pain was higher in dynamic sitting, but low back pain and work productivity were unaffected. Dynamic sitting increased spine movement during activity guided tasks, without negatively impacting lumbar kinematics, low back pain, or productivity during seated computer work.

The CT Classification of Multilevel Cervical Ossification of the Posterior Longitudinal Ligament to Guide Hybrid Anterior Controllable Antedisplacement and Fusion vs. Posterior Laminoplasty.

For precise and minimally invasive treatment of ossification of the posterior longitudinal ligament of the cervical spine, the lifting segment is minimized, anterior controllable antedisplacement and fusion (ACAF) was refined and improved. In addition, the development of appropriate surgical procedures for the ossification of each segment was rarely reported. Therefore, this study aimed to compare the efficacy and safety of hybrid anterior controlled antedisplacement fusion (Hybrid ACAF) with laminoplasty for multilevel ossification of the posterior longitudinal ligament (OPLL). Between May 2018 and May 2021, 70 patients with multilevel OPLL were divided into a hybrid ACAF group and a laminoplasty group according to surgical methods. All patients were followed up for at least 1 year. Japanese Orthopaedic Association (JOA) score and recovery rate (JOARR), (VAS, NDI) score and C2-C7 Cobb angle, the sagittal vertical axis of the neck (SVA), and complications (cerebrospinal fluid leakage, C5 paralysis, etc.) were compared between the two groups by t test or non-parametric test. The operation time of hybrid ACAF was longer. C5 paralysis and axial pain were more common in the laminoplasty group, while dysphagia and hoarseness were more common in the hybrid ACAF group. At the last follow-up, the hybrid ACAF group had better recovery and maintenance of cervical lordosis and sagittal plane balance and a higher JOA score and recovery rate than the laminoplasty group. Hybrid ACAF can reduce the number of vertebral bodies and expand the decompression range, which is safe, effective, and tailored to local conditions. Compared with laminoplasty, hybrid ACAF is a precise alternative for patients with OPLL.

Evaluation of Cochlear Implantation in Children With Cochlear Nerve Absence or Deficiency.

To identify associations between cochleovestibular anatomy findings and hearing outcomes found in children with imaging evidence of an absent or hypoplastic cochlear nerve treated with cochlear implantation (CI). retrospective review. Cochlear implant program at tertiary care center. A retrospective review was performed to identify children with imaging evidence of cochlear nerve absence or deficiency who underwent CI evaluation. High-resolution 3-dimensional T2-weighted magnetic resonance imaging in the oblique sagittal and axial planes were reviewed by a neuroradiologist to identify cochleovestibular anatomy. Hearing was assessed pre and postoperatively with Speech Perception Category scores. Seven CI recipients were identified (n = 10 ears) who had bilateral severe to profound sensorineural hearing loss with lack of auditory development with binaural hearing aid trial and imaging evidence of cochlear nerve aplasia/hypoplasia. All ears had 2 nerves in the cerebellopontine angle (100%, n = 10), half of the ears had evidence of 2 or less nerves in the internal auditory canal (IAC). All children showed large improvement in speech perception after CI. Our experience with CIs for children with absent or hypoplastic cochlear nerves demonstrates that CI can be a viable option in select patients who satisfy preoperative audiological criteria. Radiological identification of a hypoplastic or aplastic cochlear nerve does not preclude auditory innervation of the cochlea. CI recipients in this subgroup must be counseled on difficulty in predicting postimplantation language and speech outcomes, and cautioned about facial nerve stimulation.

High in-vivo accuracy of a novel robotic-arm-assisted system for total knee arthroplasty.

Robotic-assisted total knee arthroplasty (TKA) has been shown to improve the accuracy and precision of bony resections and implant position. However, the in vivo accuracy of the full surgical workflow has not been widely reported. The primary objective of this study is to determine the accuracy and precision of a robotic-arm-assisted system throughout the intraoperative workflow. This was a retrospective cohort study of adult patients who underwent primary TKA with various workflows and alignment targets by three arthroplasty-trained surgeons with previous experience using the ROSA® Knee System (Zimmer Biomet) over a 3-month follow-up period. Accuracy and precision were determined by measuring the difference between various workflow time points, including the final preoperative plan (PP), robot-validated (RV) resection angleand postoperative radiographs (PR). The absolute mean difference between the measurements determined accuracy, and the standard deviation represented precision. The lateral distal femoral angle, medial proximal tibial angle, femoral flexion angle and tibial slope were measured on postoperative coronal long-leg radiographs and true short-leg lateral radiographs. A total of 77 patients were included in the final analyses. The accuracy for the coronal femoral angle was 1.62 ± 1.11°, 0.75 ± 0.79°and 1.96 ± 1.29° for the differences between PP and PR, PP and RVand RV and PR. The tibial coronal accuracy was 1.44 ± 1.03°, 0.81 ± 0.67°and 1.57 ± 1.14° for PP/PR, PP/RVand RV/PR, respectively. Femoral flexion accuracy was 1.39 ± 1.05°, 0.83 ± 0.59°and 1.81 ± 1.21° for PP/PR, PP/RVand RV/PR, respectively. Tibial slope accuracy was 0.99 ± 0.72°, 1.19 ± 0.87°and 1.63 ± 1.11°, respectively. The proportion of patients within 3° was 93.2%, 95.3%, 97.3%and 94.6% for the distal femur, proximal tibia, femoral flexionand tibial slope angles when the final intraoperative plan was compared to PRs. No patients had a postoperative complication at the final follow-up. The ROSA Knee System has acceptable accuracy and precision of coronal and sagittal plane resections with few outliers at various steps throughout the platform's entire workflow in vivo. Level III.

Automatic extraction of facial median sagittal plane for patients with asymmetry based on the EDMA alignment algorithm.

We aimed to establish a novel method for automatically constructing three-dimensional (3D) median sagittal plane (MSP) for mandibular deviation patients, which can increase the efficiency of aesthetic evaluating treatment progress. We developed a Euclidean weighted Procrustes analysis (EWPA) algorithm for extracting 3D facial MSP based on the Euclidean distance matrix analysis, automatically assigning weight to facial anatomical landmarks. Forty patients with mandibular deviation were recruited, and the Procrustes analysis (PA) algorithm based on the original mirror alignment and EWPA algorithm developed in this study were used to construct the MSP of each facial model of the patient as experimental groups 1 and 2, respectively. The expert-defined regional iterative closest point algorithm was used to construct the MSP as the reference group. The angle errors of the two experimental groups were compared to those of the reference group to evaluate their clinical suitability. The angle errors of the MSP constructed by the two EWPA and PA algorithms for the 40 patients were 1.39 ± 0.85°, 1.39 ± 0.78°, and 1.91 ± 0.80°, respectively. The two EWPA algorithms performed best in patients with moderate facial asymmetry, and in patients with severe facial asymmetry, the angle error was below 2°, which was a significant improvement over the PA algorithm. The clinical application of the EWPA algorithm based on 3D facial morphological analysis for constructing a 3D facial MSP for patients with mandibular deviated facial asymmetry deformity showed a significant improvement over the conventional PA algorithm and achieved the effect of a dental clinical expert-level diagnostic strategy.

Statistical Parametric Mapping to detect the effects of the secondary jump direction on landing kinematics

ABSTRACT Anterior cruciate ligament (ACL) injuries in sports often occur with non-contact mechanisms, such as landing and cutting. Previous studies explored the ACL injury biomechanical risk factors through drop-jumps combined with secondary jumps. This study aimed to investigate the effect of the secondary jump direction on first landing kinematic temporal series. Fifty-seven participants (29 males, 28 females) performed three single-leg drop-jumps followed by secondary jumps in vertical (single-planar), 45°-medial and 45°-lateral direction (multi-planar). Lower limb and trunk landing kinematics was recorded using a 9-camera motion capture system and analysed with a One-way ANOVA through Statistical Parametric Mapping (SPM), from initial contact to maximum knee flexion. All variables were affected by the secondary jump direction, except trunk rotation. In sagittal plane, kinematic main differences were found between single- and multi-planar tasks. The latter elicited higher trunk, hip, and knee flexion. Frontal plane kinematics was more influenced by medio-lateral components of secondary jumps. Our results could underline how a single task may be insufficient for ACL injury risk assessment. Single- and multi-planar tasks including a secondary jump should be considered for more comprehensive evaluations in prevention and rehabilitation programs, but caution should be used when comparing results of studies adopting different tasks.

Influence of Isolated Talonavicular and Subtalar Joint Arthrodesis on Hindfoot Kinematics and Range of Motion During Cadaveric Gait Simulation.

Isolated subtalar and talonavicular joint arthrodeses have been associated with adjacent joint arthritis and altered hindfoot kinematics during simplified loading scenarios. However, the effect on kinematics during dynamic activity is unknown. This study assessed changes in subtalar and talonavicular kinematics after isolated talonavicular (TNiso) and subtalar (STiso) arthrodesis, respectively, during stance simulations. Fourteen midtibia specimens received either a TNiso or STiso arthrodesis, with 7 randomized to each group. A 6-degree-of-freedom robot sequentially simulated the stance phase for the intact and arthrodesis conditions. Bootstrapped bias-corrected 95% CIs of the talonavicular and subtalar joint kinematics were calculated and compared between conditions. The TNiso decreased subtalar inversion, adduction, and plantarflexion in late stance (P < .05). The subtalar range of motion in the sagittal and coronal planes decreased by 40% (P = .009) and 46% (P = .002), respectively. No significant changes in talonavicular joint kinematics were observed after isolated subtalar arthrodesis; however, the range of motion was reduced by 61% (P = .007) and 50% (P = .003) in the coronal and axial planes, respectively. In this model for arthrodesis, changes in subtalar kinematics and motion restriction were observed after isolated talonavicular arthrodesis, and motion restriction was observed after isolated subtalar arthrodesis. Surprisingly, talonavicular kinematics did not appear to change after isolated subtalar arthrodesis. Both joint fusions substantially decrease the motion of the reciprocal adjacent joint. Surgeons should be aware that the collateral costs with talonavicular fusion appear higher, and it has a significant effect on subtalar kinematics during the toe-off phase of gait.

3D Models as a Source for Neuroanatomy Education: A Stepwise White Matter Dissection Using 3D Images and Photogrammetry Scans.

White matter dissection (WMD) involves isolating bundles of myelinated axons in the brain and serves to gain insights into brain function and neural mechanisms underlying neurological disorders. While effective, cadaveric brain dissections pose certain challenges mainly due to availability of resources. Technological advancements, such as photogrammetry, have the potential to overcome these limitations by creating detailed three-dimensional (3D) models for immersive learning experiences in neuroanatomy. This study aimed to provide a detailed step-by-step WMD captured using two-dimensional (2D) images and 3D models (via photogrammetry) to serve as a comprehensive guide for studying white matter tracts of the brain. One formalin-fixed brain specimen was utilized to perform the WMD. The brain was divided in a sagittal plane and both cerebral hemispheres were stored in a freezer at -20°C for 10 days, then thawed under running water at room temperature. Micro-instruments under an operating microscope were used to perform a systematic lateral-to-medial and medial-to-lateral dissection, while 2D images were captured and 3D models were created through photogrammetry during each stage of the dissection. Dissection was performed with comprehensive examination of the location, main landmarks, connections, and functions of the white matter tracts of the brain. Furthermore, high-quality 3D models of the dissections were created and housed on SketchFab®, allowing for accessible and free of charge viewing for educational and research purposes. Our comprehensive dissection and 3D models have the potential to increase understanding of the intricate white matter anatomy and could provide an accessible platform for the teaching of neuroanatomy.

Relationship between jump height and lower limb joint kinetics and kinematics during countermovement jump in elite male athletes

ABSTRACT This study aims to identify the relationship between jump height and the kinetic and kinematic parameters of the hip, knee, and ankle joints during countermovement jump (CMJ) in elite male athletes. Sixty-six elite male athletes from various sports (strength and power, winter downhill, combat, ball game, and aquatic) performed maximal effort CMJs with hands and arms crossed against their chests on force platforms. Jumping motion in the sagittal plane was recorded using video analysis and the peak torque, power, and angular velocity of the right hip, knee, and ankle joints were calculated during the propulsive phase. Correlations between the CMJ height and kinetic and kinematic parameters were investigated using Pearson’s product-moment coefficient (r) and Spearman’s rank correlation coefficient (ρ). CMJ height was highly correlated with peak hip power (ρ = 0.686, p < 0.001) and peak knee angular velocity (r = 0.517, p < 0.001), and moderately correlated with peak hip angular velocity (r = 0.438, p < 0.001) and peak hip torque (r = 0.398, p = 0.001). These results indicate that notable hip torque and power can contribute to increased angular velocity in both the knee and hip joints, ultimately increasing the CMJ height in elite male athletes.

Biceps femoris muscle-tendon strain during an entire overground sprint acceleration: a biomechanical explanation for hamstring injuries in the acceleration phase

ABSTRACT The objectives of this study were to analyse the peak muscle-tendon (MT) strain of the hamstring during an entire acceleration sprint overground and examine their relationship with relative joint angles and segment orientation in the sagittal plane, which are the direct causes of MT strain. Kinematic data were recorded using a 3D inertial motion capture system in 21 male semi-professional soccer players during 40-metre overground sprint. Scaled musculoskeletal models were used to estimate peak MT strain in the hamstring over 16 steps. Biceps femoris long head (BFLH) exhibited the largest peaks in MT strain compared to semitendinosus (ST) and semimembranosus (SM) muscles across all the steps, with its overall strain decreased as the number of steps and maximum speed increased. Hip flexion angle was found to be a strong predictor (p < 0.001) of joint angles, being the orientation of the pelvis in the sagittal plane of the segment with the greatest influence (p < 0.001) on the peak MT strain of BFLH during sprinting. The current study provides a biomechanical explanation for the high proportion of hamstring injuries in the acceleration phase of sprinting.