Sagittal Research Articles

Registration of jaw centric relation with different deprogramming devices

BACKGROUND: There are several methods to register jaw centric relation for diagnosis and therapy of dysfunctional disorders of the temporomandibular joint. However, there is insufficient information in the literature regarding the choice of the optimal way to determine this indicator. AIM: To compare different methods for recording jaw centric relation according to the data of the computed tomography of temporomandibular joint. MATERIALS AND METHODS: The study includes participants with increased abrasion of hard tooth tissues and symptoms of musculoskeletal dysfunction of the temporomandibular joint. The main group (80 people) has been recorded jaw centric relation using deprogramming devices (Lucia jig — 1stsubgroup, Kois deprogrammer — 2ndsubgroup, sheet calibrator — 3rd subgroup, deprogrammer in combination with M. Rocаbado kinesiotherapy elements — 4th subgroup). The control group included 20 participants, who had not had deprogramming before registration of jaw centric relation. The results were monitored using computed tomography of temporomandibular joint and subsequent assessment of the sizes of the TMG articular gap in the coronary and sagittal sections at 3 stages of the study: diagnostic, after registration of jaws central relation and prosthetic treatment and 6 months after prosthetic rehabilitation. Since there were no more than 50 observations in each group, the Shapiro–Wilk W-test was used to verify compliance with the norm. RESULTS: According to the data obtained, the parameters of the temporomandibular joint gap have changed in the main group of the 1th subgroup, where indicators are approaching the physiological norm (98% of cases). In the 2ndsubgroup, 90% of the participants show a tendency to conform to the physiological norm. The exception is 10% of the participants with no tendency of improvement. The smaller part (75%) of the participants of the 3rd subgroup observed compliance of the parameters of the articular gap with the criteria of the norm. The dimensions of the anterior part of the articular gap of the temporomandibular joint exceed the dimensions of the distal part, which indicates the anterior position of the temporomandibular joint. Some patients in this group (25%) showed no positive results of computed tomography measurements after jaws centric relation registration. In the 4th subgroup, the patients returned to normal values (100% of the cases). The positive effect of prosthetic treatment and restoration of the position of the articular heads of the temporomandibular joint were obtained in 45 % of the participants in the control group. However, in 55% of the participants the location of the articular gap of the temporomandibular joint did not improve. CONCLUSIONS: Lucia jig in combination with the M. Rokabado’s complex of cranial-postural kinesiotherapy is the most effective method to register jaw centric relation within this study. The remaining methods are also applied among prosthetic dentists and gnathologists. However, in each clinical situation, it is necessary to consider temporomandibular joint pathology indications, type and degree of severity as well as the technical and financial capacity of both doctor and patient.

Direct Vertebral Rotation versus Simple Rod Derotation Techniques in Correction of Adolescent Idiopathic Scoliosis

Abstract Background One method for treating adolescent idiopathic scoliosis (AIS), which is characterised by abnormal spinal alignment in the coronal, sagittal, and rotational planes, is surgical correction. The two surgical techniques most typically used to correct spine alignment are simple rod derotation (SRD) and direct vertebral rotation (DVR). Aim The study's goal was to assess the effectiveness of two treatment methods for adolescent idiopathic scoliosis: simple rod derotation and direct vertebral rotation. Subjects and Methods A randomised controlled research involving 36 adolescents with idiopathic scoliosis was done. patients were randomly split into one of two groups: 18 patients in group A had DVR treatment, while 18 patients in group B received SRD with a 2-year follow-up. Results Apical Vertebral Rotation measured from CT scans in DVR group was 24.4° ±8.38° preoperatively and it decreased significantly postoperatively to 14.4°±4.61 °with (42.22%) correction rate while in SRD group it was 25.03°±7.99° preoperatively and it also decreased significantly postoperatively to a mean value of 21.41°±7.01° with (14.65%) correction rate. There were statistically significant differences between both groups postoperative (P < 0.001) Conclusion The most noticeable difference between DVR and SRD was clinical rib hump correction, which was explained by apical vertebral rotation correction determined on an axial CT scan. It also demonstrates that there is no significant difference in coronal curve correction, shoulder height difference, or patient satisfaction between the two techniques.

Task-specific differences in lower limb biomechanics during dynamic movements in individuals with chronic ankle instability compared with controls

BackgroundChronic ankle instability (CAI) has been associated with lower limb deficits that can lead to altered biomechanics during dynamic tasks. There have been contradictory findings in terms of ankle and hip joint biomechanics to date, influenced by the variety of movement tasks and varying definitions of the CAI condition. Research QuestionHow do biomechanical variables of the lower extremity differ during walking, running, and jump-landing in individuals with CAI compared with those without CAI? MethodsThirty-two individuals (17 CAI and 15 controls) participated in this retrospective case-control study. Sagittal and frontal plane ankle and hip joint angles and moments, and mediolateral foot balance (MLFB) were calculated during the tasks. Statistical parametric mapping (SPM) was used for the whole trajectory analysis to detect group differences. Discrete variables, including initial contact (IC) and peak angles and moments, were additionally compared. ResultsNo differences were found between groups during walking. During running, the CAI group exhibited a lower plantar flexor moment (p < 0.001) and more laterally deviated MLFB (p = 0.014) during mid-stance when compared to controls. Additionally, participants with CAI had a significantly greater peak plantar flexion angle in early stance (p = 0.022) and a reduced peak plantar flexor moment (p = 0.002). In the jump-landing, the CAI group demonstrated an increased hip extensor moment (p = 0.008), and a greater peak hip adduction angle (p = 0.039) shortly after ground contact compared to the control group. SignificanceDifferences in ankle and hip biomechanics were observed between groups during running and jump landing, but not during walking. These differences may be indicative of impairments in the sensorimotor system or of learnt strategies adopted to try to minimise instability and injury risk and can help to inform future intervention design.

Open Reduction and Internal Fixation versus Minimally Invasive Plate Osteosynthesis in Management of Distal Tibia Extra-Articular Fracture (Mini Thesis)

Abstract Background Extra-articular distal tibia fracture is one of the difficult fractures to treat and the optimal treatment remains controversial, however plates seem to be the obvious choice for treating this type of fractures. The mechanism on how to achieve the balance between anatomic reduction and indirect reduction as well as direct and indirect healing remains unclear. Thus, the key point is whether to use ORIF or MIPO in treating fractures. Aim of the Work to provide a complete overview of the optimal plating technique for distal tibia fractures by evaluating and comparing the clinical and functional outcomes of minimally invasive plate osteosynthesis (MIPO) vs Open reduction and internal fixation (ORIF) for treating extra- articular distal tibial fractures. Outcomes of interest include operation time, time to union, non-union, mal-union, infection, secondary operations, and functional outcomes (AOFAS score). Patients and Methods From August 2020 to August 2021, a prospective randomized study was conducted at the department of orthopedic surgery of Ain-shams University Hospital including 36 patients to compare MIPO vs. ORIF in fixation of extra-articular distal tibial fractures. The patients were allotted to the MIPO or ORIF group with the flip of a coin. Results Regarding complications rate, no cases developed infection in MIPO technique. On the other hand, the ORIF technique had an infection incidence of 16.6% overall, with two cases (11.11 %) developing superficial infection and one case (5.56 %) developing deep infection. There was no significant difference in the incidence of mal-union between both techniques with no cases of non-union in both groups. The MIPO group had only one case of sagittal plane malunion (5.56%), compared with no cases in the ORIF group. There was no significant difference between both groups in secondary operations rate, with one case in each group. Conclusion Both MIPO and ORIF have similar therapeutic efficacy regarding the functional outcome and can be used safely in distal tibial extra-articular fractures. Although MIPO is advantageous over ORIF with earlier weight-bearing, earlier union, and clinical lower incidence of infection, it has delayed operation time.

Strength and clinical test combinations enhance predictions of sagittal and frontal plane biomechanics in single-leg landing

ObjectivesTo determine whether clinical screening tests can predict lower limb joint kinematics and kinetics outcomes eliciting anterior cruciate ligament (ACL) injury risk in single-leg landings. DesignCross-sectional study. SettingLaboratory research. ParticipantsTwenty-six professional male futsal athletes. Main outcome measuresParticipants completed the Modified Star Excursion Balance Test (mSEBT), Lateral Step Down (LSD), Lunge, Hop tests, and isometric strength tests for clinical screening of lower extremity injury risk and performed single-leg landings to assess lower extremity 3D kinematics and kinetics outcomes. ResultsmSEBT, LSD, and isometric strength were the more important tests when constructing the prediction models. The predictive power of clinical tests for screening injury risk significantly increases when combined with strength measurements (p = 0.005, f2 = 0.595). We discerned 11 biomechanical predictions, six explicitly related to the sagittal plane's biomechanics. Some predictions were leg-dependent, with muscle strength tests predominantly predicting biomechanical outcomes of the preferred leg. ConclusionCombining clinical screening tests with strength measures enhances ACL injury risk factors prediction during single-leg landings. Clustering at least two tests improves prediction accuracy, aiding injury prevention planning and decision-making.

The impact of surgical intervention on statographic parameters of patients with diabetic foot syndrome

Taking into account that the prevalence of diabetes mellitus continues to increase worldwide, secondary complications associated with this endocrine disorder are becoming increasingly common. Disruption of glucose homeostasis and hyperglycemia lead to the activation of several pathological metabolic pathways, contributing to the development of vascular insufficiency and neurodegenerative processes in the lower limbs. These processes are the causes of a condition known as diabetic foot syndrome (DFS), which requires special attention and meticulous treatment. Complications in the form of trophic ulcers of the lower limbs are one of the serious consequences of diabetes mellitus (DM) since they often lead to severe medical and social problems, including high rates of limb amputations. The purpose of the research is to investigate the redistribution of plantar pressure depending on the volume of surgical intervention in patients with diabetic foot syndrome (DFS) by measuring individual statographic parameters. The analysis of a series of parameters from statographic studies in patients with diabetic foot syndrome undergoing various volumes of surgical interventions has allowed for a comprehensive understanding of the features of vertical standing of these patients. In the course of the research, it has been revealed that as the support area of the operated foot decreases, there is an increase in body oscillation in both the sagittal and frontal planes relative to the support area. It has been proven that in cases with a normal support area of the foot, the relative body oscillation decreases.

Preliminary Study of Motion Preservation Following Posterior Dynamic Distraction Device in Adolescent Idiopathic Scoliosis Patients.

Motion-sparing scoliosis surgeries such as the posterior dynamic distraction device (PDDD) are slowly increasing in use. However, there is limited clinical data documenting postoperative motion across the PDDD construct. With this cohort study, we aim to measure sagittal and coronal motion following PDDD. We hypothesize coronal and sagittal spinal motion will be partially preserved across the construct. Retrospective review of prospectively collected data. Preoperative and minimum 1-year postoperative coronal range of motion across the instrumented levels was compared. Available flexion/extension radiographs were evaluated postoperatively to assess sagittal arc of motion. Radiographs from latest follow-up were used. At a mean of 1.9 years (1 to 5y), flexibility radiographs were available on 29 patients treated with PDDD (17 thoracic, 12 lumbar). Mean age at surgery was 16 years (12 to 25). Postoperative coronal arc of motion in PDDD patients was 11 degrees (3 to 19 degrees) in the thoracic spine and 10 degrees (0 to 28 degrees) in the lumbar spine. Compared with preoperative motion, the thoracic arc of motion was maintained by 33% (35 to 11 degrees) and lumbar motion was maintained by 30% (34 to 10 degrees). Flexion-extension radiographs were available on 7 patients. Sagittal arc for the upper instrumented vertebral end plate to the lower instrumented vertebral endplate of the cohort was 10 degrees in the thoracic spine (6 to 18) and 14 degrees in the lumbar spine (5 to 21). Sagittal measurements for the changes in the arc of the upper and lower screws on the construct were 4 degrees in the thoracic group (2 to 8) and 9 degrees in the lumbar group (2 to 17). By latest follow-up 11 patients (38%) underwent reoperation, with most cases due to implant breakage (N=4, 14%), extender misalignment (N=2, 7%), and screw misplacement (N=2, 7%). At mean 1.9 years postoperatively, PDDD preserves measurable spinal motion over the construct both in the coronal and the sagittal plane without evidence for autofusion. Coronal arc of motion averages 10 to 12 degrees and sagittal arc of motion ranged from 4 to 14 degrees, although this varies by patient. This study confirms that PDDD for pediatric scoliosis preserves a measurable degree of postoperative flexibility both in the sagittal and coronal planes. Level II-therapeutic study.

Quantitative analysis of sagittal curvatures of the tibial plafond by computed tomography.

Although the talar morphology has been well understood, studies on the corresponding tibial plafond are still lacking. Based on computed tomography (CT) data, this quantitative study divided the tibial plafond into anterior and posterior regions on five sagittal sections. The objectives of this study were (I) to determine whether the sagittal curvatures of the tibial plafond can be quantitatively and accurately described using the double-diameter method; (II) to compare the difference between the anterior and posterior diameters on five sagittal sections. In this study, CT data were collected from 100 adult ankles, and the three-dimensional (3D) ankle joint model was reconstructed using CT images. An anatomical coordinate system of the 3D ankle joint model was created to establish the standard coronal and sagittal planes. The measurement outcomes of sagittal curvatures included: the anterior and posterior diameters, the distal tibial arc length (TiAL) and the distal tibial mortise depth (TMD) on five sagittal sections (the most medial, medial 1/4, middle, lateral 1/4 and the most lateral section). Subgroup analysis was performed to compare the differences between males and females. Analysis of the sagittal curvatures showed that the anterior diameter of tibial plafond was significantly smaller than the posterior diameter on five sagittal sections with a mean difference ranging from 3.9 to 6.8 mm (P<0.001). For the anterior diameters, the anteromedial curve had the smallest diameter (35.3±5.3 mm), and the anterolateral curve had the largest diameter (38.0±5.8 mm). For the posterior diameter, the posteromedial curve had the smallest diameter (39.2±6.4 mm), and the posterolateral 1/4 curve had the largest diameter (43.5±6.9 mm). One-way analysis of variance (ANOVA) revealed significant differences in the anterior and posterior diameters among five groups (P<0.012). Subgroup analysis showed that gender partly affected the results of sagittal curvature measurements. The sagittal curvatures of the tibial plafond can be described quantitatively and accurately using anterior and posterior diameters. Our study showed that there were significant differences between the anterior and posterior diameters, and gender was an important factor influencing the sagittal curvatures of the tibial plafond.

Occlusal Plane changes with mini-implants to solve complex cases

Controlling the occlusal plane in the three dimensions is essential for correcting complex functional imbalances and achieving proper smile aesthetics. Mini-implants have transformed modern orthodontics by providing enhanced anchorage control and improved predictability, thereby enabling novel treatment opportunities. These opportunities include the simultaneous distalization of all teeth in an arch, retraction of the anterior dental segment, non-surgical rapid palatal expansion in adults, correction of the gummy smile through entire maxillary arch intrusion, and modifications to the occlusal plane. The latter involves changes along the x-axis in the coronal plane, specifically addressing asymmetries in the frontal norm, as well as changes along the y-axis in the sagittal plane, which address inclinations of the occlusal plane such as anterior open bites. Additionally, modifications involve changes along the z-axis in the axial plane, correcting inclinations of the occlusal plane, including posterior sagittal discrepancies like Class II and III and midline corrections. This paper focuses on the latest and most accurate techniques, from diagnostic tools to detailed biomechanical execution of several treated clinical cases, with an emphasis on successful three-dimensional management of dental arches and occlusal planes.

In-shoe multi-segment foot kinematics measurement during the stance phase of running using a stretch strain sensor

Multi-segment foot kinematics during shod running are difficult to investigate in clinical settings. Stretch strain sensors can measure foot kinematics; however, whether they can evaluate foot kinematics during shod running or at the midfoot kinematics remains unclear. The aim of this study was to investigate the stretch strain sensor could reveal differences between shod and barefoot conditions and midfoot kinematics during running.Eighteen healthy adults were included in the study. A stretch strain sensor and three-dimensional motion capture system were used to measure foot kinematics during barefoot and shod running with a rearfoot strike pattern. The correlation between the amplitudes of the two signals during barefoot running was investigated, and the similarity between the two signals was evaluated using the cross-correlation coefficient. Statistical parametric mapping was used to compare shod and barefoot conditions.Shod running had significantly lower sensor strain from 30 % to 100 % stance compared to barefoot running (p < 0.05). The sensor amplitude was significantly correlated with the shank–rearfoot frontal (r = 0.668, p = 0.002), the rearfoot–midfoot transverse (r = 0.546, p = 0.02), and the midfoot–forefoot sagittal planes (r = 0.563, p = 0.01). A high cross-correlation was observed between the sensor signal and the shank–rearfoot sagittal, frontal, and transverse planes and the midfoot–forefoot sagittal plane.This sensor can be used to investigate foot kinematics during shod running. The sensor signal mainly reflects the shank–rearfoot frontal and midfoot–forefoot sagittal planes, as well as the maximum kinematic range of the rearfoot-midfoot transverse plane.

ПРОГНОЗНАЯ ОЦЕНКА КОЛЛАПСА СУСТАВНОЙ ПОВЕРХНОСТИ ПРИ СУБХОНДРАЛЬНОМ ПЕРЕЛОМЕ НЕДОСТАТОЧНОСТИ КОСТНОЙ ТКАНИ КОЛЕННОГО СУСТАВА (SIFK)

Background. Subchondral insufficiency fracture of the knee (SIFK) is a frequent cause of knee joint pain in patients over 55 years of age. Diagnosis of this pathology at an early stage has certain difficulties, as it requires magnetic resonance imaging (MRI). Aim of the study. To determine the relationship between the size of the lesion in subchondral insufficiency fracture of the knee joint, the patient's body mass index and the risk of articular surface collapse. Material and Methods. In 35 female patients with subchondral insufficiency fracture the size of the lesion in frontal and sagittal planes, as well as its volume according to MRI were determined. The obtained results made it possible to assess the risk of articular surface collapse. Results. The study revealed a relationship between the size of the lesion and the risk of articular surface collapse in subchondral insufficiency fracture of the knee. An anteroposterior size of the lesion of more than 14.1 mm, a transverse size of more than 10.2 mm, and a craniocaudal size of more than 1.22 mm are risk factors for subsequent articular surface collapse and progression of osteoarthritis of the knee joint. The analysis of the correlation between body mass index (BMI) and the development of articular surface collapse found no specific BMI value associated with articular surface collapse. Conclusions. A risk factor for articular surface collapse in patients with subchondral bone insufficiency fracture of the knee joint was determined, which allows predicting the outcomes of the disease treatment. Body mass index and the development of articular surface collapse do not correlate with each other.

Poster 173: Evaluation of Radius of Curvature of the Humeral Capitellum in Young Athlete Osteochondritis Dissecans Lesion Sites

Objectives: Elbow Osteochondritis dissecans (OCD) lesions are often seen in young baseball players and gymnasts. Prior studies have suggested that capitellar OCD lesions are frequently found in two distinct and separate locations in these two populations: at 58° and 28° inclination angles from the humeral axis in baseball players and gymnasts respectively. As treatment of OCD lesions with osteochondral allografts and autografts have gained popularity, an increased emphasis has been placed on the utilization of measurements of capitellar radius of curvature (ROC) to minimize articular incongruity or ROC mismatch between the recipient elbow and donor knee. The purpose of this study was to further characterize the coronal-axial ROC in these two distinct locations and potentially identify morphological differences between the two OCD lesion locations. Methods: Elbow MRIs of thirty pediatric patients between the ages of eight and seventeen with no history of elbow injuries were retrospectively studied. Using the radiographic diagnostic viewing software, eUnity, two reviewers measured capitellar ROCs encompassing at least a ten-millimeter plug at both 58° and 28° inclination angles from the humeral axis on coronal-axial elbow MRIs for each patient. Coronal-axial views were established by using the 3D function to orient the axial plane in parallel with the capitellar articular surface and the coronal plane perpendicular to the capitellar surface. 58° and 28° inclination angles from the humeral axis were measured in the sagittal plane, and coronal-axial images were transformed in phase with each inclination angle. For each observer, paired two-tail t-tests were performed to evaluate statistical differences in ROC measurements between the two locations. Inter-observer absolute agreement was examined using the “irr” Intraclass Correlation Coefficient R package. Using a Fisher’s test, p values from the individual observer paired t-tests were combined and reviewed. Results: The Intraclass Correlation Coefficients were 0.886 for the 58° inclination angle and 0.921 for the 28° inclination angle, respectively denoting good and excellent inter-observer reliability. Paired two-tailed t-tests of each observer’s 58° and 28° capitellar ROC measurements yielded p&lt;0.001. The unweighted average t-value of 10.49 with 29 degrees of freedom and the combined Fisher p-value of &lt;0.001 suggest there is a significant difference between the ROC measurements at the 58° and 28° humeral capitellar locations. Average ROC measurements ranged between 13.94mm ± 1.31mm and 14.3mm ± 1.42mm at the 58° capitellar location and 11.7mm ± 1.53mm and 11.76mm ± 1.30mm at the 28° capitellar location. Measurements at the 28° inclination angle from the humeral axis tended to be smaller than those of the 58° inclination angle from the humeral axis. On average the ROC at the 28° inclination was between 2.18mm and 2.50mm smaller than the ROC at the 58° inclination. Conclusions: Prior studies have identified differences in capitellar OCD lesion location between baseball players and gymnasts. This study offers further characterization of both morphologic locations. The capitellar radii of curvature at 58° and 28° inclination angles from the humeral axis statistically differed, as demonstrated by both observer measurements. The ROC at the 28° inclination was on average between 2.18mm and 2.50mm smaller than the ROC at the 58° inclination. Therefore, because of evident ROC differences between these two locations, it may be beneficial to consider anatomic morphologic differences between distinct humeral capitellum regions when selecting graft locations to achieve an optimal osteochondral autograft match. Future research on optimizing donor-to-recipient ROC may improve articular congruity restoration and long-term outcomes.

Temporal changes in tibiofemoral relationship following anterior cruciate ligament injury: Implications for rotational dynamics and clinical outcomes.

This study aims to elucidate changes in the tibiofemoral relationship over time following anterior cruciate ligament (ACL) injury, and investigate the correlation between the tibiofemoral relationship and patient-related outcome measures (PROMs). Overall, 203 primary ACL reconstructions were performed using autologous hamstring grafts. Medial and lateral anterior tibial translation (ATT) in the sagittal plane and tibial tubercle-trochlear groove (TT-TG) distance in the axial plane were measured using pre-operative magnetic resonance imaging and post-operative computed tomography. The difference between pre-operative and post-operative values for each parameter was calculated: ΔMesdial ATT, ΔLateral ATT and ΔTT-TG distance. The correlation between each calculated value and the time elapsed since ACL injury, and the correlation between each calculated value and PROMs-evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS)-were assessed. Sixty-four patients were enroled. Medial ATT, lateral ATT and TT-TG distance were significantly different pre-operatively compared to post-operative values, with the tibia translating anteriorly and rotating internally relative to the femur. ΔMedial ATT, ΔLateral ATT and ΔTT-TG distance were 1.6, 8.8 and -4.8 mm, respectively. A negative correlation was observed between the ΔTT-TG distance and the time elapsed since the injury (r = -0.44, p < 0.01). No correlation was found between ΔMedial ATT and the time elapsed since the injury, nor between ΔLateral ATT and the time elapsed since the injury. Neither the ΔMedial ATT, ΔLateral ATT, nor ΔTT-TG distance correlated with the pre-operative or post-operative KOOS subscale scores. The tibia underwent internal rotation relative to the femur over time following ACL injury, highlighting the importance of assessing rotational changes in ACL-injured knees. Level Ⅲ.

Computer-assisted revision total knee arthroplasty does not improve postoperative knee prosthesis alignment compared to the conventional technique.

Computer-assisted surgery (CAS) during primary total knee arthroplasty (TKA) prosthesis alignment. However, literature on its use during revision TKA (rTKA) is scarce. Moreover, the effect of CAS during rTKA on rotational alignment of the prosthesis has not been described yet. The purpose of this study was to assess the effect of CAS during rTKA, focusing on the number of outliers and coronal, sagittaland rotational prosthetic alignment compared to conventional rTKA. A prospective cohort study comparing CAS-rTKA with a historical control group (CON-rTKA). The CAS-rTKA group (54 patients/62 knees) underwent rTKA using imageless CAS between 2012 and 2017. The CON-rTKA group (13 patients/23 knees) was operated using the conventional technique between 2002 and 2012. Postoperative alignment was measured using the EOS-2D/3D system (coronal and sagittal planes) and computed tomographyscan (rotation). No significant differences between the CAS-rTKA and CON-rTKA groups were found for coronal and sagittal alignment regarding the mechanical angle of the leg (p = 0.08), mechanical lateral distal femoral angle (p = 0.87), mechanical medial proximal tibial angle (p = 0.40), anatomical proximal posterior tibial angle (p = 0.43) nor femoral (p = 0.80) and tibial rotation (p = 0.15). For the proportions of coronal, sagittaland rotational outliers, no significant differences were found either. This study showed no evidence that use of CAS during rTKA leads to improved coronal, sagittalor rotational alignment of knee prosthesesor a difference of outliers between the groups. Level III, therapeutic.

Accuracy of patient-specific instrumentation for implant positioning in custom-made total ankle arthroplasty.

This retrospective radiological analysis aimed to assess the accuracy of implant positioning in patients with ankle arthritis undergoing custom-made total ankle arthroplasty (TAA) with patient-specific instrumentation (PSI) compared with preoperative planning. Patients who underwent custom-made TAA with PSI from January 2018 to March 2023 were retrospectively evaluated, focusing on the tibial anterior surface (TAS) angle, tibial lateral surface (TLS) angleand tibiotalar ratio (TTR). Additionally, data regarding the time from the preoperative computed tomography (CT) scan to surgery, associated proceduresand complications were recorded. No associated procedures were performed, and only one intraoperative complication, an iatrogenic lateral malleolar fracture, was recorded. In the coronal plane, custom-made TAA with PSI consistently achieved precise positioning of prosthetic components, even in cases with significant preoperative deformities or bone deficits. However, a statistically significant deviation from the planned values was observed in the sagittal plane (p = 0.007). A notable correlation was identified between the time elapsed from the preoperative CT scan to surgery and the deviation from the planned to the actual postoperative TAS angle (p < 0.001). This study underscores the efficacy of PSI systems in achieving precise positioning in the coronal plane, in accordance with preoperative planning. In contrast, sagittal plane positioning did not demonstrate the same level of accuracy, as evidenced by a statistically significant difference between the planned and postoperative TLS values. Nevertheless, all measurements remained within the recommended range according to the existing literature. Level IV.

Response of Knee Joint Biomechanics to Landing Under Internal and External Focus of Attention in Female Volleyball Players.

The aim of this study was to examine the effect of attentional focus instructions on the biomechanical variables associated with the risk of anterior cruciate ligament injury of the knee joint during a drop landing task using a time series analysis. Ten female volleyball players (age: 20.4 ± 0.8years, height: 169.7 ± 7.1cm, mass: 57.6 ± 3.1kg, experience: 6.3 ± 0.8years) performed landings from a 50cm height under three different attentional focus conditions: (1) external focus (focus on landing as soft as possible), (2) internal focus (focus on bending your knees when you land), and (3) control (no-focus instruction). Statistical parameter mapping in the sagittal plane during the crucial first 30% of landing time showed a significant effect of attentional focus instructions. Despite the similarity in landing performance across foci instructions, adopting an external focus instruction promoted reduced vertical ground reaction force and lower sagittal flexion moment during the first 30% of execution time compared to internal focus, suggesting reduced knee loading. Therefore, adopting an external focus of attention was suggested to reduce most biomechanical risk variables in the sagittal plane associated with anterior cruciate ligament injuries, compared to internal focus and control condition. No significant differences were found in the frontal and horizontal planes between the conditions during this crucial interval.

Spinal cord metrics derived from diffusion MRI: improvement in prognostication in cervical spondylotic myelopathy compared with conventional MRI.

A major shortcoming in optimizing care for patients with cervical spondylotic myelopathy (CSM) is the lack of robust quantitative imaging tools offered by conventional MRI. Advanced MRI modalities, such as diffusion MRI (dMRI), including diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI), may help address this limitation by providing granular evaluations of spinal cord microstructure. Forty-seven patients with CSM underwent comprehensive clinical assessments and dMRI, followed by DTI and DBSI modeling. Conventional MRI metrics included 10 total qualitative and quantitative assessments of spinal cord compression in both the sagittal and axial planes. The dMRI metrics included 12 unique measures including anisotropic tensors, reflecting axonal diffusion, and isotropic tensors, describing extraaxonal diffusion. The primary outcome was the modified Japanese Orthopaedic Association (mJOA) score measured at 2 years postoperatively. Extreme gradient boosting-supervised classification algorithms were used to classify patients into disease groups and to prognosticate surgical outcomes at 2-year follow-up. Forty-seven patients with CSM, including 24 (51%) with a mild mJOA score, 12 (26%) with a moderate mJOA score, and 11 (23%) with a severe mJOA score, as well as 21 control subjects were included. In the classification task, the traditional MRI metrics correctly assigned patients to healthy control versus mild CSM versus moderate/severe CSM cohorts, with an accuracy of 0.647 (95% CI 0.64-0.65). In comparison, the DTI model performed with an accuracy of 0.52 (95% CI 0.51-0.52) and the DBSI model's accuracy was 0.81 (95% CI 0.808-0.814). In the prognostication task, the traditional MRI metrics correctly predicted patients with CSM who improved at 2-year follow-up on the basis of change in mJOA, with an accuracy of 0.58 (95% CI 0.57-0.58). In comparison, the DTI model performed with an accuracy of 0.62 (95% CI 0.61-0.62) and the DBSI model had an accuracy of 0.72 (95% CI 0.718-0.73). Conventional MRI is a powerful tool to assess structural abnormality in CSM but is inherently limited in its ability to characterize spinal cord tissue injury. The results of this study demonstrate that advanced imaging techniques, namely DBSI-derived metrics from dMRI, provide granular assessments of spinal cord microstructure that can offer better diagnostic and prognostic utility.

Distal forelimb radiographic bone morphology in Thoroughbred foals during the first 10 months post-partum. Part 1: Carpus.

The risk of carpal injury in racehorses may be related to the morphology, yet whether carpal morphologies are set from birth or change through growth remains unclear. To quantify carpal bone changes through growth. Twenty privately owned Thoroughbred foals born between January 2022 and May 2023 were radiographed bimonthly from birth to 10 months of age. Imprint training was used to take radiographs safely without chemical restraints. Fifteen individual and 11 relative angular carpal parameters were measured using ImageJ on dorsopalmar radiographs of the carpus at zero degrees of vertical and horizontal rotation. Associations with age (growth), sex and the differences between left and right limbs were analysed separately using a linear mixed effects model. Six individual carpal parameters changed with age (radial carpal joint [RCJ], Prx.dor. radial carpal [Cr], Prx.Cu, Dis.dor. third carpal [C3], Dis.pal.C3 and Dis.pal. intermediate carpal), and one was influenced by side, that is higher in the left carpus (Dis.pal.Cr). Seven relative parameters changed with age, and one relative parameter was influenced by side, that is higher in the left (Ra.met-RCJ). The proximo-dorsal bone surface angle of Cr and disto-dorsal bone surface angle of C3 became flatter over time, which may be associated with the re-direction of the load towards the sagittal carpal plane. Sex did not influence any of the carpal parameters, nor did the combined effect of age, side of the limb and sex. Specific individual and relative angular carpal parameters changed significantly over time and some differed between the left and right limb, whereas other parameters did not change. The steeper carpal bone angles achieved proximally with the parameters that did change may improve stability by redirecting the load more medially through the carpus and the proximal and distal bones.

Poster 369: Medial and Lateral Posterior Tibial Slope in the Skeletally Immature: A Cadaveric Study

Objectives: Increased knee posterior tibial slope (PTS) angle is risk factor for primary and secondary ACL injury. Adult biomechanical research indicates that decreasing the PTS may reduce ACL injuries, and osteotomy techniques have been developed to alter tibia slope to reduce risk of re-injury. Pediatric and adolescent athletes have the highest rates of primary and secondary ACL injury, and many in this age group may have abnormal PTS angle. The purpose of this study was to evaluate PTS in medial and lateral tibial plateaus in large database of CT scans, and to develop normative PTS data in this age group. Methods: IRB approval was waived, as the specimens were donated for research, no genetic information was collected, and there were no plans for family contact. 83 pediatric knee CT scans, ranging from ages 1 to 12, were analyzed using OsiriX imaging software. The PTS was evaluated at two distinct points on sagittal CT sections: (1) At the medial tibia plateau and 2) lateral tibial plateau, both aligned with the central part of on a coronal view of the medial femoral and lateral femoral condyles respectively condyle. Results: The average medial PTS angle was 6.56° ± 3.84° and 6.81° ± 3.62° for the lateral PTS. There was not a significant statistical difference between the medial and lateral PTS (P = 0.6632, determined using an independent-samples t-test and analysis of variance). When plotting the age versus PTS, we observed a positive correlation with the medial PTS (R2 = 0.0385) and a negative correlation with the lateral PTS (R2 = 0.0393). Conclusions: The data demonstrate variability in medial and lateral pediatric PTS and provides normative values for pediatric PTS values. For pediatric patients undergoing ACL surgeries, consideration of increased PTS values that are associated with higher rates of recurrent ACL injury may influence surgical treatment techniques. Correction of increased PTS to lower ACL injury risk is performed in adults with major corrective osteotomy surgery, but such procedures have not been performed in children due to osteotomy-induced damage to growth plates. Due to open growth plates, pediatric patients may be treated with minimally invasive guide growth procedures to lower PTS, with minimal complication risk. Guided growth procedures have a long history of successful alignment correction in the coronal plane. Future animal and clinic studies may also demonstrate the safety and effectiveness of guided growth sagittal plane correction as applied to increased PTS. PTS developmental anatomy and its relationship to ACL injury is crucial for surgical advancements, including the use of low risk guided growth interventions to reduce PTS and ACL injury in pediatric patients with high risk of recurrent injury.

Center of Pressure Velocity and Dynamic Postural Control Strategies Vary During Y-Balance and Star Excursion Balance Testing.

Dynamic postural control (DPC) describes an individual's ability to maintain balance within their base of support in both anticipatory and reactive balance situations and has been measured using center of pressure (COP) velocity. Common standardized DPC assessments for active adults include the modified Star Excursion Balance Test (MSEBT) and the Y-Balance Test (YBT). The purpose of this study was to explore DPC during performance of the MSEBT, the YBT, and a modified version of the YBT, the MYBT. It was hypothesized that feedback from the YBT/MYBT reach indicator would enhance DPC. Cross-sectional study. Twenty-one participants (9 females, 12 males, mean age 24.5±1.2 years) performed three trials in each direction (anterior-AN, posteromedial-PM, and posterolateral-PL) on each balance test during one session. The YBT frame was placed atop a force plate for all testing. Frontal and sagittal plane COP velocities (COPx and COPy, respectively) were recorded throughout each trial and resultant COP (COPr) velocities were calculated. Significant main effects were present for test (F=4.485, p\<0.001) and reach direction (F=61.594, p\<0.001). Post hoc analyses for test indicated significant differences in COPy between YBT and MSEBT (p=0.034) and between MYBT and MSEBT (p\<0.001), as well as significant differences in COPr between MYBT and MSEBT (p=0.002). Post hoc analyses for reach direction revealed significant differences in COPx between AN and both PM (p\<0.001) and PL (p\<0.001) directions, in COPy between AN and PM (p\<0.001) and PL (p\<0.001) directions, and COPr between AN and PL (p=0.043) directions only. External proprioceptive feedback from the reach indicator improved DPC during the YBT and MYBT when compared to the MSEBT. Sagittal plane COP velocities were reduced when external proprioceptive feedback from the reach indicator was present, while frontal plane COP velocities were not affected in this group of participants. 2b.