J arch: A contemporary soft-tissue landmark for anatomic placement of femoral tunnel in remnant-preserving anterior cruciate ligament (ACL) reconstruction

Objectives: Femoral tunnel placement is a critical step in ACL reconstruction surgery. Surgeons usually end up clearing the soft tissue to access the bony landmarks. Biological ACL reconstruction with preservation of soft tissue can be done with reliable soft tissue landmarks. Our objective is to assess the reliability of a soft tissue landmark- femoral ACL remnant, for appropriate femoral tunnel placement in soft tissue preserving ACL reconstruction. Materials and Methods: This study was a retrospective analysis of prospectively collected data of 40 consecutive patients who underwent primary ACL reconstruction in January 2018 by a single surgeon. An inverse J shaped tissue arch was identified and used as soft tissue landmark for anatomic placement of femoral tunnel. This arch was a part of femoral ACL remnant. MRI films were examined post-operatively to determine the position of the femoral tunnel. Postoperatively, MRI of these patients were reviewed to evaluate the femoral tunnel position in terms of depth and height from the proximal condylar surface and notch roof, respectively. Results: The center of the femoral tunnel was found to be at a mean depth of 27.12 ± 2.2% from the proximal condylar surface (parallel to Blumensaat’s line) and a mean height of 30.96 ± 2.75% from the notch roof (perpendicular to Blumensaat’s line), which is at par with previously defined data given by various studies. Conclusion: J arch can be used as a dependable soft tissue landmark and a guide for the anatomic placement of femoral tunnel in biological ACL Reconstruction.

Anterior Skull Base Analysis from Coronal and Reconstructed Computed Tomography: Radio-Anatomical Study

Endoscopic sinus and skull base Surgery has gained significant improvement widely all over the world. A computerized tomography (CT) scan provides a detailed anatomy of the skull base especially the bone framework. This study aims to analyze the fixed anatomical bony landmarks of the anterior skull base through coronal and reconstructed CT in the context of the Nepalese population and guide the surgeon to perform endoscopic sinus and skull base surgery safely. This Prospective study includes 70 Computerized Tomography scans of Paranasal sinuses. The different measurement from nasal floor to skull base was taken in coronal and reformatted sagittal CT scan. Mean, standard deviation, minimum and maximum values were analyzed using descriptive statistics. Student T-test was applied to compare between right and left side. This study includes 75 patients between 18 to 77 years. The measurement from nasal floor to the cribriform plate and ethmoidal roof in right and left side were, mean± SD (47± 4.1, 45.3±4.3, 47.9±5.1, and 49±8.5 mm) respectively. Mean Take off angle at the cribriform plate was 43.9 ±10.9°on right side and 43 ± 9.4° on the left side. The distance from the nasal spine to the skull base (mean ± SD) at nasofrontal recess, bulla ethmoidalis, and the junction of sphenoethmoid levels at right sides were 51.5 ± 4.7, 52.9 ± 4.1, and 61.2 ±4.7 little higher at left side. This study provides a detailed analysis of the anterior skull base in coronal and sagittal CT scans which helps to reduces complications.

Assessment of Stability of MIMU Probes to Skin-Marker-Based Anatomical Reference Frames During Locomotion Tasks: Effect of Different Locations on the Lower Limb

Soft tissue artefacts (STAs) undermine the validity of skin-mounted approaches to measure skeletal kinematics. Magneto-inertial measurement units (MIMU) gained popularity due to their low cost and ease of use. Although the reliability of different protocols for marker-based joint kinematics estimation has been widely reported, there are still no indications on where to place MIMU to minimize STA. This study aims to find the most stable positions for MIMU placement, among four positions on the thigh, four on the shank, and three on the foot. Stability was investigated by measuring MIMU movements against an anatomical reference frame, defined according to a standard marker-based approach. To this aim, markers were attached both on the case of each MIMU (technical frame) and on bony landmarks (anatomical frame). For each MIMU, the nine angles between each versor of the technical frame with each versor of the corresponding anatomical frame were computed. The maximum standard deviation of these angles was assumed as the instability index of MIMU-body coupling. Six healthy subjects were asked to perform barefoot gait, step negotiation, and sit-to-stand. Results showed that (1) in the thigh, the frontal position was the most stable in all tasks, especially in gait; (2) in the shank, the proximal position is the least stable, (3) lateral or medial calcaneus and foot dorsum positions showed equivalent stability performances. Further studies should be done before generalizing these conclusions to different motor tasks and MIMU-body fixation methods. The above results are of interest for both MIMU-based gait analysis and rehabilitation approaches using wearable sensors-based biofeedback.

Anatomic Rotational Relationship of Distal Femur in Indian Population and its Implication in Total Knee Arthroplasty: A Magnetic Resonance Imaging Based Study

Background Bony landmarks for referencing distal femoral rotation may differ with ethnic populations. The study aims to find out the relationship of the bony landmarks of distal femur for rotational alignment of femoral component in total knee arthroplasty in Indian population and compare it with other ethnic groups. Methods Rotational relationship of distal femoral bony landmarks was studied using magnetic resonance images of 141 knees. The condylar twist angle (CTA), Whiteside's-posterior condylar axis angle (WL/PCL), Whiteside's-anatomical epicondylar angle (WL/A-EA) and difference between the two epicondylar axes (S-EA/A-EA) were measured. The effect of gender, side and age of these relationships was analyzed. Results The mean CTA, WL/A-EA/WL/PCL and A-EA/S-EA was found to be 5.59 ± 2°, 89.38 ± 2.66°, 5.44 ± 2.88°, 3.11 ± 0.54° respectively. A-EA/S-EA was found to be lower in younger population as compared to the older population. Rest none of the variables showed any significant difference when compared against age, sex or side. Conclusion The posterior condylar axis was 5.59˚ externally rotated in relation to clinical epicondylar axis. About 2.5° of added external rotation is required in jigs using the conventional 3° of inbuilt external rotation, if clinical epicondylar axis is taken as reference for apt placement of the femoral component.

The Course and Anatomical Characteristics of Sciatic and Femoral Nerves in Unilateral Crowe Type IV Hip Dysplasia

Background This study aims to investigate the course and anatomical characteristics of sciatic and femoral nerves in unilateral Crowe type IV developmental dysplasia of the hip (DDH) patients. Methods We conducted a retrospective own-control study of patients with unilateral Crowe type IV DDH. Bilateral hips’ CTs of 21 female patients were reviewed in our institute from February 2018 to February 2020. The distances between nerves and bony landmarks were measured in different CT sections (anterior superior iliac spine, acetabular inner wall, teardrop, and ischial tuberosity) to analyze the anatomical position and course of sciatic and femoral nerves between bilateral hips. Results In the section of acetabular inner wall, the distance between femoral nerve and acetabular anterior wall in affected hip (13.20±3.59 mm) was significantly smaller than that in healthy hip (16.58±5.12mm) (p=0.000). In other sections, the distances between nerves and bony landmarks in affected hips were significantly larger than or equal to those in healthy hips. Conclusion In female patients with unilateral Crowe type IV DDH, the femoral nerve in affected hip runs closer to anterior acetabular wall than that in healthy hip.

Evaluating for a correlation between osteopathic examination and ultrasonography on thoracic spine asymmetry

Context The thoracic spine is a common area of focus in osteopathic manipulative medicine (OMM) for a variety of conditions. Thoracic spine somatic dysfunction diagnosis is achieved by palpating for asymmetry at the tips of the transverse processes (TPs). Previous studies reveal that instead of following the rule of threes, the TPs of a given thoracic vertebra generally align with the spinous process (SP) of the vertebra above. Ultrasonography has been widely utilized as a diagnostic tool to monitor musculoskeletal conditions; it does not utilize ionizing radiation, and it has comparable results to gold-standard modalities. In the case of thoracic somatic dysfunction, ultrasound (US) can be utilized to determine the location of each vertebral TP and its relationship with the SP. Previous studies have investigated the correlation between OMM and ultrasonography of the cervical, lumbar, and sacral regions. However, there has been no study yet that has compared osteopathic structural examination with ultrasonographic examination of the thoracic vertebral region. Objectives To examine the relationship between osteopathic palpation and ultrasonographic measurements of the thoracic spine by creating a study design that utilizes interexaminer agreement and correlation. Methods The ClinicalTrials.gov study identifier is NCT04823637. Subjects were student volunteers recruited from the Midwestern University (MWU)—Glendale campus. A nontoxic, nonpermanent marker was utilized to mark bony landmarks on the skin. Two neuromusculoskeletal board-certified physicians (OMM1, OMM2) separately performed structural exams by palpating T2–T5 TPs to determine vertebral rotation. Two sonographers (US1, US2) separately scanned and measured the distance from the tip of the SP to the adjacent TPs of the vertebral segment below. Demographic variables were summarized with mean and standard deviation. Interexaminer agreement was assessed with percent agreement, Cohen’s Kappa, and Fleiss’ Kappa. Correlation was measured by Spearman’s rank correlation coefficient. Recruitment and protocols were approved by the MWU Institutional Review Board (IRB). Results US had fair interexaminer agreement for the overall most prominent segmental rotation of the T3–T5 thoracic spine, with Cohen’s Kappa at 0.27 (0.09, 0.45), and a total agreement percentage at 51.5%. Osteopathic palpation revealed low interexaminer agreement for the overall most prominent vertebral rotation, with Cohen’s Kappa at 0.05 (0.0, 0.27), and 31.8%. Segment-specific vertebral analysis revealed slight agreement between US examiners, with a correlation coefficient of 0.23, whereas all other pairwise comparisons showed low agreement and correlation. At T4, US had slight interexaminer agreement with 0.24 correlation coefficient, and osteopathic palpation showed low interexaminer (OMM1 vs. OMM2) agreement (0.17 correlation coefficient). At T5, there was moderate agreement between the two sonographers with 0.44 (0.27, 0.60) and 63.6%, with a correlation coefficient of 0.57, and slight agreement between OMM1 and OMM2 with 0.12 (0.0, 0.28) and 42.4%, with 0.23 correlation coefficient. Conclusions This preliminary study of an asymptomatic population revealed that there is a low-to-moderate interexaminer reliability between sonographers, low-to-slight interexaminer reliability between osteopathic physicians, and low interexaminer reliability between OMM palpatory examination and ultrasonographic evaluation of the thoracic spine.

A Validation of Supervised Deep Learning for Gait Analysis in the Cat

Gait analysis in cats and other animals is generally performed with custom-made or commercially developed software to track reflective markers placed on bony landmarks. This often involves costly motion tracking systems. However, deep learning, and in particular DeepLabCutTM (DLC), allows motion tracking without requiring placing reflective markers or an expensive system. The purpose of this study was to validate the accuracy of DLC for gait analysis in the adult cat by comparing results obtained with DLC and a custom-made software (Expresso) that has been used in several cat studies. Four intact adult cats performed tied-belt (both belts at same speed) and split-belt (belts operating at different speeds) locomotion at different speeds and left-right speed differences on a split-belt treadmill. We calculated several kinematic variables, such as step/stride lengths and joint angles from the estimates made by the two software and assessed the agreement between the two measurements using intraclass correlation coefficient or Lin’s concordance correlation coefficient as well as Pearson’s correlation coefficients. The results showed that DLC is at least as precise as Expresso with good to excellent agreement for all variables. Indeed, all 12 variables showed an agreement above 0.75, considered good, while nine showed an agreement above 0.9, considered excellent. Therefore, deep learning, specifically DLC, is valid for measuring kinematic variables during locomotion in cats, without requiring reflective markers and using a relatively low-cost system.

Increased Upper Arm Length and Loading Rate Identified as Potential Risk Factors for Injury in Youth Baseball Pitchers

Background: In the throwing elbow, increased elbow torque has been correlated with increased injury risk. Additional insight into the relationships between anthropometric factors and elbow joint loading is warranted. Purpose: To investigate the relationship among physical limb length characteristics, elbow kinetics, and elbow kinematics in youth baseball pitchers and to examine the relationship between elbow varus loading rate and elbow kinetics. Design: Descriptive laboratory study. Methods: A total of 27 male youth baseball pitchers participated (mean ± SD: age, 15.8 ± 2.7 years; height, 176.3 ± 13.0 cm; weight, 71.7 ± 16.4 kg). Upper arm (UA) and forearm (FA) lengths were measured using a moveable sensor to digitize bony landmarks. Kinematic data were collected at 240 Hz using an electromagnetic tracking system. Participants threw 3 fastballs to a catcher at a regulation distance (60 ft 6 in), and the fastest velocity trial was used for analysis. Linear regression was used to determine the relationship among limb length characteristics, elbow kinetics, and elbow kinematics after accounting for the effects of body weight and height. Results: Pitchers with longer UA length experienced increased maximum elbow varus torque ( P = .005) and maximum net elbow force ( P = .001). Pitchers with an increased forearm to UA ratio had decreased elbow compression force ( P < .001) and exhibited a more flexed elbow at foot contact ( P = .001). Pitchers with greater maximum loading rates experienced greater elbow varus torque ( P = .002). Conclusion: In youth baseball pitchers, longer UA length and greater loading rate increase varus torque about the elbow during a fastball pitch. Clinical Relevance: Longer UA length and greater loading rate may place pitchers at risk of injury because of their relationship with kinetic values.

A Functional Radiological and Soft Tissue Classification to Predict Outcomes in Orbital Fracture Surgery in a Multidisciplinary “Real-World” Setting

Purpose: The decision for open reduction and internal fixation (ORIF) of orbital fractures is usually based on clinical severity and soft tissue and bony findings. This study aimed to identify prognostic factors for a successful surgical outcome.Materials and Methods: We included all orbital fractures treated by ORIF referred to the Ophthalmology clinic for assessment over a 12-year period. A successful outcome was defined as (i) a single operation, (ii) improved diplopia and globe position at 6 months, (iii) no surgical complications, and (iv) patient satisfaction. Data was collected on presenting symptoms, orthoptic measurements, time interval from injury to surgery, fracture geometry and involvement of internal, and external bony landmarks. Univariate and multivariate regression was used to identify predictive factors for success.Results: There were 143 cases with median age 35.4 years and 81.8% (117/143) male. 51% (73/143) were complex fractures involving multiple orbital walls. 63.6% (91/143) achieved significant improvement in both enophthalmos and diplopia at 6 months. 15.3% (22/143) had significant preoperative soft tissue or neurogenic injury. 11.8% (17/143) required orbital plate repositioning or removal. 1.4% (2/143) developed orbital haematoma and 4.2% (6/143) had cicatricial entropion. Pre-operative nerve or muscle damage (OR 0.05, p = 0.01) and infraorbital fissure fracture (OR 0.38, p = 0.04) were associated with poor outcomes, whereas an intact posterior ledge was associated with successful outcomes (OR 3.03, p = 0.02).Conclusion: Careful ocular motility evaluation to ascertain neurogenic injury and muscle compartment syndrome, and radiological analysis of the integrity of the posterior ledge and the inferior orbital fissure can facilitate management and expectations of ORIF surgery.