Multimodal sensorimotor assessment of hand and forearm asymmetries: a reliability and correlational study.

Background: Effective rehabilitation of upper limb musculoskeletal disorders requires multimodal assessment to guide clinicians' decision-making. Furthermore, a comprehensive assessment must include reliable tests. Nevertheless, the interrelationship among various upper limb tests remains unclear. This study aimed to evaluate the reliability of easily applicable upper extremity assessments, including absolute values and asymmetries of muscle mechanical properties, pressure pain threshold, active range of motion, maximal isometric strength, and manual dexterity. A secondary aim was to explore correlations between different assessment procedures to determine their interrelationship. Methods: Thirty healthy subjects participated in two experimental sessions with 1 week between sessions. Measurements involved using a digital myotonometer, algometer, inclinometer, dynamometer, and the Nine-Hole Peg test. Intraclass correlation coefficients, standard error of the mean, and minimum detectable change were calculated as reliability indicators. Pearson's correlation was used to assess the interrelationship between tests. Results: For the absolute values of the dominant and nondominant sides, reliability was 'good' to 'excellent' for muscle mechanical properties, pressure pain thresholds, active range of motion, maximal isometric strength, and manual dexterity. Similarly, the reliability for asymmetries ranged from 'moderate' to 'excellent' across the same parameters. Faster performance in the second session was consistently found for the Nine-Hole Peg test. No systematic inter-session errors were identified for the values of the asymmetries. No significant correlations were found between tests, indicating test independence. Conclusion: These findings indicate that the sensorimotor battery of tests is reliable, while monitoring asymmetry changes may offer a more conservative approach to effectively tracking recovery of upper extremity injuries.

Sensor-Based Quantitative Assessment of Children's Fine Motor Competence: An Instrumented Version of the Placing Bricks Test.

The assessment of fine motor competence plays a pivotal role in neuropsychological examinations for the identification of developmental deficits. Several tests have been proposed for the characterization of fine motor competence, with evaluation metrics primarily based on qualitative observation, limiting quantitative assessment to measures such as test durations. The Placing Bricks (PB) test evaluates fine motor competence across the lifespan, relying on the measurement of time to completion. The present study aims at instrumenting the PB test using wearable inertial sensors to complement PB standard assessment with reliable and objective process-oriented measures of performance. Fifty-four primary school children (27 6-year-olds and 27 7-year-olds) performed the PB according to standard protocol with their dominant and non-dominant hands, while wearing two tri-axial inertial sensors, one per wrist. An ad hoc algorithm based on the analysis of forearm angular velocity data was developed to automatically identify task events, and to quantify phases and their variability. The algorithm performance was tested against video recordings in data from five children. Cycle and Placing durations showed a strong agreement between IMU- and Video-derived measurements, with a mean difference <0.1 s, 95% confidence intervals <50% median phase duration, and very high positive correlation (ρ > 0.9). Analyzing the whole population, significant differences were found for age, as follows: six-year-olds exhibited longer cycle durations and higher variability, indicating a stage of development and potential differences in hand dominance; seven-year-olds demonstrated quicker and less variable performance, aligning with the expected maturation and the refined motor control associated with dominant hand training during the first year of school. The proposed sensor-based approach allowed the quantitative assessment of fine motor competence in children, providing a portable and rapid tool for monitoring developmental progress.

Assessment of Variability in Free Flap Color Match to Facial Skin by Donor Site and Race.

OBJECTIVES: To use portable colorimetry to quantify color differences between facial skin and potential three head and neck microvascular free tissue transfer (MFTT) donor sites-radial forearm (RF), anterolateral thigh (ALT), and fibula (FF)-and compare these differences by pigmentation of the donor site skin and self-identified race. METHODS: In this cross-sectional cohort study, healthy volunteers consented to handheld colorimeter measurements at the three potential MFTT donor sites (RF, ALT, FF) to quantify color match to the facial skin using the CIE color space (DeltaE). The comparison of ipsilateral to contralateral cheek served as control for measurements. Cross-sectional measurements in healthy volunteers were then compared to measurements obtained in postoperative head and neck MFTT patients. RESULTS: DeltaE measurements were obtained for 128 healthy controls and 24 postoperative patients (N = 152). With increasing lightness (decreased pigmentation) of the skin at the donor site, the color match significantly worsened (higher DeltaE) across all potential MFTT donor sites (all p < 0.05). DeltaE from healthy controls closely approximated postoperative color match measurements in patients who underwent cervicofacial MFTT (DeltaE RF: 5.3 vs. 6.0, p = 0.432; DeltaE ALT: 6.2 vs. 6.4, p = 0.822; DeltaE FF: 6.0 vs. 6.4, p = 0.806). CONCLUSION: Patients with decreased skin pigmentation who are undergoing head and neck MFTT may experience worse color discrepancy between cervicofacial skin and the transferred skin paddle than those with more pigmented skin. Portable colorimetry may identify patients who could benefit from interventions such as dermis-resected free tissue reconstruction with skin grafting to improve postoperative appearance. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:3581-3586, 2024.

Flexed elbow, abducted shoulder, forearm supinated (FABS) reconstruction from three-dimensional elbow MRI: diagnostic performance assessment in biceps head anatomy and pathology.

AIM: To determine inter-reader analysis and diagnostic performance on digitally reconstructed virtual flexed, abducted, supinated (FABS) imaging from three-dimensional (3D) isotropic elbow magnetic resonance imaging (MRI). MATERIALS AND METHODS: Six musculoskeletal radiologists independently evaluated elbow MRI images with virtual FABS reconstructions, blinded to clinical findings and final diagnoses. Each radiologist recorded a binary result as to whether the tendon was intact and if both heads were visible, along with a categorical value to the type of tear and extent of retraction in centimetres where applicable. Kappa and interclass correlation (ICC) were reported with 95% confidence intervals. Areas under the receiver operating curve (AUC) were reported. RESULTS: FABS reconstructions were obtained successfully in all 48 cases. With respect to tendon intactness, visibility of both heads, and type of tear, the Kappa values were 0.66 (0.53-0.78), 0.24 (0.12-0.37), and 0.55 (0.43-0.66), respectively. For the extent of retraction, the ICC was 0.85 (0.79-0.91) when including the tendons with and without retraction and 0.78 (0.61-0.91) when only including tendons with retraction. For tear versus no tear, AUC values were 0.82 (0.74-0.89) to 0.96 (0.91-1.01). CONCLUSION: Digital reconstruction of FABS positioning is feasible and allows good assessment of individual tendon head tears and retraction with high diagnostic performance.

Assessment of forearm muscles with ultrasound shear wave elastography in patients with acromegaly.

PURPOSE: The effects of acromegaly on soft tissues, bones and joints are well-documented, but information on its effects on muscle mass and quality remains limited. The primary goal of this study is to assess the sonoelastographic features of forearm muscles in patients with acromegaly. METHOD: Forty-five patients with acromegaly and 45 healthy controls similar in terms of gender, age, and body mass index (BMI) were included in a single-center, multidisciplinary, cross-sectional study. The body composition was analyzed using bioelectrical impedance analysis (BIA), and height-adjusted appendicular skeletal muscle index (hSMI) was calculated. The dominant hand's grip strength was also measured. Two radiologists specialized in the musculoskeletal system employed ultrasound shear wave elastography (SWE) to assess the thickness and stiffness of brachioradialis and biceps brachii muscles. RESULTS: The acromegaly group had significantly higher thickness of both the biceps brachii (p = 0.034) and brachioradialis muscle (p = 0.046) than the control group. However, the stiffness of the biceps brachii (p = 0.001) and brachioradialis muscle (p = 0.001) was lower in the acromegaly group than in the control group. Disease activity has not caused a significant difference in muscle thickness and stiffness in the acromegaly group (p > 0.05). The acromegaly group had a higher hSMI (p = 0.004) than the control group. The hand grip strength was similar between the acromegaly and control group (p = 0.594). CONCLUSION: The patients with acromegaly have an increased muscle thickness but decreased muscle stiffness in the forearm muscles responsible for elbow flexion. Acromegaly can lead to a permanent deterioration of the muscular structure regardless of the disease activity.

Efficient Photoacoustic Image Synthesis with Deep Learning.

Photoacoustic imaging potentially allows for the real-time visualization of functional human tissue parameters such as oxygenation but is subject to a challenging underlying quantification problem. While in silico studies have revealed the great potential of deep learning (DL) methodology in solving this problem, the inherent lack of an efficient gold standard method for model training and validation remains a grand challenge. This work investigates whether DL can be leveraged to accurately and efficiently simulate photon propagation in biological tissue, enabling photoacoustic image synthesis. Our approach is based on estimating the initial pressure distribution of the photoacoustic waves from the underlying optical properties using a back-propagatable neural network trained on synthetic data. In proof-of-concept studies, we validated the performance of two complementary neural network architectures, namely a conventional U-Net-like model and a Fourier Neural Operator (FNO) network. Our in silico validation on multispectral human forearm images shows that DL methods can speed up image generation by a factor of 100 when compared to Monte Carlo simulations with 5×108 photons. While the FNO is slightly more accurate than the U-Net, when compared to Monte Carlo simulations performed with a reduced number of photons (5×106), both neural network architectures achieve equivalent accuracy. In contrast to Monte Carlo simulations, the proposed DL models can be used as inherently differentiable surrogate models in the photoacoustic image synthesis pipeline, allowing for back-propagation of the synthesis error and gradient-based optimization over the entire pipeline. Due to their efficiency, they have the potential to enable large-scale training data generation that can expedite the clinical application of photoacoustic imaging.

Non-invasive assessment of muscle compartment elasticity by pressure-related ultrasound in pediatric trauma: a prospective clinical study in 25 cases of forearm shaft fractures.

BACKGROUND: Soft-tissue swelling after limb fractures in pediatric patients is well known to be a risk factor for developing acute compartment syndrome (ACS). Clinical assessment alone is uncertain in specific cases. Recently, we proposed a non-invasive ultrasound-based method to objectify muscle compartment elasticity for monitoring. We hypothesize a strong correlation between the soft-tissue swelling after stabilization of upper limb fractures and the compartment elasticity objectified with a novel ultrasound-based approach in pediatric trauma. PATIENTS AND METHODS: In a prospective clinical study, children suffering forearm fractures but not developing an ACS were included. The muscle compartment elasticity of the m. flexor carpi ulnaris was assessed after surgical intervention by a non-invasive, ultrasound-based method resulting in a relative elasticity (RE in %) in both the control (healthy limb) and study group (fractured limb). Soft-tissue swelling was categorized in four different levels (0-3) and correlated with the resulting RE (%). RESULTS: The RE in the study group (15.67%, SD ± 3.06) showed a significantly decreased level (p < 0.001) compared with the control (22.77%, SD ± 5.4). The categorized grade of soft-tissue swelling resulted in a moderate correlation with the RE (rs = 0.474). CONCLUSIONS: The presented study appears to represent a novel approach to assess the posttraumatic pressure changes in a muscle compartment after fracture stabilization non-invasively. In this first clinical study in pediatric cases, our measurement method represents a low-cost, easy, and secure approach that has the potential to substitute invasive measurement of suspected ACS in muscle compartment conditions. Further investigations in lager cohorts are required to prove its daily clinical practicability and to confirm the expected reliability.

Clinical assessment of absence of palmaris longus muscle and its association with ethnicity.

OBJECTIVE: To compare two clinical tests used for assessment of absence of palmaris longus, and to determine the prevalence of the absence of palmaris longus among ethnic groups in a cosmopolitan setting. Methods: The cross-sectional descriptive study was conducted at the Bahria University Health Sciences, Karachi, from April 2021 to May 2022, during which forearms belonging to Sindhi, Punjabi and Urdu-speaking ethnic groups were tested. Assessment of presence or absence of palmaris longus was performed using Schaeffer's and Thompson's tests. Agenesis and association of ethnicity and agenesis were compared. Data was analysed using SPSS 23. RESULTS: Of the 250 subjects, 152(60.8%) were females and 98(39.2%) were males. The overall mean age was 20.4±2.23 years (range: 18-23 years). In terms of ethnicity, 100(40%) subjects each were Punjabis and Urdu-speaking, while 50(20%) were Sindhis. The total forearms assessed were 500. The overall agenesis was 186(37.2%). When the two assessment tests were compared, highly significant differences were noted (p<0.000). Overall agenesis was highest among Sindhis 40%, followed by 38% in Punjabis, and 35% in Urdu-speaking. Significant differences were observed when one-sided palmaris longus absence was compared with two-sided absence (p<0.037). Conclusion: Schaeffer's test had more accuracy compared to the Thompson's test in the determination of palmaris longus agenesis. There were variations in terms of agenesis among the ethnic groups.

In vivo evaluation of skin of children with LC-OCT: An objective assessment.

BACKGROUND: Several non-invasive skin imaging methods have been developed in recent years. Line-field confocal optical coherence tomography (LC-OCT) is one of them, leading to the best compromise in terms of resolution and penetration depth. Skin biopsies are an essential technique in paediatric dermatology, but they are a major stressful event for the child and their parents. Current LC-OCT studies have not been dedicated to a paediatric population. If, however, LC-OCT proves to be helpful in children, it may help guide and decrease a certain number of skin biopsies. OBJECTIVES: (1) To evaluate the feasibility of using LC-OCT in paediatric patients, and (2) to assess the maturation of skin structures in children over time with this method. METHODS: In vivo LC-OCT images were collected on six specific body regions (forehead, forearm, chest, back, dorsum of the hand and palmar surface) and in six age groups (between the ages of 0 and 16 years). RESULTS: In all body areas and age groups assessed, 9 of 10 images were rated as good-to-excellent, the only exception were the images acquired on the palmar surface. LC-OCT allowed visualizing very well the skin structures up to a penetration of 500 µm. We observed that the body regions located on the upper extremities of the body (forearm, dorsum of the hand and palmar surface) showed both a maturation on their structure and differences in thickness with respect to the other regions evaluated. CONCLUSIONS: LC-OCT can easily be used for non-invasive imaging of children's skin and allows to document progressive skin changes in the different age groups. It may be a useful asset for imaging and diagnosing superficial skin disorders and as such reducing the number of invasive procedures while increasing the speed of diagnosis in the paediatric population.

The assessment of natural human skin tension orientation and its variation according to age for two body areas: Forearm and thigh.

Human skin has a complex multilayer structure consisting of non-homogeneous, non-linear, viscoelastic and anisotropic materials subjected to in vivo natural pre-tension. This natural tension stems from networks of collagen and elastin fibers. The 3D organization of the collagen and elastin fibers underpins the multidirectional natural tensions in the skin volume while the state of the networks formed influences the surface topography of the skin. This topography depends on the area of the body and on the age of the person. Experiments reported in the literature have been performed ex vivo or on cadavers. By contrast, this work proposes the characterization of the anisotropic natural tension of the human skin in vivo. Experimental tests were performed on the forearms and thighs of 42 female volunteers representing two age groups [20 - 30] and [45-55] years old. Non-contact impact tests and skin-folding tests were conducted using devices developed at the LTDS (Lyon, France). The impact test generated a Rayleigh wave that spread in the skin. The speed of this wave was measured in 7 directions to study the anisotropy of the skin tension. The image of the skin relief at rest and during the skin folding test was reconstructed by optical confocal microscopy and provided the density of the skin lines printed on the outer surface of the skin. Skin folding test enables the clinician's manual procedure to be instrumented to identify tension lines i.e., Langer lines, for better healing during a surgical procedure. The main directions of natural skin tension deduced from the measured wave speed and the densities of skin lines were [40°-60°] for the forearm and [0°-20°] for the thigh, considering that the longitudinal axis of the body is situated at 90° and the transversal axis at 0°. This method shows the remarkable effect of age and body area on the mechanical behavior of human skin in vivo. The elastic properties and natural tension of the skin decrease with age. This decrease is greater in the directions orthogonal to the skin's tension lines, leading to the accentuation of the anisotropic behavior of the cutaneous tissue. The main direction of skin tension is highly dependent on the area of the body and is directed towards a preferred direction which corresponds to the main direction of skin tension.

Evaluation of a new connected portable camera for the analysis of skin microrelief and the assessment of the effect of skin moisturisers.

BACKGROUND: Silicone replicas and non-contact methods are effective methods to analyse the micrometric scale of the skin microrelief. Yet, they imply data capture in research facilities. The capabilities of a new connected portable camera were evaluated to analyse microrelief under nomadic conditions, also studying the effect of moisturisers. MATERIALS AND METHODS: 3D depth maps were constructed using shape-from-shading algorithms. Roughness heterogeneity (Spa) was computed, and skin profiles were extracted to calculate roughness amplitude (Ra, Rq), as well as furrows/plateaus characteristics. Validation of the connected camera was performed on tanned cowhide leather and on the inner forearm skin of a single subject. The forearms of 18 subjects (23-60 years old) were also evaluated. While living their regular life, they self-performed triplicate acquisitions at various times. The effects of a placebo and of cream containing moisturisers-saccharide isomerate, urea or xylitylglucoside-anhydroxylitol-xylitol-were investigated, using untreated control skin as a reference. RESULTS: Validation of the device on leather and forearm skin shows high repeatability. The 18 subjects show the known correlation between age and changes in microrelief. While testing formulas, 8 h after a single application, all decreased Spa (-1.6/-2.1 folds). Only saccharide isomerate and xylitylglucoside-anhydroxylitol-xylitol decreased Ra (-2.4/-2.8 folds). The sectional area of plateaus was reduced from -1.5 (urea) to -2.1 folds (xylitylglucoside-anhydroxylitol-xylitol). The height of plateaus is also decreased by all moisturisers, from -1.5 (urea) to -2.1 folds (xylitylglucoside-anhydroxylitol-xylitol). CONCLUSION: This novel camera device enables microrelief analysis under nomadic conditions, allowing monitoring its changes along the day and upon moisturisers' application.

Bite injuries to the hand and forearm: analysis of hospital stay, treatment and costs.

We retrospectively reviewed the charts of patients treated for bite injuries in our clinic from 2014 to 2019. The time from the bite event to surgery, duration of hospital stay, duration of antibiotic treatment, complications, incapacity for work and costs were analysed. Cat bites were compared with the other bite injuries and were found to be more problematic. The results of early (within 24 hours) and delayed treatment in cat bite injuries were compared. Treated early they were associated with a shorter hospital stay (1.4 versus 2.4 days), shorter duration of antibiotic treatment (9.7 versus 12.6 days), lower complication rate (10% versus 18%), lower cost (CHF4606 versus 8072) (£4061 versus £7116; US$4771 versus US$8361; €4788 versus €8390) and a shorter incapacity for work (15 versus 43 days). Surgical treatment must be carried out as early as possible. The public and physicians require education to reduce the frequency of these injuries and the associated costs.Level of evidence: IV.

Paediatric forearm fractures: assessment and initial management.

The forearm is the most common site of fracture in children. At the time of initial assessment, a thorough examination and neurovascular assessment of the limb is necessary. X-rays allow evaluation of the fracture location and type, in addition to the degree of displacement. With the help of intranasal opiates, manipulation of fracture fragments can be performed in the emergency department. Immobilisation in plaster is the gold standard treatment for paediatric forearm fractures where the degree of displacement is within acceptable parameters. Manipulation and casting should be followed by orthogonal radiographs and a repeated neurovascular assessment of the limb. Oral analgesia and safety netting information should be provided on discharge and the child should be reviewed in fracture clinic within a week of the injury. This article reviews the British Orthopaedic Association Standards for Trauma and Orthopaedics for the early management of paediatric forearm fractures that do not require operative management.

Biomechanical assessment of the central band of the interosseous membrane using shear wave elastography: reliability and reproducibility.

The interosseous membrane of the forearm is an essential structure for the stability of the forearm skeleton, the most important part being the central band. The purpose of this study was to determine if shear wave elastography, a non-invasive ultrasound technique, can be used to measure shear wave speed in the central band and quantify stiffness. Fifteen healthy adult subjects were included (30 forearms). The participants forearms were positioned on an articulated plate, with their hand in neutral, pronated and then supinated positions of 30°, 60° and 90°. The shear wave speed was highest in 90° pronation (4.4 m/s (SD 0.3)) and 90° supination (4.4 m/s (SD 0.27)) indicating maximum stiffness in these positions. Its minimum value was in the neutral position, and either in 30° pronation or supination (3.5 m/s (SD 0.3)). Intra- and interobserver agreement was excellent, regardless of probe positioning or forearm mobilization. This study presents a reliable shear wave elastography measurement protocol to describe the physiological function of the central band of the interosseous membrane in healthy adults.Level of evidence: IV.

Assessment of Ethno-racial and Insurance-based Disparities in Pediatric Forearm and Tibial Fracture Care in the United States.

INTRODUCTION: Despite growing attention to healthcare disparities and interventions to improve inequalities, additional identification of disparities is needed, particularly in the pediatric population. We used state and nationwide databases to identify factors associated with the surgical treatment of pediatric forearm and tibial fractures. METHODS: The Healthcare Cost and Utilization Project State Inpatient, Emergency Department, and Ambulatory Surgery and Services Databases from four US states and the Nationwide Emergency Department Sample database were quarried using International Classification of Diseases codes to identify patients from 2006 to 2015. Multivariable regression models were used to determine factors associated with surgical treatment. RESULTS: State databases identified 130,006 forearm (1575 open) and 51,979 tibial fractures (1339 open). Surgical treatment was done in 2.6% of closed and 37.5% of open forearm fractures and 7.9% of closed and 60.5% of open tibial fractures. A national estimated total of 3,312,807 closed and 46,569 open forearm fractures were included, 59,024 (1.8%) of which were treated surgically. A total of 719,374 closed and 26,144 open tibial fractures were identified; 52,506 (7.0%) were treated surgically. Multivariable regression revealed that race and/or insurance status were independent predictors for the lower likelihood of surgery in 3 of 4 groups: Black patients were 43% and 35% less likely to have surgery after closed and open forearm fractures, respectively, and patients with Medicaid were less often treated surgically for open tibial fractures in state (17%) and nationwide (20%) databases. CONCLUSIONS: Disparities in pediatric forearm and tibial fracture care persist, especially for Black patients and those with Medicaid; identification of influencing factors and interventions to address them are important in improving equality and value of care.

Functional and biomechanical assessment of the hand following ulnar forearm free flap transfer: Prospective self-controlled study.

BACKGROUND: There is a shortage of well-designed self-controlled studies evaluating hand biomechanics following ulnar forearm flap (UFF) harvest. This study was conducted to evaluate objective and subjective functional outcomes of the donor's hand following UFF harvest. METHODS: All patients undergoing UFF were included for analysis. Grip strength, wrist movement, forearm supination and pronation, pinch strengths, sensation to light touch and temperature, and hand dexterity were assessed preoperatively and at 1, 3, and 6 months postoperatively. In addition, DASH score (disabilities of the arm, shoulder, and hand score) and Patient and Observer Scar Assessment Scale (POSAS) were analyzed. RESULTS: A total of 18 patients were enrolled. A significant reduction in grip strength for donor's hand was observed between preoperative and postoperative 1 and 3 months (mean difference = 14 kg, 7.38 kg, respectively, p = 0.000 for all). A similar trend was observed for pinch strength and range of motion (p < 0.05). Three months after surgery, there is still a significant reduction in tip pinch, tripod pinch, wrist extension, and supination. All biomechanics outcomes returned to preoperative baseline at 6 months after surgery. No patients suffered significant changes in sensation to light touch, temperature, and numbness by 6 months. There was a significant increase in DASH score by 3.37 points 6 months after operation (p = 0.000). The POSAS score indicates satisfaction with the appearance of the donor site. CONCLUSIONS: UFF is a safe and reliable option for oral cavity reconstruction with minimum donor site morbidities, mainly when cosmesis is paramount. Furthermore, objective hand biomechanics ultimately returns to its preoperative state within 6 months after surgery.

The Gantzer transfer - Assessment of the feasibility of using the nerve supplying the Gantzer muscle for end-to-side supercharging of the ulnar nerve.

Our study aimed at assessing the anatomical feasibility of using the nerve supplying the Gantzer muscle (GM) to supercharge the ulnar nerve following injury. The GM nerve was dissected and measured in 36 forearms. The distance between its origin and the lateral epicondyle of humerus and between the GM nerve and the ulnar nerve was measured. The GM was present in 15 forearms (47%). The average distance between the origin of the GM nerve and the lateral epicondyle was 7.34 cm (range 3.3-9.1 cm). The average length of the GM nerve was 3.05 cm (range 1.6-4.5 cm) from origin to neuromuscular junction. The average distance from the ulnar nerve was 2.56 cm (range 1.8-13 3.4 cm). The length of the GM nerve was significantly greater (p < 0.05) than the perpendicular distance between its origin and the ulnar nerve, allowing ample margin for side-to-side or end-to-side supercharging of the ulnar nerve with minimal or no need for further translocation or dissection. The use of the GM nerve as donor following ulnar nerve injury may provide an alternative to the pronator quadratus nerve for supercharged end-to-side transfer, or as an addition, thus supercharging the ulnar nerve twice.

Muscle thickness assessment of the forearm via ultrasonography: is experience level important?

It is suggested that experience is needed in order to capture valid estimates of muscle size with ultrasound. However, it is unknown whether there is a large degree of skill needed to analyze the images once they are captured.Objective.To determine if less experienced raters could accurately analyze ultrasound images of the forearm by comparing their estimates with those of a very experienced ultrasonographer (criterion).Approach.50 muscle thickness images were captured by one experienced ultrasonographer (also Rater 1). Those images were saved and were then measured by four raters with different levels of experience. The rater who captured the images was very experienced (criterion), the second rater was also experienced and provided 5 minutes of instruction for Rater 3 (minimal experience) and Rater 4 (no experience). Test-retest reliability was also determined for Rater 3 and 4.Main Results.The average muscle thickness value for the criterion was 3.73 cm. The constant error for Rater 2, 3, and 4 was -0.003 (0.02) cm (p= 0.362), -0.07 (0.04) cm (p< 0.001), and 0.02 (0.09) cm (p= 0.132), respectively. The SD for Rater 4 was greater, resulting in wider limits of agreement compared to Rater 2 and 3. Absolute error was 0.01 cm for Rater 2, whilst it was 0.07 cm and 0.03 cm for the two inexperienced raters (Rater 3 and 4). The error for Rater 3 was systematic and post-hoc assessment found that this rater was using a different border than the other three raters (but consistent across time). For the test-retest reliability, the minimal difference for Rater 3 was 0.08 cm (relative minimal difference of 2%) and 0.17 cm (relative minimal difference of 4%) for Rater 4.Significance.Less experienced raters were able to accurately and reliably analyze already captured muscle thickness images of the forearm with low absolute errors.

Antecubital Vein Cannula Position Impacts Assessment of Forearm Glucose Uptake During an Oral Glucose Challenge in Healthy Volunteers.

INTRODUCTION: Skeletal muscle is a major site for whole-body glucose disposal, and determination of skeletal muscle glucose uptake is an important metabolic measurement, particularly in research focussed on interventions that impact muscle insulin sensitivity. Calculating arterial-venous difference in blood glucose can be used as an indirect measure for assessing glucose uptake. However, the possibility of multiple tissues contributing to the composition of venous blood, and the differential in glucose uptake kinetics between tissue types, suggests that sampling from different vein sites could influence the estimation of glucose uptake. This study aimed to determine the impact of venous cannula position on calculated forearm glucose uptake following an oral glucose challenge in resting and post-exercise states. MATERIALS AND METHODS: In 9 young, lean, males, the impact of sampling blood from two antecubital vein positions; the perforating vein ('perforating' visit) and, at the bifurcation of superficial and perforating veins ('bifurcation' visit), was assessed. Brachial artery blood flow and arterialised-venous and venous blood glucose concentrations were measured in 3 physiological states; resting-fasted, resting-fed, and fed following intermittent forearm muscle contraction (fed-exercise). RESULTS: Following glucose ingestion, forearm glucose uptake area under the curve was greater for the 'perforating' than for the 'bifurcation' visit in the resting-fed (5.92±1.56 vs. 3.69±1.35 mmol/60 min, P<0.01) and fed-exercise (17.38±7.73 vs. 11.40±7.31 mmol/75 min, P<0.05) states. DISCUSSION: Antecubital vein cannula position impacts calculated postprandial forearm glucose uptake. These findings have implications for longitudinal intervention studies where serial determination of forearm glucose uptake is required.

Supraclavicular Artery Island Flap: Critical Appraisal and Comparison to Alternate Reconstruction.

OBJECTIVES/HYPOTHESIS: The supraclavicular artery island (SAI) flap may be a good option for selected head and neck reconstruction due to its reliability, ease of harvest, and favorable color match. The objective of this study was to examine the rates of complications for the SAI flap in head and neck oncologic reconstruction, with examination of risk factors and comparisons to alternative flaps often considered the gold-standard soft-tissue flaps for head and neck reconstruction: the pectoralis myocutaneous (PMC), radial forearm free flap (RFFF), and anterolateral thigh (ALT) flaps. STUDY DESIGN: Retrospective cohort study. METHODS: Consecutive SAI flaps were compared to PMC, RFFF, and ALT flaps (non-SAI flap group), all performed by the senior author from 2010 to 2018. The non-SAI flaps were included if an SAI flap could have been performed as an alternate flap. The groups were compared based on demographics, flap dimensions, site of reconstruction, operating time, total hospital stay, total hospital costs, and complications. RESULTS: One hundred seven SAI flaps and 194 non-SAI flaps were identified. SAI flaps were used less commonly than non-SAI flaps for mucosal defects (P < .001). The SAI flap dimensions were narrower but longer than non-SAI flaps (P < .001). SAI flaps had higher rates of total complications, partial flap necrosis, flap dehiscence at the recipient site, fistula, donor site dehiscence, and minor complications compared to non-SAI flaps (all P < .05). SAI flaps had higher rates of total complications, recipient site dehiscence, fistula, and minor complications in both the oral cavity and all mucosal sites compared to non-SAI flaps (all P < .05). SAI flaps for mucosal reconstruction were associated with higher rates of total complications (54% vs. 34%, P = .04), flap dehiscence at the recipient site (32% vs. 14%, P = .03), and major complications (21% vs. 5%, P = .02), compared to cutaneous reconstruction. Complications were equivalent between SAI flaps and non-SAI flaps for cutaneous reconstruction (all P > .05). Multivariate analysis showed that SAI flaps were associated with any postoperative complication (odds ratio [OR]: 3.47, 95% confidence interval [CI]: 1.85-6.54), partial flap necrosis (OR: 5.69, 95% CI: 1.83-17.7), flap dehiscence (OR: 5.36, 95% CI: 2.29-12.5), donor site complications (OR: 11.6, 95% CI: 3.27-41.0), and minor complications (OR: 5.17, 95% CI: 2.42-11.0). Within the SAI flap group, SAI flap length >24 cm was associated with postoperative complications on multivariate analysis (OR: 5.09, 95% CI: 1.02-25.5, P = .048). CONCLUSIONS: The SAI flap is best suited for cutaneous reconstruction of the face, neck, and parotid/temporal bone regions due to the favorable color match; the thin, pliable nature of the skin; ease of harvest; and equivalent complication rates compared to alternate soft-tissue flaps. However, the SAI flap is associated with more complications for oral cavity and mucosal site reconstruction when compared to RFFF and ALT flaps and should be used in selected cases that do not require complex folding. For all sites, flaps longer than 24 cm should be used with caution. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:S1-S14, 2022.