The effect of forearm rotation on the bone mineral density measurements of the distal radius.

INTRODUCTION: Forearm dual-energy X-ray absorptiometry (DXA) is often performed in clinics where central DXA is unavailable. Accurate bone mineral density (BMD) measurement is crucial for clinical assessment. Forearm rotation can affect BMD measurements, but this effect remains uncertain. Thus, we aimed to conduct a simulation study using CT images to clarify the effect of forearm rotation on BMD measurements. MATERIALS AND METHODS: Forearm CT images of 60 women were analyzed. BMD was measured at the total, ultra-distal (UD), mid-distal (MD), and distal 33% radius regions with the radius located at the neutral position using digitally reconstructed radiographs generated from CT images. Then, the rotation was altered from - 30° to 30° (supination set as positive) with a one-degree increment, and the percent BMD changes from the neutral position were quantified for all regions at each angle for each patient. RESULTS: The maximum mean BMD changes were 5.8%, 7.0%, 6.2%, and 7.2% for the total, UD, MD, and distal 33% radius regions, respectively. The analysis of the absolute values of the percent BMD changes from the neutral position showed that BMD changes of all patients remained within 2% when the rotation was between - 5° and 7° for the total region, between - 3° and 2° for the UD region, between - 4° and 3° for the MD region, and between - 3° and 1° for the distal 33% radius region. CONCLUSION: Subtle rotational changes affected the BMD measurement of each region. The results showed the importance of forearm positioning when measuring the distal radius BMD.

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.

Ulnar lengthening for children with forearm deformity from hereditary multiple exostoses: a retrospective study from a tertiary medical center.

BACKGROUND: Patients with hereditary multiple exostosis (HME) usually present with forearm deformity with or without radial head dislocation. Ulna lengthening has been proposed to address this condition. Exostosis resection plus ulna lengthening has been adopted in our hospital since 2008, and patients with this condition were retrospectively reviewed. Herein, we aimed to investigate the optimal timing and clinical outcomes of this surgical approach. METHODS: In all, thirty-five patients (40 forearms), including 22 boys and 13 girls, were enrolled in our study from July 2014 to September 2020. We divided the patients into 4 groups based on the age when they received surgery and the status of the radial head. Pronation and supination of the forearm, flexion and extension of the elbow, wrist ulnar deviation and wrist radial deviation, and radiological parameters including ulnar length (UL), ulnar variance (UV), the percentage of radial bowing (RB/RL), radio articular angle (RAA) and carpal slip (CS), were assessed and recorded. RESULTS: The mean UL was significantly improved after surgery in four Groups (P<0.05). In patients with radial head dislocation, we found significant improvement in forearm, wrist function and elbow flexion (p < 0.05). For the patients with radial head dislocation, the juniors demonstrated better improvement in % RB and RAA (p<0.05, p = 0.003 and 0.031). CONCLUSION: Exostosis resection and ulna lengthening with unilateral external fixation can effectively improve the function and radiological parameters of forearm deformity in HME children. For patients with radial head dislocation, early surgery can achieve better results. For patients not associated with radial head dislocation, we recommend regular follow-up and surgical treatment after 10 years of age.

Opportunistic hand radiographs to screen for low forearm bone mineral density: a prospective and retrospective cohort study.

BACKGROUND: Low bone mineral density affects 53% of women over age 65 in the US, yet many are unaware and remain untreated. Underdiagnosis of forearm osteoporosis and related fragility fractures represent missed warning signs of more deadly, future fractures. This study aimed to determine if hand radiographs could serve as early, simple screening tools for predicting low forearm bone mineral density (BMD). METHODS: We evaluated posterior-anterior (PA) hand radiographs (x-rays) and Dual-energy X-ray absorptiometry (DXA) scans of 43 participants. The ratio of the intramedullary cavity to total cortical diameter of the second metacarpal (second metacarpal cortical percentage (2MCP)) was used as a potential diagnostic marker. Mixed-effects linear regression was performed to determine correlation of 2MCP with BMD from various anatomic regions. Repeated measures ANOVAs were used to compare BMD across sites. An optimal 2MCP cutoff for predicting forearm osteopenia and osteoporosis was found using Receiver Operating Curves. RESULTS: 2MCP is directly correlated with BMD in the forearm. The optimal 2MCP of 48.3% had 80% sensitivity for detecting osteoporosis of the 1/3 distal forearm. An 2MCP cutoff of 50.8% had 84% sensitivity to detect osteoporosis of the most distal forearm. Both 2MCP cutoffs were more sensitive at predicting forearm osteoporosis than femoral neck T-scores. CONCLUSIONS: These findings support the expansion of osteoporosis screening to include low-cost hand x-rays, aiming to increase diagnosis and treatment of low forearm BMD and fractures. Proposed next steps include confirming the optimal 2MCP cutoff at scale and integrating automatic 2MCP measurements into PAC systems.

Does forearm referencing using a retroversion guide achieve the targeted retroversion of the humeral component in reverse shoulder arthroplasty?

BACKGROUND: Component positioning affects clinical outcomes of reverse shoulder arthroplasty, which necessitates an implantation technique that is reproducible, consistent, and reliable. This study aims to assess the accuracy and precision of positioning the humeral component in planned retroversion using a forearm referencing guide. METHODS: Computed tomography scans of 54 patients (27 males and 27 females) who underwent primary reverse shoulder arthroplasty for osteoarthritis or cuff tear arthropathy were evaluated. A standardized surgical technique was used to place the humeral stem in 15° of retroversion. Version was assessed intraoperatively visualizing the retroversion guide from above and referencing the forearm axis. Metal subtraction techniques from postoperative computed tomography images allowed for the generation of 3D models of the humerus and for evaluation of the humeral component position. Anatomical humeral plane and implant planes were defined and the retroversion 3D angle between identified planes was recorded for each patient. Accuracy and precision were assessed. A subgroup analysis evaluated differences between male and female patients. RESULTS: The humeral retroversion angle ranged from 0.9° to 22.8°. The majority (81%) of the measurements were less than 15°. Mean retroversion angle (±SD) was 9.9° ± 5.8° (95% CI 8.4°-11.5°) with a mean percent error with respect to 15° of -34% ± 38 (95% CI -23 to -44). In the male subgroup (n = 27, range 3.8°-22.5°), the mean retroversion angle was 11.9° ± 5.4° (95% CI 9.8°-14.1°) with a mean percent error with respect to 15° of -21% ± 36 (95% CI -6 to -35). In the female subgroup (n = 27, range 0.9°-22.8°), mean retroversion angle was 8.0° ± 5.5° (95% CI 5.8°-10.1°) and the mean percent error with respect to 15° was -47% ± 36 (95% CI -32 to -61). The differences between the 2 gender groups were statistically significant (P = .006). CONCLUSION: Referencing the forearm using an extramedullary forearm referencing system to position the humeral stem in a desired retroversion is neither accurate nor precise. There is a nonnegligible tendency to achieve a lower retroversion than planned, and the error is more marked in females.

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.

Precision errors and least significant changes in paediatric forearm measurements of bone density, mass, dimensions, mechanostat parameters and soft tissue composition by Stratec XCT-2000L.

OBJECTIVES: The peripheral quantitative computed tomography (pQCT) is gaining popularity in the field of paediatric densitometry, however, very little is known about the precision errors of this method in diseased children. The aim of the study was to evaluate the precision errors of bone density, mass, dimensions, strength, mechanostat parameters and soft tissue at the forearm in diseased children. METHODS: Stratec XCT 2000L apparatus was used. The measurement sites were 4% and 66% of the forearm length. The study group consisted of 60 patients (31 girls) aged 5,7-18,0 yrs. RESULTS: We observed week relationships between precision errors and body size with r from -0,37 to 0,28. Relative precision errors (CV%RMS) were from 0,85% for radius 66% cortical bone density to 3,82% for fat cross-sectional area to muscle cross-sectional area ratio. Least significant change (LSC) was from 2,73% to 10,59%, respectively. CONCLUSION: Presented study reveal pQCT method at the forearm in diseased children as relatively precise technique. The results may help with planning and interpretation of pQCT studies in diseased children.

The clinical necessity of a distal forearm DEXA scan for predicting distal radius fracture in elderly females: a retrospective case-control study.

BACKGROUND: Recent studies have demonstrated that the distal forearm dual-energy X-ray absorptiometry (DEXA) scan might be a better method for screening bone mineral density (BMD) and the risk of a distal forearm fracture, compared with a central DEXA scan. Therefore, the purpose of this study was to determine the effectiveness of a distal forearm DEXA scan for predicting the occurrence of a distal radius fracture (DRF) in elderly females who were not initially diagnosed with osteoporosis after a central DEXA scan. METHODS: Among the female patients who visited our institutes and who were over 50 years old and underwent DEXA scans at 3 sites (lumbar spine, proximal femur, and distal forearm), 228 patients with DRF (group 1) and 228 propensity score-matched patients without fractures (group 2) were included in this study. The patients' general characteristics, BMD, and T-scores were compared. The odds ratios (OR) of each measurement and correlation ratio among BMD values of the different sites were evaluated. RESULTS: The distal forearm T-score of the elderly females with DRF (group 1) was significantly lower than that of the control group (group 2) (p < 0.001 for the one-third radius and ultradistal radius measurements). BMD measured during the distal forearm DEXA scan was a better predictor of DRF risk than BMD measured during the central DEXA (OR = 2.33; p = 0.031 for the one-third radius, and OR = 3.98; p < 0.001 for the ultradistal radius). The distal one-third radius BMD was correlated with hip BMD, rather than lumbar BMD (p < 0.05 in each group). CONCLUSION: Performing a distal forearm DEXA scan in addition to a central DEXA scan appears to be clinically significant for detecting the low BMD in the distal radius, which is associated with osteoporotic DRF in elderly females. LEVEL OF EVIDENCE: III; case-control study.

Deep branch of the radial nerve: effect of pronation/supination on longitudinal nerve alignment.

OBJECTIVE: To evaluate the effect of maximal pronation and supination of the forearm on the alignment and anatomic relationship of the deep branch of the radial nerve (DBRN) at the superior arcade of the supinator muscle (SASM) by using high-resolution ultrasound (HRUS). MATERIALS AND METHODS: In this cross-sectional study, HRUS in the long axis of the DBRN was performed in asymptomatic participants enrolled from March to August 2021. DBRN alignment was evaluated by measuring angles of the nerve in maximal pronation and maximal supination of the forearm independently by two musculoskeletal radiologists. Forearm range of motion and biometric measurements were recorded. Student t, Shapiro-Wilk, Pearson correlation, reliability analyses, and Kruskal-Wallis test were used. RESULTS: The study population included 110 nerves from 55 asymptomatic participants (median age, 37.0 years; age range, 16-63 years; 29 [52.7%] women). There was a statistically significant difference between the DBRN angle in maximal supination and maximal pronation (Reader 1: 95% CI: 5.74, 8.21, p < 0.001, and Reader 2: 95% CI: 5.82, 8.37, p < 0.001). The mean difference between the angles in maximal supination and maximal pronation was approximately 7° for both readers. ICC was very good for intraobserver agreement (Reader1: r ≥ 0.92, p < 0.001; Reader 2: r ≥ 0.93, p < 0.001), as well as for interobserver agreement (phase 1: r ≥ 0.87, p < 0.001; phase 2: r ≥ 0.90, p < 0.001). CONCLUSION: The extremes of the rotational movement of the forearm affect the longitudinal morphology and anatomic relationships of the DBRN, primarily demonstrating the convergence of the nerve towards the SASM in maximal pronation and divergence in maximal supination.

The interosseous tuberosities of the forearm exist from 1-year-old: a pediatric radiological study describing the ages of appearance of the different forearm reliefs.

PURPOSE: Interosseous tuberosities have been described in adults on the radial and ulnar sides. However, their presence at birth and their development during growth is still unknown. The objective of this work is to establish the age of onset of this tuberosity among a cohort of children aged 1-year-old or older. METHODS: All anterior-posterior and lateral radiographs performed in our hospital during a consecutive period of 6 months were retrospectively analyzed. Exclusion criteria were: presence of a fracture, a tumor, an age higher than 16 years, radiograph not performed strictly from the front with supination or from the side. On the anterior-posterior radiograph, the presence of the following structures was sought: radial interosseous tuberosity and determination of its length and width; the appearance of the epiphyseal nucleus of the radial head, of the bicipital tuberosity, and of the distal epiphysis. On the lateral views, the presence of the following structures was sought: ulnar interosseous tuberosity and determination of its length and width; the appearance of the olecranon epiphyseal nucleus, and the distal epiphysis. RESULTS: Over the review period, anterior-posterior and lateral radiographs were performed on 368 consecutive children. Finally, 179 patients were included in the radiographic analysis. The radial and ulnar interosseous tuberosities and bicipital tuberosity were present in all cases, from 1-year-old. Only the distal radial epiphysis began to appear at the age of one year, the others ossifying progressively during growth. CONCLUSION: Tuberositas interossea ulnarii and radii exists, are present from 1-year-old and continue to develop during growth.

The feasibility and reliability of measuring forearm muscle thickness by ultrasound in a geriatric inpatient setting: a cross-sectional pilot study.

BACKGROUND: Given the potential benefits of introducing ultrasound in the clinical assessment of muscle disorders, this study aimed to assess the feasibility and reliability of measuring forearm muscle thickness by ultrasound in a geriatric clinical setting. METHODS: Cross-sectional pilot study in 25 participants (12 patients aged ≥ 70 years in an acute geriatric ward and 13 healthy volunteers aged 25-50 years), assessed by three raters. Muscle thickness measurement was estimated as the distance between the subcutaneous adipose tissue-muscle interface and muscle-bone interface of the radius at 30% proximal of the distance between the styloid process and distal insertion of the biceps brachii muscle of the dominant forearm. Examinations were repeated three times by each rater and intra- and inter-rater reliability was calculated. Feasibility analysis included consideration of technological, economic, legal, operational, and scheduling (TELOS) components. RESULTS: Mean muscle-thickness measurement difference between groups was 4.4 mm (95% confidence interval [CI] 2.4 mm to 6.3 mm], p < 0.001). Intra-rater reliability of muscle-thickness assessment was excellent, with intraclass correlation coefficient (ICC) of 0.947 (95%CI 0.902 to 0.974), 0.969 (95%CI 0.942 to 0.985), and 0.950 (95%CI 0.907 to 0.975) for observer A, B, and C, respectively. Inter-rater comparison showed good agreement (ICC of 0.873 [95%CI 0.73 to 0.94]). Four of the 17 TELOS components considered led to specific recommendations to improve the procedure's feasibility in clinical practice. CONCLUSION: Our findings suggest that US is a feasible tool to assess the thickness of the forearm muscles with good inter-rater and excellent intra-rater reliability in a sample of hospitalized geriatric patients, making it a promising option for use in clinical practice.

Point-of-Care Ultrasound Pronator Quadratus Hematoma Sign for Detection of Clinically Non-Angulated Pediatric Distal Forearm Fractures: A Prospective Cohort Study.

OBJECTIVES: Point-of-care ultrasound (POCUS) diagnosis of distal forearm fractures relies on the identification of buckling or breach of hyperechoic bone cortex. We describe the pronator quadratus hematoma (PQH) formation visualized on POCUS, the PQH sign, as it may aid diagnosis of pediatric distal forearm cortical breach fractures. METHODS: A prospective cohort of children presenting to an emergency department with isolated, clinically non-angulated distal forearm injuries received POCUS by an expert emergency physician sonologist who identified the presence or absence of the PQH sign. They secondarily recorded the difference between the size of the pronator quadratus (PQ) muscle on both the affected and non-affected forearms (PQ delta thickness). Children received an x-ray subsequent to POCUS and were diagnosed based on an x-ray reported by a radiologist masked to POCUS findings. RESULTS: Thirty-eight children were recruited. All 22 patients with cortical breach fracture had PQH sign present (100%; 95%CI: 85-100%), while all 16 patients without cortical breach fracture had PQH sign absent (100%; 95%CI: 79-100%). PQ delta thickness ranged from 2.1 to 10.2 mm in cortical breach fractures, 0.0 to 1.1 mm in buckle fractures, and 0.2 to 0.8 mm in patients without fracture. CONCLUSIONS: The PQH sign correctly distinguished all children with, and without, cortical breach fractures. All PQ delta thicknesses were ≧2.1 mm when cortical breach fracture was present and ≦1.1 mm when cortical breach fracture was absent. The PQH sign and PQ delta thickness are promising measurements to identify pediatric distal forearm cortical breach fractures, and their utility should be confirmed in larger studies with sonologists of different abilities.

Prescreening for osteoporosis with forearm bone densitometry in health examination population.

BACKGROUND: Early detection and timely prophylaxis can retard the progression of osteoporosis. The purpose of this study was to determine the validity of peripheral Dual Energy X-ray Absorptiometry (DXA) test for osteoporosis screening. We examined peripheral bone mineral density (BMD) using AKDX-09 W-I DXA densitometer. Firstly, we acquired BMD data from manufacturer-supplied density-gradient phantoms and 30 volunteers to investigate its accuracy and precision, then we measured BMD for 150 volunteers using both AKDX (left forearm) and Hologic Discovery Wi (left forearm, left hip and L1 - L4 vertebrae) simultaneously. Correlation relationship of BMD results acquired from two instruments was assessed by simple linear regression analysis, the Receiver Operating Characteristic (ROC) curves and Areas Under the Curves (AUCs) were evaluated for the diagnostic value of left forearm BMD measured by AKDX in detecting osteoporosis. RESULTS: In vitro precision errors of AKDX BMD were 0.40, 0.20, 0.19%, respectively, on low-, medium-, and high-density phantom; in vivo precision was 1.65%. Positive correlation was observed between BMD measured by AKDX and Hologic at the forearm (r = 0.670), L1-L4 (r = 0.430, femoral neck (r = 0.449), and total hip (r = 0.559). With Hologic measured T-score as the gold standard, the sensitivity of AKDX T-score < - 1 for identifying suboptimal bone health was 63.0 and 76.1%, respectively, at the distal one-third radius and at any site, and the specificity was 73.9 and 90.0%, respectively; the AUCs were 0.708 and 0.879. The sensitivity of AKDX T-score ≤ - 2.5 for identifying osteoporosis at the distal one-third radius and at any site was 76.9 and70.4%, respectively, and the specificity was 80.4 and 78.0%, respectively; the AUCs were 0.823 and 0.778. CONCLUSIONS: Peripheral DXA appears to be a reliable tool for prescreening for osteoporosis.

Percutaneous implantation of peripherally inserted totally implantable venous access systems in the forearm in adolescent patients.

BACKGROUND: Children with different underlying malignant diseases require long-term central venous access. As for port systems in a pectoral position, peripherally implanted port systems in the forearm revealed high levels of technical and clinical success in adult cohorts. OBJECTIVE: To investigate the technical and clinical outcomes of percutaneous central venous port implantation in the forearm in adolescents. MATERIALS AND METHODS: Between April 2010 and August 2020, 32 children ages 9 to 17 years with underlying malignancy received 35 totally implantable venous access ports (TIVAPs) in the forearm. All venous port systems were peripherally inserted under ultrasound guidance. Correct catheter placement was controlled by fluoroscopy. As primary endpoints, the technical success, rate of complications and catheter maintenance were analyzed. Secondary endpoints were the side of implantation, vein of catheter access, laboratory results on the day of the procedure, procedural radiation exposure, amount of contrast agent and reasons for port device removal. RESULTS: Percutaneous TIVAP placement under sonographic guidance was technically successful in 34 of 35 procedures (97.1%). Procedure-related complications did not occur. During the follow-up, 13,684 catheter days were analyzed, revealing 11 complications (0.8 per 1,000 catheter-duration days), Of these 11 complications, 7 were major and 10 occurred late. In seven cases, the port device had to be removed; removal-related complications did not occur. CONCLUSION: Peripheral TIVAP placement in the forearms of children is a feasible, effective and safe technique with good midterm outcome. As results are comparable with standard access routes, this technique may be offered as an alternative when intermittent venous access is required.

High-resolution ultrasound demonstrates in vivo effects of wrist movement on the median nerve along the forearm.

INTRODUCTION/AIMS: High-resolution ultrasound (HRUS) is the imaging method of choice to visualize peripheral nerve size, structure, and biomechanical performance. The purpose of this study was to show and quantify the effects of active and passive wrist alignment on median nerve (MN) cross-sectional area (CSA) along the forearm in a healthy population. METHODS: Sixteen healthy volunteers underwent HRUS of their dominant forearm (n = 16, 10 males, 6 females, 18-55 y of age). Median nerve's CSA was assessed at four defined areas on the forearm in relation to active and passive wrist alignment. RESULTS: Changes in wrist alignment were significantly associated with MN CSA (P < .001), regardless if the wrist was moved actively or passively. MN CSA was lowest during passive extension of the wrist joint and highest during passive flexion of the wrist joint (range: 4.5-23.2 mm2 ). DISCUSSION: The elasticity of nerve tissue, the loose connective tissue between the fascicles, and the paraneurium allow peripheral nerves to adapt to longitudinal strain. HRUS enables the demonstration of significant median nerve CSA changes along the forearm during active and passive wrist movement in healthy volunteers.

Computed Tomography Evaluation of Forearm and Hand Muscles in Patients With Distal Radius Fracture.

INTRODUCTION: Computed tomography (CT) can be used to assess bone status with measurement of Hounsfield unit (HU). The objective of this study was to evaluate whether HU of muscle might be associated with parameters of bone and muscle status. METHODS: We reviewed 71 women aged over 50 yr of age who had distal radius fracture and underwent CT evaluation of affected wrist. We assessed HUs of forearm flexor muscles (flexor digitorum superficialis) and thenar muscles and bone HUs at the capitate and the ulnar head. Other parameters included femur neck and lumbar bone mineral density (BMD), upper extremity lean mass, hand grip strength, and muscle fiber cross-sectional area. We performed correlation analyses to determine associations between variables. RESULTS: Thenar and forearm muscle HUs were significantly correlated with each other, but not with other parameters. HUs of the capitate and ulnar head were positively correlated with femur neck and lumbar BMDs and inversely correlated with age. Ulnar head HU was positively correlated hand grip strength. CONCLUSIONS: HUs of forearm and thenar muscles did not show significant correlations with bone or muscle parameters, although bone HUs correlated well with bone mineral densities. These results support the opportunistic use of CT for evaluating bone fragility. Clinical usefulness of muscle HU measurement needs further studies.

Blood flow changes in the forearm arteries after ultrasound-guided costoclavicular brachial plexus blocks: a prospective observational study.

BACKGROUND: An increase in blood flow in the forearm arteries has been reported after brachial plexus block (BPB). However, few studies have quantitatively analysed the blood flow of the forearm arteries after BPB or have studied only partial haemodynamic parameters. The purpose of the present study was to comprehensively assess blood flow changes in the distal radial artery (RA) and ulnar artery (UA) after BPB performed via a new costoclavicular space (CCS) approach using colour Doppler ultrasound. METHODS: Thirty patients who underwent amputated finger replantation and received ultrasound-guided costoclavicular BPB were included in the study. The haemodynamic parameters of the RA and UA were recorded before the block and 10 min, 20 min, and 30 min after the block using colour Doppler ultrasound to determine the peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (Vmean), pulsatility index (PI), resistance index (RI) and area. The volumetric flow rate (VFR) was calculated using the formula Q = area×Vmean. The aforementioned parameters were compared not only before and after the BPB but also between the RA and UA. RESULTS: Compared with those of the respective baselines, there was a significant increase in the PSV, EDV, Vmean, area, and VFR and a significant decrease in the PI and RI of the RA and UA 10 min, 20 min, and 30 min post-block. The increase 30 min post-block in EDV (258.68 % in the RA, 279.63 % in the UA) was the most notable, followed by that in the Vmean (183.36 % in the RA, 235.24 % in the UA), and the PSV (139.11 % in the RA, 153.15 % in the UA) changed minimally. The Vmean and VFR of the RA were significantly greater than those of the UA before the BPB; however, there was no significant difference in the VFR between the RA and UA after the BPB. CONCLUSIONS: A costoclavicular BPB can increase blood flow in the forearm arteries. The RA had a higher volumetric flow rate than the UA before the BPB; however, the potential blood supply capacity of the UA was similar to that of the RA after a BPB. TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/searchproj.aspx, clinical trial number: ChiCTR 1900023796, date of registration: June 12, 2019).

Role of high-resolution peripheral nerve magnetic resonance imaging in diagnosing median nerve tethering in a case of both-bone forearm fracture in a child.

Forearm fractures are common injuries in pediatric patients. We present a case of median nerve tethering as a complication of both-bone forearm fracture in a child, with an emphasis on MRI as an appropriate and important complement to clinical and electrodiagnostic examination. Early intervention is essential because delayed surgical management of median nerve tethering can result in poor clinical outcomes as a result of irreversible muscle denervation. In this case, we highlight the importance of MRI to facilitate management, including early surgical intervention when appropriate, in median neuropathy following forearm fractures.

Role of ultrasound-guided perineural injection of the posterior antebrachial cutaneous nerve for diagnosis and potential treatment of chronic lateral elbow pain.

OBJECTIVE: To examine diagnostic and therapeutic utility of novel ultrasound-guided perineural injection of posterior antebrachial cutaneous nerve in chronic lateral elbow pain. MATERIALS AND METHODS: We performed a retrospective analysis of ultrasound-guided perineural injection of the posterior antebrachial cutaneous nerve with local anesthetic with or without corticosteroid in patients with chronic lateral elbow pain. Data variables collected included patient demographics, illness course, diagnostic ultrasound findings, immediate pre- and post-injection pain using numeric rating pain scale between 0 and 10, injection complications, and post-injection outcomes. RESULTS: Fifteen patients (9 females and 6 males) with average age 46.9 (range 16-69 years) underwent 20 perineural injections between 2009 and 2019. Patients had on average 84% reduction in pain immediately after the injection (median pre- and post-procedure numeric rating pain scale of 6 and 0, respectively, p < 0.001). Patients had pain relief for an average of 15 h (range 2-48 h) when only local anesthetic was injected, compared with average pain relief of 26.5 days (range 2 h-43 days) when local anesthetic was combined with corticosteroid, p = 0.01. CONCLUSION: Novel ultrasound-guided perineural anesthetic injections around the posterior antebrachial cutaneous nerve can be performed safely and have diagnostic and potentially therapeutic utility in select patients with chronic refractory lateral elbow pain.

Histoplasmosis tenosynovitis of the forearm and wrist: imaging, surgical and pathologic findings.

Histoplasmosis is a disease endemic to several parts of the world, including South America. It progresses in a mostly asymptomatic and self-limiting manner but has the potential to cause disseminated pulmonary infection, especially in immunocompromised patients. Rare reports from the literature describe musculoskeletal manifestations related to the two varieties of the pathogen that cause histoplasmosis, namely, the capsulatum or duboissi variety. In this report, we describe the case of a previously healthy, middle-aged man, with slowly progressing pain in the right forearm, wrist, and fingers, diagnosed with a case of pathologically confirmed histoplasmosis tenosynovitis. We also describe the imaging, surgical, and histological findings and discuss the differential diagnoses for tenosynovitis, in case of atypical infections.