Assessing the Preservation of Lumbar Lordotic Curvature in Everyday Sitting Conditions Assessed with an Inertial Measurement System.

Background/Objectives: Lumbar lordotic curvature (LLC), closely associated with low back pain (LBP) when decreased, is infrequently assessed in clinical settings due to the spatiotemporal limitations of radiographic methods. To overcome these constraints, this study used an inertial measurement system to compare the magnitude and maintenance of LLC across various sitting conditions, categorized into three aspects: verbal instructions, chair type, and desk task types. Methods: Twenty-nine healthy participants were instructed to sit for 3 min with two wireless sensors placed on the 12th thoracic vertebra and the 2nd sacral vertebra. The lumbar lordotic angle (LLA) was measured using relative angles for the mediolateral axis and comparisons were made within each sitting category. Results: The maintenance of LLA (LLAdev) was significantly smaller when participants were instructed to sit upright (-3.7 ± 3.9°) compared to that of their habitual sitting posture (-1.2 ± 2.4°) (p = 0.001), while the magnitude of LLA (LLAavg) was significantly larger with an upright sitting posture (p = 0.001). LLAdev was significantly larger when using an office chair (-0.4 ± 1.1°) than when using a stool (-3.2 ± 7.1°) (p = 0.033), and LLAavg was also significantly larger with the office chair (p < 0.001). Among the desk tasks, LLAavg was largest during keyboard tasks (p < 0.001), followed by mouse and writing tasks; LLAdev showed a similar trend without statistical significance (keyboard, -1.2 ± 3.0°; mouse, -1.8 ± 2.2°; writing, -2.9 ± 3.1°) (p = 0.067). Conclusions: Our findings suggest that strategies including the use of an office chair and preference for computer work may help preserve LLC, whereas in the case of cueing, repetition may be necessary.

Ultrasonographic features of ulnar nerve instability around the elbow in fresh cadavers.

Ultrasound (US) is commonly used to evaluate ulnar nerve instability (UNI) and snapping of the medial head of the triceps brachii muscle (ST). We aimed to determine the diagnostic accuracy of US in evaluating UNI, through cadaveric dissection, and to evaluate the US features and relationships of UNI and ST according to elbow flexion. Dynamic US was performed with elbow extension, 90° flexion, and full flexion positions on 18 elbows from 9 fresh cadavers. UNI was classified into N (normal), S (subluxation), and D (dislocation) types. On US exams, the following findings and parameters were evaluated: the presence of UNI and ST; the horizontal distance from the apex of the medial epicondyle (ME) to the margins of the UN and medial head of the triceps brachii muscle (ME_UN and ME_TB, respectively); cross-sectional area and flattening ratio (FR) of UN. After US, all cadavers were dissected to expose the UN and TB, and elbow flexion and extension were simulated to confirm UNI and ST. The gross anatomic findings of UNI and ST were consistent with the US findings. In extension and 90° flexion positions, all cases were type N. In full flexion position, types N and S occurred in 10 (56%) and 8 (44%) elbows, respectively. FR and ME_UN in 90° flexion position, FR, ME_UN, and ME_TB in full flexion position differed significantly between types S and N. Positive correlations were found between ME_UN and ME_TB in 90° flexion and full flexion positions. Dynamic US accurately assessed UNI and ST. UNI was positively correlated to medial TB movement.

Scale-attentional U-Net for the segmentation of the median nerve in ultrasound images.

PURPOSE: The aim of this study was to develop a neural network that accurately and effectively segments the median nerve in ultrasound (US) images. METHODS: In total, 1,305 images of the median nerve of 123 normal subjects were used to train and evaluate the model. Four datasets from two measurement regions (wrist and forearm) of the nerve and two US machines were used. The neural network was designed for high accuracy by combining information at multiple scales, as well as for high efficiency to prevent overfitting. The model was designed in two parts (cascaded and factorized convolutions), followed by selfattention over scale and channel features. The precision, recall, dice similarity coefficient (DSC), and Hausdorff distance (HD) were used as performance metrics. The area under the receiver operating characteristic curve (AUC) was also assessed. RESULTS: In the wrist datasets, the proposed network achieved 92.7% and 90.3% precision, 92.4% and 89.8% recall, DSCs of 92.3% and 89.7%, HDs of 5.158 and 4.966, and AUCs of 0.9755 and 0.9399 on two machines. In the forearm datasets, 79.3% and 87.8% precision, 76.0% and 85.0% recall, DSCs of 76.1% and 85.8%, HDs of 5.206 and 4.527, and AUCs of 0.8846 and 0.9150 were achieved. In all datasets, the model developed herein achieved better performance in terms of DSC than previous U-Net-based systems. CONCLUSION: The proposed neural network yields accurate segmentation results to assist clinicians in identifying the median nerve.

Localization of Ulnar Neuropathy at the Wrist Using Motor and Sensory Ulnar Nerve Segmental Studies.

BACKGROUND AND PURPOSE: Diagnosing ulnar neuropathy at the wrist (UNW) is often challenging, and performing several short segmental studies have been suggested for achieving this. We aimed to determine the utility of ulnar nerve segmental studies at the wrist (UNSWs) in patients with suspected UNW. METHODS: Fourteen patients with typical symptoms of unilateral UNW were evaluated using conventional electrophysiological tests, UNSWs, and ultrasonography (US). In UNSWs, the ulnar nerve was stimulated at three sites (3 cm distal, just lateral, and 2 cm proximal to the pisiform), and recordings were made at the first dorsal interosseous (FDI) muscle and the fifth digit. Four types of UNW were identified by conventional ulnar nerve conduction studies based on motor and sensory fiber involvement. UNW was also categorized as either a proximal or distal lesion relative to the pisiform based on the UNSWs. The relationships between the conventional electrophysiological type, UNSW categorization results, and lesion location as verified by US were analyzed. RESULTS: Proximal UNW lesions were associated with involvement of the entire deep motor and the superficial sensory fibers (type I). Distal lesions were more closely related to deep motor fibers that innervated the FDI (type III). All five proximal and six distal lesions seen in US matched the lesion locations found on UNSWs. CONCLUSIONS: Motor and sensory UNSW are considered useful assistive techniques for diagnosing UNW and localizing its lesion sites.

Risk Analysis of Needle Injury to the Long Thoracic Nerve during Ultrasound-Guided C7 Selective Nerve Root Block.

Background and Objectives: Ultrasound (US)-guided cervical selective nerve root block (SNRB) is a widely used treatment for upper limb radicular pain. The long thoracic nerve (LTN) passes through the middle scalene muscle (MSM) at the C7 level. The needle trajectory of US-guided C7 SNRB pierces the MSM, therefore indicating a high probability of injury to the LTN. We aimed to identify the LTN and to investigate the risk of needle injury to the nerve during US-guided C7 SNRB. Materials and Methods: This retrospective observational study included 30 patients who underwent US-guided SNRB at the C7 level in a university hospital. We measured the maximal cross-sectional diameter (MCSD) of the LTN and cross-sectional area (CSA) of the C7 nerve root and assessed the injury risk of LTN during US-guided C7 SNRB by simulating the trajectory of the needle in the ultrasound image. Results: The LTN was detectable in all the cases, located inside and outside the MSM in 19 (63.3%) and 11 (36.7%) of cases, respectively. The LTN's mean MCSD was 2.10 mm (SD 0.13), and the C7 root's CSA was 10.78 mm2 (SD 1.05). The LTN location was within the simulated risk zone in 86.7% (26/30) of cases. Conclusion: Our findings suggest a high potential for LTN injury during US-guided C7 SNRB. The clear visualization of LTNs in the US images implies that US guidance may help avoid nerve damage and make the procedure safer. When performing US-guided C7 SNRB, physicians should take into consideration the location of the LTN.

Ultrasound-Guided Popliteal Nerve Block with Short-Acting Lidocaine in the Surgical Treatment of Ingrown Toenails.

BACKGROUND: Digital nerve block (DB) is a commonly utilized anesthetic procedure in ingrown toenail surgery. However, severe procedure-related pain has been reported. Although the popliteal sciatic nerve block (PB) is widely accepted in foot and ankle surgery, its use in ingrown toenail surgery has not been reported. Therefore, this study aimed to investigate the safety and effectiveness of PB in the surgical treatment of ingrown toenails. METHODS: One-hundred-ten patients surgically treated for an ingrown toenail were enrolled. Sixty-six patients underwent DB, and 44 underwent PB. PB was performed under ultrasound-guidance via a 22-gauge needle with 15 mL of 1% lidocaine in the popliteal region. The visual analogue scale was used to assess pain at two-time points: pain with skin penetration and pain with the solution injection. Time to sensory block, duration of sensory block, need for additional injections, and adverse events were recorded. RESULTS: PB group demonstrated significantly lower procedure-related pain than the DB group. Time to sensory block was significantly longer in the PB group (20.8 ± 4.6 versus 6.5 ± 1.6 minutes). The sensory block duration was significantly longer in the PB group (187.9 ± 22.0 versus 106.5 ± 19.1 minutes). Additional injections were required in 16 (24.2%) DB cases, while no additional injections were required in PB cases. Four adverse events occurred in the DB group and two in the PB group. CONCLUSION: PB was a less painful anesthetic procedure associated with a longer sensory block duration and fewer repeat injections compared with DB. The result of this study implicates that PB can be an alternative anesthetic option in the surgical treatment of ingrown toenails.

Ultrasound-Guided Injection of the Sternocleidomastoid Muscle: A Cadaveric Study with Implications for Chemodenervation.

BACKGROUND: Ultrasound guidance may improve the accuracy of botulinum toxin injection, but studies of its potential for cervical dystonia treatment are lacking. OBJECTIVE: To determine the accuracy of ultrasound-guided injection in the sternocleidomastoid muscle (SCM). DESIGN: Observational study. SETTING: Tertiary care university hospital. PARTICIPANTS: Eighteen embalmed cadavers. INTERVENTIONS: In total, 36 SCMs from 18 embalmed cadavers were examined. One physician performed ultrasound scans to divide each SCM into quarters and evaluated its cross-sectional area (CSA) and thickness at each of three meeting points between adjacent quarters. Under ultrasound guidance, another experienced physician injected methylene blue solution at one of the three points, using the in-plane technique (12 specimens per point; right SCM 3 mL, left SCM 5 mL). One anatomist dissected all cadavers and measured the distance of dye dispersion along the longitudinal axis of each muscle. Dispersion ratio was calculated as longitudinal dye dispersion divided by SCM length. MAIN OUTCOME MEASURES: SCM thickness and CSA; dye dispersion patterns (dispersion distance and dispersion ratio). RESULTS: SCM thickness and CSA were greatest at the middle injection point (mean ± SD of 6.6 ± 2.0 mm and 1.4 ± 0.6 cm2 , respectively). All injections were successful, except in one case where the SCM was thin and the dye reached the omohyoid muscle. Mean longitudinal dye dispersion and dispersion ratio were significantly greater when the volume was 5 mL. There were no statistically significant differences in dispersion patterns among the three injection points. CONCLUSIONS: Ultrasound-guided intramuscular injection can be performed with good accuracy in the SCM, as ultrasound can be used to evaluate SCM thickness and CSA. Higher volumes of injection solution appear to diffuse better, but further clinical studies are required to determine optimal injection volume.

Optimal Elbow Positions for Identification of the Radial Collateral Ligament Using Ultrasonography.

BACKGROUND: The standard position for examining the lateral elbow with ultrasonography is an "extended" or "slightly flexed" position. However, because the radial collateral ligament (RCL) is more deeply attached on the lateral epicondyle than the common extensor tendon, an anisotropic artifact of the RCL could be observed in the conventional positions, making it difficult to fully visualize the RCL. OBJECTIVES: To determine optimal elbow positions for accurate identification of the RCL and to explore the relevant landmarks in ultrasonography. DESIGN: Prospective study. SETTING: Tertiary university hospital. PARTICIPANTS: Forty healthy elbows of 20 participants. METHODS: The RCL was evaluated using ultrasonography in six elbow flexion positions (0°, 30°, 60°, 90°, 120°, and 140°). The relative depth, defined as the depth of the capitellum subtracted by the depth of the radial head under ultrasonography, was measured at each angle. The rates of successful identification of ultrasonographic landmarks for localizing the RCL were calculated. After ultrasonography, the optimal elbow position for identifying the RCL was determined by group consensus. MAIN OUTCOME MEASUREMENTS: Relative depth between radial head and capitellum, rates of successful identification of ultrasonographic landmarks, and consensus-based determination of the optimal angle. RESULTS: The relative depth significantly decreased with an increase in the flexion angle (P for trend <.001), approaching zero at the angles of 90° and 120°. The rates of successful identification of the superior tubercle, hyperechogenic line, and anterior and posterior tubercles were 100%, 100%, 90%, and 80%, respectively. In the group consensus, the 90° and 120° flexion angles were selected with the highest frequency (90%; 36/40). CONCLUSION: Our findings suggest that elbow flexion at 90° or 120° is optimal for visualization of the RCL with the least possibility of anisotropy under ultrasonography, suggesting that the elbow should be flexed considerably beyond the conventional extended or slightly flexed position.

Radiologic findings for prediction of rehabilitation outcomes in patients with chronic symptomatic os subfibulare.

OBJECTIVE: To retrospectively evaluate the radiologic findings for predicting rehabilitation outcomes in patients with chronic symptomatic os subfibulare. MATERIALS AND METHODS: 38 patients with chronic lateral ankle pain and os subfibulare underwent a standardized rehabilitation program. Rehabilitation outcome was evaluated after ≥3 months of intervention as the following: good response group (n = 20) without the need for further treatment and poor response group (n = 18) who underwent surgery after rehabilitation. Size, shape and location of os subfibulare, anterior talofibular ligament abnormality and attachment to the os subfibulare, interposition of fluid signal intensity between the os subfibulare and the fibula, and bone marrow edema in the os subfibulare on radiographs and MRI were evaluated by two radiologists blinded to rehabilitation outcomes and were compared between the two groups. RESULTS: The mean size of os subfibulare was significantly different between good and poor response groups: 7 versus 12 mm (p < 0.01), respectively. The prevalence of interposition of fluid signal intensity between the os subfibulare and the fibula and bone marrow edema in the os subfibulare on MRI was significantly different between the two groups (p < 0.01). However, other radiologic findings were not significantly different (p ≥ 0.08). The optimal size to classify the two groups was 9 mm with sensitivity of 83.3% and specificity of 80%. Inter-observer reliability was good to excellent (ICC = 0.991 for size and kappa = 0.735-0.923 for others). CONCLUSIONS: MRI may be used to predict rehabilitation outcome in patients with chronic symptomatic os subfibulare.

Electrophysiologic and Ultrasonographic Assessment of Carpal Tunnel Syndrome in Wheelchair Basketball Athletes.

OBJECTIVE: To investigate the contributing factors of carpal tunnel syndrome (CTS), electrodiagnostic and ultrasonographic findings of median nerve, and median nerve change after exercise in wheelchair basketball (WCB) players. METHODS: Fifteen WCB players with manual wheelchairs were enrolled in the study. Medical history of the subjects was taken. Electrodiagnosis and ultrasonography of both median nerves were performed to assess CTS in WCB players. Ultrasonographic median nerves evaluation was conducted after wheelchair propulsion for 20 minutes. RESULTS: Average body mass index (BMI) and period of wheelchair use of CTS subjects were greater than those of normal subjects. Electrodiagnosis revealed CTS in 14 of 30 hands (47%). Cross-sectional area (CSA) of median nerve was greater in CTS subjects than in normal subjects at 0.5 cm and 1 cm proximal to distal wrist crease (DWC), DWC, 1 cm, 2 cm, 3 cm, and 3.5 cm distal to DWC. After exercising, median nerve CSAs at 0.5 cm and 1 cm proximal to DWC, DWC, and 3 cm and 3.5 cm distal to DWC were greater than baseline CSAs in CTS subjects; and median nerve CSAs at 1 cm proximal to DWC and DWC were greater than baseline CSAs in normal subjects. The changes in median nerve CSA after exercise in CTS subjects were greater than in normal subjects at 0.5 cm proximal to DWC and 3 cm and 3.5 cm distal to DWC. CONCLUSION: BMI and total period of wheelchair use contributed to developing CTS in WCB players. The experimental exercise might be related to the median nerve swelling around the inlet and outlet of carpal tunnel in WCB athletes with CTS.

Smoking-Related Renal Histologic Injury in IgA Nephropathy Patients.

PURPOSE: Smoking reportedly exerts deleterious effects on renal function; however, its effects on histology have not been clarified in patients with IgA nephropathy (IgAN). MATERIALS AND METHODS: Renal histology was evaluated in a cohort of 397 patients diagnosed with IgAN according to smoking status and dose in relation to renal function. RESULTS: Among the study cohort, which was predominantly male (88.5%), 52 patients (13%) were current smokers. These current smokers demonstrated more frequent hypertension and higher serum creatinine levels than non/ex-smokers at the time of diagnosis, which was apparent with increased smoking dose. The percentages of global glomerulosclerosis and arteriolar hyalinosis increased with increased smoking dose, whereas tubulointerstitial fibrosis or arterial intimal thickening did not. Glomerular mesangial alpha-smooth muscle actin expression were similar between current and non/ex-smokers matched for age, gender, hypertension, and histologic severity, although the number of glomerular CD68+ cells was significantly fewer in smokers. Initial serum creatinine level, estimated glomerular filtration rate (eGFR), and global glomerulosclerosis were found to be risk factors of serum creatinine doubling in both smokers and non/ex-smokers by univariate analysis during a mean follow-up of 3.8 years. CONCLUSION: In addition to dose dependent renal functional decline and hypertension, smoking contributes to renal disease progression by eliciting microvascular injury in IgAN patients.

Branching patterns of medial and inferior calcaneal nerves around the tarsal tunnel.

OBJECTIVE: To demonstrate the bifurcation pattern of the tibial nerve and its branches. METHODS: Eleven legs of seven fresh cadavers were dissected. The reference line for the bifurcation point of tibial nerve branches was an imaginary horizontal line passing the tip of the medial malleolus. The distances between the reference line and the bifurcation points were measured. The bifurcation branching patterns were categorized as type I, the pattern in which the medial calcaneal nerve (MCN) branched most proximally; type II, the pattern in which the three branches occurred at the same point; and type III, in which MCN branched most distally. RESULTS: There were seven cases (64%) of type I, three cases (27%) of type III, and one case (9%) of type II. The median MCN branching point was 0.2 cm (range, -1 to 3 cm). The median bifurcation points of the lateral plantar nerves and inferior calcaneal nerves was -0.6 cm (range, -1.5 to 1 cm) and -2.5 cm (range, -3.5 to -1 cm), respectively. CONCLUSION: MCN originated from the tibial nerve in most cases, and plantar nerves were bifurcated below the medial malleolus. In all cases, inferior calcaneal nerves originated from the lateral plantar nerve. These anatomical findings could be useful for performing procedures, such as nerve block or electrophysiologic studies.

Enhanced cardiomyogenic differentiation of P19 embryonal carcinoma stem cells.

BACKGROUND AND OBJECTIVES: We investigated the effects of different concentrations of serum, 5-azacytidine, and culture time on the cardiomyogenic differentiation of P19 embryonal carcinoma stem cells in the course of developing an efficient protocol for generating the cardiomyogenic lineage. MATERIALS AND METHODS: P19 cells were plated at a density of 1x10(6) cells on 10-cm bacterial dishes for 96 hours in the presence of 1% dimethyl sulfoxide to form embryoid bodies. The embryoid bodies were cultured in medium with 2% or 10% fetal bovine serum for an additional 10 or 15 consecutive days in the presence of 0, 1, or 3 microM 5-azacytidine. RESULTS: Quantitative real-time polymerase chain reaction (PCR) analysis showed that the messenger ribonucleic acid (mRNA) expression of cardiac muscle-specific genes, such as GATA4, alpha-actin, alpha-myosin heavy chain, and cardiac troponin T, were significantly higher in the 15-day culture groups than in the 10-day culture groups. Furthermore, the cardiac muscle-specific genes were expressed more in the high-serum groups compared to the low-serum groups regardless of the culture time. Cardiomyogenic differentiation of the P19 cells was most effective in 1 microM 5-azacytidine regardless of the serum concentrations. In addition, the stimulation effects of 5-azacytidine on cardiomyogenic differentiation were more significant under low-serum culture conditions compared to high-serum culture conditions. Cardiomyogenic differentiation of P19 cells was further confirmed by immunostaining with cardiac muscle-specific antibodies. CONCLUSION: Taken together, these results demonstrated that cardiomyogenic differentiation of P19 cells was enhanced by a combination of different experimental factors.