Update on Non-invasive Brain Stimulation on Stroke Motor Impairment: A Narrative Review.

Stroke is a leading global cause of death and disability, with motor impairment being one of the common post-stroke complications. Rehabilitation is crucial for functional recovery. Recently, non-invasive brain stimulation (NIBS) has emerged as a promising intervention that allows neuromodulation by activating or inhibiting neural activity in specific brain regions. This narrative review aims to examine current research on the effects of various NIBS techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, vagus nerve stimulation, and transcranial focused ultrasound on post-stroke motor function.

Phase Angle as a Marker of Physical Function in Non-Sarcopenic Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease. Most patients with RA face a barrier to participation in social activities or exercise due to joint pain, despite the beneficial effects of exercise and physical activity. Thus, RA may be a risk factor for sarcopenia in the clinical field. Bioelectrical impedance analysis-derived phase angle (PhA) reflects cellular health and is correlated with the prognosis of various diseases. However, its association with physical function in non-sarcopenic RA female patients remains unclear. We evaluated the association between PhA values and various physical function measures in female patients with non-sarcopenic RA. Methods: Thirty-five participants with RA were screened. One met the criteria for sarcopenia. Finally, 34 patients with non-sarcopenic RA were enrolled. This cross-sectional retrospective study evaluated upper- and lower-extremity strengths, cross-sectional area of rectus femoris, 6 min walking test, Borg scale score, sit-to-stand test, and physical function and mental health from 36-Item Short Form Health Survey scores. Results: In total, 34 female participants (mean age = 49.74 ± 8.15 years) were enrolled. In non-sarcopenic RA patients, PhA was significantly correlated with BMI and ASM/(height)2. Multicollinearity was not detected among the independent variables (VIF < 5). The final multivariable regression model identified ASM/height2 as a significant predictor of PhA among non-sarcopenic RA patients. Conclusion: Multivariable linear regression analyses identified appendicular skeletal muscle mass as a significant predictor of PhA. Bioelectrical impedance analysis-derived PhA is a valuable guidance tool for RA management. PhA can be a useful clinical biomarker of muscle status in non-sarcopenic RA patients.

An Exercise Prescription for Patients with Stroke and Sarcopenia Based on the Modified Delphi Study.

BACKGROUND: We aimed to develop a consensus on the need for and priorities of exercise to treat preexisting sarcopenia with hemiplegic stroke. METHODS: A modified three-round Delphi study was conducted. The panelists responded to the questionnaire on a 7-point Likert scale. Responses were returned with descriptive statistics in the next round. Consensus was defined as >75% agreement (score of 5-7) with a median > 5. The percentage of strong agreement (score of 6-7) and Kendall's coefficient of concordance were calculated to demonstrate a more refined interpretation of the consensus. RESULTS: Fifteen panelists contributed to all rounds. The need for exercise was demonstrated. The consensus was reached on 53 of 58 items in the first round and all items in the second and final rounds. The percentage of strong agreement was high for all but eight items. CONCLUSIONS: This study is the first Delphi study to investigate the need for and priorities of exercise for treating preexisting sarcopenia in stroke hemiplegia. We present a standard recommendation including 57 priorities and a strong recommendation including 49 priorities. The eight items that were excluded reflected factors that are less important to hemiplegic patients with poor balance, cognitive decline, or mental vulnerability.

Post-Stroke Infections: Insights from Big Data Using Clinical Data Warehouse (CDW).

This study analyzed a digitized database of electronic medical records (EMRs) to identify risk factors for post-stroke infections. The sample included 41,236 patients hospitalized with a first stroke diagnosis (ICD-10 codes I60, I61, I63, and I64) between January 2011 and December 2020. Logistic regression analysis was performed to examine the effect of clinical variables on post-stroke infection. Multivariable analysis revealed that post-stroke infection was associated with the male sex (odds ratio [OR]: 1.79; 95% confidence interval [CI]: 1.49-2.15), brain surgery (OR: 7.89; 95% CI: 6.27-9.92), mechanical ventilation (OR: 18.26; 95% CI: 8.49-44.32), enteral tube feeding (OR: 3.65; 95% CI: 2.98-4.47), and functional activity level (modified Barthel index: OR: 0.98; 95% CI: 0.98-0.98). In addition, exposure to steroids (OR: 2.22; 95% CI: 1.60-3.06) and acid-suppressant drugs (OR: 1.44; 95% CI: 1.15-1.81) increased the risk of infection. On the basis of the findings from this multicenter study, it is crucial to carefully evaluate the balance between the potential benefits of acid-suppressant drugs or corticosteroids and the increased risk of infection in patients at high risk for post-stroke infection.

Investigating the Impact of Voice Impairment on Quality of Life in Stroke Patients: The Voice Handicap Index (VHI) Questionnaire Study.

The Voice Handicap Index (VHI) is a patient-centered evaluation tool specifically designed for assessing voice-related quality of life. Although the VHI has been extensively used in patients with voice disorders, its applicability in stroke patients has not been fully established. This prospective cross-sectional study aimed to investigate the feasibility of using the VHI questionnaire in identifying stroke patients with voice problems. The study included a cohort of acute to subacute first-ever stroke patients (n = 48), with or without voice problems, as well as other non-stroke patients (n = 31) who agreed to complete the VHI questionnaire. Stroke patients with self-reported voice problems demonstrated significantly higher VHI scores and poorer life quality scores compared to the control groups. These patients also had lower Mini-Mental State Examination (MMSE), Modified Barthel Index (MBI), and Euro-QoL-5D-5L (EQ-5D-5L) scores. Spearman correlation analysis revealed an inverse association between VHI scores and EQ-5D-5L (rho = -0.77, p < 0.001), Korean Mann Assessment of Swallowing Ability (rho = -0.51, p < 0.001), and other functional parameters, including the National Institutes of Health Stroke Scale, MMSE, and MBI scores. Multiple regression analysis indicated that the VHI score was the biggest contributing factor to EQ scores. This is the first study to demonstrate that stroke patients with voice problems may experience reduced quality of life, even after controlling for other confounding factors such as dysphagia or neurological deficits. Future studies are needed whether addressing these issues by implementing the VHI may facilitate the improvement of patients' quality of life.

Natural course of fat necrosis after deep inferior epigastric perforator flap-based breast reconstruction: Evaluation based on ultrasound examination.

BACKGROUND: Fat necrosis, often developing following deep inferior epigastric perforator (DIEP) flap-based breast reconstruction, is not a negligible complication. This study aimed to conduct a longitudinal assessment of the clinical course of fat necrosis in breast reconstruction with DIEP flap. METHODS: Among patients undergoing immediate DIEP flap-based breast reconstruction between 2009 and 2017, those who developed fat necrosis on ultrasonographic examination and did not undergo surgical intervention for the lesion were reviewed. Changes in lesion size over time were assessed based on regular ultrasound examinations. RESULTS: A total of 37 cases were analyzed, with a mean follow-up of 52.6 months (range, 19-114). Their mean age was 45.8 years, and the mean body mass index was 23.4 kg/m2 . Of these, 21 lesions had disappeared over time. The mean time from detection to the disappearance was 30.4 months. The remaining 16 lesions did not disappear and persisted for a median follow-up of 43.5 months. Compared with the lesions that persisted, those that disappeared were significantly smaller in initial size (p = 0.040) and had a lower inset ratio of the harvested flap (p = 0.006). The optimal cutoff value for the initial size for disappearance was ≤1.97 cm. Among the lesions >1.97 cm in size, 6 (35.3%) of 17 lesions disappeared, whereas in those ≤1.97 cm, 15 (75.0%) of 20 disappeared over time, with a significant difference (p = 0.041). CONCLUSION: The natural course of fat necrosis that develops following the DIEP flap may differ according to its initial size.

Cadaveric Study of Thread Carpal Tunnel Release Using Newly Developed Thread, With a Histologic Perspective.

OBJECTIVE: To examine the usefulness and feasibility of modified thread carpal tunnel release (TCTR) by comparing the results of using pre-existing commercial thread with those of a newly developed thread (Smartwire-01). METHODS: A total of 17 cadaveric wrists were used in the study. The modified TCTR method was practiced by two different experts. Pre-existing commercial surgical dissecting thread (Loop&ShearTM) was used for five wrists and the newly developed Smartwire-01 was used for twelve wrists. The gross and microanatomy of the specimens were evaluated by a blinded anatomist. RESULTS: Both types of thread were able to cut the TCL similarly. Gross anatomy and histologic findings showed that there was no significant difference between the two types of threads. However, the practitioners felt that it was easier to cut the TCL using the newly-developed thread. CONCLUSION: TCTR using Smartwire-01 was as effective as pre-existing Loop&ShearTM, with better user experiences.

Three-dimensional Volume Changes of the Reconstructed Breast Following DIEP Flap Breast Reconstruction.

BACKGROUND: This study aimed to assess whether the reconstructed breast volume changed postoperatively following a deep inferior epigastric artery perforator (DIEP) flap. METHODS: Patients were included if they had undergone unilateral breast reconstruction with a DIEP flap at the two selected centers between April 2017 and September 2019. Serial 3-D surface imaging of both breasts was taken at 1, 3, 6, and 12 months postoperatively. The primary outcome was a volume ratio of the reconstructed to the contralateral breast. A linear mixed-effect model was used to evaluate whether the DIEP flap volume changed according to the postoperative time. RESULTS: A total of 74 patients were included in the analysis. The mean volume ratio of the reconstructed side compared with the contralateral breast at 1, 3, 6, and 12 months postoperatively were 106.9%, 105.9%, 108.7%, and 107.6%, respectively. In the linear mixed effect model, the volume ratio of the reconstructed breast did not change over time for immediate reconstructions (p = 0.376). However, there was an increase over time in delayed reconstructions (p = 0.043). Adjuvant radiation, chemotherapy, and hormone therapy did not influence the volume ratio of the reconstruced breast. Correlation analysis using repeatedly measured values showed that both reconstruced and healthy breast volumes had positive correlation with the patient's body weight (p < 0.001). On the other hand, volume ratio of the breasts was not influenced by the patient's body weight (p = 0.493). The volume ratio of the reconstructed breast significantly decreased in the upper inner (p = 0.003) and the upper outer (p = 0.006) quadrants, while increasing in the lower outer (p = 0.002) quadrant throughout the first-year postoperative period. CONCLUSION: The volume ratio of the reconstructed to the contralateral breast does not decrease postoperatively following DIEP flap breast reconstruction.

Real-Time Interactive Digital Health Care System for Postoperative Breast Cancer Patients: A Randomized Controlled Trial.

Introduction: Limited range of motion (ROM) of the shoulder occurs commonly after breast cancer surgery, resulting in reduced quality of life and difficulty with activities of daily living. Physical exercise is effective in postoperative breast cancer patients, but no study has assessed the effects of augmented reality (AR)-based telerehabilitation. Therefore, this study aimed to investigate the effect of hospital-home linked rehabilitation therapy using an AR-based digital health care system (UINCARE Home+) in postoperative patients with breast cancer. Methods: This study was a prospective, multicenter, assessor-blinded, randomized controlled trial. Patients who underwent breast cancer surgery were assigned to either the UINCARE Home+ (intervention) group or the brochure-based home rehabilitation (control) group for an 8-week intervention. The study outcomes were the change in ROM of the affected shoulder, pain in the affected shoulder (Numerical Rating Scale [NRS]), functional outcomes (Disabilities of the Arm, Shoulder, and Hand questionnaire [QuickDASH] score), and quality of life (Functional Assessment of Cancer Therapy-Breast [FACT-B] and EuroQoL 5-Dimension 5-Level [EQ-5D-5L] scores), all of which were measured at enrollment and at 4, 8, and 12 weeks thereafter. Results: A total of 100 participants were enrolled in the study (n = 50 in each groups). In both groups, active and passive ROM, NRS, and the QuickDASH, FACT-B, and EQ-5D-5L scores showed significant improvements from baseline to 12 weeks (p < 0.001), but no group differences were detected. Discussion: A home-based exercise program with an AR system improved shoulder dysfunction in breast cancer patients and could be used in conjunction with a traditional hospital-based rehabilitation program. Trial Registration: ClinicalTrials.gov ID: NCT04316156.

The effect of breast cancer surgery on spine alignment: Whole-spine radiograph analysis.

Breast cancer survivors may experience spinal deformity following breast cancer surgery. This study investigated the long-term effects of breast cancer surgery on whole-spine alignment. This retrospective study included 200 patients who underwent breast cancer surgery and ≥2 anteroposterior standing whole-spine X-rays. The curvature of the spine was measured using the Cobb angle; changes in Cobb angle between X-rays were compared among three groups according to breast cancer surgery type. The mean interval between initial and follow-up X-ray was 28.46 ± 13.39 months. The change in Cobb angle was 0.40 ± 1.65 degrees and the absolute value of that change was 1.25 ± 1.15 degrees in all patients with breast cancer. There were no significant differences in angular change among groups according to breast cancer surgery type. Most patients showed minimal changes in spinal alignment after breast cancer surgery. Our findings indicate that breast cancer surgery does not negatively affect spinal alignment.

A clinical study of thread carpal tunnel release with a newly developed thread: A retrospective pilot study.

INTRODUCTION: Previous studies have shown that, thread carpal tunnel release (TCTR), an ultrasound-guided transverse carpal ligament (TCL) transection procedure through needle and thread, to be a safe and effective technique for carpal tunnel release, compared to an open and endoscopic technique. We developed a newly improved thread (Smartwire-01, 0.27mm in diameter, Korea). This pilot study was performed to propose the effectiveness of TCTR with Smartwire-01 compared to the commercial thread in clinical settings. METHODS: A total of 22 TCTR procedures have been performed on 19 patients by one physiatrist during a 42-month period. The diagnosis of carpal tunnel syndrome was based on standard clinical criteria including electromyography (EMG). Patients were divided into two groups, one dissected with commercial thread and the other with Smartwire-01. The technique was standardized by keeping the entry point at the middle of the palm and the exit point at just medial to the palmaris longus tendon. The Numeric Rating Scale and Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) were used to assess monthly outcomes for 6 months following the procedure. The Wilcoxon signed rank test and the Mann-Whitney-U test were performed to analyze the above variables in the two groups. RESULTS: There was no definite evidence that the two groups have significant differences for any of the surveyed variables. The TCTR procedure with our newly developed thread also had significant improvements for all variables, showing its effectiveness in both pain and functional ability. The NRS and BCTQ severity and functional scales showed significant decreases just after the dissection and progressive improvement during each monthly follow-up of our study until the last assessment at 6 months. CONCLUSION: The study suggests that, our newly developed thread is as safe and effective as the commercial thread in TCTR, we therefore recommend a randomize controlled trial with above methodology.

Post-stroke respiratory complications using machine learning with voice features from mobile devices.

Abnormal voice may identify those at risk of post-stroke aspiration. This study was aimed to determine whether machine learning algorithms with voice recorded via a mobile device can accurately classify those with dysphagia at risk of tube feeding and post-stroke aspiration pneumonia and be used as digital biomarkers. Voice samples from patients referred for swallowing disturbance in a university-affiliated hospital were collected prospectively using a mobile device. Subjects that required tube feeding were further classified to high risk of respiratory complication, based on the voluntary cough strength and abnormal chest x-ray images. A total of 449 samples were obtained, with 234 requiring tube feeding and 113 showing high risk of respiratory complications. The eXtreme gradient boosting multimodal models that included abnormal acoustic features and clinical variables showed high sensitivity levels of 88.7% (95% CI 82.6-94.7) and 84.5% (95% CI 76.9-92.1) in the classification of those at risk of tube feeding and at high risk of respiratory complications; respectively. In both cases, voice features proved to be the strongest contributing factors in these models. Voice features may be considered as viable digital biomarkers in those at risk of respiratory complications related to post-stroke dysphagia.

Single Nucleotide Polymorphisms May Increase the Risk of Aspiration Pneumonia in Post-Stroke Patients with Dysphagia.

This study aimed to evaluate whether genetic polymorphism is associated with an increased risk of infection, specifically post-stroke aspiration pneumonia. Blood samples were obtained from a total of 206 post-stroke participants (males, n = 136; mean age, 63.8 years). Genotyping was performed for catechol-O-methyltransferase (rs4680, rs165599), dopamine receptors (DRD1; rs4532, DRD2; rs1800497, DRD3; rs6280), brain-derived neurotrophic factor (rs6265), apolipoprotein E (rs429358, rs7412), and the interleukin-1 receptor antagonist gene (rs4251961). The subjects were stratified into two groups, aged < 65 (young) and ≥ 65 (elderly). Functional parameters and swallowing outcomes were measured at enrollment and at 3 months post-onset. The primary outcome was the incidence of aspiration pneumonia. Analysis of the association between genetic polymorphisms and aspiration pneumonia history showed that a minor C rs429358 allele was associated with the occurrence of aspiration pneumonia in the young group, both in the additive and the dominant models (odds ratio: 4.53; 95% CI: 1.60−12.84, p = 0.004). In the multivariable analysis, the minor C rs429358 allele increased the risk of post-stroke aspiration pneumonia in young stroke patients by 5.35 (95% CI: 1.64−20.88). In contrast, no such association was observed in the elderly group. Apolipoprotein E polymorphism may affect the risk of post-stroke aspiration pneumonia.

Preservation of Cerebellar Afferent Pathway May Be Related to Good Hand Function in Patients with Stroke.

Many chronic stroke patients suffer from worsened hand function, and functional recovery of the hand does not occur well after six months of stroke. Therefore, predicting final hand function after stroke through acute phase imaging would be an important issue in counseling with the patients or their family. Thus, we investigated the remaining white matter integrity in the corticospinal tract (CST) and cortico-ponto-cerebellar tract (CPCT) at the acute stage of stroke and chronic hand function after stroke, and present the cut-off value of fiber number (FN) and fractional anisotropy (FA) of CST and CPCT at the acute stage for predicting final hand function after the recovery period. This retrospective case-control study included 18 stroke patients who were classified into two groups: poor hand function with stroke (n = 11) and good hand function with stroke (n = 7). DTI was done within two months ± 15 days after onset, and the Jebson's Hand Function test was conducted 6-12 months after onset. The investigation of white matter was focused on the values of FN and FA for CST and CPCT, which were measured separately. The normalized (affected/non-affected) FA and FN values in the CPCT in the good hand function group were higher than those in the poor hand function group. The normalized FN and FA values in the CST were not significantly different between the poor hand function group and the good hand function group. The normalized cut-off value that distinguished the good hand function group from the poor hand function group was 0.8889 for FA in the CPCT. The integrity of the CPCT in the acute stage was associated with hand function in the chronic stage after a stroke. Ultimately, the integrity of the CPCT in the early stage after onset can be used to predict chronic hand function. Based on these results, cerebellar afferent fiber measurements may be a useful addition to predict hand function and plan specific rehabilitation strategies in stroke patients.

Bioimpedance phase angle and sarcopenia in older patients with prostate cancer.

AIM: The purpose of this study was to evaluate the factors associated with the bioimpedance phase angle (PhA) in older patients with prostate cancer, and to determine the optimal cutoff for the PhA in patients with sarcopenia and prostate cancer. METHODS: This retrospective cross-sectional analysis enrolled patients with prostate cancer aged ≥60 years. Appendicular skeletal muscle mass and PhA estimated by bioimpedance analysis, grip strength, the five-time chair stand test, gait speed, the Short Physical Performance Battery, the 2-min walk test and the International Physical Activity Questionnaire Short Form were obtained at enrollment. The diagnosis of sarcopenia was based on the 2019 consensus of the Asian Working Group for Sarcopenia. RESULTS: In total, 119 male participants (mean age = 70.7 ± 6.1 years) were available for analysis. A multivariable linear regression model revealed that age, body mass index and the maximal grip strength value were associated with the PhA. The area under the receiver operating characteristic curve value of the PhA for sarcopenia diagnosis was 0.77 (95% confidence interval 0.64-0.90, P < 0.001), with a PhA cutoff value of 4.87°. CONCLUSIONS: PhA estimated by bioimpedance analysis may be utilized as useful clinical biomarker for reflecting muscle strength and sarcopenia in older patients with prostate cancer. Geriatr Gerontol Int 2022; 22: 623-627.

Neural correlates in the development of and recovery from dysphagia after supratentorial stroke: A prospective tractography study.

BACKGROUND: Swallowing impairment after stroke may be related to the state of the corticobulbar tract (CBT), which is the motor projection fiber responsible for deglutition, but evidence is still lacking regarding which parameter could relate to poststroke swallowing recovery as measured by videofluroscope findings. This prospective study evaluated diffusion tensor imaging (DTI) parameters among dysphagic stroke patients compared with those of nondysphagia stroke patients and age-matched healthy subjects and followed swallowing recovery in dysphagic patients as assessed with the Modified Barium Swallow Impairment Profile (MBSImP©). METHODS: Diffusion tractography was performed in 69 subjects, consisting of 27 S patients with dysphagia, 18 healthy subjects and 24 S patients with no evidence of dysphagia. DTI was performed within 14 days of stroke onset. Follow-up DTI was performed in the dysphagic group at three months. The tract volume (TV) of the CBT and frontal operculum as determined by fractional anisotropy (FA) was compared among the 3 groups. Correlations of these parameters with initial dysphagia severity and swallowing parameters at baseline and 3 months postonset were assessed. RESULTS: All stroke patients showed lower CBT TV on the affected and unaffected sides than those in the control group, even in those who showed no evidence of clinical dysphagia. The dysphagia group showed a greater reduction in CBT TV on the affected side (P < 0.001). Receiver operating characteristic analysis showed that cutoff values of 4.1 cm3 for TV and 0.24 for FA from the affected side could classify dysphagia with good accuracy (AUC = 0.77, 0.75, respectively) and specificity levels. FA values in the unaffected frontal operculum showed a significant correlation (rho = -0.40, P = 0.02) with swallowing outcome as observed by the total scores of MBSImP©. In addition, these values proved to be significant variables to predict swallowing outcome in multiple regression analysis (R2 = 0.6317, adjR2 = 0.5815, F = 12.58, p < 0.001, AIC = 203.65). CONCLUSIONS: Even when clinical dysphagia is not apparent, individuals with a supratentorial stroke may show reduced CBT parameters compared to healthy controls. Supratentorial stroke may manifest with dysphagia if a certain extent of CBT volume and white matter tract integrity is involved, with a greater degree of CBT injury in the affected sides determining poststroke dysphagia severity. In contrast, recovery was independent of the affected parameters, and an initial lower FA value in the unaffected frontal operculum was indicative of a poorer 3-month dysphagia outcome. DTI parameters obtained within two weeks of stroke onset may help classify those with dysphagia, predict recovery and help plain therapeutic strategies to maintain the adaptive role of the white matter tract, which is crucial in swallowing recovery.

Role of Catechol-O-methyltransferase Val158Met Polymorphism on Transcranial Direct Current Stimulation in Swallowing.

Transcranial direct current stimulation (tDCS) is one of the latest post-stroke dysphagia treatment modalities, and the effect of tDCS is known to be affected by various factors including genetic polymorphisms. However, the role of catechol-O-methyltransferase (COMT) polymorphisms on tDCS in swallowing is unclear. In this prospective pilot study, we aim to explore the effect of tDCS on the swallowing cortex and subsequent swallowing motor function according to COMT polymorphism. Twenty-four healthy participants received either anodal tDCS or sham mode tDCS on the mylohyoid motor cortex at random order, after inhibitory repetitive transcranial magnetic stimulation (rTMS) for preconditioning. The primary outcome was the changes of mylohyoid-motor-evoked potentials (MH-MEP) amplitude in each COMT polymorphism group, from the post-inhibitory rTMS baseline state to immediate, 30, and 60 min after tDCS. The secondary outcomes were the changes in swallowing function. The results showed that COMT Val/Val polymorphism showed improvement across time in the MH-MEP amplitudes and triggering time of swallowing after tDCS, whereas COMT Met carrier group did not show significant changes of MH-MEP or swallowing function across time. This therapeutic response variability of tDCS in the mylohyoid motor system according to COMT polymorphism support the importance of genetic analysis in individualized dysphagia treatment.

A Cadaveric Study of Thread Cubital Tunnel Release with Newly Developed Threads.

OBJECTIVE: The percutaneous thread transection technique is a surgical dissecting method using a dissecting thread inserted through a needle under ultrasound guidance without skin incision. As the new dissecting threads were developed domestically, this cadaver study was conducted to compare the effectiveness and safety between the new threads (ultra V sswire and smartwire-01) and a pre-existing commercial dissecting thread (loop & shear) by demonstrating a modified looped thread cubital tunnel release. METHODS: The percutaneous cubital tunnel release procedure was performed on 29 fresh cadaveric upper extremities. The preexisting commercial thread was used in 5 upper extremities. The two newly developed threads were used in 24 upper extremities. Two practitioners performed the procedures separately. After the modified looped thread cubital release, anatomical and histological analyses were performed by a blinded anatomist. The presence of the dissected cubital tunnel and damaged adjacent soft tissue was assessed. RESULTS: Out of the 29 cadaveric upper extremities, 27 specimens showed complete dissection of the Osborne ligament and the proximal fascia of the flexor carpi ulnaris muscle. One specimen was incompletely dissected in each of the ultra V sswire and smartwire-01 groups. There were no injuries of adjacent structures including the ulnar nerve, ulnar artery, medial antebrachial cutaneous nerve, or flexor tendon with either the commercial thread or the newly developed threads. The anatomical analysis revealed clear and sharp incisional margins of the cubital tunnel in the Smartwire-01 and loop & shear groups. All three kinds of threads maintained proper linear elasticity for easy handling during the procedure. The smartwire-01 provided higher visibility in ultrasound than the other threads. CONCLUSION: The newly developed threads were effective and safe for use in the thread cubital tunnel release procedure.