Clinical validation of automated depth camera-based measurement of the Fugl-Meyer assessment for upper extremity.

OBJECTIVE: Depth camera-based measurement has demonstrated efficacy in automated assessment of upper limb Fugl-Meyer Assessment for paralysis rehabilitation. However, there is a lack of adequately sized studies to provide clinical support. Thus, we developed an automated system utilizing depth camera and machine learning, and assessed its feasibility and validity in a clinical setting. DESIGN: Validation and feasibility study of a measurement instrument based on single cross-sectional data. SETTING: Rehabilitation unit in a general hospital. PARTICIPANTS: Ninety-five patients with hemiparesis admitted for inpatient rehabilitation unit (2021-2023). MAIN MEASURES: Scores for each item, excluding those related to reflexes, were computed utilizing machine learning models trained on participant videos and readouts from force test devices, while the remaining reflex scores were derived through regression algorithms. Concurrent criterion validity was evaluated using sensitivity, specificity, percent agreement and Cohen's Kappa coefficient for ordinal scores of individual items, as well as correlations and intraclass correlation coefficients for total scores. Video-based manual assessment was also conducted and compared to the automated tools. RESULT: The majority of patients completed the assessment without therapist intervention. The automated scoring models demonstrated superior validity compared to video-based manual assessment across most items. The total scores derived from the automated assessment exhibited a high coefficient of 0.960. However, the validity of force test items utilizing force sensing resistors was relatively low. CONCLUSION: The integration of depth camera technology and machine learning models for automated Fugl-Meyer Assessment demonstrated acceptable validity and feasibility, suggesting its potential as a valuable tool in rehabilitation assessment.

Effect of inactivated COVID-19 vaccine on the negative conversion of nucleic acid in asymptomatic or mild patients with COVID-19.

BACKGROUND: Negative conversion of nucleic acid was a key factor in deciding discharge or the end of isolation of asymptomatic or mild COVID-19 patients. We aimed to explore the effect of vaccination on the time to negative conversion after Omicron infection. METHODS: This retrospective cohort study included asymptomatic or mild patients with COVID-19 admitted to Fangcang shelter Hospital from November 10, 2022 to December 2, 2022. The relationship between vaccination status and the time to negative conversion was analyzed by multiple linear regression. RESULTS: A total of 2,104 asymptomatic or mild COVID-19 patients were included in the analysis, of whom 1,963 were vaccinated. The mean time to negative conversion of no vaccination, one dose, two doses, and three doses were 12.57 (5.05), 12.18 (3.46), 11.67 (4.86) and 11.22 (4.02) days, respectively (p = 0.002). Compared with no vaccination, two doses (ß=-0.88, 95% CI: -1.74, -0.02, p = 0.045), and three doses (ß=-1.51, 95% CI: -2.33, -0.70, p < 0.001) were both associated with shorter time to negative conversion. Comparing with two doses, booster dose was associated significantly with shorter time to negative conversion (ß=-0.63, 95% CI: -1.07, -0.20, p = 0.004). Age was positively correlated with the time to negative conversion (ß = 0.04, 95% CI: 0.02, 0.05, p < 0.001). CONCLUSION: Vaccination with inactivated vaccine and booster dose can shorten the time to negative conversion of asymptomatic or mild COVID-19 patients. The significant prolongation of time to negative conversion with increasing age suggests the promotion of vaccination, especially booster dose, particularly in the elderly.

Reliability of a human pose tracking algorithm for measuring upper limb joints: comparison with photography-based goniometry.

BACKGROUND: Range of motion (ROM) measurements are essential for diagnosing and evaluating upper extremity conditions. Clinical goniometry is the most commonly used methods but it is time-consuming and skill-demanding. Recent advances in human tracking algorithm suggest potential for automatic angle measuring from RGB images. It provides an attractive alternative for at-distance measuring. However, the reliability of this method has not been fully established. The purpose of this study is to evaluate if the results of algorithm are as reliable as human raters in upper limb movements. METHODS: Thirty healthy young adults (20 males, 10 females) participated in this study. Participants were asked to performed a 6-motion task including movement of shoulder, elbow and wrist. Images of movements were captured by commercial digital cameras. Each movement was measured by a pose tracking algorithm (OpenPose) and compared with the surgeon-measurement results. The mean differences between the two measurements were compared. Pearson correlation coefficients were used to determine the relationship. Reliability was investigated by the intra-class correlation coefficients. RESULTS: Comparing this algorithm-based method with manual measurement, the mean differences were less than 3 degrees in 5 motions (shoulder abduction: 0.51; shoulder elevation: 2.87; elbow flexion:0.38; elbow extension:0.65; wrist extension: 0.78) except wrist flexion. All the intra-class correlation coefficients were larger than 0.60. The Pearson coefficients also showed high correlations between the two measurements (p < 0.001). CONCLUSIONS: Our results indicated that pose estimation is a reliable method to measure the shoulder and elbow angles, supporting RGB images for measuring joint ROM. Our results presented the possibility that patients can assess their ROM by photos taken by a digital camera. TRIAL REGISTRATION: This study was registered in the Clinical Trials Center of The First Affiliated Hospital, Sun Yat-sen University (2021-387).

Thiol-Rich Multifunctional Macromolecular Crosslinker for Gelatin-Norbornene-Based Bioprinting.

Extrusion-based bioprinting is an emerging and most frequently used technique for the fabrication of cell-laden constructs. A suitable hydrogel-based bioink for cell encapsulation and protection is critical for printability, structural stability, and post-printing cell viability. The thiol-ene chemistry-based gelatin-norbornene (GelNB) hydrogels have drawn much attention as a promising substitution of gelatin methacryloyl (GelMA), owing to the fast and controllable step-growth polymerization mechanism, as well as a significant reduction in reactive oxygen species (ROS) accumulation. Herein, thiolated heparin (HepSH) was synthesized and used as a macromolecular crosslinker for GelNB-based bioprinting, so that GelNB gelation became less sensitive to the thiol/ene ratio. The mechanical stability and moduli of GelNB/HepSH hydrogels were easily manipulated by the concentration and/or degree of thiol substitution. The GelNB/HepSH hydrogel allowed little intracellular ROS for encapsulated cells but provided vascular endothelial growth factor binding affinity for potential facilitation of neovascularization. Finally, the GelNB/HepSH bioink enabled a convenient printing process for both complex-structured bioscaffolds and cell-laden constructs, and resulted in good printability and high post-crosslinking cell viability. The crosslinker HepSH may serve as a multifunctional macromolecule that enables GelNB-based bioprinting in broad applications in regenerative medicine.

Revisiting the Blood Supply of the Rectus Femoris: A Case Report and Computed Tomography Angiography Study.

BACKGROUND: Rectus femoris necrosis is a rare but severe complication after anterolateral thigh flap (ALTF) harvesting. It has been previously reported that the blood supply of the rectus femoris (RF) often arises from the same source artery as the ALTF; however, precise descriptions of the relationship remain limited. This article revisits the blood supply of the RF based on computed tomography angiography (CTA) and analyzes the possible influence of the blood supply on the RF during ALTF harvesting. METHODS: Between December 2017 and June 2018, CTA images of the bilateral lower extremities of 25 patients were studied. The RF length, number, and diameter of branches at the entry point into muscle, location, and overall branch vessel origins were recorded. RESULTS: The average ± SD RF length was 384.73 ± 19.28 mm. There were 170 branches (mean ± SD, 3.4 ± 0.96 branches per thigh), mainly arising from the lateral circumflex femoral artery. The average ± SD diameter was 1.90 ± 0.51 mm. The first branch was located at 1/5 of the proximal site of the RF, and 91% of all branches were located above the midpoint. The RF vascularity can be classified into 2 types: type 1 (36% of sides) has branches that arise from a single artery (descending lateral circumflex femoral artery or femoral artery), whereas type 2 (64% of sides) has branches at the 1/5 proximal and 4/5 distal parts, which arise from different arteries. CONCLUSIONS: Preoperative CTA can provide anatomic information about the RF's nutrient vessel(s) and helps to optimize ALTF design.

Miconazole enhances nerve regeneration and functional recovery after sciatic nerve crush injury.

INTRODUCTION: Improving axonal outgrowth and remyelination is crucial for peripheral nerve regeneration. Miconazole appears to enhance remyelination in the central nervous system. In this study we assess the effect of miconazole on axonal regeneration using a sciatic nerve crush injury model in rats. METHODS: Fifty Sprague-Dawley rats were divided into control and miconazole groups. Nerve regeneration and myelination were determined using histological and electrophysiological assessment. Evaluation of sensory and motor recovery was performed using the pinprick assay and sciatic functional index. The Cell Counting Kit-8 assay and Western blotting were used to assess the proliferation and neurotrophic expression of RSC 96 Schwann cells. RESULTS: Miconazole promoted axonal regrowth, increased myelinated nerve fibers, improved sensory recovery and walking behavior, enhanced stimulated amplitude and nerve conduction velocity, and elevated proliferation and neurotrophic expression of RSC 96 Schwann cells. DISCUSSION: Miconazole was beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Muscle Nerve 57: 821-828, 2018.

Microanatomy of the Separable Length of the C7.

OBJECTIVE: The objective of this study was to provide anatomical data on modified contralateral C7 (cC7) nerve root transfers by dissecting and measuring the separable lengths of the C7 root, trunk, and divisions. MATERIALS AND METHODS: Fifteen adult cervicothoracic specimens were dissected and measured using Vernier calipers after exposing the brachial plexus. Measurements included the length of the C7 from the root to the trunk, the lengths of the C7 root-trunk-anterior division (and posterior division). The epineuria at the C7 root-division-cord junctions were opened until the internal nerve bundles fused together and could not be separated by microdissection. The lengths of the C7 root-trunk-anterior (and posterior) division were measured again after microdissection. The lengths of cC7 nerve of 20 patients with bracial plexus avulsion were measured using the former technique. RESULTS: The length of the C7 root-trunk was 45.87 SD 10.43 mm. Before separation, the lengths of the C7 root-trunk-anterior division and the root-trunk-posterior division were 61.14 SD 13.44 and 54.63 SD 11.35 mm, respectively; after separation, the lengths were 74.67 SD 12.86 and 68.73 SD 11.86 mm, respectively. The prolonged lengths were 13.15 SD 4.26 and 14.21 SD 6.98 mm, respectively. The prolonged lengths were significantly greater (p < 0.05). The prolonged length of C7 nerve clinically was anterior division, 15.30 SD 3.76 mm and posterior division, 11.10 SD 3.01 mm. CONCLUSION: The C7 division lengths can be prolonged by dissecting the epineuria at the division-cord junction of the C7 nerve root.

Ginkgo biloba extract (EGb 761) promotes peripheral nerve regeneration and neovascularization after acellular nerve allografts in a rat model.

This study aimed to investigate whether or not ginkgo biloba extract (EGb 761) enhances peripheral nerve regeneration and vascularization after repair using acellular nerve allografts (ANA). Seventy-two Sprague-Dawley rats were randomly divided into three experimental groups: a unilateral 15-mm sciatic nerve defect was created and repaired with an autologous graft (autograft group); the same defect was repaired with an 18 mm ANA with an i.p. injection of normal saline for 10 days (saline group); and in the final group, the same defect was repaired with an 18 mm ANA with an i.p. injection of EGb 761 for 10 days (EGb 761 group). Axon outgrowth and vascularization were evaluated by immunocytochemistry 14 days post-implantation. The expression of genes associated with angiogenesis was analyzed by real-time polymerase chain reaction (PCR) seven days post-implantation. Compared with the saline group, rats in the EGb 761 group significantly increased the number of myelinated fibers and the average diameter of the nerves within the graft. There is no significant difference between the EGb 761 group and the autograft group. The expression of CD34 and NF200 was significantly higher in the EGb 761 group than in the saline group. Additionally, EGb 761 treatment increased the expression of several angiogenesis-related genes, including Vegf, SOX18, Prom 1, and IL-6. In conclusion, ANA repair with EGb 761 treatment demonstrates effects on peripheral nerve regeneration and vascularization that are equal to those of autologous graft repair, and that are superior to ANA repair alone.

Modified classification and repair of perineal soft tissue injuries associated with open pelvic fractures.

BACKGROUND: This study describes a modified classification and management protocol for perineal soft tissue injuries associated with pelvic fractures. METHODS: A total of 11 patients with perineal soft tissue injuries associated with open pelvic fractures were studied retrospectively. The patients were classified into three types based on the area of defect: type A (urogenital zone), type B (anal zone), and type C (both urogenital and anal zones). Each type included the following subclasses: A1 (without urethra injuries), A2 (with urethra injuries), B1 (without anorectal injuries), B2 (with anorectal injuries), C1 (with types A1 and B1), C2 (with types A2 and B1), C3 (with types A1 and B2), and C4 (with types A2 and B2). The management protocol was planned according to the individual classifications. Protocol A1 (for type A1) involved skin graft or myocutaneous flap transplantation. Protocol A2 (for type A2) involved the same protocol combined with urine diversion. Protocol B1 (for type B1) involved skin graft or myocutaneous flap transplantation. Protocol B2 (for type B2) involved the same management combined with fecal diversion. Protocol C involved the correspondent protocol used for each subtype of type C. RESULTS: Out of the 11 patients, there were 5, 3, and 3 cases of types A, B, and C, respectively. One patient died due to sepsis, and the wounds of the remaining patients healed well. No anal incontinence had occurred. CONCLUSIONS: Perineal soft tissue injuries associated with pelvic fractures can be classified into three types, and the management protocol can be planned according to the classification.

A Meta-Analysis for Postoperative Complications in Tibial Plafond Fracture: Open Reduction and Internal Fixation Versus Limited Internal Fixation Combined With External Fixator.

The treatment of tibial plafond fractures is challenging to foot and ankle surgeons. Open reduction and internal fixation and limited internal fixation combined with an external fixator are 2 of the most commonly used methods of tibial plafond fracture repair. However, conclusions regarding the superior choice remain controversial. The present meta-analysis aimed to quantitatively compare the postoperative complications between open reduction and internal fixation and limited internal fixation combined with an external fixator for tibial plafond fractures. Nine studies with 498 fractures in 494 patients were included in the present study. The meta-analysis found no significant differences in bone healing complications (risk ratio [RR] 1.17, 95% confidence interval [CI] 0.68 to 2.01, p = .58], nonunion (RR 1.09, 95% CI 0.51 to 2.36, p = .82), malunion or delayed union (RR 1.24, 95% CI 0.57 to 2.69, p = .59), superficial (RR 1.56, 95% CI 0.43 to 5.61, p = .50) and deep (RR 1.89, 95% CI 0.62 to 5.80) infections, arthritis symptoms (RR 1.20, 95% CI 0.92 to 1.58, p = .18), or chronic osteomyelitis (RR 0.31, 95% CI 0.05 to 1.84, p = .20) between the 2 groups.

Etifoxine provides benefits in nerve repair with acellular nerve grafts.

INTRODUCTION: Acellular nerve grafts are good candidates for nerve repair, but the clinical outcome of grafting is not always satisfactory. We investigated whether etifoxine could enhance nerve regeneration. METHODS: Seventy-two Sprague-Dawley rats were divided into 3 groups: (1) autograft; (2) acellular nerve graft; and (3) acellular nerve graft plus etifoxine. Histological and electrophysiological examinations were performed to evaluate the efficacy of nerve regeneration. Walking-track analysis was used to examine functional recovery. Quantitative polymerase chain reaction was used to evaluate changes in mRNA level. RESULTS: Etifoxine: (i) increased expression of neurofilaments in regenerated axons; (ii) improved sciatic nerve regeneration measured by histological examination; (iii) increased nerve conduction velocity; (iv) improved walking behavior as measured by footprint analysis; and (v) boosted expression of neurotrophins. CONCLUSIONS: These results show that etifoxine can enhance peripheral nerve regeneration across large nerve gaps repaired by acellular nerve grafts by increasing expression of neurotrophins.

Modified pathological classification of brachial plexus root injury and its MR imaging characteristics.

The authors described a modified pathological classification (PC) of brachial plexus injury (BPI) and its magnetic resonance (MR) imaging characteristics. The reliability and diagnostic accuracy of MR imaging for detecting nerve injury was discussed. Between 2006 and 2010, 86 patients with BPI were managed surgically in our department. Their preoperative MR images and surgical findings were analyzed retrospectively. The PC of BPI was classified into five types: (I) nerve root injury in continuity (including Sunderland grade I-IV injury); (II) postganglionic spinal nerve rupture with or without proximal stump; (III) preganglionic root injury (visible); (IV) preganglionic nerve root injury and postganglionic spinal nerves injury; (V) preganglionic root injury (invisible). The main MR imaging characteristics of BPI included traumatic meningocele, displacement of spinal cord, the absence of nerve root, "Black line" sign, nerve root/trunk injury in continuity, and thickening and edema of nerve root. The accuracy of MR imaging for detecting C5, C6, C7, C8, and T1 nerve roots injury were 93.3, 95.2, 92.3, 84, and 74.4%, respectively. The modified PC provides a detailed description of nerve root injury in BPI, and MR imaging technique is a reliable method for detecting nerve root injury.

Etifoxine promotes glia-derived neurite outgrowth in vitro and in vivo.

BACKGROUND: Peripheral nerve injuries usually require a graft to facilitate axonal regeneration into the distal nerve stump. Acellular nerve grafts are good candidates for nerve repair, but clinical outcomes from grafts are not always satisfactory. Etifoxine is a ligand of the 18-kDa translocator protein (TSPO) and has been demonstrated to serve multiple functions in nervous system. METHODS: This study aimed to determine the optimal concentration of etifoxine for neurite outgrowth using PC12 cells and verify whether etifoxine could enhance in vivo peripheral nerve regeneration. PC12 cells were exposed to various concentrations of etifoxine (5, 10, 20, and 40 µM). Neuronal-like outgrowth and glia-derived neurotrophic factor (GDNF) mRNA expression were measured, and a rat sciatic nerve transection model was employed. Histological examination was used to evaluate the efficacy of nerve regeneration, and real-time polymerase chain reaction (PCR) evaluated changes in mRNA levels after etifoxine treatment. RESULTS: Our data show that etifoxine increased neuronal-like outgrowth in PC12 cells in a dose-dependent manner; however, GDNF expression peaked at 20 µM etifoxine (1.97-fold increase compared with control, p = 0.0046). In vivo studies demonstrated that etifoxine improved sciatic nerve regeneration, modulated immune responses, and boosted neurotrophin expression. CONCLUSIONS: Because of etifoxine's adverse effects, we suggest an optimal etifoxine concentration of 20 µM. Its beneficial role may lie in increased neurotrophin expression, and etifoxine may be a promising therapeutic for patients with peripheral nerve injuries.

Automatic range of motion measurement via smartphone images for telemedicine examination of the hand.

BACKGROUND: Telemedicine support virtual consultations and evaluations in hand surgery for patients in remote areas during the COVID-19 era. However, traditional physical examination is challenging in telemedicine and it is inconvenient to manually measure the hand range of motion (ROM) from images or videos. Here, we propose an automatic method using the hand pose estimation technique, aiming to measure the hand ROM from smartphone images. METHODS: Twenty-eight healthy volunteers participated in the study. An eight-hand gestures measurement protocol and the Google MediaPipe Hands were used to analyze images and calculate the ROM automatically. Manual goniometry was also performed according to the guideline of the American Medical Association. The correlation between the automatic and manual methods was analyzed by the intraclass correlation coefficient and Pearson correlation coefficient. The clinical acceptance was testified using Bland-Altman plots. RESULTS: A total of 32 parameters of each hand were measured by both methods, and 1792 measurement results were compared. The mean difference between automatic and manual methods is -2.21 ± 9.29° in the angle measurement and 0.48 ± 0.48 cm in the distance measurement. The intraclass correlation coefficient of 75% of parameters was higher than 0.75, the Pearson correlation coefficient of 84% of parameters was over 0.6, and 40.6% of parameters reached well-accepted clinical agreements. CONCLUSIONS: The proposed method provides a helpful protocol for automatic hand ROM measurement based on smartphone images and the MediaPipe Hands pose estimation technique. The automatic measurement is acceptable and comparable with existing methods, showing a possible application in the telemedicine examination of hand surgery.

Precision and accuracy of measuring finger motion with a depth camera: a cross-sectional study of healthy participants.

The purpose of this cross-sectional study was to determine the precision and accuracy of the measurement of finger motion with a depth camera. Fifty-five healthy adult hands were included. Measurements were done with a depth camera and compared with traditional manual goniometer measurements. Repeated measuring showed that the overall repeatability and reproducibility of extension measured with the depth camera were within 3° and 4° and that of flexion were within 13° and 14°. Compared with traditional manual goniometry, biases of extension of all finger joints and flexion of metacarpophalangeal joints were less than 5°, and the average bias of flexion of proximal and distal interphalangeal joints was 29°. We conclude that the measurement of finger extension and flexion of the metacarpophalangeal joints with a depth camera was reliable, but improvement is required in the precision and accuracy of interphalangeal joint flexion.

Validity and Reliability of a Depth Camera-Based Quantitative Measurement for Joint Motion of the Hand.

Purpose: Quantitative measurement of hand motion is essential in evaluating hand function. This study aimed to investigate the validity and reliability of a novel depth camera-based contactless automatic measurement system to assess hand range of motion and its potential benefits in clinical applications. Methods: Five hand gestures were designed to evaluate the hand range of motion using a depth camera-based measurement system. Seventy-one volunteers were enrolled in performing the designed hand gestures. Then, the hand range of motion was measured with the depth camera and manual procedures. System validity was evaluated based on 3 dimensions: repeatability, within-laboratory precision, and reproducibility. For system reliability, linear evaluation, the intraclass correlation coefficient, paired t -test and bias were employed to test the consistency and difference between the depth camera and manual procedures. Results: When measuring phalangeal length, repeatability, within-laboratory precision, and reproducibility were 2.63%, 12.87%, and 27.15%, respectively. When measuring angles of hand motion, the mean repeatability and within-laboratory precision were 1.2° and 3.3° for extension of 5 digits, 2.7° and 10.2° for flexion of 4 fingers, and 3.1° and 5.3° for abduction of 4 metacarpophalangeal joints, respectively. For system reliability, the results showed excellent consistency (intraclass correlation coefficient = 0.823; P < .05) and good linearity with the manual procedures (r = 0.909-0.982, approximately; P < .001). Besides, 78.3% of the measurements were clinically acceptable. Conclusions: Our depth camera-based evaluation system provides acceptable validity and reliability in measuring hand range of motion and offers potential benefits for clinical care and research in hand surgery. However, further studies are required before clinical application. Clinical relevance: This study suggests a depth camera-based contactless automatic measurement system holds promise for assessing hand range of motion in hand function evaluation, diagnosis, and rehabilitation for medical staff. However, it is currently not adequate for all clinical applications.

Value of the combination of a smartphone-compatible infrared camera and a hand-held doppler ultrasound in preoperative localization of perforators in flaps.

This study was conducted to evaluate the effectiveness of the FLIR ONE PRO, a thermal imaging camera for smartphones, combined with handheld Doppler (HHD) in the localization of perforator arteries and to assess the efficacy of the FLIR ONE PRO in distinguishing perforators of the descending branch of the lateral circumflex femoral artery (LCFA) from other perforators of the anterolateral thigh perforator (ALTP) flap. We enrolled 29 free perforator flaps from 22 patients in our study. Before surgery, dynamic infrared thermography was performed using a FLIR ONE PRO to visualize hotspots on the flaps. Subsequently, HHD was used to further determine the perforators under the hotspots, which were ultimately identified and confirmed through intraoperative findings. Additionally, infrared images of the ALTP flap were analyzed using FLIR Tools. The performances of the FLIR ONE PRO and FLIR ONE PRO + HHD groups were evaluated by comparing the intraoperative findings. Using FLIR ONE PRO + HHD, 119 hotspots and 106 perforators were identified during surgery. Using FLIR ONE PRO + HHD, sensitivity and positive predictive value were 97.87% and 88.46%, respectively, in the young (age≤45 years). In the elderly group (age>45 years), these percentages were 93.22% and 82.09%, respectively. In addition, we found that the FLIR ONE PRO could be useful for differentiating perforators in the descending branch of the LCFA from other perforators within 5 min. The results showed a sensitivity of 96.15%, a specificity of 98.9%, a positive predictive value of 96.15%, and a negative predictive value of 98.9%. Compared to using FLIR ONE PRO alone, the combined application of HHD and FLIR ONE PRO had a higher value in perforator localization by increasing the positive predictive value. The FLIR ONE PRO may have significance in the rapid prediction of perforators deriving from the descending branch of the LCFA.

A comparative study of human and porcine-derived decellularised nerve matrices.

Decellularised extracellular matrix (dECM) biomaterials originating from allogeneic and xenogeneic tissues have been broadly studied in the field of regenerative medicine and have already been used in clinical treatments. Allogeneic dECMs are considered more compatible, but they have the drawback of extremely limited human tissue sources. Their availability is also restricted by the health and age of the donors. To investigate the viability of xenogeneic tissues as a substitute for human tissues, we fabricated both porcine decellularised nerve matrix (pDNM) and human decellularised nerve matrix for a comprehensive comparison. Photomicrographs showed that both dECM scaffolds retained the ECM microstructures of native human nerve tissues. Proteomic analysis demonstrated that the protein compositions of both dECMs were also very similar to each other. Their functional ECM contents effectively promoted the proliferation, migration, and maturation of primary human Schwann cells in vitro. However, pDNM contained a few antigens that induced severe host immune responses in humanised mice. Interestingly, after removing the α-galactosidase antigen, the immune responses were highly alleviated and the pre-treated pDNM maintained a human decellularised nerve matrix-like pro-regenerative phenotype. Therefore, we believe that an α-galactosidase-free pDNM may serve as a viable substitute for human decellularised nerve matrix in future clinical applications.

A decellularized nerve matrix scaffold inhibits neuroma formation in the stumps of transected peripheral nerve after peripheral nerve injury.

Traumatic painful neuroma is an intractable clinical disease characterized by improper extracellular matrix (ECM) deposition around the injury site. Studies have shown that the microstructure of natural nerves provides a suitable microenvironment for the nerve end to avoid abnormal hyperplasia and neuroma formation. In this study, we used a decellularized nerve matrix scaffold (DNM-S) to prevent against the formation of painful neuroma after sciatic nerve transection in rats. Our results showed that the DNM-S effectively reduced abnormal deposition of ECM, guided the regeneration and orderly arrangement of axon, and decreased the density of regenerated axons. The epineurium-perilemma barrier prevented the invasion of vascular muscular scar tissue, greatly reduced the invasion of α-smooth muscle actin-positive myofibroblasts into nerve stumps, effectively inhibited scar formation, which guided nerve stumps to gradually transform into a benign tissue and reduced pain and autotomy behaviors in animals. These findings suggest that DNM-S-optimized neuroma microenvironment by ECM remodeling may be a promising strategy to prevent painful traumatic neuromas.

[Accuracy of key point matrix technology based contactless automatic measurement for joint motion of hand].

Objective: To validate the use of key point matrix technology based contactless automatic measurement for evaluation of joint motion of hand. Methods: Thirty-three volunteers were enrolled to evaluate the extension and flexion of hand joints between May 2021 and November 2021. There were 20 males and 13 females, the age ranged from 16 to 70 years with an average of 30.2 years. The extension angles of 14 joints of 5 fingers (including hyperextension) and the flexion angles of 12 joints of 4 fingers (excluding thumb) of volunteers were measured by key point matrix technology and manual goniometer, respectively. Then 5 participants and repeated measurement experiment were employed to test the system repeatability and accuracy; 28 participants and paired measurement experiment were employed to test the system accuracy. Results: The average repeatability of finger joint motion measured by the key point matrix technology was 1.801° (extension) and 7.823° (flexion), respectively. Compared with manual measurement, the average differences of each finger joint measured by the key point matrix technology were 3.225° in extension and 14.145° in flexion, respectively. The key point matrix technology based contactless automatic evaluation system offered excellent consistency with the manual goniometers ( ICC=0.875). While most of the consistency with manual goniometer of individual joints were at moderate levels (median of ICC, 0.440). The correlation coefficients between the measurement results of the two methods were mainly positive in the extension of the joint ( P<0.05) and negative in the flexion of the joints ( P<0.05). Conclusion: The key point matrix technology based contactless automatic evaluation provides sufficient measurement repeatability and accuracy in evaluation for the joint motion of hand.