Clinical trials have demonstrated that kilohertz-frequency transcutaneous spinal cord stimulation (TSCS) can be used to facilitate the recovery of sensory-motor function for patients with spinal cord injury, whereas the neural mechanism of TSCS is still undetermined so that the choice of stimulation parameters is largely dependent on the clinical experience. In this paper, a finite element model of transcutaneous spinal cord stimulation was used to calculate the electric field distribution of human spinal cord segments T ₁₂ to L ₂, whereas the activation thresholds of spinal fibers were determined by using a double-cable neuron model. Then the variation of activation thresholds was obtained by varying the carrier waveform, the interphase delay, the modulating frequency, and the modulating pulse width. Compared with the sinusoidal carrier, the usage of square carrier could significantly reduce the activation threshold of dorsal root (DR) fibers. Moreover, the variation of activation thresholds was no more than 1 V due to the varied modulating frequency and decreases with the increased modulating pulse width. For a square carrier at 10 kHz modulated by rectangular pulse with the frequency of 50 Hz and the pulse width of 1 ms, the lowest activation thresholds of DR fibers and dorsal column fibers were 27.6 V and 55.8 V, respectively. An interphase delay of 5 μs was able to reduce the activation thresholds of the DR fibers to 20.1 V. The simulation results can lay a theoretical foundation on the selection of TSCS parameters in clinical trials.
Humans ; Spinal Cord Stimulation/methods* ; Nerve Fibers/physiology* ; Finite Element Analysis ; Spinal Cord/physiology* ; Computer Simulation ; Spinal Cord Injuries/physiopathology* ; Lumbosacral Region ; Lumbar Vertebrae ; Transcutaneous Electric Nerve Stimulation/methods* ; Models, Neurological

OBJECTIVE: To discuss the elbow skin fold extension line in Kirschner wire internal fixation of extended supracondylar humeral fractures in children. METHODS: The clinical data of 58 children with extended supracondylar fractures of the humerus who met the selection criteria between August 2021 and July 2024 were retrospectively analyzed. In 28 cases, needle placement of medial epicondyle of humerus was performed with the assistance of the elbow skin fold extension line (study group), and 30 cases were assisted by routine touch of the medial epicondyle of the humerus (control group). There was no significant difference in baseline data such as gender, age, side, cause of injury, Gartland type, Kirschner wire configuration, and time from injury to operation between the two groups ( P>0.05). The closed reduction rate, total operation time, time of medial humeral condyle pin placement, fluoroscopy times during medial pin placement, rate of one-time determination of medial entry point, ulnar nerve injury incidence, and fracture healing time were recorded and compared between the two groups. At the same time, the closed reduction rate of patients with the time from injury to operation ≤24 hours and >24 hours was compared. The elbow function was evaluated by Mayo elbow function score. RESULTS: The closed reduction rate of the study group was significantly higher than that of the control group ( P<0.05). Among all patients, the closed reduction rate of patients with the time from injury to operation ≤24 hours [73.3% (22/30)] was significantly higher than that of patients >24 hours [42.9% (12/28)] ( χ ²=5.545, P=0.019). The total operation time, medial needle placement time, and fluoroscopy times in the study group were significantly less than those in the control group, and the one-time determination rate of medial needle entry point in the study group was significantly higher than that in the control group ( P<0.05). There were 4 cases of ulnar nerve injury in the control group, and no ulnar nerve injury in the study group, but there was no significant difference in the incidence of ulnar nerve injury between the two groups ( P>0.05). All patients were followed up 6-12 months (mean, 8 months). There was no bone nonunion in both groups, and the fracture healing time of the study group was significantly shorter than that of the control group ( P<0.05). Volkmann ischemic contracture, heterotopic ossification, myositis ossificans, and premature epiphyseal closure were not observed after operation. No complications such as loosening or fracture of Kirschner wire occurred. At last follow-up, the Mayo elbow joint function score was used to evaluate function, and there was no significant difference between the two groups ( P>0.05). CONCLUSION In the treatment of extended supracondylar fractures of the humerus in children, the elbow skin fold extension line can help to quickly locate the medial epicondyle of the humerus, quickly insert Kirschner wire, and reduce the operation time and trauma.
Humans ; Humeral Fractures/surgery* ; Bone Wires ; Male ; Female ; Fracture Fixation, Internal/instrumentation* ; Retrospective Studies ; Child ; Elbow Joint/physiopathology* ; Child, Preschool ; Treatment Outcome ; Fracture Healing ; Ulnar Nerve/injuries* ; Adolescent ; Range of Motion, Articular

OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

OBJECTIVE: To explore the effectiveness of arthroscopic release of elbow joint assisted by medial small incision ulnar nerve release in the treatment of non-traumatic elbow stiffness. METHODS: The clinical data of 15 patients with non-traumatic elbow stiffness treated with arthroscopic release of elbow joint assisted by medial small incision ulnar nerve release between April 2019 and September 2023 were retrospectively analyzed. There were 6 males and 9 females with an average age of 46 years ranging from 34 to 56 years. The causes included rheumatoid arthritis in 3 cases, gouty arthritis in 2 cases, loose bodies in 3 cases, and elbow osteoarthritis in 7 cases. There were 4 cases with ulnar neuritis and 3 cases with synovial osteochondromatosis. The duration of elbow stiffness ranged from 6 to 18 months, with an average of 10 months. The operation time and intraoperative blood loss were recorded. The effectiveness was evaluated by visual analogue scale (VAS) score, range of elbow motion (maximum flexion, maximum extension, and total flexion and extension), Mayo score, and Hospital for Special Surgery (HSS) elbow score. RESULTS: The operation time was 60-90 minutes, with an average of 65 minutes, and the intraoperative blood loss was 40-100 mL, with an average of 62 mL. All patients were followed up 13-18 months, with an average of 14 months. There was no complication such as vascular and nerve injury, poor wound healing, collateral ligament injury, elbow joint space narrowing, osteophyte proliferation, or loose body formation around the joint. At last follow-up, the elbow range of motion (maximum flexion, maximum extension, and total flexion and extension), VAS score, and Mayo score significantly improved when compared with those before operation ( P<0.05). The HSS elbow score was 85-95, with an average of 92; 12 cases were excellent, 3 cases were good, and the excellent and good rate was 100%. CONCLUSION Arthroscopic release of elbow joint assisted by medial small incision ulnar nerve release is an effective way to treat non-traumatic elbow stiffness, which has the advantages of small trauma, short operation time, and good effectiveness. It can carry out early elbow rehabilitation training and significantly improve elbow function.
Humans ; Male ; Female ; Arthroscopy/methods* ; Adult ; Middle Aged ; Elbow Joint/physiopathology* ; Retrospective Studies ; Range of Motion, Articular ; Treatment Outcome ; Ulnar Nerve/surgery* ; Operative Time

OBJECTIVE: To investigate the effects of removing microglia from spinal cord on nerve repair and functional recovery after spinal cord injury (SCI) in mice. METHODS: Thirty-nine 6-week-old female C57BL/6 mice were randomly divided into control group ( n=12), SCI group ( n=12), and PLX3397+SCI group ( n=15). The PLX3397+SCI group received continuous feeding of PLX3397, a colony-stimulating factor 1 receptor inhibitor, while the other two groups were fed a standard diet. After 14 days, both the SCI group and the PLX3397+SCI group were tested for ionized calcium binding adapter molecule 1 (Iba1) to confirm that the PLX3397+SCI group had completely depleted the spinal cord microglia. The SCI model was then prepared by clamping the spinal cord in both the SCI group and the PLX3397+SCI group, while the control group underwent laminectomy. Preoperatively and at 1, 3, 7, 14, 21, and 28 days postoperatively, the Basso Mouse Scale (BMS) was used to assess the hind limb function of mice in each group. At 28 days, a footprint test was conducted to observe the gait of the mice. After SCI, spinal cord tissue from the injury site was taken, and Iba1 immunofluorescence staining was performed at 7 days to observe the aggregation and proliferation of microglia in the spinal cord. HE staining was used to observe the formation of glial scars at the injury site at 28 days; glial fibrillary acidic protein (GFAP) immunofluorescence staining was applied to astrocytes to assess the extent of the injured area; neuronal nuclei antigen (NeuN) immunofluorescence staining was used to evaluate neuronal survival. And 5-hydroxytryptamine (5-HT) immunofluorescence staining was performed to assess axonal survival at 60 days. RESULTS: All mice survived until the end of the experiment. Immunofluorescence staining revealed that the microglia in the spinal cord of the PLX3397+SCI group decreased by more than 95% compared to the control group after 14 days of continuous feeding with PLX3397 ( P<0.05). Compared to the control group, the BMS scores in the PLX3397+SCI group and the SCI group significantly decreased at different time points after SCI ( P<0.05). Moreover, the PLX3397+SCI group showed a further decrease in BMS scores compared to the SCI group, and exhibited a dragging gait. The differences between the two groups were significant at 14, 21, and 28 days ( P<0.05). HE staining at 28 days revealed that the SCI group had formed a well-defined and dense gliotic scar, while the PLX3397+SCI group also developed a gliotic scar, but with a more blurred and loose boundary. Immunofluorescence staining revealed that the number of microglia near the injury center at 7 days increased in the SCI group than in the control group, but the difference between groups was not significant ( P>0.05). In contrast, the PLX3397+SCI group showed a significant reduction in microglia compared to both the control and SCI groups ( P<0.05). At 28 days after SCI, the area of spinal cord injury in the PLX3397+SCI group was significantly larger than that in SCI group ( P<0.05); the surviving neurons significantly reduced compared with the control group and SCI group ( P<0.05). The axonal necrosis and retraction at 60 days after SCI were more obvious. CONCLUSION The removal of microglia in the spinal cord aggravate the tissue damage after SCI and affecte the recovery of motor function in mice, suggesting that microglia played a neuroprotective role in SCI.
Animals ; Spinal Cord Injuries/surgery* ; Microglia/pathology* ; Female ; Mice ; Mice, Inbred C57BL ; Nerve Regeneration/drug effects* ; Spinal Cord/pathology* ; Pyrroles/administration & dosage* ; Aminopyridines/administration & dosage* ; Recovery of Function ; Disease Models, Animal ; Calcium-Binding Proteins/metabolism* ; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors* ; Microfilament Proteins/metabolism* ; Glial Fibrillary Acidic Protein/metabolism*

OBJECTIVE: To review the research progress on silk fibroin (SF)-nerve guidance conduits (NGCs) for peripheral nerve injury (PNI) repair. METHODS: To review the recent literature on PNI and SF-NGCs, expound the concepts and treatment strategies of PNI, and summarize the construction of SF-NGCs and its application in PNI repair. RESULTS: Autologous nerve transplantation remains the "gold standard" for treating severe PNI. However, it's clinical applications are constrained by the limitations of limited donors and donor area damage. Natural SF exhibits good biocompatibility, low immunogenicity, and excellent physicochemical properties, making it an ideal candidate for the construction of NGCs. SF-NGCs constructed using different technologies have been found to have better biocompatibility and bioactivity. Their configurations can facilitate nerve regeneration by enhancing regenerative guidance and axonal extension. Besides, the adhesion, proliferation and differentiation of neurons and Schwann cells related to PNI repair can be effectively promote by NGCs. This accelerates the speed of nerve regeneration and improves the efficiency of repair. In addition, SF-NGCs can be used as regenerative scaffolds to provide biological templates for nerve repair. CONCLUSION The biodegradable natural SF has been extensively studied and demonstrated promising application prospects in the field of NGCs. It might be an effective and viable alternative to the "gold standard" for PNI treatment.
Fibroins/chemistry* ; Peripheral Nerve Injuries/therapy* ; Nerve Regeneration ; Tissue Scaffolds/chemistry* ; Humans ; Guided Tissue Regeneration/methods* ; Biocompatible Materials ; Animals ; Tissue Engineering/methods* ; Schwann Cells/cytology* ; Peripheral Nerves ; Neurons/cytology*

OBJECTIVE: To explore the method and effectiveness of index finger proximal dorsal island flap supplied by the nutrient vessels of superficial branch of radial nerve for treatment of thumb skin and soft tissue defect. METHODS: Between August 2019 and December 2024, 12 patients with thumb skin and soft tissue defects caused by trauma accompanied by variation of the first dorsal metacarpal artery were treated. There were 8 males and 4 females, aged 19-55 years, with an average age of 32 years. The wound area ranged from 2.2 cm×2.0 cm to 5.5 cm×3.5 cm. The time from injury to operation ranged from 1.5 to 6.0 hours, with an average of 4.5 hours. After thorough debridement, the wound was repaired with a index finger proximal dorsal island flap supplied by the nutrient vessels of the superficial branch of the radial nerve. The flap area ranged from 2.4 cm×2.2 cm to 6.0 cm×4.0 cm. The donor site was repaired with free skin grafting. Regular follow-up was conducted postoperatively to observe the appearance, texture, sensory recovery of the flap, and the condition of the donor site. RESULTS: The operation time ranged from 30 to 72 minutes, with an average of 47 minutes; intraoperative blood loss ranged from 30 to 70 mL, with an average of 46 mL. After operation, partial necrosis occurred at the skin edge of the radial incision on the dorsum of the hand in 1 case, which healed after dressing changes; all other flaps survived uneventfully, with primary wound healing. The skin grafts at the donor sites all survived. All 12 patients were followed up 5-36 months, with an average of 14 months. The appearance and texture of the flaps were good. At last follow-up, the two-point discrimination of the flaps ranged from 4 to 9 mm, with an average of 5.2 mm. According to the functional evaluation criteria for upper limb issued by the Hand Surgery Society of Chinese Medical Association, the results were excellent in 11 cases and good in 1 case. No scar contracture, pain, or joint movement limitation was observed at the donor sites. CONCLUSION For patients with skin and soft tissue defects of the thumb accompanied by variation of the first dorsal metacarpal artery, the index finger proximal dorsal island flap supplied by the nutrient vessels of the superficial branch of the radial nerve can be selected. This method has advantages such as shorter operation time, less intraoperative bleeding, and good postoperative appearance and sensation of the flap.
Humans ; Male ; Adult ; Female ; Thumb/surgery* ; Soft Tissue Injuries/surgery* ; Radial Nerve/surgery* ; Middle Aged ; Surgical Flaps/innervation* ; Plastic Surgery Procedures/methods* ; Skin Transplantation/methods* ; Young Adult ; Treatment Outcome ; Fingers/surgery* ; Skin/injuries*

OBJECTIVE: To evaluate the analgesic efficacy of ultrasound-guided high fascia iliaca compartment block (HFICB) in managing tourniquet-related pain following total knee arthroplasty (TKA). METHODS: A prospective randomized controlled trial was conducted involving 84 patients with severe knee osteoarthritis or rheumatoid arthritis who underwent unilateral TKA between March 2024 and December 2024. Patients were randomly assigned to two groups ( n=42) using a random number table. In the trial group, ultrasound-guided HFICB was performed preoperatively, with 0.2% ropivacaine injected into the fascia iliaca compartment. No intervention was administered in the control group. Baseline characteristics, including gender, age, surgical side, body mass index, and preoperative visual analogue scale (VAS) scores at rest and during movement, showed no significant difference between the two groups ( P>0.05). In both groups, a tourniquet was applied after osteotomy and before pulsed lavage, and removed after the closure of the first layer of the joint capsule. Postoperative assessments were conducted at 6, 12, 24, and 48 hours, including VAS scores at the tourniquet site (at rest and during movement), Bromage motor block scores, Ramsay sedation scores, and Bruggrmann comfort scale (BCS) scores to evaluate patient comfort. Additionally, the average tramadol consumption and incidence of nausea and vomiting within 48 hours postoperatively were recorded and compared. RESULTS: In the trial group and control group, VAS scores during movement at the tourniquet site significantly improved at all postoperative time points compared to preoperative levels ( P<0.05). VAS scores at rest increased transiently at 6 hours after operation in both groups, and then gradually decreased to the preoperative level. Except that there was no significant difference at 48 hours after operation in the trial group ( P>0.05), there were significant differences at other time points of two groups compared to preoperative score ( P<0.05). Except for VAS score at rest at 6 hours, VAS score during movement at 48 hours, and BCS comfort score at 48 hours ( P>0.05), the trial group showed significantly better outcomes than the control group in terms of VAS score at rest, VAS score during movement, Ramsay sedation scores, and BCS comfort scores at all other time points ( P<0.05). No significant difference was found in Bromage motor block scores between the groups ( P>0.05). Tramadol was used in 3 patients in the trial group and 7 patients in the control group within 48 hours after operation, the dosage was (133.30±14.19) mg and (172.40±22.29) mg, showing significant difference ( P<0.05). Nausea and vomiting occurred in 4 patients (9.5%) in the trial group and 3 patients (7.1%) in the control group, with no significant difference in incidence between groups ( P>0.05). CONCLUSION Ultrasound-guided HFICB provides effective analgesia for tourniquet-related pain following TKA, facilitates early postoperative functional recovery of the knee joint, and may serve as a valuable clinical option for postoperative pain management in TKA patients.
Humans ; Arthroplasty, Replacement, Knee/adverse effects* ; Nerve Block/methods* ; Male ; Female ; Pain, Postoperative/etiology* ; Tourniquets/adverse effects* ; Prospective Studies ; Middle Aged ; Ropivacaine/administration & dosage* ; Aged ; Ultrasonography, Interventional ; Anesthetics, Local/administration & dosage* ; Pain Measurement ; Fascia ; Osteoarthritis, Knee/surgery* ; Treatment Outcome ; Arthritis, Rheumatoid/surgery*

OBJECTIVE: To review recent research progress in the use of auxiliary components of nerve conduits for the treatment of peripheral nerve injuries. METHODS: An extensive review of recent domestic and international literature was conducted to evaluate the role of auxiliary components in nerve conduits for peripheral nerve repair, with a focus on their effects and underlying mechanisms. RESULTS: By incorporating auxiliary components such as bioactive molecules, therapeutic cells, and their derivatives, nerve conduits can create a more biomimetic regenerative microenvironment. This is achieved by providing neurotrophic support, modulating the immune microenvironment, improving blood and oxygen supply, and offering directional guidance for nerve regeneration. Consequently, the nerve conduit is transformed from a simple physical scaffold into an active, bio-functional repair system, which enhances the effectiveness for PNI. CONCLUSION While nerve conduits augmented with auxiliary components demonstrate improved effectiveness, further advancements are required in drug delivery systems and the integration of cellular components. Moreover, most current studies are based on animal or in vitro experiments. Randomized controlled clinical trials are necessary to validate their clinical effectiveness.
Peripheral Nerve Injuries/surgery* ; Nerve Regeneration ; Humans ; Tissue Scaffolds ; Animals ; Guided Tissue Regeneration/methods* ; Tissue Engineering/methods* ; Biocompatible Materials ; Peripheral Nerves ; Drug Delivery Systems

OBJECTIVE: To investigate the effectiveness of endoscopic-assisted median nerve decompression with one-stage extensor indicis proprius (EIP) tendon transfer for reconstruction of thumb abduction in patients with severe carpal tunnel syndrome (CTS). METHODS: The clinical data of 12 patients with severe CTS who met the selection criteria between December 2019 and December 2024 were retrospectively analyzed. There were 2 males and 10 females with an average age of 55.4 years ranging from 35 to 67 years. The symptom duration of CTS was 12-120 months (mean, 48.7 months) and the thenar muscle atrophy duration was 6-48 months (mean, 13.4 months). The median nerve was released with the help of endoscope, and the EIP tendon was transferred to reconstruct the abduction function of the thumb. The operation time and complications were recorded. Two-point discrimination, palmar abduction angle of the thumb, radial abduction angle of the thumb, and pinch force of the thumb were measured and compared before operation and at last follow-up, and the effectiveness was evaluated by Kapandji score and Disabilities of the Arm, Shoulder and Hand (DASH) score. The satisfaction of the operation was evaluated at last follow-up. RESULTS: All surgeries were successfully completed with a mean operation time of 54 minutes (range, 45-68 minutes). All patients were followed up 6-50 months, with an average of 15.3 months. There was no complications such as wound infection, scar pain of wrist, or tendon rupture of transposition, and there were 3 cases of mild limitation of finger extension in the donor site of index finger. At last follow-up, two-point discrimination, palmar abduction angle of the thumb, radial abduction angle of the thumb, Kapandji score, and DASH score were significantly better than those before operation ( P<0.05), but there was no significant difference in thumb pinch force between pre- and post-operation ( P>0.05). The evaluation of surgical satisfaction showed that 7 cases were very satisfied and 5 cases were satisfied. CONCLUSION The combination of endoscopic-assisted median nerve decompression and one-stage EIP tendon transfer effectively improves hand function and quality of life in patients with severe CTS by restoring thumb abduction and alleviating neurological symptoms.
Humans ; Tendon Transfer/methods* ; Male ; Middle Aged ; Carpal Tunnel Syndrome/physiopathology* ; Female ; Decompression, Surgical/methods* ; Aged ; Adult ; Thumb/physiopathology* ; Endoscopy/methods* ; Retrospective Studies ; Median Nerve/surgery* ; Treatment Outcome ; Plastic Surgery Procedures/methods*