Risk factors for cement leakage and nomogram for predicting the intradiscal cement leakage after the vertebra augmented surgery.

BACKGROUND: Vertebral augmentation is the first-line treatment for the osteoporosis vertebral compression fractures. Bone cement leakage is the most common complication of this surgery. This study aims to assess the risk factors for different types of cement leakage and provides a nomogram for predicting the cement intradiscal leakage. METHODS: We retrospectively reviewed 268 patients who underwent vertebral augmentation procedure between January 2015 and March 2019. The cement leakage risk factors were evaluated by univariate analysis. Different types of cement leakage risk factors were identified by the stepwise logistic analysis. We provided a nomogram for predicting the cement intradiscal leakage and used the concordance index to assess the prediction ability. RESULTS: A total of 295 levels of vertebrae were included, with a leakage rate of 32.5%. Univariate analysis showed delayed surgery and lower vertebral compression ratio were the independent risk factors of cement leakage. The stepwise logistic analysis revealed percutaneous vertebroplasty was a risk factor in vein cement leakage; delayed surgery, preoperative compression ratio, and upper endplate disruption were in intradiscal cement leakage; age, preoperative fracture severity, and intravertebral vacuum cleft were in perivertebral soft tissue cement leakage; no factor was in spinal canal cement leakage. The nomogram for intradiscal cement leakage had a precise prediction ability with an original concordance index of 0.75. CONCLUSIONS: Delayed surgery and more vertebral compression increase the risk of cement leakage. Different types of cement leakage have different risk factors. We provided a nomogram for precise predicting the intradiscal cement leakage.

A Modified Foot and Ankle Score for Assessing Patient Outcomes After First Metatarsophalangeal Arthrodesis.

First metatarsophalangeal (MTP) arthrodesis is commonly used to treat many end-stage first MTP diseases. The most widely used scale for measuring the clinical outcomes after this procedure, the American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal-Interphalangeal scale, has not been adequately validated and does not measure specific foot functions. Another outcome measure, the patient-reported Foot and Ankle Outcome Score (FAOS) has acceptable construct validity but poor content validity. The FAOS scale has 42 questions, many of which are unrelated to the hallux. We designed a short-form FAOS (sf-FAOS) consisting of 11 questions that are more relevant to first MTP arthrodesis. The sf-FAOS includes a pain subscale and a function subscale, and the score of each subscale ranges from 0 (worst outcome) to 100 (best outcome). Our study has shown that the sf-FAOS scale has acceptable validity, reliability, and responsiveness. In 21 feet (16 patients) with hallux valgus after >1 year of follow-up, the mean sf-FAOS pain score had improved by 44.9 points after surgery (from 51.2 to 96.0; p < .001), and the mean sf-FAOS function score had improved by 22.5 points (from 47.3 to 69.8; p <.001). The improvement in the function score for running and jumping was limited.

A special healing pattern in stable metaphyseal fractures.

BACKGROUND AND PURPOSE: Metaphyseal fractures heal in a rapid fashion that is different from the bone shaft healing process. Animal studies have focused on diaphyseal fractures. We investigated the metaphyseal fracture-healing process in rabbits. ANIMALS AND METHODS: 60 rabbits (divided into 12 groups) underwent proximal tibial osteotomy, anatomical reduction, and fixation with screws. After surgery, the proximal tibiae were harvested at different time points for histology. RESULTS: No obvious osteonecrosis or bone resorption were found 2 weeks after surgery. From day 5 to week 5, woven bone or new trabeculae formed. From week 2, remodeling into lamellar bone started and reached a peak at week 6. These 3 stages overlapped. Histomorphometry showed that the structure changed as a unimodal curve. INTERPRETATION: The healing process of metaphyseal fractures appears to differ from the commonly studied healing process in diaphyseal fractures. It is rapid, and can be divided into 4 histological stages: cellular activation and differentiation, formation of woven bone, transformation of woven bone into lamellar bone, and further remodeling.

[Multi-center retrospective analysis of clinical and related sociologic characteristics of postoperative distal radius fracture patients].

OBJECTIVE: To study clinical-related characteristics of sociology of postoperative distal radius fracture patients. METHODS: A multi-center retrospective research was conducted on the information of the case evaluation and follow-up, including the patients' gender, age, habits, history of chronic diseases, conditions of fracture, length of hospital stay and treatments. The epidemiology data were analyzed with SPSS15.0. RESULTS: Of the entire 143 patients, 52 were male (average age: 41), and 91 were female (average age: 61). The different gender and age groups had significant distinction in the characteristics of injury. The length of hospital stay was influenced by the energy of injury. CONCLUSION: To reduce the damage or incidence of distal radius fracture, we should avoid falling, strengthen protection awareness, treat internal medicine diseases or osteoporosis and so on. The knowledge of characteristics of sociology and injury of distal radius fracture is beneficial to the prevention and treatment.

[Nerve baby-sitter in reverse end-to-side neurorrhaphy preserves the structure of denervated muscle in rats].

OBJECTIVE: To explore the protected effect of sensory baby-sitter in reverse end-to-side fashion on denervated muscle. METHODS: The tibial nerve of twelve female adult Sprague Dawley rats was transected. Six animals served as controls. In the other rats, the end of the sural nerve was connected to the side of the distal tibial nerve stump. After twelve weeks, the wet weight, cross-sectional area, motor endplate perimeter from gastrocnemius muscle were examined. RESULTS: The difference in wet weight between the experimental group and the control group was statistically significant (39.2% ± 6.8% vs. 19.5% ± 4.3%, P<0.05). Histological observation of the unprotected muscles displayed wide areas of atrophied fibers and considerable connective tissue hyperplasia, whereas the structure of the experimental rats was preserved and there was only a slight increase in connective tissue. The average cross-sectional area and motor endplate perimeter of muscle fibers were significantly larger in the experimental group than in the control group [(1 148.85 ± 547.18) µm² vs. (575.05 ± 140.51) µm², (102.84 ± 53.29) µm vs. (59.60 ± 26.71) µm, respectively]. CONCLUSION: Sensory baby-sitter in reverse end-to-side neurorrhaphy preserves the structure of denervated muscle in rats.

[Surgical treatment of internal fixation failure after clavicular fracture operation].

OBJECTIVE: To investigate the surgical treatment results of implant failure after clavicular fracture open reduction and internal fixation (ORIF). METHODS: Fifteen cases from Jan. 2005 to Jan. 2013 were treated surgically according to fracture classification, time of implant failure and implant type. The fracture union, shoulder function and pain were evaluated postoperatively. RESULTS: All the patients had full follow-up for 5 to 101 months (mean: 43.8 months). All the fractures were united well. The constant scores to assess the shoulder function were 82 to 100 (mean: 93.3 in the fracture side) and were 85 to 100 (mean: 96.7 in the uninjured side); statistically significant difference of the constant scores between the two sides was found (P=0.02). Eight cases did not have shoulder pain in the fracture side, while the other 7 cases had mild pain, The visual analogue scale (VAS) scores to evaluate shoulder pain were 1 to 3 in the fracture side, which were statistically different from those in the uninjured side (P=0.03). CONCLUSION: Implant instability causes early implant failure after clavicular fracture ORIF and re-fixation with stable implant is effective. Fracture nonunion leads to late implant failure, and bridging fixation using locking plate associated with bony autograft with iliac crest is a successful method to treat atrophy clavicular nonunion. Surgical treatment can bring good results.

[Traffic injuries of pre-hospital treatment in the urban area of Beijing].

OBJECTIVE: To evaluate the current condition of urban road traffic injuries (RTIs) according to Beijing Emergency Medical Center (BEMC) from Jan. 1, 2004 to Dec. 31, 2010, analyze the social characteristics and explore the possible methods for prevention and improvement. METHODS: Using data from the Beijing Emergency Medical Center, we collected 19 550 victims who were involved in RTIs in Beijing from Jan. 1, 2004 to Dec. 31, 2010. The personal information, time of the injury event, road user type and striking vehicle type, as well as the site and severity of injury, were analyzed using Excel 2007 and SPSS 17.0 software with ANOVA of variance and Chi-squared tests. RESULTS: The annual rate of RTIs was 120.0 per 100 000 people in Beijing, and the mortality rate was about 4.97 per 100 000 people. Male victims were more than female victims (11 737 persons vs. 7 618 persons).The mean age was (72.92 ± 5.67) years. Overall, RTIs in all the age groups happened in October commonly, and were inclined to daytime, especially at noon. But different age groups had their special hour distribution features of RTIs. Traffic collisions occurred most frequently in pedestrians and cyclists (7 588,38.81%;3 790,19.39%). Majorities of victims presented with head injuries and lower-limb injuries(8 343,42.68%; 6 828,34.93%). These collisions included car striking accidents (11 490, 58.77%). And most of the older adults were classified as medium in severity (11 718, 59.94%). CONCLUSION: The prevention and treatment of RTIs, should focus on targeted prevention solutions and standardized pre-hospital rescue, according to specific population, time interval and vehicle usage.

[Effect of cement implantation and pressor agents in hip replacement on blood pressure].

OBJECTIVE: To discuss the change of blood pressure involved by pressor agents after the implantation of cement in hip replacement. METHODS: A total of 172 cases of femoral neck fracture underwent hip replacement in Department of Orthopedics and Trauma, Peking University People's Hospital between July 2008 and July 2013 were involved in this retrospective study. The blood pressure and usage of pressor agents were recorded before and after bone cement implantation. The data of blood pressure and usage of agents were collected according to anesthesia records. All the cases were divided into four groups by the application of pressor agents: Free of using agent group (Free-agent group), agents used before implantation of cement group (Pre-agent group), agents used after implantation of cement group (Post-agent group) and agent used before & after implantation of cement group (Pre and Post-agent group). Further statistic analysis was then performed. RESULTS: Free-agent group's mean systolic blood pressure decreased for (4.0 ± 10.3) mmHg. The decreasing was significant (t=3.660, P=0.000). Free-agent group's mean diastolic blood pressure decreased (1.3 ± 7.5) mmHg. The decreasing was not significant (t=2.286, P=0.149). Pre-agent group's mean systolic blood pressure decreased for (0.5 ± 20.2) mmHg. The decreasing was not significant (t=0.114, P=0.911). Pre-agent group's mean diastolic blood pressure increased (0.7 ± 10.2) mmHg. The increasing was not significant (t=-0.316, P=0.756). Post-agent group's mean systolic blood pressure decreased for (6.9 ± 15.0) mmHg. The decreasing was significant (t=3.195, P=0.002). Post-agent group's mean diastolic blood pressure decreased (3.6 ± 7.4) mmHg. The decreasing was significant (t=3.407,P=0.001). Pre & Post-agent group's mean systolic blood pressure decreased for (5.0 ± 12.2) mmHg. The decreasing was not significant (t=1.667, P=0.115). Pre & Post-agent group's mean diastolic blood pressure increased (1.3 ± 8.5) mmHg. The increasing was not significant (t=-0.656, P=0.521). CONCLUSION: Implantation of cement in hip replacement surgery causes blood pressure decreasing. The application of pressor agents before cement implantation can stabilize blood presure and shorten the period of hypotension.

[Central placement of screw fixation for scaphoid fracture: a biomechanical study].

OBJECTIVE: To evaluate the effect to the fixation stability of central screw placement during scaphoid fracture surgery. METHODS: We designed oblique osteotomies for 32 identical sawbone scaphoids and fixed each specimen with a cannulated screw. Sawbone scaphoids were divided into 4 groups, according to position of the osteotomy (distal waist portion or proximal waist portion) and the position of the screw (central or eccentric). We performed Computed Tomography scanning to one specimen, and then the central zone of the scaphoid was established from volume data by using the preoperative planning system software (VxWork 4.0). The position of the osteotomy plane, the entrance and exit points of the screw guide pin were designed on the software as well. We placed the specimens under the increasing load of a pneumatically driven plunger to compare the load to failure and the distance at failure between the central and eccentric screw groups. RESULTS: In general, we found the statistical differences of the load to failure and the displacement of fracture between the groups (F=31.485,P=0.001; F=33.328,P=0.018). The average load to failure and fracture displacement was more statistically different in the central group [(80.82 ± 15.63) N, (2.3 ± 0.5) mm] for proximal waist fracture than in the eccentric group [(58.32 ± 17.18) N, (3.1 ± 0.5) mm]. As to the distal waist fracture, the average load to failure and fracture displacement was better in the central group [(76.83 ± 14.54) N, (2.2 ± 0.7) mm] than in the eccentric group [(70.38 ± 13.32) N, (2.5 ± 0.6) mm] without significant difference. CONCLUSION: In this biomechanical model of an unstable oblique scaphoid fracture, we find that higher stability of fixation has been achieved with a screw placed centrally in the scaphoid, compared with a screw peripherally placed.

[Minimal invasive internal fixation with U-shaped break-off pedicle screws for treatent of thoracolumbar fractures].

OBJECTIVE: To investigate the clinical outcome of minimal invasive internal fixation with U-shaped break-off pedicle screws through paraspinal muscle sparing approach to treat thoracolumbar fractures, and to discuss its advantages. METHODS: From August 2010 to June 2012, we had 40 thoracolumber fractures patients (27 males and 13 females). Their ages ranged from 22 to 60 years. Of the 40 cases, 4 were T11 fractures, 13 T12 fractures ,17 L1 fractures,6 L2 fractures. According to Denis classification,all of them were burst fractures, with vertebral canal compromise less than 1/3. According to AO classification they were type A or type B1 injuries. All the cases had no nerve injury. The patients were randomly divided into two groups. With Group A (20 cases) we took the method of minimal invasive internal fixation with U-shaped break-off pedicle screws to fix one level above and below the injured vertebra through the parespinal muscle sparing approach. With Group B (20 cases), we took the traditional posterior midline approach and open procedure. Then we compared the two groups by operation time, blood loss, drainage, Visual Analogue Scales and X-ray exposure. RESULTS: Minimal invasive group had obvious advatages in operation time, bleeding control and early pain relief of post-operation. The X-ray exposure and long-term follow-up outcome were almost the same. CONCLUSION: Through paraspinal muscle sparing approach minimal invasive internal fixtation with U-shaped break-off pedicle screws to treat thoracolumber has more advantages than traditional procedure in blood control and quick recovery. The method needs no special instruments and don't increase X-ray exposure.

[Surgical treatment of deltoid ligament injury associated with ankle fractures].

OBJECTIVE: To observe the clinical outcome after the surgical treatment of the deltoid ligament injury associated with ankle fractures. METHODS: From January 2005 to December 2009, 16 deltoid ligament ruptures associated with ankle fractures were repaired. According to the AO/OTA system, 2 cases belonged to fracture A, 8 to B, and 6 to C. Radiographs, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores and visual analogue scale (VAS) were used for the outcome measurements. RESULTS: The 16 patients were followed up for 30 to 84 months,with the mean follow-up of 47 months. All wounds healed at the first stage. The mean time of bone union was 12.8 weeks (range: 10-14 weeks). The mean AOFAS ankle-hindfoot score in the last follow-up was 93 points (range: 85-100 points). The mean score of VAS was 0.94 points (range: 0-2 points). CONCLUSION: Surgical treatment of ankle fractures associated with deltoid ligament rupture can achieve satisfactory outcomes, but it is important to decide the operation indication.

[Generation and characterization of peripheral nerve animal model of pure motor/sensory nerve fibers].

OBJECTIVE: To generate peripheral nerve animal model of pure motor nerve fibers/pure sensory nerve fibers, and identify them. METHODS: The SPF SD rats were adopted in this study, and divided into 3 groups. In group A, we ablated L2-L4 ventral roots (VRs) to generate peripheral nerve animal model of pure sensory fibers. In group B, we ablated L2-L4 dorsal root ganglions (DRGs) to generate peripheral nerve animal model of pure motor fibers. Two time end-points were set as 2 weeks and 4 weeks. Neuron cells in lumbar spinal cords were detected by immunohistochemical staining with antibody of neuronal nuclei (NeuN). Motor neuron cells in lumbar spinal cords of pure motor fiber animal models and sensory neuron cells in lumbar spinal cords of pure sensory fiber animal models were counted respectively, and then compared to that of normal animals. Femoral nerves distal to the furcation were stained in osmium tetroxide, and then myelinated nerve fibers in the muscle branch and cutaneous branch of femoral nerve were counted respectively. RESULTS: The mean numbers of sensory neuron cells and motor neuron cells in normal lumbar spinal cords were 62.57 ± 1.02 and 29.73 ± 3.03 per 10 × 20 visual field respectively. For different end-points, the mean numbers of sensory neuron cells after ablating vental foots were 62.12 ± 1.77 (2 weeks), 62.15 ± 1.32 (4 weeks) per 10 × 20 visual field respectively; the mean numbers of motor neuron cells after ablating DRGs were 30.12 ± 0.44 (2 weeks), 30.00 ± 1.87 (4 weeks) per 10 × 20 visual field respectively. In group A, motor axons in muscle branch were degenerated as the sensory axons in muscle branch and cutaneous branch were not changed. The senory axons in femoral nerve for the two end-points were 1 558.17 ± 50.14 (2 weeks) and 1 544.00 ± 47.42 (4 weeks). In group B, sensory axons in muscle branch were degenerated as the motor axons were reserved. The motor axons in muscle branch for the two end-points were 387.67 ± 48.50 (2 weeks) and 393.50 ± 27.86 (4 weeks). There was no statistically significant difference in these mean numbers for the two end-points. The degenerating axons and myelin sheath had not been totally eliminated by the endpoint of 2 weeks. CONCLUSION: Peripheral nerve animal model of pure motor fibers can be generated by ablating L2-L4 DRGs; peripheral nerve animal model of pure sensory fibers can be generated by ablating L2-L4 ventral roots. The degenerating axons and myelin sheath have been totally eliminated by the end-point of 4 weeks. Ablating the ventral roots does not influence the survival of sensory neuron cells; and ablating the DRGs does not influence the survival of motor neuron cells.

[Treatment of comminuted clavicle shaft fractures with provisional intra-medullary K-wire fixation and bridging plate internal fixation].

OBJECTIVE: To discuss the operation effect of comminuted clavicle shaft fractures with provisional intramedullary K-wire fixation and bridging plate internal fixation. METHODS: From Mar. 2008 to Jul. 2012, 22 cases of comminuted clavicle shaft fractures was treated with open reduction, and provisional intramedullary K-wire fixation and bridging plate internal fixation. The fracture healing was investigated through X-rays. The 22 cases were followed up to evaluate the function of the affected shoulder with Constant score. RESULTS: Through the follow-up for average 15 months, all the fractures healed and the average healed time was 14.6 weeks. The average Constant score of the affected shoulder was 95.3. There were 13 excellent cases, 7 good cases, and 2 fair cases. The fineness rate was 90.9% (20/22). Soft tissue problem resulting from plate tilting occurred in 2 cases. At last, they accepted second operation to remove the implant. CONCLUSION: Applying provisional intramedullary K-wire fixation and bridging plate internal fixation in comminuted clavicle shaft fractures, makes procedure simple, improves healing rate and decreases the complications.

[Radix hedysari extract promotes peripheral nerve regeneration].

Treatment of peripheral nerve injury is a major challenge in clinical practice. With advances in molecular biology and development of microsurgical techniques and tissue engineering, peripheral nerve repair procedures have been greatly improved. In the last 10 decades, most treatments for peripheral nerve injury in animal models have achieved histological and functional recovery, the treatments in humans, however, produce insufficient recovery, especially for proximal nerve injury. Increasing attention has been paid to the Traditional Chinese Medicine (TCM) for promoting peripheral nerve regeneration, since these remedies often display effective clinical outcome, minor side effects and effectiveness for multiple targets. Although TCM has complex ingredients and the specific pharmacological mechanisms for their effectiveness are still unclear, an effective clinical outcome is welcomed by many clinicians. In the past 20 years, we have made a series of detailed studies including the toxicity tests, pharmacodynamic tests, pharmacological experiments etc, about a new traditional formula which mainly contains the Radix hedysari, Epimedium etc. RESULTS have shown that this formula is safe to be used in both animals and humans with no toxicity and adverse effect, and systemic administration of this formula could enhance the peripheral nerve regeneration.

[Pain assessment of biological conduit small gap tubulization in rat sciatic nerve multilation model].

OBJECTIVE: To explore the pain sensation recovery discipline of 2 mm small gap biological conduit tubulization and epineurial neurorrhaphy in rat sciatic nerve multilation model. METHODS: Based on the rat sciatic nerve multilation model, 2 mm small gap biological conduit tubulization and epineurial neurorrhaphy were applied and the 50% paw withdrawal threshold was observed after 2, 4, 5, 6, 8 and 12 weeks. The data were analyzed by two-way ANOVA and chi-square criterion. RESULTS: Obvious hyperalgesia was observed in week 2 in both experimental group and control group, and 50% paw withdrawal threshold was improved significantly even to 15 g. The 50% paw withdrawal threshold began to decline week 4 and the 50% paw withdrawal threshold of small gap tubulization group was obviously lower than that of control group, which may imply that the pain sensation recovery of small gap tubulization group was earlier than that of control group. The 50% paw withdrawal threshold of small gap tubulization group began to increase to the plateau period [week 5: (12.70 ± 5.64) g; week 6: (12.20 ± 3.26) g; week 8: (12.31 ± 4.19) g; week 12: (13.95 ± 2.58) g]. The 50% paw withdrawal threshold of control group declined gradually [week 5: (10.47 ± 7.02) g; week 6: (9.42 ± 6.86) g; week 8: (8.50 ± 7.15) g; week 12: (8.06 ± 5.93) g]. The difference was statistical significant between small gap tubulization group and control group in 12th week. CONCLUSION: Compared with the traditional epineurial neurorrhaphy for peripheral nerve multilation, 2 mm small gap biological conduit tubulization can improve the 50% paw withdrawal threshold during peripheral nerve regeneration process and reduce the pain incidence.

A new flavonoid from Epimedium brevicornu Maxim.

Epimedium brevicornu Maxim (E. brevicornu) is a plant of Epimedium L. in Berberidaceae, which is widely distributed and has high medicinal value and many important clinical applications. In this experiment, a novel flavonoid compound (1) was isolated and identified the chemical structure from E. brevicornu. The extract of E. brevicornu was performed on normal silica column chromatography, ODS silica column chromatography, Sephadex LH-20 column chromatography and RP-HPLC system to be isolated and purified and obtained 1. The HR-ESI-MS and NMR spectrometer were used to measure the accuracy molecular weights and determine the chemical structure of 1. In conclusion, we isolated and purified compound 1 (15.4 mg) and determined its chemical structure.

Respiratory Function Tolerance of Rats with Vaying Degrees of Thoracic Volume Reduction.

OBJECTIVE: To compare the effects of respiratory function on different degrees of reduced thoracic volume and evaluate the tolerance of rats with reduced thoracic volume, and to assess the feasibility of thoracic volume as a measure of the severity of rib fractures. METHODS: A total of 24 10-week-old female Sprague-Dawley (SD) rats were randomly divided into four groups (n = 6 in each group) according to the displacement degree of bilateral rib fractures (2, 4, 6, and 8 mm). The respiratory function of the rats（Tidal volume, Inspiration time, Expiration time, Breath rate, Minute volume, Peak inspiration flow) measured via whole-body barometric plethysmography before and after operation for 14 consecutive days. Respiratory function parameters of each group were analyzed. Chest CT scans were performed before and 14 days after operation, after that we reconstructed three-dimensional of the thoracic and lung and measured their volumes by computer software. We calculated the percentage of thoracic and lung volume reduction after operation. RESULTS: At the 14th day after the operation, the decline of thoracic volume rates of in the 2, 4, 6, and 8 mm groups were 5.20%, 9.01%, 16.67%, and 20.74%, respectively. The 8 mm group showed a significant reduction in lung volume. The postoperative tidal volumes were lower in each of the groups than the baseline values before the operation. The tidal volume of the 2 mm group gradually recovered after the operation and returned to a normal level (1.54 ± 0.07 mL) at 14th day after the operation. The tidal volume of the 4, 6, and 8 mm groups recovered gradually after the operation, but did not return to baseline level at the 14th day. In particular, the tidal volume of the 8 mm group was significantly lower than that of the other groups during the 14 days (1.23 ± 0.12 mL, p < 0.05). There were no significant changes in the inspiratory and expiratory times, peak inspiratory and expiratory flows, respiratory rate, and minute ventilation during the 14 days after the operation in each group. CONCLUSIONS: Displaced rib fractures lead to thoracic collapse and reduced thoracic volume, which can affect tidal volume in rats. The greater the decrease of thoracic volume, the more obvious the decrease of early tidal volume. The thoracic volume can be used as an objective parameter to evaluate the severity of multiple rib fractures. Early operation to restore thoracic volume may improve early respiratory function. Decreased thoracic volume affected respiratory function and can be compensated and recovered in the long term.

Mimosa-Inspired Stimuli-Responsive Curling Bioadhesive Tape Promotes Peripheral Nerve Regeneration.

Trauma often results in peripheral nerve injuries (PNIs). These injuries are particularly challenging therapeutically because of variable nerve diameters, slow axonal regeneration, infection of severed ends, fragility of the nerve tissue, and the intricacy of surgical intervention. Surgical suturing is likely to cause additional damage to peripheral nerves. Therefore, an ideal nerve scaffold should possess good biocompatibility, diameter adaptability, and a stable biological interface for seamless biointegration with tissues. Inspired by the curl of Mimosa pudica, this study aimed to design and develop a diameter-adaptable, suture-free, stimulated curling bioadhesive tape (SCT) hydrogel for repairing PNI. The hydrogel is fabricated from chitosan and acrylic acid-N-hydroxysuccinimide lipid via gradient crosslinking using glutaraldehyde. It closely matches the nerves of different individuals and regions, thereby providing a bionic scaffold for axonal regeneration. In addition, this hydrogel rapidly absorbs tissue fluid from the nerve surface achieving durable wet-interface adhesion. Furthermore, the chitosan-based SCT hydrogel loaded with insulin-like growth factor-I effectively promotes peripheral nerve regeneration with excellent bioactivity. This procedure for peripheral nerve injury repair using the SCT hydrogel is simple and reduces the difficulty and duration of surgery, thereby advancing adaptive biointerfaces and reliable materials for nerve repair.

Epidemiology and the economic burden of traumatic fractures in China: A population-based study.

Objectives: National data on the admission rate, distribution, in-hospital mortality, and economic burden of traumatic fractures in China is unclear. We aimed to conduct a cross-sectional population-based study to determine such above data at the national level in China. Methods: A national administrative database was used to review all traumatic fracture hospitalizations in China during 2020, from which a total of 2,025,169 inpatients with traumatic fractures was retrieved. Admission rates and in-hospital mortality rates stratified by age, sex, and region were calculated. The causes of traumatic fracture and economic burden were described. Results: The admission rate of traumatic fractures of all China population in 2020 was 1.437‰. The admission rate increased with age and varied with genders and causes of injuries. Falls are the leading cause of traumatic fracture hospitalization, followed by road traffic injuries. The most common diagnoses were femoral neck fractures, with a number of 138,377. The in-hospital mortality was 1.209‰. Road traffic injuries led to the highest in-hospital mortality. The median length of stay was 10 days, with the median hospitalization cost of ¥20,900 (about $3,056). Conclusion: Traumatic fractures are concerning conditions with a high admission rate and in-hospital mortality in China, which are mainly caused by falls and road traffic injuries. The government should implement more public health policies to enhance the health of the elderly and improve transportation safety to prevent traumatic fractures.

Multifunctional wet-adhesive chitosan/acrylic conduit for sutureless repair of peripheral nerve injuries.

The incidence of peripheral nerve injury (PNI) is high worldwide, and a poor prognosis is common. Surgical closure and repair of the affected area are crucial to ensure the effective treatment of peripheral nerve injuries. Despite being the standard treatment approach, reliance on sutures to seal the severed nerve ends introduces several limitations and restrictions. This technique is intricate and time-consuming, and the application of threading and punctate sutures may lead to tissue damage and heightened tension concentrations, thus increasing the risk of fixation failure and local inflammation. This study aimed to develop easily implantable chitosan-based peripheral nerve repair conduits that combine acrylic acid and cleavable N-hydroxysuccinimide to reduce nerve damage during repair. In ex vivo tissue adhesion tests, the conduit achieved maximal interfacial toughness of 705 J m-2 ± 30 J m-2, allowing continuous bridging of the severed nerve ends. Adhesive repair significantly reduces local inflammation caused by conventional sutures, and the positive charge of chitosan disrupts the bacterial cell wall and reduces implant-related infections. This promises to open new avenues for sutureless nerve repair and reliable medical implants.