Strategies for Treating Traumatic Neuromas with Tissue-Engineered Materials

Neuroma, a pathological response to peripheral nerve injury, refers to the abnormal growth of nerve tissue characterized by disorganized axonal proliferation. Commonly occurring after nerve injuries, surgeries, or amputations, this condition leads to the formation of painful nodular structures. Traditional treatment options include surgical excision and pharmacological management, aiming to alleviate symptoms. However, these approaches often offer temporary relief without addressing the underlying regenerative challenges, necessitating the exploration of advanced strategies such as tissue-engineered materials for more comprehensive and effective solutions. In this study, we discussed the etiology, molecular mechanisms, and histological morphology of traumatic neuromas after peripheral nerve injury. Subsequently, we summarized and analyzed current nonsurgical and surgical treatment options, along with their advantages and disadvantages. Additionally, we emphasized recent advancements in treating traumatic neuromas with tissue-engineered material strategies. By integrating biomaterials, growth factors, cell-based approaches, and electrical stimulation, tissue engineering offers a comprehensive solution surpassing mere symptomatic relief, striving for the structural and functional restoration of damaged nerves. In conclusion, the utilization of tissue-engineered materials has the potential to significantly reduce the risk of neuroma recurrence after surgical treatment.

Growth factors: Bioactive macromolecular drugs for peripheral nerve injury treatment - Molecular mechanisms and delivery platforms

Bioactive macromolecular drugs known as Growth Factors (GFs), approved by the Food and Drug Administration (FDA), have found successful application in clinical practice. They hold significant promise for addressing peripheral nerve injuries (PNIs). Peripheral nerve guidance conduits (NGCs) loaded with GFs, in the context of tissue engineering, can ensure sustained and efficient release of these bioactive compounds. This, in turn, maintains a stable, long-term, and effective GF concentration essential for treating damaged peripheral nerves. Peripheral nerve regeneration is a complex process that entails the secretion of various GFs. Following PNI, GFs play a pivotal role in promoting nerve cell growth and survival, axon and myelin sheath regeneration, cell differentiation, and angiogenesis. They also regulate the regenerative microenvironment, stimulate plasticity changes post-nerve injury, and, consequently, expedite nerve structure and function repair. Both exogenous and endogenous GFs, including NGF, BDNF, NT-3, GDNF, IGF-1, bFGF, and VEGF, have been successfully loaded onto NGCs using techniques like physical adsorption, blend doping, chemical covalent binding, and engineered transfection. These approaches have effectively promoted the repair of peripheral nerves. Numerous studies have demonstrated similar tissue functional therapeutic outcomes compared to autologous nerve transplantation. This evidence underscores the substantial clinical application potential of GFs in the domain of peripheral nerve repair. In this article, we provide an overview of GFs in the context of peripheral nerve regeneration and drug delivery systems utilizing NGCs. Looking ahead, commercial materials for peripheral nerve repair hold the potential to facilitate the effective regeneration of damaged peripheral nerves and maintain the functionality of distant target organs through the sustained release of GFs.

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.

The Porous Structure of Peripheral Nerve Guidance Conduits: Features, Fabrication, and Implications for Peripheral Nerve Regeneration

Porous structure is an important three-dimensional morphological feature of the peripheral nerve guidance conduit (NGC), which permits the infiltration of cells, nutrients, and molecular signals and the discharge of metabolic waste. Porous structures with precisely customized pore sizes, porosities, and connectivities are being used to construct fully permeable, semi-permeable, and asymmetric peripheral NGCs for the replacement of traditional nerve autografts in the treatment of long-segment peripheral nerve injury. In this review, the features of porous structures and the classification of NGCs based on these characteristics are discussed. Common methods for constructing 3D porous NGCs in current research are described, as well as the pore characteristics and the parameters used to tune the pores. The effects of the porous structure on the physical properties of NGCs, including biodegradation, mechanical performance, and permeability, were analyzed. Pore structure affects the biological behavior of Schwann cells, macrophages, fibroblasts, and vascular endothelial cells during peripheral nerve regeneration. The construction of ideal porous structures is a significant advancement in the regeneration of peripheral nerve tissue engineering materials. The purpose of this review is to generalize, summarize, and analyze methods for the preparation of porous NGCs and their biological functions in promoting peripheral nerve regeneration to guide the development of medical nerve repair materials.

Micron track chitosan conduit fabricated by 3D-printed model topography provides bionic microenvironment for peripheral nerve regeneration

The micron track conduit (MTC) and nerve factor provide a physical and biological model for simulating peripheral nerve growth and have potential applications for nerve injury. However, it has rarely been reported that they synergize on peripheral nerves. In this study, we used bioderived chitosan as a substrate to design and construct a neural repair conduit with micron track topography using threedimensional (3D) printing topography. We loaded the MTC with neurotrophin-3 (NT-3) to promote the regeneration of sensory and sympathetic neurons in the peripheral nervous system. We found that the MTC@NT3 composite nerve conduit mimicked the microenvironment of peripheral nerves and promoted axonal regeneration while inducing the targeted growth of Schwann cells, which would promote functional recovery in rats with peripheral nerve injury. Artificial nerve implants with functional properties can be developed using the strategy presented in this study.

Tissue-Engineered Nanomaterials Play Diverse Roles in Bone Injury Repair

Nanomaterials with bone-mimicking characteristics and easily internalized by the cell could create suitable microenvironments in which to regulate the therapeutic effects of bone regeneration. This review provides an overview of the current state-of-the-art research in developing and using nanomaterials for better bone injury repair. First, an overview of the hierarchical architecture from the macroscale to the nanoscale of natural bone is presented, as these bone tissue microstructures and compositions are the basis for constructing bone substitutes. Next, urgent clinical issues associated with bone injury that require resolution and the potential of nanomaterials to overcome them are discussed. Finally, nanomaterials are classified as inorganic or organic based on their chemical properties. Their basic characteristics and the results of related bone engineering studies are described. This review describes theoretical and technical bases for the development of innovative methods for repairing damaged bone and should inspire therapeutic strategies with potential for clinical applications.

Sustained release of exosomes loaded into polydopamine-modified chitin conduits promotes peripheral nerve regeneration in rats

Exosomes derived from mesenchymal stem cells are of therapeutic interest because of their important role in intracellular communication and biological regulation. On the basis of previously studied nerve conduits, we designed a polydopamine-modified chitin conduit loaded with mesenchymal stem cell-derived exosomes that release the exosomes in a sustained and stable manner. In vitro experiments revealed that rat mesenchymal stem cell-derived exosomes enhanced Schwann cell proliferation and secretion of neurotrophic and growth factors, increased the expression of Jun and Sox2 genes, decreased the expression of Mbp and Krox20 genes in Schwann cells, and reprogrammed Schwann cells to a repair phenotype. Furthermore, mesenchymal stem cell-derived exosomes promoted neurite growth of dorsal root ganglia. The polydopamine-modified chitin conduits loaded with mesenchymal stem cell-derived exosomes were used to bridge 2 mm rat sciatic nerve defects. Sustained release of exosomes greatly accelerated nerve healing and improved nerve function. These findings confirm that sustained release of mesenchymal stem cell-derived exosomes loaded into polydopamine-modified chitin conduits promotes the functional recovery of injured peripheral nerves.

Brain functional remodeling caused by sciatic nerve transposition repair in rats identified by multiple-model resting-state blood oxygenation level-dependent functional magnetic resonance imaging analysis

Lower extremity nerve transposition repair has become an important treatment strategy for peripheral nerve injury; however, brain changes caused by this surgical procedure remain unclear. In this study, the distal stump of the right sciatic nerve in a rat model of sciatic nerve injury was connected to the proximal end of the left sciatic nerve using a chitin conduit. Neuroelectrophysiological test showed that the right lower limb displayed nerve conduction, and the structure of myelinated nerve fibers recovered greatly. Muscle wet weight of the anterior tibialis and gastrocnemius recovered as well. Multiple-model resting-state blood oxygenation level-dependent functional magnetic resonance imaging analysis revealed functional remodeling in multiple brain regions and the re-establishment of motor and sensory functions through a new reflex arc. These findings suggest that sciatic nerve transposition repair induces brain functional remodeling. The study was approved by the Ethics Committee of Peking University People's Hospital on December 9, 2015 (approval No. 2015-50).

The anatomical, electrophysiological and histological observations of muscle contraction units in rabbits: a new perspective on nerve injury and regeneration

In the conventional view a muscle is composed of intermediate structures before its further division into microscopic muscle fibers. Our experiments in mice have confirmed this intermediate structure is composed of the lamella cluster formed by motor endplates, the innervating nerve branches and the corresponding muscle fibers, which can be viewed as an independent structural and functional unit. In this study, we verified the presence of these muscle construction units in rabbits. The results showed that the muscular branch of the femoral nerve sent out 4–6 nerve branches into the quadriceps and the tibial nerve sent out 4–7 nerve branches into the gastrocnemius. When each nerve branch of the femoral nerve was stimulated from the most lateral to the medial, the contraction of the lateral muscle, intermediate muscle and medial muscle of the quadriceps could be induced by electrically stimulating at least one nerve branch. When stimulating each nerve branch of the tibial nerve from the lateral to the medial, the muscle contraction of the lateral muscle 1, lateral muscle 2, lateral muscle 3 and medial muscle of the gastrocnemius could be induced by electrically stimulating at least one nerve branch. Electrical stimulation of each nerve branch resulted in different electromyographical waves recorded in different muscle subgroups. Hematoxylin-eosin staining showed most of the nerve branches around the neuromuscular junctions consisted of one individual neural tract, a few consisted of two or more neural tracts. The muscles of the lower limb in the rabbit can be subdivided into different muscle subgroups, each innervated by different nerve branches, thereby allowing much more complex muscle activities than traditionally stated. Together, the nerve branches and the innervated muscle subgroups can be viewed as an independent structural and functional unit. This study was approved by the Animal Ethics Committee of Peking University People’s Hospital (approval No. 2019PHE027) on October 20, 2019.

An electroencephalography-based human-machine interface combined with contralateral C7 transfer in the treatment of brachial plexus injury

Transferring the contralateral C7 nerve root to the median or radial nerve has become an important means of repairing brachial plexus nerve injury. However, outcomes have been disappointing. Electroencephalography (EEG)-based human-machine interfaces have achieved promising results in promoting neurological recovery by controlling a distal exoskeleton to perform functional limb exercises early after nerve injury, which maintains target muscle activity and promotes the neurological rehabilitation effect. This review summarizes the progress of research in EEG-based human-machine interface combined with contralateral C7 transfer repair of brachial plexus nerve injury. Nerve transfer may result in loss of nerve function in the donor area, so only nerves with minimal impact on the donor area, such as the C7 nerve, should be selected as the donor. Single tendon transfer does not fully restore optimal joint function, so multiple functions often need to be reestablished simultaneously. Compared with traditional manual rehabilitation, EEG-based human-machine interfaces have the potential to maximize patient initiative and promote nerve regeneration and cortical remodeling, which facilitates neurological recovery. In the early stages of brachial plexus injury treatment, the use of an EEG-based human-machine interface combined with contralateral C7 transfer can facilitate postoperative neurological recovery by making full use of the brain’s computational capabilities and actively controlling functional exercise with the aid of external machinery. It can also prevent disuse atrophy of muscles and target organs and maintain neuromuscular junction effectiveness. Promoting cortical remodeling is also particularly important for neurological recovery after contralateral C7 transfer. Future studies are needed to investigate the mechanism by which early movement delays neuromuscular junction damage and promotes cortical remodeling. Understanding this mechanism should help guide the development of neurological rehabilitation strategies for patients with brachial plexus injury.

Myelin-associated glycoprotein combined with chitin conduit inhibits painful neuroma formation after sciatic nerve transection

Studies have shown that myelin-associated glycoprotein (MAG) can inhibit axon regeneration after nerve injury. However, the effects of MAG on neuroma formation after peripheral nerve injury remain poorly understood. In this study, local injection of MAG combined with nerve cap made of chitin conduit was used to intervene with the formation of painful neuroma after sciatic nerve transfection in rats. After 8 weeks of combined treatment, the autotomy behaviors were reduced in rats subjected to sciatic nerve transfection, the mRNA expression of nerve growth factor, a pain marker, in the proximal nerve stump was decreased, the density of regenerated axons was decreased, the thickness of the myelin sheath was increased, and the ratio of unmyelinated to myelinated axons was reduced. Moereover, the percentage of collagen fiber area and the percentage of fibrosis marker alpha-smooth muscle actin positive staining area in the proximal nerve stump were decreased. The combined treatment exhibited superior effects in these measures to chitin conduit treatment alone. These findings suggest that MAG combined with chitin conduit synergistically inhibits the formation of painful neuroma after sciatic nerve transection and alleviates neuropathic pain. This study was approved by the Animal Ethics Committee of Peking University People’s Hospital (approval No. 2019PHE027) on December 5, 2019.

Chitin Nerve Conduits with Three-Dimensional Spheroids of Mesenchymal Stem Cells from SD Rats Promote Peripheral Nerve Regeneration

Peripheral nerve injury (PNI) is an unresolved medical problem with limited therapeutic effects. Epineurium neurorrhaphy is an important method for treating PNI in clinical application, but it is accompanied by inevitable complications such as the misconnection of nerve fibers and neuroma formation. Conduits small gap tubulization has been proved to be an effective suture method to replace the epineurium neurorrhaphy. In this study, we demonstrated a method for constructing peripheral nerve conduits based on the principle of chitosan acetylation. In addition, the micromorphology, mechanical properties and biocompatibility of the chitin nerve conduits formed by chitosan acetylation were further tested. The results showed chitin was a high-quality biological material for constructing nerve conduits. Previous reports have demonstrated that mesenchymal stem cells culture as spheroids can improve the therapeutic potential. In the present study, we used a hanging drop protocol to prepare bone marrow mesenchymal stem cell (BMSCs) spheroids. Meanwhile, spherical stem cells could express higher stemness-related genes. In the PNI rat model with small gap tubulization, BMSCs spheres exhibited a higher ability to improve sciatic nerve regeneration than BMSCs suspension. Chitin nerve conduits with BMSCs spheroids provide a promising therapy option for peripheral nerve regeneration.

Enhanced recovery after surgery for hip fractures: a systematic review and meta-analysis

BACKGROUND

Enhanced recovery after surgery (ERAS) programs have achieved promising results in many surgical specialties. However, uncertainty still remains regarding the effect of ERAS on hip fractures. The objective of this review was to investigate the clinical prognosis of ERAS programs in terms of (1) hospital-related endpoints (time to surgery [TTS], length of stay [LOS]), (2) readmission rate, (3) complications, and (4) mortality.

METHODS

Published literature was searched in the PubMed, EMBASE, and Cochrane Library databases. All of the included studies met the inclusion criteria. The primary outcomes were TTS and LOS. The secondary outcomes included the 30-day readmission rate, overall complication rate, specific complication rate (delirium and urinary tract infection), and 30-day and 1-year mortality. Language was restricted to English. The data analysis was carried out by Review Manager 5.3.

RESULTS

A total of 7 published studies (9869 patients) were finally included, and these were all cohort studies. The meta-analysis showed that the TTS, LOS, and overall complication rate were significantly reduced in the ERAS group compared with the control group (p < 0.01). Moreover, no significant change was found in the 30-day readmission rate or 30-day and 1-year mortality.

CONCLUSIONS

ERAS significantly decreases the TTS, LOS, and complication rate without increasing readmission rate and mortality, which adds to the evidence that the implementation of ERAS is beneficial to patients undergoing hip fracture repair surgeries.

Polymer Scaffolds for Biomedical Applications in Peripheral Nerve Reconstruction

The nervous system is a significant part of the human body, and peripheral nerve injury caused by trauma can cause various functional disorders. When the broken end defect is large and cannot be repaired by direct suture, small gap sutures of nerve conduits can effectively replace nerve transplantation and avoid the side effect of donor area disorders. There are many choices for nerve conduits, and natural materials and synthetic polymers have their advantages. Among them, the nerve scaffold should meet the requirements of good degradability, biocompatibility, promoting axon growth, supporting axon expansion and regeneration, and higher cell adhesion. Polymer biological scaffolds can change some shortcomings of raw materials by using electrospinning filling technology and surface modification technology to make them more suitable for nerve regeneration. Therefore, polymer scaffolds have a substantial prospect in the field of biomedicine in future. This paper reviews the application of nerve conduits in the field of repairing peripheral nerve injury, and we discuss the latest progress of materials and fabrication techniques of these polymer scaffolds.

Combining chitin biological conduits with small autogenous nerves and platelet-rich plasma for the repair of sciatic nerve defects in rats

Aims

Peripheral nerve defects are often difficult to recover from, and there is no optimal repair method. Therefore, it is important to explore new methods of repairing peripheral nerve defects. This study explored the efficacy of nerve grafts constructed from chitin biological conduits combined with small autogenous nerves (SANs) and platelet‐rich plasma (PRP) for repairing 10‐mm sciatic nerve defects in rats.

Methods

To prepare 10‐mm sciatic nerve defects, SANs were first harvested and PRP was extracted. The nerve grafts consisted of chitin biological conduits combined with SAN and PRP, and were used to repair rat sciatic nerve defects. These examinations, including measurements of axon growth efficiency, a gait analysis, electrophysiological tests, counts of regenerated myelinated fibers and observations of their morphology, histological evaluation of the gastrocnemius muscle, retrograde tracing with Fluor‐Gold (FG), and motor endplates (MEPs) distribution analysis, were conducted to evaluate the repair status.

Results

Two weeks after nerve transplantation, the rate and number of regenerated axons in the PRP‐SAN group improved compared with those in the PRP, SAN, and Hollow groups. The PRP‐SAN group exhibited better recovery in terms of the sciatic functional index value, composite action potential intensity, myelinated nerve fiber density, myelin sheath thickness, and gastrectomy tissue at 12 weeks after transplantation, compared with the PRP and SAN groups. The results of FG retrograde tracing and MEPs analyses showed that numbers of FG‐positive sensory neurons and motor neurons as well as MEPs distribution density were higher in the PRP‐SAN group than in the PRP or SAN group.

Conclusions

Nerve grafts comprising chitin biological conduits combined with SANs and PRP significantly improved the repair of 10‐mm sciatic nerve defects in rats and may have therapeutic potential for repairing peripheral nerve defects in future applications.

Cortical plasticity and nerve regeneration after peripheral nerve injury

With the development of neuroscience, substantial advances have been achieved in peripheral nerve regeneration over the past decades. However, peripheral nerve injury remains a critical public health problem because of the subsequent impairment or absence of sensorimotor function. Uncomfortable complications of peripheral nerve injury, such as chronic pain, can also cause problems for families and society. A number of studies have demonstrated that the proper functioning of the nervous system depends not only on a complete connection from the central nervous system to the surrounding targets at an anatomical level, but also on the continuous bilateral communication between the two. After peripheral nerve injury, the interruption of afferent and efferent signals can cause complex pathophysiological changes, including neurochemical alterations, modifications in the adaptability of excitatory and inhibitory neurons, and the reorganization of somatosensory and motor regions. This review discusses the close relationship between the cerebral cortex and peripheral nerves. We also focus on common therapies for peripheral nerve injury and summarize their potential mechanisms in relation to cortical plasticity. It has been suggested that cortical plasticity may be important for improving functional recovery after peripheral nerve damage. Further understanding of the potential common mechanisms between cortical reorganization and nerve injury will help to elucidate the pathophysiological processes of nerve injury, and may allow for the reduction of adverse consequences during peripheral nerve injury recovery. We also review the role that regulating reorganization mechanisms plays in functional recovery, and conclude with a suggestion to target cortical plasticity along with therapeutic interventions to promote peripheral nerve injury recovery.

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.

Prognostic Implications of Preoperative Pneumonia for Geriatric Patients Undergoing Hip Fracture Surgery or Arthroplasty

Objective

To report outcomes of geriatric patients undergoing hip fracture surgery or arthroplasty with or without preoperative pneumonia and to evaluate the influence of pneumonia severity on patient prognosis.

Methods

In this single center retrospective study, we included geriatric patients (≥60 years old) who had undergone hip fracture surgery or arthroplasty at Peking University People's Hospital from January 2008 to September 2018. Patients with fractures caused by neoplasms or patients with incomplete clinical data were excluded. Using logistic regression and the CURB‐65 (confusion, uremia, respiratory rate, blood pressure, and age ≥65 years) score as a prediction tool of 1‐year mortality, the effect of preoperative pneumonia on 1‐year mortality was evaluated. Survival of patients with different response to pneumonia‐specific therapy and survival of patients with different pneumonia severity (evaluated with CURB‐65 score) were analyzed using Cox regression.

Results

A total of 1386 patients were included; among them, 109 patients (7.86%) were diagnosed with preoperative pneumonia. Outcomes were evaluated in August 2019 (at least 1 year after surgery for all patients). Compared to patients without preoperative pneumonia, patients with this condition had higher 30‐day mortality (11.9% vs 5%, P = 0.002) and 1‐year mortality rates (33.9% vs 16.3%, P < 0.001) and higher incidence of acute heart failure (7.3% vs 3.4%, P = 0.034) and acute kidney injury (5.5% vs 1.8%, P = 0.009). In multivariate regression, preoperative pneumonia was identified as an independent predictor of 1‐year mortality (odds ratio [OR], 1.45; 95% confidence interval [CI] 1.39–3.52; P = 0.021), with other factors including age (≥84 years, OR, 1.46; 95% CI 1.08–1.60; P = 0.027), body mass index (<18.5 kg/m², OR 2.23; 95% CI 1.52–3.17, P < 0.001), anesthesia type (regional, OR 0.87; 95% CI 0.19–0.97, P = 0.042), preoperative pneumonia (OR 1.45; 95% CI 1.39–3.52; P = 0.002), congestive heart failure (OR 2.05, 95% CI 1.57–6.21, P < 0.001), chronic kidney disease (OR 1.73; 95% CI 1.50–2.62; P < 0.001). There was a trend of increased 1‐year mortality as the CURB‐65 score elevated (P for trend = 0.006). Cox regression reveals a higher risk of mortality in patient with preoperative pneumonia, especially in patients with no radiologic improvements after therapy (log‐rank, P = 0.035). Analysis of the impact of pneumonia severity on patient survival using Cox regression reveals that a CURB‐65 score ≥3 indicated a lower rate of survival (CURB‐65 score of 3: hazard ratio [HR] 3.12, 95% CI 1.39–7.03, P = 0.006; score of 4: HR 3.41, 95% CI 1.69–6.92, P = 0.001; score of 5: HR 6.28, 95% CI 2.95–13.35, P < 0.001).

Conclusion

In this single center retrospective study, preoperative pneumonia was identified as an independent risk factor of 1‐year mortality in geriatric patients undergoing hip fracture surgery or arthroplasty. A CURB‐65 score ≥3 indicated a higher risk of mortality.

[Expression and significance of PD-1 and PD-L1 in the specimens of epithelial ovarian cancer]

Objective: To examine the expression of programmed cell death 1 (PD-1) and its ligand (PD-L1) in epithelial ovarian cancer (EOC) tissues, and investigate the correlation among their expression, clinicopathological features and prognosis. Methods: The specimens of 180 patients with EOC treated in the First Affiliated Hospital of Dalian Medical University from October 2002 to December 2013 were confirmed by pathological examination. The pathological tissue specimens of subtypes ，included 120 cases of serous carcinoma, 30 cases of mucinous carcinoma, 20 cases of endometrioid carcinoma, and 20 cases of clear cell carcinoma. The normal paracancerous tissues of 50 cases randomly selected from the 180 patients as control group. Immunohistochemical SP method was used to detect the expressions of both PD-1 and PD-L1 in epithelial ovarian cancer tissues, and the relationships among their expressions,the clinicopathological parameters and prognosis were respectively analyzed. Results: （1） PD-1 was expressed in lymphocytes infiltrated in EOC tissues, and PD-L1 was expressed in the cell membranes of cancer tissues. In all EOC cases, 33 cases (18.3%, 33/180) of both PD-1 and PD-L1 were highly expressed, and only 1 (2.0%, 1/50) of control group showed high expression. There was statistically significant difference between two groups (P<0.01). (2) Among the four subtypes tissue specimens of EOC, the high expression rate of PD-1 was 25.0% (30/120) for serous carcinoma, 3/15 for endometrioid carcinoma, 0 (0/30) for mucinous carcinoma, and 0 (0/15) for clear cell carcinoma. The high expression rate of PD-L1 was 23.3% (28/120) for serous carcinoma, 3.3% (1/30) for mucinous carcinoma, 2/15 for endometrioid carcinoma, and 2/15 for clear cell carcinoma. Both PD-1 and PD-L1 expressions in the four sub-types of tissue specimens were significantly different (P<0.05). The high expression rate of both PD-1 and PD-L1 was 9.2% (8/87) in the early stage and 26.9% (25/93) in the late stage. There was a statistically significant difference between the two groups (P<0.01). Similarly, the expression of both PD-1 and PD-L1 were significantly higher in the cases of high-grade EOC （type Ⅱ） than those of low-grade （type Ⅰ） and in the cases of EOC distributed bilaterally than that distributed unilaterally, and there were statistically significant differences (P<0.05). (3) The Kaplan-Meier survival analysis showed that the survival time were respectively 35 and 36 months in the cases with high expressions of both PD-1 and PD-L1, and the survival time were the same as 61 months in the cases with low expression of both PD-1 and PD-L1, and the comparison was statistically significant (P<0.05). Conclusions: The expression levels of PD-1 and PD-L1 in EOC tissues are higher than those in adjacent tissues, especially in serous carcinomas. The expression of both PD-1 and PD-L1 is higher in specimens of the patients with advanced stages. The results showed that the high expression of both PD-1 and PD-L1 is an indicator of poor prognosis of patients suffering from EOC.

Hip Replacement as Alternative to Intramedullary Nail in Elderly Patients with Unstable Intertrochanteric Fracture: A Systematic Review and Meta-Analysis

Objective

To evaluate the efficacy and safety of hip replacement and intramedullary nails for treating unstable intertrochanteric fractures in elderly patients.

Methods

Randomized clinical trials (RCTs) to compare hip replacement with intramedullary nail in the management of elderly patients with unstable intertrochanteric femur fracture were retrieved from Cochrane Library (up to January 2018), CNKI (China National Knowledge Infrastructure), Wanfang Data, PubMed, and Embase. The methodological quality of the included trials was assessed using the Cochrane risk of bias assessment tool, and relevant data was extracted. Statistical analysis was performed by Revman 5.3. Where possible, we performed the limited pooling of data.

Results

Fourteen trials including a total of 1067 participants aged 65 and above were included for qualitative synthesis and meta‐analysis. The methodological quality of the included study was poor. The meta‐analysis indicated that the hip replacement group benefited more than the intramedullary nail group in terms of the bearing load time (WMD ‐14.61, 95% CI −21.51 to −7.7, P < 0.0001), mechanical complications (OR 0.34, 95% CI 0.21 to 0.57, P < 0.0001), and post‐operative complications (OR 0.46, 95% CI 0.22 to 0.93, P = 0.03). While the intramedullary nail was superior to arthroplasty regarding the intraoperative blood loss (WMD 58.36, 95% CI 30.77 to 85.94, P < 0.0001). However, there were no statistical significances in the length of surgery (WMD 5.27, 95% CI 4.23 to 14.77, P = 0.28), units of blood transfusion (WMD 0.34, 95% CI ‐0.16 to 0.85, P = 0.18), length of hospital stay (WMD ‐1.00, 95% CI ‐2.93 to 0.93, P = 0.31), Harris hip score (WMD 0.31, 95% CI ‐0.39 to 1.01, P = 0.38), and mortality (OR 1.24, 95% CI 0.12 to 13.10, P = 0.86).

Conclusions

This systematic review and meta‐analysis provided evidence for the efficacy and safety of hip replacement and intramedullary nail in treating unstable intertrochanteric fractures. However, the results should be interpreted cautiously because of methodological limitations and publication bias.

Risk Factors for Functional Outcomes of the Elderly with Intertrochanteric Fracture: A Retrospective Cohort Study

Objective

To identify baseline factors relevant to functional outcomes and health‐related quality of life in the elderly with intertrochanteric fractures.

Methods

For the present study, 168 patients with intertrochanteric fracture who were assigned to different treatments between January 2016 and December 2017 were retrospectively selected. Hip function was assessed by Harris hip score (HHS), and health‐related quality of life was evaluated by Barthel index (BI) of activities of daily living (ADL) and EuroQol 5‐dimensions (EQ‐5D) score, respectively. Data were analyzed by t‐test, ANOVA, Pearson's correlation, χ²‐test, and multivariate linear regression.

Results

A total of 164 (97.6%) patients completed the follow‐up, with an average follow‐up time of 15.7 ± 6.9 months; 39 (23.8%) patients died during the follow‐up period and 125 (76.2%) patients were eligible for the functional analysis. HHS at final follow‐up of 125 patients was 71.8 ± 13.1, and the following were associated with hip functional recovery: age (−0.45, 95% confidence interval (CI) −0.73 to −0.18, P < 0.01), serum albumin (0.65, 95% CI 0.04 to 1.27, P < 0.05), and ADL at discharge (0.18, 95% CI 0.01 to 0.33, P < 0.05). The Barthel index at final follow up in this cohort was 80.2 ± 18.1, and multivariable linear regression analysis showed that age (−0.49, 95% CI −0.85 to −0.12; P < 0.05), ADL score at discharge (0.29, 95% CI 0.07 to 0.51; P < 0.05) and internal fixation (16.3, 95% CI 3.3 to 29.3; P < 0.05) were associated with ADL at final follow‐up. EQ‐5D at final follow‐up was 0.74 ± 0.2, with which HHS (0.012, 95% CI 0.011 to 0.013; P < 0.01) was positively associated.

Conclusion

We identify several baseline factors associated with hip functional outcome, health utility, and ADL in the elderly after an intertrochanteric fracture, of which we could modify mutable factors to achieve better outcomes. These findings could help to inform treatment and functional prognosis.

[Expression and significance of MAPK/ERK in the specimens and cells of epithelial ovarian cancer]

Objective: To detect phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) protein expression in epithelial ovarian cancer and cell lines, and to examine the effects of mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor AZD6244 on cell proliferation, apoptosis as well as cell cycle of ovarian cancer cells. To explore the function and significance of MAPK/extracellular signal-regulated kinase (ERK) signaling pathway in the development of ovarian cancer. Methods: (1) A total of 104 cases of patients with ovarian cancer who accepted the treatment of gynecological surgery and being confirmed by pathological examination in First Affiliated Hospital, Dalian Medical University from January 2004 to December 2013 were selected. The expressions of p-ERK1/2 protein were detected by immunohistochemistry in ovarian cancer specimens, and the relationship between the expressions of p-ERK1/2 and the clinical features of patients was analyzed. (2) p-ERK1/2 and other related proteins were determined by western blot in various ovarian cancer cells, including SKOV3, OV2008, C13, A2780S, A2780CP, OVCAR4, OVCAR5, OVCAR8 and CAOV3 treated with or without MEK inhibitor. The cellular proliferation, apoptosis and cell cycle of ovarian cancer cells after treatment with MEK inhibitor were analyzed by methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively. Results: (1) The immunohistochemical method showed that p-ERK1/2 between low grade serous carcinoma and clear cell carcinoma were not significantly higher expressed (P>0.05) . However, a lower level of the p-ERK1/2 expression were observed among high grade serous carcinoma, mucinous carcinoma and endometrioid carcinoma (all P<0.05) . There was no significant correlation between the protein expression of p-ERK1/2 and patients' age, pathological stage of surgery, and preoperative serum CA(125) level (P>0.05). (2) Western blot showed that the protein p-ERK1/2 was widely expressed in various ovarian cancer cell lines such as SKOV3, OV2008, C13, A2780S, A2780CP, OVCAR4, OVCAR5, OVCAR8 and CAOV3. After treatment with AZD6244 (5, 10 μmol/L), the level of p-ERK1/2 in OVCAR5 and OVCAR8 decreased significantly in dose-dependent manner. Additionally, we found a reduction of the expression level of cyclin D1, caspase-3 and appeared cleaved poly adenosine diphosphate ribose polymerase (PARP) in OVCAR5 and OVCAR8, compared with control groups. MTT assays showed that OVCAR5, OVCAR8 and A2780S were differently inhibited in the dose-dependent manner after being treated with different concentrations of AZD6244 (0, 2.5, 5, 10, 25, 50 and 100 μmol/L, all P<0.05). Further tested by flow cytometry, the results showed that AZD6244 (5, 10 μmol/L) was able to induce the apoptosis of OVCAR5, OVCAR8 and A2780S, as well as G(0)/G(1) phase arrest, both in a dose-dependent manner (P<0.05). Conclusions: As the main active and functional unit of MAPK/ERK signaling pathway, p-ERK1/2 protein is expressed in both the tissues and various ovarian cancer cell lines. AZD6244 could down-regulated the expression of p-ERK1/2 in ovarian cancer cells, accompanied by the decreased proliferation and increased cell apoptosis of ovarian cancer cells. In conclusion, MAPK/ERK signaling pathway might play a role in the development and progression of ovarian cancer, and may be provide a novel option for molecular targeted therapies of the disease.

[Analysis of prophylactic effect of extended-duration anticoagulant drugs in elderly patients undergoing hip fracture]

OBJECTIVE

To evaluate the prophylactic effect of extended-duration anticoagulant drugs on venous thromboembolism, and to explore the time of drug prevention for venous thromboembolism after hip fracture.

METHODS

A retrospective analysis of 143 patients undergoing hip fractures from November 2017 to October 2018 in Peking University People's Hospital was conducted to investigate the relationship between the extended-duration anticoagulant drug and the morbidity of venous thromboembolism and bleeding during the treatment. All the drug prevention programs for the patients included in the study were implemented in accordance with the 2016 edition of the Guidelines for Prevention of Venous Thrombosis in Orthopaedic Surgery by Orthopaedic Society of Chinese Medical Association. The patients in the two groups were followed up for venous thromboembolism and bleeding during the medication within 5 weeks after the fracture. Venous thromboembolism included symptomatic and asymptomatic deep venous thrombosis of the lower extremities, pulmonary thromboembolism, and all the patients with deep venous thrombosis of the lower extremities required vascular ultrasound results to obtain clear evidence. The results of vascular ultrasound were the basis for determining deep venous thrombosis. Bleeding conditions were included, but not limited to gastrointestinal bleeding, wound bleeding, intracranial hemorrhage, intraspinal hematoma, and fundus hemorrhage.

RESULTS

There were no pulmonary thromboembolism in both groups after surgery. The morbidity of deep venous thrombosis was 22.09% and 8.77% in the 2-week and 4-week groups (P=0.037), the time to deep venous thrombosis in the two groups was (17.32±7.75) days and (29.20±0.17) days after surgery. One case of bleeding occurred during the use of anticoagulant drugs in both groups, the morbidity of bleeding during the treatment was 1.16% and 1.75% (P=0.769), respectively.

CONCLUSION

Extended-duration anticoagulant drugs to 4 weeks after surgery can significantly reduce the morbidity of postoperative venous thromboembolism, and does not increase the risk of bleeding. Patients with a risk of bleeding should carefully assess the risks and benefits of drug prevention and choose the best treatment.

Qian-Zheng-San promotes regeneration after sciatic nerve crush injury in rats

Qian-Zheng-San, a traditional Chinese prescription consisting of Typhonii Rhizoma, Bombyx Batryticatus, Scorpio, has been found to play an active therapeutic role in central nervous system diseases. However, it is unclear whether Qian-Zheng-San has therapeutic value for peripheral nerve injury. Therefore, we used Sprague-Dawley rats to investigate this. A sciatic nerve crush injury model was induced by clamping the right sciatic nerve. Subsequently, rats in the treatment group were administered 2 mL Qian-Zheng-San (1.75 g/mL) daily as systemic therapy for 1, 2, 4, or 8 weeks. Rats in the control group were not administered Qian-Zheng-San. Rats in sham group did not undergo surgery and systemic therapy. Footprint analysis was used to assess nerve motor function. Electrophysiological experiments were used to detect nerve conduction function. Immunofluorescence staining was used to assess axon counts and morphological analysis. Immunohistochemical staining was used to observe myelin regeneration of the sciatic nerve and the number of motoneurons in the anterior horn of the spinal cord. At 2 and 4 weeks postoperatively, the sciatic nerve function index, nerve conduction velocity, the number of distant regenerated axons and the axon diameter of the sciatic nerve increased in the Qian-Zheng-San treatment group compared with the control group. At 2 weeks postoperatively, nerve fiber diameter, myelin thickness, and the number of motor neurons in the lumbar spinal cord anterior horn increased in the Qian-Zheng-San treatment group compared with the control group. These results indicate that Qian-Zheng-San has a positive effect on peripheral nerve regeneration.

Reinnervation of spinal cord anterior horn cells after median nerve repair using transposition with other nerves

Our previous studies have confirmed that during nerve transposition repair to injured peripheral nerves, the regenerated nerve fibers of motor neurons in the anterior horn of the spinal cord can effectively repair distal nerve and target muscle tissue and restore muscle motor function. To observe the effect of nerve regeneration and motor function recovery after several types of nerve transposition for median nerve defect (2 mm), 30 Sprague-Dawley rats were randomly divided into sham operation group, epineurial neurorrhaphy group, musculocutaneous nerve transposition group, medial pectoral nerve transposition group, and radial nerve muscular branch transposition group. Three months after nerve repair, the wrist flexion test was used to evaluate the recovery of wrist flexion after regeneration of median nerve in the affected limbs of rats. The number of myelinated nerve fibers, the thickness of myelin sheath, the diameter of axons and the cross-sectional area of axons in the proximal and distal segments of the repaired nerves were measured by osmic acid staining. The ratio of newly produced distal myelinated nerve fibers to the number of proximal myelinated nerve fibers was calculated. Wet weights of the flexor digitorum superficialis muscles were measured. Muscle fiber morphology was detected using hematoxylin-eosin staining. The cross-sectional area of muscle fibers was calculated to assess the recovery of muscles. Results showed that wrist flexion function was restored, and the nerve grew into the distal effector in all three nerve transposition groups and the epineurial neurorrhaphy group. There were differences in the number of myelinated nerve fibers in each group. The magnification of proximal to distal nerves was 1.80, 3.00, 2.50, and 3.12 in epineurial neurorrhaphy group, musculocutaneous nerve transposition group, medial pectoral nerve transposition group, and radial nerve muscular branch transposition group, respectively. Nevertheless, axon diameters of new nerve fibers, cross-sectional areas of axons, thicknesses of myelin sheath, wet weights of flexor digitorum superficialis muscle and cross-sectional areas of muscle fibers of all three groups of donor nerves from different anterior horn motor neurons after nerve transposition were similar to those in the epineurial neurorrhaphy group. Our findings indicate that donor nerve translocation from different anterior horn motor neurons can effectively repair the target organs innervated by the median nerve. The corresponding spinal anterior horn motor neurons obtain functional reinnervation and achieve some degree of motor function in the affected limbs.

Repair of long segmental ulnar nerve defects in rats by several different kinds of nerve transposition

Multiple regeneration of axonal buds has been shown to exist during the repair of peripheral nerve injury, which confirms a certain repair potential of the injured peripheral nerve. Therefore, a systematic nerve transposition repair technique has been proposed to treat severe peripheral nerve injury. During nerve transposition repair, the regenerated nerve fibers of motor neurons in the anterior horn of the spinal cord can effectively grow into the repaired distal nerve and target muscle tissues, which is conducive to the recovery of motor function. The aim of this study was to explore regeneration and nerve functional recovery after repairing a long-segment peripheral nerve defect by transposition of different donor nerves. A long-segment (2 mm) ulnar nerve defect in Sprague-Dawley rats was repaired by transposition of the musculocutaneous nerve, medial pectoral nerve, muscular branches of the radial nerve and anterior interosseous nerve (pronator quadratus muscle branch). In situ repair of the ulnar nerve was considered as a control. Three months later, wrist flexion function, nerve regeneration and innervation muscle recovery in rats were assessed using neuroelectrophysiological testing, osmic acid staining and hematoxylin-eosin staining, respectively. Our findings indicate that repair of a long-segment ulnar nerve defect with different donor nerve transpositions can reinnervate axonal function of motor neurons in the anterior horn of spinal cord and restore the function of affected limbs to a certain extent.

Repair of peripheral nerve defects by nerve transposition using small gap bio-sleeve suture with different inner diameters at both ends

During peripheral nerve transposition repair, if the diameter difference between transposed nerves is large or multiple distal nerves must be repaired at the same time, traditional epineurial neurorrhaphy has the problem of high tension at the suture site, which may even lead to the failure of nerve suture. We investigated whether a small gap bio-sleeve suture with different inner diameters at both ends can be used to repair a 2-mm tibial nerve defect by proximal transposition of the common peroneal nerve in rats and compared the results with the repair seen after epineurial neurorrhaphy. Three months after surgery, neurological function, nerve regeneration, and recovery of nerve innervation muscle were assessed using the tibial nerve function index, neuroelectrophysiological testing, muscle biomechanics and wet weight measurement, osmic acid staining, and hematoxylin-eosin staining. There was no obvious inflammatory reaction and neuroma formation in the tibial nerve after repair by the small gap bio-sleeve suture with different inner diameters at both ends. The conduction velocity, muscle strength, wet muscle weight, cross-sectional area of muscle fibers, and the number of new myelinated nerve fibers in the bio-sleeve suture group were similar to those in the epineurial neurorrhaphy group. Our findings indicate that small gap bio-sleeve suture with different inner diameters at both ends can achieve surgical suture between nerves of different diameters and promote regeneration and functional recovery of injured peripheral nerves.

Tissue engineering for the repair of peripheral nerve injury

Peripheral nerve injury is a common clinical problem and affects the quality of life of patients. Traditional restoration methods are not satisfactory. Researchers increasingly focus on the field of tissue engineering. The three key points in establishing a tissue engineering material are the biological scaffold material, the seed cells and various growth factors. Understanding the type of nerve injury, the construction of scaffold and the process of repair are necessary to solve peripheral nerve injury and promote its regeneration. This review describes the categories of peripheral nerve injury, fundamental research of peripheral nervous tissue engineering and clinical research on peripheral nerve scaffold material, and paves a way for related research and the use of conduits in clinical practice.

Treatment of unstable distal clavicle fractures (Neer type II): A comparison of three internal fixation methods

OBJECTIVE

This study was performed to compare the clinical efficacy of three internal fixation methods for distal clavicle fractures (Neer type II): clavicular hook plate (Group A), anatomical plate (Group B), and arthroscopic Endobutton (Group C).

METHODS

From 2001 to 2014, 58 patients with Neer type II distal clavicle fractures were treated at our institution. The clinical results were assessed with the visual analog scale (VAS), Constant score, and Simple Shoulder Test (SST) score.

RESULTS

All patients had anatomic reduction and bone healing at the final follow-up. Groups B and C had considerably less intraoperative blood loss than Group A. The incision was significantly shorter in Group C than in Groups A and B. The mean VAS score was significantly higher in the affected than unaffected shoulder. The Constant and SST scores were significantly higher in the unaffected than affected shoulder. The VAS, Constant, and SST scores of the affected shoulders were not significantly different among the three groups.

CONCLUSIONS

Arthroscopic Endobutton fixation has long-term clinical results similar to those of other surgical protocols for distal clavicle fractures (Neer type II). We recommend this technique because of less blood loss, shorter incision length, and less shoulder irritation than other methods.

Prognostic significance of downregulated BMAL1 and upregulated Ki-67 proteins in nasopharyngeal carcinoma

This study assessed the prognostic value of BMAL1 and Ki-67 expression in patients with nasopharyngeal carcinoma. Level of BMAL1 mRNA was assessed in tissue specimens from 36 nasopharyngeal carcinomas and 20 nasopharyngeal chronic inflammations using quantitative reverse transcriptase-polymerase chain reaction. Expression of BMAL1 and Ki-67 proteins was analyzed immunohistochemically in 90 paired nasopharyngeal carcinoma and distant normal tissues. The Kaplan-Meier curves and the Log-rank test were used to calculate prognostic significance stratified by BMAL1 and Ki67 protein expression and the COX regression model was to analyze the multivariate prognosis. BMAL1 mRNA was significantly reduced in nasopharyngeal carcinoma (4.67 ± 0.27 versus 6.64 ± 0.51 in chronic inflammation tissues, p = 0.002). Level of BMAL1 mRNA was associated with tumor distant metastasis (3.37 ± 0.66 versus 5.04 ± 0.27 compared with non-metastasis, p = 0.011). Level of BMAL1 protein was also reduced in tumor tissues and BMAL1 expression was associated with better 1-, 3- and 5-year overall survival (OS) of cancer patients (92.6%, 69.2% and 62.3% versus 59.1%, 40.9% and 0% in patients with low BMAL1 expressed tumors; p = 0.000). BMAL1 expression and age were independent prognostic factors for OS (p = 0.032). Furthermore, Ki-67 expression was high in tumor versus normal tissues and associated with poor OS of cancer patients (p = 0.035). The Pearson correlation analysis showed that there was an inverse association between BMAL1 and Ki-67 protein expression (p = 0.021). This study demonstrated that lost BMAL1 and Ki-67 overexpression were associated with poor OS of nasopharyngeal carcinoma patients.

Chitin biological absorbable catheters bridging sural nerve grafts transplanted into sciatic nerve defects promote nerve regeneration

AIMS

To investigate the efficacy of chitin biological absorbable catheters in a rat model of autologous nerve transplantation.

METHODS

A segment of sciatic nerve was removed to produce a sciatic nerve defect, and the sural nerve was cut from the ipsilateral leg and used as a graft to bridge the defect, with or without use of a chitin biological absorbable catheter surrounding the graft. The number and morphology of regenerating myelinated fibers, nerve conduction velocity, nerve function index, triceps surae muscle morphology, and sensory function were evaluated at 9 and 12 months after surgery.

RESULTS

All of the above parameters were improved in rats in which the nerve graft was bridged with chitin biological absorbable catheters compared with rats without catheters.

CONCLUSIONS

The results of this study indicate that use of chitin biological absorbable catheters to surround sural nerve grafts bridging sciatic nerve defects promotes recovery of structural, motor, and sensory function and improves muscle fiber morphology.

Oxidative stress induced necroptosis activation is involved in the pathogenesis of hyperoxic acute lung injury

Necroptosis has been found to be involved in the pathogenesis of some lung diseases, but its role in hyperoxic acute lung injury (HALI) is still unclear. This study aimed to investigate contribution of necroptosis to the pathogenesis of HALI induced by hyperbaric hyperoxia exposure in a rat model. Rats were divided into control group, HALI group, Nec-1 (necroptosis inhibitor) group and edaravone group. Rats were exposed to pure oxygen at 250 kPa for 6 h to induce HALI. At 30 min before hyperoxia exposure, rats were intraperitoneally injected with Nec-1 or edaravone, and sacrificed at 24 h after hyperoxia exposure. Lung injury was evaluated by histology, lung water to dry ratio (W/D) and bronchoalveolar lavage fluid (BALF) biochemistry; the serum and plasma oxidative stress, expression of RIP1, RIP3 and MLKL, and interaction between RIP1 and RIP3 were determined. Results showed hyperoxia exposure significantly caused damage to lung and increased necroptotic cells and the expression of RIP1, RIP3 and MLKL. Edaravone pre-treatment not only inhibited the oxidative stress in HALI, but also reduced necroptotic cells, decreased the expression of RIP1, RIP3 and MLKL and improved lung pathology. Nec-1 pretreatment inhibited necroptosis and improved lung pathology, but had little influence on oxidative stress. This study suggests hyperoxia exposure induces oxidative stress may activate necroptosis, involving in the pathology of HALI, and strategies targeting necroptosis may become promising treatments for HALI.

Short-term observations of the regenerative potential of injured proximal sensory nerves crossed with distal motor nerves

Motor nerves and sensory nerves conduct signals in different directions and function in different ways. In the surgical treatment of peripheral nerve injuries, the best prognosis is obtained by keeping the motor and sensory nerves separated and repairing the nerves using the suture method. However, the clinical consequences of connections between sensory and motor nerves currently remain unknown. In this study, we analyzed the anatomical structure of the rat femoral nerve, and observed the motor and sensory branches of the femoral nerve in the quadriceps femoris. After ligation of the nerves, the proximal end of the sensory nerve was connected with the distal end of the motor nerve, followed by observation of the changes in the newly-formed regenerated nerve fibers. Acetylcholinesterase staining was used to distinguish between the myelinated and unmyelinated motor and sensory nerves. Denervated muscle and newly formed nerves were compared in terms of morphology, electrophysiology and histochemistry. At 8 weeks after connection, no motor nerve fibers were observed on either side of the nerve conduit and the number of nerve fibers increased at the proximal end. The proportion of newly-formed motor and sensory fibers was different on both sides of the conduit. The area occupied by autonomic nerves in the proximal regenerative nerve was limited, but no distinct myelin sheath was visible in the distal nerve. These results confirm that sensory and motor nerves cannot be effectively connected. Moreover, the change of target organ at the distal end affects the type of nerves at the proximal end.

[Morphology character and reduction methods of sagittally unstable intertrochanteric fractures]

OBJECTIVE

To investigate the morphology character of sagittally unstable intertrochanteric fractures and reduction methods.

METHODS

A retrospective study was used to analyze the clinical data of sagittally unstable intertrochanteric fractures cases, which were treated with proximal femoral nail anti-rotation (PFNA) fixation from March 2009 to June 2016. In the study, 36 cases were followed up completely, in which 17 cases accepted open reduction, and the other 19 cases accepted minimally invasive reduction. The operation time, amount of bleeding, the fluoroscopy times, postoperative radiographic measurements, such as tip-apex distance (TAD) and sliding distance of the spiral screw, and hip Harris scores were analyzed. The morphology character of the fractures was documented and investigated.

RESULTS

The average follow-up time was 15 months. The amount of bleeding of the open reduction group was (170.5±19.7) mL, and the amount of bleeding of the minimally invasive group was (54.7±12.5) mL. The amount of bleeding of the minimally invasive group was significantly less than that of the open reduction group (P<0.001). Between the two groups, there were no significant differences in other evaluation parameter, including operation time (P=0.054), the fluoroscopy times (P=0.053), fracture healing time (P=0.305), postoperative radiographic measurements, such as TAD (P=0.317) and sliding distance of the spiral screw (P=0.206), and hip Harris scores (P=0.459). In regard to morphology character of the fractures, the proximal anterior unstable fractures with separation displacement were more common than the proximal posterior unstable fractures with impaction. The characteristic feature of the proximal anterior unstable fractures was the proximal anterior and medial long oblique fracture, and a V shape cortical defect in the distal fracture fragment on the externally rotation X-ray.

CONCLUSION

Sagittally unstable intertrochanteric fractures can be divided into the proximal anterior unstable fractures with separation displacement, and the proximal posterior unstable fractures with impaction. The two types have their own morphology character individually. The reduction should be performed by minimally invasive techniques.

Autologous transplantation with fewer fibers repairs large peripheral nerve defects

Peripheral nerve injury is a serious disease and its repair is challenging. A cable-style autologous graft is the gold standard for repairing long peripheral nerve defects; however, ensuring that the minimum number of transplanted nerve attains maximum therapeutic effect remains poorly understood. In this study, a rat model of common peroneal nerve defect was established by resecting a 10-mm long right common peroneal nerve. Rats receiving transplantation of the common peroneal nerve in situ were designated as the in situ graft group. Ipsilateral sural nerves (10–30 mm long) were resected to establish the one sural nerve graft group, two sural nerves cable-style nerve graft group and three sural nerves cable-style nerve graft group. Each bundle of the peroneal nerve was 10 mm long. To reduce the barrier effect due to invasion by surrounding tissue and connective-tissue overgrowth between neural stumps, small gap sleeve suture was used in both proximal and distal terminals to allow repair of the injured common peroneal nerve. At three months postoperatively, recovery of nerve function and morphology was observed using osmium tetroxide staining and functional detection. The results showed that the number of regenerated nerve fibers, common peroneal nerve function index, motor nerve conduction velocity, recovery of myodynamia, and wet weight ratios of tibialis anterior muscle were not significantly different among the one sural nerve graft group, two sural nerves cable-style nerve graft group, and three sural nerves cable-style nerve graft group. These data suggest that the repair effect achieved using one sural nerve graft with a lower number of nerve fibers is the same as that achieved using the two sural nerves cable-style nerve graft and three sural nerves cable-style nerve graft. This indicates that according to the ‘multiple amplification’ phenomenon, one small nerve graft can provide a good therapeutic effect for a large peripheral nerve defect.

Renin-angiotensin system and its role in hyperoxic acute lung injury

Oxygen is essential to sustain life, but at a high partial pressure oxygen may cause toxicity to the human body. These injuries to the lung are known as hyperoxic acute lung injury [HALI]). To date, numerous studies have been conducted to investigate the pathogenesis of HALI, for which some hypotheses have been proposed. Accumulating evidence indicates that the renin-angiotensin system (RAS) plays an important role in the pathogenesis of some lung diseases, including acute lung injury (ALI), chronic obstructive pulmonary disease (COPD) and HALI. In this review, we briefly introduce the classic RAS, local (tissue) RAS and intracellular RAS, and we summarize findings on the relationship between local/classic RAS and HALI. The importance--and ambiguity--of the results of these studies indicate a need for further investigations of the RAS and its role in the patho- genesis of HALI.

[Clinical auxiliary diagnosis value of high frequency ultrasonographic measurements of the thickness of transverse carpal ligaments in carpal tunnel syndrome patients]

OBJECTIVE

To evaluate the meaning and value of high-frequency ultrasound in the diagnosis of carpal tunnel syndrome (CTS).

METHODS

In this study, 48 patients (unilateral hand) with CTS were analyzed. The thickness of transverse carpal ligaments at the pisiform bone was measured using high-frequency ultrasound. Open carpal tunnel release procedure was performed in the 48 CTS patients, and the thickness of transverse carpal ligaments at the hamate hook bone measured using vernier caliper under direct vision. The accuracy of thickness of transverse carpal ligaments was evaluated using high-frequency ultrasound. high-frequency ultrasound measurement of thickness of transverse carpal ligaments at the hamate hook bone and pisiform bone, and determination of the diagnostic threshold measurement index using receiver operating characteristic (ROC) curve, sensitivity and specificity were performed and the correlation between the thickness of transverse carpal ligaments and nerve conduction study (NCS) analyzed.

RESULTS

The thickness of transverse carpal ligaments in the CTS patients were (0.42±0.08) cm (high-frequency ultrasound) and (0.41±0.06) cm (operation) at hamate hook bone, and there was no significant difference between the two ways (t=0.672, P>0.05). The optimal cut-off value of the transverse carpal ligaments at hamate hook bone was 0.385 cm, the sensitivity 0.775, and the specificity 0.788. The optimal cut-off value of the transverse carpal ligaments at the pisiform bone was 0.315 cm, the sensitivity 0.950, and the specificity 1.000. The transverse carpal ligaments thickness and wrist-index finger sensory nerve conduction velocity (SCV), wrist-middle finger SCV showed a negative correlation.

CONCLUSION

High frequency ultrasound measurements of thickness of transverse carpal ligaments is a valuable method for the diagnosis of CTS.

Evaluation of the effects of standard rescue procedure on severe trauma treatment in china

Background:

This study aimed to evaluate the effects of standard rescue procedure (SRP) in improving severe trauma treatments in China.

Methods:

This study was conducted in 12 hospitals located in geographically and industrially different cities in China. A standard procedure on severe trauma rescue was established as a general rule for staff training and patient treatment. A regional network (system) efficiently integrating prehospital rescue, emergency room treatments, and hospital specialist treatments was built under the rule for information sharing and improving severe trauma treatments. Treatment outcomes were compared between before and 1 year after the implementation of the SRP.

Results:

The outcomes of a total of 74,615 and 12,051 trauma cases were collected from 12 hospitals before and after the implementation of the SRP. Implementation of the SRP led to efficient cooperation and information sharing of different treatment services. The emergency response time, prehospital transit time, emergency rescue time, consultation call time, and mortality rate of patients were 24.24 ± 4.32 min, 45.69 ± 3.89 min, 6.38 ± 1.05 min, 17.53 ± 0.72 min, and 33.82% ± 3.87% (n = 441), respectively, before the implementation of the standardization and significantly reduced to 10.11 ± 3.21 min, 22.39 ± 4.32 min, 3.26 ± 0.89 min, 3.45 ± 0.45 min, and 20.49% ± 3.11%, separately (n = 495, P < 0.05) after that.

Conclusions:

Staff training and SRP can significantly improve the efficiency of severe trauma treatments in China.

Comparison of commonly used retrograde tracers in rat spinal motor neurons

The purpose of this study was to investigate the effect of four fluorescent dyes, True Blue (TB), Fluoro-Gold (FG), Fluoro-Ruby (FR), and 1,1’-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI), in retrograde tracing of rat spinal motor neurons. We transected the muscle branch of the rat femoral nerve and applied each tracer to the proximal stump in single labeling experiments, or combinations of tracers (FG-DiI and TB-DiI) in double labeling experiments. In the single labeling experiments, significantly fewer labeled motor neurons were observed after FR labeling than after TB, FG, or DiI, 3 days after tracer application. By 1 week, there were no significant differences in the number of labeled neurons between the four groups. In the double-labeling experiment, the number of double-labeled neurons in the FG-DiI group was not significantly different from that in the TB-DiI group 1 week after tracer application. Our findings indicate that TB, FG, and DiI have similar labeling efficacies in the retrograde labeling of spinal motor neurons in the rat femoral nerve when used alone. Furthermore, combinations of DiI and TB or FG are similarly effective. Therefore, of the dyes studied, TB, FG and DiI, and combinations of DiI with TB or FG, are the most suitable for retrograde labeling studies of motor neurons in the rat femoral nerve.

Anterior subcutaneous transposition of the ulnar nerve improves neurological function in patients with cubital tunnel syndrome

Although several surgical procedures exist for treating cubital tunnel syndrome, the best surgical option remains controversial. To evaluate the efficacy of anterior subcutaneous transposition of the ulnar nerve in patients with moderate to severe cubital tunnel syndrome and to analyze prognostic factors, we retrospectively reviewed 62 patients (65 elbows) diagnosed with cubital tunnel syndrome who underwent anterior subcutaneous transposition. Preoperatively, the initial severity of the disease was evaluated using the McGowan scale as modified by Goldberg: 18 patients (28%) had grade IIA neuropathy, 20 (31%) had grade IIB, and 27 (42%) had grade III. Postoperatively, according to the Wilson & Krout criteria, treatment outcomes were excellent in 38 patients (58%), good in 16 (25%), fair in 7 (11%), and poor in 4 (6%), with an excellent and good rate of 83%. A negative correlation was found between the preoperative McGowan grade and the postoperative Wilson & Krout score. The patients having fair and poor treatment outcomes had more advanced age, lower nerve conduction velocity, and lower action potential amplitude compared with those having excellent and good treatment outcomes. These results suggest that anterior subcutaneous transposition of the ulnar nerve is effective and safe for the treatment of moderate to severe cubital tunnel syndrome, and initial severity, advancing age, and electrophysiological parameters can affect treatment outcome.

[Characteristics and perioperative management of hemophilia patients with fractures]

OBJECTIVE

To investigate the characteristics and perioperative management of hemophilia patients with fracture.

METHODS

Retrospectively, we analyzed 8 patients with hemophilia combined with fracture, who were admittted to our department from 2005 to 2013. Six patients were with hemophilia A and two with hemophilia B; Based on the severity of hemophilia, 2 cases were light, 3 moderate and 3 severe; Based on the location of fracture, 4 cases were femoral neck fractures, 1 femoral intertrochanteric fracture, 1 bilateral distal femur fractures, 1 tibiofibula fracture, and 1 humerus intercondylar fracture. Blood coagulation factor replacement therapy was conducted preoperatively, intraoperatively and postoperatively, All the patients underwent closed or open reduction and internal fixation or joint replacement. Also, we analyzed the perioperative complications and observed whether the fracture healed.

RESULTS

The average age was 33.5 years (14 to 47 years); In 6 cases, fractures occurred at femur, accounting for 75% of all the fractures; Femoral neck fracture was treated by closed reduction and hollow screws fixation; Femoral intertrochanteric fracture, distal femur fracture, and tibiofibula fracture were treated by open reduction and internal fixation with plate; Humerus intercondylar fracture was treated by elbow joint replacement. Intraoperative bleeding was from 50 to 600 mL, an average of 262 mL; Perioperatively, the average use of FVIII/activated prothrombin complex concentrates (APCC) was 358 U/kg (125 to 554 U/kg). Postoperatively, poor wound healing was observed in 2 patients, and the condition improved after symptomatic treatment; In patients with internal fixation, all the fractures united, and the average healing time was 14 weeks. No complications such as fixation loosening or rupture occurred after internal fixation.

CONCLUSION

Hemophilia combined with fracture mainly occurred in the young, and the site of fracture was given priority to femur. With perfect preoperative preparation, on the basis of the replacement therapy, hemophilia combined with fractures was safe for surgical treatment, and postoperative fractures healing wasgood. But the risk of poor wound healing was high.

[Clinical characteristics and risk factors of newly developed vertebral fractures after vertebral augmentation]

OBJECTIVE

To identify the characteristics and risk factors of the refractures after percutaneous kyphoplasty (PKP) and percutaneous vertebroplasty (PVP).

METHODS

A retrospective analysis of 148 patients who had undergone PKP or PVP between March 2006 and October 2013 in Peking University People's Hospital was conducted. In the study, 29 patients with 42 refractured vertebra and 119 patients without refracture were included. All the patients were observed for a time of (34.4±26.8) months. Clinical, imaging and procedure related factors (gender, age, height, weight, body mass index, the level of the injured vertebra, the time interval between the procedure and the refracture, the level of the refractured vertebra, the bone cement volume injected, performed PKP or PVP,performed unilateral or bilateral, the percentage of anterior vertebral height restoration, the correction of the Cobb angle, cement diffusion, bone mineral density, presence or absence of diabetes mellitus, history of fractures of the whole body, anti-osteoporosis treatment, cement leakage) for each group were analyzed by Cox proportional hazards regression analysis.

RESULTS

Of all the patients,16 (55.17%, 16/29) had refractures in the adjacent vertebra, and 13 (44.83%, 13/29) had refractures in the nonadjacent vertebra. Refractures within 3 months accounted for 31.03% (9/29) of all the refractures, and within 1 year accounted for 55.17% (16/29). Both older age (P=0.027, HR=1.051, 95% CI=1.006-1.098) and a history of fractures of the whole body (P=0.012, HR=0.386, 95% CI=0.184-0.812) were statistically significant as the independent risk factors for predicting refractures. Others were not associated with refractures (P>0.05).

CONCLUSION

Older age and a history of fractures of the whole body are the independent risk factors of the refractures after PKP and PVP. The mechanism of the refractures after PKP and PVP is mainly the natural development of osteoporosis.

[Applying percutaneous placement of guide wire combined with true lateral view fluoroscopy proximal femoral nail anti-rotation fixation]

OBJECTIVE

To apply modified proximal femoral nail anti-rotation (PFNA) fixation techniques performed by percutaneous placement of guide wire combined with true lateral view and to make the procedures simpler.

METHODS

A retrospective study was used to analyze the clinical data of femoral intertrochanteric fractures cases, which were treated with conventional PFNA fixation or modified PFNA fixation performed by percutaneous placement guide wire combined with true lateral view in our hospital, from March, 2011 to May, 2014. In the study, 60 cases were followed for average 13 months. The operation time, the amount of bleeding, the fluoroscopy time, postoperative radiographic measurements (tip apex distance, TAD) and hip function scores were analyzed.

RESULTS

In modified PFNA group, the amount of bleeding, the operation time and the fluoroscopy time were (34.9±6.1) mL, (70.5±12.5) min, (63.6±9.7) s respectively. In conventional PFNA group,they were (47.8±6.7) mL, (80.6±17.1) min, (68.5±8.7) s respectively. There were significant differences in the above respects between the two groups (P were 0.006, 0.013, and 0.022 respectively). There were no significant differences in TAD, fracture healing time, postoperative hip scores between the two groups (P>0.05).

CONCLUSION

Fracture line is a natural entry point for some cases of femoral intertrochanteric fractures when we use proximal femoral nail anti-rotation to fix the fracture. Applying percutaneous insertion of the guide pin combined with true lateral view could reduce the operation time, amount of bleeding, and fluoroscopy time significantly, make the procedures simpler and acquire satisfactory results .

Sleeve bridging of the rhesus monkey ulnar nerve with muscular branches of the pronator teres: multiple amplification of axonal regeneration

Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previous studies have verified the limit and validity of multiple amplification of peripheral nerve regeneration using small gap sleeve bridging of small donor nerves to repair large receptor nerves in rodents. The present study sought to observe multiple amplification of myelinated nerve fiber regeneration in the primate peripheral nerve. Rhesus monkey models of distal ulnar nerve defects were established and repaired using muscular branches of the right forearm pronator teres. Proximal muscular branches of the pronator teres were sutured into the distal ulnar nerve using the small gap sleeve bridging method. At 6 months after suture, two-finger flexion and mild wrist flexion were restored in the ulnar-sided injured limbs of rhesus monkey. Neurophysiological examination showed that motor nerve conduction velocity reached 22.63 ± 6.34 m/s on the affected side of rhesus monkey. Osmium tetroxide staining demonstrated that the number of myelinated nerve fibers was 1,657 ± 652 in the branches of pronator teres of donor, and 2,661 ± 843 in the repaired ulnar nerve. The rate of multiple amplification of regenerating myelinated nerve fibers was 1.61. These data showed that when muscular branches of the pronator teres were used to repair ulnar nerve in primates, effective regeneration was observed in regenerating nerve fibers, and functions of the injured ulnar nerve were restored to a certain extent. Moreover, multiple amplification was subsequently detected in ulnar nerve axons.

Biological conduit small gap sleeve bridging method for peripheral nerve injury: regeneration law of nerve fibers in the conduit

The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair peripheral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good histocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration (2-8 weeks), the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objective and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.

Use of nerve elongator to repair short-distance peripheral nerve defects: a prospective randomized study

Repair techniques for short-distance peripheral nerve defects, including adjacent joint flexion to reduce the distance between the nerve stump defects, "nerve splint" suturing, and nerve sleeve connection, have some disadvantages. Therefore, we designed a repair technique involving intraoperative tension-free application of a nerve elongator and obtained good outcomes in the repair of short-distance peripheral nerve defects in a previous animal study. The present study compared the clinical outcomes between the use of this nerve elongator and performance of the conventional method in the repair of short-distance transection injuries in human elbows. The 3-, 6-, and 12-month postoperative follow-up results demonstrated that early neurological function recovery was better in the nerve elongation group than in the conventional group, but no significant difference in long-term neurological function recovery was detected between the two groups. In the nerve elongation group, the nerves were sutured without tension, and the duration of postoperative immobilization of the elbow was decreased. Elbow function rehabilitation was significantly better in the nerve elongation group than in the control group. Moreover, there were no security risks. The results of this study confirm that the use of this nerve elongator for repair of short-distance peripheral nerve defects is safe and effective.