Electrospun Polycaprolactone (PCL)-Amnion Nanofibrous Membrane Promotes Nerve Regeneration and Prevents Fibrosis in a Rat Sciatic Nerve Transection Model.

Functional recovery after peripheral nerve injury repair is typically unsatisfactory. An anastomotically poor microenvironment and scarring at the repair site are important factors impeding nerve regeneration. In this study, an electrospun poly-e-caprolactone (PCL)-amnion nanofibrous membrane comprising an amnion membrane and nonwoven electrospun PCL was used to wrap the sciatic nerve repair site in the rat model of a sciatic nerve transection. The effect of the PCL-amnion nanofibrous membrane on improving nerve regeneration and preventing scarring at the repair site was evaluated by expression of the inflammatory cytokine, sciatic functional index (SFI), electrophysiology, and histological analyses. Four weeks after repair, the degree of nerve adhesion, collagen deposition, and intraneural macrophage invasion of the PCL-amnion nanofibrous membrane group were significantly decreased compared with those of the Control group. Moreover, the PCL-amnion nanofibrous membrane decreased the expression of pro-inflammatory cytokines such as interleukin(IL)-6, Tumor Necrosis Factor(TNF)-a and the number of pro-inflammatory M1 macrophages, and increased the expression of anti-inflammatory cytokine such as IL-10, IL-13 and anti-inflammatory M2 macrophages. At 16 weeks, the PCL-amnion nanofibrous membrane improved functional recovery, including promoting nerve Schwann cell proliferation, axon regeneration, and reducing the time of muscle denervation. In summary, the PCL-amnion nanofibrous membrane effectively improved nerve regeneration and prevent fibrosis after nerve repair, which has good clinical application prospect for tissue repair.

Electrospun Polycaprolactone (PCL)-Amnion Nanofibrous Membrane Promotes Nerve Repair after Neurolysis.

Peripheral nerve adhesion after neurolysis leads to nerve dysfunction, limiting nerve regeneration and functional recovery. We previously developed an electrospun polycaprolactone (PCL)-amnion nanofibrous membrane for preventing adhesion formation. In this study, we investigated the effect of protective nerve wrapping and promoting nerve regeneration in a rat sciatic nerve compression model. A total of 96 SD rats after sciatic nerve chronic compression were randomly divided into three groups: the PCL-amniotic group, in which nerves were wrapped with a PCL-amniotic membrane for treatment; the chitosan group, in which nerves were wrapped with a clinically used chitosan hydrogel; the control group, which involved neurolysis alone without treatment. Twelve weeks postoperatively, the nerve regeneration was evaluated by general and ultrastructure observation, as well as the expressions of neuronal regeneration and inflammatory reaction biomarkers. The nerve functions were assessed with gastrocnemius muscle measurement, hot-plate test, and walking track analysis. Compared with the chitosan hydrogel, the PCL-amnion nanofibrous membrane significantly reduced peripheral nerve adhesion and promoted nerve regeneration. The morphological properties of axons in the nerve wrap group were preserved. Intraneural macrophage invasion, as assessed by the number of CD68-positive cells, was less severe in the PCL-amnion group than in the other groups. Additionally, the gastrocnemius muscle weight and muscle bundle area were significantly higher in the PCL-amnion group than those in the chitosan group. The abilities of sense and movement of the rats in the PCL-amnion group were significantly improved compared to the other groups. In summary, electrospun PCL-amnion nanofibrous membranes effectively prevented post-neurolysis peripheral nerves from developing adhesion, whereas promoted nerve repair and regeneration, which make PCL-amnion nanofibrous membranes a promising biomaterial for clinical application.

Correction: Electrospun polycaprolactone (PCL)-amnion nanofibrous membrane prevents adhesions and promotes nerve repair in a rat model of sciatic nerve compression.

[This corrects the article DOI: 10.1371/journal.pone.0244301.].

Electrospun polycaprolactone (PCL)-amnion nanofibrous membrane prevents adhesions and promotes nerve repair in a rat model of sciatic nerve compression.

Adhesion and scarring after neural surgery are detrimental to nerve regeneration and functional recovery. Amniotic membranes have been used in tissue repair due to their immunogenicity and richness in cytokines. In this study, an electrospun polycaprolactone (PCL)-amnion nanofibrous membrane was prepared for the treatment of sciatic nerve compression in a rat model. The effects of the PCL-amnion nanofibrous membrane on the prevention of adhesion formation and nerve regeneration were evaluated using electrophysiology and histological analyses. Compared with the medical chitosan hydrogel dressing, the PCL-amnion nanofibrous membrane significantly reduced peripheral nerve adhesion and promoted the rapid recovery of nerve conduction. Moreover, the immunohistochemical analysis identified more Schwann cells and less pro-inflammatory M1 macrophages in the PCL-amnion group. Western blot and RT-PCR results showed that the expression levels of type-Ⅰ and Ⅲ collagen in the PCL-treated rats were half of those in the control group after 12 weeks, while the expression level of nerve growth factor was approximately 3.5 times that found in the rats treated with medical chitosan hydrogel. In summary, electrospun PCL-amnion nanofibrous membranes can effectively reduce adhesion after neural surgery and promote nerve repair and regeneration. The long-term retention in vivo and sustained release of cytokines make PCL-amnion a promising biomaterial for clinical application.

Regulation of ERK1/2 and SMAD2/3 Pathways by Using Multi-Layered Electrospun PCL-Amnion Nanofibrous Membranes for the Prevention of Post-Surgical Tendon Adhesion.

BACKGROUND: Adhesion after tendon injury is a common complication in clinical practice. The lack of effective prevention mechanisms seriously affects the functional rehabilitation of patients. This research aimed to optimise the amniotic membrane and explain the mechanism of tendon-amniotic membrane by imitating the tendon sheath to construct a multilayer electrospun polycaprolactone (PCL) nanofibre membrane. MATERIALS AND METHODS: Fresh amnions were subjected to freezing and vacuum drying. The two surfaces of freeze-dried amnions were coated with PCL nanofibres by electrospinning, thereby forming a multilayer composite membrane and constructing a growth factor-sustained release system conforming to the tendon-healing cycle. The new materials were characterised, and the biological effects on tenocytes and fibroblasts were evaluated. The tendon injury model of New Zealand rabbits was constructed to observe the effects on tendon adhesion and healing. RESULTS: After freezing and vacuum drying, fresh amnions were found to effectively remove most of the cell components but retained the active components TGF-ß1, bFGF, VEGF, and PDGF, as well as the fibrous reticular structure of the basement membrane. After coating with PCL nanofibres, a composite membrane mimicking the structure of the tendon sheath was constructed, thereby strengthening the tensile strength of the amnion. By up-regulating the phosphorylation of ERK1/2 and SMAD2/3, the adhesion and proliferation of tenocytes and fibroblasts were promoted, and collagen synthesis was enhanced. In the rabbit tendon repair model, the composite membrane effectively isolated the exogenous adhesion tissue and promoted endogenous tendon healing. CONCLUSION: The composite membrane mimicking the structure of tendon sheath effectively isolated the exogenous adhesion tissue and achieved good tendon slip. By slowly releasing the growth factors TGF-ß1, bFGF, VEGF and PDGF, the ERK1/2 and SMAD2/3 pathways were regulated. Consequently, endogenous tendon healing was promoted. This strategy can alternatively address the clinical problem of tendon adhesion.

Metformin Enhances Functional Recovery of Peripheral Nerve in Rats with Sciatic Nerve Crush Injury.

BACKGROUND The aim of this study was to explore the effect of metformin by inducing autophagy for enhancing functional recovery of peripheral nerve in rats with sciatic nerve crush injury. MATERIAL AND METHODS Autophagy was determined by electron microscopy, immunofluorescence, and Western blot analysis. Motor function recovery was studied by the footprint intensity method. Axonal growth and regeneration were detected through Western blot while axonal remyelination was analysed through immunocytochemistry. Sensory and functional recovery were assessed by reflexive motor function analysis. RESULTS The present study deciphered the role of autophagy induction by metformin in motor functions and peripheral nerve regeneration following sciatic nerve crush injury in rats. The process was detected by measuring autophagosomes and the expression of microtubule-associated protein 1A/1B-light chain 3 upon metformin treatment of sciatic nerve crush-injured rats. Neurobehavioral recovery by metformin was tested by CatWalk gait analysis, and we quantified expression of myelin basic protein MBP and neurofilament NF200 at the damage sight by immunoblotting. In metformin-treated injured rats, autophagy was upregulated, by which the number of dead cells was decreased. Motor function was also recovered after metformin treatment, which was accompanied by upregulation of MBP and NF200 through autophagy induction. Surprisingly, the motor regenerative capability was reduced by treatment with 3-methyl adenine (an autophagy inhibitor) in nerve-injured rats. CONCLUSIONS Our study revealed that pharmacological induction of autophagy has an important and active role in the regeneration of nerve and motor function regain.

Repair of thumb defect by using the toenail flap: biomechanical analysis of donor foot-a retrospective cohort study.

BACKGROUND: The thumb accounts for 50% of the total hand function. This study reports the functional outcomes and complications of people with traumatic thumb amputations who underwent toe-to-thumb reconstruction. METHODS: From January 2013 to January 2018, 29 patients with second-degree thumb defect underwent thumb reconstruction with distal phalangeal braided toenail flap. The footscan foot pressure gait analysis system was used to measure the index changes of the same foot before and after 1, 3 and 6 months. The contact area, peak pressure, impulse value, contact time of each gait phase, centre of gravity coordinate and foot balance were analysed statistically. RESULTS: Twenty-nine cases of thumb reconstruction recovered well. After following up for 6-15 months, the appearance of the reconstructed thumb was close to normal, and the sensation was restored to S3+. The two-point discrimination was 6-8 mm, and the function of the thumb was good. The function of the donor foot was well restored, and no skin ulceration, pain and claudication were noted during walking. Compared with that before the operation, the biomechanical indices of the donor foot were basically restored to normal 6 months after the operation. Only the stress and impulse values of the third metatarsal head were significantly increased, forming a stress concentration area centred on the third metatarsal head. CONCLUSIONS: This study confirmed that the toenail flap with distal phalangeal bone restored the second-degree thumb defect without destroying the main functional structure of the sole. The biomechanical indices of the donor foot were basically restored to normal 6 months after the operation. Only the stress concentration area centred on the third metatarsal head, and the pain on the forefoot was induced after the operation. Discomfort, callus formation, metatarsal fasciitis, etc., can lead to fatigue fracture of the third metatarsal bone in severe cases, which requires further follow-up and observation. TRIAL REGISTRATION: Clinicaltrials.gov , NCT03879941; registered on 10 March 2019, retrospectively.

Outcomes of volar locking plate (VLP) fixation for treatment of die-punch fracture of the distal radius: A retrospective single-surgeon study.

Distal radius fracture involving the lunate facet is a tough issue for surgeons, but currently there is scarcity of data on these injuries. This study aims to evaluate results of volar locking plate (VLP) for treatment of die-punch fractures of the distal radius.Between January 2013 and June 2017, a total of 37 patients with die-punch fractures of the distal radius were admitted and underwent VLP fixation. Clinical and radiographic data on these patients were extracted from their electronic medical records. Preoperative radiographs, CT scanning and 3D reconstruction were used to definitely diagnose this injury. Radiographs taken at immediate postoperation and at last follow-up were analyzed. Data on radial subsidence, articular step-off status, volar tilt, radial inclination, wrist motion range, grip strength and related complications at the final follow-up were documented for analysis. The overall outcomes of the injured limb were evaluated, based on the Gartland and Werley scoring system.The mean radial subsidence was 0.8 mm (0-3.3 mm), and articular step-off finally occurred in 4 patients (10.8%). The mean volar tilt was 9.5° (6°-15°), radial inclination 21° (12°-27°). The mean wrist was 84.2% in flexion of the contralateral uninjured wrist, 87.0% in extension, 92.2% in pronation and 94.5% in supination, respectively. The mean grip strength was 86% (range 56%-108%) of the contralateral un-injured upper limb. Gartland and Werley score demonstrated the excellent and good rate of 83.8%, with excellent result in 21 patients, good in 10, fair in 4 and poor in 2. Incidence of overall complications was 27.0% (10/37), with one requiring surgical intervention.VLP demonstrated its efficacy and safety for treatment of die-punch fractures. Prospective comparative studies with larger sample are required to compare the outcomes among different fixation methods, with expectation of precise and individualized treatment for every patient.Type of study/level of evidence: Therapeutic III.

The comparison of limited-incision versus standard-incision in treatment of carpal tunnel syndrome: A meta-analysis of randomized controlled trials.

BACKGROUND: Carpal tunnel syndrome is a common compressive neuropathy of the median nerve. Compared with standard release, the efficacy, safety, and postoperative complications of limited carpal tunnel release remain controversial. The purpose of this study was to compare the effects of the 2 treatments. METHODS: The English-language literature was searched using MEDLINE, Web of Science, and Embase. Randomized controlled trials that compared standard and limited incision for carpal tunnel release were included in the meta-analysis. Strength, interval to return to activities, the rate of adverse events, effectiveness, and operative time were compared. RESULTS: Thirteen randomized controlled trials (RCTs) containing 1020 patients were included. Limited incision treated patients showed better early recovery of grip strength (mean difference [MD], 4.25 [0.86-7.65]; P = .01) and pinch strength (MD, 1.37 [0.24-2.51]; P = .02) but no advantage after more than 6 months. Patients treated with limited incision showed an earlier return to activities (MD,-8.80 [-9.21 to -8.39]; P < .01) and reduced operative time (standardized mean difference [SMD], -1.68 [-3.24 to-0.12]; P = .04). The rate of adverse event was significantly higher in standard group compared with that in limited group (risk ratio [RR] 0.61, 95% CI 0.38-0.96, P = .03). CONCLUSIONS: Limited incision release allows us to return to activities early, reduces operative time, decreases rate of adverse events, and improves strength during the early postoperative period. Results at 6 months or longer are similar according to current data. However, the results of this meta-analysis should be interpreted with caution due to heterogeneity amongst the included studies.

Biological Amnion Prevents Flexor Tendon Adhesion in Zone II: A Controlled, Multicentre Clinical Trial.

INTRODUCTION: Tendon adhesion to surrounding tissues is the most common complication reported after tendon repair. To date, effective solutions to prevent tendon injury are still lacking. MATERIALS AND METHODS: A total of 89 patients with flexor tendon injury in zone II were recruited. The patients were divided into a control group, a poly-DL-lactic acid (PDLLA) group, and an amnion group according to the different tendon treatments applied. The control group was not subjected to other treatments. PDLLA and bioamniotic membranes were, respectively, used to wrap broken ends in the PDLLA and amnion membrane groups. The patients were followed at 1, 2, 3, 6, and 12 months after surgery and the ranges of active flexion and extension lag in the proximal and distal interphalangeal joints were evaluated. RESULTS: The means of total active ranges of motion of the interphalangeal joints (excluding rupture cases) in the PDLLA and amnion groups did not significantly differ between each other but significantly differed from that of the control group. Statistical analysis showed a significant difference in the clinical grades of the outcomes among the control, PDLLA, and amnion groups. The incidence of complications in the control and PDLLA groups was found to be significantly higher than that in the amniotic membrane group; no significant difference was observed between the control and PDLLA groups. CONCLUSION: In this study, freeze-dried amniotic membrane transplantation was applied to promote healing of the flexor tendon in zone II and prevent adhesion. This technique presents a new method to solve the issue of tendon adhesion after repair. CLINICAL TRIAL REGISTRATION: The trial was registered by identifier ChiCTR1900021769.

Platelet-rich plasma injection for the treatment of chronic Achilles tendinopathy: A meta-analysis.

BACKGROUND: Platelet-rich plasma (PRP) is used as an alternative therapy to reduce pain and improve functional restoration in patients with Achilles tendinopathy (AT). We evaluated the current evidence for the efficacy of PRP as a treatment for chronic AT. METHODS: The PubMed, Embase, Web of Science, and The Cochrane Library databases were searched for articles on randomized controlled trials (RCTs) that compared the efficacy of PRP with that of with placebo injections plus eccentric training as treatment for AT. The articles were uploaded over the establishment of the databases to May 01, 2018. The Cochrane risk of bias (ROB) tool was used to assess methodological quality. Outcome measurements included the Victorian Institute of Sports Assessment-Achilles (VISA-A), visual analog scale (VAS) and Achilles tendon thickness. Statistical analysis was performed with RevMan 5.3.5 software. RESULTS: Five RCTs (n = 189) were included in this meta-analysis. Significant differences in the VISA-A were not observed between the PRP and placebo groups after 12 weeks [standardized mean difference (SMD) = 0.2, 95% confidence interval (95% CI): 0.36 to 0.76, I = 71%], 24 weeks (SMD = 0.77, 95% CI: -0.10-1.65, I = 85%) and 1 year (SMD = 0.83, 95% CI: -0.76-2.42, I = 72%) of treatment. However, PRP exhibited better efficacy than the placebo treatment after 6 weeks (SMD = 0.46, 95% CI: 0.15-0.77, I = 34%). Two studies included VAS scores and tendon thickness. VAS scores after 6 weeks (SMD = 1.35, 95% CI: -0.1.04-3.74, I = 93%) and 24 weeks (SMD = 1.48, 95% CI: -0.1.59-4.55, I = 95%) were not significantly different. However, VAS scores at the 12th week (SMD = 1.10, 95% CI: 0.53-1.68, I = 83%) and tendon thickness (SMD = 1.51, 95% CI: 0.39-2.63, I = 53%) were significantly different. CONCLUSION: PRP injection around the Achilles tendon is an option for the treatment of chronic AT. Limited evidence supports the conclusion that PRP is not superior to placebo treatment. These results still require verification by a large number of well designed, heterogeneous RCT studies.

Experimental study of tendon sheath repair via decellularized amnion to prevent tendon adhesion.

The adhesion of tendon and surrounding tissue is the most common complication after repairing an injured tendon. The injured flexor tendons in zone II are frequently accompanied by tendon sheath defects, which lead to poor recovery. A variety of biological and non-biological materials have been recently used for repair or as substitute for tendon sheaths to prevent tendon adhesion. However, non-biological materials, such as polyethylene films, have been used to prevent tendon adhesions by mechanical isolation. The possibility of tendon necrosis and permanent foreign body remains due to the lack of permeability and the obstruction of nutrient infiltration. The natural macromolecule amniotic membrane derived from organisms is a semi-permeable membrane with the following characteristics: smooth; without vascular, nerve, and lymphatic; and rich in matrix, cytokines, enzymes, and other active ingredients. The unique structure of this membrane makes it an ideal biomaterial. In the experiment in Henry chicken, the model of tendon sheath defect and the flexor digitorum tendon in zone II was established and randomly divided into control group, medical membrane group, and decellularized amniotic membrane group. Samples were obtained at the 2nd, 4th, 8th, and 12th week after operation. General, histological, and biomechanical tests were performed to investigate the preventive effect of repaired tendon sheath by decallularized amniotic membrane. Experimental results showed the following: the amniotic membrane group and the medical membrane group had mild inflammatory reaction and tissue edema, and nearly no adhesion was observed in the surrounding tissue; the fibroblast-like cells were distributed in layers under the light microscope; the amniotic membrane group was denser than the medical membrane group cells, and numerous fibroblasts were disorganized in the control group. Biomechanical measurements showed that the sliding distance of tendon, the total flexion angle of the toes, and the tendon maximum tensile breaking strength at the early postoperative were significantly better than in the control group. Through this experiment, the amniotic membrane, as a natural biological substitute material in the construction of tendon sheath, can effectively inhibit exogenous healing and promote endogenous healing to prevent tendon adhesion.

Prevalence of and risk factors for Modic change in patients with symptomatic cervical spondylosis: an observational study.

BACKGROUND: The aim of this study was to assess the prevalence of cervical Modic change (MC) in patients with cervical spondylosis and to develop a better understanding of the possible risk factors for the prevalence of MC. METHODS: Between January 2014 and April 2017, patients with cervical spondylosis were included in our study. All patients underwent magnetic resonance imaging (MRI) to evaluate the presence of MC. The MC was classified into three types according to the Modic classification. Potential risk factors were collected from demographic data, lifestyle variables, laboratory tests, and radiographic images. Both univariate and multivariate analysis were used to detect factors associated with MC. We further compared several variables related to fat metabolism between patients with Type 1 and Type 2 MC. RESULTS: The prevalence of MC in patients with cervical spondylosis was 9.24%. The MC was most frequent at C5-6, followed by C6-7, C4-5, and C3-4. The proportion of Type 1 MC in patients with neck pain was significantly higher than that in patients without neck pain (46.2% vs 13.6%, P=0.027). However, none of the variables associated with fat metabolism showed a significant difference between Type 1 and Type 2 MC. Multivariate logistic analysis showed that age ≥55 years (odds ratio [OR], 1.91; 95% confidence interval [CI], 1.22-2.98) and body mass index (BMI) ≥25 kg/m2 (OR, 2.41; 95% CI, 1.62-3.59) were two significant independent factors that are associated with cervical MC in patients with cervical spondylosis (P<0.05). CONCLUSION: It appears that advanced age and high BMI were two factors that may be responsible for cervical MC. Type 1 MC is associated with the prevalence of neck pain. However, we cannot confirm that Type 2 MC is correlated with fat metabolism.

Carpal tunnel release with a new mini-incision approach versus a conventional approach, a retrospective cohort study.

PURPOSE: We have make use of a new method to perform carpal tunnel release (CTR) through a 1.5-2.0 cm long incision The aim of this study is to introduce this method and to compare the effectiveness and safety of this approach to the conventional one. METHODS: We included consecutive patients diagnosed with primary carpal tunnel syndrome (CTS) who had CTR from January 2015 to September 2016. A total of 85 patients were included in our study. Among them, 42 patients with mini-incision approach were enrolled in group A, and the other 43 patients with conventional approach were enrolled in group B. Objective tests and subjective evaluations were performed to compare the outcomes of mini-incision approach with the conventional approach. Postoperative complications after the two approaches were also compared. RESULTS: At the 12-months follow-up, all patients in both groups got recovery. We found no significant differences between the two groups in postoperative pinch strength, grip strength, 2-point discrimination (2-PD), visual analogue scale (VAS) score, Levine score and the Disabilities of the Arm, Shoulder and Hand (DASH) score (P > 0.05). However, at the one-month follow-up, the percentage of patients with wound pain in group A was significantly lower than that in group B (0.05% vs. 0.23%, P = 0.03). At the 12 months follow-up, the number of patients with persistent wound pain and pillar pain in group B were 2 (4.7%) and 3 (7.0%) respectively, while no patients showed wound pain and pillar pain in group A. CONCLUSION: Patients with mini-incision approach have satisfactory surgical outcomes, low postoperative complications, and good appearance.

Predictors of surgical outcomes after in situ ulnar nerve decompression for cubital tunnel syndrome.

BACKGROUND: In the treatment of cubital tunnel syndrome (CuTS), in situ ulnar nerve decompression is commonly used. This study aims to investigate predictive factors for poor recovery and ulnar nerve instability following this procedure. METHODS: We enrolled 235 patients who underwent in situ ulnar nerve decompression for the treatment of CuTS from January 2010 to December 2014. All patients underwent >2 years' follow-up. The primary outcome was postoperative recovery, which was assessed by Messina's criteria, and the secondary outcome was postoperative ulnar nerve instability. Potential risk factors were collected from demographic data and electrodiagnostic test, which included age, gender, body mass index, history of tobacco or alcohol use, history of major medical comorbidities, disease duration, preoperative severity, motor conduction velocity, and sensory conduction velocity. RESULTS: A total of 208 patients (88.5%) had satisfactory outcomes, while the other 27 patients (11.5%) had not. There were 25 patients (10.6%) showing postoperative ulnar nerve instability during follow-up. The multivariate analysis showed that only severe preoperative symptom (odds ratio [OR], 3.06; 95% confidence interval [CI], 2.16-4.32) was associated with unsatisfactory postoperative outcomes in patients with CuTS (P<0.001). In the model investigating independent factors associated with postoperative ulnar nerve instability, we found that young age (OR, 2.41; 95% CI, 1.63-3.58) was associated with the incidence of postoperative ulnar nerve instability (P<0.001). CONCLUSION: We found that severe preoperative symptom was associated with unsatisfactory postoperative outcomes, and young age was a risk factor for the incidence of postoperative ulnar nerve instability. Patients with these risk factors should be informed of the possibility of worse surgical outcomes.

Survivorship Analysis of Clinical Adjacent-Segment Pathology After Single-Level Cervical Fusion.

BACKGROUND Clinical adjacent-segment pathology (CASP) is an important problem after anterior cervical surgery. The purpose of this study was to predict prevalence of CASP and determine the possible risk factors for CASP after single-level anterior cervical discectomy and fusion surgery. MATERIAL AND METHODS We retrospectively reviewed a series of patients who underwent single-level cervical discectomy and fusion surgery (ACDF). Both basic and radiographic data of patients were collected. Life-table method and Kaplan-Meier analysis were used to calculate prevalence of CASP and disease-free survival rate. Cox analysis was performed to determine the predictive factors for it. RESULTS A total of 256 patients were included in this study. The mean length of follow-up was 70.64 months. Among them, 31 patients were diagnosed as having CASP during follow-up. Nineteen of them were at the cephalad adjacent segment, and the other 12 were at the caudal segment. After ACDF procedures, 10.01% of patients developed new symptoms of CASP within 5 years, and the incidence increased to 23.89% after 10 years. The incidence rate of CASP was an average of 2.46% per year. Multivariate Cox regression analysis showed that congenital stenosis (hazard ratio [HR], 3.250; 95% confidence interval [CI], 1.538-6.867) and degeneration of adjacent segment (HR, 2.681; 95% CI, 1.259-5.709) were correlated with the incidence of CASP. CONCLUSIONS Patients with congenital stenosis and pre-existing degenerative changes of adjacent segments had a higher risk of developing CASP after single-level anterior cervical discectomy and fusion.

Identification of key genes associated with the effect of osmotic stimuli on intervertebral discs using microarray analysis.

The present study aimed to explore the effect of osmotic stimuli on intervertebral discs (IVDs) using microarray analysis. Gene expression dataset GSE1648 was downloaded from the Gene Expression Omnibus database. There were 11 IVD cell samples in this dataset, which included 4 hyperosmotic stimuli samples, 3 hypoosmotic stimuli samples and 4 isosmotic stimuli samples. The differentially expressed genes (DEGs) in hyperosmotic or hypoosmotic IVD cells (designated DEGs-hyper or DEGs-hypo) were identified, compared with isosmotic cells, using the limma package of R software. The Database for Annotation, Visualization and Integrated Discovery was used to perform a Gene Ontology (GO) term enrichment analysis for the DEG sets. Protein-protein interaction (PPI) network and microRNA (miRNA) gene-regulatory network data for the DEG sets were obtained using the Human Protein Reference Database (HPRD) and the TargetScan database, respectively, and these networks were constructed and visualized using Cytoscape software. There was a total of 43 DEGs in DEGs-hyper and 9 in DEGs-hypo. Analysis of DEGs-hyper revealed that 41 GO terms were significantly enriched. In total, 376 pairs and 382 nodes were involved in the PPI network, and 1,314 miRNA-gene pairs and 422 nodes were contained in the miRNA-gene-regulated network. The results of the present study indicated that potential target genes (including NCOA3, SOS1, XPO1, ZBTB18, EFNB2 and SOBP) may be involved in the effect of osmotic stimuli on IVD, and the biological processes of apoptosis and cell death may be associated with the effect of high osmolality on IVD disease. The potential targets identified in the present study are more reliable than those identified by previous studies.

Comparative study of type B distal radius fractures with and without lunate facet involvement treated by volar locking plate, an observational study.

PURPOSE: This study aimed to evaluate the results of volar locking plate for treatment of type B distal radius fractures involving the lunate facet and compare them with those without involvement in lunate facet. METHOD: s: This was a retrospective study. A total of 93 patients with type B distal radius were treated by single volar locking plate between January 2014 and December 2015. Preoperative digital radiographs were used to initially diagnose and further classify this injury according to AO/OTA classification system. CT scanning or reconstruction was used to diagnose the complex or suspicious cases. Patients with lunate facet involvement were defined as group 1 (n = 21) and the remaining without luante facet involvement as group 2 (n = 72). Postoperative immediate radiographs and radiographs at last visit were analyzed. We evaluated clinical outcomes at minimum of 12 months and performed statistical analysis using the SPSS 19.0 software package. RESULTS: Bony union was reached in all participants, at the median time of 8 weeks. At the final follow-up, there were no significant difference observed in term of volar tilt and radial inclination between both groups (P, 0.172; 0.514). Articular step-off in group 1 was significantly greater than those of group 2 (P, 0.016). Significant articular step-off (>2 mm) occurred in 4 patients (19.0%) in group 1 and 3 (4.2%) in group 2 (P = 0.044). At 3-months postoperatively, group 1 showed worse results than group 2 for most variables (P < 0.05). At 6-months postoperatively, the differences for wrist flexion, supination, ulnar deviation and VAS in motion remained significant between both groups (P < 0.05). At the last follow-up, no significant differences were observed for any variable (P > 0.05). Five minor complications occurred in group 1 and 11 in group 2, and the difference was not significant (P = 0.346). CONCLUSIONS: Patients with distal radius fractures involving lunate facet would obtain more slow recovery, especially for wrist flexion, supination, ulnar deviation and VAS in motion. In addition, patients with lunate facet fractures would be at higher risk of loss of reduction and final articular step-off.

Diagnosis and treatment of hidden lesions in "mild" cervical spondylotic myelopathy patients with apparent symptoms.

Patients with apparent symptoms of cervical spondylotic myelopathy (CSM) may only show a mild compressive lesion in ordinary magnetic resonance imaging (MRI). The aim of this study was to investigate the characteristics of CSM patients with "hidden" lesions on kinetic MRI and to determine an effective treatment.Thirty-one patients with obvious spinal cord compression only on kinetic MRI were included in our study. A variety of parameters were calculated from MRI of the cervical spine at different postures. The anterior cervical decompression and fusion (ACDF) procedure were used for treatment of CSM. To evaluate the effect of surgery, a further 31 age- and gender-matched ordinary CSM patients that received ACDF procedures were enrolled as the control group.The diameter of the cervical cord at the narrowest level in extension was significantly lower than that in the neutral posture (P < .01). The percentage of spinal cord compression was 34.6%. The diameter of the cervical canal at the narrowest level in the extension posture was significantly lower than that in the neutral posture (P < .01). The percentage of cervical canal stenosis was 43.6%. The anteroposterior diameter of the cervical canal in the case group was significantly lower than that in the control group (P < .01). However, the recovery rate of the Japanese Orthopaedic Association score at final follow-up was comparable between the case group and the control group (P = .53).Kinetic MRI is useful for the diagnosis of CSM with hidden lesions. ACDF is an effective procedure for treatment of CSM.

The prevalence of heterotopic ossification among patients after cervical artificial disc replacement: A systematic review and meta-analysis.

BACKGROUND: Prevalence estimates of heterotopic ossification (HO) following cervical artificial disc replacement (ADR) varied widely in previous studies. We conducted a systematic review and meta-analysis to summarize its point prevalence. METHODS: Electronic searches of PubMed, Web of Science, Embase, and Cochrane Library databases were conducted to identify studies that reported prevalence of HO. Definitions of HO and severe HO were based on McAfee grading system. Random-effects model was used to estimate the pooled prevalence. We conducted subgroup analyses according to the different length of follow-up time, and performed univariate metaregression analyses to explore the effects of potential variables on the overall prevalence. RESULTS: A total of 38 studies were included in this study. The pooled data showed that the prevalence of HO after cervical ADR within the 1 to 2 years, 2 to 5 years, and 5 to10 years of follow-up was 38.0% (95% confidence interval [CI], 30.2%-46.5%), 52.6% (95% CI, 43.1%-61.9%), and 53.6% (95% CI, 40.0%-66.7%), respectively, while the prevalence of severe HO was 10.9% (95% CI, 9.0%-13.2%), 22.2% (95% CI, 15.5%-30.7%), and 47.5% (95% CI, 30.0%-65.8%), respectively. Follow-up time was positively associated with the prevalence of severe HO (P < .01), and the 1-month growth of mean follow-up went with 0.63% increase of severe HO. CONCLUSION: This meta-analysis reported data on the prevalence of HO and severe HO after cervical ADR, and provided information on its process of development. These should be useful to enable surgeons and patients to gain a better understanding of HO after cervical ADR.