Reversible pH-Gated MXene Membranes with Ultrahigh Mono-/Divalent-Ion Selectivity.

Artificial ion channel membranes hold high promise in water treatment, nanofluidics, and energy conversion, but it remains a great challenge to construct such smart membranes with both reversible ion-gating capability and desirable ion selectivity. Herein, we constructed a smart MXene-based membrane via p-phenylenediamine functionalization (MLM-PPD) with highly stable and aligned two-dimensional subnanochannels, which exhibits reversible ion-gating capability and ultrahigh metal ion selectivity similar to biological ion channels. The pH-sensitive groups within the MLM-PPD channel confers excellent reversible Mg2+-gating capability with a pH-switching ratio of up to 100. The mono/divalent metal-ion selectivity up to 1243.8 and 400.9 for K+/Mg2+ and Li+/Mg2+, respectively, outperforms other reported membranes. Theoretical calculations combined with experimental results reveal that the steric hindrance and stronger PPD-ion interactions substantially enhance the energy barrier for divalent metal ions passing through the MLM-PPD, and thus leading to ultrahigh mono/divalent metal-ion selectivity. This work provides a new strategy for developing artificial-ion channel membranes with both reversible ion-gating functionality and high-ion selectivity for various applications.

Two-dimensional MXene membranes with biomimetic sub-nanochannels for enhanced cation sieving.

Membranes with high ion permeability and selectivity are of considerable interest for sustainable water treatment, resource extraction and energy storage. Herein, inspired by K+ channel of streptomyces A (KcsA K+), we have constructed cation sieving membranes using MXene nanosheets and Ethylenediaminetetraacetic acid (EDTA) molecules as building blocks. Numerous negatively charged oxygen atoms of EDTA molecules and 6.0 Å two-dimensional (2D) sub-nanochannel of MXene nanosheets enable biomimetic channel size, chemical groups and tunable charge density for the resulting membranes. The membranes show the capability to recognize monovalent/divalent cations, achieving excellent K+/Mg2+ selectivity of 121.2 using mixed salt solution as the feed, which outperforms other reported membranes under similar testing conditions and transcends the current upper limit. Characterization and simulations indicate that the cation recognition effect of EDTA and partial dehydration effects play critical roles in cations selective sieving and increasing the local charge density within the sub-nanochannel significantly improves cation selectivity. Our findings provide a theoretical basis for ions transport in sub-nanochannels and an alternative strategy for design ions separation membranes.

Nanoconfinement enabled non-covalently decorated MXene membranes for ion-sieving.

Covalent modification is commonly used to tune the channel size and functionality of 2D membranes. However, common synthesis strategies used to produce such modifications are known to disrupt the structure of the membranes. Herein, we report less intrusive yet equally effective non-covalent modifications on Ti3C2Tx MXene membranes by a solvent treatment, where the channels are robustly decorated by protic solvents via hydrogen bond network. The densely functionalized (-O, -F, -OH) Ti3C2Tx channel allows multiple hydrogen bond establishment and its sub-1-nm size induces a nanoconfinement effect to greatly strengthen these interactions by maintaining solvent-MXene distance and solvent orientation. In sub-1-nm ion sieving and separation, as-decorated membranes exhibit stable ion rejection, and proton-cation (H+/Mn+) selectivity that is up to 50 times and 30 times, respectively, higher than that of pristine membranes. It demonstrates the feasibility of non-covalent methods as a broad modification alternative for nanochannels integrated in energy-, resource- and environment-related applications.

[Treatment of acute unstable proximal clavicular fracture with hook plate of sternoclavicular joint].

OBJECTIVE: To investigate clinical effect of sternoclavicular hook plate in treating acute proximal clavicle fracture. METHODS: The clinical of 12 patients with acute unstable proximal clavicle fracture from June 2016 to June 2019 were retrospectively analyzed. There were 8 males and 4 females, aged from 46 to 63 years old. Ten patients caused by car accident and 2 patients caused by high falling. All patients had multiple injuries;the time from injury to surgery ranged from 2 to 14 d. All patients were treated with domestic sternoclavicular joint hook plate. The operative time ranged from 40 to 115 min. The intraoperative bleeding volume ranged from 30 to 110 ml, follow-up time ranged from 10 to 36 months, the fracture healing time ranged from 8 to 18 weeks. At the latest follow-up, the efficacy was evaluated by using shoulder joint function score (Rockwood score). RESULTS: All 12 patients were followed up, with no obvious pain at the latest follow-up. The rockwood scores of the affected shoulder ranged from 13 to 14, and the healthy shoulder ranged from 14 to 15. CONCLUSION: The sternocleidoclavicular joint plate is fixed with preformed plate. The cantilever is designed to retain the motion of the sternoclavicular joint. It's safe and simple, avoid, the injury of important organs during operation, and has a good prognosis. It is an ideal fixation method for the treatment of proximal clavicle fracture.

Oriented UiO-67 Metal-Organic Framework Membrane with Fast and Selective Lithium-Ion Transport.

Metal-organic frameworks (MOFs) membranes with high pore density and tunable pore size down to the subnanoscale exhibit great potential in ion separation when appropriately designed and prepared. By a washing-assisted secondary growing method, a well intergrown UiO-67 membrane with preferential growth along the [022] direction was synthesized on a polyvinylpyrrolidone (PVP)-modified AAO substrate. Because of the oriented growth of UiO-67 nanocrystals, highly interconnected ion-transporting channels are created throughout the UiO-67/AAO membrane capable of achieving an ultrahigh Li+ permeance of 27.01 mol m-2 h-1 as well as very decent Li+ /Mg2+ selectivity of up to 159.4. Molecular dynamics simulations reveal that the high selectivity is associated with the large disparity of the transport energy barrier between Li+ and Mg2+ , which is caused by different extents of ion dehydration in unique bimodal and oriented membrane channels.

[Wiltse approach combined with contralateral transforaminal lumbar interbody fusion and conventional surgery for lumbar disc herniation:a case-control study].

OBJECTIVE: To compare the clinical effecty of Wiltse approach combined with contralateral transforaminal lumbar interbody fusion (TLIF) and traditional TLIF in the treatment of lumbar disc herniation and its affect on injury of multifidus muscle. METHODS: From June 2014 to September 2017, 90 patients with lumbar disc herniation combined with lumbar spine instability were divided into two groups (Wiltse approach group and traditional group) depend on the procedure of operation. Wiltse approach group was treated with Wiltse approach screw placement in one side combined with contralateral TLIF. There were 50 patients in Wiltse approach group, including 36 males and 14 females, aged 45 to 72 yearswith an average of (60.4± 3.1) years. The traditional group was treated with traditional TLIF operation. There were 40 patients in the traditional group, including 25 males and 15 females, aged 45 to 74 years with an average of (62.1±3.4) years. The operative time, intraoperative blood loss, accuracy of screw implantation, postoperative drainage volume and drainage tube removal time were recorded in two groups. Visual analogue scale (VAS) and Oswestry Disability Index (ODI)were observed before and 12 months after operation. All patients underwent CT examination preoperative and 12 months postoperative, and the CT values of bilateral multifidus muscle were measured. RESULTS: All the patients were followed up, 40 patients in traditional group were 12 to 18 months with an average of (15.3±4.3) months; and 50 patients in Wiltse approach group were 13 to 24 months with an average of (16.5± 4.1) months. There were no statistically significant differences in operative time and intraoperative blood loss between two groups (P>0.05). The accuracy of screw implantation in Wiltse approach group was higher than traditional group (P<0.05).There was no significant difference in preoperative VAS score and ODI between two groups, and 12 months after operation, VAS score and ODI in Wiltse approach group was significantly lower than traditional group (P <0.05). The postoperative drainage and drainage tube placement time in Wiltse approach group were lower than the traditional group(P<0.05). There was no statistically significant difference in CT value of multifidus muscle before operation between two groups (P>0.05), while there was statistically significant difference after operation (P<0.05). Postoperative CT values of multifidus muscles on decompression and non-decompression side were obviously reduced in traditional group (P<0.05). The CT value of the multifidus muscle on the decompression side of the Wiltse approach group was significantly lower than that before operation(P<0.05), and there was no significant difference before and after the operation on the non-decompression side (P>0.05). CONCLUSION: Compared with traditional surgical procedures, the Wiltse approach nail placement combined with contralateral TLIF has the advantage of accurate nail placement, reducing multifidus muscle damage, and reducing the incidence of postoperative intractable low back pain.

Effectiveness of 2 Types of Drill Templates for Cervical Anterior Transpedicular Screw Placements: A Comparative Study.

OBJECTIVE: To evaluate effectiveness of regular and modified drill templates used to guide cervical anterior transpedicular screw (ATPS) placement. METHODS: This study included 15 adult cadaveric specimens. Computed tomography images were imported into Mimics software. Three-dimensional modeling of all cervical vertebrae was done, and the ideal trajectories were designed for ATPSs. Models of regular and modified templates were designed for every level on the left or right side randomly. After three-dimensional printing, 2 types of templates were used to guide the insertion. Postoperative computed tomography scans were used to measure deviations between real and ideal trajectories in the direction and positioning of entry points. The deviations in the 2 groups were compared using paired t test. RESULTS: There were 120 templates and ATPSs fabricated and placed. Postoperative images showed that 7 screws perforated pedicles in the regular group, with an accuracy rate of 88.3%. Deviations between real and ideal trajectories in cranially inclined angles and extroversive angles were 1.13° ± 0.61° and 0.97° ± 0.60°, respectively, and deviations of entry point position in the x-axis and y-axis were 0.72 ± 0.38 mm and 0.95 ± 0.47 mm, respectively. In the modified group, there were 2 malposition screws with accuracy rate of 96.7%. Deviations in cranially inclined angles were 0.66° ± 0.53° and 0.66° ± 0.55° in extroversive angles, respectively, and deviations in entry point positions in the x-axis and y-axis were 0.45 ± 0.37 mm and 0.51 ± 0.34 mm, respectively. The differences in deviations between groups were statistically significant. CONCLUSIONS: Compared with regular drill templates, modified drill templates can provide higher accuracy and stronger trajectory control in ATPS insertions.

Modified kyphoplasty with controllable balloon dilatation for treatment of thoracolumbar osteoporotic vertebral compression fractures.

PURPOSE: To investigate the surgical effects of modified kyphoplasty with controllable balloon dilatation for treatment of thoracolumbar osteoporotic vertebral compression fractures (OVCF). METHODS: From April 2013 to October 2017, a total of 53 patients with thoracolumbar OVCF were treated with controllable balloon percutaneous kyphoplasty (C-PKP). Peri-operative parameters including days from injury to operation, operation time, injected cement volume, cement leakage and complications were collected. Visual analogue scale (VAS) and Cobb angle before and after operation were applied to evaluate surgical effects. Moreover, a total of 53 cases treated with traditional balloon of percutaneous kyphoplasty were retrospectively analyzed and compared with C-PKP in above parameters. RESULTS: C-PKP achieved significant fewer events of cement leakage (type C) than that of traditional PKP (5/53 vs 13/53, p < 0.01). The patients were followed up for 10.8 ± 4.2 months; VAS and Cobb angle of the injured vertebra in both two groups at three days and final follow-up were significantly improved compared with that before surgery (p < 0.05), while there were no significant differences between the two groups regarding the VAS and Cobb angle at corresponding time points (p > 0.05). CONCLUSIONS: C-PKP technology is a safe and efficient way for the treatment of thoracolumbar OVCF, and it can reduce cement leakage.

[Effect of posterior osteotomy on the sagittal parameters of the spinopelvis in patients with lumbar degenerative kyphosis].

OBJECTIVE: To investigate the influence of posterior osteotomy on spinopelvic parameters in lumbar degenerative kyphosis (LDK) patients. METHODS: The clinical data of 21 patients with lumbar degenerative kyphosis who underwent osteotomy from January 2012 to December 2015 were retrospectively analyzed. There were 5 males and 16 females, aged from 55 to 76 years with an average of (66.24±5.13) years. All patients had taken preoperative and postoperative full length spinal X-ray, analyzing the spinopelvic parameters as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). RESULTS: All operations were successful, the average operative time was 190 min (160 to 220 min) and intraoperative blood loss was 1 000 ml (800 to 1900 ml). Parameters of the patients between preoperative and period 1-year follow-up were as follows : preoperative TK increased from (31.67±21.13) ° to (34.67±11.60) °, LL corrected from (4.76±3.17) ° to (37.41±6.28) °, PT reduced from (33.94±5.01) ° to (20.12±5.36) °, and SS improved from (18.47±2.60) ° to (31.71±4.30) °, SVA restored from (13.24±3.60) cm to (2.82±1.33) cm. There were significant differences of spinopelvic parameters between preoperation and postoperation (P<0.05). CONCLUSION: Posterior osteotomy can effectively reconstruct the sagittal balance of spinopelvis in patients with lumbar degenerative kyphosis. The recovery of lumbar lordosis and sacral slope is closely related to the reconstruction of sagittal balance.

Expression and function of Toll­like receptors in peripheral blood mononuclear cells in patients with ankylosing spondylitis.

Ankylosing spondylitis (AS) is a common chronic inflammatory autoimmune disease. Toll­like receptors (TLRs) are involved in non­specific immunity. In the present study, the roles of TLRs in AS were investigated. The levels of inflammatory cytokines were detected by ELISA and reverse transcription­quantitative polymerase chain reaction (RT­qPCR). The expression levels of TLRs and nuclear factor­κB (NF­κB) signaling­associated factors were determined via RT­qPCR and western blot analyses. It was observed that the levels of interleukin (IL)­6, tumor necrosis factor­α (TNF­α), C­reactive protein, TLR4 and TLR5 were increased in patients with AS, whereas those of IL­10 and TLR3 were decreased. Pomalidomide, a TNF­α release inhibitor, reduced the expression of IL­6, TNF­α, TLR4, TLR5 and phosphorylated­p65, and upregulated that of IL­10, TLR3 and p65 in peripheral blood mononuclear cells from patients with AS. Treatment of patients with infliximab, an anti­TNF­α monoclonal antibody, induced similar effects in vivo. In conclusion, it was revealed that inhibition of TNF­α suppressed inflammatory responses in patients with AS, increased the expression of TLR3 and decreased NF­κB signaling, and the expression of TLR4 and TLR5. The results indicated that TLRs and the NF­κB signaling pathway were involved in the regulation of inflammatory responses in AS. These findings provided insight into the mechanisms underlying the development of AS and potential novel therapeutic approaches.

[Digital modeling and analysis of the applicability of backward rotation method in lumbar kyphoplasty with unilateral puncture].

OBJECTIVE: The 3D model of lumbar spine was established by using Mimics software. To observe the applicability and needling parameters of lumbar vertebral kyphoplasty with unilateral puncture by backward rotation method using simulated puncture. METHODS: Twenty-four patients (12 males and 12 females) with osteoporotic thoracic fracture in the first time and no signs of lumbar misalignment and bone destruction were scanned by spiral CT on the lumbar spine. The original DICOM file was modeled in 3D with Mimics software, and the vertebral bodies were separated. After being imported into 3-matic software, the posterior wall of the vertebral body was restrained for standardized measurement. A sketch perpendicular to the mid-section of the pedicle and the posterior wall of the vertebral body was drawn. The simulated puncture was performed on the sketch. The angle and distance parameters of the range of motion of the puncture needle were recorded, and the puncture needle was recorded at the top. The crossing points of the anterior, middle and posterior zones of the tangential line of the vertebral body were located at the high extraversion angle, and the results were compared and analyzed. RESULTS: All the data in the left and right sides had no significantly differences(P>0.05). Data of different segments in different gender were significantly differences(P<0.05). The maximal extraversion angle in lumbar spine increased gradually from (33.41±1.31) degree to (56.53±4.71) degree in males, as same as in females from(28.58±2.55) to (53.86±2.68) degree. There was no crossing point in area A, 3.3% of males and 26.67% of females in area B, rest in area C. The distribution areas on gender showed statistically significance (P<0.05). CONCLUSIONS: Backward rotation method can theoretically meet the requirements of puncture point for vertebral compression fracture, especially for males and lower lumbar spine. The determination of the maximum inclination angle is of guiding significance to the backward rotation method.

[Case control study of unilateral and bilateral intervertebral space release in the treatment of lower lumbar spondylolisthesis].

OBJECTIVE: To analyze the clinical efficacy of unilateral and bilateral intervertebral space release in the treatment of lower lumbar spondylolisthesis. METHODS: The clinical data of 41 patients with lumbar spondylolisthesis treated by surgery from October 2012 and May 2016 were retrospcetive analyzed. The patients were divided into two groups, 18 cases were enrolled in unilateral intervertebral release group, there were 7 males and 11 females, aged from 47 to 75 years old with an average of (59.3±6.4) years; according to Meyerding classification, 9 cases of I degree, 7 cases of II degree, 2 cases of III degree. And 23 cases were bilateral release group, there were 11 males and 12 females, aged from 51 to 76 years old with an average of (58.2±5.7) years; according to Meyerding classification, 11 cases of I degree, 10 cases of II degree, 2 cases of III degree. The operation time, intraoperative blood loss, bone graft fusion rate of the patients were recorded in the patients. Pre- and post-operative back and leg pain were evaluated by visual analogue scale (VAS) between two groups. The slip rate, slip angle, posterior height of intervertebral space, height of intervertebral foramen, distance of anterior and posterior displacement of vertex of intervertebral foramen were measured on X-ray and CT. And the above radiographic data were analyzed by intra-group or inter-group. RESULTS: All the patients were followed up from 9 to 24 months with an average of 12 months. The entire 41 patient obtained bone fusion at 12 months after operation. There was no statistical significance in VAS at 12 months after operation, intraoperative blood loss and operation time between two groups(P>0.05). There were statistical significance in sliding angle, posterior height of intervertebral space, height of intervertebral foramen, distance of anterior and posterior displacement of vertex of intervertebral foramen of all patients before and after operation(P<0.05). There was no statistical significance in spondylolisthesis rate in unilateral release group between pre- and post-operative(P>0.05), but there was significant difference in bilateral release group. There was statistical significance in postoperative slip angle, posterior height of intervertebral space, distance of anterior and posterior displacement of vertex of intervertebral foramen between two groups(P=0.001, 0.045, 0.001). The height of intervertebral foramen increased and the slippage rate decreased in both groups after operation, but there was no significant difference between two groups(P=0.248). CONCLUSIONS: Unilateral and bilateral intervertebral space release for the treatment of lumbar spondylolisthesis can obviously reduce the rate of spondylolisthesis, restore foraminal height and achieve better clinical efficacy. Bilateral release group can better restore the slip angle, increase posterior height of intervertebral space, reduce the distance of anterior and posterior displacement of vertex of intervertebral foramen. Especially for grade II or above degree of slippage is more appropriate.

[Percutaneous transforaminal endoscopic discectomy via lateral position assisted with local anesthesia for lumbar disc herniation in elder with systemic diseases].

OBJECTIVE: To explore the clinical effect of percutaneous transforaminal endoscopic discectomy via lateral position assisted with local anesthesia for lumbar disc herniation in elder with systemic diseases. METHODS: The clinical data of 44 elder patients with lumbar disc herniation and systemic diseases treated from June 2013 to June 2017 were retrospectively analyzed. Including 26 males and 18 females, aged 70 to 86 years old with an average of(77.5±3.5) years, course of disease was 3 weeks to 6 months. Percutaneous transforaminal endoscopic discectomy via lateral position assisted with local anesthesia was performed in the patients. Postoperative straight leg-raising degree change and Nakai criteria were used to evaluate the operative effect. Visual analogue scale(VAS) and JOA scoring system were used to compare the symptom improvement between preoperative and postoperative. RESULTS: No serious complications occurred during and after the operation, and the coexisting medical diseases were not aggravated. All patients safely survived the perioperative period. All the 44 cases were followed up from 6 to 30 months with an average of 20 months. Postoperative straight leg raising angle was obviously improved. At final follow-up, according to Nakai standard, 41 cases got excellent results, 3 good. VAS scores were significantly decreased and JOA scores were significantly increased in final follow-up(P<0.01). CONCLUSIONS: Percutaneous transforaminal endoscopic discectomy via lateral position assisted with local anesthesia is a safe, effective, less invasive technique for the treatment of lumbar disc herniation in elder with systemic diseases. Multidisciplinary collaboration and perioperative well controlled disease are essential for early rehabilitation of such patients.

Surgical treatment for terrible triad injury of the elbow with anteromedial coronoid fracture through a combined surgical approach.

Objective To report the results of the surgical treatment of terrible triad injury with anteromedial coronoid fracture through a combined surgical approach. Methods This retrospective study evaluated data from patients who underwent surgery to repair terrible triad injuries and anteromedial coronoid fractures. Surgical treatment involved radial head repair or replacement, medial and lateral collateral ligament repair, and coronoid fracture fixation through combined approaches. Evaluations were performed using the Mayo Elbow Performance Score (MEPS) and anteroposterior and lateral radiographs of the elbow. Results Twenty-two patients (15 males, seven females; mean ± SD age, 47.5 ± 11.4 years) were enrolled in this study. Fracture union and concentric reduction of both the ulnotrochlear and radiocapitellar articulations were achieved in all patients. The mean ± SD follow-up was 31.6 ± 11.9 months. The mean ± SD arc of flexion-extension was 110.3° ± 26.3° and arc of forearm rotation was 139.5° ± 17.1°. The mean ± SD MEPS was 88.1 ± 12.2 points, with results classified as excellent in eight elbows, good in ten, and fair in four. Six patients had radiographic signs of post-traumatic arthritis. Three patients required secondary surgeries. Conclusion Combined surgical approaches can be considered for the treatment of terrible triad injuries in association with anteromedial coronoid fractures.

Acute septic arthritis of shoulder joint caused by Aeromonas veronii biotype sobria.

We present the case of a 91-year-old woman who presented with a 2­day history of progressive pain and immobility of the right shoulder joint after fever of unknown etiology. Aeromonas sobria was isolated from a culture of purulent synovial fluid. The clinical condition gradually improved with the application of appropriate antibiotics and no surgical intervention was necessary. This report indicates that acute septic arthritis may result from Aeromonas veronii biotype sobria infections in healthy people. This case is contrary to the previous reports due to the absence of obvious risk factors.

Operative treatment of terrible triad of the elbow with a modified Pugh standard protocol: Retrospective analysis of a prospective cohort.

The aim of the present study was to investigate the efficacy of the surgical treatment of terrible triad injuries of the elbow using a modified standard surgical approach, and treatment determined by the mode and mechanism of injury, and intraoperative findings.The study was a retrospective analysis of a prospective cohort of patients presenting with terrible triad injuries of the elbow, who underwent surgical treatment between July 2009 and January 2014. All patients were treated surgically according to a modified Pugh standard protocol. Elbow functional status and range of movements were evaluated at 3 months, 6 months, 1 year, and 2 years or more after surgery. Radiographic signs of post-traumatic arthritis were rated according to the Broberg and Morrey system.Our series included a final cohort of 29 males and 13 females with a mean age of 48.23 ±â€Š10.95 years at the time of injury. The mean follow-up period was 30.47 ±â€Š7.65 months. The mean flexion-extension arc was 107°â€Š±â€Š22°, and the average forearm rotation arc was 145°â€Š±â€Š14°. The mean Mayo Elbow Performance Score was 88 ±â€Š10 points (range 55 to 100 points), with excellent results in 24 elbows, good results in 16, and poor results in 2. Functional results of the elbow improved significantly from 3 months postoperatively (P < .05), but tended to plateau from 1 year after surgery. Thirteen patients had radiographic signs of arthrosis (9 grade 1, 4 grade 2). Postoperative complications were local infection around the incision (n = 1), transient postoperative median nerve paralysis (n = 1), and postoperative posterior interosseous nerve paralysis (n = 1). Four patients required further surgery. Five patients had evidence of heterotopic ossification.Overall, we show that slight modifications to Pugh standard protocol for the surgical treatment of terrible triad injuries can lead to good to excellent results, although there were a good number of complications. The ideal surgical approach and treatment should be based on the mode and mechanism of injury, and intraoperative findings, and modifying the standard surgical treatment approach for terrible triad elbow injuries may be beneficial.

[Research progress on pathogenesis of temporary osteoporosis in hip].

Transient osteoporosis of the hip(TOH) is classified as a type of bone marrow edema syndrome. TOH is lack of previous study and there is still controversy about his pathogenesis. In recent years, with the development of multi-discipline, such as imaging, pathology, molecular biology, the study has found that the pathological mechanism is complex, while its mechanism is still not clear, which need further research. This paper summarizes the research progress on the pathogenesis of TOH from neurogenic, osteonecrosis, abnormal vascular function, subchondral fracture, heredity and regional acceleration and son on.

Cerebral infarction due to malposition of cervical pedicle screw: A case report.

RATIONALE: Malposition of cervical pedicle screw (CPS) has a risk of vertebral artery (VA) injury which sometimes may cause unexpected and catastrophic outcome. A rare case of delayed onset of cerebral infarction caused by malposition of CPS was reported. PATIENT CONCERNS: A 23-year-old man who underwent a posterior cervical reduction and fusion of C4-5 using CPS fixation and allograft for cervical spine injury is presented. The patient suffered progressively weakness and numbness for both of upper and lower extremities 1 day after the operation. Computed tomography scans revealed bilateral occupation of the pedicle screws in the foramen of C4 and C5 and the magnetic resonance imaging (MRI) displayed several areas of infarction in the brainstem and cerebellum. DIAGNOSES: Plain radiographs of the cervical spine revealed the C4 vertebral body and MRI displayed a disruption of the anterior longitudinal ligament on the level of C4-5 and severe injury to the soft tissues of the cervical spine at admission. Brainstem and cerebellum infarction was diagnosed at postoperative. INTERVENTION: A revision surgery was decided to remove all of the pedicle screws and place lateral mass screws instead. OUTCOMES: The patient felt better on his all of 4 extremities following revision surgery. Fortunately, he was neurologically close to normal at a 3-month follow-up. LESSONS: Delayed onset of cerebral infarction is rarely reported complication caused by malposition of CPS. When a CPS perforates the transverse foramen and causes symptom of cerebral infarction, a revision surgery in time is strongly recommended to prevent further sequelae.

[Clinical observation of proximal femoral anti-rotation nail for the treatment of femoral intertrochanteric fracture].

OBJECTIVE: To explore the curative effect and the recessive loss of blooding of PFNA for the treatment of intertrochanteric fractures of femur. METHODS: From January 2012 to January 2015, a total of 49 patients with intertrochanteric fractures of femur were treated with proximal femoral anti-rotation nail including 41 males and 8 females with an average age of 79 years old ranging from 65 to 91 years old. According to the modified Evans type, 1 case was type I, 12 cases were type II, 36 cases were type III. All cases were fresh fractures. Patients had hip pain, movement limited, joint swelling, bruising, extorsion deformity, X-ray and CT examination showed completely fractures. All patients were treated by closed reduction and PFNA internal fixation. Three comminuted fractures using closed reduction were not satisfied, then were treated by limited PFNA fixation after open reduction. RESULTS: The patients' incision got the grade A healing, no complications such as infection and internal fixation failure happened. All patients were followed up from 6 to 36 months (means 22 months). The pain VAS score decreased from preoperative 7.70±1.97 to 1.00±0.26 at 6 months after operation(P<0.01). Harris hip score improved from preoperative 8.70±4.19 to 91.70±5.31 at 6 months after operation(P<0.01). The outcome at 6 months after operation was excellent in 34 cases, good in 7, poor in 1. The fracture healing time was from 8 to 16 weeks with an average of 12 weeks after operation. One patient with osteoporosis, crushing broken, poor compliance, associated with schizophrenia at the same time, appeared with the displacement of the femoral greater trochanter, with conservative treatment for healing. CONCLUSIONS: Intertrochanteric fractures of femur are common in the elderly trauma, in pain relief, recovery of hip function, to provide quality of life for the patients, PFNA achieved satisfactory effect, but its existence is worth to pay close attention to the recessive loss of blood.