Neuronal dynamics direct cerebrospinal fluid perfusion and brain clearance.

The accumulation of metabolic waste is a leading cause of numerous neurological disorders, yet we still have only limited knowledge of how the brain performs self-cleansing. Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain. These waves are a plausible mechanism to explain the correlated potentiation of the glymphatic flow1,2 through the brain parenchyma. Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma. Notably, synthesized waves generated through transcranial optogenetic stimulation substantially potentiated cerebrospinal fluid-to-interstitial fluid perfusion. Our study demonstrates that neurons serve as master organizers for brain clearance. This fundamental principle introduces a new theoretical framework for the functioning of macroscopic brain waves.

The safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine among patients undergoing elective surgery for closed fractures: A randomized, double-blind, placebo-controlled, multicenter phase 2 clinical trial.

BACKGROUND: Vaccines are urgently required to control Staphylococcus aureus hospital and community infections and reduce the use of antibiotics. Here, we report the safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine (rFSAV) in patients undergoing elective surgery for closed fractures. METHODS: A randomized, double-blind, placebo-controlled, multicenter phase 2 clinical trial was carried out in 10 clinical research centers in China. Patients undergoing elective surgery for closed fractures, aged 18-70 years, were randomly allocated at a ratio of 1:1 to receive the rFSAV or placebo at a regimen of two doses on day 0 and another dose on day 7. All participants and investigators remained blinded during the study period. The safety endpoint was the incidence of adverse events within 180 days. The immunogenicity endpoints included the level of specific antibodies to five antigens after vaccination, as well as opsonophagocytic antibodies. RESULTS: A total of 348 eligible participants were randomized to the rFSAV (n = 174) and placebo (n = 174) groups. No grade 3 local adverse events occurred. There was no significant difference in the incidence of overall systemic adverse events between the experimental (40.24 %) and control groups (33.72 %) within 180 days after the first immunization. The antigen-specific binding antibodies started to increase at days 7 and reached their peaks at 10-14 days after the first immunization. The rapid and potent opsonophagocytic antibodies were also substantially above the background levels. CONCLUSIONS: rFSAV is safe and well-tolerated in patients undergoing elective surgery for closed fractures. It elicited rapid and robust specific humoral immune responses using the perioperative immunization procedure. These results provide evidence for further clinical trials to confirm the vaccine efficacy. China's Drug Clinical Trials Registration and Information Publicity Platform registration number: CTR20181788. WHO International Clinical Trial Registry Platform identifier: ChiCTR2200066259.

[Effectiveness of arthroscopic "hybrid" suture for delaminated rotator cuff tear: A prospective randomized controlled study].

Objective: To investigate the effectiveness of "hybrid" suture with en masse combined with double-layer repair under arthroscopy in repair of delaminated rotator cuff tear by comparison with en masse suture. Methods: Fifty-six patients with delaminated rotator cuff tears met selection criteria between June 2020 and January 2022 were included in the study. Patients were divided into two groups ( n=28) using a random number method. The patients in trial group underwent arthroscopic "hybrid" suture with the combination en masse and double-layer suture. The patients in control group underwent en masse suture under arthroscopy. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, rotator cuff tear side, tear size, cause of injury, disease duration, and preoperative American Association of Shoulder and Elbow Surgeons (ASES) score, the University of California at Los Angeles (UCLA) shoulder scoring, visual analogue scale (VAS) score, and shoulder range of motion (forward flexion and lateral external rotation). The operation time, the difference of ASES score, UCLA score, VAS score, and shoulder range of motion (forward flexion and lateral external rotation) between pre- and post-operation were recorded and compared between the two groups ( P>0.05). The rotator cuff healing was examined by MRI and evaluated based on the classification criteria of rotator cuff healing proposed by Sugaya et al. Results: Three cases (1 case in the trial group and 2 cases in the control group) were excluded from the study due to loss of follow-up. Twenty-seven cases in the trial group and 26 cases in the control group were included in the final study analysis. All operations of the two groups were completed successfully. There was no significant difference in the operation time between groups ( P>0.05). The follow-up time was 10-12 months (mean, 10.9 months) in the trial group and 10-13 months (mean, 11.4 months) in the control group. All incisions healed by first intention. No surgery-related complications occurred. The UCLA score, ASES score, VAS score, and shoulder range of motion (forward flexion and lateral external rotation) of both groups at 9 months after operation were significantly superior to those before operation ( P<0.05). The difference of UCLA score, ASES score, and VAS score between before and after operation in the trial group were significantly better than those in the control group ( P<0.05). There was no significant differences between the two groups in the difference of shoulder range of motion (forward flexion and lateral lateral rotation) ( P>0.05). At 9 months after operation, according to the classification criteria of rotator cuff healing proposed by Sugaya et al, MRI showed that the rotator cuff healing of the trial group was significantly better than that of the control group ( P<0.05). Conclusion: Compared with en masse suture, arthroscopic "hybrid" suture for the repair of delaminated rotator cuff tear has advantages in relieving pain and improving shoulder joint function, and the rotator cuff healing is better.

[Effect of freshening technique on docking site in tibial bone transport management].

OBJECTIVE: To study the effect of freshening technique on docking site in tibial bone transport management. METHODS: Retrospective cohort study was conducted about the effect of freshening technique on docking site in 20 cases(15 males and 5 females) treated with tibial bone transport from January of 2014 to December of 2019. The age of patients ranged from 19 to 62 years old, with an average of (42.3±11.5)years old. Seven patients had infectious bone defect and 13 patients had non-infectious. Application of freshening technique immediately after docking included resection of invaginated skin or soft tissue, removal of closed sclerotic bone, re-apposition, increasing the contact, acute compression of freshened docking site and grafting from adjacent medullary or bone debris, followed by post-operative gradual compression. RESULTS: The amount of segmented bone defect ranged from 5 to 15 cm, with an average of(9.2±2.9) cm. Time required from osteotomy to contact of butt end ranged from 26 to 243 days, with an average of(109.1±51.1) days. The duration needed from 3 to 7 months with an average of(3.7±1.1) months before reaching radiological healing criterion in docking site. Fourteen out of 15 concurrent fibular osteotomy were united. Consolidation time for distracted callus ranged from 5 to 28 months, with an average of (15.0±6.5) months. Bone healing index(BHI) ranged from 0.8 to 2.8 months/cm, with an average of (1.6±0.5) months. One surgical site infection (5%) in tibial was noted. No refractures were found in follow-up ranged from 12 to 73 months, with an average of(37.6±20.3) months after fixator removal. CONCLUSION: Freshening technique immediately after docking had advantages of the shorter healing time, avoidance of refracture, and independance of necessity for remote autograft harvest.

All-cause mortality risk in older patients with femoral neck fracture.

INTRODUCTION: The mortality rate after hip fracture is high. However, the 1-year mortality rate after femoral intertrochanteric fracture and femoral neck fracture differs (Gibson-Smith D, Klop C, Elders PJ, Welsing PM, van Schoor N, Leufkens HG, et al., Osteoporos Int 25:2555-2563, 2014), although both are types of hip fracture. A previous real-world single-center prospective cohort study showed that older age and high Charlson comorbidity index score were risk factors for femoral intertrochanteric fracture. Additionally, therapy with zoledronic acid 5 mg (Aclasta) was a protective factor (Li XP, Zhang P, Zhu SW, Yang MH, Wu XB, Jiang XY, J Orthop Surg Res. 16:727, 2021). We wished to determine the risk factors for all-cause mortality in femoral neck fracture patients. AIM: To identify the risk factors for postoperative all-cause mortality in aged patients with femoral neck fracture. MATERIALS AND METHODS: We enrolled 307 aged patients with femoral neck fracture; 38 were lost to follow-up after 2-3 years. The patients' general characteristics, bone mineral density, and anti-osteoporosis treatment after operation were recorded as potential risk factors. Kaplan-Meier curves and multivariate Cox proportional hazards models were constructed to analyze the influence of each factor on all-cause mortality. RESULTS: This was a real-world single-center prospective cohort study showing that (1) most of the patients who died were male, older (mean age of the patients who died: 84.8 years vs. 77.9 years for survivors), and had more comorbidities compared with surviving patients. Previous fracture history, body mass index, femoral neck T score, hemoglobin and 25-hydroxy vitamin D levels did not differ significantly between patients who died vs. survived. (2) Differing from patients with intertrochanteric fractures, older patients with femoral neck fracture experienced no reduction in all-cause mortality with treatment with zoledronic acid. CONCLUSION: In Chinese patients with femoral neck fracture, physicians should pay careful attention to male patients, older patients, and those with high numbers of comorbidities.

All-cause mortality risk in aged femoral intertrochanteric fracture patients.

INTRODUCTION: The 1-year mortality rate after femoral intertrochanteric fracture is higher than that of femoral neck fracture, which also belongs to hip fracture (Cui et al. in Arch Osteoporos 14(1):55, 2019). With the application of the concept of co-management model of orthopedics and geriatrics, the short-term and long-term mortality of all types of hip fractures has decreased (Van Heghe et al. in Calcif Tissue Int, 2021, https://doi.org/10.1007/s00223-021-00913-5 ). However, the mortality of Chinese femoral intertrochanteric fracture patients under this model has not been reported in the literatures. AIM: This paper aims to study the risk factors of postoperative all-cause mortality in aged patients with femoral intertrochanteric fracture under the co-management model of orthopedics and geriatrics. MATERIALS AND METHODS: This is a single-center prospective cohort study based on the real world, under the co-management of orthopedics and geriatrics, 363 patients aged ≥ 65 years with femoral intertrochanteric fracture were enrolled and followed up for 2-3 years; 52 patients were lost to follow up. Age, gender, body mass index (BMI), history of comorbidities, hip Bone Mineral Density (BMD), fracture history, 25(OH)D level, hemoglobin level, anti-osteoporosis treatment were risk factors to be tested. Kaplan-Meier survival curves and multivariate Cox proportional hazards models were constructed to analyze the impact of factors on all-cause mortality. RESULTS: (1) Most of the dead patients were older (the mean age was 83.4 years, compared with 79.8 years for surviving patients), with more complications and without anti-osteoporosis medication; gender, pre-fracture history, BMI, total hip BMD, hemoglobin, 25(OH)D had no difference between the dead and the living patients. (2) Elderly patients with Intertrochanteric fracture can benefit from the early treatment of Zoledronic Acid (within 3 days after the operation). CONCLUSION: Under the co-management of orthopedics and geriatrics, to Chinese patients with Femoral Intertrochanteric fracture, Doctors should pay more attention to their age and chronic disease, and give anti-osteoporosis treatment if allowed.

Management of Locked Posterior Shoulder Dislocation with Reverse Hill-Sachs Lesions via Anatomical Reconstructions.

OBJECTIVE: To evaluate the outcomes of locked posterior shoulder dislocation with reverse Hill-Sachs lesions in patients treated with anatomical reconstructions. METHODS: Patients who were treated at our institution between January 2016 and June 2020 were retrospectively reviewed. The demographics of the patients including gender, age, occupation, and dominant arm were recorded. Eleven cases from 10 patients qualified in this study. Nine males and one female were included. The mean age of the patients was 44.8 years (range, 33-54 years). Mechanism of injury, duration between injuries and definitive diagnosis, misdiagnosis, size of humeral head impaction, treatment maneuver, and details of operation performed were reviewed. Plain radiographs and computed tomography (CT) scan were taken to determine the size of defects preoperatively and fracture healing during follow-up. During surgery, the deltopectoral approach was employed. Anatomical reconstruction procedure including reduction, disimpaction, bone grafting, and fixation were sequentially performed. Either cancellous autograft from iliac crest or allograft were used and the fractures were anatomically reduced and stabilized by screws or plates. Visual Analog Scale (VAS) and Constant-Murley score were recorded to determine the functional outcomes preoperatively, at 3 months and 6 months postoperatively, and at the last follow-up. The range of motion in forward flexion was recorded at 6 months follow-up postoperatively. RESULTS: Causes of injuries included epileptic seizure in four cases, fall in three cases, and road traffic accident in three cases. Misdiagnoses occurred in five out of 10 patients. The mean time between injury and definitive treatment among those misdiagnosed was 112 days. The mean size of the impacted reverse Hill-Sachs lesions was 33.95% (range, 19.1%-42.6%). All patients received surgical management with anatomical reconstruction approach, including open reduction, disimpaction, bone grafting, and internal fixation. The mean amount of bleeding during operation was 450 mL. The mean follow-up period was 22.6 months. Fracture healing was observed by 8 weeks in all cases postoperatively and evidence of bone grafting could not be further detected on CT scan at 6 month during follow-up. VAS was significantly lower at the last follow-up (0.68 ± 0.21) in comparison to preoperative scores (4.96 ± 0.97) (P < 0.05). Constant-Murley was improved significantly at the last follow-up (91.7 ± 8.3) in comparison to that preoperatively (40.6 ± 10.3) (P < 0.05). The mean range of motion in forward flexion was 38.25° ± 9.36° preoperatively and significantly improved to 162.48° ± 12.68° at 6-month follow-up (P < 0.05). CONCLUSION: The anatomical reconstruction procedure by open reduction and bone augmentation for the treatment of locked posterior shoulder dislocation with reverse Hill-Sachs lesion was promising in both fracture healing and functional outcomes.

Lateral minimal approach to the terrible triad of the elbow: a treatment protocol in Beijing Jishuitan Hospital.

BACKGROUND: This study aimed to report the surgical techniques and results of treating coronoid process and radial head fracture combined with dislocation of the elbow (terrible triad of the elbow) using a single lateral incision, known as the extensor digitorum communis (EDC) split approach. METHODS: A retrospective analysis was performed of 109 patients with terrible triad of the elbow who had been treated by the authors from January 2013 to December 2019. The participants included 67 males and 42 females, with a mean age of 42.2 years (14-71 years). All participants were treated via a single lateral approach. The coronoid process was fixated with Kirschner wires combined with anterior capsule suture lasso fixation. For the radial head fracture, 58 cases were fixated by AO headless cannulated screw (AO HCS) and 51 cases by acumed radial head replacement. In repair of the lateral collateral ligament (LCL) complex and the common extensor tendon, 28 cases used ETHIBOND suture through bone holes at the humeral lateral epicondyle, and the other 81 cases used suture anchors. No medial collateral ligament was repaired. A total of 46 participants were fixated with a Stryker dynamic joint distractor (DJD) II hinged external fixator to protect the bone and soft tissue. RESULTS: All participants were followed up from 6 to 60 months (mean, 36.1 months). Their elbow range of flexion and extension averaged 123.4°±20.7°, forearm rotation 151.0°±25.6°, and Mayo elbow performance score (MEPS) 92.3±8.8. There were 22 participants (19.5%) with ulnar nerve symptoms, 16 (14.7%) who had elbow stiffness, and 7 underwent secondary surgery, including 6 removals of internal fixation, 5 arthrolyses of the elbow, and 2 ulnar neurolyses. CONCLUSIONS: Coronoid fractures, radial head fractures, and LCL injuries of the terrible triad of the elbow can be treated satisfactorily through a lateral minimal incision, combined with a hinged external fixation if necessary.

Electromechanical impedance based self-diagnosis of piezoelectric smart structure using principal component analysis and LibSVM.

The long-term use of a piezoelectric smart structure make it difficult to judge whether the structure or piezoelectric lead zirconate titanate (PZT) is damaged when the signal changes. If the sensor fault occurs, the cases and degrees of the fault are unknown based on the electromechanical impedance method. Therefore, after the principal component analysis (PCA) of six characteristic indexes, a two-component solution that could explain 99.2% of the variance in the original indexes was obtained to judge whether the damage comes from the PZT. Then LibSVM was used to make an effective identification of four sensor faults (pseudo soldering, debonding, wear, and breakage) and their three damage degrees. The result shows that the identification accuracy of damaged PZT reached 97.5%. The absolute scores of PCA comprehensive evaluation for structural damages are less than 0.5 while for sensor faults are greater than 0.6. By comparing the scores of the samples under unknown conditions with the set threshold, whether the sensor faults occur is effectively judged; the intact and 12 possible damage states of PZT can be all classified correctly with the model trained by LibSVM. It is feasible to use LibSVM to classify the cases and degrees of sensor faults.

Olecranon osteotomy vs. triceps-sparing for open reduction and internal fixation in treatment of distal humerus intercondylar fracture: a systematic review and meta-analysis.

BACKGROUND: The open reduction and internal fixation (ORIF) was a standard treatment approach for fracture at distal humerus intercondylar, whereas the optimal way before ORIF remains inconclusive. We, therefore, performed a systematic review and meta-analysis to assess the efficacy and safety of olecranon osteotomy vs. triceps-sparing approach for patients with distal humerus intercondylar fracture. METHODS: The electronic searches were systematically performed in PubMed, EmBase, Cochrane library, and Chinese National Knowledge Infrastructure from initial inception till December 2019. The primary endpoint was the incidence of excellent/good elbow function, and the secondary endpoints included Mayo elbow performance score, duration of operation, blood loss, and complications. RESULTS: Nine studies involving a total of 637 patients were selected for meta-analysis. There were no significant differences between olecranon osteotomy and triceps-sparing approach for the incidence of excellent/good elbow function (odds ratio [OR]: 1.37; 95% confidence interval [CI]: 0.69-2.75; P = 0.371), Mayo elbow performance score (weight mean difference [WMD]: 0.17; 95% CI: -2.56 to 2.89; P = 0.904), duration of operation (WMD: 4.04; 95% CI: -28.60 to 36.69; P = 0.808), blood loss (WMD: 33.61; 95% CI: -18.35 to 85.58; P = 0.205), and complications (OR: 1.93; 95% CI: 0.49-7.60; P = 0.349). Sensitivity analyses found olecranon osteotomy might be associated with higher incidence of excellent/good elbow function, longer duration of operation, greater blood loss, and higher incidence of complications as compared with triceps-sparing approach. CONCLUSIONS: This study found olecranon osteotomy did not yield additional benefit on the incidence of excellent/good elbow function, while the duration of operation, blood loss, and complications in patients treated with olecranon osteotomy might be inferior than triceps-sparing approach.

[Treatment progress on proximal humerus fracture with proximal humerus cage].

Proximal humerus fracture is one of the common shoulder fractures. With the increase in incidence, the proportion of surgical intervention is increasing. This paper explores the traditional and new treatment methods for proximal humerus fracture. Locking plate technology is the most commonly used method in the clinic, but its complication rate of intra-articular screw penetration and reoperation is too high.Fibular strut allografts can provide adequate support, but it is a significant trauma surgery and has a high incidence of potential disruption to necessary vascular.Arthroplasty is one of the treatments for complex proximal humerus fractures, but it has a long learning curve and high cost.In recent years, the proximal humerus cage's intervention model has emerged, which has the inherent advantagesof a three dimensional structure, which can provide adequate load bearing support for the humeral head and provide flexible screw placement Angle. The cage offers a new technical option to reduce postoperative complications and improve patients' rehabilitation safety. A comprehensive grasp of the treatments of proximal humerus fracture and rational choice of intervention measures will benefit patients.

[Progress on diagnosis and treatment of low transcondylar fractures of distal humerus].

Low transcondylar fractures of the distal humerus in adults is rarely seen and reported in literatures. It has a bimodal distribution in terms of age, affecting the elderly and younger patients. The fracture is characterized by a very low transverse intra-capsular and extra-articular fracture lines extending from the level of lateral epicondyle to medial epicondyle. Standard elbow plain films and CT scans are crucial and indispensable for diagnosis. Conservative treatment is suitable for undisplaced fractures, patients who are intolerant of anesthesia, or people with advanced dementia. Open reduction and internal fixation (ORIF) is preferred. Parallel and orthogonal plate fixation are widely adopted while some researchers preferred crisscross-type screw fixation or bicolumnar 90-90 plating. In addition, some customized posterolateral plates are specially designed to be able to insert a transverse screw, functioning as lateral support. However, most of the recent researches conducted on low transcondylar fractures of the distal humerus are retrospective studies with relatively lower level of evidence compared to prospective and randomized controlled ones which remain a vacancy in this field. Therefore, further studies comparing the biomechanical properties and clinical prognosis of different configurations of internal fixation or total elbow arthroplasty for the treatment of low transcondylar fractures are needed in the future.

A Common Neuroendocrine Substrate for Diverse General Anesthetics and Sleep.

How general anesthesia (GA) induces loss of consciousness remains unclear, and whether diverse anesthetic drugs and sleep share a common neural pathway is unknown. Previous studies have revealed that many GA drugs inhibit neural activity through targeting GABA receptors. Here, using Fos staining, ex vivo brain slice recording, and in vivo multi-channel electrophysiology, we discovered a core ensemble of hypothalamic neurons in and near the supraoptic nucleus, consisting primarily of neuroendocrine cells, which are persistently and commonly activated by multiple classes of GA drugs. Remarkably, chemogenetic or brief optogenetic activations of these anesthesia-activated neurons (AANs) strongly promote slow-wave sleep and potentiates GA, whereas conditional ablation or inhibition of AANs led to diminished slow-wave oscillation, significant loss of sleep, and shortened durations of GA. These findings identify a common neural substrate underlying diverse GA drugs and natural sleep and reveal a crucial role of the neuroendocrine system in regulating global brain states. VIDEO ABSTRACT.

[Is anterior transposition of ulnar nerve beneficial during open reduction and internal fixation for intercondylar humerus fractures].

OBJECTIVE: To compare activity, function and postoperative ulnar nerve function of elbow joint by anterior transposition of ulnar nerve or not during open reduction and internal fixation for intercondylar humerus fractures. METHODS: From January 2013 to May 2017, 168 patients with intercondylar humerus fractures were treated surgically with open reduction and internal fixation (ORIF). The patients were divided into anterior subcutaneous transposition group and simple decompression group according to handling method of ulnar nerve. There were 48 patients in transposition group, including 23 males and 25 females with an average age of (42.5±15.7) years old ranging from 14 to 77 years old, and ulnar nerve treated enough free and anterior subcutaneous transpostion after reduction of intercondylar humerus fractures; while there were 120 patients in simple decompression group, including 62 males and 58 females with an average age of (43.4±17.3) years old ranging from 14 to 81 years old, ulnar nerve returned to sulci nervi ulnaris. Activity of flexion and extension of elbow joint, range of rotation of forearm were recorded at the latest following-up, Mayo score of elbow joint was used to evaluate clinical effect, McGowan grading was used to assess dysfunction of unlnar nerve. RESULTS: There was 1 patient delayed union, and 2 patients occurred joint stiffness in transposition group; while 1 patient suffered from incision infection, 1 fracture nonunion, and 4 joint stiffness in simple decompression group; and there was no statistical difference between two groups(P>0.05). Forty-eight patients in transposition group were followed-up from 12 to 59 months with an average of (32.2±14.2) months, activity of flexion and extension of elbow joint was (116±28)°, range of rotation of forearm was (152±12)°, MEPS score was 88.6±11.6; and 28 patients got excellent results, 16 good, 3 moderate and 1 poor. There were 17 patients occurred injury of ulnar nerve, and 7 patients still occurred dysfunction of ulnar nerve, and 6 patients were grade I, 1 patient was grade II according to McGowan grading. In simple decompression group, there were 120 patients were followed-up from 13 to 61 months with an average of (32.0±14.9) months, activity of flexion and extension of elbow joint was (119±27)°, range of rotation of forearm was (154±16)°, MEPS score was 88.9±12.5; and 67 patients got excellent results, 44 good, 7 moderate and 2 poor. There were 42 patients occurred injury of ulnar nerve, and 22 patients still occurred dysfunction of ulnar nerve, and 18 patients were grade I, 4 patients were grade II according to McGowan grading. There were no statistical differences in following time, activity of flexion and extension of elbow joint, range of rotation of forearm, MEPS score and dysfunction of ulnar nerve. CONCLUSIONS: Whether anterior transposition of ulnar nerve or not has no clarified effects for open reduction and internal fixation for intercondylar humerus fractures.

[Clinical observation of olecranon sled for the treatment for olecranal fracture].

OBJECTIVE: To explore clinical effect of olecranon sled in treating olecranal fracture. METHODS: Four patients with olecranal fracture treated by olecranon sled in March 2017, including 2 males and 2 females, age of 40, 46, 47, 72 years old, 3 patients on the left side and 1 patient on the right side. All patients were caused by falling down. Fracture were transverse, oblique and slightly compressive articular surface fracture. The time from injury to operation ranged from 1 to 3 days. Operative time, blood loss, complications and flexion and extension of elbow joint, and function of forearm were observed, VAS score was used to evaluate relieve degree of pain, and Mayo score was applied to assess recovery of elbow function. RESULTS: Four patients were followed up until September 2018. Operative time ranged from 40 to 60 min, blood loss was for 20 to 40 ml, and no complications occurred. All fracture were healed at 4 months after operation. Elbow flexion was for 140° to 150°, extension of elbow was from 0° and extend to 10°, activity of flexion and extension ranged from 140 ° to 160°, MEPS score was 100. No pain occurred during doing activity, and VAS score was 0. CONCLUSIONS: Low-profile design and integrated design of olecranon sled could avoid irritation of tension band and plate, and it is a simple and ideal internal fixation method for simple and mildly comminuted olecranon fracture, which is not suitable for severely comminuted olecranon fracture.

[Clinical outcomes of open reduction and internal fixation in treating Gustilo typeI and II patients with open distal humeral fractures].

OBJECTIVE: To analysis clinical effects of open reduction and internal fixation in treating Gustilo type I and II patients with open distal humeral fracture. METHODS: From 2013 May to 2017 June, 24 patient with Gustilo grade I and II open distal humeral fractures were treated with open reduction and internal fixation, including 20 males and 4 females, aged from 14 to 65 years old with an average of (41.3±13.1) years old. According to Gustilo classification, 16 patients were type I, 8 patients were typeII. Range of motion, complications and secondary surgery were recorded; elbow function were evaluated with VAS (visual analogue scale), MEPS (Mayo elbow performance score) and QuickDASH (quick disabilities of the arm, shoulder, and hand) at 12 months after operation. RESULTS: All patients were followed up from 15 to 60 years with an average of (34.1±11.9) months. VAS score was 0(0, 2); flexion and extension ranged from 50 °to 145° with an average of (115.2±26.1)°; the range of rotation ranged from 100° to 160° with an average of (147.7±17.0)°. MEPS score was for 75 to 90 (90.0±9.1), and 14 patients got excellent result, 10 patients moderate. Quick DASH score was 4.6(0, 14.8). There were 22 patients occurred complications, such as ulnar nerve symptom and internal fixation irritation, and 10 patients accepted the second operation. CONCLUSIONS: Open reduction and internal fixation is a safe and efficient method in treating Gustilo type I and II patients with open distal humeral fractures, which has an advantages of good range of movement and function score.