One case of suppurative acromioclavicular arthritis caused by Staphylococcus aureuswas reported. The patient was admitted to hospital due to swelling and pain in the right shoulder, limited mobility without no obvious cause.Through medical history, physical examination, imaging examination, and local tissue bacterial culture, it was confirmed that the infection was caused by Staphylococcus aureus. After surgery and anti infection treatment, satisfactory treatment results were achieved. Through literature review, 95 cases of suppurative acromioclavicular arthritis were retrieved and analyzed from 57 articles.Among them, 26 cases (27%) were infected with Staphylococcus aureus, including 3 cases of clearly identified methicillin-resistant Staphylococcus aureus, 2 cases of methicillin-sensitive Staphylococcus aureus, and 1 case of methicillin-resistant Staphylococcus epidermidis; 13 cases (14%) of Streptococcus; There were 6 cases (6%) of special pathogens, including 2 cases of Haemophilus parainfluenzae, 1 case of Candida, 1 case of Bacillus pallidum, 1 case of Mycobacterium avium, and 1 case of Pasteurella multocida; 50 cases (53%) of specific infections with pathogens were not clearly reported. Suppurative acromioclavicular arthritis has the characteristics of difficult early diagnosis, rapid disease progression, and strong destructiveness. MRI and ultrasound have high specificity and sensitivity in the diagnosis of this disease, and ultrasound can assist in obtaining joint fluid for examination. Early identification of the pathogen is the key to the treatment of this disease. Before identifying the pathogen, antibiotics should not be used arbitrarily. After diagnosis, timely anti infection treatment should be carried out, and if necessary, surgical debridement should be performed. The vast majority of patients can achieve satisfactory and accurate treatment results after active and standardized treatment.

Objective:To establish a classification system for the repair band in the subchondral bone origination point in MRI for traumatic osteonecrosis of the femoral head (ONFH) and preliminarily explore the correlation between this classification and the progression of femoral head collapse.Methods:A retrospective analysis was conducted on 73 cases of traumatic ON-FH treated at the Quanzhou Orthopedic-traumatological hospital from January 2000 to December 2019. Among them, there were 46 males and 27 females with an average age of 34.9±8.3 years (range 19-55 years). Clinical and radiological data such as age, gender, side, fracture classification, reduction quality, JIC classification, and bone repair band (BRB) classification were recorded. The progression of traumatic ONFH was assessed using the ARCO staging system, with stages IIIA and IIIB defined as mild collapse and progressive collapse, respectively. The BRB classification was established based on MRI findings, and the inter- and intra-observer consistency of the BRB classification was analyzed using Kappa test. The correlation between the BRB classification and progressive femoral head collapse was analyzed using the Kaplan-Meier survival curve and binary variable Cox regression analysis.Results:According to the BRB classification, 73 cases were divided into type 1 with superficial lesion in 38.4%, type 2 with uncertain lesion in 21.9%, and type 3 with extensive lesion in 39.7%. The inter-observer consistency Kappa value for the BRB classification was 0.798, and the intra-observer consistency Kappa value was 0.896, indicating a high level of consistency. A follow-up of 73 cases (54.8±34.9 months, range 24-165 months) showed a significant correlation between the BRB classification and ARCO staging at the last follow-up (χ 2=37.556, P<0.001), with progression to stages IIIA and IIIB as follows: type 1 had 3 and 1 cases, type 2 had 4 and 1 cases, and type 3 had 14 and 12 cases, respectively. Using the occurrence of progressive collapse (stage IIIB) as the endpoint, the risk of progression to stage IIIB for type 2 was not statistically different from type 1 [ HR=1.766, 95% CI (0.465, 6.702), P=0.403]; the risk of progression to stage IIIB for type 3 was significantly higher than for type 1 [ HR=15.126, 95% CI (4.708, 48.592), P<0.001]. Conclusion:The BRB classification is closely related to the progression of traumatic ONFH and is an independent risk factor for predicting the occurrence of progressive collapse; this classification is helpful for early diagnosis and predicting the progression of collapse and treatment plan decision-making.

ObjectiveTo propose a three-degree-of-freedom model of electric wheelchair, to optimize the steering stability of the wheelchair. MethodsBased on the two degrees of freedom vehicle model and considering the influence of body inertia and lateral wind, the wheelchair roll angle was introduced to establish the three degrees of freedom steering model of wheelchair. The lateral velocity, centroid sideslip angle, yaw rate and body roll angle response of the motor angular velocity input under different working conditions were simulated and analyzed respectively. Taking KS2 electric wheelchair as an example, the wheelchair steering experiment was designed to verify the rationality and feasibility of the model, and the optimization effect of the model algorithm on the wheelchair handling and stability. ResultsThe maneuverability and stability of the electric wheelchair with three degrees of freedom model algorithm were significantly improved, and the response curve was smoother. The smaller the |V_L-V_R|/t was, the better the handling stability was when the left and right motors of the wheelchair had the same steering direction. When |V_L-V_R|/t was the same, the steering maneuverability was better on the reverse rotation of the motor, but the handling stability also decreased. ConclusionThe simulation analysis is in good agreement with the experimental results, which verifies that the model is reasonable and feasible. The model algorithm can better optimize the handling stability of electric wheelchairs, and can be generally applied to study and analyze the handling stability of different wheelchairs when they turn.