Background. Inpatient dislocation after total hip arthroplasty (THA) is considered a non-reimbursable “never event” by the Centers for Medicare and Medicaid Services. There is extensive evidence that technical procedural factors affect dislocation risk, but less is known about the influence of non-technical factors. We evaluated inpatient dislocation trends following elective primary THA, and identified patient and hospital characteristics associated with the occurrence of dislocation. Methods. We used discharge records from the Nationwide Inpatient Sample (2002–2011). Temporal trends were assessed and multivariable logistic regression modeling was used to identify factors associated with dislocation. Results. The in-hospital dislocation rate increased from 0.025% in 2002 to 0.15% in 2011, despite a downward trend in length of stay (P<0.001). Patient characteristics associated with the occurrence of dislocation were black or Hispanic race/ethnicity, lower household income, and Medicaid insurance. Comorbidities associated with dislocation included hemiparesis/hemiplegia, drug use disorder, chronic renal failure, psychosis, and obesity. Dislocations were less likely to occur at teaching hospitals and in the South. Conclusion. The in-hospital dislocation rate following elective primary THA is increasing, in spite of shorter stays and surgical advances over time. Given the sociodemographic disparities in dislocation risk documented herein, interventions to address social determinants of health might do as much or more to reduce the occurrence of dislocation than technical improvements

Introduction. Total Knee Arthroplasty (TKA) is a proven successful and cost-effective method to relieve pain and improve joint function and quality of life in patients with advanced knee arthritis. However, after a TKA, only 75 to 89% of patients are satisfied. Since patient satisfaction is one of the main objectives of elective orthopaedic surgery, it is important to investigate the reasons for dissatisfaction and develop remedial strategies. Objectives. The aims of the current project are to investigate patient satisfaction after TKA and establish physical, mental and social determinants of patient satisfaction and overall socio-economic costs associated with unsatisfactory outcome. The global objective is to identify patients most likely to benefit from primary TKA, establish optimal evidence-based indications and timing for TKA, and address the necessity to educate patients preoperatively towards realistic expectations or propose alternative therapies. Based on the results, a composite score for patient selection will be developed using objective and subjective parameters. Cut-off values for acceptable indications for TKA will be proposed. Methods. General determinants of patient satisfaction are first investigated in a retrospective and prospective survey of TKA. Expectations regarding the global benefit of TKA, postoperative pain and difficulties are evaluated. Psychological tests assessing the ability of patients to cope with pain are performed. Objective clinical and radiographic parameters, patient reported outcomes and satisfaction are compared between subgroups based on (1) patient intrinsic factors such as gender and age, BMI, co-morbidities, general physical and mental health, activity, level of education and socio-economic situation, (2) implant factors, (3) surgery and surgical experience related factors. Subsequently, a randomized controlled trial of 330 consecutive primary TKAs using 3 contemporary implants of different design concepts will be carried out. Evaluation will be double-blinded (immediately preoperative randomisation, patient blinded, postoperative observer blinded). In addition, a surgeon's assessment of subjective technical difficulty will be performed. A university/teaching hospital setting will be compared with a private hospital and the influence of the surgeon on the level of patient satisfaction will be assessed. Results. Intermediate evaluation of the study revealed extensive logistic difficulties in setting up such a large scale trial and in motivating patients, nursing and medical staff to participate and sustain the necessary commitment and discipline to collect all necessary data at all follow-up intervals. Patients often felt overwhelmed by a multitude of clinical scores and technical assessments leading to a decrease in study compliance and rapid loss to follow-up. Motivation proved easier in a smaller private hospital environment. At the university hospital, patient involvement was enhanced by a personalized approach with information sessions in small groups. The introduction of a new software system with direct patient input via touch screens or remote online completion of scores reduced the data input burden. Scores are examined for simultaneous digital answering of overlapping questions. Conclusions. A large scale trial to investigate longer term patient satisfaction after TKA and establish its determinants involves continuous motivation and sustained discipline of patients and staff. A personalized approach and digital patient reported outcomes prove to maximize data acquisition