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Concept: John Charnley

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A variety of patient-related outcome questionnaires have been used for the assessment of results of total hip replacement. Generic core scales (SF-12, SF-36) and disease-specific scales like: Harris Hip Score, Western Ontario and McMaster University Osteoarthritis Index, Hip dysfunction and Osteoarthritis Outcome Score, Oxford Hip Score, American Academy of Orthopedic Surgeons hip and knee Questionnaire, Lower Extremity Functional Scale are used most frequently. Even though all of them were assessed in terms of construct and content validity, reproducibility and sensitivity, there are still some problems related to bias when total hip replacement evaluation is performed in the presence of comorbidities, contralateral hip disease and ceiling effect influencing the final score. As a result, there is a need for development of a new PRO questionnaire in order to improve total hip replacement assessment, enable early detection of postoperative complications or to evaluate the results of surgery in both hips separately. It is crucial that such measuring device has to be deprived of the influence of irrelevant factors on the final score.

Concepts: Assessment, Psychometrics, Hip replacement, Hip, Pelvis, Orthopedic surgery, Joint replacement, John Charnley

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INTRODUCTION: Hyperfibrinolysis is observed during and immediately after major orthopedic surgery. The kinetics and duration of this phase should be defined to adjust the duration of antifibrinolytic treatment with tranexamic acid (TXA). OBJECTIVE: We aimed to quantify the duration of postoperative fibrinolysis and to assess the biological impact of TXA administration. MATERIALS AND METHODS: Fourteen patients undergoing total hip replacement (THR) and 10 patients undergoing total knee replacement (TKR) with tourniquet were included in an observational, prospective, single-center study. Among these patients, 7 THR patients and 5 TKR patients received TXA (15mg/kg IV intraoperatively, followed by continuous infusion of 15mg/kg/h until end of surgery, then every 4hours until 16±2hours after surgery). D-dimers, euglobulin lysis time (ELT), and thrombin generation time (TGT) were measured prior to surgery as well as 6, 18 and 24hours (H) after. RESULTS: No significant difference in ELT was observed between the groups. In contrast, D-dimers significantly increased postoperatively in patients not treated with TXA (p<0.001), while such an increase was prevented in patients receiving TXA, as measured at H0, H6, H18 and H24 after THR, and at H6 and H18 after TKR (p<0.001). No significant between-group change in TGT, was observed (peak thrombin and endogenous thrombin potential) all along the study. CONCLUSION: This study shows that fibrinolysis peaked 6hours after end of surgery and maintained about 18hours after surgery, as evidenced by an increase in D-dimers. When administered for up to 16±2hours after surgery, TXA reduced postoperative fibrinolysis.

Concepts: Hip replacement, Orthopedic surgery, Joint replacement, Knee replacement, Polyethylene, Antifibrinolytic, John Charnley

25

Tranexamic acid (TXA) is an antifibrinolytic drug used to reduce bleeding in mortality risk situations such as trauma, cardiovascular surgery, and orthopedic surgery. The objective is to evaluate the effectiveness and safety of TXA in reducing surgery bleeding in hip arthroplasty through a systematic review of literature.

Concepts: Carbon dioxide, Blood, Hip replacement, Orthopedic surgery, Joint replacement, Tranexamic acid, Antifibrinolytic, John Charnley

6

Some employers are implementing reference-pricing benefit designs, which establish limits on the amount they will pay for some procedures covered by employer-sponsored insurance. Employees are required to pay the difference between the employer’s contribution limit and the actual price received by the hospital. These initiatives encourage patients to select low-price facilities and indirectly encourage facilities to reduce prices to increase patient volume. We evaluated the impact of reference pricing on the use of and prices paid for knee and hip replacement surgery by members of the California Public Employees' Retirement System (CalPERS) from 2008 to 2012, using enrollees in Anthem Blue Cross as a comparison group. In the first year after implementation, surgical volumes for CalPERS members increased by 21.2 percent at low-price facilities and decreased by 34.3 percent at high-price facilities. Prices charged to CalPERS members declined by 5.6 percent at low-price facilities and by 34.3 percent at high-price facilities. Our analysis indicates that in 2011 reference pricing accounted for $2.8 million in savings for CalPERS and $0.3 million in lower cost sharing for CalPERS members.

Concepts: Hospital, Hip replacement, Hip, Orthopedic surgery, Joint replacement, Employment, Price, John Charnley

4

Although life expectancy continues to increase worldwide and advances occur in surgical techniques and medical treatment, the chronological age limit for patients to undergo elective major orthopaedic procedures remains a controversial subject. The purpose of this study was to examine the trends in the incidence and in-hospital outcomes of elective major orthopaedic surgery in patients eighty years of age and older in the United States as a whole.METHODS: ICD-9-CM (International Classification of Diseases, 9th Revision, Clinical Modification) codes were used to identify patients at least eighty years of age in the Nationwide Inpatient Sample who underwent spinal fusion, total hip arthroplasty, or total knee arthroplasty from 2000 to 2009. Demographic data regarding the patient and health-care system were retrieved and analyzed.RESULTS: From 2000 to 2009, there were increasing trends in the age-adjusted incidence of spinal fusion, total hip arthroplasty, and total knee arthroplasty in patients at least eighty years of age (rate per 100,000 per year, 40 to 102 for spinal fusion, 181 to 257 for total hip arthroplasty, and 300 to 477 for total knee arthroplasty; p ≤ 0.001 for each). The overall in-hospital complication rate remained stable over time for spinal fusion and total knee arthroplasty and increased for total hip arthroplasty (9.0% to 10.3%, p = 0.008). The in-hospital mortality rate decreased over time (1.1% to 0.6% for spinal fusion, 0.5% to 0.3% for total hip arthroplasty, and 0.3% to 0.2% for total knee arthroplasty; p < 0.05 for each). The overall in-hospital complication and mortality rates of patients at least eighty years of age were significantly higher than those of patients sixty-five to seventy-nine years of age (p < 0.001 for both).CONCLUSIONS: During the previous decade, the rates of elective major orthopaedic surgical procedures in patients at least eighty years of age increased in the U.S. The in-hospital mortality rates decreased, whereas the overall in-hospital complication rates remained stable or increased. The overall event rates were low, and these elective procedures could be offered to very elderly patients.LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Concepts: Mortality rate, Demography, Life expectancy, Hip replacement, Orthopedic surgery, Joint replacement, Knee replacement, John Charnley

3

The diagnosis of hip pain after total hip replacement (THR) represents a highly challenging question that is of increasing concern to orthopedic surgeons. This retrospective study assesses bone scintigraphy with Hybrid SPECT/CT for the diagnosis of painful THR in a selected cohort of patients.

Concepts: Hip replacement, Hip, Pelvis, Orthopedic surgery, Joint replacement, John Charnley

2

Acetabular revision arthroplasty with major bone loss is one of the most difficult operations in orthopedic surgery. The goal of the study was to evaluate midterm clinical results of the use of morselized allografts with cemented cage support in revision total hip replacement.

Concepts: Bone, Bone fracture, Hip replacement, Hip, Pelvis, Orthopedic surgery, Joint replacement, John Charnley

2

The decision to drive after orthopaedic injury or surgery is fraught with legal and safety issues. Although driving is an important part of most patients' lives, there are no well-established guidelines for determining when it is safe to drive after injury or treatment. Typically, impairment in driving ability is measured by changes in the time needed to perform an emergency stop. Braking function returns to normal 4 weeks after knee arthroscopy, 9 weeks after surgical management of ankle fracture, and 6 weeks after the initiation of weight bearing following major lower extremity fracture. Patients may safely drive 4 to 6 weeks after right total hip arthroplasty or total knee arthroplasty. Patients should not drive with a cast or brace on the right leg. Upper extremity immobilization may cause significant impairment if the elbow is immobilized; however, simple forearm casts may be permissible.

Concepts: Hip replacement, Orthopedic surgery, Joint replacement, Joints, Knee replacement, Arthroscopy, Human leg, John Charnley

2

Various systems of computer-assisted orthopaedic surgery (CAOS) in total hip arthroplasty (THA) were reviewed. The first clinically applied system was an active robotic system (ROBODOC), which performed femoral implant cavity preparation as programmed preoperatively. Several reports on cementless THA with ROBODOC showed better stem alignment and less variance in limb-length inequality on radiographic evaluation, less incidence of pulmonary embolic events on transesophageal cardioechogram, and less stress shielding on the dual energy X-ray absorptiometry analysis than conventional manual methods. On the other hand, some studies raise issues with active systems, including a steep learning curve, muscle and nerve damage, and technical complications, such as a procedure stop due to a bone motion during cutting, requiring re-registration and registration failure. Semi-active robotic systems, such as Acrobot and Rio, were developed for ease of surgeon acceptance. The drill bit at the tip of the robotic arm is moved by a surgeon’s hand, but it does not move outside of a milling path boundary, which is defined according to three-dimensional (3D) image-based preoperative planning. However, there are still few reports on THA with these semi-active systems. Thanks to the advancements in 3D sensor technology, navigation systems were developed. Navigation is a passive system, which does not perform any actions on patients. It only provides information and guidance to the surgeon who still uses conventional tools to perform the surgery. There are three types of navigation: computed tomography (CT)-based navigation, imageless navigation, and fluoro-navigation. CT-based navigation is the most accurate, but the preoperative planning on CT images takes time that increases cost and radiation exposure. Imageless navigation does not use CT images, but its accuracy depends on the technique of landmark pointing, and it does not take into account the individual uniqueness of the anatomy. Fluoroscopic navigation is good for trauma and spine surgeries, but its benefits are limited in the hip and knee reconstruction surgeries. Several studies have shown that the cup alignment with navigation is more precise than that of the conventional mechanical instruments, and that it is useful for optimizing limb length, range of motion, and stability. Recently, patient specific templates, based on CT images, have attracted attention and some early reports on cup placement, and resurfacing showed improved accuracy of the procedures. These various CAOS systems have pros and cons. Nonetheless, CAOS is a useful tool to help surgeons perform accurately what surgeons want to do in order to better achieve their clinical objectives. Thus, it is important that the surgeon fully understands what he or she should be trying to achieve in THA for each patient.

Concepts: Hospital, Surgery, Hip replacement, Hip, Orthopedic surgery, Joint replacement, Surgeon, John Charnley

1

Femoral fracture in the setting of a hip arthroplasty is an increasingly common complication encountered in the emergency department (ED). Diagnosis and management of periprosthetic fractures are complicated, and orthopedic surgeons rely on imaging findings to guide the appropriate management approach to the injury. Delay in identification and appropriate definitive management of periprosthetic fractures is associated with high morbidity and mortality. At present, the Vancouver classification system for periprosthetic hip fractures is the most common classification system used by orthopedic surgeons. It relies on three radiographic criteria-fracture location, prosthesis stability, and quality of the femoral bone stock-to characterize these fractures and to help guide management decisions. Familiarly with the Vancouver classification system allows radiologists to both recognize and communicate the most clinically relevant imaging findings to the treating orthopedic surgeon. This article reviews the imaging workup for hip pain in patients with a femoral prosthesis, risk factors for periprosthetic fracture, and the expected normal appearance of the most commonly encountered types of femoral prostheses. Fracture terminology and the Vancouver classification system are reviewed in a simplified algorithm with emphasis on the most common patterns of periprosthetic fractures, the radiologic determinants of prosthesis stability and bone quality, and the management implications of these imaging findings. Finally, multiple instructive clinical cases are used to demonstrate critical application of the classification system and to highlight the clinical implications of the imaging findings. (©)RSNA, 2017.

Concepts: Bone, Bone fracture, Hip fracture, Hip replacement, Orthopedic surgery, Joint replacement, Distraction osteogenesis, John Charnley