The choice of friction interface has always been a controversial topic in hip arthroplasty. Although the metal-on-metal (MoM) interface has gradually faded out of our vision, its revision is a clinical difficulty. Adverse reactions to metal debris (ARMD) is the most common indication for MoM hip arthroplasty revision, and the clinical results of hip arthroplasty due to ARMD are not satisfactory. At present, the indications and suggestions for revision of ARMD are not uniform. In this article, the clinical diagnosis, indications of revision, risk factors of prognosis, intraoperative suggestions and reasons for revision of ARMD were summarized. This article briefly introduces the diagnosis and treatment strategies and precautions of hip arthroplasty due to ARMD, in order to provide reference for such patients in clinical practice.
Arthroplasty, Replacement, Hip/adverse effects* ; Hip Prosthesis/adverse effects* ; Humans ; Metal-on-Metal Joint Prostheses/adverse effects* ; Prosthesis Design ; Prosthesis Failure ; Reoperation

Based on the introduction of multi-agent and individual artificial hip joints, this paper reports a multi-agent design system for individual artificial hip joints. Three agents are defined, the first is to optimize the diameter of hip joint, the second for FEM, the third for simulation between the prosthesis and acetabulum cup. The paper lays emphasis on the second agent.
Acetabulum ; Hip Joint ; Hip Prosthesis ; Humans ; Prosthesis Design

PURPOSE: Understanding elbow biomechanics is necessary to understand the pathophysiologic mechanism of elbow injury and to provide a scientific basis for clinical practice. This article provides a summary of key concepts that are relevant to understanding common elbow injuries and their management. MATERIALS AND METHODS: The biomechanics of the elbow joint can be divided into kinematics, stability and force transmission through the elbow joint. Active and passive stabilizers include bony articular geometry; soft tissues provide joint stability, compression force and motion. RESULTS AND CONCLUSION: Knowledge of elbow biomechanics will help (i) advance surgical procedures and trauma management, (ii) develop new elbow prostheses and (iii) stimulate future research.
Biomechanics ; Elbow ; Elbow Joint ; Elbow Prosthesis ; Joints

Because of increases in degenerative diseases and trauma of the hip joint, diverse treatment modalities have been developed. Because of this increase in demand in the field of hip joint medicine, the need for scientific studies in orthopaedics have been considered to be more important. In fact, currently, total hip arthroplasty is the most commonly performed reconstructive hip procedure. Total hip arthroplasty evolved as a result of many improvements in the design of a femoral head prosthesis, the availability of suitable component materials and manufacturing techniques, a better understanding of hip mechanics, and the need for resurfacing the acetabulum. An awareness of the history of hip arthroplasty is necessary to appreciate not only its current status, but also its future. This article discusses the history of and current trends in hip arthroplasty including implant design, materials, and the renewed interest in resurfacing procedures, minimally invasive techniques and robotic surgery.
Acetabulum ; Arthroplasty ; Hip ; Hip Joint ; Hip Prosthesis ; Mechanics

OBJECTIVETo investigate clinical characteristics and pathological changes of tissue surrounding prosthesis after hip and knee arthroplasty.

METHODSA total of 67 patients receiving hip and knee arthroplasty were included in the study and pathological changes of the revision specimens were evaluated by microscopic examination.

RESULTSOf 67 patients, there were 25 males and 42 females (ratio of 0.6) with a mean age of 64 years. There were 42 cases of revision hip prosthesis and 25 cases of knee prosthesis. The primary causes for the revision varied, including 20 cases of infection (29.9%, within 3 months in 9 cases,3 to 24 months in 3 cases and over 24 months in 8 cases), 14 cases of pain (20.9%), 13 cases of loosening of the prosthesis (19:4%), 9 cases of joint stiffness (13.4%), 8 cases of prosthetic dislocation (11.9%), and 3 cases of prosthesis fracture (4.5%). Pathological findings in the tissue surrounding the prostheses included debris reaction, histiocytes, acute inflammatory, chronic non-specific inflammation, pigmented villonodular synovitis (PVNS), "pseudomembranous", calcification, necrosis, sequestrum, etc. These histological changes were frequently admixed.

CONCLUSIONSVarious reasons may lead to hip and knee revision arthroplasty. The main pathological findings include infection, debris granulomas, chronic non-specific inflammatory changes, PVNS. The surgical pathology of the prosthesis provids guidances for clinical treatment and basic research.

Arthroplasty, Replacement, Hip ; Arthroplasty, Replacement, Knee ; Female ; Hip Joint ; pathology ; Humans ; Knee Joint ; pathology ; Knee Prosthesis ; Male ; Middle Aged ; Reoperation ; Synovitis, Pigmented Villonodular ; pathology

The assistant artificial hip joint (AAHJ) is a new impermanent hip support implanted in the body. It is used for treatment of ischemic necrosis of the femoral head at the early stage. It reserves the natural femoral head, increases its containment and decreases its load, thus makes the recovery of the necrosed femoral head. The AAHJ's moving axis center is the same as that of the femoral head. Therefore, the moving range of the hip joint is very close to the normal postoperatively. The patient can walk with loading in 3 weeks after the surgical operation, and can regain his (or her) daily work and life in 2 to 3 months of the operation. The AAHJ's structure is simple and the price is cheap.
Arthroplasty, Replacement, Hip ; instrumentation ; Femur Head Necrosis ; surgery ; Hip Joint ; surgery ; Hip Prosthesis ; Humans ; Prosthesis Design ; Recovery of Function ; Treatment Outcome

The rotation center of traditional hip disarticulation prosthesis is often placed in the front and lower part of the socket, which is asymmetric with the rotation center of the healthy hip joint, resulting in poor symmetry between the prosthesis movement and the healthy lower limb movement. Besides, most of the prosthesis are passive joints, which need to rely on the amputee's compensatory hip lifting movement to realize the prosthesis movement, and the same walking movement needs to consume 2-3 times of energy compared with normal people. This paper presents a dynamic hip disarticulation prosthesis (HDPs) based on remote center of mechanism (RCM). Using the double parallelogram design method, taking the minimum size of the mechanism as the objective, the genetic algorithm was used to optimize the size, and the rotation center of the prosthesis was symmetrical with the rotation center of the healthy lower limb. By analyzing the relationship between the torque and angle of hip joint in the process of human walking, the control system mirrored the motion parameters of the lower on the healthy side, and used the parallel drive system to provide assistance for the prosthesis. Based on the established virtual prototype simulation platform of solid works and Adams, the motion simulation of hip disarticulation prosthesis was carried out and the change curve was obtained. Through quantitative comparison with healthy lower limb and traditional prosthesis, the scientificity of the design scheme was analyzed. The results show that the design can achieve the desired effect, and the design scheme is feasible.
Arthroplasty, Replacement, Hip ; Artificial Limbs ; Biomechanical Phenomena ; Hip Joint ; Hip Prosthesis ; Humans ; Prosthesis Design ; Range of Motion, Articular ; Walking

An evaluation of the acetabular cartilage was performed grossly and histologically in a patient who had a bipolar hemiarthroploasty, which had served satisfactorily for 2 years until the femoral prosthetic head had been separated from the acetabular assembly due to creep deformation of the inner bearing polyethylene cup. This study indicates that the double-bearing bipolar prosthesis dose not necessarily have an advantage over the classical single-piece prosthesis in the prevention of acetabular cartilage wear.
Acetabulum/abnormalities* ; Cartilage, Articular/abnormalities* ; Hip Joint/abnormalities ; Hip Prosthesis* ; Human ; Male ; Middle Age ; Postoperative Complications/etiology* ; Prosthesis Failure

A novel method for the design of hip joint prostheses based on X-ray films is introduced. Only arcs and straight-lines form figures of hip joint prostheses. Because geometrical tolerances of manufacturing hip joint prostheses matching section are usually not strict, hip joint prostheses can be manufactured without CNC machine tool. Three hip joint prostheses for three different femurs were designed through a program which was developed by the present authors. Approximate marrow cavities of these femurs were simulated according to a standard database about femur. These models of femur marrow cavities were used to verify the hip joint prostheses designed. These hip joint prostheses designed were manufactured and implanted into femurs respectively. Experimental results indicate that the novel method for the design of hip joint prostheses is practicable.
Computer-Aided Design ; Hip Joint ; diagnostic imaging ; Hip Prosthesis ; Humans ; Prosthesis Design ; methods ; Tomography, X-Ray Computed

This paper is aimed to focus on the joint prosthesis failure event, to collect the statistic data about the failure of artificial joints issued by authoritative organizations at home and aboard, and to compare the functions of different types of the artificial joints. We generalized and compared current study analyzing the failure reason and type of joint prosthesis, and categorized the failure events according to the failure occurring time, i. e. short-term, medium-term and long-term. This paper could be helpful for improving and summarizing of artificial joint replacement surgery, and could put forward the requirements for the future artificial joints.
Arthroplasty, Replacement ; adverse effects ; statistics & numerical data ; Arthroplasty, Replacement, Hip ; adverse effects ; statistics & numerical data ; Arthroplasty, Replacement, Knee ; adverse effects ; statistics & numerical data ; Humans ; Joint Prosthesis ; Prosthesis Failure ; etiology