Compared with total knee arthroplasty, unicondylar knee replacement has the advantage of preserving the knee tissue structure and motor function to the greatest extent. Pre-clinical in-vitro test is an important tool to evaluate the safety and effectiveness of unicondylar knee prostheses, and it is also a key focus of the product registration process. Through collection, comparison, and analysis of current regulations, technical standards, guidelines, and related research literature, this paper expounds on the relevant research methods for the pre-clinical in-vitrotesting of unicondylar knee prostheses. At the same time, in conjunction with current evaluation requirements and experience, the study discusses the focus of pre-clinical performance research for unicondylar knee prostheses during the registration process to clarify the performance evaluation requirements of this product category. This aims to provide a reference for the pre-clinical performance research of unicondylar knee prostheses and to standardize industry testing standards.
Knee Prosthesis ; Arthroplasty, Replacement, Knee ; Humans ; Prosthesis Design ; Materials Testing

In recent years, the field of heart valve interventional treatment has developed rapidly, and various new technologies have been continuously applied. The study provides a comprehensive review and analysis of the research progress and challenges related to interventional treatment products for the aortic valve, pulmonary valve, mitral valve, and tricuspid valve both domestically and internationally. The study also summarizes the status of heart valve interventional devices entering Special Review of Innovative Medical Device of National Medical Products Administration (NMPA). The results show that the field of valve interventional treatment is developing rapidly, but there is still room for improvement in terms of valve durability, operational suitability, and complication reduction. Lastly, the study looks forward to the future development trend of new technologies for heart valve interventional therapy, and puts forward suggestions for the promotion and application of new technologies of valve interventional therapy from the perspective of supervision.
Humans ; Heart Valve Prosthesis ; Heart Valves/surgery* ; Heart Valve Diseases ; Heart Valve Prosthesis Implantation/instrumentation*

The wrist joint is a highly mobile functional joint. Wrist conditions including traumatic and degenerative arthritis, rheumatoid arthritis, and giant cell tumors of the distal radius, cause significant pain and mobility impairment. In joint surgery, the decision to use joint prostheses to reconstruct joint function is greatly influenced by the characteristics of the prosthesis (Mok et al., 2016). However, traditional implants have limitations such as shape mismatch, inadequate implant-bone interface strength which causes loosening, and poor bone ingrowth (Zhang et al., 2014).
Humans ; Joint Prosthesis ; Wrist Joint/surgery* ; Prosthesis Design ; Arthroplasty, Replacement ; Arthritis, Rheumatoid/surgery*

Objective:To compare the preoperative presentation, intraoperative findings, and postoperative outcomes between middle ear cholesteatoma with tympanosclerosis （MECwTS） and middle ear cholesteatoma without tympanosclerosis （MECw/oTS）, thereby investigating the clinical characteristics of MECwTS. Methods:A retrospective analysis was conducted on the clinical data of 120 patients with middle ear cholesteatoma. Patients were divided into two groups based on the presence or absence of concomitant tympanosclerosis: the MECwTS group （n=49） and the MECw/oTS group （n=71）. All patients underwent preoperative evaluations including temporal bone CT, otoscopic examination, pure-tone audiometry, tympanometry, and assessment using the Zurich Chronic Middle Ear Inventory （ZCMEI-21） quality of life scale. All patients underwent canal wall down mastoidectomy with tympanoplasty. Concurrent ossicular chain reconstruction was performed: partial ossicular replacement prosthesis （PORP） in 83 cases and total ossicular replacement prosthesis （TORP） in 37 cases. Intraoperative disease severity was assessed using the Cholesteatoma Comprehensive Score Scale （CCSS）. Postoperative follow-up lasted at least one year and included pure-tone audiometry, otoscopic examination, and the ZCMEI-21 scale administered at ≥1 year post-surgery. Preoperative and postoperative air-bone gap （ABG） and ZCMEI-21 scores were compared between the MECwTS and MECw/oTS groups. Additionally, surgical efficacy was defined as a postoperative ABG ≤20 dB; the hearing improvement efficacy of PORP versus TORP was compared based on this criterion. Results: ①Preoperative ABG showed no significant difference between the MECw/oTS and MECwTS groups（P>0.05）. Postoperative ABG was （18.65±10.21） dB in the MECw/oTS group versus （22.55±9.53） dB in the MECwTS group, demonstrating a statistically significant intergroup difference （P<0.05）. ②Intraoperative CCSS scores were significantly higher in the MECwTS group （8.04±2.18） compared to the MECw/oTS group （5.93±1.44） （P<0.05）. ③Preoperative ZCMEI-21 scores showed no significant difference between groups （P>0.05）. Postoperative ZCMEI-21 scores were （22.24±8.11） in the MECw/oTS group versus （27.02±7.21） in the MECwTS group, indicating a statistically significant difference （P<0.05）. ④Postoperative ABG ≤20 dB was achieved in 54 patients （65.06%, 54/83） in the PORP group and 16 patients （43.24%, 16/37） in the TORP group. This difference in efficacy rates was statistically significant （P<0.05）. The overall efficacy rate for ossiculoplasty was 58.33% （70/120）. Conclusion: Patients with MECwTS exhibit more severe middle ear and mastoid pathology compared to those with MECw/oTS, resulting in poorer postoperative hearing levels and quality of life outcomes. Both PORP and TORP implantation can improve postoperative hearing to some extent; however, PORP appears to offer superior hearing improvement efficacy compared to TORP.
Humans ; Cholesteatoma, Middle Ear/complications* ; Retrospective Studies ; Tympanoplasty ; Myringosclerosis/surgery* ; Female ; Male ; Adult ; Middle Aged ; Ossicular Replacement ; Ossicular Prosthesis ; Young Adult ; Ear, Middle ; Treatment Outcome ; Mastoidectomy ; Audiometry, Pure-Tone ; Adolescent ; Quality of Life

The reconstruction of the temporomandibular joint presents a multifaceted clinical challenge in the realm of head and neck surgery, underscored by its relatively infrequent occurrence and the lack of comprehensive clinical guidelines. This review aims to elucidate the available approaches for TMJ reconstruction, with a particular emphasis on recent groundbreaking advancements. The current spectrum of TMJ reconstruction integrates diverse surgical techniques, such as costochondral grafting, coronoid process grafting, revascularized fibula transfer, transport distraction osteogenesis, and alloplastic TMJ replacement. Despite the available options, a singular, universally accepted 'gold standard' for reconstructive techniques or materials remains elusive in this field. Our review comprehensively summarizes the current available methods of TMJ reconstruction, focusing on both autologous and alloplastic prostheses. It delves into the differences of each surgical technique and outlines the implications of recent technological advances, such as 3D printing, which hold the promise of enhancing surgical precision and patient outcomes. This evolutionary progress aims not only to improve the immediate results of reconstruction but also to ensure the long-term health and functionality of the TMJ, thereby improving the quality of life for patients with end-stage TMJ disorders.
Humans ; Temporomandibular Joint/surgery* ; Temporomandibular Joint Disorders/surgery* ; Transplantation, Autologous ; Arthroplasty, Replacement/methods* ; Joint Prosthesis ; Plastic Surgery Procedures/methods*

Immediate implant-supported fixed restoration in edentulous jaws demonstrates a success rate comparable to that of conventional implant restoration. However, this approach still presents a certain degree of technique sensitivity. In the field of immediate implant-supported fixed restoration in dentistry, a repeatable and stable jaw relation is the prerequisite for the design and fabrication of prostheses. It also reduces chairside denture placement and occlusal adjustment time and lowers the risk of occlusion-related complications. For patients with terminal dentition, the precise transfer of jaw relation following full-arch implantation serves as the fundamental basis for implant-supported occlusal reconstruction and functional restoration. This process is also a key research focus and challenge in the area of implant-supported occlusal rehabilitation. This review summarizes the procedures and methods for determining and transferring jaw relation in immediate implant-supported fixed restoration. It aims to serve as a basis for clinical decision making in implant-supported fixed restorations for terminal dentition patients.
Humans ; Dental Prosthesis, Implant-Supported ; Clinical Decision-Making ; Immediate Dental Implant Loading ; Jaw, Edentulous/surgery*

Prosthesis loosening is the leading cause of postoperative revision in unicompartmental knee arthroplasty (UKA). The deviation of medial and lateral translational installation of the prosthesis during surgery is a common clinical phenomenon and an important factor in increasing the risk of prosthesis loosening. This study established a UKA finite element model and a bone-prosthesis fixation interface micromotion prediction model. The predicted medial contact force and joint motion of the knee joint from a patient-specific lower extremity musculoskeletal multibody dynamics model of UKA were used as boundary conditions. The effects of 9 femoral component medial and lateral translational installation deviations on the Von Mises stress of the proximal tibia, the contact stress, and the micro-motion of the bone prosthesis fixation interface were quantitatively studied. It was found that compared with the neutral position (a/A of 0.492), the lateral translational deviation of the femoral component significantly increased the tibial Von Mises stress and the bone-prosthesis fixation interface contact stress. The maximum Von Mises stress and the maximum contact stress of the fixation interface increased by 14.08% and 143.15%, respectively, when a/A was 0.361. The medial translational deviation of the femoral component significantly increased the bone-prosthesis fixation interface micro-motion. The maximum value of micromotion under the conditions of femoral neutral and medial translation deviation was in the range of 20-50 μm, which is suitable for osseointegration. Therefore, based on considerations such as the micromotion range suitable for osseointegration reported in the literature, the risk of reducing prosthesis loosening, and factors that may induce pain, it is recommended that clinicians control the mounting position of the femoral component during surgery within the safe range of 0-4 mm medial translation deviation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Finite Element Analysis ; Biomechanical Phenomena ; Knee Prosthesis ; Tibia/surgery* ; Femur/surgery* ; Stress, Mechanical ; Prosthesis Failure ; Knee Joint/surgery* ; Prosthesis Design

The orientation of the acetabular cup in hip joint anteroposterior radiograph is a key factor in evaluating the postoperative outcomes of total hip arthroplasty (THA). Currently, measurement of the acetabular cup anteversion angle primarily relies on manual drawing of auxiliary lines by orthopedic surgeons and calculations using scientific calculators. This study proposes an automated computer-aided measurement method for the acetabular cup anteversion angle based on hip joint anteroposterior radiograph. The proposed method segments hip prosthesis images using an improved Otsu algorithm, identifies feature points at the acetabular cup opening by combining circle-fitting theory and the cup's geometric characteristics, and fits an ellipse to the cup opening to calculate the anteversion angle. A total of 104 hip joint anteroposterior radiographs, including 71 right-sided and 81 left-sided prostheses, were analyzed. Two orthopedic surgeons independently measured the postoperative anteversion angles, and the results were compared with computer-generated measurements for correlation analysis. Spearman and Pearson correlation analyses demonstrated significant correlations between the proposed method and manual measurements for both the right group ( r = 0.795, P < 0.01) and the left group ( r = 0.859, P < 0.01). This method provides a reliable reference for orthopedic surgeons to assess postoperative prognosis.
Humans ; Acetabulum/anatomy & histology* ; Arthroplasty, Replacement, Hip/methods* ; Algorithms ; Hip Prosthesis ; Hip Joint/diagnostic imaging* ; Radiography ; Image Processing, Computer-Assisted/methods*

Although metal blocks have been widely used for reconstructing uncontained tibial bone defects, the influence of their elastic modulus on the stability of tibial prosthesis fixation remains unclear. Based on this, a finite element model incorporating constrained condylar knee (CCK) prosthesis, tibia, and metal block was established. Considering the influence of the post-restraint structure of the prosthesis, the effects of variations in the elastic modulus of the block on the von Mises stress distribution in the tibia and the block, as well as on the micromotion at the bone-prosthesis fixation interface, were investigated. Results demonstrated that collision between the insert post and femoral prosthesis during tibial internal rotation increased tibial von Mises stress, significantly influencing the prediction of block elastic modulus variation. A decrease in the elastic modulus of the metal block resulted in increased von Mises stress in the proximal tibia, significantly reduced von Mises stress in the distal tibia, decreased von Mises stress of the block, and increased micromotion at the bone-prosthesis fixation interface. When the elastic modulus of the metal block fell below that of bone cement, inadequate block support substantially increased the risk of stress shielding in the distal tibia and fixation interface loosening. Therefore, this study recommends that biomechanical investigations of CCK prostheses must consider the post-constraint effect, and the elastic modulus of metal blocks for bone reconstruction should not be lower than 3 600 MPa.
Knee Prosthesis ; Humans ; Finite Element Analysis ; Tibia/surgery* ; Elastic Modulus ; Arthroplasty, Replacement, Knee/methods* ; Stress, Mechanical ; Metals ; Prosthesis Design ; Knee Joint/surgery* ; Biomechanical Phenomena

Stent migration is one of the common complications following transcatheter valve implantation. This study aims to design a "drum-shaped" balloon-expandable aortic valve stent to address this issue and conduct a mechanical analysis. The implantation process of the stent was evaluated using a method that combines numerical simulation and in vitro experiments. Furthermore, the fatigue process of the stent under pulsatile cyclic loading was simulated, and its fatigue performance was assessed using a Goodman diagram. The process of the stent migrating toward the left ventricular side was simulated, and the force-displacement curve of the stent was extracted to evaluate its anti- migration performance. The results showed that all five stent models could be crimped into a 14F sheath and enabled uniform expansion of the native valve leaflets. The stress in each stent was below the ultimate stress, so no fatigue fracture occurred. As the cell height ratio decreased, the contact area fraction between the stent and the aortic root gradually decreased. However, the mean contact force and the maximum anti-migration force first decreased and then increased. Specifically, model S5 had the smallest contact area fraction but the largest mean contact force and maximum anti-migration force, reaching approximately 0.16 MPa and 10.73 N, respectively. The designed stent achieves a "drum-shaped" change after expansion and has good anti-migration performance.
Stents ; Prosthesis Design ; Heart Valve Prosthesis ; Humans ; Aortic Valve/surgery* ; Stress, Mechanical ; Transcatheter Aortic Valve Replacement/instrumentation*