Van Nes rotationplasty has gained popularity as a surgical treatment for malignant bone tumors without resorting to amputation. However, the nature of the surgery poses unique challenges in the rehabilitation management in order to optimize safety and functional mobility. We describe a case of a 6-year-old female with Ewing’s sarcoma of the right femur who underwent Van Nes Type BIIIA rotationplasty. This procedure involved a complete femoral resection, with the tibia and the foot rotated by 180 degrees and the lateral tibial plateau placed into the acetabulum that is expected to remodel to form a neo-hip joint. The patient was referred to rehabilitation medicine and was eventually admitted due to impairment in mobility secondary to the surgery. The goal was to achieve K-1 level of function. This case demonstrates that the rehabilitation management of a child with Type B-IIIA rotationplasty using a modified Van Nes prosthesis requires a comprehensive multidisciplinary approach.

Humans ; Transcatheter Aortic Valve Replacement ; Aortic Valve/surgery* ; Heart Valve Prosthesis Implantation ; Renal Dialysis ; Aortic Valve Stenosis/surgery* ; Treatment Outcome ; Heart Valve Prosthesis

Humans ; Transcatheter Aortic Valve Replacement ; Aortic Valve/surgery* ; Heart Valve Prosthesis Implantation ; Renal Dialysis ; Aortic Valve Stenosis/surgery* ; Treatment Outcome ; Heart Valve Prosthesis

BACKGROUND: Patellofemoral joint (PFJ) degeneration has traditionally been regarded as a contraindication to unicompartmental knee arthroplasty (UKA). More recently, some researchers have proposed that PFJ degeneration can be ignored in medial UKA, and others have proposed that this change should be reviewed in PFJ degenerative facets and severity. This study aimed to systematically evaluate the effect of PFJ degeneration on patient-reported outcome measures (PROMs) and revision rates after medial UKA. METHODS: Electronic databases (PubMed, Embase, Web of Science, etc.) were searched for studies assessing the influence of PFJ degeneration on medial UKA. A random-effects meta-analysis was conducted for the Oxford knee score (OKS), Knee society score (KSS), and revision rates and stratified by PFJ degenerative facets (medial/lateral/trochlear/unspecified), severe PFJ degeneration (bone exposed), and bearing type (mobile/fixed). Heterogeneity was assessed by the Cochran Q test statistic and chi-squared tests with the I-squared statistic. RESULTS: A total of 34 articles with 7007 knees (2267 with PFJ degeneration) were included (5762 mobile-bearing and 1145 fixed-bearing and 100 unspecified). Slight to moderate degenerative changes in the medial and trochlear facets did not decrease the OKS and KSS, and only lateral facets significantly decreased the OKS (mean difference [MD] = -2.18, P   <  0.01) and KSS (MD = -2.61, P   <  0.01). The severity degree of PFJ degeneration had no additional adverse effect on the OKS, KSS, or revision rates. For mobile-bearing UKA, only lateral PFJ degeneration significantly decreased the OKS (MD = -2.21, P  < 0.01) and KSS (MD = -2.44, P  < 0.01). For fixed-bearing UKA, no correlation was found between PROMs/revision rates and PFJ degeneration. CONCLUSION For medial mobile-bearing UKA, slight to moderate degenerative changes in the PFJ, except lateral facet, did not compromise PROMs or revision rates. For medial fixed-bearing UKA, although it might not be conclusive enough, PROMs or revision rates were not adversely affected by PFJ degeneration (regardless of the facet).
Humans ; Arthroplasty, Replacement, Knee ; Patellofemoral Joint/surgery* ; Treatment Outcome ; Osteoarthritis, Knee/surgery* ; Knee Prosthesis ; Bone Diseases ; Knee Joint/surgery* ; Retrospective Studies

Humans ; Arthroplasty, Replacement, Knee ; Follow-Up Studies ; Cohort Studies ; Treatment Outcome ; Minimally Invasive Surgical Procedures ; Knee Joint/surgery* ; Knee Prosthesis ; Osteoarthritis, Knee/surgery*

BACKGROUND: Total knee arthroplasty (TKA) can reduce severe joint pain and improve functional disability in hemophilia. However, the long-term outcomes have rarely been reported in China. Therefore, this study aimed to evaluate the long-term outcomes and complications of TKA in Chinese patients with hemophilic arthropathy. METHODS: We retrospectively reviewed patients with hemophilia who underwent TKA between 2003 and 2020, with at least 10 years of follow-up. The clinical results, patellar scores, patients' overall satisfaction ratings, and radiological findings were evaluated. Revision surgery for implants during the follow-up period was recorded. RESULTS: Twenty-six patients with 36 TKAs were successfully followed up for an average of 12.4 years. Their Hospital for Special Surgery Knee Score improved from an average of 45.8 to 85.9. The average flexion contracture statistically significantly decreased from 18.1° to 4.2°. The range of motion (ROM) improved from 60.6° to 84.8°. All the patients accepted patelloplasty, and the patients' patellar score improved from 7.8 preoperatively to 24.9 at the last follow-up. There was no statistically significant difference in clinical outcomes between the unilateral and bilateral procedures, except for a better ROM at follow-up in the unilateral group. Mild and enduring anterior knee pain was reported in seven knees (19%). The annual bleeding event was 2.7 times/year at the last follow-up. A total of 25 patients with 35 TKAs were satisfied with the procedure (97%). Revision surgery was performed in seven knees, with 10- and 15-year prosthesis survival rates of 85.8% and 75.7%, respectively. CONCLUSIONS TKA is an effective procedure for patients with end-stage hemophilic arthropathy, which relieves pain, improves knee functions, decreases flexion contracture, and provides a high rate of satisfaction after more than ten years of follow-up.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Hemophilia A/surgery* ; Follow-Up Studies ; Retrospective Studies ; Treatment Outcome ; Knee Joint/surgery* ; Range of Motion, Articular ; Arthritis/complications* ; Pain ; Contracture/surgery* ; Surgeons ; Knee Prosthesis

Humans ; Arthroplasty, Replacement, Knee/adverse effects* ; Surgical Wound Infection/etiology* ; Retrospective Studies ; Risk Factors ; Arthroplasty, Replacement, Hip/adverse effects* ; Prosthesis-Related Infections/etiology*

The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients' walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427-0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
Humans ; Arthroplasty, Replacement, Knee ; Knee Joint/surgery* ; Knee Prosthesis ; Gait ; Rotation

Znic (Zn) alloys with good cytocompatibility and suitable degradation rate have been a kind of biodegradable metal with great potential for clinical applications. This paper summarizes the biological role of degradable Zn alloy as bone implant materials, discusses the mechanical properties of different Zn alloys and their advantages and disadvantages as bone implant materials, and analyzes the influence of different processing strategies (such as alloying and additive manufacturing) on the mechanical properties of Zn alloys. This paper provides systematic design approaches for biodegradable Zn alloys as bone implant materials in terms of the material selection, product processing, structural topology optimization, and assesses their application prospects with a view to better serve the clinic.
Orthopedics ; Zinc ; Alloys ; Dental Materials ; Prostheses and Implants

OBJECTIVE: To compare the short-term effectiveness of "SkyWalker" robot-assisted total knee arthroplasty (TKA) and traditional TKA. METHODS: A clinical data of 54 patients (54 knees) with TKA who met the selection criteria between January 2022 and March 2022 was retrospectively analyzed. Among them, 27 cases underwent traditional TKA (traditional operation group) and 27 cases underwent "SkyWalker" robot-assisted TKA (robot-assisted operation group). There was no significant difference between the two groups ( P>0.05) in terms of gender, age, body mass index, osteoarthritis side, disease duration, and preoperative Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), visual analogue scale (VAS) score, hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and posterior proximal tibial angle (PPTA). The operative time, intraoperative bleeding volume, surgery-related complications, the KSS, WOMAC, and VAS scores before operation and at 6 months after operation, and Forgotten Joint Score (FJS) at 6 months after operation were recorded. X-ray films were taken to review the prosthesis position and measure HKA, LDFA, MPTA, and PPTA. The differences of the clinical and imaging indicators between before and after operation were calculated and statistically analyzed. RESULTS: The operations were completed successfully in both groups. There was no significant difference in the operative time and intraoperative bleeding volume between the two groups ( P>0.05). After operation, 1 case of incision nonunion and 1 case of heart failure occurred in the traditional operation group, while no surgery-related complications occurred in the robotic-assisted operation group. The incidences of surgical complications were 7.4% (2/27) in the traditional operation group and 0 (0/27) in the robotic-assisted operation group, with no significant difference ( P=0.491). Patients in both groups were followed up 6 months. KSS score, WOMAC score, VAS score, and ROM significantly improved in both groups at 6 months after operation when compared with preoperative ones ( P<0.05). There was no significant difference between the two groups ( P>0.05) in the differences between the pre- and post-operative values of the clinical indicators and FJS scores at 6 months after operation. X-ray films showed that the lower extremity force lines of the patients improved and the knee prostheses were in good position. Except for LDFA in the robot-assisted operation group, HKA, LDFA, MPTA, and PPTA significantly improved in both groups at 6 months after operation when compared with the preoperative ones ( P<0.05). There was no significant difference between the two groups in the differences between the pre- and post-operative values of the radiological indicators ( P>0.05). CONCLUSION The "SkyWalker" robot-assisted TKA is one of the effective methods for the treatment of knee osteoarthritis and had good short-term effectiveness. But the long-term effectiveness needs to be further studied.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Knee Joint/surgery* ; Knee Prosthesis ; Osteoarthritis, Knee/surgery* ; Retrospective Studies ; Robotics ; Treatment Outcome