OBJECTIVE: The aim of this study was to determine the effect of transcutaneous electrical nerve stimulation (TENS) on pain, functionality, quality of life, and analgesic consumption in patients undergoing TKR.
METHODS: A single center, randomized controlled trial.
METHODS: A total of 52 participants were randomly assigned to the intervention (n = 26) and control (n = 26) groups. The intervention group was exposed to conventional TENS. Data were collected with a Patient Identification Form, the Visual Analogue Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Quality of Life Scale (SF-36), and the Analgesic Tracking Form.
RESULTS: VAS and WOMAC scores significantly decreased in the intervention group, over time, while they increased in the control group. SF-36 scores significantly increased in the intervention group over time. It was determined that analgesic consumption was significantly lower in the intervention group than in the control group.
CONCLUSIONS: TENS significantly reduced pain and increased functionality and quality of life. Our findings suggest that TENS may be an effective adjunctive analgesic therapy in patients receiving TKR; however, more testing is needed in larger and more heterogeneous populations.
CONCLUSIONS: Nurses can provide effective postoperative pain control in patients undergoing TKR, increase functionality, accelerate the healing process, and improve their quality of life by using TENS, a non-pharmacological treatment method, in the perioperative period.

Multifunctional materials have been described to meet the diverse requirements of implant materials for femoral components of uncemented total knee replacements. These materials aim to combine the high wear and corrosion resistance of oxide ceramics at the joint surfaces with the osteogenic potential of titanium alloys at the bone-implant interface. Our objective was to evaluate the biomechanical performance of hybrid material-based femoral components regarding mechanical stress within the implant during cementless implantation and stress shielding (evaluated by strain energy density) of the periprosthetic bone during two-legged squat motion using finite element modeling. The hybrid materials consisted of alumina-toughened zirconia (ATZ) ceramic joined with additively manufactured Ti-6Al-4V or Ti-35Nb-6Ta alloys. The titanium component was modeled with or without an open porous surface structure. Monolithic femoral components of ATZ ceramic or Co-28Cr-6Mo alloy were used as reference. The elasticity of the open porous surface structure was determined within experimental compression tests and was significantly higher for Ti-35Nb-6Ta compared to Ti-6Al-4V (5.2 ± 0.2 GPa vs. 8.8 ± 0.8 GPa, p < 0.001). During implantation, the maximum stress within the ATZ femoral component decreased from 1568.9 MPa (monolithic ATZ) to 367.6 MPa (Ti-6Al-4V/ATZ), 560.9 MPa (Ti-6Al-4V/ATZ with an open porous surface), 474.9 MPa (Ti-35Nb-6Ta/ATZ), and 648.4 MPa (Ti-35Nb-6Ta/ATZ with an open porous surface). The strain energy density increased at higher flexion angles for all models during the squat movement. At ∼90° knee flexion, the strain energy density in the anterior region of the distal femur increased by 25.7 % (Ti-6Al-4V/ATZ), 70.3 % (Ti-6Al-4V/ATZ with an open porous surface), 43.7 % (Ti-35Nb-6Ta/ATZ), and 82.5% (Ti-35Nb-6Ta/ATZ with an open porous surface) compared to monolithic ATZ. Thus, the hybrid material-based femoral component decreases the intraoperative fracture risk of the ATZ part and considerably reduces the risk of stress shielding of the periprosthetic bone.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most common and successful operations in the field of orthopaedics, with a steadily increasing number of patients. However, as the patient population becomes younger, expectations regarding the outcome of the surgery are also changing. In addition to pain reduction and improved mobility, the longevity of the implant and the recovery of (everyday) activity in general (return-to-activity, RtA) and sporting activity in particular (return-to-sports, RtS) are becoming increasingly important.
UNASSIGNED: RtS with a tendency towards low-impact sports seems generally possible but is highly dependent on the individual characteristics of the patient. Despite comprehensive studies on treatment with TKA, there are no systematic studies and reliable conclusions on the key factors that enable patients to return to sports after TKA. Any recommendation by the responsible surgeons remains dependent on their subjective experience due to the lack of standardized implementation of an RtA/RtS assessment and the necessary long-term follow-up observation under control of patient-related confounding factors.
UNASSIGNED: HINTERGRUND: Der Ersatz des Kniegelenks mittels einer Totalendoprothese (TKA) gilt als eine der häufigsten und erfolgreichsten Operationen des orthopädischen Fachgebietes mit stetig wachsenden Patientenzahlen. Einhergehend mit der zum Teil immer jünger werdenden Patientenklientel verändern sich jedoch auch die Erwartungshaltungen an das operative Outcome. Neben der Schmerzreduktion und der Verbesserung der Beweglichkeit sind auch die Langlebigkeit der Prothese und die Wiedererlangung von (Alltags‑)Aktivität im Allgemeinen („return-to-activity“ [RtA]) sowie von sportlicher Aktivität im Speziellen („return-to-sports“ [RtS]) von zunehmender Bedeutung.
UNASSIGNED: RtS mit Tendenz zu „Low-impact“-Sportarten scheint generell möglich, ist jedoch stark abhängig von den individuellen Eigenschaften des Patienten. Trotz umfangreicher Studienlage zur Versorgung mittels TKA, gibt es bisher keine systematischen Untersuchungen und aussagekräftigen Ergebnisse zu den entscheidenden Faktoren, die einen Wiedereintritt in eine sportliche Belastung nach TKA ermöglichen. Eine entsprechende Empfehlung seitens der behandelnden Chirurgen bleibt mangels standardisierter Implementierung eines RtA/RtS-Assessment sowie einer notwendigen Verlaufsbeobachtung im Langzeit-Follow-up unter Kontrolle der patientenbezogenen Störfaktoren, abhängig von deren subjektiven Erfahrungen.

UNASSIGNED: One of the most debated topics in modern total knee arthroplasty (TKA) is the impact of metal hypersensitivity (MH) as a potential cause of prosthesis failure. Implanting hypoallergenic prostheses to avoid potential problems in suspected cases of MH is one treatment option that can be used in such cases. However, their long-term clinical safety and efficacy are not well proven.
UNASSIGNED: All literature relevant to modern hypoallergenic implants were reviewed and summarized to provide a comprehensive synopsis. In addition, a detailed literature search was performed on PUBMED, MEDLINE, and Google Scholar to identify all the clinical studies reporting outcomes for hypoallergenic knee implants. Our search was confined to those studies published as full manuscripts in the English language from July 2018 to July 2023.
UNASSIGNED: To minimize the risk of MH, new implant variants have been developed which are either under clinical evaluation or in routine clinical use. These include conventional metal implants with protective coatings (mono- or multilayer) and metal-free implants. However, there is insufficient clinical data to confirm the rationale and effectiveness of using these \"hypoallergenic\" TKA implants.
UNASSIGNED: Published studies and arthroplasty registry data analyses indicate no significant differences between hypoallergenic and standard TKAs with overall good survival rates. In the future, further high-quality studies are needed to better understand the complexity of this subject.

BACKGROUND: In total knee arthroplasty (TKA), cementless fixation is initially weaker than cement fixation. This study aimed to examine whether filling the tibial peg holes with bone improves initial fixation strength in cementless TKA.
METHODS: This prospective, comparative study examined 88 joints in 66 patients randomized to the bone filling (48 joints) or conventional group (no bone filling; 40 joints). All patients underwent TKA with the NexGen® trabecular metal modular tibial component. In the bone filling group, resected cancellous bone was filled into the peg holes before insertion of the tibial component. We performed clinical and plain radiographic evaluations after the operation and measured bone mineral density (BMD) at five sites below the component at 1, 3, 6, and 12 months postoperatively.
RESULTS: Operative time and clinical evaluations were not significantly different. Plain radiography showed significant longitudinal thickening of the trabecula below the peg (P<0.05) and decreased occurrence of reactive lines (P=0.07) in the bone filling group compared with the conventional group. BMD was significantly higher in the bone filling group in the medial region below the peg at 1, 3, and 6 months and in the central region at 1 and 3 months (all P<0.05).
CONCLUSIONS: When using the NexGen trabecular metal modular tibial component, concurrent peg hole bone filling increases the initial component fixation strength. Possible effects on long-term stabilization warrant further study.

OBJECTIVE: It has been shown that total knee replacement improves functional capacity and physical activity; however, the influence of age remains unclear. The objective is evaluate the pre and postoperative physical activity measured with the Knee Society Score (KSS) score and the Tegner score.
METHODS: A retrospective cohort analysis was conducted on patients who underwent total knee replacement (TKR) between January 2016 and December 2019 at our institution. Demographic variables (age, sex, and body mass index), activities of daily living, age-adjusted Charlson Comorbidity Index, American Society of Anesthesiologists score, the Knee Society Score (KSS) in its clinical (KSSc) and functional (KSSf) subscales, the Tegner functional scale, activity variables from the 2011 KSS version, and pain assessment using the visual analog scale were collected. Differences in these variables were analyzed between two age groups: group A (between 65 and 79 years old) and group B (80 years or older).
RESULTS: A total of 450 patients were evaluated (group A=245, group B=167). Group A showed a Tegner improvement of 1.19 (95% CI: 1.06-1.31), whereas group B averaged 0.61 (95% CI: 0.43-0.80) (P<.001). Age >80 was an independent risk factor for less Tegner improvement. In KSSc, group A improved by 43 points (95% CI: 40.82-46.14), while group B showed a greater increase of 53 points (95% CI: 49.74-57.80). Adjusted for confounders, those>80 showed significantly higher KSSc improvement (12.8 points). For KSSf, group A improved by 33.91 points (95% CI: 31.07-36.75), and group B by 15.57 points (95% CI: 11.78-19.35). Adjusted for confounders, patients >80 had less improvement than those <80 (19 points).
CONCLUSIONS: Patients who underwent TKR experienced improvements in physical and functional activity parameters. While these improvements were seen in the entire population, they were most notable in patients younger than 80 years.

BACKGROUND: Knee arthritis is a destructive disorder that affects the knee joints and causes pain and reduced mobility. Drug treatments, weight loss, and exercise control the symptoms of the disease, but these methods only delay the disease process and eventually, knee joint replacement surgery will be needed. After surgery, with the help of a proper physiotherapy program, full recovery takes an average of 6-12 months. However, currently, there is no similar tool to facilitate this process in Iran.
OBJECTIVE: The purpose of this research is to design and develop the prototype of a rehabilitation system for patients after knee replacement surgery, which provides patients with information and appropriate physiotherapy programs.
METHODS: This study was development-applied and was done in three stages. In the first stage, the needs and content of education and therapeutic exercises were prepared in the form of a checklist, and then the necessity of each item was checked in the evaluation sessions. In the second stage, the prototype of the system was developed using Adobe XD software and based on the requirements approved from the previous stage. In the third stage, the usability of the program was analyzed from the point of view of experts using the exploratory evaluation method with Nielsen\'s 13 principles of usability.
RESULTS: At first, the system requirements were extracted and prepared in two checklists of content (51 exercises) and capabilities (60 items). Then after a survey of experts based on the Delphi technique, content information (43 exercises) and functional and non-functional requirements (53 items) were obtained. A survey of experts helped to finalize the information elements, categorize them, and prepare the final version of the checklists. Based on this, the system requirements were classified into 11 categories, and the training content was classified into 3 training periods. Finally, the design and development of the system was done. This system has admin, physician, and patient user interfaces. The result of usability showed that this system is efficient and there are only a few problems in the feature of helping users to detect and recover from errors.
CONCLUSIONS: It seems necessary to develop a system based on the principles of usability by therapists and rehabilitation specialists to train and monitor the remote rehabilitation process of patients after knee joint replacement at home. And the importance of involving stakeholders in the design and development of remote rehabilitation systems is not hidden from anyone. Kara system has all of the above.

BACKGROUND: The survival of total knee arthroplasty (TKA) in patients with poliomyelitis remains a debated topic due to the high recurrence of postoperative genu recurvatum. This study aims to report the long-term survival of TKA in patients with poliomyelitis, using data from the Italian Register of Prosthetic Implantology.
METHODS: A registry-based population study was conducted, utilizing data from the Emilia Romagna orthopedic arthroplasty implants registry (RIPO - Registro Implantologia Protesica Ortopedica). The cohort consisted of 71 patients with poliomyelitis-related arthritis who underwent TKA. The study assessed and analyzed demographic data, implant type, fixation method, insert type, and level of constraint. Additionally, variations in preoperative and postoperative both clinical and functional Knee Society Scores (KSS) were collected.
RESULTS: Eight implants required revision surgery (16%), and three patients died (6.1%), resulting in a 10-year survival rate of 86.6% and a 15-year survival rate of 53.9%. Aseptic loosening was the primary cause of revision, accounting for 37.5% of failures, followed by insert wear (25%). No statistically significant correlation was found between the level of constraint and implant survival (p=0.0887, log-rank). Both the clinical and functional KSS improved postoperatively.
CONCLUSIONS: TKA is a viable alternative to knee arthrodesis and, in properly selected patients, might represent the first-choice treatment for articular degeneration due to its high survivorship. Despite the complexity of these cases, TKA can effectively alleviate articular pain, instability, and angular deviation, thereby preserving knee functionality.

Background and Objectives: As a treatment modality for advanced knee osteoarthritis, total knee arthroplasty is well established and has been performed on many patients over time. To improve surgical outcomes, fixed-bearing implant insertion with robotic-assisted TKA has been introduced; however, the insertion of mobile-bearing (MB) implants with the same method is challenging. The aim of this study was to compare the short-term postoperative follow-up outcomes of MB implant insertion using a robotic-assisted TKA system and conventional TKA. Materials and Methods: We investigated functional improvement in the knees of 60 patients who underwent the insertion of MB implants using either robotic-assisted TKA or conventional TKA. Isokinetic muscular function, range of motion, the Western Ontario and McMaster Universities Osteoarthritis Index score, visual analog scale (VAS) score, and Knee Society Score (KSS) were measured 6 months after surgery. The statistical analysis of outcome measurements was performed using the Mann-Whitney U test and the Wilcoxon signed-rank test. Results: Some isokinetic muscular functions, as well as Knee Society Scores (pain and function) and VAS scores, were significantly higher in patients who underwent MB insertion with robotic-assisted TKA than in those who underwent conventional TKA. Conclusions: When an MB implant is inserted using a robotic-assisted TKA system, a better surgical outcome can be expected.

UNASSIGNED: Previous epidemiological studies have indicated an increased risk of neurovascular diseases in patients following total hip and knee replacements. However, definitive conclusions regarding the increased risk of stroke post-replacement remain elusive. Therefore, we conducted a two-sample Mendelian randomization study to investigate the causal relationship between total hip and knee replacements and stroke.
UNASSIGNED: We utilized summary data from publicly available genome-wide association studies (GWAS). Data concerning total hip replacements (THR, N = 319,037) and total knee replacements (TKR, N = 252,041) were sourced from the Genetics of Osteoarthritis (GO) Consortium. Stroke-related data were obtained from the International Stroke Genetics Consortium, encompassing any stroke (AS), any ischemic stroke (AIS), large vessel ischemic stroke (LV-IS), cardioembolic ischemic stroke (CE-IS), and small vessel ischemic stroke (SV-IS). Our primary causal inference method was the inverse variance weighted (IVW) approach, supplemented by weighted median and MR-Egger regression as secondary inference methods. We utilized the MR-PRESSO global test for outlier detection, Cochran\'s Q statistic to assess heterogeneity, and assessed the multiplicity and stability of our findings using p-values from MR-PRESSO and MR-Egger regressions, and the leave-one-out method, respectively.
UNASSIGNED: We identified significant genetic associations between THR and both AS (IVW p = 0.0001, OR = 1.08, 95% CI = 1.04-1.12) and AIS (IVW p = 0.0016, OR = 1.07, 95% CI = 1.03-1.12). Significant associations were also observed between TKR and AS (IVW p = 0.0002, OR = 1.08, 95% CI = 1.04-1.12), as well as AIS (IVW p = 0.0005, OR = 1.15, 95% CI = 1.06-1.24).
UNASSIGNED: Our findings genetically support an increased risk of stroke following total hip and knee replacements. However, further studies are necessary to elucidate the specific mechanisms underlying stroke episodes post-replacement.