Search Results (84)

Background/Objectives: The importance of resistance training for functional recovery in Total Knee Arthroplasty (TKA) patients has been emphasized. Therefore, this systematic review and meta-analysis was conducted to analyze its effects on pain, muscle strength, and function in patients with TKA. Methods: The following databases were used: PubMed, Web of Science, the Cochrane Library, and Embase. Randomized controlled trials that administered resistance training to patients undergoing TKA and measured pain, strength, and function were included. The risk of bias was assessed using the Cochrane Risk of Bias 2.0 tool. Effect sizes were calculated using Hedges’ g and are presented as Standardized Mean Differences (SMDs) with 95% Confidence Intervals (CIs). Subgroup analyses were conducted to determine the effect size based on the type and duration of the intervention. Results: The study selection process resulted in the inclusion of seven studies comprising a total of 439 participants. The bias assessment found that three studies had a low risk of bias and four had some concerns. Resistance training was effective in improving pain (SMD: 0.84, 95% CI: 0.11; 1.57, I²: 89.6%), muscle strength (SMD: 1.03, 95% CI: 0.29; 1.77, I²: 83.1%), self-reported function (SMD: 1.58, 95% CI: 0.15; 3.01, I²: 93.1%), and performance-based function (SMD: 0.74, 95% CI: 0.38; 1.11, I²: 68.9%). Subgroup analysis revealed significant differences in pain, strength, and performance-based function by comparison group, performance-based function by intervention duration, and self-reported function by intervention type. Conclusions: Resistance training improves pain, muscle strength, and function in TKA patients. Additionally, resistance training appears particularly effective when implemented as a standalone intervention or for durations under 12 weeks. These findings suggest that the design of resistance training protocols should be considered in clinical practice. Full article

Introduction: Total knee arthroplasty (TKA) is a treatment for knee pain, but some patients are not satisfied with their outcomes. Utilizing shared decision making (SDM) can lead to better decisions, satisfaction, and fewer regrets. However, healthcare professionals have little knowledge of risk factors for regret. The aim of this study is to evaluate decisional regret using the Decision Regret Scale (DRS) after primary TKA among patients who engaged in SDM. Method: A total of 118 patients who underwent TKA surgery between March 2020 and May 2022 participated in this study, and they were able to reflect on their outcomes. The primary outcome was decisional regret assessed using the DRS, and the secondary outcome was post-operative pain at a three-month follow-up, measured using the Lequesne Index. Result: The study found that 49% of the patients reported no regret, 25% reported mild regret, and 26% reported moderate-to-severe regret. There was a significant correlation between greater levels of decision regret and a higher three-month Lequesne Index. Post-operative pain and post-operative mobility status and the range of motion of the knee joint were also strongly correlated. Conclusion: The study found that more than half of the patients undergoing primary TKAs experienced regret even following SDM counseling. Regret levels were associated with higher post-operative pain and poorer mobility. This underscores the importance of informing patients about potential adverse effects of TKA to manage their expectations and reduce regret in future SDM interviews. Practice implications: This study incorporated patient perspectives through their direct engagement in the SDM process prior to surgery. Patients participated in the design of the SDM framework, which included educational pamphlets and structured interviews to assess their values and preferences. Their involvement ensured that the SDM procedure was tailored to patient-centered outcomes. Furthermore, the follow-up assessments were conducted with patients to evaluate decisional regret and post-operative outcomes, providing valuable insights into the effectiveness of the SDM process. By actively participating in the research through decision making and outcome reflection, the patients contributed to the understanding of factors influencing decisional regret after undergoing TKA. Full article

Background/Objectives: Periprosthetic joint infection (PJI) is a severe complication that follows arthroplasty and occurs in approximately 2% of all cases. One of several cornerstones of therapy is an optimized antibiotic regimen. Early administration of rifampicin—together with a combination of an antibiotic to which the specific microorganism is susceptible—accompanying a two-stage revision surgery, remained controversial due to the potential risk of emerging resistance. However, the exact time to start rifampicin treatment often remains unclear and might be crucial in the treatment regimen. Methods: In a retrospective study design, a total of 212 patients receiving a two-stage revision surgery after a diagnosis of PJI (60.8% THA, 39.2% TKA) received an individual rifampicin combination therapy after initial debridement and removal of all foreign material, starting rifampicin on the second day postoperatively. Results: At the time of spacer explantation, two patients had developed rifampicin resistance (0.9%). At follow-up (M = 55.4 ± 21.8 months) after reimplantation, three patients had developed rifampicin resistance (1.4%). Concerning the development of reinfection, in general, in the study group and the necessity for further treatment, a total of 25 patients showed signs of reinfection (11.8%). Conclusions: Only 0.9% after the first stage and 1.4% at follow-up after the second stage of all 212 patients with accompanying long-term rifampicin combination therapy developed a rifampicin resistance. Therefore, rifampicin administration could be started on the second postoperative day when sufficient concentrations of the accompanying antibiotics can be expected. Full article

Background: Total knee arthroplasty (TKA) is a widely performed procedure to alleviate pain and restore function in patients with advanced knee osteoarthritis. Two common implant designs are cruciate-retaining (CR) and posterior-stabilized (PS) knees. Despite extensive research, the superiority of one design over the other remains inconclusive. Methods: A prospective analysis was conducted on 123 patients who underwent total knee arthroplasty (TKA) between June 2022 and June 2023 at a university hospital. Demographic data, mobility, the use of walking aids, pre- and postoperative range of motion and leg axis as well as surgical and systemic complications were collected and compared between CR and PS-TKA. Results: The mean age of the patients was 67.94 ± 10.14 years and 65.9% were women. The time of operation was significantly different between PS- and CR-TKA (PS: 83.31 ± 25.65 min; CR: 95.26 ± 24.61 min; p = 0.011). The pre- to postoperative leg axis after six months was significantly different in both groups (PS: 7.06° ± 4.76°; CR: 6.25° ± 3.13°; p = 0.001). The range of motion (ROM) (PS: 105.19° ± 15.56°; CR: 93.29° ± 15.09°; p = 0.001) as well as the deficit after six months (PS: 23.56° ± 19.73°; CR: 37.57° ± 23.33°; p = 0.003) between patients with PS and CR-TKA were significantly different. Gender (male vs. female PS/CR) and age (<75 years vs. >75 years PS/CR) differences were shown for the ROM and flexion deficit after six months (p = 0.003; p = 0.005). For age, a significant difference was shown for the quality of life (mean ranks: <75 y: 47.96; >75 y: 31.03; p = 0.009) and WOMAC score (mean ranks: <75 y: 38.27; >75 y: 61.75; p = 0.001) after six months. Conclusions: This study shows the different outcomes for posterior-stabilized versus cruciate-retaining TKA with regard to time of surgery, range of motion, and flexion deficit after 6 months with PS-TKA yielding better results. The gender analyses revealed similar outcomes after six months between both arthroplasty groups, whereas the age analyses revealed significant differences. The standardized use of PS-TKA for the elderly is recommended. Full article

Bone marrow aspirate concentrate (BMAC) is an autologous regenerative therapy enriched with mesenchymal stem cells (MSCs) and bioactive growth factors, offering potential disease-modifying effects in knee osteoarthritis (OA). Compared to conventional intra-articular treatments, including hyaluronic acid (HA), platelet-rich plasma (PRP), and corticosteroids, BMAC promotes cartilage regeneration, modulates inflammation, and enhances subchondral bone remodeling. Clinical evidence suggests that BMAC provides short- to mid-term symptomatic relief and functional improvement, with some studies indicating a potential to delay total knee arthroplasty (TKA). However, findings remain inconsistent, and long-term efficacy compared to PRP or autologous conditioned serum (ACS) is yet to be firmly established. Variability in BMAC preparation methods, injection protocols (single vs. repeated administration, intra-articular vs. subchondral delivery), and patient selection criteria complicates its clinical application, highlighting the need for standardized guidelines. Additionally, economic feasibility and cost-effectiveness concerns limit its widespread adoption. This review synthesizes current clinical evidence, evaluates optimal administration strategies, and explores future directions for improving treatment standardization and patient-specific therapy. Future research should prioritize well-designed, multicenter randomized controlled trials (RCTs) with long-term follow-up to confirm the sustained efficacy and therapeutic potential of BMAC in OA management. Full article

Background and Objectives: Total knee arthroplasty (TKA) is one of the most common medical procedures worldwide. However, 10 to 20% of patients are still dissatisfied despite implants and surgical technique advancements. Recently, several medial-stabilized TKAs have been developed in attempts to replicate the native kinematics of the knee. The aim of this scoping review on medial-stabilized TKA inserts—medial congruent (MC) and medial pivot (MP)—is to focus on their clinical outcomes and the role of the posterior cruciate ligament (PCL), aiming to systematically map the existing research and highlight current knowledge gaps. Materials and Methods: A search of the PubMed, Embase and Cochrane databases was performed to identify relevant studies on the kinematics and outcomes of medial pivot (MP) or medial congruent (MC) inserts. The following Mesh terms were used in combination with the Boolean operators “AND” and “OR”: “total knee arthroplasty”, “total knee replacement”, “medial pivot”, “medial congruence”, “outcomes” and “kinematic”. Original studies reporting on clinical outcomes assessed with validated patient-reported scales, surgical techniques and reoperation rates for any reason with a minimum follow-up of 18 months were included. Results: A total of 39 articles met the inclusion criteria, accounting for 6143 total knee replacements. The overall reoperation-free survivorship rate was 98.4% (6047 out of 6143 knees) at a weighted average follow-up of 6.3 years (range 1.5–15.2 years, SD 0.7). Both MP and MC inserts demonstrated good outcomes, with no differences between groups. Few studies evaluated the role of the PCL in MP and MC inserts, with no differences in terms of clinical outcomes between retaining and sacrificing the PCL. Conclusions: MS-TKA demonstrated good outcomes in the literature independently of the specific design (medial pivot or medial congruent). Different possible biases may be present when evaluating the outcomes of these inserts, including different types of alignment and soft tissue balancing philosophies. Full article

Background: Although cemented total knee arthroplasty (TKA) is considered the standard fixation technique, the emerging trend toward cementless fixation has created the need for a detailed comparison. In a previous study, we reported the 5-year results comparing cementless and hybrid cemented TKAs using the same implant design. The purpose of this study was to assess the long-term follow-up at a minimum of 10 years. Methods: A retrospective analysis was performed on 120 TKAs (60 cementless, 60 hybrid cemented) conducted between 2003 and 2007 using the e.motion posterior cruciate-retaining knee prosthesis with a floating-platform mobile polyethylene bearing (Aesculap, Tuttlingen, Germany). Demographic and clinical data were collected; radiographic follow-up was performed with attention to signs of loosening, while complications and revision surgery were assessed using competing risk analysis. Operative time was recorded as an indicator of surgical efficiency. Results: At 10 years, 59 TKAs (54 patients) were available for long-term follow-up. Both fixation groups demonstrated significant improvement in Knee Society Scores (KSSs) compared to preoperative values (p < 0.001). However, there was no significant difference in KSSs between the two groups at 10 years follow-up (p = 0.480). The 10-year cumulative incidence of revision was 8.4% in both groups (p = 0.721), and that of aseptic loosening was identical at 3.4% (p = 0.967). Although radiolucent lines were noted in three tibial components of the cementless group, the difference was not statistically significant (p = 0.075). Notably, the cementless group demonstrated a significantly shorter operative time with a mean difference of 10 min (p = 0.017). Conclusions: At a minimum follow-up of 10 years, there were no significant differences between the hybrid cemented and cementless groups in revision rates, cumulative incidences, clinical scores, or radiological signs of loosening, confirming the long-term effectiveness of both fixation methods in clinical practice. Full article

The development of an instrumented patellar prosthesis, able to measure the contact forces at the patellofemoral joint, can significantly aid in investigating the causes of total knee arthroplasty failures due to patellar complications. This study focuses on developing and validating an instrumented patellar prosthesis to measure contact forces in the patellofemoral joint. A piezoresistive force sensor was characterized and integrated into a conditioning circuit, with the aim of its implementation in the prosthesis. To measure medial and lateral forces independently, the sensors were trimmed in half. Compression tests (up to 2000 N) assessed sensor performance in terms of linearity (R² = 0.998 intact vs. 0.989 trimmed), repeatability (0.9% intact vs. 0.8% trimmed), and accuracy (1.7% intact vs. 2.3% trimmed) for forces up to 250 N. Higher force levels resulted in increased errors, but at a rate still comparable to that of existing sensors in the literature. Key considerations for the design of the instrumented prosthesis, such as minimizing point and shear loads, were identified. A prototype prosthesis capable of housing the sensor was proposed. The integrated system shows potential for improving the understanding of Total knee arthroplasty (TKA) failures through in vitro studies and could serve as an intraoperative tool for the evaluation of bone resections. Full article

The stability of the tibial component in Total Knee Arthroplasty (TKA) is critical to preventing aseptic loosening, a major cause of implant failure. However, existing tibial stem designs often lead to stress shielding and bone resorption, highlighting the need for further optimization. This study addresses these challenges by employing the Design of Experiments (DOE) methodology, specifically utilizing a full factorial design approach combined with finite element analysis (FEA), to optimize the geometry of the tibial stem. The material properties of the cortical and cancellous bone, as well as the tibial tray, were assigned based on values from the literature, representing their elastic moduli and Poisson’s ratios. For boundary conditions, the distal end of the tibia was fully constrained to simulate realistic load transfer, while compressive loads representative of walking and daily activities were applied to the tibial base. Key design parameters, including stem diameter, length, mediolateral ratio (M/L ratio), and wing angle, were systematically analyzed. The results identified stem diameter and length as the most influential factors in improving biomechanical performance, while the wing angle showed minimal impact. The optimized design, featuring a stem diameter of 12 mm, length of 40 mm, M/L ratio of 0.61, and a wing angle of 60°, demonstrated significant reductions in stress shielding and aseptic loosening compared to conventional models. These findings provide valuable insights into enhancing the long-term success of TKA implants by balancing implant stability and minimizing bone resection. Full article

Abstract: Objective: This study aimed to predict the orientation of the prosthetic trochlear angle (PTA) relative to the quadriceps line of force (QLF) in kinematically aligned total knee arthroplasty (KA-TKA) by using preoperative radiographic parameters. Methods: This study included 144 patients who underwent KA-TKA with a femoral component designed for mechanical alignment (MA_DFC), with a PTA of 6°. Radiographic parameters, including the lateral distal femoral angle (LDFA) and the QLF^FMA (quadriceps line of force–femoral mechanical axis angle), were measured pre- and postoperatively. We developed and validated a formula to predict PTA orientation based on these values: “X = QLF^FMA−(PTA−(90°−LDFA))”, where values of x > 0° predict a lateral PTA orientation, while x < 0° predicts a medial PTA. Results: The formula accurately predicted PTA orientation in 100% of the cases, with a difference between the predicted and actual PTA values of <0.5° in 75% of the cases. Patients with an LDFA < 86° and lower QLF^FMA values were identified as at risk for medial PTA orientation, which can affect patellar tracking. Conclusions: Our formula offers a reliable preoperative tool for predicting PTA orientation in KA-TKA, aiding in component selection and alignment strategies to improve patellofemoral function and patient outcomes. Full article

Instability remains one of the most common indications for revision after total knee arthroplasty. To gain a better understanding of how an implant will perform in vivo and support surgeons in selecting the most appropriate implant design for an individual patient, it is crucial to evaluate the implant constraint within clinically relevant ligament and boundary conditions. Therefore, this study investigated the constraint of three different implant designs (symmetrical implants with and without a post-cam mechanism and an asymmetrical medial-stabilized implant) under anterior–posterior shear forces and internal–external rotation moments at different flexion angles in human cadaveric knees using a six-degrees-of-freedom joint motion simulator. Both symmetrical designs showed no significant differences between the anterior–posterior range of motion of the medial and lateral condyles. In contrast, the medial-stabilized implant exhibited less anterior–posterior translation medially than laterally, without constraining the medial condyle to a fixed position. Furthermore, the post-cam implant design showed a significantly more posterior position of the femoral condyles in flexion compared to the other designs. The results show that despite the differences in ligament situations and individual implant positioning, specific characteristics of each implant design can be identified, reflecting the different geometries of the implant components. Full article

Background/Objectives: Patient-specific instrumentation (PSI) in total knee arthroplasty (TKA) uses preoperative three-dimensional imaging to create cutting blocks tailored to patient anatomy. However, there is debate regarding the additional benefits of PSI in terms of improved alignment or functional outcomes compared to using conventional instruments. Although PSI design has undergone continuous development, the improvements have not been incorporated. Therefore, the aim of this study was to compare the surgical time and radiological outcomes between advanced-design PSI and conventional instruments. Methods: We conducted a retrospective review of 328 patients who underwent primary TKAs using PSI for osteoarthritis and compared them with 328 matched patients who underwent TKA performed with conventional instruments during the same period (March 2023 to August 2024). We compared the surgical time and component alignment between the advanced-design PSI group and the conventional instrument group. Results: The average surgical time was significantly shorter in the advanced-design PSI group (47.6 ± 12.4 min) compared to the conventional instrument group (59.2 ± 14.2 min, p < 0.05). The advanced PSI design group had a significantly lower occurrence of outliers in hip–knee–ankle alignment (7%) compared to the conventional instrument group (36.3%). This trend was also observed in femoral coronal alignment, tibial coronal alignment, and femoral sagittal alignment. Conclusions: The use of advanced-design PSI demonstrated significantly reduced surgical time and improved alignment compared to conventional instruments. This highlights that proper design is a key factor for PSI to achieve superior biomechanical effects. Our study shows that advanced-design PSI technology has the potential to replace conventional instruments in TKA, though further research is required to determine its clinical outcomes and economic benefits. Full article

The optimal procedure for isolated end-stage medial compartment knee osteoarthritis (OA) remains uncertain, with debate persisting between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The aim of this narrative review is to evaluate current outcome measures in knee arthroplasty (KA) and explore how evolving patient populations and technological advancements may necessitate the use of different patient-reported outcome measures (PROMs) for evaluating UKA. While UKA offers potential advantages over TKA in early pain relief and functional outcomes, most randomised control trials using traditional PROMs have failed to show definitive superiority. The recent introduction of robotic assistance may have further enhanced the benefits of UKA. However, it remains uncertain whether the advantages outweigh the higher revision rates associated with UKA. Although traditional PROMs, such as the Oxford Knee Score or Knee Injury and Osteoarthritis Outcome Score, were designed for the KA population of 30 years ago, they continue to be employed today. The current KA population, particularly those undergoing UKA, are typically younger, physically fitter, and have higher functional demands than those for whom traditional PROMs were originally designed. As a result, these PROMs are now limited by ceiling effects. High-performance PROMs, such as the Forgotten Joint Score-12 or the metabolic equivalent of task score, have recently been utilised for high-demand patients and do not have postoperative ceiling effects. Return to work and sport are also important outcomes that are often overlooked for younger, high-demand patients. Future studies should aim to define the differences between UKA and TKA populations, identify patient factors that predict UKA success, and validate high-performance PROMs for UKA. This will provide deeper insights into the functional benefits of UKA and TKA, enabling patients and surgeons to make more informed decisions regarding implant selection. Full article

Background/Objectives: Abnormalities in patellar tracking, often overlooked in surgical planning, have been identified as a contributing factor to total knee arthroplasty (TKA) complications, including anterior knee pain, patellar subluxation, and dislocation. This study aims to evaluate the repeatability of a novel intraoperative setup for assessing patellofemoral kinematics and its interaction with prosthesis design and positioning during surgery. This setup may support personalized alignment techniques in TKA, potentially improving surgical outcomes. Methods: Kinematic data were collected under both native and post-TKA conditions, and the Repeatability Coefficient (RC), Intraclass Correlation Coefficient (ICC), and Limits of Agreement of the Mean were calculated to assess measurement reliability. Results: RC values indicated high repeatability, with patellar flexion averaging an RC of 1°. Rotation and tilt demonstrated an RC below 1° post-mid-flexion, while patellar shift maintained an RC of approximately 1.6 mm. ICC and the extended Bland and Altman analysis showed an excellent agreement (ICC > 0.9) and an expected mean difference of zero for all the measured parameters. Measurements were consistent across both flexion and extension, and between native and post-TKA conditions. Conclusions: The proposed setup for intraoperative patellofemoral kinematic assessment demonstrated high repeatability and practical utility. The approach was found to be non-intrusive to patellar motion tracking and can be robustly integrated into the intraoperative workflow. This method provides a reliable approach for real-time patellar tracking, which may contribute to more personalized and precise TKA procedures, potentially reducing post-surgical dissatisfaction and complications. Full article

Background: Meta-analyses and randomized controlled trials were inconclusive regarding the role of gabapentinoids in patients undergoing joint arthroplasties. The aim of the present study was to investigate the effect of a preoperative low dose of gabapentin in patients undergoing total hip (THA) and knee arthroplasties (TKA). Methods: A retrospective observational study was conducted on 135 patients undergoing THA and TKA at the National Orthopedic Hospital Cappagh, Dublin, from July to December 2022. The primary outcome was the assessment of numerical rating scores (NRS) for postoperative pain at various time intervals. Results: During the observation period, 55 patients received a preoperative dose of gabapentin, while 80 patients did not. Statistically significant differences in numerical rating scores (NRS) were found at 6 (3 vs. 0, p < 0.001), 12 (4 vs. 2, p < 0.001), 18 (4 vs. 3, p < 0.001), and 24 h (4 vs. 3, p = 0.010) after surgery, in favor of the group receiving gabapentin. A reduction in opioid consumption, measured as morphine equivalents, was also noted in the gabapentin group (40 vs. 30 mg, p = 0.040). Conclusions: A low preoperative dose of gabapentin was associated with reduced postoperative pain and opioid consumption in patients undergoing TKA and THA, without impacting hospital stay. Prospectively designed trials are encouraged to assess the safety and effect on pain control of a preoperative low dose of gabapentin. Full article