Search Results (52)

Total knee arthroplasty (TKA) remains a cornerstone of orthopedic surgery, with optimal coronal alignment playing a pivotal role in determining both clinical outcomes and implant longevity. Traditionally, mechanical alignment has been regarded as the gold standard. However, the emergence of alternative philosophies—such as kinematic alignment and hybrid techniques—has shifted the focus toward individualized approaches. Recent advancements in robotic and computer-assisted systems have significantly enhanced the precision of implant positioning, allowing surgeons to better replicate native knee biomechanics and improve patient satisfaction. This narrative review examines current alignment philosophies in TKA, including mechanical, kinematic, and hybrid methods. It analyzes each technique’s principles, functionalities, benefits, and limitations while highlighting ongoing debates regarding their clinical application. Special attention is given to the role of technology in enabling more accurate, patient-specific surgical execution. Despite promising developments, challenges remain in standardizing these techniques and validating their long-term efficacy. To ensure a comprehensive evaluation relevant literature was reviewed, focusing on studies that explore alignment strategies, biomechanical outcomes, and the integration of technology in TKA. This review aims to synthesize current evidence, identify gaps in knowledge, and outline directions for future research needed to optimize alignment strategies in modern knee arthroplasty. Full article

Background: Robotic-assisted systems have transformed total knee arthroplasty (TKA), promising improved accuracy and intraoperative consistency, yet real-world data from non-academic centers remain limited. Objective: This study evaluates five-year clinical integration of a semi-autonomous, CT-based, robotic-arm-assisted TKA at a tertiary non-teaching hospital in Germany, focusing on planning accuracy, gap balancing, and intraoperative outcomes. Methods: We retrospectively analyzed all patients (n = 457) who underwent MAKO-assisted TKA from 2020 to 2025, performed by three orthopedic surgeons using a standardized subvastus approach. We assessed preoperative deformities, intraoperative alignment, implant sizing, and gap balancing. Surgical plans were adapted intraoperatively when indicated. Pre- vs. post-implantation values were compared using slopes to evaluate execution consistency. Results: Median patient age was 67.0 years (IQR: 60.0–75.0), with varus in 84.1% (7.0°, IQR: 4.0°–10.0°), valgus in 13.2% (3.0°, IQR: 1.5°–5.8°), and neutral alignment in 2.7%. Flexion contracture occurred in 80.4% (6.0°, IQR: 3.0–10.0%), hyperextension in 12.7% (2.0°, IQR: 1.5°–5.0°). Planning-to-execution consistency was high, even with plan adaptations. Slope values for alignment parameters were: tibial rotation in degrees (slope value: 1.0), femoral sagittal angle in degrees (0.8), tibial sagittal angle in degrees (0.9), coronal posterior condylar angle in degrees (0.9), femoral component size (1.0), tibial component size (1.0). Over 95% of cases showed ≤3.0° deviation between planned and final values. Bone resection concordance showed moderate agreement, with slopes from 0.8 (posterior medial femoral cut in mm) to 0.5 (lateral tibial cut in mm). Gap balancing improved at all stages, with reduced variability in medial/lateral extension and flexion gaps (all p < 0.05). Functional reconstruction showed significant improvements in extension, flexion, and deformities (all p < 0.001). Conclusions: Semi-autonomous, CT-based, robotic-arm-assisted TKA was successfully implemented in this non-academic setting, demonstrating acceptable intraoperative and functional reconstruction outcomes, supporting the feasibility of robotic-assisted surgery outside academic centers. Full article

Background: Lower limb malalignment is a hallmark of knee osteoarthritis, with surgical correction techniques evolving from traditional mechanical alignment (MA) to kinematic alignment (KA) approaches. Restrictive kinematic alignment (rKA) represents a hybrid strategy combining principles from both techniques. This study evaluated short-term functional outcomes following robotic-assisted total knee arthroplasty (RoTKA), comparing MA versus rKA alignment strategies. Methods: This prospective, randomized, single-center study enrolled 96 patients with grade 3–4 idiopathic knee osteoarthritis (Kellgren–Lawrence classification). Patients were randomized to MA (n = 49, mean age 67 ± 9 years) or rKA (n = 47, mean age 66 ± 7 years) groups. Preoperative hip–knee–ankle (HKA) angles were 172.6° ± 1.1° and 172.9° ± 0.9° for MA and rKA groups, respectively. Outcomes were assessed using Visual Analog Scale (VAS) pain scores, range of motion (ROM), Knee Society Score (KSS), Oxford Knee Score (OKS) (primary outcome), SF-36, and Forgotten Joint Score (FJS-12). Results: Postoperative HKA angles were 179.5° ± 1.2° (MA) and 176.0° ± 1.5° (rKA). At 14 days postoperatively, knee ROM increased by 20.5% in the MA group and 25.7% in the rKA group, with a statistically significant 5.2% intergroup difference, indicating faster postoperative recovery (p = 0.008). VAS pain scores decreased by 7% in the rKA group while increasing by 13% in the MA group (p < 0.001). At one-year follow-up, FJS-12 scores were significantly higher in the rKA group (94.8 ± 3.2 vs. 91.9 ± 2.2, p < 0.001). No significant differences were observed in KSS, OKS, or SF-36 score between groups. Conclusions: Restrictive kinematic alignment demonstrated superior early postoperative outcomes compared to mechanical alignment in RoTKA, with significantly reduced pain and improved ROM. While one-year functional outcomes were comparable between techniques, rKA may offer advantages in the immediate postoperative period, supporting its consideration as a viable alignment strategy in robotic-assisted knee arthroplasty. Full article

Background and Objectives: Performance of robot-assisted total knee arthroplasty (TKA) procedures has continued to increase in popularity. However, tourniquet use is necessary for longer periods of time in robot-assisted TKA than conventional manual TKA because the robot-assisted procedure requires an additional registration process. The use of tourniquets for long periods increases the risk of hidden blood loss and ischemic soft tissue injury in the lower extremity. The purpose of this study was to compare the value of performing robot-assisted TKA without the use of a tourniquet to that of performing this surgery with the use of a tourniquet. Parameters we assessed were blood loss, degree of postoperative thigh and knee pain, and occurrence of early post-operative complications. Materials and Methods: Data from 100 consecutive patients who underwent primary unilateral robot-assisted TKA between July 2024 and July 2025 were included in this study’s analyses. Patients were divided into three groups chronologically. The first 29 patients comprised group 1, the early tourniquet group; the next 30 patients were assigned to group 2, the no tourniquet group; and group 3 was the late tourniquet group and comprised the remaining 41 subjects. However, because allocation was chronological rather than randomized, the outcomes of later groups may partly reflect the surgeon’s accumulated experience (learning curve), which should be considered when interpreting the results. The primary outcome measure was estimated blood loss (EBL). The secondary outcome measures included transfusion rate, visual analog scale (VAS) pain scores for the knee and thigh on the third postoperative day, readmission rate due to surgical complications, superficial and deep infection rate, length of operation, and length of tourniquet use. Results: Group 2 participants, the no tourniquet participants, experienced significantly greater EBL on postoperative days (PODs) 1, 2, and 3 compared to the subjects assigned to groups 1 and 3 (p = 0.003, p < 0.001, and p = 0.005, respectively). However, there were no significant differences in transfusion rates (p = 0.290) among the 3 groups. VAS scores for knee and thigh pain were also not significantly different among the three groups (all p-values > 0.05). Three patients in group 1 (10.3%), one patient in group 2 (3.3%), and one patient in group 3 (2.4%) were readmitted for complications related to wound healing (p = 0.289). Additionally, two patients in group 1 developed superficial wound infections from which the causative bacteria were cultured. No infections were observed in the other groups (p = 0.082), however. Two patients in group 1 and two patients in group 2 experienced symptomatic deep vein thrombosis (DVT) (p = 0.235). No group 3 patients experienced DVT, and only one patient in group 2 was confirmed with DVT using an enhanced CT scan (p = 0.308). Group 3 patients had shorter lengths of surgery (p < 0.001) than group 1 and 2 patients and had shorter periods of tourniquet use (p = 0.034) than group 1 patients. Conclusions: Tourniquet non-use in robot-assisted TKA surgeries was associated with greater EBL in acute postoperative periods, but this finding was not accompanied by any change in transfusion rate. Tourniquet non-use was not clinically beneficial for reducing immediate postoperative thigh and knee pain or reducing the prevalence of early post-operative complications. Tourniquet use in robot-assisted TKA may be beneficial because of the advantages its use provides in maintaining a clear surgical field and in facilitating the cementing process. Full article

Purpose: This review examines the recent literature on total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) published in the Knee Surgery Sports Traumatology and Arthroscopy (KSSTA) journal in 2023. The aim was to identify key research themes, advancements, and global contributions to knee surgery research. Methods: Articles published in KSSTA in 2023 were identified through a structured database search using the term “knee OR TKA OR UKA”. Inclusion criteria focused on primary studies, reviews, and case reports in English related to TKA or UKA. Data were extracted and synthesized thematically to analyze research trends and gaps. Results: The search yielded to 75 articles, 63 focused on TKA and 12 on UKA. Most contributions originated from Europe, followed by Asia and North America. Robotic-assisted TKA emerged as a significant advancement, enhancing surgical precision but requiring further validation through extended follow-up studies. Personalized implants showed potential for improved outcomes, though cost-effectiveness remains a concern. In UKA, slight overcorrection during alignment was associated with better functional results. Conclusions: The literature in the 2023 KSSTA highlights journal-specific trends and innovations in knee surgery. While techniques like robotic TKA and personalized implants are promising, further research is essential to standardize protocols and evaluate long-term impacts, emphasizing the need for sustained research efforts in knee orthopedics. Full article

Total knee arthroplasty is an extensive orthopedic surgery for patients with severe cases of osteoarthritis. This surgery restores the range of motion in the knee joint and allows for pain-free movement. Advancements in medical techniques used in the surgical zone and implant technology, as well as the management of operations and administration for around two decades prior, have hugely improved surgical outcomes for patients. In this study, advancements in TKA were examined through exploring aspects such as robotic surgery, new implants and materials, minimally invasive surgery, and post-surgery rehabilitation. This paper entails a review of the peer-reviewed literature published between 2005 and 2025 in the PubMed and Google Scholar databases. For predictors, we incorporated clinical relevance together with methodological soundness and relation to review questions to select relevant research articles. We used the PRISMA flowchart to illustrate the article selection system in its entirety. Since robotic surgical and navigation systems have been implemented, surgical accuracy has improved, there is an increased possibility of ensuring alignment, and the use of cementless and 3D-printed implants has increased, offering durable long-term fixation features. The trend in the current literature is that minimally invasive knee surgery (MIS) techniques reduce permanent pain after surgery and length of hospital stays for patients, though the long-term impact still needs to be established. There is various evidence outlining that the enhanced recovery after surgery (ERAS) protocols show positive results in terms of functional recovery and patient satisfaction. The integration of these new advancements enhances TKA surgeries and translates them into ‘need of patient’ procedures, ensuring improved results and increases in patient satisfaction. The aim of this study was to perform a comprehensive analysis of the existing literature regarding TKA advancement studies to identify current gaps and problems. Full article

Background: The ROSA Knee System (Zimmer Biomet, Warsaw, IN, USA) is a robotic system aiming to increase bone resections and component alignment accuracy during TKA. While much is known about its performance in the coronal plane, its accuracy in the sagittal plane remains debated. The present investigation evaluated the system’s accuracy in achieving planned mechanical axis alignment and specific knee angles in both planes. Methods: A retrospective analysis was performed on 55 consecutive patients who underwent robotic-assisted TKA using the ROSA Knee System. Data on the medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), hip–knee–ankle angle (HKA), tibial slope (TS), and distal femoral flexion (DFF) were collected pre- and post-operatively using the ROSA software. Planned and achieved angles were compared, with deviations greater than 2° and 3° defined as outliers. Results: The mean differences between planned and achieved angles for LDFA and MPTA were 0.5° ± 1.00° and 0.3° ± 1.3°, respectively, with less than 10% outliers. The hip–knee angle recorded only a minimal deviation from planned values. In contrast, the TS angle showed a statistically significant difference between planned and achieved values, while no significant difference was found for the DFF angle. The surgeon’s experience did not impact alignment accuracy. Conclusions: The ROSA Knee System demonstrates high accuracy in achieving planned alignment in the coronal plane during robotic-assisted TKA, with minimal outliers and reliable predictions for both femoral and tibial angles. However, the ROSA Knee System showed less accuracy in the sagittal plane, particularly for the tibial slope, which did not adversely affect the implant’s stability. Full article

Background/Objectives: Total knee arthroplasty (TKA) is an effective surgical intervention for end stage knee osteoarthritis in elderly patients, with emerging robotically assisted techniques aiming to enhance surgical precision and patient outcomes. This study aimed to compare medium-term balance and functional outcomes between robotically assisted and conventional manual TKA in community-dwelling elderly patients. Methods: This cross-sectional study included 50 elderly patients undergoing TKA, who were divided into robotically assisted (n = 25) and conventional manual (n = 25) groups. Demographic and clinical data, balance performance, and functional outcomes were compared at nearly 1.5 years postoperatively. Outcome measures included balance performance assessed by the Berg Balance Scale (BBS), pain via the Visual Analog Scale (VAS), knee function as measured by the Lysholm Knee Scoring Scale, quality of life using the Short Form-12 (SF-12), joint awareness as evaluated by the Forgotten Joint Score-12 (FJS-12), and surgical satisfaction. Results: The groups had similar demographic and clinical data regarding age, gender, follow-up duration, surgical time, and anesthesia type (p > 0.05). The robotically assisted group demonstrated better balance performance on the BBS (p = 0.043) and had a statistically shorter length of hospital stay (1.22 vs. 1.42 days; p = 0.005). However, no statistically significant differences were observed in VAS activity pain (p = 0.053), Lysholm Knee Scoring Scale (p = 0.117), SF-12 physical and mental scores (p = 0.174 and p = 0.879), FJS-12 (p = 0.760), and surgical satisfaction (p = 0.218). Conclusions: Robotically assisted TKA is associated with advantageous postoperative recovery, particularly in terms of balance performance, showing no clinical difference in other functional outcomes compared to the conventional manual technique. From a physical therapy perspective, these findings emphasize the importance of developing tailored and effective rehabilitation strategies in the medium term for functional recovery in the elderly population. Full article

Background: Robotic-assisted technology has become an increasingly utilized adjunct within the realm of primary total knee arthroplasty (TKA). Previous studies have shown that robotic-assisted total knee arthroplasty (raTKA) offers potential advantages of enhanced bony preparation and optimal implant alignment with equivalent long-term patient outcomes and component longevity in comparison to conventional TKA (cTKA). Furthermore, recent studies have identified the additional benefit of decreased surgeon physiologic stress with the use of raTKA. The purpose of this study was to compare differences in surgeon posture between primary raTKA and cTKA. Materials and Methods: We prospectively evaluated 103 consecutive primary TKA cases (48 raTKAs, 55 cTKAs) performed by three high-volume, fellowship-trained arthroplasty surgeons. Throughout each case, surgeons wore a posture-tracking device to evaluate time spent slouching. The threshold for slouching was set to 30 degrees of flexion from a neutral spinal axis. Demographic and operative factors were collected. Two-tailed tests and multivariate analysis were used to assess for differences between groups. Results: After controlling for individual surgeon differences in posture, we found a decrease in the percentage and duration of time spent slouching in raTKA cases compared to cTKA cases (42.4 vs. 72.5%, p < 0.001, 35.4 vs. 54.7 min, p = 0.037). On average, the use of the robot decreased surgeon slouching time by 19.3 min (26.6%, p < 0.001). Patient factors such as increased age and ASA 2 were also associated with favorable effects on posture (p < 0.001). Conclusions: Surgeons performing primary raTKA cases spend significantly less case time and case percentage in a slouched posture compared to conventional primary TKA cases. This suggests the potential for ergonomic benefit of robotic-assisted technology in primary TKA. Further research is needed to determine the long-term effects of posture on surgeon pain and career longevity. Full article

Background/Objectives: Total knee arthroplasty (TKA) is a common procedure for knee osteoarthritis. While conventional TKA (C-TKA) remains standard, robot-assisted TKA (RA-TKA) has been introduced to enhance implant positioning and clinical outcomes. However, its comparative benefits remain unclear. This systematic review and meta-analysis compared RA-TKA with C-TKA, examining the influence of robotic system, surgeon experience, and follow-up duration. Methods: A systematic search was conducted across the PubMed, Scopus, Web of Science, and Cochrane Library databases. Randomized controlled trials (RCTs) comparing RA-TKA with C-TKA were included. Outcomes were categorized into clinical, radiographic, and safety endpoints. Subgroup and meta-regression analyses explored factors influencing outcome variability, including robotic system, number of surgeons, and follow-up duration. Results: Twenty-five RCTs (5614 patients) were analyzed. RA-TKA showed modest improvements in clinical outcomes, such as KSS and VAS pain scores, but results varied across subgroups. RA-TKA demonstrated a significantly better flexion range of motion (ROM) in certain countries (e.g., Russia, MD = 10; 95%CI: 5.44, 14.56) and with specific robotic systems (e.g., NAVIO). No significant differences were found in OKS and HSS scores. Radiographic outcomes, including the HKA Angle, varied by robotic system, with NAVIO and YUANHUA showing better alignment than C-TKA. Complication rates were comparable, though RA-TKA had a higher risk of conversion to open surgery (10% vs. 2%). Meta-regression identified robotic system and surgeon experience as key predictors of outcome variability. Conclusions: RA-TKA offers advantages in implant alignment and postoperative pain reduction. However, benefits are inconsistent across settings, and some robotic systems may not provide improvements over C-TKA. Full article

Background: Robot-assisted total knee arthroplasty (TKA) has gained attention for its ability to improve surgical precision, optimize component alignment, and potentially enhance functional outcomes. Despite these advantages, early postoperative deficits, particularly in quadricep activation and the range of motion (ROM), remain common and can delay recovery. The objective of this study was to investigate early postoperative differences in quadricep muscle activation and the ROM between the operated and non-operated sides following robot-assisted TKA. Methods: A total of 101 participants (50 females, 51 males) were included in the study. Surface electromyography (sEMG) was recorded from the vastus lateralis and vastus medialis during an active knee extension test and a 4-m walking test. The ROM was assessed during gait. A linear mixed model was employed with operated side and sex as factors. Results: Significant differences were observed in quadricep muscle activation and the ROM between the operated and non-operated sides. During the knee extension test, males exhibited significantly higher vastus lateralis activity on the non-operated side (mean difference = 174 µV, 95% confidence interval (CI) [90, 258], p < 0.001) and females showed a similar pattern (mean difference = 238 µV, 95% CI [152, 324], p < 0.001). Additionally, vastus medialis activation was significantly higher on the non-operated side for both males (mean difference = 102 µV, 95% CI [34, 169], p = 0.003) and females (mean difference = 137 µV, 95% CI [47, 226], p = 0.003). During the 4-m walking test, females displayed a significantly reduced sagittal-plane ROM on the operated side (mean difference = 7.691°, p = 0.041) whereas no significant ROM differences were found in males (p > 0.903). Conclusions: Robot-assisted TKA patients exhibit significant early postoperative asymmetries in quadricep activation and the gait ROM, particularly among females. Full article

Many new technologies focused mainly on improving surgical accuracy were first developed in total knee arthroplasty and have not yet shown significant value. These non-significant clinical improvements could potentially be explained by an inadequate target. In this current concept paper, the authors will describe how artificial intelligence (AI), robotic-assisted surgery, and custom implants allow the definition of new targets and the standardization of the TKA process. As paradoxical as it may be, new technologies in TKA will allow for better standardization in the overall way in which this procedure is carried out. Achieving this goal can be accomplished by incorporating AI-driven tools into the medical field. These tools are intended to enhance decision making, refine surgical planning, and increase the precision and consistency of surgical procedures. Moreover, custom implants with personalized alignment, beyond restoring native anatomy, will define new targets and standardize the whole TKA process. Full article

Background: Robotic-assisted total knee arthroplasty (rTKA) has been introduced to improve surgical precision and alignment in knee replacement procedures. However, its impact on clinical outcomes, pain relief, and cost-effectiveness remains debated. This umbrella review synthesizes evidence from systematic reviews and meta-analyses comparing rTKA to conventional TKA. Methods: An umbrella review was conducted in PubMed, Scopus, Web of Science, Embase, and the Cochrane Database of Systematic Reviews. Systematic reviews and meta-analyses comparing rTKA with conventional TKA were included. Methodological quality was assessed using AMSTAR 2 and ROBIS tools. Primary outcomes included hospital stay, radiographic alignment, postoperative pain, functional outcomes, and patient satisfaction. Results: Ten systematic reviews were included. rTKA demonstrated superior alignment accuracy and a reduction in alignment outliers. Some studies reported shorter hospital stays and lower early postoperative pain scores for rTKA. However, these benefits did not consistently translate into improved long-term functional outcomes, patient satisfaction, or reduced revision rates. Cost-effectiveness analyses indicated that rTKA remains an expensive option, with benefits largely dependent on surgical volume and healthcare system resources. Conclusions: While rTKA improves surgical precision and may offer short-term advantages, its long-term superiority over conventional TKA remains unproven. Higher costs and longer operative times limit its widespread adoption. Further high-quality, long-term studies are needed to determine its clinical and economic value. Full article

Background: This study compared the early rehabilitation progress of patients undergoing robotic-assisted medial unicompartmental knee arthroplasty (mUKA) and robotic-assisted kinematically aligned total knee arthroplasty (rKA-TKA), focusing on daily activity by step-count measurements. Methods: A retrospective analysis of prospectively collected data from 88 patients (53 rKA-TKA and 35 mUKA) was conducted. Patients wore Garmin Vivofit^® 4 activity trackers pre and postoperatively. Daily step counts were analyzed, and clinical outcomes were assessed using various scores, including the Knee Society Score (KSS) and Forgotten Joint Score (FJS). Results: Preoperative median daily step counts were comparable between groups (rKA-TKA: 3988 and mUKA: 4315; p = 0.128). At 6 and 7 weeks post-surgery, the mUKA group showed significantly higher median step counts (3741 and 4730) compared to the rKA-TKA group (2370 and 2910), with p-values of 0.015 and 0.048, respectively. The mUKA group reached 86.7% of their preoperative step count at week 6 and 100% at week 7, while the rKA-TKA group achieved 59.4% and 73%, respectively. Both groups surpassed their preoperative activity levels by week 9. Clinical outcomes at 2 months and 1 year post-surgery showed no significant differences between groups. Conclusions: While both the mUKA and rKA-TKA patients achieved their preoperative daily activity levels within nine weeks post-surgery, the mUKA patients reached this milestone approximately two weeks earlier. This study demonstrates a clinical benefit of mUKA in terms of faster postoperative remobilization, even when compared to kinematically aligned robotic-assisted TKA. Full article

Background: The objective of this study was to compare the outcomes between patients undergoing mechanically aligned conventional total knee arthroplasty (MA-CTKA) and functionally aligned robotic-arm-assisted TKA (FA-RTKA). Methods: We reviewed a prospectively collected database of consecutive patients who underwent primary total knee arthroplasty (TKA) for knee osteoarthritis between June 2022 and May 2023. Patients were divided into two groups—MA-CTKA (n = 50) and FA-RTKA (n = 50)—based on the introduction of a robotic-arm-assisted system during the study period. The hip–knee–ankle (HKA) angle, joint line orientation angle (JLOA) relative to the floor, and weight-bearing line (WBL) ratio were evaluated using full-length standing hip-to-calcaneus radiographs to compare the conventional mechanical axis (MA) and the ground mechanical axis (GA) passing through the knee joint between the groups. Clinical outcomes were also compared between the two groups. Results: There were no significant differences in the postoperative HKA angle between the groups, due to discrepancies in the targeted alignment strategies (FA-RTKA: 2.0° vs. MA-CTKA: 0.5°; p = 0.001). The postoperative JLOA in the FA-RTKA group was more parallel to the floor, whereas the MA-CTKA group showed a downward angulation toward the lateral side (0.6° vs. −2.7°; p < 0.001). In the FA-RTKA group, the GA passed through a neutral position when accounting for the calcaneus, while the MA-CTKA group showed a more lateral GA position (48.8% vs. 53.8%; p = 0.001). No significant differences in clinical outcomes were shown between the FA-RTKA and MA-CTKA groups, with the FA-RTKA group demonstrating higher Forgotten Joint Scores and a greater range of motion (all p < 0.05). Conclusions: Functionally aligned TKA demonstrated improved joint line parallelism to the floor and more neutral weight-bearing alignment in the GA compared to mechanically aligned TKA. These findings indicate a more balanced load distribution across the knee, which may contribute to the superior clinical outcomes observed in the functionally aligned group. Full article