Conventional Total Knee Arthroplasty Research Articles

Preoperative evaluation of femoral and tibial sagittal alignment in robotic-assisted and conventional total knee arthroplasty and consequences for practice.

Robot-assisted total knee arthroplasty (TKA) was developed to improve the precision and accuracy of implant placement in conventional TKA. However, the angular differences between referenced axes in robot-assisted TKA and conventional TKA remain unclear. The aim of this study was to investigate the angular differences in sagittal alignment between robot-assisted TKA and conventional TKA for both the femur and the tibia and to discuss their clinical implications. We conducted a retrospective analysis of data from 100 patients (97 patients) who underwent computed tomography (CT) for Mako TKA. We measured the angle between the robot femoral axis (RFA) and conventional femoral axis (CFA) in the sagittal plane and the angle between the robot tibial axis (RTA) and the conventional tibial axis (CTA). Angles were compared between the sexes. Correlation analysis was conducted between the angles and height. In the sagittal plane, the mean RFA-CFA angle was 2.2° ± 1.6°, and the mean RTA-CTA angle was 2.3° ± 1.6°. There were no significant differences between the two angles among males and females (p > 0.05). There was a correlation between the RFA-CFA angle and RTA-CTA angle (p < 0.001, r = 0.33), and there was a correlation between height and the combination of the RFA-CFA angle and RTA-CTA angle (p = 0.03, r = 0.22). There are angular differences between the axes referenced by robot-assisted TKA and those referenced by conventional TKA, which may be influenced by patient height. Correctly understanding these differences is crucial when evaluating the implant position and surgical outcomes after robot-assisted TKA. Furthermore, caution should be taken when assessing the flexion-extension angle of the knee since the angles displayed in the Mako system are different from the angles measured with intramedullary anatomical axes. After all, sagittal alignment principles differ between robot-assisted and conventional TKA; however, further studies are required to determine which principle is more appropriate or to modify these principles.

A commentary on "Association of postoperative outcomes with geriatric nutritional risk index after conventional and robotic-assisted total knee arthroplasty: a randomized controlled trial".

A commentary on "Association of postoperative outcomes with geriatric nutritional risk index after conventional and robotic-assisted total knee arthroplasty: a randomized controlled trial".

Robot-assisted total knee arthroplasty system provides more precise control of the femoral rotation angle: A retrospective study.

Rotational alignment in total knee arthroplasty (TKA) is a crucial technical point that needs attention. We conducted a retrospective study to investigate whether a new robot-assisted TKA (RA-TKA) could improve the accuracy of rotational alignment and whether rotational alignment affects postoperative pain and functional evaluation of the knee. A total of 136 consecutive patients who underwent TKA were included in this study. Half of the patients underwent RA-TKA and the other half underwent conventional TKA (CON-TKA) by the same group of surgeons. Collect the relevant parameters. The postoperative femoral rotation angle (FRA) was -0.72±2.59° in the robot-assisted group and 1.13±2.73° in the conventional group, and were statistically significantly different (p<0.001). This study provides preliminary evidence that the RA-TKA provides more precise control of FRA than CON-TKA, and verifies that tibial rotation angle and combined rotation angle affect postoperative knee pain and functional evaluation.

Enhanced recovery after surgery day surgery for MAKO® robotic-arm assisted TKA; better outcome for patients, improved efficiency for hospitals

IntroductionRobotic-assisted Total Knee Arthroplasty (TKA) was designed to improve implant position accuracy by providing surgeons with real-time intra-operative data to tailor the operation to the patient. Proponents of robotic-assisted TKA believe that this translates into meaningful improvements in outcomes. However, there are concerns that the longer surgical duration associated with robotic-assisted TKA leads to longer length of stay (LOS). In this study, the authors investigated the outcome of MAKO® Robotic-arm Assisted TKA combined with ERAS protocol to assess its effect on LOS and short-term outcomes. MethodsAll patients who had undergone unilateral MAKO® ERAS Day Surgery TKA from August 2020 to July 2021 were prospectively followed up and matched to patients who underwent conventional ERAS Day Surgery TKA in the same time period. Factors such as surgical duration, LOS, immediate reduction in pain, 30-days complications, and 6-month PROMs and knee ROM were compared between the two groups. Results42 patients underwent MAKO® ERAS Day surgery TKA and were matched to 42 patients who underwent conventional ERAS Day surgery TKA. The study found that despite the longer surgical duration, LOS was comparable between both groups (1.1 ± 0.9days in the MAKO® group vs 1.0 ± 0.3days in the conventional group, p = 0.755) with successful 24-hour discharge in 88.1 % of patients in the MAKO® group. The MAKO® group achieved significantly better ROM compared to the conventional group 6-months post operatively. Post-operative PROMs were comparable between both groups. ConclusionERAS Day Surgery protocol can significantly reduce the LOS of patient undergoing MAKO® Robotic-arm Assisted TKA, conferring cost savings and making it a valid option for patients.

ROBOTIC-ASSISTED TOTAL KNEE ARTHROPLASTY IS ASSOCIATED WITH EARLIER RETURN OF SYMMETRICAL LIMB FUNCTION COMPARED WITH CONVENTIONAL TOTAL KNEE ARTHROPLASTY

IntroductionRobotic-assisted total knee arthroplasty (TKA) has demonstrated significant benefits, including improved accuracy of component positioning compared to conventional jig-based TKA. However, previous studies have often failed to associate these findings with clinically significant improvements in patient-reported outcome measures (PROMs). Inertial measurement units (IMUs) provide a more nuanced assessment of a patient's functional recovery after TKA. This study aims to compare outcomes of patients undergoing robotic-assisted and conventional TKA in the early postoperative period using conventional PROMS and wearable sensors.Method100 patients with symptomatic end-stage knee osteoarthritis undergoing primary TKA were included in this study (44 robotic-assisted TKA and 56 conventional TKA). Functional outcomes were assessed using ankle-worn IMUs and PROMs. IMU- based outcomes included impact load, impact asymmetry, maximum knee flexion angle, and bone stimulus. PROMs, including Oxford Knee Score (OKS), EuroQol-Five Dimension (EQ-5D-5L), EuroQol Visual Analogue Scale (EQ-VAS), and Forgotten Joint Score (FJS-12) were evaluated at preoperative baseline, weeks 2 to 6 postoperatively, and at 3-month postoperative follow-up.ResultsBy postoperative week 6, when compared to conventional TKA, robotic-assisted TKA was associated with significant improvements in maximum knee flexion angle (118o ± 6.6 vs. 113o ± 5.4; p=0.04), symmetrical loading of limbs (82.3% vs.22.4%; p&lt;0.01), cumulative impact load (146.6% vs 37%; p&lt;0.01), and bone stimulus (25.1% vs 13.6%; p&lt;0.01). Whilst there were no significant differences in PROMs (OKS, EQ-5D-5L, EQ-VAS, and FJS-12) at any time point between the two groups, when comparing OKS subscales, significantly more robotic-assisted TKA patients achieved an ‘excellent’ outcome at 6 weeks compared to conventional (47% vs 41%, p= 0.013).ConclusionsIMU-based metrics detected an earlier return to function among patients that underwent robotic-assisted TKA compared to conventional TKA that PROMs were unable to detect within the first six weeks of surgery.

Robotic assisted Total Knee Arthroplasty (TKA) is not associated with increased patient satisfaction: a systematic review and meta-analysis.

Total knee arthroplasty (TKA) is a common orthopedic surgery, yet postoperative dissatisfaction persists in around 20% of cases. Robotic total knee arthroplasty (rTKA) promises enhanced precision, but its impact on patient satisfaction compared to conventional TKA remains controversial (cTKA). This systematic review aims to evaluate patient satisfaction post-rTKA and compare outcomes with cTKA. Papers from the following databases were identified and reviewed: PubMed, Scopus, Web of Science, and the Cochrane Online Library, using keywords like "Knee replacement," "Total knee arthroplasty," "Robotic," and "Patient satisfaction." Extracted data included patient satisfaction measures, Knee Society Score, Oxford Knee Score, Forgotten Joint Score, SF-36, HSS, and KOOS. Statistical analysis, including odds ratio and 95% CI was performed using R software. Heterogeneity was assessed using Cochrane's Q test. The systematic review included 17 articles, involving 1148 patients (571 in the rTKA group and 577 in the cTKA group) assessing patient satisfaction following rTKA. An analysis of proportions reveals rTKA satisfaction rate was 95%, while for cTKA, it was 91%. A meta-analysis comparing rTKA and cTKA found no statistically significant difference in patient satisfaction. Additionally, various patient-reported outcome measures (PROMs) were examined, showing mixed results across different studies and follow-up periods. The results of this study found no difference in patient satisfaction outcomes in the short to mid-term for rTKA compared to conventional methods. This study does not assert superiority for the robotic approach, highlighting the need for careful consideration of various factors influencing outcomes in knee arthroplasty.

RESULTS OF ROBOTIC ASSISTED VS CONVENTIONAL TOTAL KNEE ARTHROPLASTY AT 1 YR FOLLOW UP

Background: Osteoarthritis (OA) of the knee is a prevalent condition among older individuals, causing significant discomfort and impairments in quality of life. Conventional total knee arthroplasty (COTKA) is a common treatment, but issues such as inadequate soft tissue balance and prosthesis misalignment can impact outcomes. Robotic-assisted total knee arthroplasty (RATKA) has emerged as a potential solution, offering enhanced precision in prosthesis placement. While observational studies suggest benefits, comprehensive reviews of randomized controlled trials (RCTs) are lacking. This study aims to fill this gap by evaluating the clinical, functional, and radiological outcomes of RATKA compared to COTKA in adult patients with primary knee OA. Methods: This prospective study was conducted at a specialized orthopedic center, involving patients diagnosed with symptomatic knee OA eligible for total knee replacement (TKR). Patients were allocated to either conventional TKR (Group A) or robotic-assisted TKR (Group B). Outcome measures included Visual Analog Scale (VAS) for pain, Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), patient satisfaction, and quality of life assessments. Radiological outcomes were assessed using standardized radiographs. Statistical analyses included descriptive statistics, group comparisons, and repeated measures analysis of variance (ANOVA). Results: Baseline characteristics showed similar distributions between Group A (n=30) and Group B (n=30). Clinical outcomes demonstrated significant improvements over time in both groups, with Group B consistently outperforming Group A across all measures. Notably, Group B exhibited lower pain scores (VAS), higher functional scores (KSS), lower disability scores (WOMAC), higher patient satisfaction, and better quality of life assessments. Radiological outcomes also favored Group B, with improved mechanical axis deviation and component positioning. Conclusion: Robotic-assisted TKR demonstrated superior clinical, functional, and radiological outcomes compared to conventional TKR in patients with knee OA. These findings support the growing body of evidence favoring the use of robotic technology in TKR procedures, particularly for optimizing implant placement and alignment. Future research should focus on cost-effectiveness and long-term outcomes to further inform clinical practice and enhance patient care.

The Cost-Effectiveness of Computer-Assisted Compared with Conventional Total Knee Arthroplasty: A Payer's Perspective.

Recent evidence showing that computer-assisted total knee arthroplasty (TKA) is associated with better outcomes compared with conventional TKA for patients with end-stage knee osteoarthritis has not been included in economic evaluations of computer-assisted TKA, which are needed to support coverage decisions. This study evaluated the cost-effectiveness of computer-assisted TKA from a payer's perspective, incorporating recent evidence. We compared computer-assisted TKA with conventional TKA with regard to costs (in 2022 U.S. dollars) and quality-adjusted life-years (QALYs) using Markov models for elderly patients (≥65 years of age) and patients who were not elderly (55 to 64 years of age). Costs and QALYs were estimated in the lifetime for elderly patients and in the short term for patients who were not elderly, under a bundled payment program and a Fee-for-Service program. Transition probabilities, costs, and QALYs were retrieved from the literature, a national knee arthroplasty registry, and the National Center for Health Statistics. Threshold and probabilistic sensitivity analyses were conducted to examine the robustness of key estimates used in the base-case analysis. Using projected estimates of TKA utilization, the total cost savings of performing computer-assisted TKA rather than conventional TKA were estimated. Compared with conventional TKA, computer-assisted TKA was associated with higher QALYs and lower costs for both elderly patients and patients who were not elderly, regardless of payment programs, making computer-assisted TKA a favorable treatment option. Widespread adoption of computer-assisted TKA in all U.S. patients would result in an estimated total cost saving of $1 billion for payers. Compared with conventional TKA, computer-assisted TKA reduces costs to payers while providing favorable outcomes. Payers may consider providing additional payment incentives to providers for performing computer-assisted TKA, to achieve outcome improvement and cost control by facilitating widespread adoption of computer-assisted TKA. Economic and Decision Analysis Level II. See Instructions for Authors for a complete description of levels of evidence.

The ROSA knee robotic system demonstrates superior precision in restoring joint line height and posterior condylar offset compared to conventional manual TKA: a retrospective case-control study.

Variations in total knee arthroplasty (TKA) joint line height may lead to complications such as pain and altered joint mechanics, while posterior condylar offset (PCO) can influence knee stability. Single-centre, single-surgeon retrospective analysis from December 2019 to May 2023 investigated primary unilateral TKA (Nexgen Legacy, Zimmer Biomet) in patients with knee osteoarthritis, using ROSA robotic system (raTKA) or conventional manual technique (mTKA). Joint line height and PCO were measured and compared in 182 raTKA and 144 mTKA patients. The groups were matched in age (p = 0.847) and sex distribution (p = 0.2). Excellent interobserver agreement (ICC ≥ 0.9). RaTKA mean joint line height difference was - 0.0001mm (± 3.48, 95% CI - 0.509, 0.509) (p = 0.523), - 0.951mm for mTKA (± 4.33, 95% CI - 1.664, - 0.237) (p = 0.009). RaTKA mean PCO difference was 0.52 mm (± 2.45, 95% CI 0.160, 0.880) (p = 0.005), 1.15mm for mTKA (± 4.01, 95% CI - 1.496, 1.818) (p < 0.001). Mean difference in joint line height of 0.95mm between groups was significant (p = 0.027), and for PCO, it was 0.63mm, demonstrating tendency towards significance (p = 0.08). Mean absolute value in joint line height difference between groups was not significant (p = 0.235) but highly significant for PCO (p < 0.001). The ROSA knee robotic system can more accurately restore joint line height and PCO compared to conventional manual TKA. The improved degree of precision raTKA offers may be a vehicle for better Patient-Reported Outcome Measures, but further correlational studies are required.

Robot-assisted knee arthroplasty: Analyzing the learning curve and initial institutional experience

Robot-assisted total knee arthroplasty (rTKA) involves a learning curve for orthopedic surgeons. The aim of the present study was to assess the surgical times of rTKA procedures performed by initial stage and proficiency stage surgeons in comparison with times of conventional total knee arthroplasty (cTKA). The results reveal that the learning curve for rTKA varies considerable between surgeons, suggesting that the skill and aptitude of the individual to adapt to the robotic system play key roles in the learning process. Proficiency stage surgeons were able to reduce rTKA surgical times to levels comparable with those of conventional surgeries after performing approximately 30 to 40 robotic procedures. Ongoing research has shown promising outcomes in terms of improved clinical results and reduced complications following the application of advanced robotic technology to total knee arthroplasty.

Appraisal of Clinical Improvement With Total Knee Arthroplasty in Valgus Knee Deformities: A Case Series.

Introduction This case series explores the efficacy of unassisted total knee arthroplasty (TKA) in addressing valgus knee deformity secondary to osteoarthritis. The study aims to evaluate functional outcomes pre- and post-surgery using the Knee Society Score (KSS) and radiological assessments in short-term follow-up. Six patients underwent TKA and were evaluated retrospectively. Statistical analysis revealed significant improvements in the angle of deformity, KSS, and range of motion postoperatively. The study underscores the success of TKA in correcting valgus deformity, improving knee function, and enhancing patient satisfaction. TKAis a highly successful treatment for osteoarthritis, providing functional recovery and improved quality of life. However, valgus knee deformity presents a challenge in TKA, affecting approximately 10% of patients. This study aims to assess the functional outcomes of TKA for valgus deformity using KSSand radiological evaluation in short-term follow-up. Materials and methods A retrospective observational study was conducted from November 2022 to December 2023, involving six patients with valgus knee deformity secondary to osteoarthritis. TKA was performed with no technological assistance, and patients were assessed pre- and post-surgery using KSS and radiological measurements. Statistical analysis was performed using paired t-tests. Case description Six patients with grade two valgus deformity underwent technology-unassisted TKA. The postoperative assessment revealed significant improvements in the tibiofemoral angle, KSS, and range of motion. The medial parapatellar approach for TKA was utilized with a standard unconstrained primary TKA prosthesis, resulting in successful correction of deformity and improved knee alignment. Discussion TKA is a widely performed and reliable surgical intervention, with valgus knee deformity posing specific challenges. This study demonstrates the effectiveness of conventional TKA in correcting valgus deformity, improving knee function, and enhancing patient satisfaction in a very small case series. Comparison with previous studies supports the findings of the pre-existing literature, highlighting the importance of appropriate surgical approach and patient selection. Conclusion TKAutilizing a medial parapatellar approach proved effective in our small case series in correcting valgus deformity, improving knee function, and enhancing patient satisfaction. Short-term follow-up reveals significant improvements in stability, posture, and KSS scores. Further assessments and longer-term follow-up are warranted to confirm the long-term effectiveness of this approach.

A Retrospective Study to Compare Patient Outcomes from Standard Total Knee Arthroplasty (TKA) versus Navigation-Guided Arthroplasty Using the Brainlab Software-Guided Surgical System at a Center in Hebei Province January 2021 to July 2023.

BACKGROUND This retrospective study aimed to compare patient outcomes from standard total knee arthroplasty (TKA) vs navigation-guided arthroplasty using the Brainlab software-guided surgical system at Cangzhou Hospital of Integrated TCM-WM, Hebei, Hebei Province, China from January 2021 to July 2023. MATERIAL AND METHODS A total of 239 patients who underwent total knee arthroplasty in Cangzhou Hospital of Integrated TCM-WM, Hebei from January 2021 to July 2023 were retrospectively analyzed. According to the inclusion criteria, 212 eligible patients were selected for analysis and divided into a Navigation Group (NG) (n=105) and a Traditional Group (TG) (n=107) according to surgical method used. Outcomes measured included duration of disease, operative time, intraoperative blood loss volume, postoperative length of hospital stay, and pain measured by the hospital for special surgery knee score (HSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and forgotten joint score (FJS). RESULTS The comparison of perioperative results between the 2 groups showed that the incision length in the NG was significantly longer than that in the TG (P<0.001, 95% Cl 2.59-3.35). At 3 months after surgery, the HSS score of the NG was statistically higher than that of the TG (P=0.002, 95% Cl 3.42-4.46); the WOMAC score of the NG was lower than that of the TG (P<0.001, 95% Cl -4.41-2.87); and the FJS score of the NG was significantly higher than that of the TG (P=0.003, 95% Cl 2.39-3.67). CONCLUSIONS Compared with conventional TKA, use of the Brainlab navigation system is associated with a longer incision, more accurate implantation position of the prosthesis, faster recovery of knee joint function, and helps patients to "forget" about their knee prosthesis in the short term.

Comparison of imageless robotic assisted total knee arthroplasty and conventional total knee arthroplasty: early clinical and radiological outcomes of 200 knees.

The aim of this study was to compare the short term clinical and radiological outcomes of imageless robotic and conventional total knee arthroplasty (TKA) and to estimate the accuracy of the two techniques by analysing the outliers after TKA. We have evaluated 200 consecutive knees (158 patients), 100 knees undergoing robotic TKA, and 100 knees treated with conventional TKA. Demographic parameters like age, gender, body mass index, diagnosis and range of motion were obtained. Knee society score (KSS) and Knee society functional score (KSS-F) were used for clinical evaluation. Mechanical alignment (Hip-knee-ankle angle), proximal tibial angle (MPTA), distal femoral angle (LDFA) and tibial slope were analysed for radiological results and outliers were compared between both groups. Outliers were defined when the measured angle exceeded ± 3° from the neutral alignment in each radiological measurement on the final follow-up radiograph.The minimum follow-up was 6months (range, 6 to 18months). The preoperative mean HKA angle was 169.7 ± 11.3° in robotic group and 169.3 ± 7.3° in conventional group. There was significant improvement in HKA, LDFA, MPTA and tibial slope compared to the preoperative values in both the groups (p < 0.01). The number of HKA, LDFA and tibial slope outliers were 31, 29 and 37, respectively, in the conventional group compared to 13, 23 and 17 in the robotic group (p < 0.01). There was a significant improvement in the KSS and KSS-F functional scores postoperatively in both the groups (p < 0.01). However, there was no significant difference in the functional scores between the groups postoperatively (p = 0.08). This study showed excellent improvement with both imageless robotic and conventional TKA, with similar clinical outcomes between both groups. However, radiologically robotic TKA showed better accuracy and consistency with fewer outliers compared with conventional TKA.

Associations of postoperative outcomes with geriatric nutritional risk index after conventional and robotic-assisted total knee arthroplasty: a randomized controlled trial.

The association between postoperative outcomes of robotic-assisted total knee arthroplasty (RA-TKA) and nutrition status among elderly adults remained unclear. The authors aimed to evaluate these associations and provide a nutrition status reference for the surgical technique selection of TKA. In the present study, the authors used data from a multicenter, prospective, randomized controlled project, which recruited patients underwent TKA therapy. A total of 88 elderly adults (age ≥65 years old) were included in this study. Their preoperative and postoperative demographic data and radiographic parameters were collected. Clinical outcomes, including postoperative hip-knee-ankle (HKA) angle deviation, knee society score (KSS), 10cm visual analog scale, and so on, were observed and compared between the RA-TKA group and the conventional TKA group. Logistic regression was performed to adjust several covariates. In addition, according to the results of restricted cubic splines analyses, all participants were categorized into two groups with GNRI≤100 and GNRI >100 for further subgroup analyses. Our results showed despite having a lower postoperative HKA angle deviation, the RA-TKA group had a similar postoperative KSS score compared with the conventional TKA group in elderly adults. Among elderly patients with GNRI>100, RA-TKA group achieved significantly more accurate alignment (HKA deviation, P =0.039), but did not obtain more advanced postoperative KSS scores because of the compensatory effect of good nutrition status. However, among elderly patients with GNRI≤100, RA-TKA group had significantly higher postoperative KSS scores compared to the conventional TKA group ( P =0.025) and this association were not altered after adjustment for other covariates. Considering the clinical outcomes of conventional TKA may be more susceptible to the impact of nutrition status, elderly patients with GNRI≤100 seem to be an applicable population for RA-TKA, which is more stable and would gain significantly more clinical benefits compared with conventional TKA.

Metal Ion Release in Cancer Patients Following Megaprosthesis Salvage Surgery

BackgroundMegaprostheses contain many more modular components than conventional total hip and knee arthroplasty, which may lead to higher serum levels of metal ions. The aim of this study was to determine serum concentrations of titanium, chromium, and cobalt ions in cancer patients after limb salvage surgery with a megaprosthesis. MethodsA retrospective, descriptive cohort analysis consisting of patients who underwent cancer-related limb salvage surgery with a megaprosthesis at our hospital between 2010 and 2020 was conducted. Baseline and follow-up data were extracted from clinical and surgical records. Blood samples were prospectively obtained. Descriptive statistics were used for the analysis. ResultsA total of 71 patients underwent limb salvage surgery during the study period. Of these, 22 (10 women, 12 men) were included in the study. The mean age was 52 years (range, 21 to 80). Most cases (n = 16; 72.7%) involved the femur. Most patients (n = 14, 63.6%) underwent total knee megaprosthesis surgery. Implant revision surgery was required in 45% of cases (n = 10), with a mean interval of 4.32 years between the initial and revision surgeries. The mean follow-up time after revision surgery was 4.05 years. High levels of chromium were observed in 22.7% of patients (n = 5). High cobalt levels were found in 68.2% (n = 15) of patients, with toxic levels in 9.1% (n = 2). Titanium levels were high in 77.3% (n = 17) of cases and toxic in 22.7% (n = 5). Postoperative chemotherapy was significantly associated with titanium levels (P = .017). No correlation was observed between metal ion levels and time from primary or revision surgery or time from the first to revision surgery. ConclusionsThis study shows that cancer-related limb salvage surgery with megaprosthesis is associated with metal ion levels that exceed established safe thresholds. Compared to conventional hip arthroplasty, a higher proportion of the patients in this cohort presented elevated levels of metal ions. Level of evidenceIII.

A commentary on "associations of postoperative outcomes with geriatric nutritional risk index after conventional and robotic-assisted total knee arthroplasty: a randomized controlled trial".

A commentary on "associations of postoperative outcomes with geriatric nutritional risk index after conventional and robotic-assisted total knee arthroplasty: a randomized controlled trial".

Comparison of Short-term Results: Robotic-assisted vs. Conventional Bilateral Total Knee Arthroplasty

Introduction: Robotic-assisted total knee arthroplasty is becoming widely accepted as a method to improve intra-operative measures and post-operative functional outcomes. While there is a large body of evidence supporting robotic-assisted unilateral total knee arthroplasty (TKA), few studies have examined the outcomes of this technology in simultaneous bilateral TKA procedures. Thus, the purpose of the study is to compare the clinical outcomes between patients undergoing simultaneous robot-assisted bilateral total knee arthroplasty (raTKA) versus conventional bilateral total knee arthroplasty (convTKA). Methods: We retrospectively reviewed 140 simultaneous bilateral TKA cases (61 conventional, 79 robot-assisted) performed by a single surgeon in a single institution from January 1, 2015 to December 11, 2020. The institution’s electronic medical records were reviewed for patient demographic information, operative data, and post-operative complications. Outcomes Based Electronic Research Database (OBERD) records were reviewed for patient-reported outcomes (Oxford Knee Score and SF-12 Version 1) preoperatively and postoperatively at 6 months, 1 year, and 2 years. Results: Both raTKA and convTKA groups exhibited clinically relevant improvements beyond the minimally clinically important difference (MCID) in SF-12 physical and Oxford Knee Scores at 6 months, 1 year, and 2 years post-surgery. There were no statistically significant differences found between the two groups in terms of postoperative SF-12 scores, Oxford Knee Scores, complications, or revision rates. The raTKA group had a longer length of stay (2.6 versus 2.2 days, P=0.001) and a significantly different discharge disposition with more patients entering acute rehab compared to the convTKA group (20 versus 7 patients respectively, P=0.031). Conclusion: Robotic-assisted total knee arthroplasty has a non-inferior impact on short-term patient outcomes compared to conventional methods in patients undergoing simultaneous bilateral total knee arthroplasty. Level of evidence: III

Outcomes following robotic assisted total knee arthroplasty compared to conventional total knee arthroplasty.

This study elaborates on previous research to compare length of stay, complication rates, and total cost between patients undergoing robotic assisted total knee arthroplasty (rTKA) and conventional total knee arthroplasty (cTKA). We hypothesized that patients undergoing rTKA would have reduced length of stay, lower complication rates, improved perioperative outcomes, and higher total healthcare costs than those undergoing cTKA. Data were collected from the National Inpatient Sample Database Healthcare Cost and Utilization Project between the years 2016-2019. Patients undergoing rTKA and cTKA were identified under International Classification of Diseases, 10th revision codes (ICD-10-CM/PCS). Length of stay, specific complications, and total costs were examined at time point. SPSS (v 27.0 8, IBM Corp. Armonk, NY) was utilized to compare demographic and analytical statistics between rTKA and cTKA. rTKA and cTKA were compared both before and after propensity matching. 17,249 rTKA (3.09%) and 541,122 cTKA (96.91%) were included. Compared to cTKA patients, rTKA patients had reduced average length of stay of 1.91 days (p < 0.001), higher average total cost of $67133.34 (p < 0.001), reduced periprosthetic infection (OR = 0.027, p < 0.001), periprosthetic dislocation (OR = 0.117, p < 0.001), periprosthetic mechanical complication (OR = 0.315, p < 0.001), pulmonary embolism (OR = 0.358, p < 0.001), transfusion (OR = 0.366, p < 0.001), pneumonia (OR = 0.468, p = 0.002), deep vein thrombosis (OR = 0.479, p = 0.001), and blood loss anemia (OR = 0.728, p < 0.001). These differences remained statistically significant even after propensity matching. This study supports our hypothesis that rTKA is associated with fewer complications, but higher average total cost than cTKA. Our study shows that rTKA can be safely performed in older and sicker patients. Future studies assessing the impacts of these findings on patient reported outcomes would provide further insight into the benefits of rTKA. Furthermore, identifying patient specific factors that place them at risk for increased complications with cTKA as opposed to rTKA could provide surgeons insight on the method of TKA that maximizes patient outcomes while minimizing healthcare cost.

Learning curve of Persona Partial Knee (PPK) arthroplasty: a clinical trial

BackgroundUnicompartmental knee arthroplasty (UKA) procedures are considered to be more technically demanding than conventional total knee arthroplasty (TKA), requiring a longer learning curve and more expert surgical skills. Despite some clear advantages of UKA over TKA (such as lesser blood loss, greater bone stock, greater knee performances, etc.), UKA evidenced a greater rate of revision.ObjectThis study investigated the learning curve of Persona Partial Knee (PPK) arthroplasty for primary medial UKA performed by a single, non-designer surgeon. PPK is a fixed-bearing, compartment-specific implant. The primary outcome of interest for this study was to evaluate the learning curve of the surgical duration. The secondary outcome of interest was to evaluate the learning curve of radiological implant positioning.MethodsPatients who underwent primary medial UKA using PPK (Zimmer-Biomet, Warsaw IN, USA) were prospectively enrolled for the study. All surgeries were performed by a single, non-designer surgeon experienced in knee and hip arthroplasty. The primary outcome of interest was to evaluate the surgical duration. The secondary outcome of interest was to evaluate the implant positioning. The learning curve was estimated using an appropriate nonlinear polynomial regression model with a lower Akaike Information Criterion (AIC).ResultsOne hundred twenty five patients were enrolled in the study. 59% of them (74 of 125 patients) were women. The patients’ mean age at the time of surgery was 70.1 ± 9.5 years and their mean body mass index (BMI) was 27.8 ± 4.2 kg/m2. Curve stabilisation of the surgical time was at the 94th patient, of the tibial angle at the 47th patient, of the tibial slope at the 54th patient, of the anterior protrusion at the 29th patient, and of the posterior protrusion at the 51st patient.ConclusionsThe learning curve for component positioning was achieved in approximately 50 cases. The curve of the surgical time achieved a plateau at 94 Persona Partial Knee. Additionally, the factors directly correlated with earlier stabilization of the learning curve in terms of component positioning were: male gender, younger age, right side, and larger components.

Variability of the femoral mechanical-anatomical axis angle and its implications in primary and revision total knee arthroplasty.

Distal femoral resection in conventional total knee arthroplasty (TKA) utilizes an intramedullary guide to determine coronal alignment, commonly planned for 5° of valgus. However, a standard 5° resection angle may contribute to malalignment in patients with variability in the femoral anatomical and mechanical axis angle. The purpose of the study was to leverage deep learning (DL) to measure the femoral mechanical-anatomical axis angle (FMAA) in a heterogeneous cohort. Patients with full-limb radiographs from the Osteoarthritis Initiative were included. A DL workflow was created to measure the FMAA and validated against human measurements. To reflect potential intramedullary guide placement during manual TKA, two different FMAAs were calculated either using a line approximating the entire diaphyseal shaft, and a line connecting the apex of the femoral intercondylar sulcus to the centre of the diaphysis. The proportion of FMAAs outside a range of 5.0° (SD 2.0°) was calculated for both definitions, and FMAA was compared using univariate analyses across sex, BMI, knee alignment, and femur length. The algorithm measured 1,078 radiographs at a rate of 12.6 s/image (2,156 unique measurements in 3.8 hours). There was no significant difference or bias between reader and algorithm measurements for the FMAA (p = 0.130 to 0.563). The FMAA was 6.3° (SD 1.0°; 25% outside range of 5.0° (SD 2.0°)) using definition one and 4.6° (SD 1.3°; 13% outside range of 5.0° (SD 2.0°)) using definition two. Differences between males and females were observed using definition two (males more valgus; p < 0.001). We developed a rapid and accurate DL tool to quantify the FMAA. Considerable variation with different measurement approaches for the FMAA supports that patient-specific anatomy and surgeon-dependent technique must be accounted for when correcting for the FMAA using an intramedullary guide. The angle between the mechanical and anatomical axes of the femur fell outside the range of 5.0° (SD 2.0°) for nearly a quarter of patients.