Traditional Total Knee Arthroplasty Research Articles

Computerized Versus Traditional Approaches for Total Knee Arthroplasty: A Quantitative Analysis of Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index.

Total knee arthroplasty (TKA) is a common surgery for osteoarthritis, with increasing prevalence expected in the near future. This systematic review and meta-analysis compared the effectiveness of computerized TKA versus traditional TKA, focusing on postoperative outcomes measured by the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and the Knee Society score (KSS). A search on PubMed and Cochrane databases on November 14, 2023 for retrospective randomized controlled trials (RCTs) yielded data on WOMAC and KSS. The search strategy was predefined, and methodological quality of studies was critically appraised. Two researchers extracted data. Unpaired t-testing assessed the mean monthly changes in KSS and WOMAC for computer-aided versus traditional TKA. Review Manager 5.3 was used for data synthesis and analysis. Out of 729 records, five RCTs enrolling 339 patients were eligible and analyzed using a random effects meta-analysis. The mean monthly ΔKSS score differed significantly between the traditional and computerized groups (11.47 ± 8.76 vs. 9.26 ± 6.05, respectively; p < 0.01). However, the pooled mean difference estimate showed no significant differences (D = 0.20, 95% CI = -0.53 to 0.93, p = 0.59), with high heterogeneity (I2 = 85%, p < 0.001). The mean monthly ΔWOMAC score also differed significantly (-14.18 ± 21.54 vs. -18.43 ± 20.65, respectively; p < 0.05), but again, no significant differences were found in the pooled estimate (D = 0.17, 95% CI = -0.46 to 0.79, p = 0.60), with moderate heterogeneity (I2 = 28%, p = 0.24).There is no significant difference in KSS or WOMAC outcomes between traditional and computerized TKA. The study suggests the need for further research with longer follow-up periods, more timepoints, and a broader range of patient outcome measures to fully evaluate the advantages and disadvantages of each method.

Improved postoperative kneeling ability in posterior stabilized total knee arthroplasty with medialized dome-patella resurfacing: A retrospective comparative outcome analysis

ObjectivesThis investigation aimed to evaluate if the modifications to prosthesis designs improve patients' clinical and functional outcomes after total knee arthroplasty (TKA), with a special focus on pain and kneeling ability. MethodsRetrospective and comparative analysis of consecutive patients who were treated with posterior stabilized TKA using two different prostheses designs (single surgeon, single vendor). Group 1 received a traditional design TKA (PFC Sigma; DePuy, Inc., Warsaw, IN) with conventional dome-patella resurfacing, and group 2 received a modern design implant (Attune; DePuy, Inc., Warsaw, IN) with medialized dome-patella resurfacing. Functional outcome (range of motion: ROM) and the Oxford Knee Score (OKS) were collected preoperatively, at 4–6 weeks and 12 months following surgery. ResultsNinety-nine participants were included. Of these, 30 received traditional-design implants and 69 received modern-design knee implants. The comparison between the two implants showed a statistically significant increase in total OKS and kneeling ability in the modern design cohort at 1-year follow-up compared to the traditional design cohort (p ​< ​0.01). In the modern design group, 53% (N ​= ​37) could kneel easily or with little difficulty, compared to 30% (N ​= ​9) in the traditional design group. No statistically significant differences in ROM or the OKS pain component were seen. ConclusionThe incorporation of a medialized dome-patella in modern knee implant design may offer advantages over traditional designs, as seen in improved total OKS and kneeling ability at one-year follow-up. Further research with larger cohorts is needed to confirm these findings and explore the broader impact of implant design changes on patient outcomes. Level of evidenceClinical Study, Level III.

Total Knee Arthroplasty in a Patient with Ipsilateral Painless Hip Arthrodesis: Technical Surgical Tips and a Novel Method for Intraoperative Navigation-Assisted Planning.

Total knee arthroplasty (TKA) in the setting of a previous ipsilateral hip fusion/arthrodesis is an uncommon and challenging procedure. There is little information available in the literature on the challenges and techniques available to perform TKA in these patients. For a traditional TKA procedure, the patient is placed in the supine position and various knee-positioning devices are used to allow for adequate knee and hip flexion, which is required for surgical exposure and tibia preparation. Ipsilateral hip arthrodesis presents two major challenges: (1) Hip flexion is crucial for adequate knee flexion while the patient is supine during the TKA procedure, and (2) the use of advanced technology, specifically computer navigation and robotic-assisted surgery techniques, is limited due to the inability to acquire the hip center of rotation during surgery, due to the lack of hip motion. Therefore, equipment and positioning must be adjusted by the surgeon to facilitate TKA in these patients. This article reports the case of a 72-year-old male patient with a long-standing, painless right hip arthrodesis, presenting with end-stage osteoarthritis of the right knee, leg-length discrepancy, and an 11.6° difference between the mechanical and anatomical axes of the femur. We describe the unique surgical planning as well as the surgical positioning options that allow for adequate knee flexion and proper surgical exposure. Furthermore, we describe a novel method of computer-assisted navigation for intra-operative planning and execution utilizing a reflected tibia as a template for the distal femoral cut.

Enhanced recovery after day surgery total knee arthroplasty, the new standard of care: An Asian perspective

BackgroundThis study describes the implementation of Enhanced Recovery After Surgery (ERAS) total knee arthroplasty (TKA) with day-surgery protocol to assess the outcome of ERAS day surgery TKA compared with traditional ERAS inpatient TKA in terms of length of stay (LOS), 30-day readmission, complications, and patient-reported outcome measures (PROMs). MethodsPatients who underwent unilateral primary TKA from August 2020 to July 2021 were followed up. All TKAs were performed with the ERAS protocol. Patients who fulfilled the following inclusion criteria were offered day-surgery protocol: (1) ASA ≤ 3; (2) agreeable for discharge home. In addition, this day-surgery protocol comprised the following: (i) on-call physiotherapy review; (ii) home visit by physiotherapist at 1 week postoperative; (iii) home visit by nurse at 2 weeks postoperative. Day surgery was defined as discharge within 24 h. Patients were followed up for 6 months and PROMs, postoperative complications, and re-admissions recorded. ResultsA total of 738 patients were included (342 ERAS day surgery, 396 ERAS inpatient). 92.4% of patients in the day-surgery group were successfully discharged within 24 h, leading to a shorter mean LOS of 1.13 days compared with 4.12 days in the inpatient group (P < 0.005). Both groups achieved significant and comparable improvement in Knee Society Score, Oxford Knee Score, and Physical and Mental component of Short Form-36. Both groups had similar rate of 30-day readmission and complications. ConclusionPatients who underwent ERAS day surgery TKA achieved similar functional and quality of life improvement compared with ERAS inpatient TKA with no increased complication rate. ERAS day surgery TKA is safe and cost effective, and its use should be promoted.

Robotic-assisted total knee arthroplasty in clinical practice: protocol for a randomised controlled trial

Between 2 and 20% of patients who undergo total knee arthroplasty (TKA) report restricted motion and anterior knee pain. Non-optimal alignment of the implant components is a common cause of such complaints. Robotic-assisted TKA has been advocated to improve the accuracy of component positioning to match patients’ anatomy and biomechanics. However, the advantages of robotic surgery over conventional freehand TKA are still unclear. The present study is a protocol for a single-blind clinical trial in which patients will be randomly allocated to undergo either robotic-assisted TKA or conventional freehand TKA. A restricted kinematic alignment with medial para-stellar approach shall be made in all patients. The present study follows the SPIRIT guidelines. The primary outcome of interest is to compare robotic TKA versus traditional freehand TKA in terms of patient-reported outcome measures (PROMs), length of hospitalisation, blood values, blood transfusion units, and range of motion. The second outcome of interest is to evaluate the accuracy of component positioning of robotic-assisted TKA compared to the conventional freehand TKA.Level of evidence Level I, randomised controlled trial.Registration German Registry of Clinical Trials (ID: DRKS00030614).

Obesity Severity Predicts Patient Dissatisfaction After Total Knee Arthroplasty

BackgroundPatient dissatisfaction has been reported in 15 to 20% of traditional total knee arthroplasty (TKA) procedures. While contemporary improvements may have positive effects on patient satisfaction, these may be offset by increasing obesity prevalence among patients who have knee osteoarthritis. We performed this study to determine whether obesity severity impacts patient-reported TKA satisfaction. MethodsWe compared patient demographic characteristics, preoperative expectations, preoperative and minimum 1-year postoperative patient-reported outcome measures as well as postoperative satisfaction level among 229 patients (243 TKAs) who had World Health Organization (WHO) Class II or III obesity (group A), and 287 patients (328 TKAs) who had WHO classifications of normal weight, overweight, or Class I obesity (group B). ResultsGroup A patients were younger and had more severe preoperative back and contralateral knee pain, more frequent preoperative opioid medication use, and lower preoperative and postoperative patient-reported outcome measures (P < .01). A similar proportion of patients in both groups expected at least 75% improvement (68.5 versus 73.2%, P = .27). While satisfaction was higher than traditional reporting for both groups (89.4 versus 92.6%, P = .19), group A patients were less likely to be highly satisfied (68.1 versus 78.5%, P = .04) and were more likely to be highly dissatisfied (5.1 versus 0.9%, P < .01). ConclusionsPatients who have Class II and III obesity report greater TKA dissatisfaction. Additional studies should help determine whether specific implant designs or surgical techniques may improve patient satisfaction or whether preoperative counseling should incorporate lower satisfaction expectations for patients who have WHO Class II or III obesity.

Transition to Robotic Total Knee Arthroplasty With Kinematic Alignment is Associated With a Short Learning Curve and Similar Acute-Period Functional Recoveries.

Background Robotic instruments are increasingly being used in total knee arthroplasty (TKA). The adoption of robotics has allowed surgeons a new level of precision and facilitated the adoption of a kinematic approach in TKA. We sought to examine one surgeon's transition from a traditional mechanical alignment technique to a modified kinematic approach by comparingshort-term recovery outcomes of robotic TKA patients with those who underwent traditionally instrumented TKAs. Methodology We examined six-week and six-month postoperative data from 99 traditionally instrumented, mechanically aligned and 66 kinematically aligned robotic TKA patients between January 2021-October 2021 and October 2021-April 2022, respectively. Robotic surgery was performed with VELYS™ (DePuy Synthes, Warsaw, IN, USA) a semi-active, imageless, table-affixed, robotic TKA solution. Results Robotic and traditionally instrumented TKAs did not differ significantly in any functional outcome measures examined, including pain scores, use of assistive devices, or range of motion at six weeks postoperatively. Robotic TKA patients had a better range of motion in knee flexion than traditional TKA patients at six months postoperatively. There were no differences in surgical complications or rates of manipulation under anesthesia within one year postoperatively. Robotic surgery tourniquet times exhibited a steep drop off and equaled traditional methods after only two robotic surgeries were performed. Conclusions Transition to a kinematic, semi-active, robotic TKA demonstrated encouraging results by demonstrating acute-period recovery of function consistent with the current standard of care, as well as a better range of motion at six months postoperatively. The learning curve of this new-to-market device was shorter than previous research on the transition to robotic TKA. Clear advantages of transitioning to robotic instrumentation by any specific functional measure are yet to be elucidated. Further randomized trials are necessary to characterize long-term outcomes.

A comparative study of short-term effectiveness of "SkyWalker" robot-assisted versus traditional total knee arthroplasty

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

Does a Uni "Feel Better" than a Total Knee? Not Necessarily, When Using Modern Implant Designs.

Background: When comparing functional outcomes of patients with unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA), studies often report the UKA as the preferred procedure; however, recent improvements in the design of modern TKA implants have aimed at narrowing this gap. Purpose: We sought to compare the "feel" of modern TKA implants to that of UKA, using the Forgotten Joint Score (FJS), a validated patient-reported outcome measure. Methods: We performed a retrospective review of patients who underwent TKA and UKA at 2 institutions between 2014 and 2017. All UKA procedures were robotic arm-assisted with a single implant, "traditional TKAs" were performed using traditional posterior-stabilized implants, and "modern TKAs" were performed using posterior-stabilized implants with a modern design. Differences in FJS were assessed using 1-way analysis of variance and independent 2-sample t tests. Results: A total of 600 patients were included in our study, with 200 patients in each surgical subcategory. Mean age was 62.8 ± 10.2 years and mean body mass index was 29.9 ± 4.9. Modern TKA and UKA had similar FJS at 1 year. While modern TKA had a significantly higher FJS than traditional TKA, UKA did not have a significantly higher FJS than traditional TKA. Conclusion: Our retrospective analysis found no significant differences in the FJS of patients who underwent UKA and TKA with a modern design; however, both had superior scores than traditional TKA designs. This finding suggests that modern TKA designs may have the potential to achieve the natural feeling that is typically associated with joint-conserving surgeries such as UKA, although longer follow-up is necessary.

Customized Individually-Made and Conventional Total Knee Implants are associated with Similar Improvements in Patient-Reported Outcomes

Background Customized individually-made (CIM) implants aim to reproduce knee kinematics by restoring patient-specific anatomy. There is sparse data comparing outcomes of CIM implants with conventional implants. The purpose of this study was to compare short-term outcomes of total knee arthroplasty (TKA) performed with CIM versus off-the-shelf (OTS) implants. Methods We retrospectively compared clinical outcomes of 123 CIM TKAs with 282 concurrent, matched OTS TKAs performed at a single academic medical center by two high-volume arthroplasty surgeons. All CIM TKA were included. Perioperative outcomes evaluated included hospital length-of-stay (LOS), discharge disposition, and patient-reported outcome measures (PROMs) at baseline, 3 months, and 1 year. Student’s t-tests were used for continuous variables, and chi-squared tests were used for categorical variables. Results Baseline demographics were statistically similar between groups. CIM Baseline WOMAC Pain and Physical Function scores were statistically, but not clinically, better. There were no differences in LOS (CIM 2.19d vs. OTS 2.35d; p=0.30) or proportion discharged home (78.7% vs. 83.5%, p=0.26). There were no differences in WOMAC subscores or the KSS Functional Score at 3-month and 1-year follow-up. The CIM cohort had a statistically significant, but not clinically significant, higher KSS-Function score at 1-year (79.4 vs. 72.6, p=0.02), but the change from preoperative baseline was not significant between groups. Conclusions Compared to traditional TKA implants, CIM implants offered similar improvements and patient-reported outcome scores through the first postoperative year. Longer-term outcomes as well as cost-effectiveness of CIM implants should be studied.

Computer-Navigated and Robotic-Assisted Total Knee Arthroplasty: Increasing in Popularity Without Increasing Complications

BackgroundData on the clinical impact of computer navigation (CN) and robotic assistance (RA) in total knee arthroplasty (TKA) are mixed. This study aims to describe modern utilization trends in CN-TKA, RA-TKA, and traditionally-instrumented (TD) TKA and to assess for differences in postoperative complications and opioid consumption by procedure type. MethodsA national database was queried to identify primary, elective TKA patients from 2015 to 2020. Trends in procedural utilization rates were assessed. Differences in 90-day postoperative complications and inpatient opioid consumption were assessed. Multivariate regression analyses were performed to account for potential confounders. ResultsOf the 847,496 patients included, 49,317 (5.82%) and 24,460 (2.89%) underwent CN-TKA and RA-TKA, respectively. CN-TKA utilization increased from 5.64% (2015) to 6.41% (2020) and RA-TKA utilization increased from 0.84% (2015) to 5.89% (2020). After adjusting for confounders, CN-TKA was associated with lower periprosthetic joint infection (P = .001), pulmonary embolism (P < .001), and acute respiratory failure (P = .015) risk compared to traditional (TD) TKA. RA-TKA was associated with lower deep vein thrombosis (P < .001), myocardial infarction (P = .013), and pulmonary embolism (P = .001) risk than TD-TKA. Lower postoperative day 1 opioid usage was seen with CN-TKA and RA-TKA than TD-TKA (P < .001). Lower postoperative day 0 opioid consumption was also seen in RA-TKA (P < .001). ConclusionFrom 2015 to 2020, there was a relative 13.7% and 601.2% increase in CN-TKAs and RA-TKAs, respectively. This trend was associated with reductions in hospitalization duration, postoperative complications, and opioid consumption. These data support the safety of RA-TKA and CN-TKA compared to TD-TKA. Further investigation into the specific indications for these technology-assisted TKAs is warranted.

Early effectiveness of computer navigation-assisted total knee arthroplasty

To estimate the early effectivenss of computer navigation-assisted total knee arthroplasty (TKA) by comparing with traditional TKA. The clinical data of 89 patients (100 knees) underwent primary TKA between October 2017 and July 2018 were analyzed retrospectively, including 44 patients (50 knees) who completed the TKA under the computer-assisted navigation system as the navigation group and 45 patients (50 knees) treated with traditional TKA as the control group. There was no significant difference between the two groups ( P>0.05) in gender, age, body mass index, diagnosis, side, disease duration, Kellgren-Lawrence classification of osteoarthritis, and preoperative American Hospital for Special Surgery (HSS) score, range of motion (ROM), hip-knee-ankle angle (HKA) deviation. The operation time, incision length, difference in hemoglobin before and after operation, postoperative hospital stay, and the complications were recorded and compared between the two groups. The HSS score, ROM, and joint forgetting score (FJS-12) were used to evaluate knee joint function in all patients. Unilateral patients also underwent postoperative time of up and go test and short physical performance battery (SPPB) test. At 1 day after operation, the HKA, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), sagittal femoral component angle (sFCA), and sagittal tibial component angle (sTCA) were measured and calculated the difference between the above index and the target value (deviation); and the joint line convergence angle (JLCA) was also measured. The operations of the two groups were successfully completed, and the incisions healed by first intention. The operation time and incision length of the navigation group were longer than those of the control group ( P<0.05); the difference in difference of hemoglobin before and after the operation and the postoperative hospital stay between groups was not significant ( P>0.05). Patients in the two groups were followed up 27-40 months, with an average of 33.6 months. Posterior tibial vein thrombosis occurred in 1 case in each of the two groups, and 1 case in the control group experienced repeated knee joint swelling. The HSS scores of the two groups gradually increased after operation ( P<0.05); HSS scores in the navigation group at 1 and 2 years after operation, and knee ROM and FJS-12 scores at 2 years were significantly higher than those in the control group ( P<0.05). There was no significant difference in the postoperative time of up and go test and SPPB results between the two groups at 7 days after operation ( P>0.05); the postoperative time of up and go test of the navigation group was shorter than that of the control group at 2 years ( t=-2.226, P=0.029), but there was no significant difference in SPPB ( t=0.429, P=0.669). X-ray film measurement at 1 day after operation showed that the deviation of HKA after TKA in the navigation group was smaller than that of the control group ( t=-7.392, P=0.000); among them, the HKA deviations of 50 knees (100%) in the navigation group and 36 knees (72%) in the control group were less than 3°, showing significant difference between the two groups ( χ 2=16.279, P=0.000). The JLCA and the deviations of mLDFA, mMPTA, sFCA, and sTCA in the navigation group were smaller than those in the control group ( P<0.05). Compared with traditional TKA, computer navigation-assisted TKA can obtain more accurate prosthesis implantation position and lower limb force line and better early effectiveness. But there is a certain learning curve, and the operation time and incision length would be extended in the early stage of technology application.

Application and research progress of robotic-arm in total knee arthroplasty

To summarize the application and research progress of robotic-arm in total knee arthroplasty (TKA). Relevant literature at home and abroad was extensively reviewed to analyze the advantages and disadvantages of robotic-arm assisted TKA (RATKA). Accurate reconstruction of lower extremity alignment and rotation alignment, accurate osteotomy and implant prosthesis in TKA are very important to improve the effectiveness and prolong the life of the prosthesis. Traditional TKA deviations occur in key links such as osteotomy due to operator's operation. RATKA solves the above problems to a certain extent and can assist accurate osteotomy and implant prosthesis, and protect the soft tissues around the knee joint. Patients' satisfaction after RATKA is high, and the operator's learning curve is shorter, which improves the efficiency of the operation. But it also has disadvantages such as prolonged operation time, increased complications and medical costs. Preliminary clinical application studies have shown that RATKA has satisfactory effectiveness, but its definite advantages compared with traditional TKA need to be confirmed by a large number of randomized controlled trials and long-term follow-up.

Robotic total knee arthroplasty: A missed opportunity for cost savings in Bundled Payment for Care Improvement initiatives?

BackgroundThe use of robotic total knee arthroplasty has become increasingly prevalent. Proponents of robotic total knee arthroplasty tout its potential to not only improve outcomes, but also to reduce costs compared with traditional total knee arthroplasty. Despite its potential to deliver on the value proposition, whether robotic total knee arthroplasty has led to improved outcomes and cost savings within Medicare’s Bundled Payment for Care Improvement initiative remains unexplored. MethodsMedicare beneficiaries who underwent total knee arthroplasty designated under Medicare severity diagnosis related group 469 or 470 in the year 2017 were identified using the 100% Medicare Inpatient Standard Analytic Files. Hospitals participating in the Bundled Payment for Care Improvement were identified using the Bundled Payment for Care Improvement analytic file. We calculated risk-adjusted, price-standardized payments for the surgical episode from admission through 90-days postdischarge. Outcomes, utilization, and spending were assessed relative to variation between robotic and traditional total knee arthroplasty. ResultsOverall, 198,371 patients underwent total knee arthroplasty (traditional total knee arthroplasty: n= 194,020, 97.8% versus robotic total knee arthroplasty: n = 4,351, 2.2%). Among the 3,272 hospitals that performed total knee arthroplasty, only 300 (9.3%) performed robotic total knee arthroplasty. Among the 183 participating in the Bundled Payment for Care Improvement, only 40 (19%) hospitals performed robotic total knee arthroplasty. Risk-adjusted 90-day episode spending was $14,263 (95% confidence interval $14,231–$14,294) among patients who underwent traditional total knee arthroplasty versus $13,676 (95% confidence interval $13,467–$13,885) among patients who had robotic total knee arthroplasty. Patients who underwent robotic total knee arthroplasty had a shorter length of stay (traditional total knee arthroplasty: 2.3 days, 95% confidence interval: 2.3–2.3 versus robotic total knee arthroplasty: 1.9 days, 95% confidence interval: 1.9–2.0), as well as a lower incidence of complications (traditional total knee arthroplasty: 3.3%, 95% confidence interval: 3.2–3.3 versus robotic total knee arthroplasty: 2.7%, 95% confidence interval: 2.3–3.1). Of note, patients who underwent robotic total knee arthroplasty were less often discharged to a postacute care facility than patients who underwent traditional total knee arthroplasty (traditional total knee arthroplasty: 32.4%, 95% confidence interval: 32.3–32.5 versus robotic total knee arthroplasty: 16.8%, 95% confidence interval 16.1–17.6). Both Bundled Payment for Care Improvement and non-Bundled Payment for Care Improvement hospitals with greater than 50% robotic total knee arthroplasty utilization had lower spending per episode of care versus spending at hospitals with less than 50% robotic total knee arthroplasty utilization. ConclusionOverall 90-day episode spending for robotic total knee arthroplasty was lower than traditional total knee arthroplasty (Δ $–587, 95% confidence interval: $–798 to $–375). The decrease in spending was attributable to shorter length of stay, fewer complications, as well as lower utilization of postacute care facility. The cost savings associated with robotic total knee arthroplasty was only realized when robotic total knee arthroplasty volume surpassed 50% of all total knee arthroplasty volume. Hospitals participating in the Bundled Payment for Care Improvement may experience cost-saving with increased utilization of robotic total knee arthroplasty.

Short-Term Outcomes Are Comparable between Robotic-Arm Assisted and Traditional Total Knee Arthroplasty.

Robotic-arm assisted total knee arthroplasty (rTKA) was developed to provide for increased accuracy of component placement compared with conventional manual TKA (mTKA). Whether or not rTKA is cost-effective in a bundled payment model has yet to be addressed. The purpose of this comparative study was to evaluate the short-term clinical outcomes of rTKA and mTKA. We retrospectively reviewed a series of 4,086 consecutive primary TKA performed by one of five surgeons across six different hospitals at our institution from January 2016 to December 2018. Outcomes for rTKA cases (n = 581) and mTKA cases (n = 3,505) were compared using unmatched multivariate analysis and a matched cohort. We analyzed 90-day outcomes, episode-of-care claims data, and short form (SF-12) outcome scores to 2 years postoperatively. In matched bivariate analysis, there was no difference in episode-of-care costs, postacute care costs, complications, 90-day readmission rates, emergency department/urgent care visits, reoperations, and mortality between rTKA and mTKA patients (p > 0.05). Matched patients undergoing rTKA did have a shorter hospital length of stay (1.46 vs. 1.80 days, p < 0.001) and decreased rates of discharge to rehabilitation facilities (5.5 vs. 14.8%, p < 0.001). SF-12 scores were clinically similar. Multivariate analysis demonstrated no differences in any 90-day outcome. We conclude that patients undergoing rTKA have comparable costs, 90-day outcomes, and clinically similar improvements in functional outcome scores compared with mTKA patients. Further study is needed to determine whether rTKA will result in improved implant survivorship and long-term functional outcomes (Level of evidence III).

Hospital Discharge Within a Day After Total Knee Arthroplasty Does Not Affect 1-Year Complications Compared With Rapid Discharge.

In patients undergoing total knee arthroplasty (TKA), it is unclear whether a difference in complication rates exists between patients discharged the day of surgery compared with subsequent postoperative days. Data were collected from the PearlDiver Patient Records Database from 2007 to 2017. Subjects were identified using International Classification of Diseases codes. Eligible patients were stratified into the following three groups: (1) same day discharge (<24 hours postoperatively), (2) rapid discharge (1 to 2 days), and (3) traditional discharge (3 to 4 days) based on the length of stay. In total, 84,864 patients were identified as having undergone primary TKA. The incidence of same day discharge, rapid discharge, and traditional discharge was 2.36% (2,004/84,864), 28.56% (24,235/84,864), and 69.08% (58,625/84,864), respectively. After adjustment, no notable differences were observed in the overall complication and revision rates between the same day discharge group and either the rapid discharge or the traditional discharge group. On multivariate analysis, patients in the rapid discharge cohort were less likely to require manipulation under anesthesia or develop periprosthetic joint infection when compared with the traditional discharge group at 1 year postoperatively. For those who qualify after careful selection, same day and rapid discharge TKA may be a feasible alternative to the traditional inpatient TKA. A level 3 retrospective, prognostic study.

A Comparison Of Gait Biomechanics And Clinical Outcomes Between Traditional And Robot-Assisted Total Knee Arthroplasty

More than 600,000 knee replacements are performed each year in the U.S. for patients with knee osteoarthritis (OA), a rate expected to rise as high as 3 million by 2030. However, mechanical axis malalignment during total knee arthroplasty (TKA) has been found in almost one-third of surgeries. Recent advances in surgical technology include the use of robots to improve implant precision, including the Mako Robotic-Arm Assisted System, with the goal of improving clinical outcomes and gait biomechanics. PURPOSE: To compare gait biomechanics and clinical outcomes between patients who underwent TKA with the Mako System (MAKO) and patients who underwent traditional TKA (TRAD), as well as to healthy participants. METHODS: Gait biomechanics were collected on female participants (6 MAKO, 7 TRAD, 16 HEALTHY limbs; age: 50-80 years) using an 8-camera Vicon motion capture system and two force plates. The Forgotten Joint Score (FJS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) surveys were collected on all TKA participants. One-way ANOVAs compared biomechanics between participants, while unpaired t-tests compared survey data between surgical groups. Effect sizes (ES) were calculated using Cohen’s d. RESULTS: Both surgical groups exhibited lower hip extension excursion (MAKO: 23.9 ± 3.8°, TRAD: 24.0 ± 5.4°, HEALTHY: 32.7 ± 8.0°, p = 0.008, ES = 1.41). The external knee varus moment was trending lower for the MAKO group compared to the HEALTHY and TRAD groups with a large effect size (MAKO: .33 ± .17 Nm/kg, TRAD: .44 ± .09 Nm/kg, HEALTHY: .49 ± .14 Nm/kg, p = .051, ES = 1.15). No differences were seen in survey scores between groups, but a large effect size was observed for the FJS (MAKO: 68.8 ± 21.9, TRAD: 50.5 ± 23.6, p = 0.17, ES = 0.80). CONCLUSIONS: TKA participants exhibited limited hip extension excursion, which may indicate compromised gait stability compared to healthy participants. The external knee varus moment was trending lower in Mako participants compared to traditional TKA and healthy participants. Because elevated knee varus moments have been correlated with pain and disease progression in knee OA, this finding indicates the Mako procedure may lower a major correlate of disease. Mako participants had higher FJS scores, which indicates they are less aware of their artificial joint. No grant support was provided.

Établissement et validation d’un modèle de facteurs de risque d’infection d’une mégaprothèse autour du genou après résection d’une tumeur osseuse

BackgroundDue to the particularity of patients with bone tumors, the risk of periprosthetic infection following megaprosthetic replacement is much higher than that of traditional total knee arthroplasty. Unfortunately, few studies specifically reported the risk factors for periprosthetic infection following megaprosthetic replacement. The purposes of the study were to (1) establish a nomogram model which can provide a reference for clinicians and patients to reduce the occurrence of periprosthetic infection; (2) explore the risk factors for deep infection of megaprosthesis. HypothesisA prediction model can be established and has favorable predictive accuracy. Patients and methodsOne hundred and seventy-seven megaprostheses were identified. There were 61 female patients and 116 male patients with a mean age of 35 years. The following risk factors were analyzed: tumor site, sex, age, material for prosthetic stem, tumor type, smoking, diabetes, length of bone resection, operation time, chemotherapy, BMI, malignant tumor staging and hematoma formation. Finally, based on the multivariate analysis, the independent risk factors were used to develop a nomogram model. ResultsUnivariate Cox regression analysis showed that the chemotherapy, longer operation time and hematoma formation were risk factors for periprosthetic infection. Multivariate Cox regression analysis showed that the chemotherapy, longer operation time and hematoma formation were significant risk factors for periprosthetic infection. The nomogram model was established using these significant risk factors, with a C-index of 0.766 and an acceptable consistency according to the internal validation, indicating that the prediction model had favorable predictive accuracy. DiscussionThis study has important implications for the future investigations of prevention of periprosthetic infection. The nomogram model identifies high-risk patients for whom attached prophylaxis measures are required. Future studies regarding reduction of incidence of periprosthetic infection should pay close attention to these high-risk patients. Level of evidenceIV, retrospective, cohort study.

Evaluation of the Medial Stabilized Knee Design Using Data From National Joint Registries and Current Literature

BackgroundVarious designs of total knee arthroplasty (TKA) have provided satisfactory outcomes for the treatment of knee osteoarthritis for many years. The aim of the study is to evaluate the success and failure rate of the medial stabilized (MS) TKA design through national joint registries and the current literature. Materials and MethodsA comprehensive literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was carried out through PubMed and MEDLINE database. The international registries analyzed included the National Joint Registry, the Australian Orthopedic Association National Joint Replacement Registry, the Dutch Arthroplasty Register, the New Zealand Orthopedic Association Joint Registry, and the Michigan Arthroplasty Registry Collaborative Quality Initiative. We are reporting descriptive data which include means and percentages of survival rates and revision rates and number of years after the primary procedure. The revision rates and the cumulative revision rates are reported separately for each MS implant. ResultsOur detailed review identified 5 of 12 registries and 25 of 550 studies reporting on the survivorship of an MS TKA design. There were a total of 3684 procedures between the 25 studies, with an average survivorship free of aseptic loosening of 99% at 6.9 years. There are 26,693 (2.5%) MS TKAs in the current National Joint Registry with a mean cumulative revision rate of 2.63% at 5 years, 3.35% at 10 years, and 4.6% at 15 years. The Australian Orthopedic Association National Joint Replacement Registry provides survivorship data on 19,249 (2.9%) MS TKAs, with a mean cumulative revision rate of 3.34% at 5 years, 7.4% at 10 years, and 8.1% at 15 years. The Dutch Arthroplasty Register contains survivorship data on 1490 MS designs and a mean revision rate of these implants is 0.8% at 1 year, 5.95% at 5 years, and 9.8% at 10 years. The Evolution MP is the only implant reported in the Michigan Arthroplasty Registry Collaborative Quality Initiative and has a revision rate of 2.28% at 3 years. ConclusionThe MS TKA design has comparable results to traditional TKA designs across several joint registries and 25 studies in the literature.

Effect of total knee arthroplasty under computer navigation on intraoperative blood loss and joint function recovery

To analyze the effect of computer navigation assisted total knee arthroplasty on intraoperative hemorrhage and postoperative joint function recovery in patients with knee osteoarthritis. From February 2015 to December 2017, 65 patients with knee osteoarthritis treated by traditional total knee arthroplasty were retrospectively analyzed as the control group and 65 patients with knee osteoarthritis treated by total knee arthroplasty under computer navigation as the experimental group. Before operation, all patients showed red swelling pain of knee, pain of going up and down stairs, and pain and discomfort of waist when sitting up and standing up. All patients were treated with total knee arthroplasty. The control group was treated with traditional total knee arthroplasty, and the experimental group was treated with total knee arthroplasty under the computer navigation system. The operation related conditions of the two groups were recorded and compared including the operation time and hospitalization time; the changes of hemoglobin and hematocrit of the two groups were detected and compared before and 5 days after the operation; the blood loss of the two groups and the induced flow at each time point calculated and compared after the operation, and the perioperative allogeneic blood transfusion rate and average blood transfusion volume of the patients were recorded; The joint function scale (KSS) was used to evaluate the recovery of knee joint function before the operation, 6 and 18 months after the operation respectively and to record the incidence of postoperative infection, lower extremity venous thrombosis and other complications. All the patients were successfully operated and the prognosis of the wound was good. All the patients were followed up for an average of 18 months. The operation time of the experimental group was longer than that of the control group, and the hospitalization time was shorter than that of the control group (P <0.05) ; the KSS score of the two groups at each time point after operation was higher than that before operation, but the increasing range of the test group was higher than that of the control group (P<0.05) ; there was no significant difference between the two groups in the incidence of complications (P>0.05) . Under the guidance of computer navigation, total knee arthroplasty can prolong the operation time compared with single total knee arthroplasty, but it is more conducive to reduce perioperative blood loss, reduce the rate of postoperative allogeneic blood transfusion, ideal recovery of joint function, less complications, safety and reliability.