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Bicruciate-stabilized (BCS) total knee arthroplasty (TKA) designs attempt to approximate natural knee mechanics. Multiple surgical techniques, including gap balancing (GB) and measured resection (MR), have been developed to provide optimal implant positioning and soft-tissue balance. The goal of this study was to determine the effect of surgical technique on BCS TKA contact kinematics. Secondary goals included investigating the change of kinematics over time and comparing BCS TKA kinematics to a posterior-stabilized (PS) design. The study included the BCS-GB, BCS-MR, and PS-MR groups. The BCS-GB and BCS-MR groups underwent weight-bearing radiostereometric analysis for multiple knee flexion angles at 3 months and 1 year postoperatively, whereas the PS-MR group was imaged at 1 year postoperatively. The medial and lateral contact kinematics were determined from implant poses. There were no differences in BCS TKA kinematics between the GB and MR techniques. There were differences in the mid-flexion ranges when comparing the 3-month and 1-year kinematics of the BCS design; however, they were less than 1.5 mm. Differences existed between the kinematics of the BCS and PS designs at all flexion angles for the medial condyle (P <.0006) and at 0° of flexion on the lateral condyle (P <.0001). Contact kinematics for a BCS design were similar for both surgical techniques, suggesting both are appropriate for this design. Small, likely clinically insignificant differences were found between 3-month and 1-year kinematics. The BCS TKA kinematics differed from the PS design; however, it is unclear whether these differences improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Contact kinematics in total knee arthroplasty (TKA) has been shown to affect tibial component migration. However, previous studies correlating kinematic variables to implant migration were completed with older TKA designs. The goal of this study was to determine if there are associations between contact kinematics and tibial component migration for a cemented, bicruciate stabilized (BCS) TKA system. A total of 54 knees implanted with a BCS TKA system were analyzed using radiostereometric analysis (RSA). Patients underwent RSA exams at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years post operation to measure tibial component migration. At 1 year, contact kinematics was evaluated during a quasi-static deep knee bend. Linear regression analyses were performed between kinematic variables and migration values. Significant correlations were found between contact kinematics and tibial component migration. Excursion on the lateral condyle was the most consistent variable correlating with implant migration. Six patients had > 0.2 mm migrations from 1 to 2 years post operation indicating continuously migrating tibial components, and most had atypical contact kinematics. Kinematics was shown to influence tibial component migration. Reduced lateral excursion, suggesting a more constrained lateral condyle, resulted in greater implant migration. The 6 patients who had continuously migrating tibial components had demographic factors that may limit the ability to endure unintended force transmissions caused by abnormal kinematics. These results highlight the importance of restoring knee kinematics with this BCS TKA design to minimize improper force transmissions and resultant increased implant migrations. [ABSTRACT FROM AUTHOR]

Background: The prevalence and outcomes of unexpected positive intraoperative cultures (UPC) in presumed aseptic revision total knee arthroplasty (TKA) are unclear. The purpose of this study was to determine the prevalence of UPC and infection-free implant survival in this patient population. Secondly, we aimed to compare the infection-free implant survival between cohorts based on number of UPCs and antibiotic treatment.Methods: We reviewed our institutional database from 2006 to 2019 for all TKA revisions (n = 1795) to identify all presumed aseptic TKA revisions with intraoperative culture(s). After exclusions, 775 revisions were eligible and those with UPC were included in the Kaplan-Meier analysis to determine infection-free implant survival for the cohorts.Results: The prevalence of UPC was 9.8%. The 2- and 5-year infection-free survival was 97.4% and 95.3%, respectively. The 5-year infection-free survival from the same microorganism as the UPC was 98.7%. Infection-free survival was similar for the 1 versus ≥2 UPC cohorts (P = .416), however was poorer for the cohort treated with antibiotics (P = .021). Only one of 3 subsequent PJI-related implant failures was caused by the same microorganism (polymicrobial) as the UPC. There were no subsequent infections in patients with a single UPC not treated with antibiotics.Conclusions: The prevalence of UPC was 9.8% and the infection-free implant survival is excellent. Infection-free survivorship from PJI caused by the same UPC microorganism is outstanding. Comparisons between cohorts must be interpreted with caution due to study limitations. A single UPC in patents without other signs of infection does not require antibiotic treatment.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Background: Implant migration and altered kinematics have been thought to impact patient-reported outcome measures (PROMs) and postoperative patient satisfaction. In this study comparing satisfied and dissatisfied total knee arthroplasty (TKA) patients, we hypothesized that dissatisfied patients will have greater continuous implant migration and that there will be differences in joint kinematics, objective functional measurements, and PROMs between satisfied and dissatisfied patients.Methods: The Knee Society Score Satisfaction Subsection questions regarding satisfaction with function were used at least 6 months postoperation to split 50 patients into satisfied and dissatisfied groups. Patients underwent radiostereometric analysis to evaluate migration and kinematics. A wearable sensor system obtained objective measurements of patient function during timed up and go tests. PROMs were recorded preoperation and postoperation.Results: No statistically significant differences were found in migration between satisfied and dissatisfied groups. Statistical kinematic differences existed in lateral anteroposterior contact location at 20° and 40° of flexion at 1 year, where the dissatisfied group had more anteriorly located lateral contact. No statistically significant differences were present in objective functional measurements. Satisfied and dissatisfied groups had differing PROMs at 4 timepoints or greater for each questionnaire.Conclusions: No differences were found in tibial component migration or objectively measured function between satisfied and dissatisfied patients. Functionally dissatisfied patients had more anteriorly positioned contact on the lateral condyle in early flexion and reported more pain and unmet expectations. These findings suggest that improving the functional satisfaction of TKA requires restoration of kinematics in early flexion and management of patient's pain and expectations. [ABSTRACT FROM AUTHOR]

Background: The goal of this study is to investigate the migration and inducible displacement of a bicruciate-stabilized (BCS) total knee arthroplasty implanted using gap balancing (GB) or measured resection (MR) surgical techniques. We hypothesized equal migration and displacement between the techniques.Methods: The study is a single-blinded, prospective, randomized controlled trial, with allocation of 71 patients to either GB or MR groups. Fifteen patients were withdrawn, resulting in 31 patients in the GB group and 25 in the MR group. Patients received the JOURNEY II™ BCS implant. Migration and inducible displacement were evaluated using radiostereometric analysis and patient examinations were performed at a 2-week baseline, and at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperation.Results: No differences (P > .05) existed between GB and MR groups for any measurement of tibial or femoral migration. Both groups had tibial migrations below 0.5 mm from baseline to 6 months, and below 0.2 mm from both 6 months to 1 year and 1-2 years postoperation. No differences (P > .05) were found between GB and MR groups for inducible displacement.Conclusion: No differences were found in implant migration or inducible displacement between GB and MR groups. The BCS implant can be expected to have migration risks on par with industry standards and both surgical techniques are safe and effective options for implantation of this implant design. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify the rate and risk factors for revision total knee arthroplasty (TKA) within the first 5 years postoperative. Our secondary objective was to identify the rate of additional surgical procedures and death. We conducted a retrospective cohort study among patients in Ontario, Canada who underwent an elective, primary TKA between April 1, 2007, and March 31, 2014, for osteoarthritis. We excluded patients under 40 years and who had undergone a TKA within the previous 15 years. Our final study cohort included 94,193 patients. We reported the proportion of the study cohort who experienced revision surgery within 2 and 5 years of the primary TKA; secondary surgery within 5 years. We conducted Cochran-Armitage tests for trends to assess changes in the proportion of patients who experienced each of the study outcomes, and multivariable logistic regressions to evaluate predictors of a revision TKA. There were 3,112 (3.3%) patients who had a revision within 5 years, and 1,866 (2.0%) within 2 years of their primary TKA. 3,316 (3.5%) had a secondary surgery (0.6% patellar resurfacing; 1.6% manipulation; 1.3% synovectomy; 0.5% washout; 0.9% debridement). Lower age, men, lower income, higher comorbidity score, depression, previous arthroscopy, lower surgeon volume, and general anesthesia were all significant positive predictors of revision. In our study cohort, 2.0% of patients had a revision TKA within 2 years, and 3.3% within 5 years of their primary TKA. Preoperative identification of risk factors may reduce the future prevalence of revision TKAs. [ABSTRACT FROM AUTHOR]

Background: Several treatment modalities exist for the treatment of perioperative anemia. We determined the effect of oral iron supplementation on preoperative anemia, and the use of blood-conserving interventions before total hip arthroplasty (THA) and total knee arthroplasty (TKA).Methods: A total of 3435 total joint arthroplasties (1461 THAs and 1974 TKAs) were analyzed during 2 phases of a blood conservation program. The first phase used erythropoietin alfa (EPO) or intravenous (IV) iron for patients at risk for perioperative anemia. The second phase included these interventions, as well as preoperative iron supplementation. The effect on preoperative hemoglobin (Hb) and serum ferritin, as well as EPO and IV iron utilization, was determined.Results: Oral iron therapy increased preoperative Hb level by 6 g/L (P < .001) and 7 g/L (P < .001) in the hip and knee cohorts, respectively. Serum ferritin level rose by 80 μg/L (P < .001) and 52 μg/L (P < .001) in the hip and knee cohorts, respectively. The number of patients with an Hb level <130 g/L was significantly reduced (P < .001 for both cohorts), as were patients with serum ferritin levels <35 μg/L (P = .002 for hip and P < .001 for knee cohorts). Utilization of EPO reduced from 16% to 6% (P < .001) and 18% to 6% (P < .001) in the hip and knee cohorts, respectively. Utilization of IV iron reduced from 4% to 2% (P = .05) and 5% to 2% (P < .001) in the hip and knee cohorts, respectively.Conclusion: Oral iron therapy reduced the burden of perioperative anemia and reduced utilization of other blood-conserving therapies before THA and TKA. Future research should delineate the cost-effectiveness of oral iron therapy. [ABSTRACT FROM AUTHOR]

Background: Coronal plane alignment is one of the contributing factors to polyethylene wear in total knee arthroplasty.Methods: Based on 95 retrieved polyethylene inserts, wear and damage patterns were analyzed in relationship to the overall mechanical alignment and to the position of the tibial component.Results: A progression of wear was observed with progressively mechanical varus alignment. However, there was significantly more damage in the lateral compartment in the mild and moderate varus group compared to the valgus group. No difference in damage was seen between all groups for tibial component positioning in valgus or varus.Conclusion: Progressive wear was observed with progressively varus alignment with more damage at the lateral side. This observation is unique and might be explained by lateral condylar lift-off inducing impact and shear loading in the varus group. [ABSTRACT FROM AUTHOR]

Current discussion exists whether to position a total knee arthroplasty (TKA) in slight undercorrection in varus osteoarthritis. The goal of this study was to analyse the effect of wear and lateral lift-off in primary TKA on coronal plane alignment and the implication to future constrained revision TKA. Seventy-six retrieved tibial inserts were analysed for the ratio of wear (RW), lateral lift-off and implications for future constrained revision surgery according to the coronal plane alignment. The RW significantly affects the coronal plane alignment in TKA. Progressive wear and lateral lift-off were seen with progressive varus alignment. However, there was no difference in constrained revision between mild varus and moderate varus aligned TKAs. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to determine agreement between responses on electronic and paper versions of the WOMAC and SF-12(v2) questionnaires following total hip and total knee arthroplasty. Patients completed both electronic and paper questionnaires with a one week interval in-between. The order in which they completed the two versions was randomly assigned. A total of 53 patients completed the study, with a mean age of 69years (range 50–90years). The intraclass correlation coefficients (ICC) were high, indicating excellent agreement (WOMAC ICC=0.96, 95% CI 0.94–0.98), SF-12 (PCS) ICC=0.95, 95% CI 0.92–0.97; SF-12 (MCS) ICC=0.92, 95%CI 0.86–0.95). Online data collection may be substituted for the traditional paper method with no significant effect on the criterion validity of the questionnaires. [Copyright &y& Elsevier]

Abstract: Geometric wear analysis techniques require unworn geometries to serve as a reference in wear measurement. A method to create a reference geometrical model is described for retrieval studies when the actual unworn geometry is unavailable. Never-implanted tibial inserts were scanned with micro–computed tomography. Two, 3, or 6 insert surfaces were coaligned and averaged to create reference geometries. Individual inserts were compared with each other (manufacturing variability) and with the reference geometries (reference variability). The 3-dimensional deviations between the surfaces were recorded. The reference variability was reduced to 8.3 ± 39 μm, vs manufacturing variability of 15 ± 59 μm. Deviations were smallest on the articular surfaces where most wear occurs and were significantly less than the reported insert wear rate of 20 μm/y. [Copyright &y& Elsevier]

Abstract: Three cases of a dislocated polyethylene insert in a fixed-bearing total knee arthroplasty are presented. This brief report demonstrates the presentation of this rare mode of failure and highlights the unique complications associated with its treatment. [ABSTRACT FROM AUTHOR]