scholarly journals Intra-Operative Soft Tissue Targets For Improved Outcomes In Total Knee Arthroplasty

10.29007/3plz ◽  
2020 ◽  
Author(s):  
Edgar Wakelin ◽  
Sami Shalhoub ◽  
Jeffrey Lawrence ◽  
John Keggi ◽  
Jeffrey DeClaire ◽  
...  
Keyword(s):  
Minimally Clinically Important Difference ◽  
Pain Scores ◽  
Improved Outcomes ◽  
Joint Gap ◽  
Digitally Controlled ◽  
Pain Outcome ◽  
Total Knee ◽  
Stiff Joint ◽  
Definition Of ◽  
Quantitative Definition

A poorly balanced, unstable or stiff joint is a leading cause of dissatisfaction and revision after surgery. The quantitative definition of a well-balanced joint, however, remains a source of controversy. This study investigates joint gaps measured by a digitally-controlled ligament tensioning device throughout flexion and its effect on post- operative outcome.Surgeries were performed using the OMNIBotics robot-assisted TKA platform and BalanceBot device. Joint gaps were recorded by the BalanceBot throughout flexion during trialing. Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected at 1-year post-op. Correlations between joint gaps and KOOS outcome were investigated.Knees that reported: a medial gap ≤ lateral gap in extension (p = 0.007, median ∆ = 8.3); an average joint gap of between 1 mm tighter and 1 mm looser than the final insert thickness in midflexion (p = 0.006, median ∆ = 5.5); and an imbalance of less than 1.5 mm in flexion (p = 0.012, median ∆ = 2.8) reported significantly improved pain scores. Patients which satisfied both extension and flexion criteria, or midflexion and flexion criteria reported improved outcomes compared to those which satisfied only one or neither criterion (p = 0.0002, median ∆ = 9.7, p = 0.0019, median ∆ = 8.4 respectively).KOOS Pain scores correlated with joint gap measurements across all flexion angles investigated. Combining joint gap windows, subgroups of patients were found that reported a change in the median KOOS Pain outcome beyond the minimally clinically important difference.

scholarly journals The Effect of Coronal and Axial Femoral Component Rotation on Midflexion Laxity and Patient Reported Outcomes in Total Knee Arthroplasty

10.29007/km58 ◽  
2020 ◽  
Author(s):  
Edgar Wakelin ◽  
Sami Shalhoub ◽  
Jeffrey Lawrence ◽  
John Keggi ◽  
Amber Randall ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Axial Rotation ◽  
Improved Outcomes ◽  
Joint Gap ◽  
Component Rotation ◽  
Patient Reported ◽  
Total Knee ◽  
Multi Center Study ◽  
Line P

Joint balance in total knee arthroplasty (TKA) has traditionally focused on achieving a tight symmetric extension gap and rectangular or trapezoidal gaps in flexion. This study sought to investigate the effect of femoral and tibial coronal rotation and femoral axial rotation on midflexion coronal joint balance and patient outcomes.A prospective multi-center study was performed with a mixture of tibia-first gap-balancing and femur-first approaches were performed using the Corin OMNIBotics robot-assisted TKA platform with APEX implant components. Coronal and axial femoral and tibial resections were recorded by the platform. Medial and lateral joint gaps were recorded while applying a computer-controlled load to the joint throughout flexion during trialing using the Corin BalanceBot device. In addition, 1-year Knee Injury and Osteoarthritis Outcome Score (KOOS) and PROMIS-10 global health scores were collected.231 surgeries were identified: 66.9±8.1 years, 31.4±4.8 kg/m2 and 57% female (121) with a mean pre-operative HKA angle of 4.5±5.2° varus. A significant correlation was found between the medio-lateral (ML) joint gap difference in midflexion and both extension and flexion joint line (p=0.003, r2=-0.20, p=0.001, r2=-0.22, respectively). A significant correlation was found between midflexion ML imbalance and KOOS stiffness questions at 3 M and 6 M post-op (r2=-0.15, p=0.036, r2=-0.18, p=0.013), in which a more balanced knee correlated with improved outcomes.Treating flexion and extension joint balance in isolation may not capture the effect on midflexion laxity. Component placement should take in to account the effect on joint gaps throughout flexion to target optimal joint balance.

Improved total knee arthroplasty pain outcome when joint gap targets are achieved throughout flexion

2021 ◽  
Author(s):  
Edgar A. Wakelin ◽  
Sami Shalhoub ◽  
Jeffrey M. Lawrence ◽  
John M. Keggi ◽  
Jeffrey H. DeClaire ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Joint Gap ◽  
Pain Outcome ◽  
Total Knee

scholarly journals Accuracy of total knee arthroplasty using the modified gap technique based on the bone gap: an evaluation of the bone gap with a distal femoral trial component

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Goki Kamei ◽  
Shigeki Ishibashi ◽  
Koki Yoshioka ◽  
Satoru Sakurai ◽  
Hiroyuki Inoue ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Distal Femur ◽  
Gap Size ◽  
Flexion Gap ◽  
Gap Technique ◽  
Joint Gap ◽  
Total Knee ◽  
The Mean

Abstract Background In total knee arthroplasty (TKA) using the modified gap technique, the soft-tissue balance is measured after osteotomy of the distal femur and proximal tibia (conventional bone gap). However, after osteotomy, the flexion gap size during 90° knee flexion may be larger than that observed after implantation. The tension of the lateral compartment during 90° flexion may also be reduced after osteotomy of the distal femur. We manufactured a distal femoral trial component to reproduce the condition after implantation and prior to posterior condyle osteotomy. This study aimed to evaluate the effect of the trial component on the flexion gap. Methods This prospective study included 21 consecutive patients aged 78 years with medial osteoarthritis who underwent cruciate-retaining TKA between February 2017 and March 2018. The postoperative flexion gap size and inclination during 90° flexion were compared between cases with and without the trial component. Results The mean joint gap size with the trial component (13.4 ± 0.80 mm) was significantly smaller than that without the trial component (14.7 ± 0.84 mm). The mean gap inclination angle with the trial component (3.7° ± 0.62°) was significantly smaller than that without the trial component (5.5° ± 0.78°). Conclusions In the present study, the joint gap size and medial tension were significantly reduced after the trial component had been set. Accurate measurement of the soft-tissue balance is an important factor in the modified gap technique, and this method using a distal femoral trial component can offer better outcomes than those achieved with conventional methods.

scholarly journals Defining and Quantifying Intermittency in the Power Sector

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3366
Author(s):  
Daniel Suchet ◽  
Adrien Jeantet ◽  
Thomas Elghozi ◽  
Zacharie Jehl
Keyword(s):  
Power Source ◽  
Production Data ◽  
Power Sector ◽  
Predictive Capacity ◽  
The Public ◽  
Current State ◽  
Definition Of ◽  
Quantitative Definition ◽  
The Impact

The lack of a systematic definition of intermittency in the power sector blurs the use of this term in the public debate: the same power source can be described as stable or intermittent, depending on the standpoint of the authors. This work tackles a quantitative definition of intermittency adapted to the power sector, linked to the nature of the source, and not to the current state of the energy mix or the production predictive capacity. A quantitative indicator is devised, discussed and graphically depicted. A case study is illustrated by the analysis of the 2018 production data in France and then developed further to evaluate the impact of two methods often considered to reduce intermittency: aggregation and complementarity between wind and solar productions.

Joint gap measurement in total knee arthroplasty using a tensor device with the same articulating surface as the prosthesis

2014 ◽  
Vol 134 (5) ◽  
pp. 699-705 ◽  
Author(s):  
Yoshio Matsui ◽  
Shigeru Nakagawa ◽  
Yukihide Minoda ◽  
Shigekazu Mizokawa ◽  
Yoshio Tokuhara ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Gap Measurement ◽  
Joint Gap ◽  
Total Knee ◽  
Articulating Surface

scholarly journals What is a balanced knee replacement?

2018 ◽  
Vol 3 (12) ◽  
pp. 614-619 ◽  
Author(s):  
Lucy C. Walker ◽  
Nick D. Clement ◽  
Kanishka M. Ghosh ◽  
David J. Deehan
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Replacement ◽  
Knee Arthroplasty ◽  
Current Evidence ◽  
Soft Tissue Envelope ◽  
Total Knee ◽  
Uneven Wear ◽  
Definition Of ◽  
Revision Tka

For multifactorial reasons an estimated 20% of patients remain unsatisfied after total knee arthroplasty (TKA). Appropriate tension of the soft tissue envelope encompassing the knee is important in total knee arthroplasty and soft tissue imbalance contributes to several of the foremost reasons for revision TKA, including instability, stiffness and aseptic loosening. There is debate in the literature surrounding the optimum way to achieve balancing of a total knee arthroplasty and there is also a lack of an accepted definition of what a balanced knee replacement is. It may be intuitive to use the native knee as a model for balancing; however, there are many difficulties with translating this into a successful prosthesis. One of the foundations of TKA, as described by Insall, was that although the native knee has more weight transmitted through the medial compartment this was to be avoided in a TKA as it would lead to uneven wear and early failure. There is a focus on achieving symmetrical tension and pressure and subsequent ‘balance’ in TKA, but the evidence from cadaveric studies is that the native knee is not symmetrically balanced. As we are currently trying to design an implant that is not based on its anatomical counterpart, is it possible to create a truly balanced prosthesis or to even to define what that balance is? The authors have reviewed the current evidence surrounding TKA balancing and its relationship with the native knee. Cite this article: EFORT Open Rev 2018;3:614-619. DOI: 10.1302/2058-5241.3.180008.

scholarly journals Quantifying Legal Entropy

2021 ◽  
Vol 9 ◽  
Author(s):  
Ted Sichelman
Keyword(s):  
Information Theory ◽  
Information Content ◽  
Legal System ◽  
Legal Systems ◽  
Information Costs ◽  
Precise Quantification ◽  
The Law ◽  
Legal Contexts ◽  
Definition Of ◽  
Quantitative Definition

Many scholars have employed the term “entropy” in the context of law and legal systems to roughly refer to the amount of “uncertainty” present in a given law, doctrine, or legal system. Just a few of these scholars have attempted to formulate a quantitative definition of legal entropy, and none have provided a precise formula usable across a variety of legal contexts. Here, relying upon Claude Shannon's definition of entropy in the context of information theory, I provide a quantitative formalization of entropy in delineating, interpreting, and applying the law. In addition to offering a precise quantification of uncertainty and the information content of the law, the approach offered here provides other benefits. For example, it offers a more comprehensive account of the uses and limits of “modularity” in the law—namely, using the terminology of Henry Smith, the use of legal “boundaries” (be they spatial or intangible) that “economize on information costs” by “hiding” classes of information “behind” those boundaries. In general, much of the “work” performed by the legal system is to reduce legal entropy by delineating, interpreting, and applying the law, a process that can in principle be quantified.

scholarly journals Tranexamic Acid Increases Early Postoperative Pain and Decreases Time to First Opioid Following Total Knee Arthroplasty

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Sachin Seetharam ◽  
Sydney Keller ◽  
Mary Ziemba-Davis ◽  
R. Michael Meneghini MD
Keyword(s):  
Total Knee Arthroplasty ◽  
Postoperative Pain ◽  
Blood Loss ◽  
Tranexamic Acid ◽  
Knee Arthroplasty ◽  
Ex Vivo ◽  
Pain Scores ◽  
Average Pain ◽  
Total Knee

Background and Hypothesis: Tranexamic acid (TXA) decreases blood loss in total knee arthroplasty (TKA). However, TXA evoked pain in rats by inhibiting GABA and glycine receptors in the spinal dorsal horn, and caused cellular death in ex vivo and in vitro human periarticular tissues exposed to clinical concentrations of TXA. We evaluated inpatient postoperative pain and blood loss in TKA performed with and without TXA. Project Methods: 105 consecutive cemented TKAs without TXA were compared to 72 consecutive cemented TKAs with TXA. Procedures were performed by a single surgeon using identical perioperative medical and pain-control protocols. Outcomes included: average of q2-4 hour pain scores during the first 24 hours after PACU discharge, average pain during remainder of stay, final pain score prior to discharge, time in minutes to first opioid after PACU discharge, total opioids in morphine equivalents (MEQs) during the first 24 hours after PACU discharge, average MEQs per remaining days of stay, and mean g/dL pre- to postoperative decrease in hemoglobin. Multivariate analyses accounted for 15 demographics and covariates. Results: The sex (p=0.393), age (p=0.784), and BMI (p=0.930) of the two cohorts were similar. Mean pain during the first 24 hours was greater (4.1 vs. 3.2, p=0.001), MEQs consumed during the first 24 hours were greater (45 vs. 37, p=0.069), and time to first opioid medication was shorter (326 vs. 414, p=0.023) in patients who received TXA. The decrease in hemoglobin was less in patients who received TXA (-2.2 vs. -2.7, p<0.001).   Conclusion and Potential Impact: Our hypothesis based on animal and laboratory studies that TXA may increase early postoperative pain was confirmed by three metrics. Consistent with the effective life of TXA, pain and opioid consumption after 24 hours did not differ based on TXA use. Further work is warranted to investigate the nature consequences associated with TXA, relative to its demonstrated benefits for blood conservation.  

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