Second Generation Patient Specific Total Knees Demonstrate a Higher Manipulation Rate Compared with “Off-the-shelf” Implants

Introduction. Patient specific total knee arthroplasty (TKA) theoreticallyprovides a more accurate fit to the native knee but mayhave difficulty achieving full range of motion (ROM) post-operatively.Post-operative ROM data were compared between patientswho underwent cemented patient-specific cruciate-retaining(PSCR) and standard cemented posterior-stabilized (SPS) TKAs. Methods. PSCR and SPS TKAs that were performed from January2014 to September 2015 by the same surgeon using the same postoperativeprotocols at two selected facilities were reviewed. Twoandsix-week post-operative ROM data were obtained and thenumber of patients with knee flexion less than 110° was recorded. Results. Twenty-one patients in the PSCR group and 57 patientsin the SPS group were included. The percentage of patientswith knee flexion less than 110° was similar in both groups preoperatively(10% vs 14%, p = 0.60) and two-week post-operatively(57% vs 68%, p = 0.35). However, at six-week post-operativelythere was significant difference (29% vs 7%, p = 0.01). Conclusions. These results provide evidence to alert orthopaedicsurgeons when using these patient specific implants versus conventionalTKA methods. Patients whose TKA was performed usingpatient specific cutting guides struggled to obtain 110° of kneeflexion. Close monitoring, aggressive physical therapy, and earlymanipulation are recommended when using patient specific cuttingguides and custom total knee implants. Further evaluation ina larger group of patients is warranted. KS J Med 2016;9(4):88-92

Early Outcomes of Cemented versus Cementless Total Knee Arthroplasty

Introduction. Total knee arthroplasty (TKA) has been provento be very effective for long-term pain relief in the degenerativeknee. Few studies have investigated short-term clinicaland functional outcomes between the cemented and cementlessTKA. The specific aim of this study was to assess the potentialdifference of functional outcomes in the early postoperativeperiod between these two surgical options usingthe Knee Society Score (KSS) and range of motion (ROM). Methods. A total of 164 knees that had undergone TKA by a singlesurgeon at a single institution between 2007 and 2010 were reviewed.Three different TKA prosthetic designs (cruciate retaining(CR), posterior stabilized (PS) and cruciate substituting (CS))were included. Data collection included patient demographics,pre- and post-operative ROM, and pre- and post-operative KSSat each visit (1.5 months, 3 months, and 12 months). Two separateKSS scores were assigned: functional score and clinical score. Results. Sixty-seven knees underwent cemented TKA and 97knees underwent cementless TKA. No significant differencewas recognized in either age or body mass index for thesetwo TKA groups. The cementless group showed a significantearly ROM improvement after 1.5 months post-operative (p <0.05), while the cemented group showed ROM improvementonly after three months post-operative. No significant differencewas detected in terms of KSS between the cemented andcementless TKA groups at each measured time period. Bothgroups showed marked KSS improvement (cemented: 135%,cementless: 125%) after 1.5 months post-operative and theKSS seemed to be stabilized after three months post-operativefor both groups (cemented: p = 0.36; cementless: p = 0.07). Conclusions. There was a significant early ROM improvementfor the cementless TKA group compared to the cementedTKA group, but no statistical significant difference was notedin KSS in the early post-operative period when comparing cementedand cementless TKA groups. The findings provide evidencethat cementless TKA patients can undergo an identicalpost-operative protocol to cemented TKA, without concernsabout implant stability or function. KS J Med 2016;9(4):93-98

Variable Angle Locking Compression Plate as Alternative Fixation for Jones Fractures:: A Case Series

Introduction. Jones fractures pose many challenges for the treatingsurgeon and can cause significant disability for some patients. Theaim of this study was to review the results of using a variable anglelocking compression plate as an alternative fixation method in thetreatment of Jones fractures.Methods.xA retrospective chart review was conducted of patientswho had undergone fixation of Jones fracture with a variable anglelocking compression plate from September 2012 through February2016. Radiographs of the preoperative and six-week postoperativeand postoperative follow-up outcomes, including complication andhardware removal, were collected.Results. Twenty-three cases met the inclusion/exclusion criteria.The overall bony union rate was 96% at six-week postoperative and100% at 20-week postoperative. Mean age was 30 ± 16 years, andmean BMI was 30.7 ± 5.2 kg/m2. Three patients (13%) had plateremoval: two (9%) were due to irritation caused by shoe wearing andone patient (4%) had a skin infection (cellulitis) which was treatedwith intravenous antibiotics. One patient (4%) had developed deepvein thrombosis (DVT) that was resolved with anticoagulant withoutimplant removal. No fixation loss and no associated complicationsdeveloped from implant removal.Conclusions. Based on our limited experience, this study providedevidence that the variable angle locking compression plate may be analternative form of fixation for Jones fractures with a low complicationrate. This procedure seemed to provide a safe, reliable methodthat can achieve an anatomic reduction, stable fixation, rapid healing,and good results in the treatment of Jones fractures.Kans J Med 2019;12(2):28-32

The Cost of Routine Follow-Up in Total Joint Arthroplasty and the Influence of These Visits on Treatment Plans

Introduction. Many physicians recommend annual or biennial visitsafter total hip and knee arthroplasty (THA and TKA). This studysought to establish the cost of a post-operative visit to both the healthcare system and patient and identify if these visits altered patientmanagement. Methods. A prospective cohort study was conducted using patientspresenting for follow-up after THA or TKA from April throughDecember 2016. All surgeries were performed by a single orthopaedicsurgeon in Wichita, Kansas. All eligible subjects that met the inclusioncriteria received and completed a questionnaire about the personalcost of the visit and their assessment of their function and outcomeafter total joint arthroplasty. The physician also completed a questionnairethat examined the cost of the visit to the health care systemand whether the clinical or radiographic findings altered patient management. Results. Fifty-six patients participated with an average length of follow-up of 4.5 ± 4.1 years since surgery. The average patient cost was$135.20 ±$190.53 (range, $1.65 -$995.88), and the average visit timefor the patient was 3.9 ± 2.9 hours. Eighty percent of patients reportedno pain during the clinic encounter, and 11% reported loss of function.Eighty-four percent thought the visit was necessary. Physician timefor each visit lasted 12.9 ± 3.7 minutes (range, 10 - 20 minutes). Only9% of patient encounters resulted in an alteration in patient management.This occurred at an average follow-up time of 3.6 ± 1.8 yearsafter the index procedure. The average cost of each visit to the healthcare system at large was $117.31 ± 60.53 (range,$93.90 - $428.28). Conclusions. The findings of this study advise total joint patients andorthopaedic surgeons regarding the cost of routine post-operativeappointments and whether these visits alter patient management.The majority of the routine follow-up visits after THA and TKA didnot result in an alteration in patient management, but added substantialcost to the health care system. Kans J Med 2018;11(3):59-66

Bilateral Pectoralis Major Tendon Rupture While Performing Intermediate Level Bench Press

Simultaneous bilateral pectoralis major (PM) tendon rupture is a rare injury. To our knowledge, there have been only three previously reported cases of this type of injury.1–3 These patients sustained the injury while attempting a 360° turn on gymnastic rings,1 bench-pressing a heavier-than-normal load without an appropriate warm-up period,2 and performing dips on wide-grip parallel bars.3 We present a case of a patient who sustained simultaneous bilateral PM tendon ruptures while performing intermediate level bench-pressing with an appropriate warm-up period

Complex Coacervate Materials as Artificial Cells

Cells have evolved to be self-sustaining compartmentalized systems that consist of many thousands of biomolecules and metabolites interacting in complex cycles and reaction networks. Numerous subtle intricacies of these self-assembled structures are still largely unknown. The importance of liquid-liquid phase separation (both membraneless and membrane bound) is, however, recognized as playing an important role in achieving biological function that is controlled in time and space. Reconstituting biochemical reactions in vitro has been a success of the last decades, for example, establishment of the minimal set of enzymes and nutrients able to replicate cellular activities like the in vitro transcription translation of genes to proteins. Further than this though, artificial cell research has the aim of combining synthetic materials and nonliving macromolecules into ordered assemblies with the ability to carry out more complex and ambitious cell-like functions. These activities can provide insights into fundamental cell processes in simplified and idealized systems but could also have an applied impact in synthetic biology and biotechnology in the future. To date, strategies for the bottom-up fabrication of micrometer scale life-like artificial cells have included stabilized water-in-oil droplets, giant unilamellar vesicles (GUV’s), hydrogels, and complex coacervates. Water-in-oil droplets are a valuable and easy to produce model system for studying cell-like processes; however, the lack of a crowded interior can limit these artificial cells in mimicking life more closely. Similarly membrane stabilized vesicles, such as GUV’s, have the additional membrane feature of cells but still lack a macromolecularly crowded cytoplasm. Hydrogel-based artificial cells have a macromolecularly dense interior (although cross-linked) that better mimics cells, in addition to mechanical properties more similar to the viscoelasticity seen in cells but could be seen as being not dynamic in nature and limiting to the diffusion of biomolecules. On the other hand, liquid-liquid phase separated complex coacervates are an ideal platform for artificial cells as they can most accurately mimic the crowded, viscous, highly charged nature of the eukaryotic cytoplasm. Other important key features that researchers in the field target include stabilizing semipermeable membranes, compartmentalization, information transfer/communication, motility, and metabolism/growth. In this Account, we will briefly cover aspects of coacervation theory and then outline key cases of synthetic coacervate materials used as artificial cells (ranging from polypeptides, modified polysaccharides, polyacrylates, and polymethacrylates, and allyl polymers), finishing with envisioned opportunities and potential applications for coacervate artificial cells moving forward.</p

Toward Artificial Cell-Mediated Tissue Engineering:A New Perspective

The fast-growing pace of regenerative medicine research has allowed the development of a range of novel approaches to tissue engineering applications. Until recently, the main points of interest in the majority of studies have been to combine different materials to control cellular behavior and use different techniques to optimize tissue formation, from 3-D bioprinting to in situ regeneration. However, with the increase of the understanding of the fundamentals of cellular organization, tissue development, and regeneration, has also come the realization that for the next step in tissue engineering, a higher level of spatiotemporal control on cell-matrix interactions is required. It is proposed that the combination of artificial cell research with tissue engineering could provide a route toward control over complex tissue development. By equipping artificial cells with the underlying mechanisms of cellular functions, such as communication mechanisms, migration behavior, or the coherent behavior of cells depending on the surrounding matrix properties, they can be applied in instructing native cells into desired differentiation behavior at a resolution not to be attained with traditional matrix materials.</p

A novel approach and software component for supporting competence-based learning with serious games

Digital educational games constitute a major opportunity for acquiring knowledge and competences in a different way than traditional classroom- and technology-based methods. This paper presents a novel approach for a game component that structures the game play in an adaptive way. This approach consists of a combination of three learning theories and techniques. First, Competence-based Knowledge Space Theory is used structure a knowledge domain into competences and game situations. Second, the Leitner system of flashcards is used to establish structured and timed repetition of competences to be acquired. Third, the Ebbinghaus forgetting curve is taken into account to model forgetting learned competences. This approach has been implemented as a game component in line with the games component architecture of the RAGE project. The design and development of this component followed the requirements of the French games company Kiupe that includes it in its environment of games and mini-games

Tuning of Cationic Polymer Functionality in Complex Coacervate Artificial Cells for Optimized Enzyme Activity

Complex coacervates are a versatile platform to mimic the structure of living cells. In both living systems and artificial cells, a macromolecularly crowded condensate phase has been shown to be able to modulate enzyme activity. Yet, how enzyme activity is affected by interactions (particularly with cationic charges) inside coacervates is not well studied. Here, we synthesized a series of amino-functional polymers to investigate the effect of the type of amine and charge density on coacervate formation, stability, protein partitioning, and enzyme function. The polymers were prepared by RAFT polymerization using as monomers aminoethyl methacrylate (AEAM), 2-(dimethylamino)ethyl methacrylate (DMAEMA), imidazolepropyl methacrylamide (IPMAm), and [2-(methacryloyloxy)ethyl] trimethylammonium chloride (TMAEMA). Membranized complex coacervate artificial cells were formed with these polycations and an anionic amylose derivative. Results show that polycations with reduced charge density result in higher protein mobility in the condensates and also higher enzyme activity. Insights described here could help guide the use of coacervate artificial cells in applications such as sensing, catalysis, and therapeutic formulations.</p