The optimal management of an infrapopliteal deep venous thrombosis (IDVT) following total knee arthroplasty (TKA) remains unknown. The risk of DVT propagation and symptom progression must be balanced against potential haemorrhagic complications associated with administration of anticoagulation therapy. The current study reports on a cohort of patients diagnosed with IDVT following TKA who were treated with aspirin, followed closely for development of symptoms, and scanned with ultrasound to determine resolution of IDVT. Among a cohort of 5,078 patients undergoing TKA, 532 patients (695 TKAs, 12.6%) developed an IDVT between 1 January 2014 to 31 December 2019 at a single institution, as diagnosed using Doppler ultrasound at the first postoperative visit. Of the entire cohort of 532 patients with IDVT, 91.4% (486/532) were treated with aspirin (325 mg twice daily) and followed closely. Repeat lower limb ultrasound was performed four weeks later to evaluate the status of IDVT.Aims
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The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of ceramic femoral components. Optical profilometry was used to evaluate surface roughness and to examine the features created by the wear process in a knee wear simulator. We developed a method of measuring surface changes on five CoCr femoral components and quantifying the loss of material from the articular surface during the wear process. We also examined the articular surface of three ceramic femoral components from a previous test for evidence of surface damage, and compared it with that of CoCr components.Aims
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Many patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis (OA) in both knees and may consider either simultaneous or staged bilateral TKA. The implications of simultaneous versus staged bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared with the sum of days missed from each operation for patients who underwent staged bilateral TKA. The prospective arthroplasty registry at the Hospital for Special Surgery was used. Baseline characteristics and patient-reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounding variables including age, sex, preoperative BMI, and type of work (sedentary, moderate, high activity, or strenuous), to analyze time lost from work after simultaneous compared with staged bilateral TKA.Aims
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The COVID-19 pandemic led to a swift adoption of telehealth in orthopaedic surgery. This study aimed to analyze the satisfaction of patients and surgeons with the rapid expansion of telehealth at this time within the division of adult reconstructive surgery at a major urban academic tertiary hospital. A total of 334 patients underging arthroplasty of the hip or knee who completed a telemedicine visit between 30 March and 30 April 2020 were sent a 14-question survey, scored on a five-point Likert scale. Eight adult reconstructive surgeons who used telemedicine during this time were sent a separate 14-question survey at the end of the study period. Factors influencing patient satisfaction were determined using univariate and multivariate ordinal logistic regression modelling.Aims
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The management of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is challenging. The correct antibiotic management remains elusive due to differences in epidemiology and resistance between countries, and reports in the literature. Before the efficacy of surgical treatment is investigated, it is crucial to analyze the bacterial strains causing PJI, especially for patients in whom no organisms are grown. A review of all revision TKAs which were undertaken between 2006 and 2018 in a tertiary referral centre was performed, including all those meeting the consensus criteria for PJI, in which organisms were identified. Using a cluster analysis, three chronological time periods were created. We then evaluated the antibiotic resistance of the identified bacteria between these three clusters and the effectiveness of our antibiotic regime.Aims
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Alternative alignment concepts, including kinematic and restricted kinematic, have been introduced to help improve clinical outcomes following total knee arthroplasty (TKA). The purpose of this study was to evaluate the clinical results, along with patient satisfaction, following TKA using the concept of restricted kinematic alignment. A total of 121 consecutive TKAs performed between 11 February 2018 to 11 June 2019 with preoperative varus deformity were reviewed at minimum one-year follow-up. Three knees were excluded due to severe preoperative varus deformity greater than 15°, and a further three due to requiring revision surgery, leaving 109 patients and 115 knees to undergo primary TKA using the concept of restricted kinematic alignment with advanced technology. Patients were stratified into three groups based on the preoperative limb varus deformity: Group A with 1° to 5° varus (43 knees); Group B between 6° and 10° varus (56 knees); and Group C with varus greater than 10° (16 knees). This study group was compared with a matched cohort of 115 TKAs and 115 patients using a neutral mechanical alignment target with manual instruments performed from 24 October 2016 to 14 January 2019.Aims
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Robotic-assisted total knee arthroplasty (RA-TKA) is theoretically more accurate for component positioning than TKA performed with mechanical instruments (M-TKA). Furthermore, the ability to incorporate soft-tissue laxity data into the plan prior to bone resection should reduce variability between the planned polyethylene thickness and the final implanted polyethylene. The purpose of this study was to compare accuracy to plan for component positioning and precision, as demonstrated by deviation from plan for polyethylene insert thickness in measured-resection RA-TKA versus M-TKA. A total of 220 consecutive primary TKAs between May 2016 and November 2018, performed by a single surgeon, were reviewed. Planned coronal plane component alignment and overall limb alignment were all 0° to the mechanical axis; tibial posterior slope was 2°; and polyethylene thickness was 9 mm. For RA-TKA, individual component position was adjusted to assist gap-balancing but planned coronal plane alignment for the femoral and tibial components and overall limb alignment remained 0 ± 3°; planned tibial posterior slope was 1.5°. Mean deviations from plan for each parameter were compared between groups for positioning and size and outliers were assessed.Aims
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To establish our early clinical results of a new total knee arthroplasty (TKA) tibial component introduced in 2013 and compare it to other designs in use at our hospital during the same period. This is a retrospective study of 166 (154 patients) consecutive cemented, fixed bearing, posterior-stabilized (PS) TKAs (ATTUNE) at one hospital performed by five surgeons. These were compared with a reference cohort of 511 knees (470 patients) of other designs (seven manufacturers) performed at the same hospital by the same surgeons. There were no significant differences in age, sex, BMI, or follow-up times between the two cohorts. The primary outcome was revision performed or pending.Aims
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To describe the risk of periprosthetic joint infection (PJI) and reoperation in patients who have an acute, traumatic wound dehiscence following total knee arthroplasty (TKA). From January 2002 to December 2018, 16,134 primary TKAs were performed at a single institution. A total of 26 patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68 years (44 to 87), 38% (n = 10) were female, and mean BMI was 34 kg/m2 (23 to 48). Median time to dehiscence was 13 days (interquartile range (IQR) 4 to 15). The dehiscence resulted from a fall in 22 patients and sudden flexion after staple removal in four. The arthrotomy was also disrupted in 58% (n = 15), including a complete extensor mechanism disruption in four knees. An irrigation and debridement with component retention (IDCR) was performed within 48 hours in 19 of 26 knees and two-thirds were discharged on antibiotic therapy. The mean follow-up was six years (2 to 15). The association of wound dehiscence and the risk of developing a PJI was analyzed.Aims
Methods
There is concern that aggressive target pricing in the new Bundled Payment for Care Improvement Advanced (BPCI-A) penalizes high-performing groups that had achieved low costs through prior experience in bundled payments. We hypothesize that this methodology incorporates unsustainable downward trends on Target Prices and will lead to groups opting out of BPCI Advanced in favour of a traditional fee for service. Using the Centers for Medicare and Medicaid Services (CMS) data, we compared the Target Price factors for hospitals and physician groups that participated in both BPCI Classic and BPCI Advanced (legacy groups), with groups that only participated in BPCI Advanced (non-legacy). With rebasing of Target Prices in 2020 and opportunity for participants to drop out, we compared retention rates of hospitals and physician groups enrolled at the onset of BPCI Advanced with current enrolment in 2020.Aims
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It remains difficult to diagnose early postoperative periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). We aimed to validate the optimal cutoff values of ESR, CRP, and synovial fluid analysis for detecting early postoperative PJI in a large series of primary TKAs. We retrospectively identified 27,066 primary TKAs performed between 2000 and 2019. Within 12 weeks, 169 patients (170 TKAs) had an aspiration. The patients were divided into two groups: those evaluated ≤ six weeks, or between six and 12 weeks postoperatively. The 2011 Musculoskeletal Infection Society (MSIS) criteria for PJI diagnosis in 22 TKAs. The mean follow-up was five years (two months to 17 years). The results were compared using medians and Mann-Whitney U tests and thresholds were analyzed using receiver operator characteristic curves.Aims
Methods
Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture, which leads to femoral joint line elevation. There is a paucity of data describing the effect of joint line elevation on mid-flexion stability and knee kinematics. Thus, the goal of this study was to quantify the effect of joint line elevation on mid-flexion laxity. Six computational knee models with cadaver-specific capsular and collateral ligament properties were implanted with a posterior-stabilized (PS) TKA. A 10° flexion contracture was created in each model to simulate a capsular contracture. Distal femoral resections of + 2 mm and + 4 mm were then simulated for each knee. The knee models were then extended under a standard moment. Subsequently, varus and valgus moments of 10 Nm were applied as the knee was flexed from 0° to 90° at baseline and repeated after each of the two distal resections. Coronal laxity (the sum of varus and valgus angulation with respective maximum moments) was measured throughout flexion.Aims
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Debridement, antibiotics, and implant retention (DAIR) remains one option for the treatment of acute periprosthetic joint infection (PJI) despite imperfect success rates. Intraosseous (IO) administration of vancomycin results in significantly increased local bone and tissue concentrations compared to systemic antibiotics alone. The purpose of this study was to evaluate if the addition of a single dose of IO regional antibiotics to our protocol at the time of DAIR would improve outcomes. A retrospective case series of 35 PJI TKA patients, with a median age of 67 years (interquartile range (IQR) 61 to 75), who underwent DAIR combined with IO vancomycin (500 mg), was performed with minimum 12 months' follow-up. A total of 26 patients with primary implants were treated for acute perioperative or acute haematogenous infections. Additionally, nine patients were treated for chronic infections with components that were considered unresectable. Primary outcome was defined by no reoperations for infection, nor clinical signs or symptoms of PJI.Aims
Methods
The aim of this study was to compare ten-year longitudinal healthcare costs and revision rates for patients undergoing unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The Humana database was used to compare 2,383 patients undergoing UKA between 2007 and 2009, who were matched 1:1 from a cohort of 63,036 patients undergoing primary TKA based on age, sex, and Elixhauser Comorbidity Index. Medical and surgical complications were tracked longitudinally for one year following surgery. Rates of revision surgery and cumulative mean healthcare costs were recorded for this period of time and compared between the cohorts.Aims
Methods
Social determinants of health (SDOHs) may contribute to the total cost of care (TCOC) for patients undergoing total knee arthroplasty (TKA). The aim of this study was to investigate the association between demographic data, health status, and SDOHs on 30-day length of stay (LOS) and TCOC after this procedure. Patients who underwent TKA between 1 January 2018 and 31 December 2019 were identified. A total of 234 patients with complete SDOH data were included. Data were drawn from the Chesapeake Regional Information System, the Centers for Disease Control social vulnerability index (SVI), the US Department of Agriculture, and institutional electronic medical records. The SVI identifies areas vulnerable to catastrophic events with four themed scores: socioeconomic status; household composition and disability; minority status and language; and housing and transportation. Food deserts were defined as neighbourhoods located one or ten miles from a grocery store in urban and rural areas, respectively. Multiple regression analyses were performed to determine associations with LOS and costs after controlling for various demographic parameters.Aims
Methods
Porous metaphyseal cones can be used for fixation in revision total knee arthroplasty (rTKA) and complex TKAs. This metaphyseal fixation has led to some surgeons using shorter cemented stems instead of diaphyseal engaging cementless stems with a potential benefit of ease of obtaining proper alignment without being beholden to the diaphysis. The purpose of this study was to evaluate short term clinical and radiographic outcomes of a series of TKA cases performed using 3D-printed metaphyseal cones. A retrospective review of 86 rTKAs and nine complex primary TKAs, with an average age of 63.2 years (SD 8.2) and BMI of 34.0 kg/m2 (SD 8.7), in which metaphyseal cones were used for both femoral and tibial fixation were compared for their knee alignment based on the type of stem used. Overall, 22 knees had cementless stems on both sides, 52 had cemented stems on both sides, and 15 had mixed stems. Postoperative long-standing radiographs were evaluated for coronal and sagittal plane alignment. Adjusted logistic regression models were run to assess malalignment hip-knee-ankle (HKA) alignment beyond ± 3° and sagittal alignment of the tibial and femoral components ± 3° by stem type.Aims
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This study aimed to determine outcomes of isolated tibial insert exchange (ITIE) during revision total knee arthroplasty (TKA). From 1985 to 2016, 270 ITIEs were performed at one institution for instability (55%, n = 148), polyethylene wear (39%, n = 105), insert fracture/dissociation (5%, n = 14), or stiffness (1%, n = 3). Patients with component loosening, implant malposition, infection, and extensor mechanism problems were excluded.Aims
Methods
Neither a surgeon’s intraoperative impression nor the parameters of computer navigation have been shown to be predictive of the outcomes following total knee arthroplasty (TKA). The aim of this study was to determine whether a surgeon, with robotic assistance, can predict the outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain (KPS), one year postoperatively, and establish what factors correlate with poor KOOS scores in a well-aligned and balanced TKA. A total of 134 consecutive patients who underwent TKA using a dynamic ligament tensioning robotic system with a tibia first resection technique and a cruciate sacrificing ultracongruent TKA system were enrolled into a prospective study. Each TKA was graded based on the final mediolateral ligament balance at 10° and 90° of flexion: 1) < 1 mm difference in the thickness of the tibial insert and that which was planned (n = 75); 2) < 1 mm difference (n = 26); 3) between 1 mm to 2 mm difference (n = 26); and 4) > 2 mm difference (n = 7). The mean one-year KPS score for each grade of TKA was compared and the likelihood of achieving an KPS score of > 90 was calculated. Finally, the factors associated with lower KPS despite achieving a high-grade TKA (grade A and B) were analyzed.Aims
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A limited number of investigations with conflicting results have described perivascular lymphocytic infiltration (PVLI) in the setting of total knee arthroplasty (TKA). The purpose of this study was to determine if PVLI found in TKAs at the time of aseptic revision surgery was associated with worse clinical outcomes and survivorship. A retrospective review was conducted on 617 patients who underwent aseptic TKA revision who had histological analysis for PVLI at the time of surgery. Clinical and radiological data were obtained pre- and postoperatively, six weeks postoperatively, and then every year thereafter.Aims
Methods
Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes. On 1 July 2019, we discontinued the use of intraoperative LB as part of a periarticular injection protocol. A consecutive group of patients who received LB as part of the protocol (Protocol 1) and a subsequent group who did not (Protocol 2) were compared. All patients received the same opioid-sparing protocol. Verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Events relating to the opiate administration were derived as morphine milligram equivalences (MMEs) per patient per 24-hour interval. The Activity Measure for Post-Acute Care (AM-PAC) tool was used to assess the immediate postoperative function.Aims
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