Primary hip and knee joint replacements in Canada have been estimated to cost over $1.4 billion dollars annually, with revision surgery costing $177 million. The most common cause of revision arthroplasty surgery in Canada is infection. Periprosthetic joint infections (PJIs) are a devastating though preventable complication following arthroplasty. Though variably used, antibiotic laden bone cement (ALBC) has been demonstrated to decrease PJIs following primary total knee arthroplasty (TKA). Unfortunately, ALBC is costlier than regular bone cement (RBC). Therefore, the aim of this study was to determine if the routine use of ALBC in primary TKA surgery is a cost-effective practice from the perspective of the Canadian healthcare system. A decision tree was constructed using a decision analysis software (TreeAge Software, Williamstown, Massachusetts) to a two-year time horizon comparing primary TKA with either ALBC or RBC from the perspective of a single-payer healthcare system. All costs were in 2020 Canadian dollars. Health utilities were in the form of quality adjusted life years (QALYs). Model inputs for cost were derived from regional and national databases. Health utilities and probability parameters were derived from the latest literature. One-way deterministic sensitivity analysis was performed on all model parameters. The primary outcome of this analysis was an incremental cost-effectiveness ratio (ICER) with a willingness-to-pay (WTP) threshold of $50,000 per QALY. Primary TKA with ALBC (TKA-ALBC) was found to be more cost-effective compared to primary TKA with RBC (TKA-RBC). More specifically, TKA-ALBC dominated TKA-RBC as it was less costly on the long term ($11,160 vs. $11,118), while providing the same QALY (1.66). The ICER of this cost-utility analysis (CUA) was $-11,049.72 per QALY, much less than the WTP threshold of $50,000 per QALY. The model was sensitive to costs of ALBC-TKA as well as the probability of PJI following ALBC-TKA and RBC-TKA. ALBC ceased to be cost effective once the cost of ALBC was greater than $223.08 CAD per bag of cement. The routine use of ALBC in primary TKA is a cost-effective practice in the context of the Canadian healthcare system as long as the cost of ALBC is maintained at a reasonable price and the published studies to-date keep supporting the efficacy of ALBC in decreasing PJI following primary TKA. Further, this analysis is very conservative, and ALBC is likely much more cost-effective than presented. This is due to this model's revision surgery cost parameter being based on the average cost of all revision TKA surgery in Canada, regardless of etiology. Considering many PJIs require two-stage revisions, the cost parameter used in this analysis for revision surgery is an underestimate of true cost. Ultimately, this is the first cost-effectiveness study evaluating this topic from the perspective of the Canadian healthcare system and can inform future national guidelines on the subject matter

The aim of this study was to determine the incidence, annual trend, perioperative outcomes, and identify risk factors of early-onset (≤ 90 days) deep surgical site infection (SSI) following primary total knee arthroplasty (TKA) for osteoarthritis. Risk factors for early-onset deep SSI were assessed. We performed a retrospective population-based cohort study using prospectively collected patient-level data from several provincial administrative data repositories between January 2013, and March 2020. The diagnosis of early-onset deep SSI was based on published Centre for Disease Control/National Healthcare Safety Network (CDC/NHSN) definitions. The Mann-Kendall Trend Test was used to detect monotonic trends in early-onset deep SSI rates over time. The effects of various patient and surgical risk factors for early-onset deep SSI were analyzed using multiple logistic regression. Secondary outcomes were 90-day mortality and 90-day readmission. A total of 20,580 patients underwent primary TKA for osteoarthritis. Forty patients had a confirmed deep SSI within 90-days of surgery representing a cumulative incidence of 0.19%. The annual infection rate did not change over the 7-year study period (p = 0.879). Risk factors associated with early-onset deep SSI included blood transfusions (OR, 3.93 [95% CI 1.34-9.20]; p=0.004), drug or alcohol abuse (OR, 4.91 [95% CI 1.85-10.93]; p<0.001), and surgeon volume less than 30 TKA per year (OR, 4.45 [1.07-12.43]; p=0.013). Early-onset deep SSI was not associated with 90-days mortality (OR, 11.68 [0.09-90-58]; p=0.217), but was associated with an increased chance of 90-day readmission (OR, 50.78 [26.47-102.02]; p<0.001). This study establishes a reliable baseline infection rate for early-onset deep SSI after TKA for osteoarthritis through the use of a robust methodological process. Several risk factors for early-onset deep SSI are potentially modifiable or can be optimized prior to surgery and be effective in reducing the incidence of early-onset SSI. This could guide the formulation of provincial screening programs and identify patients at high risk for SSI

The optimum indications for debridement, antibiotics and implant retention (DAIR) are unclear. Previous studies have demonstrated higher success rate of DAIR within one year of the primary arthroplasty. This study aimed to compare the success rate of DAIR vs revision in “early” and “late” infections to provide guidance for clinical decision making. The Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort prospectively recorded PJIs between July 2014 and December 2017 in 27 hospitals. This study included PIANO patients with first time PJIs occurring after primary TKA. Treatment success was defined as the patient being alive, free from further revision and without clinical or microbiological evidence of reinfection at two years follow-up. “Early” and “late” infections were analyzed separately. Univariate analysis compared demographic and disease specific factors between the DAIR and Revision groups. Multivariate binary logistic regression identified whether treatment strategy and other risk factors were associated with treatment success in “early” and “late” infections. In 117 “early” (<1 year) infections, treatment success rate was 56% in the DAIR group and 54% in the revision group (p=0.878). No independent risk factors were associated with treatment outcome on multivariate analysis. In 134 “late” (>1 year) infections, treatment success rate was 34.4% in the DAIR group and 60.5% in the revision group (OR 3.07 p=0.006). On multivariate analysis, revision was associated with 2.47x higher odds of success (p=0.041) when compared to DAIR, patients with at least one significant co-morbidity (OR 2.27, p=0.045) or with Staphylococcus aureus PJIs (OR 2.5, p=0.042) had higher odds of failure. In “late” PJIs occurring >1 year following primary TKA, treatment strategy with revision rather than DAIR was associated with greater success. Patients with significant comorbidities and Staphylococcus aureus PJIs were at higher risk of failure regardless of treatment strategy

This study aimed to identify the success rate of debridement, antibiotics and implant retention (DAIR) for prosthetic joint infection (PJI) in a large prospective cohort of patients undergoing total knee arthroplasty (TKA). The ability for different PJI classification systems to predict DAIR success was assessed. A prospective, multicenter study of PJIs occurring between July 2014 and December 2017 in 27 hospitals across Australia and New Zealand was performed. First time PJIs following primary TKA that were managed with DAIR were analyzed. DAIR success was defined as the patient being alive with documented absence of clinical or microbiological evidence of infection and no ongoing antibiotics for the index joint at 2-year follow-up. Multivariate analysis was performed for multiple PJI classification systems to assess their ability to predict DAIR success using their respective definitions of “early” PJI (Coventry ≤1 month, International Consensus Meeting ≤90 days or Auckland <1 year), or as hematogenous versus chronic PJI (Tsukayama). 189 PJIs were managed with DAIR, with an overall success rate of 45% (85/189). Early PJIs had a higher rate of DAIR success when analyzed according to the Coventry system (adjusted odds ratio = 3.85, p = 0.008), the ICM system (adjusted odds ratio = 3.08, p = 0.005) and the Auckland system (adjusted odds ratio = 2.60, p = 0.01). DAIR success was lower in both hematogenous (adjusted odds ratio = 0.36, p = 0.034) and chronic PJIs (adjusted odds ratio = 0.14, p = 0.003) occurring more than one year since the primary TKA. DAIR success is highest when performed in infections occurring within one year of the primary TKA. Late infections had a high DAIR failure rate irrespective of their classification as hematogenous or chronic. Time since primary is a useful predictor of DAIR success

Surgical fixation of tibial plateau fractures in elderly patients with open reduction and internal fixation (ORIF) provides inferior outcomes compared to younger patients. Primary total knee arthroplasty (TKA) may be of benefit in patients with pre-existing arthritis, marked osteopenia, or severe fracture comminution. Rationale for primary TKA includes allowing early mobility in hopes of reducing associated complications such as deconditioning, postoperative pneumonia, or venous thromboembolism, and reducing post-traumatic arthritis which occurs in 25% to 45% of patients and requires revision TKA in up to 15%. Subsequent revision TKA has been shown to have significantly worse outcomes than TKA for primary osteoarthritis. This systematic review sought to elicit the clinical outcomes and peri-operative complication rates following primary TKA for tibial plateau fractures. A comprehensive search of MEDLINE, Embase, and PubMed databases from inception through March 2018 was performed in accordance with PRISMA guidelines. Two reviewers independently screened papers for inclusion and identified studies featuring perioperative complications and clinical outcomes following primary TKA for tibial plateau fractures. Studies were included for final data analysis if they met the following criteria: (1) studies investigating TKA as the initial treatment for tibial plateau fractures, (2) patients must be ≥ 18 years old, (3) have a minimum ≥ 24-month follow-up, and (4) must be published in the English language. Case series, cohort, case-control, and randomized-control trials were included. Weighted means and standard deviations are presented for each outcome. Seven articles (105 patients) were eligible for inclusion. The mean age was 73 years and average follow-up was 39 months. All-cause mortality was 4.75% ± 4.85. The total complication rate was 15.2% ± 17.3% and a total of eight patients required revision surgery. Regarding functional outcomes, the Knee Society score was most commonly reported. The average score on the knee subsection was 85.6 ± 5.5 while the average function subscore was 64.6 ± 13.7. Average range of motion at final follow-up was 107.5° ± 10°. Total knee arthroplasty for the treatment of acute tibial plateau fractures is enticing to allow early mobility and weightbearing. However, complication rates remain high. Functional outcomes are similar to patients treated with ORIF or delayed arthroplasty. Given these findings, surgeons should be highly selective in performing TKA for the immediate treatment of tibial plateau fractures

Constrained implants with intra-medullary fixation are expedient for complex TKA. Constraint is associated with loosening, but can correction of deformity mitigate risk of loosening?. Primary TKA's with a non-linked constrained prosthesis from 2010-2018 were identified. Indications were ligamentous instability or intra-medullary fixation to bypass stress risers. All included fully cemented 30mm stem extensions on tibia and femur. If soft tissue stability was achieved, a posterior stabilized (PS) tibial insert was selected. Pre and post TKA full length radiographs showed. i. hip-knee-ankle angles (HKAA). ii. Kennedy Zone (KZ) where hip to ankle vector crosses knee joint. 77 TKA's in 68 patients, average age 69.3 years (41-89.5) with OA (65%) post-trauma (24.5%) and inflammatory arthropathy (10.5%). Pre-op radiographs (62 knees) showed varus in 37.0%. (HKAA: 4. o. -29. o. ), valgus in 59.6% (HKAA range 8. o. -41. o. ) and 2 knees in neutral. 13 cases deceased within 2 years were excluded. Six with 2 year follow up pending have not been revised. Mean follow-up is 6.1 yrs (2.4-11.9yrs). Long post-op radiographs showed 34 (57.6%) in central KZ (HKKA 180. o. +/- 2. o. ). . Thirteen (22.0%) were in mechanical varus (HKAA 3. o. -15. o. ) and 12 (20.3%) in mechanical valgus: HKAA (171. o. -178. o. ). Three failed with infection; 2 after ORIF and one with BMI>50. The greatest post op varus suffered peri-prosthetic fracture. There was no aseptic loosening or instability. Only full-length radiographs accurately measure alignment and very few similar studies exist. No cases failed by loosening or instability, but PPF followed persistent malalignment. Infection complicated prior ORIF and elevated BMI. This does not endorse indiscriminate use of mechanically constrained knee prostheses. Lower demand patients with complex arthropathy, especially severe deformity, benefit from fully cemented, non-linked constrained prostheses, with intra-medullary fixation. Hinges are not necessarily indicated, and rotational constraint does not lead to loosening

Aim. There is controversy regarding the use of Antibiotic-loaded cement (ALBC) as compared to non-antibiotic-loaded cement (NALBC) to reduce the overall infection rate without affecting implant survival or adding additional risks on fixation for primary total knee arthroplasty (TKA). Method. To conduct the analysis, we utilized the Catalan Arthroplasty Registry (RACat) for the TKAs implanted between 2005 and 2017. The primary variable recorded was the use of cement with or without antibiotics. Other recorded variables included were age, sex, diabetes mellitus, obesity, Charlson index and type of hospital. We analyzed the effect of ALBC vs. NALBC in reducing the risk of prosthetic infection at 3, 6, 12, and 24 months as well as prosthetic survival due to mechanical causes at 1, 5, and 10 years. Univariate and multivariable analyses of risk factors were conducted. Thereby, an interactive predictive model that determines the risk of prosthetic infection based on each patient's characteristics was created. Results. A total of 28,287 TKAs from the RACat were analyzed. In that total, there were 19,788 NALBC and 8,499 ALBC. The infection rates for TKAs with NALBC vs. those with ALBC at 3, 6, 12, and 24 months were respectively: 1.69% vs. 1.39% (p=0.132); 1.81% vs. 1.56% (p=0.147); 2.14% vs. 1.73% (p=0.030); 2.51% vs. 1.86% (p=0.001). A statistically significant reduction in periprosthetic infection rate was observed in the ALBC group at 12 and 24 months. No differences were observed between the two groups in terms of prosthetic mechanical survival. Being younger, male and having had previous knee surgery or having a high comorbidity index all led to a higher risk of prosthetic revision due to infection. Conclusions. The use of ALBC as a fixation method for TKA leads to a reduction in the risk of prosthetic infection without altering the mechanical survival of the implant. The creation of a predictive model helps determine the individualized risk of prosthetic infection based on the patient's characteristics

Injection before total knee arthroplasty(TKA) is the one of the postoprative risk factors after TKA and Infection after TKA can result in disastrous consequences. When the duration between injection and TKA is longer than 6 months, the risk is no longer elevated. Evaluation of synovial WBC number in frozen section slide is needed to check the presence of infection in revision total knee arthroplasty. Currently many patients have a history of multiple intraarticular injection before the primary TKA. Purpose of this study is to evaluate the synovial WBC findings in primary TKA and compare between injection group and no injection group. Materials and Methods. The synovial specimen(suprapatella pouch and posterior capsule) of 68 primary total knee arthroplasty were evaluated by the pathologist and reported the number of the WBC in frozen section /5 separate high power fields(HPF) (500x).. Injection group were 37 cases and non -injection group were 31 cases. Preoperative CRP and ESR were recorded and followe-up duration was more than 2 years. Joint fluid was sent to be cultured and analysed. Results. WBC count in frozen section shoed was average 4 WBCs/HPF (range < 0∼ 25) in both specimen and the suprapatella specimen was 3 WBCs/HPW (range 0∼25) and posterior capsule specimen was 1 WBCs/HPF(range 0∼14). The WBC count of injection group was 8 (range, 0∼25) and that of no injection group was 1.2 cells (range 0∼12) (p<0.05). The WBC counts in joint fluid was average 240 cells/ml (range. 1∼300) in non injection group and 643 cells/ml(range, 50∼1000) (p<0.05). The duration from the intraarticular injection to index surgery was 9 months(range, 6 weeks∼ 7 momths). The number of injection and duration bwtween injection and operationto has no significant correlation with the WBC counts. Eight percentage of specimen showed more than 10 WBCs in injection group and these patients have been not infected after more than 24 moths after TKA. Conclusion. The WBC count of the synovium in priamry TKA with injection history for degenerative osteoarthritis is variable and we could not recommend the routine frozen section analysis in primary TKA who have a history of intraarticualr injection

Background. The management of the patella during primary total knee arthroplasty (TKA) is controversial. Despite the majority of patients reporting excellent outcomes following TKA, a common complaint is anterior knee pain. Resurfacing of the patella at the time of initial surgery has been proposed as a means of preventing anterior knee pain, however current evidence, including four recent meta-analyses, has failed to show clear superiority of patellar resurfacing. Therefore, the purpose of this study was to estimate the cost-effectiveness of patellar resurfacing compared to non-resurfacing in TKA. Methods. We conducted a cost-effectiveness analysis using a decision analytic model to represent a hypothetical patient cohort undergoing primary TKA. Each patient will receive a TKA either with the Patella Resurfaced or Not Resurfaced. Following surgery, patients can transition to one of three chronic health states: 1) Well Post-operative, 2) Patellofemoral Pain (PFP), or 3) Serious Adverse Event (AE), which we have defined as any event requiring Revision TKA, including: loosening/lysis, infection, instability, or fracture (Figure 1). We obtained revision rates following TKA for both resurfaced and unresurfaced cohorts using data from the 2014 Australian Registry. This data was chosen due to similarities between Australian and North American practice patterns and patient demographics, as well as the availability of longer term follow up data, up to 14 years postoperative. Our effectiveness outcome for the model was the quality-adjusted life year (QALY). We used utility scores obtained from the literature to calculate QALYs for each health state. Direct procedure costs were obtained from our institution's case costing department, and the billing fees for each procedure. We estimated cost-effectiveness from a Canadian publicly funded health care system perspective. All costs and quality of life outcomes were discounted at a rate of 5%. All costs are presented in 2015 Canadian dollars. Results. Our cost-effectiveness analysis suggests that TKA with patella resurfacing is a dominant procedure. Patients who receive primary TKA with non-resurfaced patella had higher associated costs over the first 14 years postoperative ($16,182 vs $15,720), and slightly lower quality of life (5.37 QALYs vs 6.01 QALYs). The revision rate for patellar resurfacing was 1.3%. If the rate of secondary resurfacing procedures is 0.5% or less, there is no difference in costs between the two procedures. Discussion. Our results suggest that, up to 14 years postoperative, resurfacing the patella in primary TKA is cost-effective compared to primary TKA without patellar resurfacing, due to the higher revision rate in this cohort of patients for secondary resurfacing. Our sensitivity analysis suggests that, among surgical practices that do not routinely perform secondary resurfacing procedures (estimated rate at our institution is 0.3%) there is no significant difference in costs. Although our results suggest that patella resurfacing results in higher quality of life, our model is limited by the availability and validity of utility outcome estimates reported in the literature for the long term follow up of patients following TKA with or without patella resurfacing and secondary resurfacing procedures

In primary TKA, non- or semi-constrained TKA implants might have their limitations in the absence of collateral ligaments, severe deformity, large osseous defects and gross flexion-extension instability. Although most primary TKA indications can be solved with modular, non-hinged implants, an adequate balancing might require a relevant soft tissue release. This consequently adds complexity and operative time with less predictable results in the elderly patient. The current literature reporting on short- to mid-term results of rotating hinged implants in primary osteoarthritis shows some quite diverse results and consequently different interpretations of this implant type in primary knee arthroplasty. Although some authors were able to show good and excellent clinical results in 91% of patients and consequent survival rates of a rotating hinge implant after 15 years up to 96% in primary indications, others found high complication rates of up to 25% of all operated patients, which remains unclear for us and is inconsistent with our clinical results in primary and revision TKA in over 30 years of experience with the ENDO-Model rotating hinge implant. Our potential indications in the elderly for a rotating or pure hinged implant in primary TKA include: Complete MCL instability; Severe varus or valgus deformity (>20 degrees) with necessary relevant soft tissue release; Relevant bone loss including insertions of collaterals; Gross flexion-extension gap imbalance; Ankylosis; One staged implantation with specific antibiotics after PJI. Due to general limited soft tissues or hyperlaxity, patients with neuropathic joints, or lack of extensor mechanism should be considered for a complete hinged implant. The ENDO-model hinge has only been minimally adapted since its development in the 70´s, including fully cemented long stems, in modular and non-modular versions. We strictly reserve a rotational hinge in primary indications for patients >70 years with a combined varus alignment, whereas in severe valgus deformities, a complete hinged implant version should be used for our implant design

Introduction. Wound condition after primary total knee arthroplasty (TKA) is important for prevention of periprosthetic infection. Any delay in wound healing will cause deep infection, which leads to the arthroplasty failure. Prevention of soft tissue problems is thus essential to achieve excellent clinical results. However, it is unknown as to the important surgical factors affecting the wound healing using detailed wound score after primary TKA so far. It was hypothesized that operative technique would affect wound healing in primary TKA. The purpose of the present study was to investigate and to clarify the important surgical factors affecting wound score after primary TKA. Methods. A total of 139 knees in 128 patients (mean 73 years) were enrolled. All primary TKAs were done by single surgeon. All patients underwent unilateral or bilateral TKA using Balanced Knee System®, posterior stabilized (PS) design (Ortho Development, Draper, UT) or Legion®, PS design (Smith and Nephew, Memphis, TN) under general and/or epidural anesthesia. Patients with immunosuppressive therapy, hypokalemia, poor nutrition (albumin < 3.4 g/dL), diverticulosis, infection elsewhere, uncontrolled diabetes mellitus (HbA1C>7.0%), obesity (Body Mass Index > 35 kg/m2), smoking, renal failure, hypothyroidism, alcohol abuse, rheumatoid arthritis, posttraumatic arthritis, and previous knee surgery were excluded. Hollander Wound Evaluation Score (HWES) was assessed on postoperative day 14. We evaluated age, sex, body mass index, HbA1C (%), preoperative femorotibial angle (FTA) on plain radiograph. In addition, intraoperative patella eversion, intraoperative anterior translation of the tibia, patella resurfacing, surgical time, tourniquet time, unidirectional barbed suture and length of skin incision were also evaluated as surgical factors. Multiple regression analysis was done using stepwise method to identify the surgical factors affecting HWES. Results. Detailed demographic data was presented in Table 1. The average HWES was 5.0 ± 0.8 point. As to the distribution of the HWES, data was shown in Figure 1. Namely, HWES was 3 point in 5 cases, 4 in 29 cases, 5 in 63 cases, and 6 in 42 cases. As any adverse events were not found in each TKA, there were no cases requiring debridement and re-closure of the wound after primary TKA. According to stepwise forward regression test, intraoperative patella eversion and anterior translation of the tibia were entered in this model, while age, Sex, BMI, HbA1C, FTA, surgical time, tourniquet time, patella resurfacing, unidirectional barbed suture and length of skin incision were not entered in the model. The multiple regression analysis in the current study would show the appropriate results, as Durbin-Watson ratio was 1.762. Standardized partial regression coefficient was as follows; 0.57 in anterior translation of the tibia, 0.38 in patella eversion (Table 2). Discussion. The results of the present study would support out hypothesis that operative technique would affect wound healing in primary TKA. Specifically, intraoperative patella eversion and anterior translation of the tibia should be avoided for quality cosmesis of the wound healing in primary TKA. To view tables/figures, please contact authors directly

Total Knee Arthroplasty (TKA) patients may present with effusion, pain, stiffness and functional impairment. A positive metal hypersensitivity (positive LTT) may be an indication for a revision surgery with a custom-made implant devoid of any hypersensitivity-related metal or an implant with the least possible ion content of the metal hypersensitivity, if no custom-made is available. The purpose of the current study is to assess the prevalence of metal hypersensitivity in subjects requiring a primary TKA and assess their early functional outcomes. We are recruiting 660 subjects admitted for TKA. Subjects are randomly assigned to 2 groups: oxidized zirconium implant group or cobalt-chrome implant group. Functional outcomes and quality of life (QoL) are measured pre operatively, 3, 6 and 12 months post operatively with WHOQOL-BREF (domain1-Physical Health, domain 2- Psychological, domain 3- Social relationships, domain 4-Environment), KSS, KOOS and pain Visual Analog Scale (VAS). LTT and metal ions are evaluated pre operatively and 12 months post-surgery. One hundred-sixty patients, 98 women, were enrolled in the study. Mean age was 65.6±8.9. Mean follow up (FU) was 7.1±3.8 months. Eighty-one (50.6%) were randomised in the cobalt-chrome group. Infection rate was 1.9%, one patient required debridement. Three patients (1.9%) presented with contracture at three months FU. At 12 months, WHOQOL-BREF domain 1, 2 and 4 improved significantly (p0,05). Overall, all 160 patients improved their functional outcomes and QoL. At 12 months, VAS scores decreased from 7±2.06 at baseline to 1.95±2.79. Furthermore, the high prevalence of positive LTT (27/65) do not seem to affect early functional outcomes and QoL on patients that may have received a potential implant with hypersensitivity (18/27)

Post-operative swelling and wound ooze following primary Total Knee Replacement (TKR) can lead to complications such as wound infection, and delays in achieving adequate range of motion. The aim of the study is to examine the effectiveness of using an additional layer of a self-adherent elastic wrap (CobanTM) in reducing post-operative swelling and wound ooze after Primary TKR. Seventeen pairs of patients who had had a primary TKR were studied in a prospective, age and gender-matched cohort study. Half of the patients had wool and crepe dressing (Group A) and the other half with an additional layer of CobanTM dressing (Group B), applied to the wound. Limb circumference was measured at three levels (below knee, knee and above knee) preoperatively and 3 consecutive days post-operatively. The area of wound ooze was measured using AutoCAD software. Group B showed a significant reduction difference in the mean of post-operative limb circumference at above knee level (3.2 vs 4.9 cm. p =0.023). This trend in reduction was seen at below knee and knee levels, though not statistically significant. There is a clinical difference in the wound ooze measured area of 17.8cm2 Vs 22.9 cm2, in Group B and A, respectively. Within the relative small size of this study, there appeared a significant reduction in post-operative limb swelling and wound ooze when using CobanTM in TKR. It is promising preliminary results, however the study groups must be extended

Purpose. This meta-analysis was designed to compare the effectiveness and safety of intravenous (IV) versus topical administration of tranexamic acid (TXA) in patients undergoing primary total knee arthroplasty (TKA) by evaluating the need for allogenic blood transfusion, incidence of postoperative complications, volume of postoperative blood loss, and change in hemoglobin levels. Materials and Methods. Studies were included in this meta-analysis if they assessed the allogenic blood transfusion rate, postoperative complications including pulmonary thromboembolism (PTE) or deep vein thrombosis (DVT), volume of postoperative blood loss via drainage, estimated blood loss, total blood loss, and change in hemoglobin before and after surgery in primary TKA with TXA administered through both the intravenous (IV) and topical routes.[Fig. 1]. Results. Ten studies were included in this meta-analysis.[Fig. 2] The proportion of patients requiring allogenic blood transfusion (OR 1.34, 95% CI: 0.63 to 2.81; P=0.45) [Fig. 3] and the proportion of patients who developed postoperative complications including PTE or DVT (OR 0.85, 95% CI: 0.41 to 1.77; P=0.66) did not significantly differ between the two groups. There was 52.3 mL less blood loss via drainage (95% CI: −50.74 to 185.66 ml; P=0.44),[Fig. 4] 21.5 mL greater estimated blood loss (95% CI: −98.05 to 55.12 ml; P=0.32), and 51.4 mL greater total blood loss (95% CI: −208.16 to 105.31 ml; P=0.52) [Fig. 5]in the topical TXA group as compared to the IV TXA group. The two groups were also similar in terms of the change in hemoglobin levels (0.02 g/dl, 95% CI: −0.36 to 0.39 g/dl; P=0.94). Conclusion. In primary TKA, there are no significant differences in the transfusion requirement, postoperative complications, blood loss, and change in hemoglobin levels between the intravenous and topical administration of TXA. For figures/tables, please contact authors directly.

Background. Total knee arthroplasty (TKA) is offered to patients who have end-stage knee osteoarthritis to reduce pain and improve functional performance. Knee edema and pain deteriorate the patients' outcomes after TKA at early period. By quantifying the patients' early outcome deficits and their potential relationships to edema and pain may assist in the design of in-patient rehabilitation programs. Objectives. The aim of this study was to investigate of the effect of knee swelling on early patients' outcomes after primary TKA. Design and Methods. The study group consisted of 61 patients (10 males, 51 females), who underwent primary TKR because of knee arthrosis were included in the study with mean age 65.2±9 years. Patients were evaluated regarding knee circumference (10 cm superior of midpoint of patella, midpoint of patella, 10 cm distal of midpoint of patella), pain (Numeric Pain Rating Scale (NPRS)), knee range of motion (ROM), the day of active straight leg raise, knee function score (Hospital for Special Surgery (HSS)), Functional activities were evaluated using the Iowa Level of Assistance Scale (ILAS) and walking speed was evaluated using the Iowa Ambulation Velocity Scale (IAVS). Results. There were moderate significant correlation between knee circumference (10 cm superior of midpoint of patella; r=0.328, p=0.001, midpoint of patella; r=0.310, p=0.002, 10 cm distal of midpoint of patella; r=0.300, p=0.003) and IAVS. While, significant low correlation was found between pain level and knee ROM (r=−0.272, p=0.008), there was strong significant correlation between pain level and HSS (r=0.866, p<0.001). There was not significant correlation between knee swelling and all the other measurement, and also between pain and all the other measurement (p>0.05). Conclusion. The moderate correlation between knee swelling and IVAS, low correlation between pain and knee ROM, and also strong correlation between pain and HSS suggests that improved postoperative knee swelling and pain could be important to enhance the potential benefits of TKA in early stage. With improvement in knee swelling and pain the patient may obtain good functional outcomes and knee score

Introduction. The constitutional knee anatomy in the coronal plane includes the distal femoral joint line obliquity (DFJLO) which in most patients is in slight valgus positioning. Despite this native anatomy, the mechanical positioning of the femoral component during primary total knee arthroplasty (TKA) often ignores the native DFJLO opting to place the femur in a set degree of valgus that varies upon the practitioner's practice and experience. Unfortunately, this technique is likely to generate high rate of distal lateral femoral overstuffing. This anatomical mismatch might be a cause of anterior knee pain and therefore partly explain the adverse functional outcomes of mechanically aligned (MA) TKA. Our study aims at assessing the relationship between constitutional knee anatomy and clinical outcomes of MA TKA. We hypothesized that a negative relationship would be found between the constitutional frontal knee deformity, the distal femoral joint line obliquity, and functional outcomes of MA TKA with a special emphasize on patellofemoral (PF) specific outcomes. Methods. One hundred and thirteen patients underwent MA TKA (posterior-stabilized design) for primary end-stage knee osteoarthritis. They were prospectively followed for one year using the New KSS 2011 and HSS Patella score. Residual anterior knee pain was also assessed. Knee phenotypes using anatomical parameters (such as HKA, HKS, DFJLO and LDFA (Lateral distal femoral angle)) were measured from preoperative and postoperative lower-limb EOS® images (Biospace, Paris, France). We assessed the relationship between the knee anatomical parameters and the functional outcome scores at 1 year postoperatively. Results. We investigated four groups according to the preoperative obliquity of the distal femur and HKA. The group with high DFJLO and varus knee deformity demonstrated lower HSS scores (drop>10%, p=0.03) and higher rate of anterior knee pain (p=0.03). Higher postoperative variation of LDFA was associated with lower HSS scores (r = −0.2367, p=0.03) and with higher preoperative DFJLO (p=0.0001) due to the MA technique. Knee phenotypes with LDFA<87° presented higher risk of variation of LDFA. No correlation was found using New KSS 2011 outcomes at one-year follow-up. Discussion/Conclusion. Disregard of the constitutional knee anatomy (LDFA and DFJLO) when performing a MA TKA may generate a non-physiologic knee kinematics that impact patellofemoral outcomes and resulting in residual anterior knee pain. While these results are restricted to modern posterior-stabilized TKA design, recent in silico and in vitro studies supported the negative effect of the lateral overstuffing of the femoral component in the coronal plane during knee flexion. This study provides further evidence that suggest patient-specific anatomical considerations are needed to optimize component position and subsequent outcomes following primary TKA. Additional studies are needed to integrate the rotational status of the femoral component in this analysis. For any figures or tables, please contact authors directly

Purpose. The purpose of this study was to compare the outcomes and complications of normal weight, class one obese (BMI=30-34.9 kg/m2) and superobese (BMI≥50 kg/m2) primary total knee replacement (TKR) patients. Method. Between January 1995 and December 2005, 4104 primary TKR were performed in our centre. Patients were stratified for their obesity level according the World Health Organisation (WHO) and current surgical literature classification. Sixty-seven superobese patients (group one) were identified. They were matched with normal weight (group two) and class one obese (group three) primary TKR patients for sex, age, side, preoperative diagnosis, implants used, time since surgery and preoperative SF-12 mental component summary score (MCS). Patient clinical outcomes (WOMAC, SF-12 and Knee Society scores), radiographs, complications, readmissions, and revisions rates were compared for normal BMI, class one obese and superobese patients. Results. The mean BMI of our primary TKR patients was 32,6. Using the WHO BMI classification, 0.3% were underweight, 10.4% normal weight, 30.1 % overweight, 31.0 % class 1 obesity, 16.5 % class 2 obesity, 9.8 % class 3 obesity and 1.9 % superobese. Superobese population (n=67) was 61.59.2 yo, with sex ratio at 5.1 (F=56;M=11), preoperative SF-12 MCS at 52.610.6. Their preoperative diagnosis was osteoarthritis (n=62) or inflammatory arthritis (n=5). All groups were equal (n=67) and were similar for these characteristics. Mean clinical and radiographic follow-up was 7.33.2 yrs. Superobese patients presented lower preoperative SF-12 physical component summary (PCS; gp 1=26.05.6; gp 2=29.68.4; gp 3=30.57.8; p<0.05), Knee Society score (gp 1=73.626.4; gp 2=84.926.5; gp 3=88.517.4; p<0.05) and WOMAC scores (gp 1=35.814.5; gp 2=44.116.7; gp 3=41.315.7; p<0.05). However the three groups presented a similar improvement of the SF-12 PCS (gp1=10.512.0; gp2= 6.810.9; gp3=6.812.1; p= 0.22) and Knee Society score (gp1=81.930.8; gp 2= 74.220.9; gp 3=78.729.9; p= 0.21). The superobese patients group had a significantly longer hospital stay, higher complication rate, and were more frequently re-admitted to hospital and submitted to revision surgery. Conclusion. Superobese patients can enjoy comparable clinical outcomes when compared to patients with lower BMIs, but do run increased risks in terms of a complication and a greater hospital re-admission rate

In primary TKA, non- or semi-constraint TKA implants might have their limitations in the absence of collateral ligaments, severe deformity, large osseous defects and gross flexion - extension instability. Although most primary TKA indications can be solved with modular, non-hinged implants, an adequate balancing might require a relevant soft tissue release. This consequently adds complexity and operative time with less predictable results in the elderly patient. The current literature reporting on short to mid-term results of rotating hinged implants in primary osteoarthritis shows some quite diverse results and consequently different interpretations of this implant type in primary knee arthroplasty. Although some authors were able to show good and excellent clinical results in 91% of patients and consequent survival rates of a rotating hinge implant after 15 years up to 96% in primary indications, others found high complication rates of up to 25% of all operated patients, which remains unclear for us and is inconsistent with our clinical results in primary and revision TKA in over 30 years of experience with the Endo-Model rotating hinge implant. Our potential indications in the elderly for a rotating- or pure-hinged implant in primary TKA include: Complete MCL instability, Severe varus or valgus deformity (>20 degrees) with necessary relevant soft tissue release, Relevant bone loss including insertions of collaterals, Gross flexion-extension gap imbalance, Ankylosis, One staged implantation with specific antibiotics after PJI. Due to general limited soft tissues or hyper laxity, patients with neuropathic joints, or lack of extensor mechanism should be considered to a complete hinged implant. The ENDO-model hinge has only been minimal adapted since its development in the 70's, including fully cemented long stems, in modular and non-modular versions. We strictly reserve a rotational hinge in primary indications for patients >70 years with a combined varus alignment, whereas in severe valgus deformities, a complete hinged implant version should be used for our implant design

Purpose. There is controversial whether synovectomy must be done in primary total knee arthroplasty (TKA). The objectivity of the study was to compare the effect of synovectomy on inflammation and clinical outcomes after surgical treatment of knee osteoarthritis. Methods. A total of 240 patients who underwent primary unilateral TKR were randomly divided into a group without (Group A) and with synovectomy (Group B). All operations were performed by the same surgeon and follow-up was for 4 year. Clinical outcomes (including American Knee Society score (AKS), SF-36, and HSS scores) serum inflammatory markers (including interleukin-6 (IL-6), CRP and ESR) and the difference in temperature of the affected knee skin, swelling, ROM, patients VAS satisfaction score and VAS pain score were sequentially evaluated until 4 years after surgery. Result. There were no statistically different clinical parameters between the two groups preoperatively. At the 4 years follow-up, both groups had a similarly significantly improved AKS clinical and functional score. Similar changes in serial inflammatory markers were identified in both groups. In addition, no difference was seen regarding drainage-fluid inflammatory markers at any follow-up time. There was no difference in respect to patients satisfaction score from surgery to 1 year, but Group B showed greater patients satisfaction score from 2 year to four year, with less number of patients suffering from anterior pain. There was no difference with regard to other parameters at any follow-up time. Conclusions. Synovectomy in primary TKA does not seem to have any clinical advantage and shorten the duration of the inflammatory response, but it might increase patient satisfaction score and reduce anterior knee pain

Introduction. Patellar resurfacing is performed in more than 90% of primary total knee arthroplasties (TKAs) in the United States, yet far fewer patellae are resurfaced internationally. Multiple randomized controlled trials have shown decreased revision rates in patients with resurfaced patellas (RP) vs. non-resurfaced (NR). However, most of these studies showed no difference in patient satisfaction, anterior knee pain, or knee society scores. (Figure 1) Given uncertain benefits, the purpose of this study was to determine if the rates of patellar resurfacing have changed over the past 10 years worldwide. Methods. Data was obtained via direct correspondence with registry administrators or abstracted from the annual reports of six national joint registries: Australia, Denmark, England, New Zealand, Norway, and Sweden. Rates of patellar resurfacing between 2003 and 2013 were collected. Where data was available, subgroup analysis was performed to examine revision rates among RP and NR TKAs. Results. The average rates of patellar resurfacing from 2003 to 2013 ranged from 5% (Norway) to 71% (Denmark). Three countries showed a decreased rate of patellar resurfacing over this time period while two demonstrated an increase. The largest decrease in resurfacing rates was in Sweden (15% to 2%), while the biggest increase was in Australia (44% to 53%). (Figure 2) In 2010, 48,367 of 137,813 (35%) primary TKAs from all six countries were resurfaced. (Figure 3) Among RP and NR TKAs, Australia documented a 10-year cumulative revision rate (CRR) of 4.9% and 6.0%, respectively. Sweden showed a 10-year CRR of 4% in both groups. Conclusion. While not all national joint registries report rates of patellar resurfacing, it is clear that most countries outside of the US continue to resurface a much smaller proportion of patellas in primary TKA. Worldwide, the rates of patellar resurfacing have changed little in the past decade