Primary total joint arthroplasty (TJA) is an increasingly common and safe way of treating joint disease. Robust preoperative assessment improved intraoperative techniques and holistic rehabilitation contribute to an uneventful postoperative period. Despite there being evidence against the utility of postoperative blood tests, it is still often part of routine practice. We aim to evaluate the usefulness of these tests by investigating their incidence following TJA as well as identifying preoperative risk factors for abnormal blood test results postoperatively especially pertaining to anaemia and acute kidney injury (AKI). This is a retrospective cohort study of patients who had elective TJA between January and December 2019 at a tertiary centre. An independent student's t-test and Fisher's exact test was used to compare variables between the normal and abnormal postoperative results groups. An analysis of variance (ANOVA) was performed to identify risk factors for an abnormal blood test result. Analyses of receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to determine cut off values that could be suggestive of abnormal test results postoperatively. The study included 2721 patients with a mean age of 69 of which 46.6% were males. Abnormal postoperative bloods were identified in 444 (16.3%) patients. We identified age (≥65 years), female gender, ASA ≥ 3 as risk factors for developing abnormal postoperative blood tests. Preoperative haemoglobin (≤ 127 g/dL), haematocrit (≤ 0.395L/L) and potassium (≤ 3.7 mmol/L) were noted as cut-offs that could be predictive of postoperative anaemia or AKI respectively. The costs outweigh the benefits of ordering routine postoperative blood tests in TJA patients. Clinicians should risk stratify their patients and have a lower threshold for ordering blood tests in patients with one or more of the risk factors we have identified. These risk factors are age (≥65 years), females, ASA ≥ 3, preoperative haemoglobin (≤ 127 g/L), haematocrit (≤ 0.395L/L), and potassium (≤ 3.7 mmol/L)

Background. Readmission following any total joint arthroplasty has become a closely watched metric for many hospitals in the United States because financial penalties imposed by CMS for excessive readmissions occurring within thirty days of discharge has occurred since 2015. The purpose of this study was to identify both preoperative comorbidities associated with and postoperative reasons for readmission within thirty days following primary total joint arthroplasty in the lower extremity. Methods. Retrospective data was collected for patients who underwent elective primary total hip arthroplasty (CPT code 27130), total knee arthroplasty (27447), and total ankle arthroplasty (27702) from January 1, 2008, to December 31, 2013 at our institution. The sample was separated into readmitted and non-readmitted cohorts. Demographic variables, preoperative comorbidities, Charlson Comorbidities Index (CCI), operative parameters, readmission rates, and causes of readmission were compared between the groups using univariate and multivariate regression analysis. Results. There were 42 (3.4%), 28 (2.2%), and 1 (0.5%) readmissions within 30 days for THA, TKA, and TAA, respectively. The most common cause of readmission within 30 days following total joint arthroplasty in lower extremity was infection. Trauma was the second most common reason for readmission of a THA while wound dehiscence was the second most common cause for readmission following TKA. With univariate regression, there were multiple associated factors for readmission among total hip and total knee arthroplasty patients including BMI, metabolic equivalent (MET), and CCI. Multivariate regression revealed that hospital length of stay was significantly associated with 30-day readmission after THA and TKA. Conclusion. Patient co-morbidities and pre-operative functional capacity significantly affect 30-day readmission rate following total joint arthroplasty. Adjustments for these parameters should be considered when hospital penalties are calculated with regard to 30-day readmission. Level of Evidence. Level III; Retrospective cohort study

Background. Readmission following any total joint arthroplasty has become a closely watched metric for many hospitals in the United States because financial penalties imposed by CMS for excessive readmissions occurring within thirty days of discharge will be forthcoming in 2015. The purpose of this study was to identify both preoperative comorbidities associated with and postoperative reasons for readmission within thirty days following primary total joint arthroplasty in the lower extremity. Methods. Retrospective data was collected for patients who underwent elective primary total hip arthroplasty (CPT code 27130), total knee arthroplasty (27447), and total ankle arthroplasty (27702) from January 1, 2008, to December 31, 2013 at our institution. The sample was separated into readmitted and non-readmitted cohorts. Demographic variables, preoperative comorbidities, Charlson Comorbidities Index (CCI), operative parameters, readmission rates, and causes of readmission were compared between the groups using univariate and multivariate regression analysis. Results. There were 42 (3.4%), 28 (2.2%), and 1 (0.5%) readmissions within 30 days for THA, TKA, and TAA, respectively. The most common cause of readmission within 30 days following total joint arthroplasty in lower extremity was infection. Trauma was the second most common reason for readmission of a THA while wound dehiscence was the second most common cause for readmission following TKA. With univariate regression, there were multiple associated factors for readmission among total hip and total knee arthroplasty patients including BMI, metabolic equivalent (MET), and CCI. Multivariate regression revealed that hospital length of stay was significantly associated with 30-day readmission after THA and TKA. Conclusion. Patient co-morbidities and pre-operative functional capacity significantly affect 30-day readmission rate following total joint arthroplasty. Adjustments for these parameters should be considered when hospital penalties are calculated with regard to 30-day readmission

Aim: To evaluate the benefits of suction drainage following primary total joint arthroplasty. Materials and Methods: A two year retrospective study was conducted on 126 consecutively selected patients who had primary total hip & knee replacements in a district general hospital. There were 63 patients (mean age 69 years) each in drain and non-drain groups. Sex distribution and anticoagulants use in both groups were similar. All patients underwent same operative technique and method of closure. Primary hip replacements were carried out by Hardinge approach and knee replacements by medial parapatellar approach. Results: Mean postoperative fall in haemoglobin was 3.2 and 3.3 gm/dl in the drain and nondrain groups respectively. Blood transfusion was required in 34 patients with drains and 28 patients without drains. Mean blood transfusion requirements in both the groups were between 2–3 units. There was no statistically significant difference between the two groups in postoperative complications such as hypotension and wound infections (all negative for microbiology culture). The average rehabilitation time in both the groups was 8–9 days. Statistical analysis showed no difference in postoperative fall of haemoglobin, blood transfusion and rehabilitation time between the two groups (p> 0.05). Conclusion: We concluded that the routine use of suction drain is unnecessary after an uncomplicated total joint arthroplasty

Aims

Prophylactic antibiotic regimens for elective primary total hip and knee arthroplasty vary widely across hospitals and trusts in the UK. This study aimed to identify antibiotic prophylaxis regimens currently in use for elective primary arthroplasty across the UK, establish variations in antibiotic prophylaxis regimens and their impact on the risk of periprosthetic joint infection (PJI) in the first-year post-index procedure, and evaluate adherence to current international consensus guidance.

Aims

We aim to evaluate the usefulness of postoperative blood tests by investigating the incidence of abnormal results following total joint replacement (TJR), as well as identifying preoperative risk factors for abnormal blood test results postoperatively, especially pertaining to anaemia and acute kidney injury (AKI).

Aim

Whether laminar airflow (LAF) in the operating room (OR) is effective for decreasing periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant yet controversial issue. This study investigated the association between operating room ventilation systems and the risk of PJI in TJA patients.

The brief answer is no….I do not believe that outpatient total joint arthroplasty is the emergent standard of care. However, for some patients and some surgeons I do believe that outpatient total joint arthroplasty can be performed safely and with greater comfort and convenience for the patient. Further, for the surgeon, it can provide greater control over the care environment if performed at an ambulatory surgery center.

Patient selection is paramount in my opinion for safely performing outpatient total joint arthroplasty. While some have attempted to define specific criteria, our own criteria include patients with simple orthopaedic problems who are healthy, trustworthy and have a good support system of family or friends to assist them.

As surgeons we must also be self-aware as the margin for error, particularly at a freestanding ambulatory surgery center, is narrow. Operative times should be reliably brief and blood loss should be minimal to allow for a safe discharge on the same day. Further the incidence of intraoperative complications such as fractures at the time of total hip arthroplasty or ligament injuries during total knee arthroplasty should be low. The surgeon should also be prepared with the equipment to address these common issues, if they do occur.

In our review of the NSQIP data set we matched 1,236 outpatient TJA 1:1 with inpatients based on propensity scores. The risk of 30-day readmissions and complications was no different between groups, although inpatients had a higher rate of VTE and outpatients had a higher risk of re-operation. Risk factors for adverse events included patient age > 85 years old, diabetes and BMI > 35. Likewise in a review of results from my own practice, we have seen no difference in the risk of complications.

As health care providers we must keep the safety of our patients paramount at all times. Further, we must be fiscally responsible to avoid costly complications, reoperations and readmissions. With conservative patient selection and careful surgical technique I believe that outpatient TJA offers an attractive alternative that is safe, cost effective and associated with high satisfaction for both patients and surgeons.

Patients undergoing Joint Arthroplasty received a significant proportion of blood transfusions. In this study, we compared the risk of Deep Infection, and Superficial Infection post operation following Primary Total Hip or Knee replacement in blood-transfused and non-blood-transfused patients.

Cohort of patients who underwent primary total Hip or Knee Arthroplasty from April 2012 to March 2015 in Alberta. Patient characteristics, comorbidity, received blood transfusion were collected from electronic medical records, operating room information systems, discharge abstract database, provincial clinical risk grouper data. Deep Infection and Superficial Infection were captured from Provincial Surgical Site Infection Surveillance data. Deep Infection include deep incisional and organ/space infections. Logistic regression analysis were used to compare Deep Infection and Superficial Infection in blood-transfused and non-blood-transfused cohorts, and risk-adjusted for age, gender, procedure type, and co-morbidities.

Our study cohort contains 27891 patients, with mean of age at admission was 66.3±10.4, 57.5% female, 49.3% had 1 or more comorbidities. 58.8% underwent Knee Replacement. 11.1% received blood transfusion during hospital stay (Total Hip Replacement (THR) =13.1% and Total Knee Replacement (TKR) =9.7%,). 1.1% had Deep Infection (THR=1.4% and TKR=0.9%) and 0.5% had Superficial Infection (THR=0.5% and TKR=0.5%). Blood-transfused patients got 1.7% Deep Infection and 1.0% Superficial infection. Non-blood-transfused patients got 1.0% Deep Infection and 0.5% Superficial infection. Controlling for age, gender, procedure type, and co-morbidities, the odds of Deep Infection were 1.6 times higher for blood-transfused patients than for non-blood-transfused patients (adjusted odds ratio [OR]=1.6, 95% confidence interval [CI] [1.2–2.2], p=0.004). The odds of Superficial Infection were 2.0 times higher for transfused patients (adjusted OR=2.0, 95% CI [1.3–3.0], p=0.002).

Blood transfusion increases Deep Infection and Superficial Infection post-surgery following Primary Total Knee or Hip Replacement. This finding suggests to reduce the unnecessary blood transfusion for patients considering Joint Arthroplasty. Reducing the blood transfusion will save the inpatient cost and decrease the infective complications post-surgery in Hip or Knee Arthroplasty patients.

Introduction

Alternative payment models, such as bundled payments, aim to control rising costs for total knee (TKA) and total hip arthroplasty (THA). Without risk adjustment for patients who may utilize more resources, concerns exist about patient selection and access to care. The purpose of this study was to determine whether lower socioeconomic status (SES) was associated with increased resource utilization following TKA and THA.

Aim

Perioperative hyperglycemia has many etiologies including medication, impaired glucose tolerance, uncontrolled diabetes mellitus (DM), or stress, the latter of which is common to post-surgical patients. This acute hyperglycemia may impair the ability of the host to combat infection.¹ Our study aims to investigate if post-operative day 1 (POD1) blood glucose level is associated with complications, including periprosthetic joint infection (PJI), after total joint arthroplasty (TJA) and to determine a threshold for glycemic control that surgeons should strive for during a patient's hospital stay.

Introduction

Peri-operative hyperglycemia has many etiologies, including medication, impaired glucose tolerance, uncontrolled diabetes mellitus (DM), or stress, the latter of which is common in post-surgical patients. Our study aims were to investigate if post-operative day 1 (POD1) blood glucose level was associated with post-operative complications after total joint arthroplasty (TJA), including periprosthetic joint infection (PJI), and to determine a threshold for glycemic control that surgeons should strive for during a patient's hospital stay.

Despite the prophylactic use of antibiotics and hygienic strategies, surgical site infection following total joint arthroplasty (TJA) is still a severe and unsolved complication. Since antibiotic-loaded bone cement (ALBC) was introduced by Buchholz in the 1970s, the use of ALBC has been increasingly used for the prevention and treatment of periprosthetic infection (PPI). However, the routine use of ALBC during primary TJA remains controversial. Recent clinical studies have found that ALBC is effective in reducing the risk of PJI following primary TJA. Although ALBC having the advantage of reducing the risk of PJI, the main disadvantages are the possible development of toxicity, antibiotic resistance, allergic reaction, and possible reduction of the mechanical properties of bone cement. Nevertheless, a recent published article demonstrated, that the use of high dose dual-antibiotic impregnated cement reduce significantly the rate of surgical site infections compared to standard low dose single ALBC in the setting of a hip fracture treating with hemiarthroplasty. Furthermore, Sanz-Ruiz et al. presented that the use of ALBC in TJA has favorable cost-efficiency profile. In this context, reasons why surgeons should use antibiotic-loaded bone cement during primary TJA are demonstrated.

Despite the demonstrated success in revision total joint arthroplasties, the utilization of antibiotic-loaded bone cement in primary total joint arthroplasty remains controversial. Multiple studies have demonstrated several risks associated with the routine use of this technique including: allergic reactions, changing the mechanical properties of the cement, emergence of resistant bacterial strains, systemic toxicity, and the added cost. In addition, evidence shows a currently low rate of periprosthetic joint infections in primary total joint arthroplasty (around 1%) and the theoretical benefit of marginally reducing this rate by using antibiotic-cement may not necessarily justify the associated risks and the added cost. Moreover, most of the primary total hip and an increasing number of primary total knee arthroplasties are cementless, which further raises questions about the routine use of antibiotic-loaded bone cement in primary total joint arthroplasty

Aim. Analysis of microbiological spectrum and resistance patterns as well as the clinical outcome of patients who underwent a Debridement, antibiotics and implant retention (DAIR) procedure in the early phase following failed two-stage exchange arthroplasty of the knee and hip. Method. Of 312 patients treated with two-stage exchange arthroplasty between January 2011 and December 2019, 16 (5.1%) patients (9 knee, 7 hip) underwent a DAIR procedure within 6 months following second stage. We retrospectively analyzed the microbiological results as well as changes in the microbiological spectrum and antibiotic resistance patterns between stages of two-stage exchange arthroplasties and DAIR procedures. Patient's re-revision rates after a minimum follow-up of 12 months following DAIR procedure were evaluated. Moreover, differences between knee and hip and between infected primary total joint replacement (TJRs) and infected revision TJRs as well as patient's host factors and microbiological results regarding the outcome of DAIR were analyzed. Results. In 7/16 (43.8%) patients the first and second stage procedure was culture positive, in 5/16 (31.2%) patients the first and second stage procedure was culture negative and in 4/16 (25%) patients the first stage procedure was culture positive, and the second stage procedure was culture negative. Moreover, 6 (37.5%) out of 16 DAIR procedures showed a positive microbiological result. In 5/7 (71.4%) patients with culture positive second stage procedure a different microorganism compared to first stage procedure was detected. In 6/6 (100%) patients with culture positive DAIR procedure, the isolated microorganisms were not detected during first or second stage procedure. An additional re-revision surgery was necessary in 4/16 (25%) patients after a median time of 31 months (range, 12 to 138 months) at a mean follow up of 63.1 ± 32 months following DAIR procedure. Highest re-revision rates were found in patients with culture positive second stage procedures (3/7 [42.9%]) and patients with culture positive DAIR procedures (2/6 [33.3%]). Conclusions. DAIR procedure seems to be a useful early treatment option following failed two-stage exchange arthroplasty. The re-revision rates were independent of different combinations of culture positive and culture negative first and second stage procedures. The high number of changes in the microbiological spectrum needs to be considered in the treatment of PJI

Introduction. Total joint arthroplasty (TJA) is projected to be the most common elective surgical procedure in the coming decades, however TJA now accounts for the largest expenditure per procedure for Medicare and Medicaid provided interventions. This is coupled with increasing complexity of surgical care and concerns about patient satisfaction. The Perioperative Surgical Home (PSH) model has been proposed as a method to both improve patient care and reduce costs. The PSH model provides evidence-based protocols and pathways from the time of surgical decision to after postoperative discharge. PSH pathways can further be standardized with integration into electronic medical records (EMRs). The purpose of this study is to see if the implementation of PSH with and without EMR integration effects patient outcomes and cost. Methods. A retrospective review was performed for all patients who underwent elective primary total joint arthroplasty at our institution from January 1, 2012 to April 1, 2018. Three cohorts were compared. The first cohort included patients before the implementation of the PSH model (January 1, 2012 - December 31, 2014). The second cohort included patients in the PSH model without EMR integration (January 1, 2015 – August 1, 2016). The third cohort included patients in the PSH model with EMR integration (August 1, 2016 - April 1, 2018). The clinical outcome criteria measured were average hospital length of stay (LOS), 30-day readmission rates, and discharge disposition. Financial data was collected for each cohort and primary measurements included average total cost, diagnostic cost, anesthesia cost, laboratory cost, room and board cost, and physical therapy cost. Results. Overall, 3,384 primary total joint arthroplasty cases were included. Implementation of a PSH without EMR significantly reduced LOS (1.79 vs 3.59, p<0.05), readmission rates (1.9% vs 4.3%, p<0.05), and decreased the rate of skilled nursing facility (SNF) disposition (15.2% vs 31.1%, p<0.05) and increased discharge to home care (84.8% vs 68.9%, p<0.05). EMR integration did not significantly reduce LOS or readmission rates but did further decreased the rate of SNF disposition (10.2% vs 15.2%, p<0.05), while increasing the rate of home care disposition (89.8% vs 84.8%, p<0.05). Per case, implementation of the PSH model without EMR integration decreased diagnostic cost (−$9.37, p<0.05), anesthesia cost (−$71.34, p<0.05), room and board cost (−$285.18, p<0.05) and total overall cost (−$1432.38, p<0.005). Integrating pathways into an EMR led to further cost-reduction in laboratory cost (−$47.04, p<0.05), physical therapy cost (−$57.79, p<0.05), and total overall cost (−$2,837.28, p<0.05). EMR integration did not lead to significant increases in other cost variables. Conclusions. The implementation of a PSH model for total joint arthroplasty, especially with electronic medical record integration, reduces cost, average LOS, 30-day readmissions, and increases discharge to home care

Introduction. Pulmonary embolism (PE) complicates up to 1% of total joint arthroplasties (TJA). Many PE treatment guidelines call for immediate initiation of therapeutic anticoagulation. Options include Xa inhibitors, Enoxaparin, and Warfarin. Deciding between these is a balance of the efficacy and the risks. Little data exists regarding the risks of each of these treatment options for treating PE in arthroplasty patients. Methods. We examined the records of 29,270 patients who underwent a primary total joint arthroplasty (TJA), defined as a unilateral total knee arthroplasty (TKA) (18,987) or total hip arthroplasty (THA) (10,283), between 2/2016 and 12/2018 at our institution and identified 338 (242 TKA, 96 THA) patients who developed an in-hospital PE treated with therapeutic anticoagulation. The patients were treated with therapeutic doses of Xa inhibitors, enoxaparin or warfarin. The type and frequency of complications were determined and classified as major or minor. Major complication included: bleeding requiring surgery, GI bleed requiring treatment, >2 unit transfusion and mortality. Minor complications included wound drainage, bleeding not requiring surgery, and thrombocytopenia. Results. Overall complication rates were high for all treatments. Xa inhibitors had the lowest complication rate at 14% compared to 20% for enoxaparin and 20.7% for warfarin though the difference did not quite reach statistical significance (p=.054). Both major and minor complication were lower with Xa inhibitors, but again the difference was not statistically significant (p=0.67). There was no significant difference in complications between TKA groups (p=0.73) or THA groups (p=0.83). Gender and body mass index were not predictive of major or minor complications. Discussion. Our results demonstrate high complication rates associated with modern therapeutic anticoagulation protocols for perioperative PE following TJA. Patients who receive therapeutic anticoagulation postoperatively are at high risk for complication. Xa inhibitors may decrease these risks, but larger studies are required

Perioperative antibiotic prophylaxis remains one of the most important strategies for prevention of periprosthetic joint infection (PJI) with current guideline recommending a first or second generation cephalosporin. Penicillin (PCN) allergy is often reported by patients, which often results in avoidance of administration of cephalosporins due to fear of cross-reactivity. Alternative medications, such as vancomyin, are often used despite reduced antimicrobial coverage. The purpose of this study was to determine if PCN allergic patients who received vancomycin alone prior to elective primary total joint arthroplasty were at increased risk of developing a subsequent PJI. A retrospective review of 7,602 primary total joint arthroplasties (TJAs) performed between 2005 and 2013 in two institutions were identified using a prospective institutional database. Patient reported PCN or cephalosporin allergy was electronically queried from the anesthesia note. Patients who recieved multiple prophylactic antibiotics, or had unavailable perioperative antibiotic information, or those who received medication other than cefazolin and vancomycin were excluded. PJI was determined using a cross-match with an institutional PJI database constructed from International Classification of Diseases (ICD)-9 codes. Logistic regression analysis was then performed to evaluate the risk of subsequent PJI. The rate of PJI was 1.4% (32/2296) in patients with a reported PCN allergy that received vancomycin alone versus 1.1% (59/5306) in non-PCN allergic patients that received cefazolin alone. The multivariate analysis, with the given sample size, did not detect a statistically significant increased risk of PJI when vancomycin was administered alone (adjusted odds ratio: 1.23, 95% CI 0.6–3.1, p=0.35). While there was no significant differences in the organism profile between PJIs in both groups, the rate of PJI caused by resistant organisms was higher in patients who received vancomycin alone (11.9%, 7/59) compared to those who received cefazolin (3.1%, 1/32). While administration of perioperative prophylactic vancomycin alone during elective primary arthroplasty does not seem to result in a higher rate of subsequent PJI, patients who received vancomycin alone and developed a PJI were more likely to develop an infection with an antibiotic resistant organism. Future studies are needed to determine the most appropriate prophylactic antibiotic for patients who undergo elective arthroplasty and report PCN allergy

Patients who are actively smoking at the time of primary total joint arthroplasty (TJA) are at considerably increased risk of perioperative complications. Therefore, strategies to assist patients with smoking cessation before surgery have become routine practice. A secondary benefit is the theoretical catalyst for long-term smoking cessation. However, questions remain as to whether patients actually cease smoking prior to the procedure, and if so, how long this lasts postoperatively. Our high-volume, academic institution documents self-reported smoking status at each clinic visit (at 6-month intervals), as well as at the time of surgery through a total joint registry. As such, all patients who underwent TJA from 2007 to 2018 were identified and grouped as: non-smokers, smokers (regularly smoking cigarettes within 1 year from surgery), and former smokers (those who quit smoking within a year before surgery). Thereafter, smoking status in the postoperative period was assessed, with special attention to the former smokers in order to see who remained smoke-free. From the 28,758 primary TJAs identified, 91.3% (26,244) were non-smokers, 7.3% (2,109) were smokers, and 1.4% (405) had quit smoking before surgery. Among patients who quit smoking before surgery, only 38% were still abstinent at 9 years from surgery. Conversely, 24% of smokers at the time of surgery eventually quit and 3.1% of non-smokers started smoking over the same time period. Despite a concerted effort to help patients stop smoking before TJA, an important proportion (7.3%) are unsuccessful. Among those patients who do manage to stop smoking, only a minority (38%) remain smoke-free after surgery. Compared to current smokers, patients who managed to quit before surgery are more likely to remain smoke-free after surgery. These findings highlight that smoking remains a tremendous challenge in contemporary TJA practices. Additional strategies targeting smoking cessation before after surgery are needed

The purpose of this study was to evaluate the impact of dalteparin use on transfusion rates and blood loss in patients undergoing primary total joint arthroplasty at our center. We prospectively studied the transfusion patterns of 1642 patients who underwent primary total hip or knee arthroplasty between January 2004 and December 2005 by five arthroplasty surgeons. The influence of daltaperin use, release of tourniquet in total knee arthroplasty, and the turnover of house staff were analyzed using SPSS V14.0 statistical software. We identified seven hundred and three total hip and nine hundred and thirty-nine knee arthroplasty patients. The mean haemoglobin drop was statistically significant between 2004 and 2005 (p< 0.001). This was seen in both hip (p=0.014) and knee (p< 0.001) patients. Subgroup analysis of total knee arthroplasty revealed a significant difference in haemoglobin drop between surgeons who released the tourniquet prior to closure compared to release at the end of the case (p=0.005). In addition, there were significant monthly differences that corresponded with the turnover of house staff (p=0.039). Overall, no statistically significant increase in allogeneic transfusion rates was observed between years, months, and individual surgeons. The use of dalteparin was found to be associated with a significantly increased haemoglobin drop in primary total joint replacement when compared to warfarin. However, the use of dalteparin was not associated with an increase in allogeneic transfusions at our center. The results also suggest that there may be an advantage to releasing the tourniquet and achieving hemostasis prior to closure in knee arthroplasty. Finally, the results emphasise the importance of educating new house staff on methods to reduce intra-operative blood loss and transfusion rates