Ten Year Experience With Same Day Discharge Outpatient Total Hip Arthroplasty: Patient Demographics Changed, but Safe Outcomes Were Maintained.

BACKGROUND: This study aimed to characterize changes in patient demographics and outcomes for same-day discharge total hip arthroplasty (THA) over a 10-year period at a single orthopaedic specialty hospital. METHODS: A consecutive series of 1,654 patients between 2013 and 2022 who underwent unilateral THA and were discharged on the same calendar day were retrospectively reviewed. Patient demographics, including age, sex, body mass index (BMI), age-adjusted Charlson Comorbidity Index, and American Society of Anesthesiologists (ASA), were collected. Readmissions, complications, and unplanned visits were recorded for 90 days postoperatively. In order to compare the demographics of patients over time, patients were divided into 3 groups: Time Group A (2013 to 2016), Time Group B (2017 to 2019), and Time Group C (2020 to 2022). RESULTS: The mean age, BMI, ASA score, and CCI increased significantly across each time group. Age increased from 57 years (range, 23 to 77) to 60 years (range, 20 to 87). The BMI increased from 28.1 (range, 18 to 41) to 29.4 (range, 18 to 47). The percentage of patients aged > 70 years almost doubled over time, as did the percentage of patients who had a BMI > 35. Overall complications increased from 3.44 to 6.82%, reflective of the changing health status of patients. Readmissions increased from 0.57 to 1.70% over time. Despite this, there were no readmissions for any patient within the first 24 hours of surgery. CONCLUSIONS: Our study has 3 important findings. We identified a worsening patient demographic over time with an increasing percentage of patients of advanced age and higher BMI, ASA, and age-adjusted Charlson Comorbidity Index. Also, there was also an increase in readmissions, complications, and unplanned visits. In addition, despite this worsening patient demographic, there were no readmissions within 24 hours and a low rate of readmissions or unplanned visits within the first 48 hours across all time periods, suggesting that same-day discharge-THA continues to be safe in properly selected patients.

Methylene Blue Infiltration As a Method for Distinguishing Superficial and Deep Infections.

BACKGROUND: There are no established objective methods to reliably differentiate between superficial and deep infection in the setting of total hip arthroplasty. We employed a technique of distinguishing superficial and deep infections by infiltrating methylene blue to a prosthetic hip during infection workup to determine its effectiveness and to characterize its utility in defining the joint cavity where deep debridement is required. METHODS: An analysis was conducted on 35 patients who preoperatively received an injection of methylene blue under radiological guidance to their total hip arthroplasty. Where established periprosthetic joint infection (PJI) criteria were not met, without signs of methylene blue beyond the deep fascia, the infection was considered superficial, and debridement remained superficial to the deep fascia. Where diagnosis of PJI was confirmed preoperatively or the presence of methylene blue in the wound cavity confirmed deep contamination, the prosthesis was addressed with methylene blue staining defining the joint cavity as a guide for debridement. RESULTS: There were 11 patients who had no methylene blue extrusion into the superficial compartment and did not meet PJI criteria. Eight patients failed to meet PJI criteria preoperatively, but had extrusion of methylene blue, confirming a deep infection intraoperatively. There were 16 patients who met PJI criteria preoperatively with methylene blue acting as a visual guide to the joint space. CONCLUSION: Infiltrating methylene blue in a prosthetic hip is useful in differentiating between superficial or deep infections where PJI workup is indeterminate. Where deep infection is present, its utility in defining the joint cavity may be advantageous.

Vertical or Horizontal (Bikini) Incision for Direct Anterior Total Hip Arthroplasty: Outcomes of Early (<90 day) Revision.

BACKGROUND: The horizontal 'bikini' incision for direct anterior approach (DAA) total hip arthroplasty has gained popularity due to its early wound healing characteristics; however, the nonextensile nature of this approach may pose problems in treating early complications. This study sought to characterize the outcomes of early revision (<90 days) in patients who underwent anterior hip arthroplasty utilizing either a traditional longitudinal incision or a horizontal (bikini) incision. METHODS: This retrospective study identified patients who underwent DAA primary total hip arthroplasty with a subsequent DAA revision within 90 days. Patients were divided into two cohorts based on the orientation of their incision: either 'longitudinal incision' (in accordance with the Smith Peterson interval) or 'horizontal bikini incision' (in accordance with the hip flexion crease). RESULTS: There were 74 patients who underwent DAA revision arthroplasty within 90 days of primary arthroplasty; 65 had a longitudinal incision, and 9 had a horizontal (bikini) incision. In the longitudinal incision group, 2 patients (3.1%) required plastic surgery closure, and 11 patients (16.9%) required additional operations. Of the 9 bikini incision patients, 6 patients required the assistance of plastic surgery closure, and 7 patients required multiple orthopaedic operations. CONCLUSIONS: Our study suggests that a horizontal bikini incision is less forgiving in the early postoperative period if a more extensile exposure is needed for revision surgery, as measured by the need for plastic surgery and additional returns to the operating room. In our cohort, the longitudinal incision allowed for the management of early surgical complications with less morbidity.

Antibiotic-loaded cement in total joint arthroplasty: a comprehensive review.

This review evaluates the decision-making framework for using antibiotic-loaded cement (ALC) in the management of prosthetic joint infection (PJI). Drawing on available literature, we offer orthopaedic surgeons a guided discussion on several critical considerations. First, we explore the impact of antibiotic-loading on the mechanical properties of polymethylmethacrylate (PMMA) cement, assessing both strength and durability. We then explore the optimal antibiotic dosage to load into cement, aiming to achieve effective local concentrations for infection control without compromising mechanical stability. Furthermore, we explore how cement and antibiotic properties affect the overall antibiotic elution characteristics of ALC. Finally, we discuss risks of systemic toxicity, particularly acute kidney injury, when using ALC. The principal goal in this review is to provide a balanced approach based on best available evidence that optimises antibiotic elution from ALC whilst minimising potential harms associated with its use.

Defining Reference Values for the Normal Adult Lisfranc Joint Using Weightbearing Computed Tomography.

The uninjured contralateral feet of consecutive patients undergoing cone-beam weightbearing computed tomography for acute Lisfranc injury between July 2017 and October 2019 were retrospectively analyzed. Of these, any cases with history or radiological evidence of trauma to the Lisfranc interval were excluded. The area of the non-weightbearing (NWBA) and weightbearing (WBA) Lisfranc joint was calculated (in mm2) using a novel technique. Area difference (AD) was calculated as WBA-NWBA. Area ratio (AR) was calculated as WBA/NWBA. A subset of cases was double-measured by 2 technologists to evaluate inter- and intraobserver variability. A total of 91 patients aged 15 to 74 years were included in the study. The measurement technique was reproducible with excellent intraobserver correlation (intraclass correlation coefficient [ICC]: 0.998, 95% confidence interval [CI]: 0.996-0.999) and high interobserver correlation (ICC: 0.964, CI: 0.939-0.979). The median NWBA was 83 (range 52-171) and median WBA was 86 (range 52-171). Median AD was 1 mm2 (range -3 to 10) and median AR was 1.01 (range 0.96-1.11). No significant difference was identified in AD or AR when adjusted for age, gender, patient-weight or weight put through the foot. Both AD and AR distributions were highly skewed toward 0 and 1, respectively. Based on 95% CI, normal reference range for AD is -1 to 7 mm2 and for AR is 0.98 to 1.09. Absolute area of the Lisfranc joint is highly variable between individuals. The Lisfranc joint is rigid with little to no physiologic widening in most subjects. The normal upper limit of widening of the Lisfranc area on weightbearing was 9%. Differences in age, sex, patient-weight or weight put through the foot were not significantly associated with the extent of joint widening.

OBTAIN A: Outcome Benefits of Tranexamic Acid in Hip Arthroplasty. A Randomized Double-Blinded Controlled Trial.

BACKGROUND: We examined whether the blood conserving effect of tranexamic acid (TXA) in total hip arthroplasty using the direct anterior approach, translates to an effect on functional outcomes in the perioperative period. METHODS: We conducted a single-center, randomized, double-blinded, placebo-controlled trial. One hundred one patients were randomized to receive either TXA or an equivalent volume of normal saline. The primary outcome measure was thigh swelling. Secondary outcome measures included, visual analogue pain score, timed up and go test, a 10 meter walk test, and length of stay. Blood loss and the incidence of blood transfusions were also recorded. RESULTS: There were no statistically significant differences between the primary outcome of thigh swelling or the secondary outcome measures of postoperative pain nor mobility. There was a significant reduction in length of stay for those that received TXA 3.58 days (0.84) compared with the control group 4.27 days (0.98) (P < .001). There was significantly less intraoperative blood loss observed in the TXA group (0.460L SD 0.228) compared with the control group (0.687L SD 0.283L) (P < .001). The estimated blood loss was also significantly less in the TXA group (1.084L SD 0.440) compared with the control group (1.394 L SD 0.426). CONCLUSION: TXA is an effective agent in reducing blood loss in total hip arthroplasty using the anterior approach. The blood conserving effect of TXA was not associated with improved postoperative recovery across the measures of pain and mobility. Administration of TXA may have a positive effect on reducing the duration of inpatient stays.

Internet based patient education improves informed consent for elective orthopaedic surgery: a randomized controlled trial.

BACKGROUND: Obtaining informed consent is an essential step in the surgical pathway. Providing adequate patient education to enable informed decision making is a continued challenge of contemporary surgical practice. This study investigates whether the use of a patient information website, to augment patient education and informed consent for elective orthopaedic procedures is an effective measure. METHODS: A randomised controlled trial was conducted comparing the quality of informed consent provided by a standard discussion with the treating surgeon compared to augmentation of this discussion with an online education resource (www.orthoanswer.org). Participants were recruited from orthopaedic outpatient clinics. Patients undergoing five common orthopaedic procedures were eligible to participate in the trial. The primary outcome measure was knowledge about their operation. Satisfaction with their informed consent and anxiety relating to their operation were the secondary outcome measures. RESULTS: There was a statistically significant increase in patient knowledge for the intervention arm as compared to the control arm (p < 0.01). Patients in the intervention arm, had an average score of 69.25% (SD 14.91) correct answers as compared to 47.38% (SD 17.77) in the control arm. Satisfaction was also improved in the intervention arm (p = 0.043). There was no statistically significant difference between the control and intervention arm relating to their anxiety scores (p = 0.195). CONCLUSIONS: The use of a patient education website as an augment to informed consent improves patient knowledge about their planned operation as well as satisfaction with the consent process whilst not increasing their anxiety levels. We recommend that all patients be directed to web based education tools to augment their consent. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12614001058662 .

Management of Isolated Greater Trochanter Fractures Associated With Total Hip Arthroplasty.

Periprosthetic hip fractures are recognized complications associated with total hip arthroplasty. Over the past decade, there has been a 2.5-fold increase in the incidence of periprosthetic fractures which is expected to grow exponentially in the future. Most of these fractures require surgical fixation or revision arthroplasty. Fractures of the greater trochanter represent a subset of periprosthetic fractures for which there is currently no consensus in the literature regarding the optimal management. The purpose of this review was to outline the management strategies available to address these fractures, with formulation of recommendations for fractures sustained intraoperatively, postoperatively, and in the setting of primary and revision total hip arthroplasty.

The ability of artificial intelligence tools to formulate orthopaedic clinical decisions in comparison to human clinicians: An analysis of ChatGPT 3.5, ChatGPT 4, and Bard.

Background: Recent advancements in artificial intelligence (AI) have sparked interest in its integration into clinical medicine and education. This study evaluates the performance of three AI tools compared to human clinicians in addressing complex orthopaedic decisions in real-world clinical cases. Questions/purposes: To evaluate the ability of commonly used AI tools to formulate orthopaedic clinical decisions in comparison to human clinicians. Patients and methods: The study used OrthoBullets Cases, a publicly available clinical cases collaboration platform where surgeons from around the world choose treatment options based on peer-reviewed standardised treatment polls. The clinical cases cover various orthopaedic categories. Three AI tools, (ChatGPT 3.5, ChatGPT 4, and Bard), were evaluated. Uniform prompts were used to input case information including questions relating to the case, and the AI tools' responses were analysed for alignment with the most popular response, within 10%, and within 20% of the most popular human responses. Results: In total, 8 clinical categories comprising of 97 questions were analysed. ChatGPT 4 demonstrated the highest proportion of most popular responses (proportion of most popular response: ChatGPT 4 68.0%, ChatGPT 3.5 40.2%, Bard 45.4%, P value < 0.001), outperforming other AI tools. AI tools performed poorer in questions that were considered controversial (where disagreement occurred in human responses). Inter-tool agreement, as evaluated using Cohen's kappa coefficient, ranged from 0.201 (ChatGPT 4 vs. Bard) to 0.634 (ChatGPT 3.5 vs. Bard). However, AI tool responses varied widely, reflecting a need for consistency in real-world clinical applications. Conclusions: While AI tools demonstrated potential use in educational contexts, their integration into clinical decision-making requires caution due to inconsistent responses and deviations from peer consensus. Future research should focus on specialised clinical AI tool development to maximise utility in clinical decision-making. Level of evidence: IV.

Comparable Results of Single and Two-Stage Exchange for Select Periprosthetic Hip and Knee Infection.

INTRODUCTION: Although two-stage exchange has been the standard of care for periprosthetic joint infection (PJI) in the United States, single-stage exchange is emerging as an option in select patients. The purpose of this study was to compare outcomes of patients undergoing single-stage and two-stage exchange using strict surgical indications. METHODS: We reviewed a consecutive series of 196 patients with diagnosed PJI undergoing revision total knee and hip arthroplasty from 2017 to 2021. Patients were excluded if they had PJI history, plastic surgery coverage, or extensive bone loss requiring endoprosthesis. We compared the number of patients PJI-free at 1-year follow-up using MusculoSkeletal Infection Society criteria and patients requiring re-revision between the single-stage and two-stage groups. RESULTS: In total, 126 patients met inclusion criteria. Of 61 knee patients (48.4%), 22 underwent single-stage (36%) and 39 underwent two-stage (63.9%). Of 65 hip patients (51.6%), 38 underwent single-stage (58.5%) and 27 underwent two-stage (41.5%). At a mean follow-up of 1.95 ± 0.88 years, a higher rate of knee patients were classified as having treatment success in the single-stage group (77.3% versus 69.2%, P = 0.501), however with comparable septic failure rates (18.1% single-stage versus 17.9% two-stage; P = 0.982). At a mean follow-up of 1.81 ± 0.9 years, a higher rate of hip patients were classified as having treatment success in the single-stage group (94.7% versus 81.5%, P = 0.089), and more patients had septic failures in the two-stage group (18.5% versus 5.3%; P = 0.089). No differences were observed in the microorganism profile. More total complications (P = 0.021) and mortalities were found in the single-stage knee cohort than in the two-stage cohort (22.7% versus 2.6%; P = 0.011). CONCLUSION: Single-stage arthroplasty is a viable alternative to standard two-stage exchange in patients with PJI without a history of infection and with no bone or soft-tissue compromise. Additional studies with longer term follow-up are needed to evaluate its efficacy.

Serum and Synovial Markers in the Diagnosis of Periprosthetic Joint Infection of the Hip, Knee, and Shoulder: An Algorithmic Approach.

➤ No single test has demonstrated absolute accuracy for the diagnosis of periprosthetic joint infection (PJI).➤ Physicians rely on a combination of serological tests, synovial markers, and clinical findings plus clinical judgment to help to guide preoperative decision-making.➤ Several organizations have proposed criteria for the diagnosis of hip or knee PJI on which we now rely.➤ Given that shoulder arthroplasty has only recently become popular, it is possible that a shoulder-specific definition of PJI will be introduced in the coming years.➤ Although a number of serum and synovial markers have demonstrated high accuracy for the diagnosis of PJI of the hip and knee, further research is needed in order to identify markers that may be more suitable for the diagnosis of shoulder PJI and for the potential development and identification of specific serological tests as screening tools for PJI.

Assessment of the quality of web-based information on bunions.

BACKGROUND: The Internet provides a large source of health-related information for patients. However, information on the Internet is mostly unregulated, ranging from factually correct to misleading or contradictory information. The objective of this study was to determine the quality of information available on World Wide Web on the topic of bunions. METHODS: Websites were identified using 3 search engines (Google, Yahoo, and MSN) and the search term bunions. The first 30 websites in each search were analyzed. Websites were assessed using the validated DISCERN rating instrument to determine the quality of health content and treatment information. The DISCERN tool possesses moderate to very good strength of interobserver agreement, ranging from .41 to .82. RESULTS: A total of 90 websites were assessed and studied. Forty-eight sites were duplicated, leaving 42 unique sites. Of these, 60% (25/42) provided patient-related information, 21% (9/42) were advertisements, 7% (3/42) promoted medical centers, 5% (2/42) were dead links, 5% (2/42) were news articles, and 2% (1/42) was doctor's information. In determining the quality of unique sites, of a maximum score of 5, the average overall DISCERN score was 2.9 (range, 1.8 to 4.6). Only 24% (10/42) of websites were classified as "good" or "excellent." Although most websites contained information on symptoms, causes, risk factors, investigations, and treatment options on bunions, 60% (25/42) did not provide adequate information on the benefits for each treatment, 45% (19/42) did not contain any risks of treatment, and 76% (32/42) did not describe how treatment choices affect overall quality of life. The sources of information were clear in 33% (14/42), and the date when this information was reviewed was given in only 50% (21/42). Only 29% (12/42) of websites had been updated within the past 2 years. CONCLUSIONS: Overall, the quality of patient information on bunions varies widely. We believe clinicians should guide patients in identifying the best possible and genuine information on the World Wide Web. CLINICAL RELEVANCE: Patients are commonly using the internet as an information resource, in spite of the highly variable quality of this information. They should be encouraged to exercise caution and to utilize only well-known sites.

Managing the Patient with Peripheral Vascular Disease before Total Knee Arthroplasty Surgery.

Peripheral vascular disease (PVD), defined as decreased arterial perfusion to the lower extremities due to atherosclerotic obstruction, is known to occur in patients undergoing total knee arthroplasty with described rates of between 2% and 4.5% PVD is of significance for patients undergoing TKA as it can increase wound healing and infection complications after TKA and is an independent risk factor for arterial complications following TKA. Our goal is to provide a comprehensive review of the pathophysiology of PVD as it relates to TKA, associated outcomes of patients undergoing TKA in the setting of PVD, diagnostic pearls, and current management strategies recommended in the published literature.

The Use of Iodophor-Impregnated Drapes in Patients With Iodine-Related Allergies: A Case Series and Review of the Literature.

Background: The use of iodophor-impregnated adhesive drapes have become almost universally incorporated into standard practice of arthroplasty draping technique. Iodine-related allergies in patients planned for joint replacement present a challenge in terms of the best course of action to minimize complications and optimize outcomes. Methods: This is a retrospective case series of patients that received an iodophor-impregnated drape as part of draping for a total hip or knee arthroplasty at a single orthopaedic-specific hospital with documented iodine-related allergies. From 2015 to 2023, 9816 total hip arthroplasty and total knee arthroplasty cases were reviewed, and 135 were documented to have an iodine-related allergy for a prevalence of 1.38%. Intraoperative and postoperative records were reviewed to screen for an allergic reaction or wound healing issues that may have been related to an adverse reaction to the use of the iodophor-impregnated drape. Results: Of the 135 patients, 43 had iodine listed as an allergy, 85 had shellfish, 20 had iodinated contrast media, and 3 had povidone iodine. Sixteen patients had a cluster of iodine-related allergies. There were no intraoperative reports of an allergic reaction to this drape. There were four superficial wound problems, none of which were documented to relate to an allergic dermatitis reaction, and none required further surgery. Conclusions: Patients reporting iodine-related allergies were present in 1.38% of patients undergoing hip or knee arthroplasty in our series. We encountered no allergic reactions or adverse outcomes that could be attributed to the use of iodiphor impregnated drapes in these patients.

Utility assessment of virtual reality technology in orthopaedic surgical training.

BACKGROUND: Virtual reality (VR) has proved to be a useful technology beyond the field of surgery in areas that are highly dependent on consolidating motor tasks. Despite being reliant on these skills, the uptake of VR in orthopaedics has been extremely limited. Therefore, this study's purpose was to help assess the utility of applying this technology in teaching different experience levels of orthopaedic training. Secondary objectives were to assess enjoyability and feasibility to complete modules prior to surgery. METHODS: The study explored which experience level of orthopaedic trainee benefits the most from the proposed haptic VR package. Participants completed a total hip arthroplasty module using the Fundamental Surgery package. Qualitative data was collected in the form of a post completion survey of 24 participants. Quantitative data was collected in the form of module completion time and percentage of skills completed. RESULTS: 37.5% of participants rated non-training orthopaedic registrars as the experience level that would benefit the most from using VR. 88% of participants would recommend this module to a colleague and found the module very enjoyable (4.2 out of 5). 50% of participants took between 25 and 31.5 min to finish and completed between 80% and 95% of tasks in the module. CONCLUSIONS: The study demonstrated that non-training orthopaedic registrars were most likely to benefit using this particular VR package. Most users found the experience to be enjoyable and would recommend it to a colleague. It was also deemed feasible to complete the module prior to performing an operation.

Initial Experience with the NAVIO Robotic-Assisted Total Knee Replacement-Coronal Alignment Accuracy and the Learning Curve.

One of the primary aim of total knee arthroplasty (TKA) is restoration of the mechanical axis of the lower limb. Maintenance of the mechanical axis within 3 degrees of neutral has been shown to result in improved clinical results and implant longevity. The aim of this study was to investigate the efficacy of this robotic-assisted system in coronal plane component positioning in TKA. We also describe the learning curve associated with adoption of this technology. A total of 72 total knee replacements were completed between November 2017 and September 2018 by a single surgeon using the robotic-assisted surgery (RAS) system. Cases were recorded from the time the study surgeon first adopted this technology and represent the "learning curve." Pre- and postoperative coronal weight-bearing alignments were measured and intraoperative robotic-assisted registration data and duration of use were collected. Of the 72 TKAs in this series, 93.3% were corrected to the desired alignment of within 3 degrees of neutral. The knees that were not corrected to neutral had a mean preoperative alignment of 11.57 degrees of deformity as compared with 4.29 degrees for those that were corrected to neutral. A learning curve effect during adoption of this new technology was not found when analyzing RAS usage time. The RAS system produced accurate coronal alignment in TKA in more than 93% of cases with no learning curve effect. Our study suggests that this system is easily adopted, safe, and accurate.

Early mobilization vs delayed mobilisation following the use of a volar locking plate with non-vascularized bone graft in scaphoid non-union. A multicentred randomised controlled-trial.

PURPOSE: This randomized clinical trial investigated the potential for early mobilization of the wrist following open reduction and internal fixation (ORIF) with a scaphoid specific volar locking plate and non-vascularized bone graft for scaphoid non-union. METHODS: 16 patients with scaphoid non-union underwent internal fixation with a scaphoid-specific volar locking plate and iliac crest bone graft and were randomized to one of two treatment arms (A) The control were immobilized in a below elbow cast for 6 weeks (n = 9) and (B) The experimental arm were mobilized early with a removable wrist splint (n = 7). Outcomes were measured preoperatively, and at 3 months post operatively. These included the primary outcome of union, and secondary outcomes of grip strength and patient reported outcomes of disabilities of arm shoulder and hand (DASH) and patient reported wrist evaluation (PRWE). Discrete variables were analyzed using the chi squared test while continuous variables used the students t-test. RESULTS: The experimental (early mobilization) group developed metalware complications resulting in the early termination of the study. No significant difference in the demographic characteristics of age, gender, time to surgery, smoking status and handedness was found between groups. A significant difference was found in BMI, with significantly higher proportion of obese patients (p = 0.05) in the experimental group. There was no significant difference in the primary outcome measure of the rate of union between groups. The secondary outcomes of grip strength, Dash and PRWE also showed no significant difference between the immobilized and mobilized groups. CONCLUSION: We recommend immobilization following scaphoid non-union ORIF using a volar locking plate due to high complication rates in our cohort with early mobilization.Type of study/level of evidence: Therapeutic 2.Trial registration.Australian New Zealand Clinical Trials Registry (ACTRN12614001050640). Date of registration, 02/10/2014.

Scaphoid specific volar locking plate and non-vascularised iliac crest bone graft in scaphoid non-union. A comparative cohort study.

Scaphoid non-union develops in 10% of scaphoid fractures. There is sparse literature on fixation methods other than screws. We compared union rates following fixation of scaphoid non-union using screw fixation and a novel method of plate fixation. Retrospective study. Union rates were assessed at 3 months post-operatively by a musculoskeletal radiologist. 15 patients underwent screw fixation and 15 underwent plate fixation. 86% union rate with screw fixation and 72% plate fixation united. There was no significant difference. Screw fixation and plate fixation in our institution both provide union rates that are consistent with the literature.

OBTAIN E: outcome benefits of tranexamic acid in hip arthroplasty with enoxaparin: a randomised double-blinded controlled trial.

BACKGROUND: We examined the blood conserving effect of tranexamic acid in total hip arthroplasty using the direct anterior approach with enoxaparin as deep vein thrombosis (DVT) chemoprophylaxis, and whether this translates to an effect on functional outcomes in the perioperative period. We also compare the effect of aspirin and enoxaparin as DVT chemoprophylactic agents. METHODS: We conducted a single-centre randomised, double-blinded, placebo-controlled trial. 105 patients were randomised to receive either tranexamic acid or an equivalent volume of normal saline with enoxaparin used as DVT chemoprophylaxis. The primary outcome measure was thigh swelling. Blood loss and the incidence of blood transfusions was also recorded. Secondary outcome measures including postoperative functional scores and mobility, pain scores and length of stay. We also compared and pooled the results of a previous study with the same study intervention methodology which used aspirin as DVT chemoprophylaxis instead of enoxaparin. RESULTS: There were no statistically significant differences between the primary outcome of thigh swelling. There was significantly less intraoperative blood loss observed in the tranexamic acid (TXA) group (0.510 L, SD 0.210) compared with the control group (0.698, SD 0.301) ( p < 0.001). The estimated blood loss was also significantly less in the TXA group (1.130 L, SD 0.311) compared with the control group (1.48 L, SD 0.510) ( p < 0.001). Pooled data of both consecutive trials showed there was a statistically significant reduction in length of stay for those that received TXA (3.72 days, SD 0.83 versus 4.24 days, SD 0.97, p < 0.001). There was also a statistically significant increased risk of a transfusion in the control group as compared those that received TXA (OR 5.5, 1.188 to 25.449, p = 0.029). There was no difference in blood loss between DVT chemoprophylactic agents. INTERPRETATION: TXA is an effective agent in reducing blood loss in THR using the anterior approach and was not affected by choice of DVT chemoprophylaxis. Patients who received TXA had fewer transfusions and a reduction in their length of stay. The blood conserving effect of TXA was not associated with improved postoperative recovery across the measures of pain and mobility. CLINICAL TRIALS REGISTRATION: ANZCTR number: ACTRN12616000606482.