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Immobilization after Fixation of Distal Radial Fractures

short arm castOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD, in response to a recent study in JBJS.

Postoperative immobilization after internal fixation of fractures is common practice. However, immobilization after locked volar plate fixation of distal radial fractures may actually thwart our patients’ rehabilitation—at least in the short term. So suggest the findings from Watson et al. in the July 5, 2018 issue of JBJS.

The authors randomized 133 patients who underwent locked volar plate fixation of distal radial fractures to 1, 3, or 6 weeks of postoperative immobilization. All patients were placed into volar splints postoperatively. After 1 week, splints were removed entirely or converted to short-arm circumferential casts based on the patient’s allocation. All patients started physical therapy within 3 days of definitive splint or cast removal.

Outcomes were evaluated at 6, 12, and 26 weeks and included patient-reported measures (PRWE, VAS pain scores, and DASH), active wrist range of motion, and postoperative complications. Six weeks following surgery, the results favored 1 or 3 weeks of immobilization over 6 weeks of casting in terms of improved patient-reported outcomes and objective wrist range of motion. However, those between-group differences disappeared at 12 and 26 weeks of follow-up. No significant differences were found in complication rates between the 3 groups.

For me, the primary message of this article is that early mobilization after distal radial fracture fixation offers improved short-term outcomes with little or no risk of adverse effects. For most patients, a major goal of fracture treatment is to restore normal function as quickly as possible. With early mobilization, patients reported less pain and less disability, and they demonstrated greater range of motion at 6 weeks.

However, the quick restoration of function must be done safely and without complications. In this cohort, 6 patients lost fracture reduction—5 in the 1-week immobilization group and 1 in the 6-week group. While that difference was not statistically significant, the study was not sufficiently powered to detect that difference. A quick power analysis, assuming an anticipated 11% loss-of-reduction rate as seen in the 1-week group and a 2% rate as seen in the 6-week group, estimates that 234 patients would be needed to confidently avoid a type II error when analyzing loss of reduction.

Translating findings like these into practice constitutes the art of medicine. It is probably safe, and perhaps even beneficial, to allow early mobilization of distal radial fractures treated with volar locking plates. However, there is probably a subset of patients who are at risk for losing reduction, and therefore it may be prudent to have a low threshold for keeping certain patients casted for a longer duration. The orthopaedist who extends cast immobilization beyond 3 weeks can take comfort in the findings that reported outcomes and range of motion in the 6-week-immobilization group quickly caught up with the results of the early-mobilization cohorts by 12 weeks after surgery.

Matthew Herring, MD is a fellow in orthopaedic trauma at the University of California, San Francisco and a member of the JBJS Social Media Advisory Board.

Guest Post—Peer Reviewers: Who Are They and Do They Agree?

Medical-Research Image for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Christopher Dy, MD, MPH, in response to a recent study in PNAS.

I am a young surgeon, but I have been submitting papers and grants for peer review for 11 years, since I was a third-year med student. I have tasted the bitterness of rejection more times than I would like to admit, several times at the hands of JBJS. But I will say, without a doubt, that the peer-review process has made my work better.

Acknowledging that our work is far from perfect at the point of submission, most of us have turned the question around: How good and reliable is the peer-review process? Several related questions arise quickly: Who are the “peers” doing the reviewing? We put weeks and months into writing a paper or submitting a grant, which then vanishes into the ether of a review process. How do we know that we are getting a “fair shake” from reviewers, who, being human, carry their own biases and have their own limitations and knowledge gaps—in addition to their expertise? And do the reviewers even agree with each other?

Many authors can answer “no” to that last question, as they have likely encountered harmony from Reviewers 1 & 3 but scathing dissent from Reviewer 2. Agreement among reviews was the question examined by Pier et al. in their recent PNAS study. Replicating what many of us consider the “highest stakes” process in scientific research, NIH peer review, the authors convened four mock study sections, each with 8 to12 expert reviewers. These groups conducted reviews for 25 R01 grant proposals in oncology that had already received National Cancer Institute funding. The R01 is the most coveted of all NIH grants; only a handful of orthopaedic surgeons have active R01 grants.

Pier et al. then evaluated the critiques provided by the reviewers assigned to each proposal, finding no agreement among reviewer assessments of the overall rating, strengths, and weaknesses of each application.  The authors also analyzed how well these mock reviews paired to the original NIH reviews. The mock reviewers (all of whom are R01-funded oncology researchers) “rated unfunded applications just as positively as funded applications.” In their abstract, Pier et al. conclude that “it appeared that the outcome of the [mock] grant review depended more on the reviewer to whom the grant was assigned than the research proposal in the grant.”

From my perspective as a taxpayer, this is head-scratching. But I will leave it to the lay media to explore that point of view, as the New York Times did recently. As a young clinician-scientist, these results are a bit intimidating. But these findings also provide empirical data corroborating what I have heard at every grant-funding workshop I’ve attended—your job as a grant applicant is to communicate clearly and concisely so that intelligent people can understand the impact and validity of your proposed work, regardless of their exact area of expertise. With each rejection I get, either from a journal or a funding agency, I now think about how I could have communicated my message more crisply.

Sure, luck is part of the process. Who you get as a reviewer clearly has some influence on your success. But to paraphrase an axiom I’ve heard many times: The harder I work, the more luck I seem to have.

Christopher Dy, MD, MPH is a hand and peripheral nerve surgeon, an assistant professor at Washington University Orthopaedics, and a member of the JBJS Social Media Advisory Board.

Virtual Reality Makes Foray into Orthopaedics

VR SurgeryVirtual reality (VR) is the computer-generated simulation of a three-dimensional environment that people can interact with in a seemingly real or physical way using special electronic equipment. Though I typically think of its impact on the video game world, the possibilities and applications of this technology are seemingly endless.

In fact, according to a recent article in MedCity News, VR is now being used to help train orthopaedic surgeons. Osso VR, a virtual-reality surgical training platform, hopes to change the way surgeons get trained by harnessing the possibilities of VR. The platform delivers realistic interactive surgical training environments that include the latest procedures and technology. According to pediatric orthopaedist and former game developer Justin Barad, co-founder and CEO of Osso VR, teams and individuals can practice and objectively measure their performance without needing a cadaver or putting any patients at risk while they learn. The technology also helps medical device companies help surgeons gain proficiency in a particular procedure or with a specific technology more quickly than otherwise possible.

Barad cites many problems with the way surgeons currently learn new surgical techniques. They often have to travel to remote cadaver courses for the opportunity to practice in a hands-on way. That model leaves few or no options to practice the procedure and become proficient with it. Barad claims that the model offered by Osso VR provides a new way to practice modern surgical techniques in a hands-on way and has the potential to positively impact surgical outcomes.

VR technology is still new, and orthopaedic educators are just starting to figure out how best to integrate it into orthopaedic education. But those details will likely work themselves out as the technology becomes more familiar to members of the orthopaedic community. Regardless, it is an appealing new tool that may help further bridge the gap between abstract book learning and the reality of patient care.

Nick Schepis
JBJS Social Media & Analytics Specialist

Shoulder Arthroplasty: Doxy + Cefazolin No Better than Cefazolin Alone Against P. Acnes

Doxycycline for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Andrew D. Duckworth, MSc, FRCSEd(Tr&Orth), PhD, in response to a recent study in JBJS.

Propionibacterium acnes (now called Cutibacterium acnes, according to an updated classification) is a ubiquitous microbe in the setting of shoulder surgery and is a well-established cause of indolent infection and prosthetic loosening1,2.  In 2016, JBJS published a study by Hsu et al. investigating single-stage revision shoulder replacement in patients with subclinical infection, and the authors reported that almost half of the patients had >2 positive cultures for P. acnes3.  However, the exact consequence of positive cultures at the time of primary surgery is unknown, and the efficacy of specific antibiotic prophylaxis against this microbe remains unclear.

In the June 6, 2018 issue of JBJS, Rao et al. randomised 56 patients scheduled to undergo a primary anatomic or reverse total shoulder replacement to receive either preoperative cefazolin alone (n=27) or a combination of cefazolin and doxycycline (n=29) 4.  All patients had standard skin preparation at the time of surgery with both alcohol and chlorhexidine.

The primary outcome measure was ≥1positive culture after 14 days of incubation from either superficial and/or deep-tissue samples taken intraoperatively. The authors deemed that a decrease of 50% in the positive culture rate would be clinically significant. However, they found no significant difference between the groups in terms of the primary outcome measure (p=0.99).  The authors carried out a secondary analysis to determine which other factors might be associated with ≥1 positive P. acnes culture and found that younger age, male sex, and a lower Charlson Comorbidity Index were predictive.  Although this study was potentially underpowered, it demonstrated that in patients undergoing primary shoulder arthroplasty, preoperative doxycycline does not significantly reduce the prevalence of positive culture rates for P. acnes.

These findings are similar to those found in previous research and should lead us to question whether preoperative antibiotics aimed specifically at preventing P. acnes infection associated with shoulder arthroplasty are truly useful. P. acnes infections are difficult to detect both clinically and via culture—which makes any intervention difficult to measure, especially in a potentially underpowered study. Consequently, larger studies in this area would help to more definitively determine whether preoperative antibiotics aimed specifically at P. acnes decrease infection rates or, instead, may be adding to the growing problem of bacterial resistance. In particular, such trials seem most useful when they focus on patients who are at higher risk of these specific infections—in this case, younger, healthy males.

Finally, as Rao et al. wisely observed, doxycycline is a bacteriostatic agent, which slows the growth and production of bacteria, rather than a bactericidal agent, which kills bacteria.  Given that antimicrobial limitation, doxycycline might not be the most appropriate prophylactic drug to be investigating for these cases.

Andrew D. Duckworth, MScFRCSEd(Tr&Orth), PhD is a consultant orthopaedic trauma surgeon at Edinburgh Orthopaedic Trauma, Royal Infirmary of Edinburgh, and he is a member of the JBJS Social Media Advisory Board.

References

  1. Gausden EB, Villa J, Warner SJ, Redko M, Pearle A, Miller A, Henry M, Lorich DG, Helfet DL, Wellman DS. Nonunion After Clavicle Osteosynthesis: High Incidence of Propionibacterium acnes.  J Orthop Trauma. 2017 Apr;31(4):229-235.
  2. Chuang MJ, Jancosko JJ, Mendoza V, Nottage WM. The Incidence of Propionibacterium acnes in Shoulder Arthroscopy.  2015 Sep;31(9):1702-7.
  3. Hsu JE, Gorbaty JD, Whitney IJ, Matsen FA III. Single-Stage Revision Is Effective for Failed Shoulder Arthroplasty with Positive Cultures for Propionibacterium. J Bone Joint Surg 2016;98:2047-2051.
  4. Rao AJ, Chalmers PN, Cvetanovich GL, O’Brien MC, Newgren JM, Cole BJ, Verma NN, Nicholson GP, Romeo AA. Preoperative Doxycycline Does Not Reduce Propionibacterium acnes in Shoulder Arthroplasty.  J Bone Joint Surg Am. 2018 Jun 6;100(11):958-964.

Sarcopenia: An Independent Predictor of Mortality in Geriatric Acetabular Fractures

PLVIOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD, in response to a recent study in the Journal of Orthopaedic Trauma.

Fractures in the elderly are a growing problem in developed countries and generally carry a significant morbidity and mortality burden. When considering treatment strategies and making prognoses in this patient population, our ability to stratify patient frailty may be just as or more important than classifying the fracture. In a recent study in the Journal of Orthopaedic Trauma, Mitchell et al. evaluate the role of sarcopenia, an age-related loss of muscle mass, in predicting 1-year mortality among elderly patients with acetabular fractures.1

The authors performed a retrospective review of nearly 150 patients >60 years of age who sustained an acetabular fracture between 2003 and 2014. The authors used the lowest quartile of the psoas:lumbar vertebral index (PLVI) in the cohort as a surrogate for sarcopenia. The PLVI is calculated by measuring the cross-sectional area of the psoas muscle bellies at the L4 level and dividing that number by the cross-sectional area of the L4 vertebral body measured at the superior endplate (see image). Lower PLVIs represent greater loss of muscle mass.

After controlling for confounding variables, the authors found that sarcopenia was an independent risk factor for 1-year mortality. Specifically, patients with sarcopenia had a 32.4% 1-year mortality rate compared to a rate of 11.0% in patients without sarcopenia. Age and injury severity score (ISS) were also predictive of 1-year mortality, and patients with all 3 factors (age >75 years, ISS >14, and sarcopenia) had a mortality rate of 90%.

This article highlights the importance of risk-stratifying patients in ways that account for more than their presenting injuries. In the elderly population, chronologic age is only one of many indicators of frailty. Sarcopenia may be another marker that we can use to better understand the general well-being of our patients. As Mitchell et al. mention, more research must be done to precisely define a PLVI cutoff for sarcopenia to make this index a clinically useful tool. Ultimately, doing so will allow us to offer elderly patients and their families more thoughtful and evidence-based counseling regarding treatment and prognosis.

Matthew Herring, MD is a senior orthopaedic resident at the University of Minnesota and a member of the JBJS Social Media Advisory Board.

Reference

  1. Mitchell, Phillip M., et al., Sarcopenia is Predictive of 1-year Mortality After Acetabular Fractures in Elderly Patients.” Journal of Orthopaedic Trauma, June 2018; 32 (6) : 278-282.

Bunion Treatments Abound Amid Multiple Etiologies

Bunionectomy for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Shahriar Rahman, MS, in response to a recent study in Foot and Ankle Clinics of North America.

It makes sense that orthopaedic conditions with multiple etiologic factors have a corresponding variety of treatment options. So it is with hallux valgus (bunion deformity). In the June 2018 edition of Foot and Ankle Clinics of North America, Smyth and Aiyer1 focus on the pathoanatomy of hallux valgus and various approaches to selecting an operative option.

With more than 100 different operative procedures described to correct hallux valgus, it can be challenging to pick the “right” procedure for each patient. The etiology of hallux valgus includes intrinsic factors (e.g., a long first metatarsal, the shape of the metatarsal head, and soft-tissue imbalances across the hallux metatarsophalangeal [MP] joint) and extrinsic factors (e.g., high-heeled, narrow toe-box shoes). Other kinematic factors of the foot, such as hypermobility of the first ray, are associated with hallux valgus, as is pes planus (flatfoot). Whatever the etiology, hallux valgus almost always progresses in a relatively predictable manner.1

Careful preoperative analysis is required to successfully treat hallux valgus, with the goal of restoring static and dynamic balance around the first MP joint. For optimum outcomes, a soft-tissue procedure (e.g., modified McBride procedure) is now commonly combined with osseous corrective techniques. The chevron osteotomy, which has been modified in multiple ways, achieves acceptable outcomes with reportedly high patient satisfaction levels, as does a percutaneous distal metatarsal osteotomy.2

More severe deformities are usually treated with proximal first metatarsal osteotomies—such as  a proximal chevron, Ludloff osteotomy, or Scarf osteotomy—to increase the possible angular correction of the metatarsal. While these procedures are more “powerful” correction options, some studies have shown recurrence rates up to 30% at 10 years of follow up.1,2 In cases of severe deformity accompanied by arthritis of the tarsometatarsal (TM) joint, a modified Lapidus procedure may be an option for stabilizing the first TM joint. Hallux MP arthrodesis is also considered in patients who have severe deformity, arthritis, and neuromuscular disorders, and for the revision of a previously failed hallux valgus surgery.

There is currently no consensus as to which procedure is the gold standard for treating hallux valgus. Despite multiple comparative studies assessing the outcomes of different techniques, the decision ultimately depends on surgeon and patient preferences.

Shahriar Rahman, MS is a consultant orthopaedic surgeon at the Ministry of Health & Family Welfare in Bangladesh and a member of the JBJS Social Media Advisory Board.

References

  1. Smyth NA & Aiyer AA 2018, ‘Introduction: Why Are There so Many Different Surgeries for Hallux Valgus?’, Foot and Ankle Clinics, 23, no.2, pp.171-182.
  2. Adams SB, 2017, JBJS Clinical Summary: Hallux Valgus (Bunion Deformity), viewed 27 may 2018, https://jbjs.org/summary.php?id=188

Related Articles from JBJS Essential Surgical Techniques

Predicting Failure of Femoral Neck Fixation

Femoral Neck Fracture for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD, in response to a recent study in the Journal of Orthopaedic Trauma.

With many problems in orthopaedics, the best management options are still being debated. The treatment of femoral neck fractures is one such problem. Surgeons have several available options: cancellous screws (CS), a sliding hip screw (SHS), hemiarthroplasty, and total hip arthroplasty. The recently completed Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) randomized trial sought to offer insight on those treatment modalities.1 The study enrolled 1,079 patients with low-energy femoral neck fractures and randomized them into treatment with CS or SHS.

In a follow-up study published in the May 2018 edition of the Journal of Orthopedic Trauma, Sprague et al. analyzed FAITH data to identify predictors of revision surgery during 24 months after surgical fixation of a femoral neck fracture.2 Based on previously published studies, the authors identified 15 factors a priori that may be associated with revision surgery . Among the more than 800 patients in the FAITH cohort who had complete follow-up data, 191 (23%) underwent revision surgery and were included in the analysis. Proportional hazard modeling identified 5 factors associated with revision surgery: female sex (hazard ratio [HR], 1.79), body mass index (HR, 1.19—a 19% increased risk of revision for every 5-point increase in BMI), displaced fracture (HR, 2.16), Pauwels type III configuration (HR, 2.13 relative to type II), and poor implant positioning (HR, 2.70). In addition, prefracture dependence on assistive devices for ambulation was significantly associated with a risk of conversion to arthroplasty (p = 0.04), although a hazard ratio was not reported.

These important findings may help guide our decision making for the treatment of femoral neck fractures. First, male patients may be better candidates for surgical fixation of neck fractures than female patients, which probably relates to sex differences in bone density. Thinner patients also may be better candidates for femoral neck fixation, while arthroplasty may be the more reliable option for high-BMI patients.

Second, we have to pick the right fractures to fix. As is well described elsewhere in the literature, a more vertical fracture line (>50°) is more likely to fail with fixation. Additionally, patients with displaced fractures face a significantly higher risk of revision surgery and may be poor candidates for fixation.

Arguably, the most important modifiable risk factor for revision surgery is surgical technique. Unfortunately (and fortunately), in the FAITH study there were too few malreductions to investigate this variable in detail. However, poor implant positioning—defined as prominent screws at the lateral cortex, screw penetration, and lag screws positioned too high—was strongly associated with an increased risk of revision surgery.

It goes without saying, but well-placed implants perform better.

Matthew Herring, MD is a senior orthopaedic resident at the University of Minnesota and a member of the JBJS Social Media Advisory Board.

References

  1. Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) Investigators. Fracture fixation in the operative management of hip fractures (FAITH): an international, multicentre, randomised controlled trial. Lancet. 2017;389(10078):1519-1527.
  2. Sprague S, Schemitsch EH, Swiontkowski M, et al. Factors Associated With Revision Surgery After Internal Fixation of Hip Fractures. J Orthop Trauma. 2018;32(5):223-230.

Addressing the Gender Gap in Orthopaedics

Female Orthos for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Megan Conti Mica, MD, in response to the 2018 Medscape Orthopaedist Compensation Report.

In a recently published Medscape survey looking at orthopaedic compensation,  orthopods were the second-highest paid specialists overall. Despite that, only 51% of orthopaedist respondents to the Medscape survey felt they were fairly compensated. My question to you is: How fairly compensated would orthopods feel if that second-highest salary was decreased by $150,000 annually without reason?

While the reported overall wage gap between female and male physicians is more than $50,000 annually1, the Medscape survey found that the gender wage difference for orthopaedic surgeons was $143,000 annually—adding injury to insult. That annual gap would amount to $4 million of lost wages for women over a 30-year career as an orthopaedic surgeon.

Why does medicine in general and orthopaedics in particular have a gender gap?  Is it because male surgeons have better outcomes than female surgeons?  Not according to a 2017 study that found that patients of female surgeons experienced lower death rates, fewer complications, and fewer 30-day readmissions to the hospital, compared with patients of male surgeons.2 While I do not believe that gender alone makes one a better surgeon, I do believe that gender diversity within our field is imperative.

What is more disheartening is it seems no one with the power to make change is doing anything to close the gap. In 2009, only 4% of the AAOS fellows were female. Honestly, I cannot blame women for not trying to join the “boys club.”  If someone told you that you would be a distinct minority in your profession, make less, and have to work harder, most rational human beings would find a different career.  If we want more women in orthopaedics, we need to understand that the gender wage gap is just the surface of a bigger issue.

I challenge everyone (men and women) to do better. Help your female partners. Be more attentive and mentor female surgeons. Support women when they speak up, and champion for them when they don’t. The attributes that make a great orthopaedic surgeon—love of and dedication to this great specialty—are gender-neutral.

Megan Conti Mica, MD is a hand and upper-extremity surgeon at the University of Chicago Medical Center and a member of the JBJS Social Media Advisory Board.

References

  1. JAMA Intern Med. 2016;176(9):1294-1304. doi: 10.1001/jamainternmed.2016.3284
  2. BMJ 2017;359:j4366, Published 10 October 2017. doi: 10.1136/bmj.j4366

Horseshoes and Total Knee Arthroplasty

TKA Alignment for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD, in response to a recent JBJS article.

The old adage that “close only counts in horseshoes” may also apply to total knee arthroplasty (TKA). Much attention has been paid to coronal alignment during TKA based on conventional wisdom that prosthetic durability and patient function are strongly dependent on that parameter. To re-check that hypothesis, in the March 21, 2018 issue of JBJS, Abdel et al. evaluated the influence of coronal plane alignment on implant survival by analyzing results from a large cohort of patients who underwent primary TKA 20 years ago.

In 2010, Abdel’s group reviewed a consecutive series of 398 primary cemented TKAs done between 1985 and 1990. Knees were divided into 2 groups based on their mechanical alignment as measured using a full-length hip-knee-ankle radiograph. Knees in the “aligned group” (n = 292) were defined as having alignment within 0° ± 3° of the mechanical axis, and knees in the “outlier group” (n = 106)  were defined as having alignment >3° in varus or valgus. Implant survival was evaluated based on the need for revision, and the specific indications for revisions were recorded.

In the current study, at 20 years of follow-up, the authors found revision rates that were not significantly different between the same 2 groups—19.5% in the mechanically aligned group and 15.1% in the outliers. Multivariate analysis controlling for patient age and BMI did not demonstrate any implant survivorship benefit for the mechanically well aligned group as compared to the outliers.

This study seems to call into question the dogma that a neutral mechanical axis protects against mechanical failure. The effort, time, and money spent on techniques and devices to improve coronal plane alignment by a few degrees (i.e., computer navigation, custom jigs, and robotics) may not translate into meaningful improvements in patient outcomes.

It is important to note that in this group’s 2010 study evaluating the same cohort, 66% of knees in the outlier group were only 4° shy of neutral and only 12% (13 knees) were >6° off. So, while we should still strive for neutral mechanical alignment, it seems that we may miss the neutral mark by a few degrees without harming our patients.

Matthew Herring, MD is a senior orthopaedic resident at the University of Minnesota and a member of the JBJS Social Media Advisory Board.

Aspirin Noninferior to Rivaroxaban for Anticoagulation after Joint Replacement

Aspirin for OBuzzOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Amir Khoshbin, MD in response to a recent randomized trial in the New England Journal of Medicine.

The ideal anticoagulation protocol for patients who have received a total knee or hip replacement remains controversial. Results from the recently published “Extended Venous Thromboembolism Prophylaxis Comparing Rivaroxaban to Aspirin Following Total Hip and Knee Arthroplasty (EPCAT) II” trial add some clarity to this topic.

This large double-blind, randomized noninferiority trial compared two outpatient anticoagulation regimens after elective unilateral primary or revision hip or knee arthroplasty. Almost 3,500 patients were enrolled, and they all received 10 mg of rivaroxaban daily until postoperative day five. After that, 1,707 patients were randomized to receive 81 mg of aspirin daily, while the remaining 1,717 patients received 10 mg of rivaroxaban daily. Per previous recommendations, total knee arthroplasty patients received anticoagulation for a total of 14 days, and total hip arthroplasty patients continued anticoagulation for 30 days.

Twelve patients in the rivaroxaban group (0.7%) had a venous thromboembolism event in the 90-day postsurgical period, versus 11 patients (0.64%) in the aspirin group (p >0.05). In terms of complications from anticoagulation treatment, 5 patients (0.29%) in the rivaroxaban group and 8 patients in the aspirin group (0.47%) had a major bleeding event (p >0.05).  It is worth noting that there were multiple different implants, approaches, and perioperative protocols followed in the study. Also, very few patients with a history of venous thromboembolism (81 patients, 2.4%), cancer (80 patients, 2.3%) or smoking (319 patients, 9.3%) were included in the study. These patients would be considered at higher risk for venous thromboembolism after joint replacement.

These limitations notwithstanding, the results from prophylaxis with aspirin after an initial five days of rivaroxaban were not significantly different from results with continued rivaroxaban. Institutional prices vary, but in this time of bundled care, the financial implications of studies like this one could be great. Anecdotally, in our institution the price of rivaroxaban is 140 times that of aspirin.

This is not the first study whose findings support the use of aspirin for venous thromboembolism prophylaxis, but it is one of the largest. It appears that such findings are starting to change the practice of some orthopaedic surgeons. We expect that additional large studies will provide further insight into this question.

Amir Khoshbin, MD is an assistant professor of orthopaedics at the University of Toronto and a member of the JBJS Social Media Advisory Board. He can be reached at khoshbinam@smh.ca.