Nationwide Analysis of Lower Extremity Periprosthetic Fractures.

BACKGROUND: Although the annual incidence of primary total joint arthroplasty is increasing, trends in the annual incidence of periprosthetic fractures have not been established. This study aimed to define the annual incidence of periprosthetic fractures in the United States. METHODS: Inpatient admission data for 60,887 surgically treated lower extremity periprosthetic fractures between 2006 and 2015 were obtained from the National Inpatient Sample database. The annual incidence of periprosthetic fractures was defined as the number of new cases per year and presented as a population-adjusted rate per 100,000 US individuals. Univariable methods were used for trend analysis and comparisons between groups. RESULTS: The national annual incidence of periprosthetic fractures presented as a population-adjusted rate of new cases per year peaked in 2008 (2.72; 95% confidence interval [95% CI], 2.39-3.05), remained stable from 2010 (1.65; 95% CI, 1.45-1.86) through 2013 (1.67; 95% CI, 1.55-1.8) and increased in 2014 (1.99; 95% CI, 1.85-2.13) and 2015 (2.47; 95% CI, 2.31-2.62). The proportion of femoral periprosthetic fractures managed with total knee arthroplasty revision remained stable (Ptrend = .97) with an increase in total hip arthroplasty (THA) revision (Ptrend < .001) and concurrent decrease in open reduction and internal fixation (ORIF) (Ptrend < .001). Revision THA was significantly more costly than revision total knee arthroplasty (P = .004), and both were significantly more costly than ORIF (P < .001 for both). CONCLUSION: The annual incidence of periprosthetic fractures remained relatively stable throughout our study period. The proportion of periprosthetic fractures managed with revision THA increased, whereas ORIF decreased. Our findings are encouraging considering the significant burden an increase in periprosthetic fracture incidence would present to the health care system in terms of both expense and patient morbidity.

Preoperative Allergy Testing for Patients Reporting Penicillin and Cephalosporin Allergies is Cost-Effective in Preventing Infection after Total Knee and Hip Arthroplasty.

BACKGROUND: Routine preoperative allergy testing in patients reporting penicillin and cephalosporin allergies increases the number able to receive cefazolin, which should reduce the risk of infection after total knee and hip arthroplasty (TKA/THA), but it remains unclear whether this practice is cost-effective. Using a break-even analysis, we calculated the cost-effectiveness of routine preoperative allergy testing for infection prevention in total joint arthroplasty patients reporting penicillin and cephalosporin allergies. METHODS: The cost of a penicillin allergy evaluation, the cost of revision arthroplasty for prosthetic joint infection (PJI), and baseline rates of PJI in patients receiving a noncefazolin antibiotic in the perioperative period were derived from existing literature. A break-even economic model using these variables was constructed to calculate the absolute risk reduction (ARR) in infection rate needed for preoperative allergy testing to be cost-effective. The number needed to treat (NNT) was calculated from the ARR. RESULTS: Preoperative allergy testing before TKA and THA in patients reporting penicillin and cephalosporin allergies was cost-effective if the initial infection rate decreased by an ARR of 0.810% (NNT = 123) and 0.655% (NNT = 153) for TKA and THA, respectively. Cost-effectiveness was maintained with varying allergy consultation costs, infection rates, and costs associated with PJI treatment. CONCLUSION: Routine preoperative allergy testing and clearance are cost-effective infection prevention strategies among patients reporting penicillin and cephalosporin allergies in the setting of elective joint arthroplasty. Widespread adoption of this practice may considerably reduce the economic and societal burden associated with prosthetic infections.

The Cost-Effectiveness of Silver-Impregnated Occlusive Dressings for Infection Prevention After Total Joint Arthroplasty.

BACKGROUND: Prosthetic joint infection (PJI) is a catastrophic complication after total joint arthroplasty that exacts a substantial economic burden on the health-care system. This study used break-even analysis to investigate whether the use of silver-impregnated occlusive dressings is a cost-effective measure for preventing PJI after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA). METHODS: Baseline infection rates after TKA and THA, the cost of revision arthroplasty for PJI, and the cost of a silver-impregnated occlusive dressing were determined based on institutional data and the existing literature. A break-even analysis was then conducted to calculate the minimal absolute risk reduction needed for cost-effectiveness. RESULTS: The use of silver-impregnated occlusive dressings would be economically viable at an infection rate of 1.10%, treatment costs of $25,692 for TKA PJI, and $31,753 for THA PJI and our institutional dressing price of $38.05 if it reduces infection rates after TKA by 0.15% (the number needed to treat [NNT] = 676) and THA by 0.12% (NNT = 835). The absolute risk reduction needed to maintain cost-effectiveness did not change with varying initial infection rates and remained less than 0.40% (NNT = 263) for infection treatment costs as low as $10,000 and less than 0.80% (NNT = 129) for dressing prices as high as $200. CONCLUSION: The use of silver-impregnated occlusive dressings is a cost-effective measure for infection prophylaxis after TKA and THA.

Online Crowdsourcing to Explore Public Perceptions of Robotic-Assisted Orthopedic Surgery.

BACKGROUND: The clinical benefits of robotic-assisted technology in total joint arthroplasty are unclear, but its use is increasing. This study employed online crowdsourcing to explore public perceptions and beliefs regarding robotic-assisted orthopedic surgery. METHODS: A 30-question survey was completed by 588 members of the public using Amazon Mechanical Turk. Participants answered questions regarding robotic-assisted orthopedic surgery, sociodemographic factors, and validated assessments of health literacy and patient engagement. Multivariable logistic regression modeling was used to determine population characteristics associated with preference for robotic technology. RESULTS: Most respondents believe robotic-assisted surgery leads to better results (69%), fewer complications (69%), less pain (59%), and faster recovery (62%) than conventional manual methods. About half (49%) would prefer a low-volume surgeon using robotic technology to a high-volume surgeon using conventional manual methods. The 3 main concerns regarding robotic technology included lack of surgeon experience with robotic surgery, robot malfunction causing harm, and increased cost. Only half of respondents accurately understand the actual role of the robot in the operating room. Overall, 34% of participants have a clear preference for robotic-assisted surgery over a conventional manual approach. After multivariable regression analysis, Asian race, working in healthcare, early technology adoption, and prior knowledge of robotic surgery were independent predictors of preferring robotic-assisted surgery. CONCLUSION: The public's unawareness of the dubious outcome superiority associated with robotic-assisted orthopedic surgery may contribute to misinformed decisions in some patients. Robotic-assisted technology appears to be a powerful marketing tool for surgeons and hospitals.

The Calpain Gene is Correlated With Metal-on-Metal Hip Replacement Failures.

BACKGROUND: Metal-on-metal (MOM) total hip arthroplasty is associated with unacceptable failure rates secondary to metal ion reactions. Efforts to identify which patients will go on to failure have been limited; recently, there has been a suggestion for a potential genetic basis for the increased risk of revision in MOM hip replacements (MOMHRs). The purpose of this study is to determine whether certain immunologic genotypes are predictive of the need for revision in patients with MOM total hip implants. METHODS: This is a case-control study of all patients undergoing primary MOMHR between September 2002 and January 2012 with a minimum of 5-year follow-up. Our investigational "case" cohort was comprised of patients who underwent revision for MOMHR for a reason other than infection. A single-nucleotide polymorphism (SNP) array analysis was performed to identify a potential genetic basis for failure. RESULTS: Thirty-two patients (15 case and 17 control) were included in our analysis. All patients in the revision group had a chief complain of pain; revision patients were more likely to have a posterior approach (P = .01) and larger head size (P = .04) than nonrevision patients. No patient or implant characteristics were independently associated with revision in a multivariate analysis. Patients with SNP kgp9316441 were identified as having an increased odds of revision for MOM failure (P < .001). CONCLUSION: This study identified an SNP, kgp9316441, encoding proteins associated with inflammation and macrophage activation. This SNP was associated with significantly increased odds of revision for MOMHR. Future studies are warranted to validate this gene target both in vitro and in vivo. LEVEL OF EVIDENCE: III.

Donning Gloves Before Surgical Gown Eliminates Sleeve Contamination.

BACKGROUND: There are numerous studies in the literature that have recognized the importance of the glove-gown interface as a potential source of intraoperative bacterial contamination. It has been demonstrated that the methods with which one dons their surgical gown and gloves can alter the level of gown contamination. We hypothesize that donning undergloves before the surgical gown will decrease if not eliminate sleeve contamination. METHODS: We performed a comparative study to assess the differences in gown contamination between three different gown and glove donning techniques. Participants ranged in experience level from intern to attending. Each participant covered their hands with ultraviolet light disclosing lotion and then donned surgical gown and gloves with their preferred technique and with the proposed technique in a randomly assigned order. The gowns were then removed and analyzed under ultraviolet light for distance and quantity of sleeve contamination. RESULTS: The gloves-first technique demonstrated zero contamination in all samples. This is significantly less than both closed and open staff-assisted techniques (P < .0001). All samples of closed and open techniques demonstrated some level of contamination. The distance of contamination on the right sleeve is significantly greater than the left sleeve (P < .0001). DISCUSSION: The gloves-first technique demonstrates zero sleeve contamination throughout all samples, regardless of the experience level. We strongly recommend considering the use of this glove and gown donning technique as opposed to the currently accepted closed and open techniques in an effort to reduce gown contamination.

Polymicrobial Infections in Hip Arthroplasty: Lower Treatment Success Rate, Increased Surgery, and Longer Hospitalization.

BACKGROUND: Polymicrobial hip arthroplasty infections are a subset of periprosthetic joint infection (PJI) with distinct challenges representing 10%-47% of PJI. METHODS: Records were reviewed from all PJIs involving partial or total hip arthroplasty with positive hip cultures between 2005 and 2015 in order to determine baseline characteristics and outcomes including treatment success, surgeries for infection, and days in hospital for infection. Analysis was restricted to patients who had at least 2 years of follow-up after their final surgery or hospitalization for infection. Factors with P-value less than .05 in univariate outcomes analysis were included in multivariable models. RESULTS: After multivariable analysis, 28 of 95 hip arthroplasty PJIs which were polymicrobial were associated with significantly lower treatment success, more surgery, and longer hospitalizations compared to PJIs which were not polymicrobial. Patients diagnosed with polymicrobial infection later in treatment (4 of 28) had the lowest treatment success rate, underwent the most surgery, and spent the longest time in hospital. CONCLUSION: Polymicrobial periprosthetic hip infection is a particularly devastating complication of hip arthroplasty associated with decreased likelihood of treatment success, increased surgery for infection, and greater time in hospital. Patients with late polymicrobial infection had the worst outcomes. This investigation further characterizes the natural history of periprosthetic hip infections with more than one infectious organism. Patients who present with a subsequent polymicrobial infection should be educated that they have a particularly difficult treatment course and treatment success may not be possible.

Saphenous Nerve Block From Within the Knee Is Feasible for TKA: MRI and Cadaveric Study.

BACKGROUND: Surgeon-performed periarticular injections and anesthesiologist-performed femoral nerve or adductor canal blocks with local anesthetic are in common use as part of multimodal pain management regimens for patients undergoing TKA. However, femoral nerve blocks risk causing quadriceps weakness and falls, and anesthesiologist-performed adductor canal blocks are costly in time and resources and may be unreliable. We investigated the feasibility of a surgeon-performed saphenous nerve ("adductor canal") block from within the knee at the time of TKA. QUESTIONS/PURPOSES: (1) Can the saphenous nerve consistently be identified distally on MRI studies, and is there a consistent relationship between the width of the femoral transepicondylar axis (TEA) and the proximal (cephalad) location where the saphenous nerve emerges from the adductor canal? With these MRI data, we asked the second question: (2) Can we utilize this anatomic relationship to simulate a surgeon-performed intraoperative block of the distal saphenous nerve from within the knee with injections of dyes after implantation of trial TKA components in cadaveric lower extremity specimens? METHODS: A retrospective analysis of 94 thigh-knee MRI studies was performed to determine the relationship between the width of the distal femur at the epicondylar axis and the proximal location of the saphenous nerve after its exit from the adductor canal and separation from the superficial femoral artery. These studies, obtained from one hospital's MRI library, had to depict the saphenous nerve in the distal thigh and the femoral epicondyles and excluded patients younger than 18 years of age or with metal implants. These studies were performed to evaluate thigh and knee trauma or unexplained pain, and 55 had some degree of osteoarthritis. After obtaining these data, TKA resections and trial component implantation were performed, using a medial parapatellar approach, in 11 fresh cadaveric lower extremity specimens. There were six male and five female limbs from cadavers with a mean age of 70 years (range, 57-80 years) and mean body mass index of 20 kg/m (range, 15-26 kg/m) without known knee arthritis. Using a blunt-tipped 1.5-cm needle, we injected 10 mL each of two different colored solutions from inside the knee at two different locations and, after 30 minutes, dissected the femoral and saphenous nerves and femoral artery from the hip to the knee. Our endpoints were whether the saphenous nerve was bathed in dye and if the dye or needle was located in the femoral artery or vein. RESULTS: Based on the MRI analysis, the mean ± SD TEA was 75 ± 4 mm in females and 87 ± 4 mm in males. The saphenous nerve exited the adductor canal and was located at a mean of 1.5 ± 0.16 times the TEA width in females and a mean of 1.3 ± 0.13 times the TEA width in males proximal to the medial epicondyle. After placement of TKA trial components and injection, the proximal injection site solution bathed the saphenous nerve in eight of 11 specimens. In two cachectic female cadaver limbs, the dye was located posteriorly to the nerve in hamstring muscle. The proximal blunt needle and colored solution were directly adjacent to but did not penetrate the femoral artery in only one specimen. CONCLUSIONS: This study indicates, based on MRI measurements, cadaveric injections, and dissections, that a surgeon-performed injection of the saphenous nerve from within the knee after it exits from the adductor canal seems to be a feasible procedure. CLINICAL RELEVANCE: This technique may be a useful alternative to an ultrasound-guided block. A trial comparing surgeon- and anesthesiologist-performed nerve block should be considered to determine the clinical efficacy of this procedure.

Common Medical Comorbidities Correlated With Poor Outcomes in Hip Periprosthetic Infection.

BACKGROUND: Periprosthetic infection has been linked to risk factors such as diabetes, obesity, and smoking among others. This study examined the relationship between common patient comorbidities and hip periprosthetic infection outcomes. METHODS: We retrospectively reviewed the records of 149 culture-positive periprosthetic hip infections at our tertiary care center that underwent treatment between 2005 and 2015. Baseline characteristics and common comorbidities were analyzed with relation to rates of successfully treated infection, total surgeries for infection, and cumulative length of hospitalization using multivariate analysis. RESULTS: Patients with coronary artery disease or anemia had significantly lower rate of successfully treated infection. Patients with anemia or chronic pulmonary disease underwent significantly more surgery, and patients with chronic pulmonary disease, psychiatric disease, anemia, or diabetes spent significantly longer time in hospital. CONCLUSION: Potentially modifiable cardiovascular, respiratory, and psychiatric diseases were associated with a decreased rate of successfully treated infection, more surgery, and longer hospitalization in treatment for hip periprosthetic infection in multivariate analysis.

Specific Infectious Organisms Associated With Poor Outcomes in Treatment for Hip Periprosthetic Infection.

BACKGROUND: Periprosthetic hip infection treatment remains a significant challenge for orthopedics. Some studies have suggested that methicillin resistance and gram-negative organism type are associated with increased treatment failure. The aim of this research is to determine if specific organisms were associated with poor outcomes in treatment for hip periprosthetic infection. METHODS: Records were reviewed of all patients between 2005 and 2015 who underwent treatment for infected partial or total hip arthroplasty. Characteristics of each patient's treatment course were determined including baseline characteristics, infecting organism(s), infection status at final follow-up, surgeries for infection, and time in hospital. Baseline characteristics and organisms that were associated with clinical outcomes in univariate analysis were incorporated into multivariable outcomes models. RESULTS: When compared with patients infected with other organism(s), patients infected with the following organisms had significantly decreased infection-free rates: Pseudomonas, methicillin-resistant Staphylococcus aureus (MRSA), and Proteus. Infection with certain organisms was associated with 1.13-2.58 additional surgeries: methicillin-sensitive S aureus, coagulase-negative Staphylococcus, MRSA, Pseudomonas, Peptostreptococcus, Klebsiella, Candida, diphtheroids, Propionibacterium acnes, and Proteus species. Specific organisms were associated with 8.56-24.54 additional days in hospital for infection: methicillin-sensitive S aureus, coagulase-negative Staphylococcus, Proteus, MRSA, Enterococcus, Pseudomonas, Klebsiella, beta-hemolytic Streptococcus, and diphtheroids. Higher comorbidity score was also associated with greater length of hospitalization. CONCLUSION: MRSA, Pseudomonas, and Proteus were associated with all 3 outcomes of lower infection-free rate, more surgery, and more time in hospital in treatment for hip periprosthetic infection. Organism-specific outcome information may help individualize patient-physician discussions about the expected course of treatment for hip periprosthetic infection.

Cultural Nuance in Orthopedic Foreign Aid: Differences in Patient Concerns.

Orthopedic aid to developing nations is expanding and becoming a unique facet of the specialty. This investigation seeks to compare patient impressions and concerns regarding the care patients receive as part of an itinerant surgical aid trip in 2 nations. In 2013 and 2014, patients from 2 separate nations completed a Likert scale survey assessing impressions of the care they received at the hands of a surgical team from abroad. Mean response scores were calculated and compared using a t test. This is the first investigation to compare patient concerns across 2 nations in a surgical aid trip setting. The results highlight the importance of culture in understanding patients and the impressions of the care they receive.

Concerns of an itinerant surgeon: results of a Guatemalan surgical aid trip.

Over the past decade the popularity of foreign medical aid has increased and gained notoriety. Operation Walk is a philanthropic organization dedicated to improving the ambulatory potential of patients in developing countries by providing free surgical treatment for patients who otherwise lack access to care of debilitating bone and joint conditions. During Operation Walk Mooresville's 2013 trip to Guatemala 40 patients prospectively completed a Likert Scale style survey. The 63-question survey assessed patient impressions and concerns regarding the care they receive as part of itinerant surgical aid trips. Mean scores were calculated and then concerns were ranked accordingly. We are aware of no other investigation assessing these sorts of patient centered perspectives for international surgical aid trips.

Primary and revision anterior supine total hip arthroplasty: an analysis of complications and reoperations.

Anterior total hip arthroplasty (THA) has been touted by some as a muscle-sparing, less invasive procedure. Reports have focused on the high intraoperative and postoperative complication rates, the increased transfusion risk, and its questionable clinical benefits. The senior author's experience regarding complications and reoperations that occurred after primary and revision THA using an anterior supine intermuscular approach has been generally favorable. An electronic database was used to identify 906 patients treated with 1,035 consecutive anterior supine intermuscular THAs performed by a single surgeon between January 2007 and December 2010, which included 986 primary THAs, 2 resurfacings, 2 conversions of failed open reduction and internal fixation for fracture, and 45 revision THAs. The surgical technique used an anterior approach with a modified Smith-Petersen interval and was performed with the patient supine on a standard operating table without traction. The transfusion rate was 5%. There were three intraoperative calcar cracks and one canal perforation, which was treated with cerclage cables. Four wound complications required débridement, four hips had substantial lateral femoral cutaneous nerve paresthesias that had not resolved by the 12-month follow-up, and one femoral nerve palsy was reported. At up to 40 month's follow-up, there have been 25 revisions (2.4%), including 9 periprosthetic femoral fractures; 1 stem subsidence; 4 hips with aseptic loosening; 5 metal-on-metal bearing complications; 1 cup malpositioning, which was corrected the same day; 4 dislocations; and 1 infection. This 4-year experience with primary and revision anterior THAs has showed acceptable rates of perioperative transfusion, complications, and revisions.

Nutrition in Surgery: An Orthopaedic Perspective.

➤ Malnutrition is common among subsets of patients undergoing orthopaedic surgery and is associated with an increased risk of postoperative complications.➤ Serum proteins, in particular, albumin, may be used in the evaluation of nutritional status.➤ Anthropometric measurements and surveys also play a role in the evaluation of nutritional status.➤ Increased energy and nutrient requirements due to surgical procedures necessitate increased caloric and protein intake in the perioperative period, which may be achieved through diet or supplementation.➤ Evidence supports the use of protein-calorie, amino acid, and immunonutrition supplements. Vitamin D supplementation is an area of further consideration.➤ Diet restriction, activity alterations, pharmacotherapy, and bariatric surgery are all safe, effective approaches to weight loss, although the optimal timing and magnitude of preoperative weight loss require further investigation.

National Decline in Knee Fusions Performed for Salvage of Chronic Periprosthetic Total Knee Infections.

The primary purpose of this study was to study and compare rates of two salvage operations for patients with chronically infected total knee arthroplasties: (1) knee arthrodesis and (2) above knee amputation (AKA). An analysis was performed comparing the inpatient hospital characteristics and complications between the two procedures. Secondarily, we presented rates of all surgically treated periprosthetic total knee infections over a 6-year period. Using the Nationwide Inpatient Sample, we identified all patients with a periprosthetic infection (International Classification of Diseases, Ninth Revision [ICD-9] 996.66) from 2009 to 2014. Subsequently, we identified surgically treated total knee infections through the following ICD-9 codes: 00.80 (all component revision), 00.84 (liner exchange), 80.06 (removal of prosthesis), 84.17 (AKA), and 81.22 (knee fusion). From 2009 to 2014, the annual incidence of surgically treated total knee periprosthetic infections increased by 34.9% nationally, while the annual incidence of primary total knees increased by only 13.9%. Salvage operations (AKA and knee fusion) represented 5.8% of all surgically treated infections. The rate of knee fusions decreased from 1.9% of surgically treated infections in 2009 to 1.4% in 2014 (p < 0.05), while the rate of AKA stayed steady at 4.5% of cases over the 6-year period. Length of stay was significantly shorter in the knee fusion group (7.9 vs. 10.8 days, p < 0.05), but total hospital costs were higher (33,016 vs. 24,933, p < 0.05). In the multivariable adjusted model, patients undergoing knee fusion had significantly decreased odds of being discharged to skilled nursing facility (odds ratio: 0.42, 95% confidence interval: 0.31-0.58). The annual incidence of surgically treated periprosthetic total knee infections is increasing. The rate of knee arthrodesis for chronic periprosthetic total knee infections is decreasing. Reasons for this downward trend in knee fusions should be evaluated carefully as knee fusions have shown to have the potential advantage of improved mobility and decreased patient morbidity for chronic PJI. The level of evidence is III.

The Cost-Effectiveness of Closed Incisional Negative Pressure Wound Therapy for Infection Prevention after Revision Total Knee Arthroplasty.

Recent investigations have shown that closed incisional negative pressure wound therapy (ciNPWT) decreases the rate of postoperative wound complications following revision total knee arthroplasty (TKA). In this study, we used a break-even analysis to determine whether ciNPWT is a cost-effective measure for reducing prosthetic joint infection (PJI) after revision TKA. The cost of ciNPWT, cost of treatment for PJI, and baseline infection rates following revision TKA were collected from institutional data and the literature. The absolute risk reduction (ARR) in infection rate necessary for cost-effectiveness was calculated using break-even analysis. Using our institutional cost of ciNPWT ($600), this intervention would be cost-effective if the initial infection rate of revision TKA (9.0%) has an ARR of 0.92%. The ARR needed for cost-effectiveness remained constant across a wide range of initial infection rates and declined as treatment costs increased. The use of ciNPWT for infection prevention following revision TKA is cost-effective at both high and low initial infection rates, across a broad range of treatment costs, and at inflated product expenses.

Patient Engagement Technologies in Orthopaedics: What They Are, What They Offer, and Impact.

The modern era is an increasingly digital and connected world. Most of the Americans now use a smartphone irrespective of age or income level. As smartphone technologies become ubiquitous, there is tremendous interest and growth in mobile health applications. One segment of these new technologies are the so-called patient engagement platforms. These technologies present a host of features that may improve care. This article provides an introduction to this growing technology sector, offers insight into what they may offer patients and surgeons, and discusses how to evaluate various platforms.

Nuclear Medicine Scans in Total Joint Replacement.

¼: A 3-phase bone scan is a potential first-line nuclear medicine study for pain after total joint arthroplasty (TJA) when there is concern for periprosthetic joint infection or aseptic loosening. ¼: In patients who have a positive bone scintigraphy result and suspected infection of the joint, but where aspiration or other studies are inconclusive, labeled leukocyte scintigraphy with bone marrow imaging may be of benefit. ¼: Magnetic resonance imaging (MRI), while not a nuclear medicine study, also shows promise and has the advantage of providing information about the soft tissues around a total joint replacement. ¼: Radiotracer uptake patterns in scintigraphy are affected by the prosthesis (total knee arthroplasty [TKA] versus total hip arthroplasty [THA]) and the use of cement. ¼: Nuclear medicine scans may be ordered 1 year postoperatively but may have positive findings that are due to normal physiologic bone remodeling. Nuclear studies may be falsely positive for up to 2 years after TJA. ¼: Single-photon emission computed tomography (SPECT) combined with computed tomography (CT) (SPECT/CT), fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT, and MRI show promise; however, more studies are needed to better define their role in the diagnostic workup of pain after TJA.

A break-even analysis of tranexamic acid for prevention of periprosthetic joint infection following total hip and knee arthroplasty.

PURPOSE: Despite the commonplace use of tranexamic acid in total joint arthroplasty, much of the current data regarding its cost-effectiveness examines savings directly related to its hemostatic properties, without considering its protective effect against periprosthetic joint infections. Using break-even economic modeling, we calculated the cost-effectiveness of routine tranexamic acid administration for infection prevention in total joint arthroplasty. MATERIALS AND METHODS: The cost of intraoperative intravenous tranexamic acid, the cost of revision arthroplasty for periprosthetic joint infections, and the baseline rates of periprosthetic joint infections in patients who did not receive intraoperative tranexamic acid were obtained from the literature and institutional purchasing records. Break-even economic modeling incorporating these variables was performed to determine the absolute risk reduction in infection rate to make routine intraoperative tranexamic acid use economically justified. The number needed to treat was calculated from the absolute risk reduction. RESULTS: Routine use of intraoperative tranexamic acid is economically justified if it prevents at least 1 infection out of 3125 total joint arthroplasties (absolute risk reduction = 0.032%). Cost-effectiveness was maintained with varying costs of tranexamic acid, infection rates, and periprosthetic joint infection costs. CONCLUSION: The routine use of intraoperative tranexamic acid is a highly cost-effective practice for infection prevention in primary and revision total joint arthroplasty. The use of tranexamic acid is warranted across a wide range of costs of tranexamic acid, initial infection rates, and costs of periprosthetic joint infection treatment.