Isolated Liner Exchange Versus All-Component Revision for Instability After Total Knee Arthroplasty.

BACKGROUND: Instability is a common cause for revision total knee arthroplasty (TKA). The risks and benefits of polyethylene liner exchange (LE) as compared to full metal component revision continue to be debated. The purpose of this study was to investigate the success rate and complication profiles of revision TKA for instability based on surgical procedure. METHODS: This was a retrospective study of patients undergoing revision TKA for instability from 2015 to 2019. Patients with prior revisions were excluded. 42 patients undergoing isolated polyethylene LE without an increase in constraint were compared with 48 patients undergoing full component revision revision (FCR) of both tibial and femoral components. The primary outcome was differences in rerevision for instability. Noninstability reoperations, 90-day readmissions, and lengths-of-stay were also compared. RESULTS: LEs had a 10.1% higher rerevision for instability rate that approached statistical significance (LE 14.3% versus FCR 4.2%, P = .092). Additionally, FCR had a 4.2% rate of aseptic loosening and a 4.2% rate of periprosthetic-joint-infection, whereas LE had none (P = .181). FCR also had a longer length-of-stay (FCR 3.0 ± 1.3 versus LE: 1.8 ± 0.9 days, P < .001). No differences were found in 90-day readmissions (LE 7.1% versus FCR 4.2%, P = .661). CONCLUSION: All component revision may have a higher success rate than isolated LE in addressing instability but is associated with higher rates of surgical complications. With appropriate patient selection and risk-benefit discussion, isolated LE may be a reasonable surgical option for TKA instability with a lower complication profile and length-of-stay.

Extended-Release Versus Immediate-Release Triamcinolone Acetonide in Patients Who Have Knee Osteoarthritis and Type 2 Diabetes Mellitus.

BACKGROUND: Intra-articular corticosteroid injections may cause hyperglycemia (glucose level >180 mg/dL). In a phase 2 study of 33 patients who had osteoarthritis of the knee and type 2 diabetes mellitus, triamcinolone acetonide extended-release (TA-ER) was associated with minimal glycemic control disruption compared with triamcinolone acetonide immediate-release (TA-IR). This post hoc analysis characterizes the clinical relevance of these results. METHODS: Patients who had symptomatic osteoarthritis of the knee for ≥6 months, type 2 diabetes mellitus for ≥1 year, and hemoglobin A1c ≥6.5 and ≤9.0% were randomized to receive an intra-articular injection of either TA-ER or TA-IR. Changes in continuous glucose monitor daily glucose level, percentage of time in or above the target glucose range (>70 to 180 mg/dL), time to glucose level 250 mg/dL and maximum glucose level >250 mg/dL, and glycemic variability were evaluated. RESULTS: Across postinjection days 1 to 3, the TA-ER group (n = 18) had a lower median change from baseline in maximum glucose level (92.3 versus 169.1 mg/dL), a reduced percentage of time with a glucose level >250 mg/dL (12 versus 26%), a smaller proportion of patients who had a maximum glucose level >250 mg/dL (50 versus 93%), and a greater percentage of time in the target glucose range (62 versus 48%) versus the TA-IR group (n = 15). There was less glycemic variability and lower glucose spikes in the TA-ER versus TA-IR group. Median times to glucose level 250 mg/dL (44 versus 6 hours) and maximum glucose level (34 versus 13 hours) were significantly longer in the TA-ER versus TA-IR group. CONCLUSIONS: Use of TA-ER was associated with a clinically meaningful reduction in hyperglycemia versus TA-IR.

Improved Pain and Function With Triamcinolone Acetonide Extended-Release and Cryoneurolysis for Knee Osteoarthritis: Use of a New Real-World Registry.

BACKGROUND: Knee osteoarthritis (OA) affects 19% of American adults aged more than 45 years and costs $27+ billion annually. A wide range of nonoperative treatment options are available. This study compared 6 treatments: cryoneurolysis with deep genicular nerve block (Cryo-Deep/Both), cryoneurolysis with superficial nerve block (Cryo-Superficial), intra-articular hyaluronic acid (IA-HA) injections, nonsteroidal anti-inflammatory drug injections (IA-NSAIDs), IA-corticosteroids (IA-CS) injections, or IA-triamcinolone extended release (IA-TA-ER) injections over 4 months for: (1) pain severity and analgesic use; and (2) physical function (from Knee Injury and Osteoarthritis Outcome Score for Joint Replacement). METHODS: Patients who had unilateral knee OA and received nonoperative intervention were enrolled in the Innovations in Genicular Outcomes Research registry, a novel, multicenter real-world registry, between September 2021 and February 2024. A total of 480 patients were enrolled. Both pain and functional outcomes were assessed at baseline, weekly, and monthly, which were analyzed by overall trend, magnitude changes pretreatment to post-treatment, and distribution-based minimally clinically important difference (MCID) score. Multivariate linear regressions with adjustments for 7 confounding factors were used to compare follow-up outcomes among 6 treatment groups. RESULTS: Use of IA-TA-ER injections was associated with the lowest pain, greatest pain reduction, and highest prevalence of patients achieving MCID relative to other treatments (P < .001). Deep/Both-Cryo and IA-CS were associated with a higher prevalence of achieving MCID than IA-HA, IA-NSAIDs, and Cryo-Superficial (P ≤ .001). Use of IA-TA-ER was also associated with the greatest functional score, improvement from baseline, and highest prevalence of patients achieving MCID than other treatments (P ≤ .003). CONCLUSIONS: The IA-TA-ER appears to outperform other treatments in terms of pain relief and functional improvement for up to 4 months following treatment. In addition, outcomes in the novel cryoneurolysis and conventional IA-CS were similar to one another and better than those in IA-HA and IA-NSAIDs.

Cryoneurolysis Associated With Improved Pain, Function, and Sleep in Patients Following total Knee Arthroplasty: Use of a New Real-World Registry.

BACKGROUND: Total knee arthroplasty (TKA) is performed on approximately 790,000 patients annually in the United States and is projected to increase to 1.5 million by 2050. This study aimed at assessing the use of preoperative cryoneurolysis on patients undergoing TKA by analyzing: (1) pain severity; (2) opioid use; (3) functional status; and (4) sleep disturbance (SD) over 6 months following discharge. METHODS: Patients enrolled in the Innovations in Genicular Outcomes Registry between September 2021 and February 2024 were followed for 6 months. Our analyses included patients undergoing unilateral primary TKA with no preoperative opioid prescription, who either received cryoneurolysis, or did not. Baseline patient demographics were collected before TKA and tabulated. Pain management was assessed via the Brief Pain Inventory-Short Form instrument for pain severity. SD was measured using the patient-reported outcomes measurement information system questionnaire. Each outcome measure was assessed prior to TKA, weekly, and at monthly follow-up. Data were analyzed by a generalized linear mixed-effect regression model to compare cryoneurolysis versus control patients, with a P < .05 as significant. RESULTS: There were 80 patients who were treated with preoperative cryoneurolysis, while 60 control patients did not have treatment. Patients receiving cryoneurolysis experienced significantly lower pain severity and SD over the 6-month follow-up than control patients (P = .046). Cryoneurolysis was also associated with a trend toward greater functional improvement that did not reach statistical significance (P = .061). Further, patients who underwent cryoneurolysis were 72% less likely than control group patients to take opioids over 6 months following discharge (P < .001). CONCLUSIONS: Preoperative cryoneurolysis therapy in opioid-naive patients undergoing TKA is associated with improved pain, decreased opioid use, and improved SD for 6 months postoperatively. Cryoneurolysis, a nonopioid pain relief modality administered preoperatively, demonstrated substantial benefits in patients who underwent TKA.

Revision total knee arthroplasty for arthrofibrosis improves range of motion.

PURPOSE: Arthrofibrosis after primary total knee arthroplasty (TKA) is a significant contributor to patient dissatisfaction. While treatment algorithms involve early physical therapy and manipulation under anaesthesia (MUA), some patients ultimately require revision TKA. It is unclear whether revision TKA can consistently improve these patient's range of motion (ROM). The purpose of this study was to evaluate ROM when revision TKA was performed for arthrofibrosis. METHODS: A retrospective study of 42 TKA's diagnosed with arthrofibrosis from 2013 to 2019 at a single institution with a minimum 2-year follow-up was performed. The primary outcome was ROM (flexion, extension, and total arc of motion) before and after revision TKA, and secondary outcomes included patient reported outcomes information system (PROMIS) scores. Categorical data were compared using chi-squared analysis, and paired samples t tests were performed to compare ROM at three different times: pre-primary TKA, pre-revision TKA, and post-revision TKA. A multivariable linear regression analysis was performed to assess for effect modification on total ROM. RESULTS: The patient's pre-revision mean flexion was 85.6 degrees, and mean extension was 10.1 degrees. At the time of the revision, the mean age of the cohort was 64.7 years, the average body mass index (BMI) was 29.8, and 62% were female. At a mean follow-up of 4.5 years, revision TKA significantly improved terminal flexion by 18.4 degrees (p < 0.001), terminal extension by 6.8 degrees (p = 0.007), and total arc of motion by 25.2 degrees (p < 0.001). The final ROM after revision TKA was not significantly different from the patient's pre-primary TKA ROM (p = 0.759). PROMIS physical function, depression, and pain interference scores were 39 (SD = 7.72), 49 (SD = 8.39), and 62 (SD = 7.25), respectively. CONCLUSION: Revision TKA for arthrofibrosis significantly improved ROM at a mean follow-up of 4.5 years with over 25 degrees of improvement in the total arc of motion, resulting in final ROM similar to pre-primary TKA ROM. PROMIS physical function and pain scores showed moderate dysfunction, while depression scores were within normal limits. While physical therapy and MUA remain the gold standard for the early treatment of stiffness after TKA, revision TKA can improve ROM. LEVEL OF EVIDENCE: IV.

Nonsurgical Management of Osteoarthritis of the Knee: What You Should Be Injecting Now and in the Future.

Osteoarthritis of the knee affects many Americans. With the aging of the population and increasing comorbidities (eg, obesity, diabetes, hypertension, heart disease), the use of oral or topical NSAIDs is often contraindicated. Injectable treatment options are advantageous because of the ability to decrease or avoid the unwanted systematic adverse effects of NSAIDs. Injectable treatment options for osteoarthritis of the knee go back to the 1950s, beginning with corticosteroids, which remain widely used despite concerns that they may have adverse effects on articular chondrocytes and short duration of efficacy. The recent (FDA approval in 2017) introduction of a sustained-release corticosteroid (triamcinolone acetonide extended-release) offers significantly longer benefit than standard cortisone products and with substantially lower concentration levels of chondrocyte exposure to the steroid. Hyaluronic acid was added to the options for intra-articular injection in osteoarthritis of the knee in the late 1990s and remains widely used despite some controversy over its efficacy. Although guidelines for the use of hyaluronic acid for management of osteoarthritis of the knee have varied widely, careful analysis of the data and patient's perceived efficacy indicate its continued and important role in managing osteoarthritis of the knee. Finally, the past 15 years have seen an explosion in the use of biologics including platelet-rich plasma and pluripotential (often termed stem) cells. The science behind their use and efficacy is evolving and continued study is warranted.

Risk Factors for Mid-Flexion Instability After Total Knee Arthroplasty: A Systematic Review.

BACKGROUND: Mid-flexion instability after total knee arthroplasty (TKA) is a clinical entity that is not well studied and one that has been associated with patient dissatisfaction and inferior outcomes. We sought to provide a comprehensive review of risk factors associated with mid-flexion instability. METHODS: A comprehensive literature search of PUBMED, EMBASE, Google Scholar, and Cochrane Library was performed using keywords "mid flexion," "instability," and "knee arthroplasty" in all possible combinations. All studies published from 2010 to 2020 in English were considered for inclusion. Research design, question studied, and outcomes were recorded for each study. Quantitative and qualitative analysis was performed. RESULTS: Eighteen articles meeting inclusion criteria were identified and reviewed. There were 5 computational studies, 5 cadaveric studies, and 8 clinical studies. There were 14 different risk factors investigated in relation to mid-flexion instability after TKA: 6 implant-related, 6 technique-related, and 2 patient-related factors. Of these risk factors, 5 had contradictory results published to date, resulting in an inconclusive association with mid-flexion instability. The results of this review suggest that the effects of joint line elevation and radius-of-curvature of the femoral component on mid-flexion instability are inconclusive while articular surface conformity and preoperative joint laxity may play a bigger role than previously thought. CONCLUSION: Mid-flexion instability after TKA is a clinical entity distinct from other established forms of instability. There are patient-related, implant-related, and technique-related factors associated with mid-flexion instability. The majority of the evidence on this topic is derived from computational and cadaveric studies, underscoring the need for further clinical studies.

Smoking and Total Hip Arthroplasty: Increased Inpatient Complications, Costs, and Length of Stay.

BACKGROUND: Smoking is a potentially modifiable risk factor that may impact the overall outcomes of total hip arthroplasty (THA). In an era of bundled payments for THA, the purpose of this study was to evaluate, on a national level, the inpatient complications and additional costs of smokers undergoing THA. METHODS: The Nationwide Inpatient Sample was used to identify all primary elective THAs performed in the United States in 2014. This cohort was further stratified by smoking status. Inpatient hospital characteristics, costs, and complications rates were assessed. RESULTS: The Nationwide Inpatient Sample had 63,446 admissions recorded for primary THAs in 2014, corresponding to an estimated 317,230 cases nationwide. The smoking rate was 20.7%. Smokers were slightly yet significantly younger than nonsmokers (63.5 years vs 64.8 years; P < .0001). The smoking group had a significantly longer hospital stay and higher total hospital costs (both P < .0001). After using a multivariable logistic model adjusting for age, gender, and comorbidities, smokers were found to have a significantly higher odds ratio (OR [95% confidence interval {CI}]) for myocardial infarction (15.5 [5.0-47.5]), cardiac arrest (10.1 [2.2-47.6]), pneumonia (4.7 [2.4-9.1]), urinary tract infection (1.9 [1.4-2.7]), sepsis (13.1 [3.5-49.0]), acute renal failure (2.9 [2.2-3.7]), discharge to a skilled nursing facility (1.3 [1.2-1.4]), and mortality (11.7 [2.0-70.5]). CONCLUSIONS: Smoking remains a highly prevalent and important risk factor for complications in elective primary THA in the United States. Patients who smoke have a significantly higher rate of complications and generate significantly higher postoperative inpatient costs. These findings are important for risk stratification, bundled payment considerations, as well as perioperative patient education and intervention.

Balancing Thromboprophylaxis and Bleeding in Total Joint Arthroplasty: Impact of Eliminating Enoxaparin and Predonation and Implementing Pneumatic Compression and Tranexamic Acid.

BACKGROUND: Venous thromboembolic disease (VTED) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) poses substantial risk. Pharmacologic prophylaxis against VTED can cause bleeding, transfusion, and associated complications. The ActiveCare+SFT is a portable, intermittent pneumatic compression device (IPCD), providing equivalent VTED prophylaxis to pharmacologic agents without associated bleeding. Tranexamic acid (TXA) is an antifibrinolytic that reduces blood loss after THA and TKA. Our objective was to measure blood transfusion and VTED after eliminating enoxaparin, introducing an IPCD, eliminating autologous blood transfusion, and administering TXA during primary TKA and THA. METHODS: Four consecutive cohorts of THA and TKA patients were studied. Group A, the historical control, received enoxaparin VTED prophylaxis. Group B received IPCD VTED prophylaxis. Group C received IPCD VTED prophylaxis along with TXA (1 g intravenous at incision and closure). Groups A, B, and C predonated 1 unit of autologous blood. Group D received IPCD VTED prophylaxis, TXA as above, but did not donate blood preoperatively. RESULTS: Seventeen of 50 patients (34%) in Group A, 7 of 47 (14.9%) patients in Group B, 4 of 43 (9.3%) patients in Group C, and 0 of 46 patients in Group D received transfusions. There were no major symptomatic VTED events. CONCLUSION: Using an IPCD and TXA and discontinuing enoxaparin and preoperative autologous blood donation eliminated blood transfusion in primary THA and TKA without any increase in VTED. Using an IPCD instead of enoxaparin, adding TXA, and eliminating preoperative autologous donation each had an incremental dose response effect. This protocol provides effective VTED prophylaxis equivalent to pharmacologic methods and eliminates transfusion risk in the primary THA and TKA population.

No conclusive evidence that histologically found granulomas and acute local reactions following hylan G-F 20 injections are related or have clinical significance.

Osteoarthritic (OA) knee pain can be successfully treated with hylan G-F 20 (Synvisc, Sanofi Biosurgery, Cambridge, MA) with few local adverse events. However, a few studies have identified hyaluronate positive (HA+) granulomas in the synovial tissue of patients treated with hylan G-F 20 raising the question of their relationship and clinical significance. To understand the potential relationship of HA+ granulomas with the occurrence of acute local reactions (ALRs), we evaluated the synovial tissue of OA patients undergoing total knee replacement that had previously been treated with hylan G-F 20 (n = 101) or had not been treated (n = 20). Granulomas were observed in nine patients, of which eight were in the hylan G-F 20 group (7.9%); HA+ granulomas were identified in six of these eight patients (5.9%). Three of the six patients with HA+ granulomas experienced an ALR within 30 days of administering an injection. Overall, we found no consistent relationship between histologically found HA+ granulomas and the occurrence of an ALR following hylan G-F 20 treatment. These microscopic granulomas were not associated with any symptoms and likely have little clinical significance. The low occurrence of granulomas and/or ALRs should not preclude use of hylan G-F 20 for the treatment of knee pain associated with OA.

Knee osteoarthritis: disease burden, available treatments, and emerging options.

Osteoarthritis (OA) is a prevalent condition that affects nearly 528 million people worldwide, including 23% of the global population aged ⩾40, and is characterized by progressive damage to articular cartilage, which often leads to substantial pain, stiffness, and reduced mobility for affected patients. Pain related to OA is a barrier to maintaining physical activity and a leading cause of disability, accounting for 2.4% of all years lived with disability globally, reducing the ability to work in 66% of US patients with OA and increasing absenteeism in 21% of US patients with OA. The joint most commonly involved in OA is the knee, which is affected in about 60%-85% of all OA cases. The aging population and longer life expectancy, coupled with earlier and younger diagnoses, translate into a growing cohort of symptomatic patients in need of alternatives to surgery. Despite the large number of patients with knee OA (OAK) worldwide, the high degree of variability in patient presentation can lead to challenges in diagnosis and treatment. Multiple society guidelines recommend therapies for OAK, but departures from guidelines by healthcare professionals in clinical settings reflect a discordance between evidence-based treatment algorithms and routine clinical practice. Furthermore, disease-modifying pharmacotherapies are limited, and treatment for OAK often focuses solely on symptom relief, rather than underlying causes. In this narrative review, we summarize the patient journey, analyze current disease burden and nonsurgical therapy recommendations for OAK, and highlight emerging and promising therapies-such as cryoneurolysis, long-acting corticosteroids, and gene therapies-for this debilitating condition.

No Decrease in Early Survivorship of Dual Mobility Implants in Primary Total Hip Arthroplasty.

Background: Dual mobility (DM) implants in primary total hip arthroplasty (THA) have gained recent popularity; however, safety concerns persist. The purpose of this study was twofold: 1) assess trends in DM implant adoption; and 2) evaluate the impact of modular DM implants on dislocation and all-cause revision rates at short-term follow-up. Methods: This retrospective study identified patients in our institutional arthroplasty database who underwent primary posterior approach THA for degenerative conditions from November 2013 to December 2020. Patients undergoing primary THA for fracture were excluded. Patients were divided into two cohorts: modular DM and non-DM implants. Annual DM utilization and dislocation rates were recorded. Patient records were reviewed to determine implant selection and identify indications for dislocations and reoperations. Results: Institutional adoption was rapid, increasing from 3.4% in 2013 to 47.1% in 2020. Of the 4548 primary THA cases from 2013 to 2020, 2859 (62.9%) had minimum one-year follow-up data for inclusion. There were 724 (25.3%) with DM implants and 2135 (74.7%) with non-DM implants. The DM group had a significantly lower dislocation rate (0.14% vs 0.84%, P = .04), with similar all-cause revision rates (2.49% vs 2.72%, P = .74) at one-year follow-up. No cases of DM-specific complications (metallosis or intraprosthetic dislocations) were noted. Conclusions: From 2013 to 2020, DM implant utilization in primary THA steadily increased. Use of modular DM implants is associated with a decreased dislocation rate without compromised survivorship at one-year follow-up when compared to non-DM implants. No instances of modular DM-specific complications were identified; however, longer-term surveillance is necessary to verify these findings. Level of Evidence: Prognostic Level III.

Robotic-assisted total knee arthroplasty reduces soft-tissue releases which improves functional outcomes: A retrospective study.

BACKGROUND: There is increasing use of Robotic-Assisted (RA) and personalized alignment techniques in total knee arthroplasty (TKA). The hypothesis of this study was that RA TKA would result in fewer soft-tissue releases, and that fewer soft-tissue releases would be associated with improved clinical outcomes. METHODS: A retrospective review of an internal company registry was conducted for all primary TKAs performed from Jan 1, 2014, through a database extract date of Nov 4, 2022. These were grouped by whether there was an intentional soft-tissue release performed (STR) during the surgery or not (NSTR) and whether RA was utilized. The incidence of STR was compared between RA-TKAs and those performed with manual instrumentation. Knee Society Score (KSS) and Knee Society Function Scores (KSFS) were collected at 6 months, 1 year and 2 years. Kaplan-Meier survivorship was performed. RESULTS: The incidence of STR was significantly lower for RA vs. Manual (43.81% Vs 86.62%, p < 0.0001). The TKAs with NSTR had higher KSFS compared to those with STR at 6 months (84.73 Vs. 77.51, p < 0.0001), 1 year (89.87 Vs. 83.54, p < 0.0001) and 2 years (90.09 Vs. 82.65, p < 0.0001). There was no difference in survivorship, or KSS at any time point. However, the NSTR group had improved KSS pain sub score at 2 years. CONCLUSION: The results of this observational, retrospective analysis found that the incidence of soft-tissue release was lower with RA-TKA. Further, regardless of if RA was used, avoiding releases was associated with improved KSFS and KSS pain scores through 2 years post-operatively.

Preoperative Depression Is Associated With Increased Short-term Complications But Equivalent Long-term Outcomes in Total Knee Arthroplasty.

Concomitant depression negatively impacts outcomes following total knee arthroplasty (TKA). Patient-Reported Outcomes Measurement Information System (PROMIS) surveys are validated measures that quantify depression, pain, and physical function. We hypothesized that higher preoperative PROMIS-depression scores would be associated with inferior outcomes following TKA. A total of 258 patients underwent primary TKA at a tertiary academic center between June 2018 and August 2020. PROMIS scores were collected preoperatively and at 6 weeks, 3 months, 1 year, and 2 years postoperatively. Patients with preoperative PROMIS depression scores of 55 or greater were considered PROMIS depressed (PD) and patients with scores less than 55 were considered not PROMIS depressed (ND). The primary outcomes were changes in PROMIS scores. Secondary outcomes included total and daily mean morphine milligram equivalents (MME) received during admission as well as 90-day hospital readmission and 2-year all-cause revision rates. There were 66 (25.58%) patients in the PD group and 192 (74.42%) in the ND group. Patients in the PD group had improved depression scores at all follow-up intervals (P<.001) and decreased pain scores at 1 year (P=.016). Both groups experienced similar changes in function scores at each follow-up interval. Patients in the PD group had higher total (P=.176) and daily (P=.433) mean MME use while admitted. Ninety-day hospital readmissions were higher in the PD group (P=.002). There were no differences in 2-year revision rates (P=.648). Preoperative PROMIS-depression scores of 55 or greater do not negatively impact postoperative function, depression, or pain, and patients with these scores have greater improvement in depression and pain at certain intervals. Patients in the PD group had higher readmission rates. [Orthopedics. 2024;47(1):40-45.].

Intra-Articular Corticosteroid Injections Into a Preexisting Total Knee Arthroplasty are Associated With Increased Risk of Periprosthetic Joint Infection and Revision.

Background: This study aims to determine the risks of periprosthetic joint infection (PJI) and revision associated with injecting a preexisting total knee arthroplasty (TKA) with intra-articular corticosteroids (IACSs). Methods: The PearlDiver database was used to identify patients who underwent elective, primary TKA between 2015 and 2019. Patients who received IACS injections into the ipsilateral knee within 1 year after their primary TKA were matched 2:1 on age, gender, and Charlson comorbidity index and compared to a no-injection control group. The incidence of PJI at 1 year postoperatively and revision at 2 years postoperatively were compared between groups. Results: A total of 27,059 patients were in the injection cohort and 54,116 patients in the control cohort. The overall PJI rate was 1.3% in the injection cohort and 0.8% in the control cohort (P < .001). The rate of PJI increased with the number of post-TKA IACS injections received: 1 injection (1.3%), 2 injections (1.4%), and >3 injections (1.8%) (P < .001 for all, compared to controls). The revision rate was 3.1% in the injection cohort and 1.3% in the control cohort (P < .001). Revision rates increased with the number of post-TKA IACS injections received: 1 injection (2.5%), 2 injections (4.2%), and >3 injections (7.3%) (P < .001 for all, compared to controls). Conclusions: IACS injections into a preexisting TKA are associated with an incremental increased risk of prosthetic joint infection and revision. Considering the potential deleterious impact of PJI and complexity of revision procedures, IACS injections into a preexisting TKA should be strongly discouraged.

Increased Prevalence, Complications, and Costs of Smokers Undergoing Total Knee Arthroplasty.

Given a national push toward bundled payment models, the purpose of this study was to examine the prevalence as well as the effect of smoking on early inpatient complications and cost following elective total knee arthroplasty (TKA) in the United States across multiple years. Using the nationwide inpatient sample, all primary elective TKA admissions were identified from 2012 to 2014. Patients were stratified by smoking status through a secondary diagnosis of "tobacco use disorder." Patient characteristics as well as prevalence, costs, and incidence of complications were compared. There was a significant increase in the rate of smoking in TKA from 17.9% in 2012 to 19.2% in 2014 (p < 0.0001). The highest rate was seen in patients < 45 years of age (27.3%). Hospital resource usage was significantly higher for smokers, with a length of stay of 3.3 versus 2.9 days (p < 0.0001), and hospital costs of $16,752 versus $15,653 (p < 0.0001). A multivariable logistic model adjusting for age, gender, and comorbidities showed that smokers had an increased odds ratio for myocardial infarction (5.72), cardiac arrest (4.59), stroke (4.42), inpatient mortality (4.21), pneumonia (4.01), acute renal failure (2.95), deep vein thrombosis (2.74), urinary tract infection (2.43), transfusion (1.38) and sepsis (0.65) (all p < 0.0001). Smoking is common among patients undergoing elective TKA, and its prevalence continues to rise. Smoking is associated with higher hospital costs as well as higher rates of immediate inpatient complications. These findings are critical for risk stratification, improving of bundled payment models as well as patient education, and optimization prior to surgery to reduce costs and complications.

Socioeconomic factors affecting outcomes in total knee and hip arthroplasty: a systematic review on healthcare disparities.

BACKGROUND: Recent studies showed that healthcare disparities exist in use of and outcomes after total joint arthroplasty (TJA). This systematic review was designed to evaluate the currently available evidence regarding the effect socioeconomic factors, like income, insurance type, hospital volume, and geographic location, have on utilization of and outcomes after lower extremity arthroplasty. METHODS: A comprehensive search of the literature was performed by querying the MEDLINE database using keywords such as, but not limited to, "disparities", "arthroplasty", "income", "insurance", "outcomes", and "hospital volume" in all possible combinations. Any study written in English and consisting of level of evidence I-IV published over the last 20 years was considered for inclusion. Quantitative and qualitative analyses were performed on the data. RESULTS: A total of 44 studies that met inclusion and quality criteria were included for analysis. Hospital volume is inversely correlated with complication rate after TJA. Insurance type may not be a surrogate for socioeconomic status and, instead, represent an independent prognosticator for outcomes after TJA. Patients in the lower-income brackets may have poorer access to TJA and higher readmission risk but have equivalent outcomes after TJA compared to patients in higher income brackets. Rural patients have higher utilization of TJA compared to urban patients. CONCLUSION: This systematic review shows that insurance type, socioeconomic status, hospital volume, and geographic location can have significant impact on patients' access to, utilization of, and outcomes after TJA. LEVEL OF EVIDENCE: IV.

Race, Utilization, and Outcomes in Total Hip and Knee Arthroplasty: A Systematic Review on Health-Care Disparities.

BACKGROUND: Previous studies have shown that utilization and outcomes of total joint arthroplasty (TJA) are not equivalent across different patient cohorts. This systematic review was designed to evaluate the currently available evidence regarding the effect that patient race has, if any, on utilization and outcomes of lower-extremity arthroplasty in the United States. METHODS: A literature search of the MEDLINE database was performed using keywords such as "disparities," "arthroplasty," "race," "joint replacement," "hip," "knee," "inequities," "inequalities," "health," and "outcomes" in all possible combinations. All English-language studies with a level of evidence of I through IV published over the last 20 years were considered for inclusion. Quantitative and qualitative analyses were performed on the collected data. RESULTS: A total of 82 articles were included. There was a significantly lower utilization rate of lower-extremity TJA among Black, Hispanic, and Asian patients compared with White patients (p < 0.05). Black and Hispanic patients had lower expectations regarding postoperative outcomes and their ability to participate in various activities after surgery, and they were less likely than White patients to be familiar with the arthroplasty procedure prior to presentation to the orthopaedic surgeon (p < 0.05). Black patients had increased risks of major complications, readmissions, revisions, and discharge to institutional care after TJA compared with White patients (p < 0.05). Hispanic patients had increased risks of complications (p < 0.05) and readmissions (p < 0.0001) after TJA compared with White patients. Black and Hispanic patients reached arthroplasty with poorer preoperative functional status, and all minority patients were more likely to undergo TJA at low-quality, low-volume hospitals compared with White patients (p < 0.05). CONCLUSIONS: This systematic review shows that lower-extremity arthroplasty utilization differs by racial/ethnic group, and that some of these differences may be partly explained by patient expectations, preferences, and cultural differences. This study also shows that outcomes after lower-extremity arthroplasty differ vastly by racial/ethnic group, and that some of these differences may be driven by differences in preoperative functional status and unequal access to care. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Improved Treatment Effect of Triamcinolone Acetonide Extended-Release in Patients with Concordant Baseline Pain Scores on the Average Daily Pain and Western Ontario and McMaster Universities Osteoarthritis Index Pain Scales.

INTRODUCTION: A phase 3 randomized controlled study comparing triamcinolone acetonide extended-release (TA-ER) to conventional TA crystalline suspension (TAcs) reported variable efficacy results. Enrollment criteria may have contributed to this discrepancy, as moderate-to-severe average daily pain (ADP) was required at baseline, whereas no limitations were placed on Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC-A) pain severity. We conducted a post hoc sensitivity analysis to compare treatment effects in patients reporting moderate-to-severe osteoarthritis (OA) pain on both scales. METHODS: Participants > 40 years old with symptomatic knee OA were randomly assigned to a single intra-articular injection of TA-ER 32 mg, TAcs 40 mg, or saline-placebo and followed for 24 weeks. Patient-reported ADP, WOMAC-A, rescue medication usage, and adverse events (AEs) were assessed. Participants who reported moderate-to-severe OA pain at baseline using both instruments (ADP ≥ 5 to ≤ 9, maximum 10 and WOMAC-A ≥ 2, maximum 4) were categorized as "concordant" pain reporters; patients with baseline moderate-to-severe OA on ADP only were termed "discordant" pain reporters. RESULTS: Two-hundred-ninety-two concordant pain reporters of 484 total subjects received TA-ER 32 mg (n = 95), TAcs 40 mg (n = 100), or saline-placebo (n = 97). Baseline characteristics and AE profiles of the concordant and discordant pain responders were consistent with the full analysis population. Among concordant pain reporters, TA-ER significantly (p < 0.05) improved ADP scores vs. TAcs (weeks 5-19; area-under-the-effect [AUE]weeks1-12; AUEweeks1-24) and saline-placebo (weeks 1-20; AUEweeks1-12; AUEweeks1-24). At week 12, a higher proportion reported no knee pain (ADP = 0) with TA-ER (~ 28%) vs. TAcs (~ 8%). TA-ER significantly improved WOMAC-A vs. TAcs at weeks 4, 8, and 12, with significant reduction in rescue medication usage observed with TA-ER from weeks 2 to 20 vs. TAcs. CONCLUSIONS: In patients reporting moderate-to-severe knee OA pain at baseline based on concordant ADP and WOMAC-A scores, TA-ER provided statistically significant pain relief for ≥ 12 weeks compared with conventional TAcs. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02357459.

Osteoarthritis is a chronic condition that greatly impacts patients. Pain is the most common symptom of osteoarthritis. Clinical trials evaluating the effects of new drugs to treat osteoarthritis pain frequently use scales to rate overall pain following treatment. Patients may rate their pain using a number that best describes their pain, with the lowest number typically meaning "no pain," and the highest number typically meaning "pain as bad as you can imagine." Other rating scales may be used to rate pain in situations commonly associated with osteoarthritis.Results from a large clinical trial demonstrated that injection of an extended-release steroid significantly reduced pain compared with a conventional steroid injection on only one of the two pain-reporting scales used in the trial. A closer look found that some patients reported their pain differently on the two rating scales at the start of the trial, with some reporting moderate-to-severe pain using one questionnaire and mild pain using the other. Here, we focused on those patients who reported having moderate-to-severe osteoarthritis knee pain on both pain scales at the start and found that the pain relief benefit associated with the extended-release steroid injection was greatly improved compared with the conventional steroid injection with both measures. Patients receiving the extended-release steroid injection also decreased their use of rescue medication for pain relief.