Transfusion Rates in Total Hip Arthroplasty Are lower in Patients with Direct Anterior Approach.

BACKGROUND: Blood conservation and reduction in the need for allogeneic blood transfusion (ABT) has been a subject of importance in total hip arthroplasty. There are a number of well-recognized parameters that influence blood loss during total hip arthroplasty (THA). The role of surgical approach on blood loss and the rate of ABT during THA is not well studied. The hypothesis of this study was that blood loss and the need for ABT is lower with direct anterior (DA) approach. METHODS: In a case-control retrospective cohort study, we analyzed 1,524 primary THAs performed at a single institution by seven fellowship-trained surgeons between January 2015 to March 2017. All patients received THA using either the modified direct lateral (DL) or direct anterior (DA) approach using a standard operating table. The overall ABT rate was 10.2% (155/1,524) in the cohort. Demographic, surgical, and postoperative data were extracted and analyzed. Logistic regression was used to identify independent risk factors for transfusion. RESULTS: Higher preoperative hemoglobin (p<0.001), use of DA approach (p<0.016) and administration of tranexamic acid TXA, (p=0.024) were identified as independent factors which reduced the odds of ABT. Operative time (p<0.001) was associated with an increased odd of ABT, while age, BMI and type of anesthesia were not statistically significant. CONCLUSION: Based on the findings of this study, direct anterior approach for THA appears to be protective against blood loss and reduced ABT rate, when controlling for confounding variables.

Tranexamic Acid Reduces the Rate of Periprosthetic Joint Infection After Aseptic Revision Arthroplasty.

BACKGROUND: Revision total joint arthroplasty (TJA) has a higher rate of periprosthetic joint infection (PJI) compared with primary TJA, possibly as the result of increased allogeneic blood transfusion. Tranexamic acid (TXA) is gaining popularity in revision TJA to minimize blood loss and the need for transfusion; however, its effect on PJI reduction has yet to be investigated. The hypothesis of this study was that the administration of TXA during revision arthroplasty is protective against subsequent PJI. METHODS: A prospectively maintained institutional database was used to identify patients who underwent revision TJA for aseptic failure from 2009 to 2018 and had a minimum follow-up of 90 days. Patients who developed PJI following revision arthroplasty were identified. All patients with PJI met Musculoskeletal Infection Society (MSIS) criteria. A multivariate analysis was performed to identify variables independently associated with PJI after aseptic revision TJA. RESULTS: Overall, 1,731 patients who underwent aseptic revision were identified; of these patients, 83 (4.8%) developed PJI. Patients who received TXA had significantly lower rates (p = 0.029) of PJI postoperatively at 3.30% compared with those who did not receive TXA at 5.73%. After controlling for relevant confounding variables, TXA remained a significant independent factor that protected against PJI (odds ratio [OR], 0.47 [95% confidence interval (CI), 0.23 to 0.90]; p = 0.030). Female sex was also identified as a significant independent factor that protected against PJI (OR, 0.52 [95% CI, 0.30 to 0.88]; p = 0.016). However, preoperative anemia was independently associated with an increased risk of subsequent PJI (OR, 2.37 [95% CI, 1.34 to 4.16]; p = 0.003). CONCLUSIONS: Based on this study conducted at a single institution, the use of TXA during aseptic revision arthroplasty was independently associated with a reduced risk of subsequent acute PJI after adjusting for multiple patient characteristics and surgical factors. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Current Evidence-based Indications for Modern Noncemented Total Knee Arthroplasty.

Total knee arthroplasty (TKA) is one of the most common procedures performed in orthopaedic surgery. Traditionally, most TKAs have been performed by cementing the implant to the bone with polymethyl methacrylate to provide fixation. Noncemented implants that rely on boney ingrowth for fixation are increasingly appealing to surgeons, given success in total hip arthroplasty and the desire for long-term stability of implants in younger patients. Despite high failure rates with early designs, several series of recent designs have demonstrated improved survivorship, although this has not been confirmed in larger registry studies. Modern screwless designs with improved porous coating are thought to contribute to better ingrowth and have been designed to address previous implant pitfalls. Surgeons must be aware of the potential advantages and limitations of noncemented TKA.

Tranexamic Acid Is Associated With Reduced Periprosthetic Joint Infection After Primary Total Joint Arthroplasty.

BACKGROUND: Previous studies have demonstrated preoperative anemia to be a strong risk factor for periprosthetic joint infection (PJI) in total joint arthroplasty (TJA). Allogeneic blood transfusion can be associated with increased risk of PJI after primary and revision TJA. Tranexamic acid (TXA) is known to reduce blood loss and the need for allogeneic blood transfusion after TJA. The hypothesis of this study is that administration of intravenous TXA would result in a reduction in PJI after TJA. METHODS: An institutional database was utilized to identify 6340 patients undergoing primary TJA between January 1, 2013 and June 31, 2017 with a minimum of 1-year follow-up. Patients were divided into 2 groups based on whether they received intravenous TXA prior to TJA or not. Patients who developed PJI were identified. All PJI patients met the 2018 International Consensus Meeting definition for PJI. A multivariate regression analysis was performed to identify variables independently associated with PJI. RESULTS: Of the patients included, 3683 (58.1%) received TXA and 2657 (41.9%) did not. The overall incidence of preoperative anemia was 16%, postoperative blood transfusion 1.8%, and PJI 2.4%. Bivariate analysis showed that patients who received TXA were significantly at lower odds of infection. After adjusting for all confounding variables, multivariate regression analysis showed that TXA is associated with reduced PJI after primary TJA. CONCLUSION: TXA can help reduce the rate of PJI after primary TJA. This protective effect is likely interlinked to reduction in blood loss, lower need for allogeneic blood transfusion, and issues related to immunomodulation associated with blood transfusion.

Highlighting the Roles of Anemia and Aspirin in Predicting Ninety-Day Readmission Following Aseptic Revision Total Joint Arthroplasty.

BACKGROUND: Revision total joint arthroplasties (TJAs) are associated with an increased rate of complications. To date, it is unclear what drives readmission after aseptic revision arthroplasty and what measures can be taken to possibly avoid them. The purpose of this study is to (1) determine the reasons for readmission after aseptic revision TJA and (2) identify patient-specific or postoperative risk factors through a multivariate analysis. METHODS: A retrospective study examined 1503 cases of aseptic revision TJA between 2009 and 2016 at an urban tertiary care hospital. Eighty-seven cases (5.8%) of readmission within 90 days of index surgery were identified. Bivariate and multivariate analyses were performed to assess independent risk factors for readmission. RESULTS: The reasons for readmission were infection (38%), wound complications (22%), and dislocation/instability of the prosthetic joint (13%). Only preoperative anemia was associated with an increased odds ratio (OR) of readmission (OR 1.82, 95% confidence interval [CI] 1.126-2.970, P = .015), whereas postoperative venous thromboembolism prophylaxis with aspirin (OR 0.58, 90% CI 0.340-0.974, P = .039) and discharge to an inpatient rehab facility (OR 0.22, 95% CI 0.051-0.950, P = .042) were associated with significantly lower odds of readmission. CONCLUSION: Based on this single institutional study, addressing preoperative anemia and considering the implementation of aspirin for venous thromboembolism prophylaxis may be 2 targets to potentially reduce readmission after aseptic revision TJA.

Positive Blood Cultures Decrease the Treatment Success in Acute Hematogenous Periprosthetic Joint Infection Treated With Debridement, Antibiotics, and Implant Retention.

BACKGROUND: The influence of positive blood cultures on surgical outcome of acute hematogenous periprosthetic joint infection (PJI) treated by debridement, antibiotics, and implant retention (DAIR) remains unknown. This study evaluated the influence of positive blood cultures on the treatment success of DAIR in patients with acute hematogenous PJI. METHODS: A retrospective chart review on 49 patients with blood culture data for acute hematogenous PJI was performed from 2005 to 2016 at a single institution. All patients were treated by DAIR and had a minimum follow-up of 1 year. Treatment success was defined by the Delphi criteria. Multivariate logistic regression analysis was performed to identify variables associated with positive blood culture and treatment success. Kaplan-Meier survivorship curves and log-rank tests were used for analysis. RESULTS: Overall, 44.9% (22/49) of blood cultures obtained yielded positive growth. Elevated Elixhauser comorbidity index was a significant risk factor associated with positive blood (adjusted odds ratio [OR], 1.65; 95% confidence interval [CI], 1.13-2.40; P = .049). A positive blood culture was the only significant factor predicting treatment failure in acute hematogenous PJI (OR, 3.94; 95% CI, 1.18-13.1; P = .026) after adjusting for confounding variables. Kaplan-Meier survivorship for infection-free implant survivorship was 53.1% (95% CI, 38.3%-65.8%) at 1 year for all patients, 66.7% (95% CI, 45.7%-81.1%) for patients with negative blood cultures, and 36.4% (95% CI, 17.2%-55.7%) for patients with positive blood cultures (P = .037). CONCLUSION: The presence of positive blood cultures is associated with decreased treatment success of DAIR for acute hematogenous PJI. Patients with more comorbidities may need to be treated more aggressively for a favorable outcome.

The Significance of Osteoarthritis-associated Bone Marrow Lesions in the Knee.

Bone marrow lesions of the knee in patients with osteoarthritis (OA-BML) are an important clinical entity that may explain progressive pain, decreased quality of life, and impaired function. MRI of OA-BMLs demonstrates a region of subchondral bone with hyperintense marrow signal on T2-weighted images. Histopathology retrieval studies have demonstrated that these lesions correlate with microdamage of the trabecular bone, and subsequently, this leads to a vicious cycle of subchondral bone attrition, attempts at repair, pain, and progressive deformity. These lesions have also been linked to accelerated loss of adjacent articular cartilage and increases in the severity of knee pain, prompting patients to seek musculoskeletal care and treatment. Multiple studies have also correlated the presence of an OA-BML with an increased probability of seeking knee arthroplasty. Knowledge of these lesions is important in the context that knee OA is both a cartilage-based and bone-based disease. Further study of OA-BMLs may provide opportunities for early intervention and OA disease-modifying treatments.

Preoperative Hemoglobin Predicts Postoperative Transfusion Despite Antifibrinolytics During Total Knee Arthroplasty.

Current antifibrinolytics have decreased perioperative blood loss; however, some patients still require transfusions postoperatively. The authors sought to determine the risk factors associated with postoperative transfusions and to establish a "cutoff" preoperative hemoglobin threshold value specific to total knee arthroplasty (TKA) that would identify patients who would benefit from blood conservation programs. The institutional database was queried for primary TKA patients. Preoperative patient demographics and hemoglobin values were determined in addition to intraoperative and postoperative variables, including transfusion rate. Patients were stratified by whether they received a transfusion perioperatively, and risk factors were identified through univariable and multivariable analysis. Optimal cutoff values for hemoglobin were identified by concurrently maximizing the sensitivity and specificity for predicting the risk of a postoperative transfusion event. Men and women were analyzed independently. A total of 532 primary TKAs were included for analysis, and 33 patients (6.2%) required a transfusion. Advanced age (P=.019), low pre-operative hemoglobin value (P<.001), and failure to receive tranexamic acid (P<.001) were associated with increased risk of postoperative transfusion. A preoperative hemoglobin value of 12.5 g/dL was identified as the optimal cutoff for predicting postoperative transfusion requirements across all patients, with a sensitivity of 84.8% and a specificity of 76.4%. Preoperative anemia remains predictive of transfusion following TKA despite current antifibrinolytics. Patients with a preoperative hemoglobin value of less than 12.5 g/dL who are not receiving intravenous tranexamic acid are particularly at risk and should be considered for blood conservation programs. [Orthopedics. 2019; 42(2):103-109.].

Continuous adductor canal blockade facilitates increased home discharge and decreased opioid consumption after total knee arthroplasty.

BACKGROUND: There is a growing interest in avoiding discharging patients to rehab to maximize outcome and minimize complications after total knee arthroplasty (TKA). In addition, use of postoperative pain pathways that minimize opioid use is critical amidst the current opioid epidemic. However, the ideal pain regimen after TKA has yet to be determined. METHODS: From July 1, 2013 to October 1, 2014 two perioperative pathways were used to address surgical pain. These included either a single shot femoral nerve block plus liposomal bupivacaine pericapsular injection (FNB + LB-PAI) or adductor canal catheter plus posterior capsule single shot block (ACC + iPACK), each with an oral analgesic protocol. Little modification occurred with regard to surgical technique, postoperative medications, or postoperative physical therapy (PT). RESULTS: Overall, 264 unilateral, primary TKA patients (146 FNB + LB-PAI, 118 ACC + iPACK) were included. ACC + iPACK patients had a shorter median length of stay (LOS, 2.0 vs 3.0, p < 0.001), more discharges home (79.7% vs 67.8%, p = 0.002), and less median opioid consumption (IV morphine equivalents, IVME, 20.0 vs 44.1, p < 0.001) than the FNB + LB-PAI group. In multivariable analysis, use of ACC + iPACK remained independently associated with shorter LOS, increased discharge home, and less IVME consumed when controlling for confounding variables. ACC + iPACK patients also had fewer opioid related adverse events (0.8 vs 5.5, p = 0.045) and a lower rate of MUA (0.8% vs 6.2%, p = 0.026). CONCLUSIONS: We recommend ACC + iPACK with a multimodal oral analgesic protocol as the primary postoperative analgesia in enhanced recovery TKA protocols. This resulted in an easier recovery with fewer complications. LEVEL OF EVIDENCE: Level III.

Robotic-assisted Medial Unicompartmental Knee Arthroplasty: Options and Outcomes.

Medial unicompartmental knee arthroplasty (UKA) has several benefits over total knee arthroplasty for the surgical treatment of isolated medial compartmental arthritis in the knee, including reduced surgical risk and postoperative morbidity, rapid recovery, more normal kinematics, greater patient satisfaction, and shorter hospitalization. Nonetheless, there is substantial concern about the higher revision rates and lower survivorship in UKA compared to those in total knee arthroplasty. Robotic assistance has been advanced to improve the precision of bone preparation, component alignment, and quantified ligament balance in UKA, with the ultimate goal of improving kinematics and implant survivorship. Two currently available semiautonomous robotic platforms have demonstrated improved accuracy, and emerging short-term follow-up has demonstrated satisfactory functional outcomes. Further studies will be needed to determine if these technologies indeed have a meaningful impact on patient outcomes and survivorship in the mid- to long term.

Web-Based, Self-Directed Physical Therapy After Total Hip Arthroplasty Is Safe and Effective for Most, but Not All, Patients.

BACKGROUND: Recent data suggested that unsupervised, self-directed physical therapy (SDPT) is both safe and efficacious for patients undergoing total hip arthroplasty (THA) and that formal outpatient physical therapy (OPPT) may not be routinely required. The purpose of this study was to evaluate the routine use of an SDPT program in a nonselect patient population. METHODS: This is a multi-surgeon, single-institution, retrospective study of 941 consecutive patients discharged home, from January 2016 to December 2016, after primary, unilateral THA and enrolled in a web-based SDPT program. Patients were seen 4 weeks after surgery and OPPT was prescribed for perceived need, patient request, or if unable to use the web-based program. Patient-reported outcomes, medical comorbidities, and assessment of home environment were prospectively recorded. RESULTS: Overall, 646 of 941 patients (68.7%) were not prescribed OPPT (SDPT-only group) while 295 of 941 patients (31.3%) were prescribed OPPT (SDPT + OPPT group). In the SDPT + OPPT group, 88.2% were for perceived need, 10.8% for patient request, and 1.0% due to inability to use the web-based platform. Multivariate analysis identified male sex (odds ratio, 0.64; 0.45-0.90; P = .012) and a higher preoperative Short Form-12 physical component (odds ratio, 0.98; 0.96-0.99; P = .036) as independent variables protective against requiring OPPT. At a minimum 6-month follow-up, the SDPT-only group had statistically higher hip disability and osteoarthritis outcome score junior compared to the SDPT + OPPT cohort (85.0 vs 80.9; P = .012). CONCLUSION: Web-based SDPT is safe and effective for most, but not all, patients eligible for home discharge after THA. It is critical to preserve OPPT services for the one-third of patients who require them. LEVEL OF EVIDENCE: Level III.