Prior Anterior Cruciate Ligament Reconstruction Does Not Compromise the Functional Outcomes of Medial Unicompartmental Knee Arthroplasty Although Revision for Progressive Arthritis May Occur Earlier.

BACKGROUND: Anterior cruciate ligament (ACL) deficiency is commonly considered a contraindication for unicompartmental knee arthroplasty (UKA). The purpose of this study is to compare the outcomes of UKA after prior ACL reconstruction (rACL cohort) to UKA with an intact native ACL (nACL cohort). METHODS: Forty-five patients from 3 institutions who underwent medial UKA after prior rACL were matched by age, gender, preoperative function scores, and body mass index to 90 patients who underwent UKA with an intact nACL. Primary outcomes were Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Oxford Knee Scores, Knee Society Functional Scores, and Kellgren-Lawrence scores in the unresurfaced, lateral tibiofemoral compartment. Secondary outcomes were postoperative complications and the need for revision to TKA. RESULTS: At a mean of 3.6 years, all PROMs improved significantly with no differences identified between groups. The incidence of revision TKA was similar between cohorts (P = 1.00); however, the mean time to revision for progressive osteoarthritis was 4.0 years in the nACL group and 2.2 years in the rACL group. Twenty percent of rACL patients had a postoperative complication compared to 8% in the nACL group. Despite presenting with a similar degree of lateral arthritis, a greater percentage of patients developed Kellgren-Lawrence scores of ≥3 in the rACL cohort (9%) than in the nACL cohort (0%). CONCLUSION: A previously reconstructed ACL does not appear to compromise the short-term functional outcomes of UKA; however, there is a higher rate of minor complications and progression of lateral compartment arthritis, which should be considered with patients in the shared decision process.

Partial Knee Arthroplasty: The State of the Art.

Unicompartmental knee arthroplasty and patellofemoral arthroplasty were pioneered in the 1970s but abandoned by most in favor of total knee arthroplasty because of inconsistent early outcomes. Advancements in implant design, instrumentation, indications, and surgical techniques have enhanced results and led to a resurgence in both unicompartmental knee arthroplasty and patellofemoral arthroplasty for appropriate candidates. In appropriately selected patients, current implants and techniques provide surgeons the resources to carry out a surgical procedure that is simpler to perform and easier to recover from. Furthermore, unicompartmental knee arthroplasty is associated with fewer postoperative complications and lower mortality and is equal to or better than total knee arthroplasty.

Increased Operative Time Impacts Rates of Short-Term Complications After Unicompartmental Knee Arthroplasty.

BACKGROUND: Previous evidence has demonstrated an exacerbating effect of increased operative time on short-term complications in total joint arthroplasty. While the same relationship may be expected for unicompartmental knee arthroplasty (UKA), supporting evidence remains sparse. The purpose of this study is to determine the impact of operative time on short-term complication rates after UKA and determine a critical threshold in operative times after which complications may increase. METHODS: The American College of Surgeons National Surgical Quality Improvement Project was queried from 2007 to 2018 to identify 11,633 UKA procedures that were included in the final analysis. The effect of operative time on complications within 30 days was evaluated using multivariate logistic regression models. Receiver operating characteristics curves and spline regression models were used to identify critical thresholds in operative time that increase the likelihood of short-term complications. RESULTS: Longer operative times (in minutes) were associated with higher rates of surgical site infection (90.4 ± 26.7 vs 84.8 ± 25.5, P = .003), blood transfusions (94.9 ± 28.6 vs 84.9 ± 25.5, P = .007), as well as reoperation rates (90.8 ± 27.9 vs 84.9 ± 25.5, P = .01), extended hospital length of stay (93.4 ± 29.8 vs 84.5 ± 25.2, P < .001), and mortality (110.4 ± 35.5 vs 84.9 ± 25.5, P = .008). Following multivariate logistic regression, operative time was found to independently predict increased surgical site infection, blood transfusion, myocardial infarction, extended length of stay, and mortality (odds ratio: 1.09 - 1.45, CI: 1.01 - 1.91, all P values <0.02). Receiver operating characteristics curves found an increase in mortality risk during the 30-day postoperative period after 88.5 minutes of operative time, a finding supported by spline regression plots. CONCLUSION: The present study found a positive correlation between increased operative times and short-term postoperative complication rates after UKA. Despite a statistically significant association with increasing operative time, odds ratios of reported complications are relatively low.

Lysis of Adhesion for Arthrofibrosis After Total Knee Arthroplasty Is Associated With Increased Risk of Subsequent Revision Total Knee Arthroplasty.

BACKGROUND: The aim of this study is to determine incidence of lysis of adhesion (LOA) for postoperative arthrofibrosis following primary total knee arthroplasty (TKA), patient factors associated with LOA, and impact of LOA on revision TKA. METHODS: Patients who underwent primary TKA were identified in the Humana and Medicare databases. Patients who underwent LOA within 1 year after TKA were defined as the "LOA" cohort. Multiple binomial logistic regression analyses were performed to identify patient factors associated with undergoing LOA within 1 year after index TKA, and identify risk factors including LOA on risk for revision TKA within 2 years of index TKA. RESULTS: In total, 58,538 and 48,336 patients underwent primary TKA in the Medicare and Humana databases, respectively. Incidence of LOA within 1 year after TKA was 0.56% in both databases. Age <75 years was a significant predictor of LOA in both databases (P < .05 for both). Incidence of revision TKA was significantly higher for the "LOA" cohort when compared to the "TKA Only" cohort in both databases (P < .0001 for both). LOA was the strongest predictor of revision TKA within 2 years after index TKA in both databases (P < .0001 for both). Additionally, age <65 years, male gender, obesity, fibromyalgia, smoking, alcohol abuse, and history of anxiety or depression were independently associated with increased odds of revision TKA within 2 years after index TKA (P < .05 for all). CONCLUSION: Incidence of LOA after primary TKA is low, with younger age being the strongest predictor for requiring LOA. Patients who undergo LOA for arthrofibrosis within 1 year after primary TKA have a substantially high risk for subsequent early revision TKA. LEVEL OF EVIDENCE: III, Retrospective Cohort Study.

Clinical Outcomes in Isolated Tibial Revision With Cruciate Retaining Total Knee Arthroplasty.

BACKGROUND: Tibial component loosening is one of the most common modes of failure in contemporary total knee arthroplasty (TKA). Limited literature is available on the outcomes of isolated tibial revision with retention of the cruciate retaining (CR) femoral component. The purpose of this study was to determine the results of isolated tibial revisions in CR TKA. METHODS: We identified 135 patients who underwent an isolated tibial revision after a primary CR TKA from our institutional registry between January 2007 and January 2017. The mean time between the primary and revision was 2.9 years (range 0.1-15.4). Revision with a press-fit stem was performed in 79 patients and 56 patients were revised with a fully cemented stem. Patients were evaluated at a minimum of two years using Knee Society Score, Knee Injury and Osteoarthritis Score for Joint Replacement, and radiography. Implant survivorship was determined using Kaplan-Meier survival analysis. RESULTS: At a mean follow-up of 5.1 years, there were six (4.4%) repeat revisions: three for periprosthetic infection (2.2%), two for instability (1.5%), and one for a fractured tibial stem (0.7%). The mean Knee Society Score and Knee Injury and Osteoarthritis Score for Joint Replacement increased from 51.6 and 56.1 preoperatively to 90.1 and 89.7 after surgery (P < .001). Survivorship free of repeat revision for any cause was 93.3% at 5 years, and aseptic revision survivorship was 95.8% at 5 years. No implants were radiographically loose. CONCLUSION: In patients with isolated tibial loosening and a well-fixed and well-positioned CR femoral component, isolated tibial revision provides excellent early to midterm implant survivorship and clinical outcomes with a low risk of instability and recurrent tibial loosening.

Outcomes of Isolated Head and Liner Exchange Using Large Femoral Heads and Modern Liners in Revision Total Hip Arthroplasty.

BACKGROUND: Previous reports on the outcomes of isolated head and liner exchange in revision total hip arthroplasty have found high rates of instability after these surgeries. Most reports have studied constructs using ≤28 mm femoral heads. The purpose of this study was to determine if modern techniques with the use of larger head sizes can improve the rate of instability after head and liner exchange. METHODS: We identified 138 hips in 132 patients who underwent isolated head and liner exchange for polyethylene wear/osteolysis (57%), acute infection (27%), metallosis (13%), or other (2%). All patients underwent revision with either 32 (23%), 36 (62%), or 40 (15%) mm diameter heads. Cross-linked polyethylene was used in all revisions. Lipped and/or offset liners were used in 104 (75%) hips. Average follow-up was 3.5 (1.0-9.1) years. Statistical analyses were performed with significance set at P < .05. RESULTS: Revision-free survivorship for any cause was 94.6% and for aseptic causes was 98.2% at 5 years. 11 (8%) hips experienced a complication with 7 (5%) hips requiring additional revision surgery. After revision, 4 (3%) hips experienced dislocation, 5 (4%) hips experienced infection, and 1 (1%) hip was revised for trunnionosis. No demographic or surgical factors significantly affected outcomes. CONCLUSION: Our study shows that isolated head and liner exchange using large femoral heads and modern liners provides for better stability than previous reports. The most common complication was infection. We did not identify specific patient, surgical, or implant factors that reduced the risk of instability or other complication.

General Anesthesia Leads to Increased Adverse Events Compared With Spinal Anesthesia in Patients Undergoing Unicompartmental Knee Arthroplasty.

BACKGROUND: The volume of unicompartmental knee arthroplasty (UKA) has increased dramatically in recent years with good reported long-term outcomes. UKA can be performed under general or neuraxial (ie, spinal) anesthesia; however, little is known as to whether there is a difference in outcomes based on anesthesia type. The purpose of the present study is to compare perioperative outcomes between anesthesia types for patients undergoing primary elective UKA. METHODS: Patients who underwent primary elective UKA from 2007 to 2017 were identified from the American College of Surgeons-National Surgical Quality Improvement Program Database. Operating room times, length of stay (LOS), 30-day adverse events, and readmission rates were compared between patients who received general anesthesia and those who received spinal anesthesia. Propensity-adjusted multivariate analysis was used to control for selection bias and baseline patient characteristics. RESULTS: A total of 8639 patients underwent UKA and met the inclusion criteria for this study. Of these, 4728 patients (54.7%) received general anesthesia and 3911 patients (45.3%) received spinal anesthesia. On propensity-adjusted multivariate analyses, general anesthesia was associated with increased operative time (P < .001) and the occurrence of any severe adverse event (odds ratio [OR], 1.39; 95% confidence interval [95% CI], 1.04-1.84; P = .024). In addition, general anesthesia was associated with higher rates of deep venous thrombosis (OR, 2.26; 95% CI, 1.11-4.6; P = .024) and superficial surgical site infection (OR, 1.04; 95% CI, 0.6-1.81; P < .001). Finally, general anesthesia was also associated with a reduced likelihood of discharge to home (OR, 0.72; 95% CI, 0.59-0.88; P < .001). No difference existed in postoperative hospital LOS or readmission rates among cohorts. CONCLUSION: General anesthesia was associated with an increased rate of adverse events and increased operating room times as well as a reduced likelihood of discharge to home. There was no difference in hospital LOS or postoperative readmission rates between anesthesia types.

Dilute Betadine Lavage Reduces the Risk of Acute Postoperative Periprosthetic Joint Infection in Aseptic Revision Total Knee and Hip Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized, controlled trial is to determine whether dilute betadine lavage compared to normal saline lavage reduces the rate of acute postoperative periprosthetic joint infection (PJI) in aseptic revision total knee (TKA) and hip arthroplasty (THA). METHODS: A total of 478 patients undergoing aseptic revision TKA and THA were randomized to receive a 3-minute dilute betadine lavage (0.35%) or normal saline lavage before surgical wound closure. Fifteen patients were excluded following randomization (3.1%) and six were lost to follow-up (1.3%), leaving 457 patients available for study. Of them, 234 patients (153 knees, 81 hips) received normal saline lavage and 223 (144 knees, 79 hips) received dilute betadine lavage. The primary outcome was PJI within 90 days of surgery with a secondary assessment of 90-day wound complications. A priori power analysis determined that 285 patients per group were needed to detect a reduction in the rate of PJI from 5% to 1% with 80% power and alpha of 0.05. RESULTS: There were eight infections in the saline group and 1 in the betadine group (3.4% vs 0.4%, P = .038). There was no difference in wound complications between groups (1.3% vs 0%, P = .248). There were no differences in any baseline demographics or type of revision procedure between groups, suggesting appropriate randomization. CONCLUSION: Dilute betadine lavage before surgical wound closure in aseptic revision TKA and THA appears to be a simple, safe, and effective measure to reduce the risk of acute postoperative PJI. LEVEL OF EVIDENCE: Level I.

Are Postoperative Hip Precautions Necessary After Primary Total Hip Arthroplasty Using a Posterior Approach? Preliminary Results of a Prospective Randomized Trial.

BACKGROUND: It is unclear whether posterior hip precautions after primary total hip arthroplasty (THA) reduce the incidence of early postoperative dislocation. METHODS: We performed a prospective randomized study to evaluate the effect of hip precautions on incidence of early dislocation after primary THA using a posterior approach. Between January 2016 and April 2019, 587 patients (594 hips) were consented and randomized into restricted or unrestricted groups. No significant demographic or surgical differences existed between groups. The restricted group was instructed to refrain from hip flexion >90°, adduction across midline, and internal rotation for 6 weeks. 98.5% (585 of 594) of hips were available for minimum 6-week follow-up (291 restricted and 294 unrestricted). Power analysis showed that 579 hips per group are needed to demonstrate an increase in dislocation rate from 0.5% to 2.5% with 80% power. RESULTS: At average follow-up of 15 weeks (range, 6-88), there were 5 dislocations (incidence, 0.85%). Three posterior dislocations occurred in the restricted group at a mean of 32 days (range, 17-47), and 2 posterior dislocations occurred in the unrestricted group at a mean of 112 days (range, 21-203), with no difference in dislocation rate between groups (1.03% vs 0.68%; odds ratio, 0.658; 95% confidence interval, 0.11-3.96; P = .647). At 6 weeks, unrestricted patients endorsed less difficulty with activities of daily living, earlier return to driving, and more time spent side sleeping (P < .05). CONCLUSION: Preliminary analysis suggests that removal of hip precautions after primary THA using a posterior approach was not associated with early dislocation and facilitated return to daily functions. Investigation to appropriate power is warranted.

External Validity of a New Prediction Model for Patient Satisfaction After Total Knee Arthroplasty.

BACKGROUND: The ability to identify patients at risk of dissatisfaction after total knee arthroplasty (TKA) remains elusive. This study's purpose was to determine the external validity of a recently published prediction model for patient satisfaction (PMPS) with the hypothesis that it would achieve similar predictive success in our study sample. METHODS: A 10-question PMPS statistically derived from 5 patient-reported outcome questionnaires was tested for external validity in this prospective cohort investigation. The PMPS incorporates gender, age, stiffness, noise, and pain catastrophizing, with a score of 20 or greater predictive of satisfaction. As in the original study, to determine satisfaction the 2011 Knee Society Score (KSS) satisfaction subscale was collected at 3 months postoperatively. Two hundred seventy-four patients were administered the PMPS preoperatively, and 145 patients completed the KSS at 3 months postoperatively (53.0% response rate; 59% female; age, 64.9; body mass index, 32.5). A Bland-Altman analysis to assess agreement was performed. RESULTS: One hundred thirty-three patients (91.7%) were satisfied and 12 (8.3%) were dissatisfied based on their postoperative KSS. The mean difference between the PMPS and KSS was 3.6 ± 8, but with a 95% prediction interval of -15.3 to 22.1 signifying almost no correlation. The PMPS did not predict any of the 12 dissatisfied patients postoperatively, and falsely predicted 5 patients to be dissatisfied of which 4 actually had a maximum postoperative KSS of 40. CONCLUSION: A previously published, internally validated 10-question PMPS was unable to predict satisfaction after TKA in our external study sample. This study emphasizes the difficulty of developing a simple, but robust questionnaire that consistently predicts patient satisfaction after TKA.

The James A. Rand Young Investigator's Award: Large Opioid Prescriptions Are Unnecessary After Total Joint Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized controlled trial is to determine whether the quantity of opioid pills prescribed at discharge is associated with the number of opioid pills consumed or unused by patients after primary hip and knee arthroplasty within 30 days after discharge. METHODS: A total of 304 opioid-naïve patients were randomized to receive either 30 or 90 5-mg oxycodone immediate-release (OxyIR) pills at discharge. Daily opioid consumption, number of unused pills, and pain scores were calculated for 30 days with a patient-completed medication diary. Statistical analysis involved t-test, rank-sum, chi-squared tests, and multiple linear regression with alpha = 0.05. RESULTS: Of the 304 patients randomized, 161 patients were randomized to receive 30 pills and 143 to receive 90. In the first 30 days after discharge, the median number of unused pills was 15 in the 30 group vs 73 in the 90 group (P < .001). Within 90 days of discharge, 26.7% of the 30 group and 10.5% of the 90 group requested a refill (P < .001), leading to a mean of 777.1 ± 414.2 morphine equivalents vs 1089.7 ± 536.4 prescribed (P < .0001). There was no difference between groups in mean morphine equivalents consumed. Regression analysis demonstrated that being prescribed 90 OxyIR pills was independently associated with taking more OxyIR pills (P = .028). There was no difference in pain scores within the first 30 days and in patient-reported outcome scores at 6 weeks postoperatively. CONCLUSION: Prescribing fewer OxyIR pills is associated with a significant reduction in unused opioid pills and decreased opioid consumption with no increase in pain scores and no difference in patient-reported outcomes. LEVEL OF EVIDENCE: Level I. Randomized controlled trial.

Physical Therapy on Postoperative Day Zero Following Total Knee Arthroplasty: A Randomized, Controlled Trial of 394 Patients.

BACKGROUND: Surgeons have increasingly emphasized early mobilization as a way to facilitate discharge following total knee arthroplasty (TKA). The purpose of this study was to determine whether starting formal physical therapy (PT) the afternoon of postoperative day (POD) 0, instead of starting PT the morning of POD 1, could shorten hospital length of stay (LOS). METHODS: Patients undergoing elective TKA with a planned minimum 1-night hospital stay were randomized to start formal PT the afternoon following surgery or the morning of POD 1. LOS in hours was the primary outcome. An a priori sample size calculation suggested that 394 patients were required to show a 4-hour difference between groups. RESULTS: Out of 394 patients enrolled and randomized, 378 (95.9%) completed the study. The observed difference in hospital LOS was not large enough to be of clinical significance (intention-to-treat analysis: median of 32.0 hours for POD 0 PT vs 31.0 hours for POD 1 PT, P = .65; as-treated analysis: median of 31.0 hours for POD 0 PT vs 32.0 hours for POD 1 PT, P = .12). Similarly, the observed differences in satisfaction with inpatient PT (10.0 vs 10.0, P = .77), patient-reported readiness for discharge at time of discharge (10.0 vs 10.0, P = .97), and POD 0 pain (3.3 vs 4.0, P = .79) were not large enough to be of clinical significance. CONCLUSION: While PT on the day of surgery has been suggested as one method to facilitate discharge following TKA, this randomized trial did not demonstrate clinically meaningful differences in hospital LOS or patient satisfaction when PT is initiated on the day of surgery vs on the morning after surgery.

Prospective Validation of a Demographically Based Primary Total Knee Arthroplasty Size Calculator.

BACKGROUND: Preoperative planning for total knee arthroplasty (TKA) is essential for streamlining operating room efficiency and reducing costs. Digital templating and patient-specific instrumentation have shown some value in TKA but require additional costs and resources. The purpose of this study was to validate a previously published algorithm that uses only demographic variables to accurately predict TKA tibial and femoral component sizes. METHODS: Four hundred seventy-four consecutive patients undergoing elective primary TKA were prospectively enrolled. Four surgeons were included, three of which were unaffiliated with the retrospective cohort study. Patient sex, height, and weight were entered into our published Arthroplasty Size Prediction mobile application. Accuracy of the algorithm was compared with the actual sizes of the implanted femoral and tibial components from 5 different implant systems. Multivariate regression analysis was used to identify independent risk factors for inaccurate outliers for our model. RESULTS: When assessing accuracy to within ±1 size, the accuracies of tibial and femoral components were 87% (412/474) and 76% (360/474). When assessing accuracy to within ±2 sizes of predicted, the tibial accuracy was 97% (461/474), and the femoral accuracy was 95% (450/474). Risk factors for the actual components falling outside of 2 predicted sizes include weight less than 70 kg (odds ratio = 2.47, 95% confidence interval [1.21-5.06], P = .01) and use of an implant system with <2.5 mm incremental changes between femoral sizes (odds ratio = 5.50, 95% confidence interval [3.33-9.11], P < .001). CONCLUSIONS: This prospective series of patients validates a simple algorithm to predict component sizing for TKA with high accuracy based on demographic variables alone. Surgeons can use this algorithm to simplify the preoperative planning process by reducing unnecessary trays, trials, and implant storage, particularly in the community or outpatient setting where resources are limited. Further assessment of components with less than 2.5-mm differences between femoral sizes is required in the future to make this algorithm more applicable worldwide.

Is There Any Role for Direct Repair of Extensor Mechanism Disruption Following Total Knee Arthroplasty?

BACKGROUND: Extensor mechanism disruption remains a challenging problem in total knee arthroplasty (TKA) with historically poor outcomes. The purpose of our study is to determine if patients undergoing acute extensor mechanism repair had different outcomes than patients undergoing allograft reconstruction. METHODS: We reviewed a series of 126 total knee arthroplasty patients requiring surgical repair or reconstruction of an extensor mechanism injury from 2005 to 2014 with a minimum of 24 months of follow-up. Demographics, comorbidities, Knee Society Scores, time from injury, and reoperations were all recorded from the medical record. A poor outcome was defined as an extensor lag >30°, postoperative Knee Society Scores <60, or a reoperation. A multivariate analysis was then performed to identify independent risk factors for a poor outcome. RESULTS: Of the 126 patients, there were 58 patients who underwent direct extensor repair (46%) and 68 patients who underwent allograft reconstruction (54%) at a mean postsurgical follow-up of 81.2 months. Rates of poor outcomes were comparably high in both groups (33% vs 44%, P = .192). Patella tendon repair had the highest rate of poor outcomes compared to quadriceps repair and patella fixation (63% vs 22% vs 8%, P = .002). Independent risk factors for poor outcomes included patients with a history of infection (odds ratio 4.559, P = .002) and injury greater than 2 weeks duration (odds ratio 4.237, P = .031). CONCLUSION: Outcomes following direct extensor mechanism are comparable to extensor mechanism allograft reconstruction; however, patients should be counseled regarding poor outcomes. Direct repair of patellar tendon injuries should likely be avoided due to prohibitively high complication rate.

Continuous Adductor Canal Blocks Provide Superior Ambulation and Pain Control Compared to Epidural Analgesia for Primary Knee Arthroplasty: A Randomized, Controlled Trial.

BACKGROUND: Adductor canal blocks (ACBs) are an alternative to femoral nerve blocks that minimize lower extremity weakness. However, it is unclear whether this block will provide analgesia that is equivalent to techniques, such as epidural analgesia. The purpose of this randomized controlled trial was to compare continuous ACBs with epidural analgesia for primary total knee arthroplasty. METHODS: Following institutional review board approval, 145 patients were randomized to 1 of 3 groups: combined spinal-epidural (CSE), spinal + continuous ACB (CACB), or general + CACB. Epidural analgesia was used postoperatively in the CSE group, and an adductor canal catheter was used in the CACB groups. Power analysis determined that 84 patients per group were needed to demonstrate a 35% increase in ambulation with an alpha of 0.05 at a power of 90%. RESULTS: At interim analysis, 13 patients were removed for protocol deviations, leaving 45 in CSE, 41 in spinal + CACB and 46 in general + CACB groups. Patient demographics were similar in all comparisons suggesting appropriate randomization. Patients in the CACB groups walked further on postoperative day 1, 2, and 3 (P = .02). Mean daily pain scores were lower in the CACB groups (4.1 CSE, 3.0 spinal + CACB, 3.4 general + CACB, P = .009). There was no significant difference in total opioid consumption between groups (158 morphine equivalents CSE, 149 spinal + CACB, and 172 general + CACB). More patients reported being "very satisfied" in CACB groups (68% general + CACB, 63% spinal + CACB, and 36% CSE; P = .001). CONCLUSION: Continuous adductor analgesia provides superior ambulation, lower pain scores, faster discharge, and greater patient satisfaction when compared to epidural analgesia for primary total knee arthroplasty.

The James A. Rand Young Investigator's Award: A Randomized Controlled Trial of Oral and Intravenous Tranexamic Acid in Total Knee Arthroplasty: The Same Efficacy at Lower Cost?

BACKGROUND: Tranexamic acid (TXA) is a synthetic antifibrinolytic agent successfully used intravenously (IV) to reduce blood loss after total knee arthroplasty (TKA). An oral formulation of the medication is available, at a fraction of the cost of the IV preparation. The purpose of this randomized controlled trial is to determine if oral TXA is equivalent to IV TXA in reducing blood loss in TKA. METHODS: In this double-blinded, placebo-controlled trial, patients undergoing primary TKA were randomized to receive 1.95g of TXA orally 2 hours preoperatively or 1g IV bolus before wound closure. The primary outcome was reduction of hemoglobin. Power analysis determined that 30 patients were required in each group. Equivalence analysis was performed with pooled and Satterthwaite t tests with a P-value of <.05 suggesting equivalence between treatments. RESULTS: Thirty-four patients received oral TXA and 37 patients received IV TXA. There was no difference in the mean reduction of hemoglobin between oral and IV groups (3.45g/dL vs 3.31g/dL, respectively; P = .001, equivalence), and total blood loss was equivalent at 1281 mL vs 1231 mL, respectively (P = .02, equivalence). One patient in each group was transfused. CONCLUSION: Oral TXA provides equivalent reductions in blood loss, at a cost of $14 compared with $47-$108 depending on the IV formulation selected. As approximately 700,000 primary TKA are performed in the United States annually, a switch to oral TXA could yield total cost savings of between $23 million and $67 million dollars per year for our health care system.

Army orthopaedic surgery residency program directors' selection criteria.

Factors associated with successful selection in U.S. Army orthopaedic surgical programs are unreported. The current analysis includes survey data from all Army orthopaedic surgery residency program directors (PDs) to determine these factors. PDs at all Army orthopaedic surgery residency programs were provided 17 factors historically considered critical to successful selection and asked to rank order the factors as well as assign a level of importance to each. Results were collated and overall mean rankings are provided. PDs unanimously expressed that performance during the on-site orthopaedic surgery rotation at the individual program director's institution was most important. Respondents overwhelmingly reported that Steps 1 and 2 licensing exam scores were next most important, respectively. Survey data demonstrated that little importance was placed on letters of recommendation and personal statements. PDs made no discriminations based on allopathic or osteopathic degrees. The most important factors for Army orthopaedic surgery residency selection were clerkship performance at the individual PD's institution and licensing examination score performance. Army PDs consider both USMLE and COMLEX results, because Army programs have a higher percentage of successful osteopathic applicants.

Painful Unicompartmental Knee Arthroplasty: Etiology, Diagnosis and Management.

Unicompartmental knee arthroplasty (UKA) is an increasingly common procedure. Patients with persistent or new postoperative pain can present a challenge for surgeons to accurately diagnose and treat. The purpose of this study is to provide a comprehensive review of the presentation, diagnosis, and management of the various pathologies contributing to pain after UKA. The most common causes of a painful UKA include aseptic component loosening and progression of osteoarthritis. Both of these conditions may be treated with either revision UKA or conversion to total knee arthroplasty. While technically challenging, these procedures are often associated with favorable outcomes. Other causes of pain after UKA include infection, atraumatic tibial component subsidence, periprosthetic fracture and malalignment. Careful clinical, radiographic, and laboratory evaluation is therefore critical to accurately identify the source of pain and guide appropriate management.

Preoperative Corticosteroid Injections Are Not Associated with Deep Infection after Unicompartmental Knee Arthroplasty.

Prior to unicompartmental knee arthroplasty (UKA), corticosteroid injections (CSI) are a common nonoperative treatment for arthritis. It is unclear whether CSI prior to UKA impacts the likelihood of postoperative infection. This study sought to determine if there is a time- and/or dose-dependent relationship between preoperative CSI and postoperative infection. An administrative claims database was queried for patients undergoing UKA with more than 1 year of pre-enrollment and follow-up. Of 31,676 patients with a UKA who met enrollment criteria, 8,628 patients had a CSI 0 to 3 months prior to surgery, 111 had a CSI 3 to 12 months prior to surgery, and 22,937 never received an injection. Overall, 246 postoperative deep infections were reported (0.8%). Time-dependent and dose-dependent relationships were modeled using multivariable logistic regressions. Postoperative deep infections occurred in 64 patients with CSI 0 to 3 months prior to surgery (0.7%), compared with 0 patients with CSI 3 to 12 months before surgery (0.0%) and 182 controls (0.8%, p = 0.58). CSI within 1 month prior to UKA was not statistically associated with postoperative infection (p = 0.66). Two or more CSI within 3 months prior to UKA were associated with a twofold elevated odds of infection, compared with receiving a single injection (odds ratio [OR]: 2.08, p = 0.03). Univariable predictors of infection included younger age, increasing Charlson Comorbidity Index, smoking, asthma, chronic obstructive pulmonary disease, chronic kidney disease, diabetes, liver disease, and obesity. Multivariable analysis controlling for these characteristics elicited no relationship between recent CSI administration and postoperative infection. CSI within 3 months of surgery (1.5%) or 3 to 12 months (1.8%) were associated with increased conversion to total knee arthroplasty (TKA) compared with those who did not receive an injection (1.1%, p = 0.01), although TKA for indication of periprosthetic joint infection was not statistically different (p = 0.72). Preoperative CSI within 3 months of UKA is not associated with postoperative infection, although significant medical comorbidity does show an association. Preoperative CSI is associated with increased conversion from UKA to TKA for noninfectious indications.

Late Manipulation under Anesthesia after Total Knee Arthroplasty: Improved Range of Motion and a Low Complication Rate.

The purpose of this study was to evaluate outcomes of late manipulation under anesthesia (MUA) for stiffness performed from ≥12 weeks to more than a year after primary total knee arthroplasty (TKA). A total of 152 patients receiving MUA ≥12 weeks after primary TKA from 2014 to 2021 were reviewed. The primary outcome measured was change in range of motion (ROM). We tracked intraoperative complications and the need for repeat MUA or open procedure for continued stiffness after initial MUA. Three subgroups were analyzed: Group 1 included 58 knees between 12 weeks and 6 months after TKA, Group 2 included 44 knees between 6 and 12 months after TKA, and Group 3 included 50 knees ≥12 months after TKA. Analysis included descriptive statistics and univariate analysis, with α <0.05. Groups 1 to 3 all significantly increased their overall ROM by 20.9, 19.2, and 22.0 degrees, respectively. All groups significantly increased their flexion and extension from preoperatively. Group 1 had one intraoperative supracondylar femur fracture (1.7%) requiring open reduction and internal fixation, and five patients required repeat MUA or open procedure (8.6%). Group 2 had no intraoperative fractures, and five patients required repeat MUA or open procedure (11.4%). Group 3 had one intraoperative tibial tubercle avulsion fracture managed conservatively (2.0%) and one repeat MUA (2.0%). Late MUA resulted in significantly improved ROM in all groups. ROM improved more as the time from index TKA increased, although statistically insignificant. Repeat MUA or open procedure rate decreased with MUA ≥12 months from TKA, although statistically insignificant. The overall intraoperative fracture risk was 1.3%.