Oxidative stress mediates associations between preoperative psychosocial phenotype and pain-related outcomes at 6 months following total knee arthroplasty: a longitudinal cohort study.

OBJECTIVE: Greater preoperative depression, anxiety, and pain catastrophizing are associated with more severe long-term pain following total knee arthroplasty (TKA). In a secondary analysis of previously reported data, we tested the hypothesis that these associations are mediated by oxidative stress (OS). DESIGN: A mixed between/within-subjects longitudinal cohort design. SETTING: A single academic medical center. SUBJECTS: Osteoarthritis patients (n = 91; 62.6% female) undergoing unilateral TKA. METHODS: We assessed depression, anxiety, and catastrophizing, as well as markers of central sensitization (widespread pain, temporal summation of pain) preoperatively. Blood samples were then obtained immediately prior to intraoperative tourniquet placement for quantification of in vivo biomarkers of systemic OS, F2-isoprostanes and isofurans. Post-TKA pain intensity (numeric rating scale worst pain [NRS], McGill Pain Questionnaire-2 [MPQ-2]) and function (PROMIS Pain Interference) were assessed at 6 months following TKA. RESULTS: Greater preoperative depression, catastrophizing, and widespread pain were associated with higher intraoperative combined OS (F2-isoprostanes+isofurans/2), which was in turn associated with higher post-TKA pain intensity and worse function (P < .05). All preoperative phenotype predictors except anxiety were correlated positively with post-TKA pain and/or function (P < .05). Bootstrapped mediation analyses revealed significant (P < .05) indirect (mediated) effects of depression (NRS Worst Pain, MPQ-2, PROMIS Pain Interference), anxiety (MPQ-2, PROMIS Pain Interference), and catastrophizing (PROMIS Pain Interference) on adverse long-term post-TKA outcomes via elevated OS. Central sensitization-related predictors demonstrated only direct effects (P < .05) on post-TKA outcomes that were independent of OS mechanisms. CONCLUSIONS: Results suggest that the adverse impact of depression, anxiety, and pain catastrophizing on post-TKA pain and functional outcomes are mediated in part by elevated OS.

Central Sensitization: The Missing Link Between Psychological Distress and Poor Outcome Following Primary Total Knee Arthroplasty.

BACKGROUND: While preoperative psychological distress is known to predict risk for worse total knee arthroplasty (TKA) outcomes, distress may be too broad and nonspecific a predictor in isolation. We tested whether there are distinct preoperative TKA patient types based jointly on psychological status and measures of altered pain processing that predict adverse clinical outcomes. METHODS: In 112 TKA patients, we preoperatively assessed psychological status (depression, anxiety, and catastrophizing) and altered pain processing via a simple quantitative sensory testing protocol capturing peripheral and central pain sensitization. Outcomes (pain, function, opioid use) were prospectively evaluated at 6 weeks and 6 months after TKA. Cluster analyses were used to empirically identify TKA patient subgroups. RESULTS: There were 3 distinct preoperative TKA patient subgroups identified from the cluster analysis. A low-risk (LR) group was characterized by low psychological distress and low peripheral and central sensitization. In addition, 2 subgroups with similarly elevated preoperative psychological distress were identified, differing by pain processing alterations observed: high-risk centralized pain and high-risk peripheral pain. Relative to LR patients, high-risk centralized pain patients displayed significantly worse function and greater opioid use at 6 months after TKA (P values <.05). The LR and high-risk peripheral pain patient subgroups had similar 6-month outcomes (P values >.05). CONCLUSIONS: Among patients who have psychological comorbidity, only patients who have central sensitization were at elevated risk for poor functional outcomes and increased opioid use. Central sensitization may be the missing link between psychological comorbidity and poor TKA clinical outcomes. Preoperative testing for central sensitization may have clinical utility for improving risk stratification in TKA patients who have psychosocial risk factors.

Is a Failed Spinal Attempt Associated with a Worse Clinical Course Following Primary Total Hip and Knee Arthroplasty?

INTRODUCTION: Spinal anesthesia (SA) is the preferred anesthesia modality for total joint arthroplasty (TJA). However, studies establishing SA as preferential may be subject to selection bias given that general anesthesia (GA) is often selectively utilized on more difficult, higher-risk operations. The optimal comparison group, therefore, is the patient converted to GA due to a failed attempt at SA. The purpose of this study was to determine risk factors and outcomes following failed SA with conversion to GA during primary total hip (THA) or knee arthroplasty (TKA). METHODS: A consecutive cohort of 4,483 patients who underwent primary TJA at our institution was identified (2,004 THA and 2,479 TKA). Of these patients, 3,307 underwent GA (73.8%), 1,056 underwent SA (23.3%), and 130 patients failed SA with conversion to GA (2.90%). Primary outcomes included rescue analgesia requirement in the post-anesthesia care unit (PACU), time to ambulation, pain scores in the PACU, estimated blood loss (EBL), and 90-day complications. RESULTS: Risk factors for SA failure included older age and a higher comorbidity burden. Failure of SA was associated with increased EBL, rescue intravenous (IV) opioid use, and time to ambulation when compared to the successful SA group in both THA and TKA patients (P < 0.001). The anesthesia modality was not associated with significant differences in PACU pain scores. The 90-day complication rate was similar between the failed SA and GA groups. There was a higher incidence of post-operative pain prompting unplanned visits and thromboembolism when comparing failed SA to successful SA in both THA and TKA patients (P < 0.05). CONCLUSION: In our series, patients who had failed SA demonstrated inferior outcomes to patients receiving successful SA and similar outcomes to patients receiving GA who did not have an SA attempt. This emphasizes the importance of success in the initial attempt at SA for optimizing outcomes following TJA.

2022 American Association of Hip and Knee Surgeons Symposium: Periprosthetic Joint Infection.

Periprosthetic joint infection (PJI) is the leading cause of failure in patients undergoing total joint arthroplasty. This article is a brief summary of a symposium on PJI that was presented at the annual AAHKS meeting. It will provide an overview of current technqiues in the prevention, diagnosis, and management of PJI. It will also highlight emerging technologies in this setting.

Trends in Total Knee Arthroplasty Cementing Technique Among Arthroplasty Surgeons-A Survey of the American Association of Hip and Knee Surgeons Members.

BACKGROUND: Aseptic loosening persists as one of the leading causes of failure following cemented primary total knee arthroplasty (TKA). Cement technique may impact implant fixation. We hypothesized that there is variability in TKA cement technique among arthroplasty surgeons. METHODS: A 28-question survey regarding variables in surgeons' preferred TKA cementation technique was distributed to 2,791 current American Association of Hip and Knee Surgeons (AAHKS) members with a response rate of 30.8% (903 respondents). Patterns of responses were analyzed by grouping respondents by their answers to certain questions including cementing technique, tibial cement location, and femoral cement location. RESULTS: A total of 73.5% reported performing at least 7 of 8 of the highest consensus techniques, including vacuum mixing (79.9%), using two bags (76.1%), tibial implant first (95.2%), single-stage cementing (96.9%), compression of the implants in extension (91.7%), and use of a tourniquet (84.3%). Medium and high viscosity cement was most commonly used (37.9 and 37.8%, respectively). Finger pressurization was most common (76.1%) compared to a gun (29.8%). There were 26.5% of respondents performing 6 or fewer of the most common majority techniques and seemed to perform other less common techniques (eg, use of a single bag of cement, trialing or closure prior to cement curing, and heating to accelerate cement curing). Cement was most commonly applied to the entire bone and implant surface on both the tibia (46.4%) and femur (47.7%), leaving much variation in the remaining cement application location responses. DISCUSSION: There appears to be variability in cemented TKA technique among arthroplasty surgeons. There were 26.5% of respondents performing less of the majority techniques and also performed other additional low-response rate techniques. Further studies that look at the impacts of variation in techniques on outcomes may be warranted. Our study demonstrates the need for defining best practices for cement technique given the substantial variability identified.

Spinal Anesthetic Type and Independent Risk Factors for Postoperative Urinary Retention Following Total Joint Arthroplasty.

While risk factors for postoperative urinary retention (POUR) after total joint arthroplasty (TJA) have been identified, its association with type of spinal anesthetic has not yet been thoroughly investigated. Patients undergoing primary TJA between 2013-2018 were reviewed. From August 2013 to March 2016 bupivacaine was primarily given and from March 2016 through August 2018, most, although not all, received mepivacaine. Patient demographics as well as intraoperative data were recorded. One-thousand and fifty-four patients were included. POUR rates were not significantly different between groups (5.5% vs 6.1%, p = 0.675). Those who received mepivacaine had a significantly shorter length of stay (LOS) (1 vs. 2 days, p < 0.001). However, spinal anesthetic type was not significantly associated with either POUR or LOS after controlling for between-group differences. Older age (odds ratio [OR] 1.024 [95% confidence interval {CI}:1.000-1.049]; p = 0.049) and a history of benign prostatic hyperplasia or urinary incontinence/retention (OR 2.155 [95% CI:1.114-4.168]; p = 0.023) were confirmed as independent risk factors for POUR. (Journal of Surgical Orthopaedic Advances 29(4):225-229, 2020).

Do Corticosteroids Attenuate the Peri-Operative Acute Phase Response After Total Knee Arthroplasty?

BACKGROUND: Following tissue injury, the acute phase response (APR) functions to survive and then repair injured tissue. An exuberant APR, which can be evoked by total knee arthroplasty (TKA), results in a hyper-inflammatory state, leading to pain, nausea, venous thromboembolism, or potentially life-threatening complications. Here, we observed the effects of peri-operative dexamethasone on the APR following TKA by trending C-reactive protein (CRP, mg/L) and fibrinogen (mg/dL). We hypothesize that the anti-inflammatory effects of dexamethasone can attenuate the APR after TKA and will be associated with decreased post-operative pain and nausea. METHODS: A retrospective case-control study was performed on 188 unilateral TKA procedures. The patients were divided into a group receiving dexamethasone (10 mg intra-operatively and on post-operative day [POD] 1) and a group receiving no corticosteroids. Post-operative CRP, fibrinogen, morphine equivalents, and anti-emetic doses were recorded. RESULTS: Compared to the non-steroid group, patients receiving dexamethasone yielded a significantly decreased CRP on POD0 (5.5 vs 8.3), POD1 (11.8 vs 22.0), and POD2 (85.5 vs 148.9). A significant decrease in fibrinogen in patients receiving dexamethasone was seen on POD2 (460.0 vs 530.2). There was an increase in fibrinogen within the dexamethasone cohort at the 2-week visit (535.4 vs 488.9). Post-operative morphine equivalents administered were significantly decreased in patients receiving dexamethasone, but no difference in anti-emetic use was appreciated. CONCLUSION: These data support the hypothesis that the APR following TKA can be attenuated pharmacologically by corticosteroids. Further studies are needed to determine whether the attenuation of the APR with the use of corticosteroids prevents complications following TKA.

Characterizing the Acute Phase Response in Healthy Patients Following Total Joint Arthroplasty: Predictable and Consistent.

BACKGROUND: During surgery, trauma to musculoskeletal tissue induces a systemic reaction known as the acute phase response (APR). When excessive or prolonged, the APR has been implicated as an underlying cause of surgical complications. The purpose of this study was to determine the typical APR following total joint arthroplasty in a healthy population defined by the Charlson Comorbidity Index (CCI). METHODS: This retrospective study identified 180 healthy patients (CCI < 2) who underwent total joint arthroplasty by a single surgeon for primary osteoarthritis from 2013 to 2015. Serial measurements of C-reactive protein (CRP) and fibrinogen were obtained preoperative, perioperative, and at 2 and 6 weeks postoperative. RESULTS: Postoperative CRP peaked during the inpatient period and returned to baseline by 2 weeks. Fibrinogen peaked after CRP and returned to baseline by 6 weeks. Elevated preoperative CRP correlated with a more robust postoperative APR for both total hip arthroplasty and total knee arthroplasty, suggesting that a patient's preoperative inflammatory state correlates with the magnitude of the postoperative APR. CONCLUSION: Measurement of preoperative acute phase reactants may provide an objective means to predict a patient's risk of postoperative dysregulation of the APR and complications.

Practice Management Strategies Among Current Members of the American Association of Hip and Knee Surgeons.

BACKGROUND: A survey was conducted at the 2015 annual meeting of the American Association of Hip and Knee Surgeons (AAHKS) to determine current practice management patterns among AAHKS members. METHODS: A survey was conducted by the session moderator during the annual AAHKS meeting using an audience response system. A series of practice management issues were reviewed with AAHKS members. The survey contained multiple choice and yes and no questions. The audience responses were collected in a central database and then immediately displayed for the audience to review. RESULTS: The survey responses provided interesting data on a variety of topics including: surgeon demographics, surgical activity, practice status, use of physician extenders, sources of ancillary income, the use of electronic medical records and surgeon satisfaction. Interestingly, 51% of AAHKS members remain in private practice and fee for service remains the most common form of compensation (48%). The vast majority of AAHKS members do not perform hip arthroscopy (86%) or hip preservation procedures (87%). CONCLUSION: Valuable information regarding practice patterns of AAHKS members was obtained from this survey. Future surveys will need to focus on 3 areas of activity: surgeon involvement in bundled payment programs frequency of submission of patient data to a joint registry and the frequency of outpatient total joint arthroplasty.

Elevated d-Dimer Is Not Predictive of Symptomatic Deep Venous Thrombosis After Total Joint Arthroplasty.

BACKGROUND: Serum d-dimer is a common screening test for symptomatic deep venous thrombosis (DVT) after total joint arthroplasty. This study characterized the longitudinal resolution of d-dimer measurements after total hip and knee arthroplasty (THA/TKA) over a 6-week period. The authors hypothesized that serum d-dimer would not return to baseline or be below the institutional threshold for a positive test at 6 weeks after uncomplicated total joint arthroplasty, suggesting that quantitative d-dimer has limited clinical utility for postoperative DVT screening. METHODS: An institutional review board-approved retrospective cohort study was conducted with consecutive patients between January 2013 and June 2015. A total of 177 adult patients aged 40-88 years who underwent a primary hip or knee arthroplasty with a Charlson Comorbidity Index <3 were included in the study. Serum d-dimer was measured at preoperative, perioperative, and postoperative 2- and 6-week time points. RESULTS: d-dimer measurements peaked 2 weeks postoperatively for both TKA and THA. At the 6-week time point, the peak serum d-dimer measurement resolved by 54.3% and 76.6% for TKA and THA, respectively. At 6 weeks after operation, 92% of THA patient and 100% of TKA patients had serum d-dimer measurements higher than the institutional threshold (0.40 µg/mL) for a "positive" quantitative test. No symptomatic DVTs were reported for the THA and TKA cohorts during the study period. CONCLUSION: The results suggest that serum d-dimer is an ineffective screening test for the diagnosis of symptomatic DVT in the acute postoperative period. The authors propose that extravascular fibrinolysis, a process essential for wound healing, has a crucial role in the prolonged elevation of serum d-dimer in the postoperative period.

Screening for deep vein thrombosis after periacetabular osteotomy in adult patients: is it necessary?

BACKGROUND: The periacetabular osteotomy has become a common procedure for treating symptomatic acetabular dysplasia. Like other major hip procedures, there is concern regarding the risk of associated venous thromboembolic disease. Nevertheless, there is limited information regarding the need for screening, and optimal prophylactic measures have not been established. QUESTIONS/PURPOSES: We sought to determine the frequency of thromboembolic events (deep vein thrombosis [DVT] and symptomatic pulmonary embolism [PE]) associated with the periacetabular osteotomy in in patients receiving aspirin and mechanical compression prophylaxis. METHODS: We performed a retrospective review of 134 adult patients (149 hips) treated with the periacetabular osteotomy during an 8-year period. During this period, 136 (91%) of the hips treated with a periacetabular osteotomy were screened within 1 week for DVT, whereas 13 (9%) could not be evaluated for various reasons. The mean age of the patients at the time of surgery was 30 years (range, 18-60 years), and no patients were lost to followup during the 4 to 6 months after surgery. The same thromboembolic prophylactic regimen was used for all patients. This consisted of 325 mg aspirin twice a day and compression stockings for 6 weeks and lower extremity pneumatic compression devices while hospitalized. Screening bilateral lower extremity ultrasonography was performed within 1 week (mean, 4 days) of the procedure to detect asymptomatic DVTs. RESULTS: Of the 134 patients, two patients (two hips) with negative postoperative screening ultrasounds presented at 14 and 38 days postoperatively with clinical symptoms of DVT. Repeat ultrasound confirmed this diagnosis in both cases. There were no symptoms of PE. Screening venous ultrasonography did not identify any DVTs during the early postoperative period before discharge. These two patients were treated with 3 to 6 months of warfarin anticoagulation. Neither patient had persistent symptoms related to the DVT. CONCLUSIONS: These data indicate that the risk of symptomatic DVT associated with periacetabular osteotomy is low (1%) with use of aspirin and mechanical compression prophylaxis. Furthermore, routine postoperative screening did not detect any patients with an asymptomatic DVT. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Osteonecrosis of the knee - which joint preservation procedures work?

There is no consensus with respect to the best procedures to preserve the knee joint in patients with osteonecrosis of the knee. We performed a systematic review of the literature between 1999 and 2012. Only 10 of 1057 studies met our inclusion criteria. Core decompression prevented additional surgical treatment in pre-collapse knees with a failure rate of 10.4% (7 of 67 knees). Autogenous and osteochondral grafts decreased the need for additional surgery in both pre-collapse (0%, 20 of 20) and post-collapse knees (10.5%, 8 of 76 knees). Although these results are quite promising multi-center randomized trials are needed to identify the optimal procedures to treat this disease.

Can ChatGPT Answer Patient Questions Regarding Total Knee Arthroplasty?

The internet has introduced many resources frequently accessed by patients prior to orthopaedic visits. Recently, Chat Generative Pre-Trained Transformer, an artificial intelligence-based chat application, has become publicly and freely available. The interface uses deep learning technology to mimic human interaction and provide convincing answers to questions posed by users. With its rapidly expanding usership, it is reasonable to assume that patients will soon use this technology for preoperative education. Therefore, we sought to determine the accuracy of answers to frequently asked questions (FAQs) pertaining to total knee arthroplasty (TKA).Ten FAQs were posed to the chatbot during a single online interaction with no follow-up questions or repetition. All 10 FAQs were analyzed for accuracy using an evidence-based approach. Answers were then rated as "excellent response not requiring clarification," "satisfactory requiring minimal clarification," satisfactory requiring moderate clarification," or "unsatisfactory requiring substantial clarification."Of the 10 answers given by the chatbot, none received an "unsatisfactory" rating with the majority either requiring minimal (5) or moderate (4) clarification. While many answers required nuanced clarification, overall, answers tended to be unbiased and evidence-based, even when presented with controversial subjects.The chatbot does an excellent job of providing basic, evidence-based answers to patient FAQs prior to TKA. These data were presented in a manner that will be easily comprehendible by most patients and may serve as a useful clinical adjunct in the future.

Is pain and dissatisfaction after TKA related to early-grade preoperative osteoarthritis?

BACKGROUND: There is growing evidence to suggest many patients experience pain and dissatisfaction after TKA. The relationship between preoperative osteoarthritis (OA) severity and postoperative pain and dissatisfaction after TKA has not been established. QUESTIONS/PURPOSES: We explored the relationship between early-grade preoperative OA with pain and dissatisfaction after TKA by (1) determining the incidence of early-grade preoperative OA in painful TKAs with no other identifiable abnormality; and (2) comparing this incidence with the incidence of early-grade OA in three other cohorts of patients undergoing TKA. METHODS: We evaluated all (n = 49) painful TKAs in a 1-year period that had no evidence of loosening, instability, malalignment, infection, or extensor mechanism dysfunction and classified the degree of preoperative OA according to the scale of Kellgren and Lawrence. For comparison, we identified three other cohorts of TKAs from the same center and classified their preoperative grade of OA: Group B (n = 100) was a consecutive series of primary TKAs performed for OA during the same year; Group C (n = 80) were asymptomatic TKAs from 1 to 4 years postoperatively; and Group D (n = 80) were TKAs with some degree of pain at 1 to 4 years postoperatively. RESULTS: Patients in Group A had a higher incidence of early-grade OA is preoperatively (49%) compared with any of the comparison groups: Group B, 5%; Group C, 6%; and Group D, 10%. CONCLUSIONS: A high percentage of patients referred for unexplained pain after TKA had early-grade osteoarthritis preoperatively. Patients undergoing TKA for less than Grade 3 or 4 OA should be informed that they may be at higher risk for persistent pain and dissatisfaction.

Disclosure of financial conflicts of interest: an evaluation of orthopaedic surgery patients' understanding.

BACKGROUND: Industry and orthopaedic surgeons often partner to develop new technology, which can lead to orthopaedic surgeons having financial conflicts of interest (FCOI). It is essential these FCOI be conveyed clearly to patients. It is unclear, however, whether and to what degree patients understand the ramifications of physician FCOI. QUESTIONS/PURPOSES: We evaluated (1) patients' concerns regarding their surgeon having FCOI or the presence of institutional FCOI, (2) the effect of surgeon FCOI on patients' willingness to have surgery, and (3) patients' understanding of FCOI. METHODS: We asked 101 patients (66% female) receiving total joint arthroplasty from the orthopaedic practices of two surgeons at an academic health center to complete a descriptive, correlational designed survey at their 6-week followup appointment. The data collected included patient demographics, knowledge of FCOI, and the influence of FCOI on patient attitudes toward surgery and their surgeon. RESULTS: A minority of patients (13%) reported discussing FCOI with prior physicians and only 55% agreed or strongly agreed a surgeon should disclose FCOI. Only 15% of patients believed such conflicts would make them less likely to have their surgeon operate on them. Level of education was weakly correlated (Spearman's rho = 0.29) with patient understanding of FCOI. CONCLUSIONS: Overall, patients had a poor understanding of FCOI. Both level of education and previous discussions of FCOI predicted better understanding. This study emphasizes communication of FCOI with patients needs to be enhanced.

Diagnosis Dilemma, Culture-Negative Periprosthetic Hip Infection Versus Acute Gouty Arthritis: A Case Report.

CASE: We report the case of acute gouty arthritis mimicking infection in a 59-year-old woman who had an extensive history of periprosthetic joint infection (PJI) and multiple revisions. Initial laboratory testing, examination, and recency bias suggested recurrent PJI, but aspiration revealed an acute gout attack without superimposed infection. The patient's examination and serological markers improved off antibiotics, and she subsequently avoided an unnecessary revision surgery. CONCLUSION: Although rare, acute gouty arthritis should be considered in every patient, and complete workup should be performed, regardless of infectious or rheumatologic history.

Assessing ChatGPT Responses to Common Patient Questions Regarding Total Hip Arthroplasty.

BACKGROUND: The contemporary patient has access to numerous resources on common orthopaedic procedures before ever presenting for a clinical evaluation. Recently, artificial intelligence (AI)-driven chatbots have become mainstream, allowing patients to engage with interfaces that supply convincing, human-like responses to prompts. ChatGPT (OpenAI), a recently developed AI-based chat technology, is one such application that has garnered rapid growth in popularity. Given the likelihood that patients may soon call on this technology for preoperative education, we sought to determine whether ChatGPT could appropriately answer frequently asked questions regarding total hip arthroplasty (THA). METHODS: Ten frequently asked questions regarding total hip arthroplasty were posed to the chatbot during a conversation thread, with no follow-up questions or repetition. Each response was analyzed for accuracy with use of an evidence-based approach. Responses were rated as "excellent response not requiring clarification," "satisfactory requiring minimal clarification," "satisfactory requiring moderate clarification," or "unsatisfactory requiring substantial clarification." RESULTS: Of the responses given by the chatbot, only 1 received an "unsatisfactory" rating; 2 did not require any correction, and the majority required either minimal (4 of 10) or moderate (3 of 10) clarification. Although several responses required nuanced clarification, the chatbot's responses were generally unbiased and evidence-based, even for controversial topics. CONCLUSIONS: The chatbot effectively provided evidence-based responses to questions commonly asked by patients prior to THA. The chatbot presented information in a way that most patients would be able to understand. This resource may serve as a valuable clinical tool for patient education and understanding prior to orthopaedic consultation in the future.

Perioperative oxidative stress predicts subsequent pain-related outcomes in the 6 months after total knee arthroplasty.

ABSTRACT: Total knee arthroplasty (TKA) is effective for pain reduction in most patients, but 15% or more report unsatisfactory long-term pain outcomes. We tested whether oxidative stress (OS) related to extended tourniquet application during TKA and subsequent ischemic reperfusion (IR) contributed to adverse post-TKA pain outcomes. Blood samples were obtained in 91 patients with osteoarthritis (63% female) undergoing TKA before tourniquet placement (T1), 45 minutes after tourniquet inflation (T2), and 15 minutes after tourniquet removal (T3). Plasma levels of F 2 -isoprostanes and isofurans, the most specific measures of in vivo OS, were quantified. Pain intensity and function were assessed at baseline and again at 6 weeks and 6 months after TKA. Results indicated that higher Combined OS (F 2 -isoprostanes + isofurans/2) at T1 baseline and larger increases in Combined OS from T1 to T2 were associated with higher baseline-corrected past 24-hour worst and average pain intensity (numeric rating scale) and higher past week McGill Pain Questionnaire-2 total scores at 6-month follow-up ( P 's < 0.05). Increases in Combined OS from T1 to T3, which should most directly capture OS and IR injury related to tourniquet use, were not associated with short-term or long-term post-TKA pain outcomes. Longer ischemia duration was unexpectedly associated with lower baseline-corrected pain intensity at 6-month follow-up. Combined OS was not linked to functional outcomes at either follow-up. Elevated perioperative OS seems to exert small but significant adverse effects on long-term post-TKA pain outcomes, although this OS seems unrelated to IR injury associated with extended tourniquet use.

Dexamethasone Is Associated With a Statistically Significant Increase in Postoperative Blood Glucose Levels Following Primary Total Knee Arthroplasty.

Background: Dexamethasone has the potential to cause a transient increase in blood glucose levels. Recent evidence has suggested the potential for a linearly increased risk of periprosthetic joint infection beginning at blood glucose levels of ≥115 mg/dL and an optimal cutoff of 137 mg/dL. We designed the following study to determine (1) what percentage of our patients had postoperative day 1 (POD1) glucose levels above 137 mg/dL and (2) if the administration of dexamethasone further increased this risk. Methods: All primary total knee arthroplasties performed from 1998 to 2021 at our institution were identified and retrospectively reviewed. Patient demographics, dexamethasone administration, and perioperative glucose levels were recorded. Outcomes included POD1 glucose levels, infection rate, and all-cause reoperations and revisions. Results: The average POD1 glucose level for the entire cohort (n = 5353) was 138.7 mg/dL. The percentage of patients with a glucose level of 137 mg/dL or higher was significantly greater in patients that received dexamethasone (55.2% vs 37.7%; P < .0001). Significantly higher glucose levels were seen with dexamethasone administration in both diabetic (187.7 vs 173.4 mg/dL; P < .0001) and nondiabetic patients (137.7 vs 128.0 mg/dL; P < .0001). Dexamethasone use was associated with a nonstatistically significant increase in infection rates (1.7% vs 1.0%; P = .177). Conclusions: Administration of dexamethasone is associated with a statistically significant increase in POD1 glucose levels, regardless of diabetic status. Dexamethasone use should continue to be closely monitored given the potential risks of elevated postoperative glucose levels and the potential for periprosthetic infection.