The Perioperative Continuation of Aspirin in Patients Undergoing Arthroscopic Surgery of the Knee

Venous Thromboembolism Chemoprophylaxis in Knee Arthroscopy: A Break-Even Analysis of Cost

BACKGROUND

Symptomatic venous thromboembolism (VTE) is a serious and costly complication after knee arthroscopy. There continues to be debate regarding the use of VTE prophylaxis after knee arthroscopy, and minimal research has explored its cost-effectiveness.

HYPOTHESIS

Both aspirin and enoxaparin would be cost-effective in preventing symptomatic VTE.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 3.

METHODS

The literature was searched and the TriNetX research database was queried to determine a range of initial rates of VTE. An open-access retail database was used to determine the mean retail price for aspirin (325 mg) and enoxaparin (30 mg and 40 mg). Our institutional records were used to determine the cost of treating VTE. A "break-even" analysis was then performed to determine the absolute risk reduction necessary to make these drugs cost-effective. This value was then used to calculate the number of patients who would need to be treated (NNT) to prevent a single VTE while still breaking even on cost.

RESULTS

The cost of treating VTE was $9407 (US Dollars). Aspirin (325 mg), enoxaparin (30 mg), and enoxaparin (40 mg) were found to cost $1.86, $188.72, and $99.99, respectively. The low, TriNetX, and high rates of VTE were 0.34%, 0.86%, and 10.9%, respectively. Aspirin was cost-effective at all 3 rates if the initial rate decreased by 0.02% (NNT = 5058). Both formulations of enoxaparin were cost-effective at the high initial rate if they decreased by 2.01% (NNT = 50) and 1.06% (NNT = 94), respectively. However, at the low and TriNetX rates, the 2 doses of enoxaparin were not cost-effective because their final break-even rate exceeded the initial VTE rate.

CONCLUSION

Aspirin and, in some cases, enoxaparin are cost-effective treatments for VTE prophylaxis after knee arthroscopy.

Patients receiving knee arthroplasty with pre-existing long-term aspirin use suffer lower risk of perioperative complications but feel more postoperative pain

BACKGROUND

Aspirin has gained increasing use-popularity on account of its multiple benefits. The present study aimed to investigate how a pre-existing long-term aspirin use (L-AU) would affect perioperative complications and postoperative pain in primary total knee arthroplasty (TKA) patients.

METHODS

Utilizing the National Inpatient Sample (NIS) database, primary TKAs were divided into L-AU and non-L-AU cohorts. Propensity score matching (PSM) was performed to match the demographics and comorbidities characteristics. Chi-square test and logistic regression analysis were calculated for the risk analysis of perioperative complications and postoperative pain.

RESULTS

The popularity of L-AU in primary TKA patients had significantly increased from 1.5% (2005) to 10.5% (2014) in the U.S. Pre-existing L-AU was associated with decreased risks of most perioperative complications (any complication, adjusted odds ratio [aOR]: 0.920), in-hospital mortality (aOR: 0.367), and shortened hospitalization stay (LOS) (aOR: 0.647), etc. However, L-AU was recognized as a risk factor of acute postoperative pain (aOR: 1.466) and slightly higher total cost (aOR: 1.047).

CONCLUSIONS

For the first time in the present study, it is found that pre-existing long-term aspirin use is benefic in reducing perioperative complication risk. According to this finding, future research might determine the optimal pre-operational taking time and dose of aspirin use. Consequently, orthopedic surgeons and healthcare providers could provide this valuable advice to specific patients prior to a planned arthroplasty and subsequently gain feasible clinical benefits.

Renal insufficiency plays a crucial association factor in severe knee osteoarthritis-induced pain in patients with total knee replacement: A retrospective study

Pain, the main symptom of osteoarthritis (OA), can lead to functional disability in patients with knee OA. Understanding the association factors related to knee pain is important since preventing OA-induced disabilities can be achieved by modifying these pain-associated issues. Therefore, this study was aimed to investigate the association factors for OA-induced knee pain in Taiwanese patients who received total knee replacements (TKR).In this retrospective study, 357 subjects who had undergone TKR at the Taipei Municipal Wan-Fang Hospital were recruited. The distribution of pain severity among patients with knee OA was evaluated. Demographic data and clinical parameters were analyzed to determine relationships between these variables and the severity of knee OA pain.Of the 357 patients studied, 54% and 33% had moderate and severe knee pain, respectively. Furthermore, a multivariate logistic regression analysis revealed that serum creatinine (>1.5 mg/dL) and an estimated glomerular filtration rate (eGFR) (<60 mL/min/1.73 m) were significantly associated with severe knee pain in OA patients. A significant correlation between severe knee pain and serum creatinine or eGFR was demonstrated by Pearson correlations.Taken together, the renal insufficiency defined by an elevated serum creatinine or a low eGFR in OA patients who required TKR was associated with severe knee pain. These variables must be considered while treating knee OA pain, especially in those patients with severe pain.