Moderating effects of preoperative knee pain and pain catastrophizing on the relation between COMT rs4680 genotypes and chronic postsurgical pain in total knee arthroplasty patients.

BACKGROUND: The Catechol-O-methyltransferase (COMT) gene, responsible for encoding an enzyme crucial in the metabolism of catecholamines, is known to play a significant role in pain perception. Polymorphisms within this gene, particularly the COMT rs4680 genotypes, have been linked to various acute pain phenotypes. This prospective cohort study examines interactions among the genetic polymorphism COMT rs4680 genotypes, preoperative knee pain, and pain catastrophizing in chronic postsurgical pain (CPSP) at 3, 6, and 12 months post-total knee arthroplasty (TKA). STUDY DESIGN: A total of 280 patients undergoing primary unilateral TKA participated, sharing demographic details, preoperative knee pain levels, psychological variables (pain catastrophizing), and COMT rs4680 genotyping via venous blood samples. Telephone interviews at specified intervals enabled the application of binary logistic regressions and interaction models. RESULTS: Significant influences of preoperative knee pain and pain catastrophizing on postsurgical outcomes were observed. Specifically, at the first time point (T1, 3 months post-TKA), a notable moderation effect was identified in preoperative knee pain (R2 change = 0.026, p = 0.026). The Johnson-Neyman regions of significance (RoS) indicated these moderation effects were significant above a threshold of 17.18 (p = 0.05), accounting for 26.4%. At the third time point (T3, 12 months post-TKA), a complex three-way interaction among genotypes (GG, GA, and AA carriers) was evident, resulting in an R2 change of 0.051 (p = 0.009). Here, the RoS for pain catastrophizing was above 32.74 for 30.5% of GG genotype carriers, above 22.38 for 50.8% of GA carriers, and below 11.94 for 63.2% of AA carriers. CONCLUSION: This study illuminates the significant role of the COMT Val158Met rs4680 polymorphism in susceptibility to prolonged pain following TKA. It also elucidates how these genetic genotypes interplay with preoperative knee pain and pain catastrophizing. Such intricate genetic-psychological-pain relationships necessitate additional investigation to confirm these findings and potentially guide post-TKA pain management strategies.

Risk factors analysis and nomogram construction for postoperative pulmonary infection in elderly patients with hip fractures.

PURPOSE: The purpose of this study was to predict the probability of postoperative pulmonary infection in elderly patients with hip fractures by developing and validating a precise model. METHODS: The clinical data of 1008 elderly hip fracture patients undergoing surgical treatment in Shanghai Tenth Peoples' Hospital were retrospectively selected. A univariate analysis and multivariate regression were used to analyze the independent risk factors for postoperative pulmonary infection in elderly patients with hip fractures. A risk prediction model was established, and a nomogram was drawn. The area under the ROC curve and Hosmer‒Lemeshow test were used to evaluate the predictive effect of the model. RESULTS: The multivariate regression analysis indicated that age > 73, time from fracture to surgery (d) > 4 days, smoking, ASA ≥ III level, COPD, hypoproteinemia, red cell distribution width > 14.8%, mechanical ventilation time > 180 min, and stay in the ICU were independent risk factors for postoperative pulmonary infection in elderly patients. The AUCs of the model were 0.891 and 0.881, 0.843, respectively, in the two verification groups. For the Hosmer‒Lemeshow test, the P values were 0.726 in the modeling group and 0.497 and 0.231 in the verification group (P > 0.05). CONCLUSION: Overall, this study uncovered different independent risk factors for postoperative pulmonary infection in patients with hip fractures. The nomogram can effectively predict the occurrence of postoperative pulmonary infection.

Prevalence and Predictors of Chronic Pain with Two-Year Follow-Up After Knee Arthroplasty.

Background: Pain relief is the most important issue in the long-term outcome of arthroplasty surgery, with nearly one-third of patients still suffered persistent pain and caused dissatisfaction after the surgery. Methods: A total of 713 patients underwent primary elective primary TKA and UKA were included consecutively between July 2018 and December 2019, using binary logistic method to analyze the data. Results: The prevalence of CPSP at rest and on movement at 2-year was 12.1% and 37.7% respectively after primary knee arthroplasty and CPSP at rest factors included: age above 80 (odds ratio [OR]= 6.72, 95% confidence interval [CI] 1.58 to 28.56), BMI above 30 (2.339, 1.02 to 5.383), and moderate to severe pain variables: preoperative pain, (1.95, 1.11 to 3.41); APSP on movement, 4.9 (2.31-10.6); and follow-up contralateral knee pain-at-rest scores (12.6, 5.5 to 28.5). Factors associated with presence of CPSP on movement included: no smoking (2.59, 1.07 to 6.26); and moderate to severe pain variables: preoperative pain, (1.57, 1.073 to 2.30); APSP at rest, (1.85, 1.13 to 3.02); APSP on movement, 6.11 (3.82 to 9.78); and follow-up contralateral knee pain-on-movement scores, 3.22 (2.08 to 5.00). Factors to occurrence of moderate to severe CPSP on movement include: presence of COPD (12.20, 2.19 to 67.98); and moderate to severe pain variables: preoperative pain (2.36, 1.32 to 4.23); APSP on movement (4.68, 1.95 to 11.25); and follow-up contralateral knee pain-on-movement scores (2.71, 1.66 to 4.42). Conclusion: Prevention strategies should be targeted to different types of pain, and the comorbidity of COPD undergoing knee arthroplasty should receive early identification and attention.