Can morphine interfere in the healing process during chronic stress?

Implant-Related Complications Among Patients With Opioid Use Disorder Following Primary Total Hip Arthroplasty: A Matched-Control Analysis of 42,097 Medicare Patients

BACKGROUND

Opioid use disorders (OUD) are a major cause of morbidity and mortality. The authors of this study hypothesize that patients who have an OUD will have greater relative risk of implant-related complications, periprosthetic joint infections (PJIs), readmission rates, and will incur greater costs compared to non-opioid use disorder (NUD) patients following primary total hip arthroplasty (THA).

METHODS

OUD patients who underwent a THA between 2005 and 2014 were identified and matched to controls in a 1:5 ratio according to age, sex, a comorbidity index, and various medical comorbidities yielding 42,097 patients equally distributed in both cohorts. Pearson's chi-square analyses were used to compare patient demographics. Relative risk (RR) was used to analyze and compare risk of 2-year implant-related complications, 90-day PJIs, and 90-day readmission rates. Welch's t-tests were used to compare day of surgery and 90-day episode-of-care costs between the cohorts. A P value less than .006 was considered statistically significant.

RESULTS

OUD patients had higher incidences and risks of implant-related complications (11.99% vs 6.68%; RR, 1.74; P < .001), developing PJIs within 90 days (2.38% vs 1.81%; RR, 1.32; P = .001), and 90-day readmissions (21.49% vs 17.35%; RR, 1.23; P < .001). Additionally, the study demonstrated OUD patients incurred greater day of surgery ($14,384.30 vs $13,150.12, P < .0001) and 90-day costs ($21,183.82 vs $18,709.02, P < .0001) compared to controls.

CONCLUSION

After controlling for age, sex, a comorbidity index, and various medical complications, OUD patients are at greater risk to experience implant-related complications, PJIs, readmissions, and have greater costs following primary THA compared to non-OUD patients. This study should help orthopedic surgeons counsel their patients of potential complications which may arise following their primary THA.

Reduced opioid requirements following unicompartmental knee arthroplasty compared with total knee arthroplasty

Aims

Unicompartmental knee arthroplasty (UKA) provides improved early functional outcomes and less postoperative morbidity and pain compared with total knee arthroplasty (TKA). Opioid prescribing has increased in the last two decades, and recently states in the USA have developed online Prescription Drug Monitoring Programs to prevent overprescribing of controlled substances. This study evaluates differences in opioid requirements between patients undergoing TKA and UKA.

Patients and Methods

We retrospectively reviewed 676 consecutive TKAs and 241 UKAs. Opioid prescriptions in morphine milligram equivalents (MMEs), sedatives, benzodiazepines, and stimulants were collected from State Controlled Substance Monitoring websites six months before and nine months after the initial procedures. Bivariate and multivariate analysis were performed for patients who had a second prescription and continued use.

Results

Patients undergoing UKA had a second opioid prescription filled 50.2% of the time, compared with 60.5% for TKA (p = 0.006). After controlling for potential confounders, patients undergoing UKA were still less likely to require a second prescription than those undergoing TKA (adjusted odds ratio (OR) 0.58, 95% confidence interval (CI) 0.42 to 0.81; p = 0.001). Continued opioid use requiring more than five prescriptions occurred in 13.7% of those undergoing TKA and 5.8% for those undergoing UKA (p = 0.001), and was also reduced in UKA patients compared with TKA patients (adjusted OR 0.33, 95% CI 0.16 to 0.67; p = 0.022) in multivariate analysis. The continued use of opioids after six months was 11.8% in those undergoing TKA and 8.3% in those undergoing UKA (p = 0.149). The multivariate models for second prescriptions, continued use with more than five, and continued use beyond six months yielded concordance scores of 0.70, 0.86, and 0.83, respectively.

Conclusion

Compared with TKA, patients undergoing UKA are less likely to require a second opioid prescription and use significantly fewer opioid prescriptions. Thus, orthopaedic surgeons should adjust their patterns of prescription and educate patients about the reduced expected analgesic requirements after UKA compared with TKA. Cite this article: Bone Joint J 2019;101-B(7 Supple C):22–27

Preoperative Opioids Increase the Risk of Periprosthetic Joint Infection After Total Joint Arthroplasty

BACKGROUND

Opioids have well-known immunosuppressive properties and preoperative opioid consumption is relatively common among patients undergoing total joint arthroplasty (TJA). The hypothesis of this study was that utilization of opioids preoperatively would increase the incidence of subsequent periprosthetic joint infection (PJI) in patients undergoing primary TJA.

METHODS

A comparative cohort study design was set up that used a cohort of 23,754 TJA patients at a single institution. Patient records were reviewed to extract relevant information, in particular details of opioid consumption, and an internal institutional database of PJI was cross-referenced against the cohort to identify patients who developed a PJI within 2 years of index arthroplasty. Univariate and multivariate linear regression analyses were used to examine the potential association between preoperative opioid consumption and the development of PJI.

RESULTS

Among the total cohort of 23,754 patients, 5051 (21.3%) patients used opioids before index arthroplasty. Preoperative opioid usage overall was found to be a significant risk factor for development of PJI in the univariate (odds ratio, 1.63; P = .005) and multivariate analyses (adjusted odds ratio, 1.53 [95% confidence interval, 1.14-2.05], P = .005).

CONCLUSION

Preoperative opioid consumption is independently associated with a higher risk of developing a PJI after primary TJA. These findings underscore a need for caution when prescribing opioids in patients with degenerative joint disease who may later require arthroplasty.

Gut Homeostasis, Microbial Dysbiosis, and Opioids

Gut homeostasis plays an important role in maintaining animal and human health. The disruption of gut homeostasis has been shown to be associated with multiple diseases. The mutually beneficial relationship between the gut microbiota and the host has been demonstrated to maintain homeostasis of the mucosal immunity and preserve the integrity of the gut epithelial barrier. Currently, rapid progress in the understanding of the host-microbial interaction has redefined toxicological pathology of opioids and their pharmacokinetics. However, it is unclear how opioids modulate the gut microbiome and metabolome. Our study, showing opioid modulation of gut homeostasis in mice, suggests that medical interventions to ameliorate the consequences of drug use/abuse will provide potential therapeutic and diagnostic strategies for opioid-modulated intestinal infections. The study of morphine's modulation of the gut microbiome and metabolome will shed light on the toxicological pathology of opioids and its role in the susceptibility to infectious diseases.

Effects of drugs of abuse on the central neuropeptide Y system

Neuropeptide Y (NPY), which is widely expressed in the central nervous system is involved in several neuropathologies including addiction. Here we comprehensively and systematically review alterations on the central NPY system induced by several drugs. We report on the effects of psychostimulants [cocaine, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and nicotine], ethanol, and opioids on NPY protein levels and expression of different NPY receptors. Overall, expression and function of NPY and its receptors are changed under conditions of drug exposure, thus affecting several physiologic behaviors, such as feeding, stress and anxiety. Drugs of abuse differentially affect the components of the NPY system. For example methamphetamine and nicotine lead to a consistent increase in NPY mRNA and protein levels in different brain sites whereas ethanol and opioids decrease NPY mRNA and protein expression. Drug-induced alterations on the different NPY receptors show more complex regulation pattern. Manipulation of the NPY system can have opposing effects on reinforcing and addictive properties of drugs of abuse. NPY can produce pro-addictive effects (nicotine and heroin), but can also exert inhibitory effects on addictive behavior (AMPH, ethanol). Furthermore, NPY can act as a neuroprotective agent in chronically methamphetamine and MDMA-treated rodents. In conclusion, manipulation of the NPY system seems to be a potential target to counteract neural alterations, addiction-related behaviors and cognitive deficits induced by these drugs.