Evaluating the affect and reversibility of opioid-induced androgen deficiency in an orthopaedic animal fracture model

Morphine-induced osteolysis and hypersensitivity is mediated through toll-like receptor-4 in a murine model of metastatic breast cancer

ABSTRACT

The propensity for breast cancer to metastasize to bone is coupled to the most common complaint among breast cancer patients: bone pain. Classically, this type of pain is treated using escalating doses of opioids, which lack long-term efficacy due to analgesic tolerance, opioid-induced hypersensitivity, and have recently been linked to enhanced bone loss. To date, the molecular mechanisms underlying these adverse effects have not been fully explored. Using an immunocompetent murine model of metastatic breast cancer, we demonstrated that sustained morphine infusion induced a significant increase in osteolysis and hypersensitivity within the ipsilateral femur through the activation of toll-like receptor-4 (TLR4). Pharmacological blockade with TAK242 (resatorvid) as well as the use of a TLR4 genetic knockout ameliorated the chronic morphine-induced osteolysis and hypersensitivity. Genetic MOR knockout did not mitigate chronic morphine hypersensitivity or bone loss. In vitro studies using RAW264.7 murine macrophages precursor cells demonstrated morphine-enhanced osteoclastogenesis that was inhibited by the TLR4 antagonist. Together, these data indicate that morphine induces osteolysis and hypersensitivity that are mediated, in part, through a TLR4 receptor mechanism.

Perioperative Management of Comorbidities in Spine Surgery

The number of spinal operations performed in the United States has significantly increased in recent years. Along with these rising numbers, there has been a corresponding increase in the number of patient comorbidities. The focus of this article is to review comorbidities in Spine surgery patients and outline strategies to optimize patients and avoid complications.

Opiates Possibly Boosted Human Civilization

: Testosterone is a fundamental biological drive for human survival. Evidence documents an association between the evolutionary suppression of testosterone and the civilization processes, especially their socialization and family colonization abilities, among early humans. Interestingly, opiates suppress testosterone as a side effect. However, in clinical practice, clients undergoing opioid substitution therapy have subnormal, normal, or even above-normal testosterone. This paper discusses a possibility indicating that opiates promoted civilization processes among early humans. We further suggest that modern humans might have inherited the positive impact of opiates on early humans as a biological propensity for using opioids. Some users may use opioids for self-medication to decrease their extraordinarily high testosterone levels.

Clinical Practice Guidelines for Pain Management in Acute Musculoskeletal Injury

PURPOSE

We aimed to produce comprehensive guidelines and recommendations that can be utilized by orthopaedic practices as well as other specialties to improve the management of acute pain following musculoskeletal injury.

METHODS

A panel of 15 members with expertise in orthopaedic trauma, pain management, or both was convened to review the literature and develop recommendations on acute musculoskeletal pain management. The methods described by the Grading of Recommendations Assessment, Development, and Evaluation Working Group were applied to each recommendation. The guideline was submitted to the Orthopaedic Trauma Association (OTA) for review and was approved on October 16, 2018.

RESULTS

We present evidence-based best practice recommendations and pain medication recommendations with the hope that they can be utilized by orthopaedic practices as well as other specialties to improve the management of acute pain following musculoskeletal injury. Recommendations are presented regarding pain management, cognitive strategies, physical strategies, strategies for patients on long term opioids at presentation, and system implementation strategies. We recommend the use of multimodal analgesia, prescribing the lowest effective immediate-release opioid for the shortest period possible, and considering regional anesthesia. We also recommend connecting patients to psychosocial interventions as indicated and considering anxiety reduction strategies such as aromatherapy. Finally, we also recommend physical strategies including ice, elevation, and transcutaneous electrical stimulation. Prescribing for patients on long term opioids at presentation should be limited to one prescriber. Both pain and sedation should be assessed regularly for inpatients with short, validated tools. Finally, the group supports querying the relevant regional and state prescription drug monitoring program, development of clinical decision support, opioid education efforts for prescribers and patients, and implementing a department or organization pain medication prescribing strategy or policy.

CONCLUSIONS

Balancing comfort and patient safety following acute musculoskeletal injury is possible when utilizing a true multimodal approach including cognitive, physical, and pharmaceutical strategies. In this guideline, we attempt to provide practical, evidence-based guidance for clinicians in both the operative and non-operative settings to address acute pain from musculoskeletal injury. We also organized and graded the evidence to both support recommendations and identify gap areas for future research.

Opioids delay healing of spinal fusion: a rabbit posterolateral lumbar fusion model

BACKGROUND CONTEXT

Opioid use is prevalent in the management of pre- and postoperative pain in patients undergoing spinal fusion. There is evidence that opioids downregulate osteoblasts in vitro, and a previous study found that morphine delays the maturation and remodeling of callus in a rat femur fracture model. However, the effect of opioids on healing of spinal fusion has not been investigated before. Isolating the effect of opioid exposure in humans would be limited by the numerous confounding factors that affect fusion healing. Therefore, we have used a well-established rabbit model to study the process of spinal fusion healing that closely mimics humans.

PURPOSE

The objective of this work was to study the effect of systemic opioids on the process of healing of spinal fusion in a rabbit posterolateral spinal fusion model.

STUDY DESIGN/SETTING

This is a preclinical animal study.

MATERIALS AND METHODS

Twenty-four adult New Zealand white rabbits were studied in two groups after approval from the Institutional Animal Care and Use Committee (IACUC). The opioid group (n=12) received 4 weeks' preoperative and 6 weeks' postoperative transdermal fentanyl. Serum fentanyl levels were measured just before surgery and 4 weeks postoperatively to ensure adequate levels. The control group (n=12) received only perioperative pain control as necessary. All animals underwent a bilateral L5-L6 posterolateral spinal fusion using iliac crest autograft. Animals were euthanized at the 6-week postoperative time point, and assessment of fusion was done by manual palpation, plain radiographs, microcomputed tomography (microCT), and histology.

RESULTS

Twelve animals in the control group and 11 animals in the opioid group were available for analysis at the end of 6 weeks. The fusion scores on manual palpation, radiographs, and microCT were not statistically different. Three-dimensional microCT morphometry found that the fusion mass in the opioid group had a lower bone volume (p=.09), a lower trabecular number (p=.02), and a higher trabecular separation (p=.02) compared with the control group. Histologic analysis found areas of incorporation of autograft and unincorporated graft fragments in both groups. In the control group, there was remodeling of de novo woven bone to lamellar organization with incorporation of osteocytes, formation of mature marrow, and relative paucity of hypertrophied osteoblasts lining new bone. Sections from the opioid group showed formation of de novo woven bone, and hypertrophied osteoblasts were seen lining the new bone. There were no sections showing lamellar organization and development of mature marrow elements in the opioid group. Less dense trabeculae on microCT correlated with histologic findings of relatively immature fusion mass in the opioid group.

CONCLUSIONS

Systemic opioids led to an inferior quality fusion mass with delay in maturation and remodeling at 6 weeks in this rabbit spinal fusion model. These preliminary results lay the foundation for further research to investigate underlying cellular mechanisms, the temporal fusion process, and the dose-duration relationship of opioids responsible for our findings.

Comparison of implant survivability in primary 1- to 2-level lumbar fusion amongst opioid abusers and non-opioid abusers

Background

Primary lumbar fusion (LF) is a treatment option for degenerative disc disease. The literature is limited regarding postoperative complications in opioid abusers undergoing LF. The purpose of this study was to compare 2-year short term implant-related complications, infection rates, 90-day readmission rates, in-hospital length of stay, and cost of care amongst opioid abusers (OAS) and non-opioid abusers (NAS) undergoing primary 1- to 2-level primary lumbar fusion (1-2LF).

Methods

A retrospective review was performed using the Medicare Standard Analytical Files from an administrative database. Patients undergoing LF were queried using the International Classification of Disease, ninth revision (ICD-9) procedure codes 81.04-81.08. Patients who underwent 1-2LF were filtered using ICD-9 procedure code 81.62. Inclusion criteria for the study group consisted of patients undergoing primary 1-2LF with a diagnosis of opioid abuse and dependency 90-day prior to the procedure. NAS undergoing 1-2LF served as controls. Patients in the study group were matched to controls according to age, gender, and Charlson-Comorbidity Index (CCI). Two mutually exclusive cohorts were formed and outcome measures analyzed and compared were implant complications, infection rates, 90-day readmission rates, LOS, and cost of care.

Results

After the matching process 13,342 patients were identified with equal cohort distribution. OAS had higher odds implant related complications (OR: 2.78, P<0.001) such as prosthetic joint dislocation (OR: 3.83, P<0.001), requiring revision (OR: 2.89, P<0.001), pseudarthrosis (OR: 2.50, P<0.001), and spine related infections (OR: 1.58, P<0.001) compared to NAS. OAS had higher 90-day readmission rates, (OR: 1.29, P<0.001), higher hospital costs ($143,057.38 vs. $121,450.45, P<0.001), and greater in-hospital LOS (P<0.001).

Conclusions

OAS are susceptible to complications following primary 1-2LF. Appropriate patient counseling regarding the effects of opioids on lumbar fusion should be given priority to maximize patient outcomes. Future studies should investigate the impact of pre-operative opioid abuse versus post-operative opioid use.

Postoperative opioids, endocrine changes, and immunosuppression

Opioids are among most effective drugs for managing acute postoperative pain. This article discusses the potential effects of perioperative opioids on endocrine and immune function.

Leading the Way to Solutions to the Opioid Epidemic: AOA Critical Issues

BACKGROUND

In the past 2 decades, overdoses and deaths from prescription opioids have reached epidemic proportions in the United States. The widespread use of opioids complicates management of the orthopaedic surgery patient in the acute and chronic settings. Orthopaedic surgeons are some of the top prescribers of opioids in the complex setting of chronic use, abuse, and diversion.

METHODS

The literature regarding the basic science of pharmacologic options for pain management (e.g., opioids and nonsteroidal anti-inflammatory drugs), the impact of strategies on bone and soft-tissue healing, and pain relief are summarized as they relate to the management of orthopaedic injuries and conditions. Additionally, a section on designing solutions to address the current opioid crisis is presented.

RESULTS

The mechanism of action of different classes of analgesic medications is discussed, as well as the basic scientific evidence regarding the impact of narcotic and nonnarcotic analgesic medications on bone-healing and on other organ systems. Differences between pain and nociception, various treatment strategies, and clinical comparisons of the effectiveness of various analgesics compared with opioids are summarized. Finally, options for addressing the opioid crisis, including the description of a large system-wide intervention to impact prescriber behavior at the point of care using health-information solutions, are presented.

CONCLUSIONS

Orthopaedic leaders, armed with information and strategies, can help lead the way to solutions to the opioid epidemic in their respective communities, institutions, and subspecialty societies. Through leadership and education, orthopaedic surgeons can help shape the solution for this critical public health issue.

The Effect of Opioids, Alcohol, and Nonsteroidal Anti-inflammatory Drugs on Fracture Union

The estimated rate of fracture nonunion is between 5% and 10%, adding significant cost to the health care system. The cause of fracture nonunion is multifactorial, including the severity of the injury, patient factors resulting in aberrancies in the biology of fracture, and the side effects of pain control modalities. Minimizing surgeon-controlled factors causing nonunion is important to reduce the cost of health care and improve patient outcomes. Opioids, alcohol, and nonsteroidal anti-inflammatory drugs have been implicated as risk factors for fracture nonunion. Current literature was reviewed to examine the effects of opioids, alcohol, and nonsteroidal anti-inflammatory drugs on fracture union.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.