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

The Inhibitory Effect of NSAIDs and Opioids on Spinal Fusion: An Animal Model

STUDY DESIGN

Translational research.

OBJECTIVE

To evaluate the relative effects of NSAIDs, opioids, and a combination of the two on spinal fusion inhibition in a rodent model.

SUMMARY OF BACKGROUND DATA

Nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are common postoperative analgesic agents. Since NSAIDs inhibit the cyclooxygenase (COX) pathway, they are seldom prescribed following spinal fusion. Opioids may be given instead, but recent evidence suggests opioids also adversely affect spinal fusion quality and success.

METHODS

Eighty male Sprague-Dawley rats underwent L4-5 posterior lumbar fusion and were given one of the following analgesia regimens: saline, morphine (6 mg/kg), ketorolac (4 mg/kg), or morphine (3 mg/kg) and ketorolac (2 mg/kg). Serum samples were drawn to evaluate systemic pro-osteoblastic cytokines and vascular endothelial growth factor-A (VEGF-A) levels, which were measured through enzyme-linked immunosorbent assays (ELISA). After six weeks, the rats were sacrificed, and the operated spinal segments underwent manual palpation, microCT, and histologic analysis.

RESULTS

Manual palpation scores were significantly diminished in the opioid, NSAID, and multimodal groups when compared with control ( P <0.001). MicroCT fusion scores ( P <0.001) and fusion rates (control: 75% vs . NSAID: 35% vs . opioid: 0% vs . combination: 15%, P <0.001) were significantly diminished in the treatment groups. The bone volume (BV) to tissue volume (TV) ratio (BV/TV) ( P <0.001) and bone mineral density (BMD) ( P <0.001) were all lower in the treatment groups, with the opioid and combined groups having the lowest BMD. Although statistically insignificant ( P <0.09), the concentration of VEGF-A was greater in the control group compared with opioids, NSAIDs, and the combined group.

CONCLUSION

Opioids and NSAIDs, both independently and combined, inhibited spinal fusion and caused inferior bony callus. Administration of opioids resulted in the lowest rate of spinal fusion. We propose this may be due to the inhibition of VEGF-A, which limits angiogenesis to the burgeoning fusion mass.

Predictive factors of symptomatic lumbar pseudoarthrosis following multilevel primary lumbar fusion

Background

Lumbar spinal fusion surgery is a well-established treatment for various spinal disorders. However, one of its complications, pseudoarthrosis, poses a significant concern. This study aims to explore the incidence, time and predictive factors contributing to pseudoarthrosis in patients who have undergone lumbar fusion surgery over a 10-year period.

Methods

Data for this research was sourced from the PearlDiver database where insurance claims of patients who underwent multilevel lumbar spinal fusion between 01/01/2010 and 10/31/2022 were examined for claims of pseudoarthrosis within the 10 years of their index procedure. A variety of demographic, comorbid, and surgical factors were assessed, including age, gender, Elixhauser Comorbidity Index (ECI), surgical approach, substance use disorders and history of spinal disorders. Statistical analyses, including chi-squared tests, multivariate analysis, and cox survival analysis were employed to determine significant associations.

Results

Among the 76,337 patients included in this retrospective study, 2.70% were diagnosed with symptomatic lumbar pseudoarthrosis at an average of 7.38 years in a 10-year follow-up. Multivariate and Cox hazard analyses revealed that significant predictors of symptomatic pseudoarthrosis development following multilevel primary lumbar fusion include vitamin D deficiency, osteoarthritis, opioid and NSAID use, tobacco use, and a prior history of congenital spine disorders.

Conclusions

In summary, this study revealed a 2.70% incidence of symptomatic lumbar pseudoarthrosis within 10 years of the index procedure. It highlighted several potential predictive factors, including comorbidities, surgical approaches, and substance use disorders, associated with the development of symptomatic pseudoarthrosis. Future research should focus on refining our understanding of these factors to improve patient outcomes and optimize healthcare resource allocation.

Opioid Use Increases the Rate of Pseudarthrosis and Revision Surgery in Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective Cohort.

OBJECTIVES

To (1) quantify the risk opioids impart on pseudarthrosis development, (2) analyze the effect of pseudarthrosis on clinical outcomes, and (3) identify if the amount of opioids prescribed are predictive of pseudarthrosis revision.

METHODS

Patients who underwent ACDF at a single institution between 2017-2019 were retrospectively identified. Postoperative dynamic cervical spine radiographs were reviewed to assess fusion status. Logistic regression models measured the effect of morphine milligram equivalents (MME) prescribed on the likelihood of pseudarthrosis development. Receiver operating characteristic (ROC) curves were generated to predict the probability of surgical revision based on MME prescribed.

RESULTS

Of 298 included patients, an average of 2.01 ± 0.82 levels were included in the construct and 121 (40.9%) patients were diagnosed with a pseudarthrosis. However, only 14 (4.7%) required a pseudarthrosis revision. Patients requiring pseudarthrosis revision had worse one-year postoperative Δ PCS-12 (-1.70 vs. 7.58, P = 0.004), Δ NDI (3.33 vs. -15.26, P = 0.002), and Δ VAS Arm (2.33 vs. -2.48, P = .047). Multivariate logistic regression analyses found the three-month postoperative (OR=1.00, P = .010), one-year postoperative (OR=1.001, P = 0.025), and combined pre- and postoperative MME (OR=1.000, P = .035) increased the risk of pseudarthrosis. ROC analysis identified cutoff values to predict pseudarthrosis revision at 90.00 (area under the curve (AUC): 0.693, confidence interval (CI): 0.554-0.832), 132.86 (0.710, CI: 0.589-0.840), 224.76 (0.687, CI: 0.558-0.817) and 285.00 (0.711, CI: 0.585-0.837) MME in the preoperative, three-month postoperative, one-year postoperative, and combined pre-and postoperative period.

CONCLUSION

Increased prescription of opioid medications following ACDF procedures may increase the risk of pseudarthrosis development and revision surgery.

LEVEL OF EVIDENCE

Therapeutic Level III.

Cannabidiol and Cannabigerol, Nonpsychotropic Cannabinoids, as Analgesics that Effectively Manage Bone Fracture Pain and Promote Healing in Mice

Bone fractures are among the most prevalent musculoskeletal injuries, and pain management is an essential part of fracture treatment. Fractures heal through an early inflammatory phase, followed by repair and remodeling. Nonsteroidal anti-inflammatory drugs (NSAIDs) are not recommended for fracture pain control as they potently inhibit the inflammatory phase and, thus, impair the healing. Opioids do not provide a better alternative for several reasons, including abuse potential. Accordingly, there is an unmet clinical need for analgesics that effectively ameliorate postfracture pain without impeding the healing. Here, we investigated the analgesic efficacy of two nonpsychotropic cannabinoids, cannabidiol (CBD) and cannabigerol (CBG), in a mouse model for tibial fracture. Mice with fractured tibiae exhibited increased sensitivity to mechanical, cold, and hot stimuli. Both CBD and CBG normalized pain sensitivity to all tested stimuli, and their analgesic effects were comparable to those of the NSAIDs. Interestingly, CBD and CBG promoted bone healing via multiple mechanisms during the early and late phases. During the early inflammatory phase, both cannabinoids increased the abundance of periosteal bone progenitors in the healing hematoma and promoted the osteogenic commitment of these progenitors. During the later phases of healing, CBD and CBG accelerated the fibrocartilaginous callus mineralization and enhanced the viability and proliferation of bone and bone-marrow cells. These effects culminated in higher bone volume fraction, higher bone mineral density, and improved mechanical quality of the newly formed bone. Together, our data suggest CBD and CBG as therapeutic agents that can replace NSAIDs in managing postfracture pain as both cannabinoids exert potent analgesic effects and, at the same time, promote bone healing. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Chronic Opioid Use Prior to ACDF Surgery Is Associated with Inferior Postoperative Outcomes: A Propensity-Matched Study of 17,443 Chronic Opioid Users

OBJECTIVE

Candidates for anterior cervical discectomy and fusion (ACDF) have a higher rate of opioid use than does the public, but studies on preoperative opioid use have not been conducted. We aimed to understand how preoperative opioid use affects post-ACDF outcomes.

METHODS

The MarketScan Database was queried from 2007 to 2015 to identify adult patients who underwent an ACDF. Patients were classified into separate cohorts based on the number of separate opioid prescriptions in the year before their ACDF. Ninety-day postoperative complications, postoperative readmission, reoperation, and total inpatient costs were compared between opioid strata. Propensity score-matched patient cohorts were calculated to balance comorbidities across groups.

RESULTS

Of 81,671 ACDF patients, 31,312 (38.3%) were nonusers, 30,302 (37.1%) were mild users, and 20,057 (24.6%) were chronic users. Chronic opioid users had a higher comorbidity burden, on average, than patients with less frequent opioid use (P < 0.001). Chronic opioid users had higher rates of postoperative complications (9.1%) than mild opioid users (6.0%) and nonusers (5.3%) (P < 0.001) and higher rates of readmission and reoperation. After balancing opioid nonusers versus chronic opioid users along with demographic characteristics, preoperative comorbidity, and operative characteristics, postoperative complications remained elevated for chronic opioid users relative to opioid nonusers (8.6% vs. 5.7%; P < 0.001), as did rates of readmission and reoperation.

CONCLUSIONS

Chronic opioid users had more comorbidities than opioid nonusers and mild opioid users, longer hospitalizations, and higher rates of postoperative complication, readmission, and reoperation. After balancing patients across covariates, the outcome differences persisted, suggesting a durable association between preoperative opioid use and negative postoperative outcomes.

Preoperative opioids before adult spinal deformity surgery associated with increased reoperations and high rates of chronic postoperative opioid use at 3-year follow-up

PURPOSE

To determine the association of preoperative opioid prescriptions with reoperations and postoperative opioid prescriptions after adult spina deformity (ASD) surgery. With the current opioid crisis, patients undergoing surgery for ASD are at particular risk for opioid-related complications due to significant preoperative disability and surgical morbidity. No previous studies consider preoperative opioids in this population.

METHODS

A retrospective cohort study of patients undergoing posterior spinal fusion (7 or more levels) for ASD was performed. All patients had at least 3 years of postoperative follow-up 3 years postoperatively. Prescriptions for 4 different opioid medications (hydromorphone, oxycodone, hydrocodone, and tramadol) were identified within 3 months preoperatively and up to 3 years postoperatively. Multivariate regression was utilized to determine the association of preoperative use with reoperations and with postoperative opioid use, controlling for both patient and surgery-related confounding factors.

RESULTS

A total of 743 patients were identified and 59.6% (443) had opioid prescriptions within 3 months preoperatively. Postoperative opioid prescriptions were identified in 66.9% of patients at 12 months postoperatively, and in 54.8% at 36 months postoperatively. The 3-year reoperation rate was 11.0% in patients without preoperative prescriptions, 16.0% in patients with preoperative any opioid prescriptions (P = 0.07), and 34.8% in patients with preoperative hydromorphone prescriptions (P < 0.01). In multivariate analysis, preoperative opioid prescriptions were associated with increased reoperations (odds ratio [OR]: 1.62, P = 0.04), and chronic postoperative opioid use (OR: 4.40, P < 0.01). Preoperative hydromorphone prescriptions had the strongest association with both reoperations (OR: 4.96; P < 0.01) and chronic use (OR: 5.19: P = 0.03).

CONCLUSION

In the ASD population, preoperative opioids are associated with both reoperations and chronic opioid use, with hydromorphone having the strongest association. Further investigation of the benefits of preoperative weaning programs is warranted.

Negative pharmacological effect on spine fusion: A narrative review of the literature of evidence-based treatment

Spine fusion surgery is commonly performed for diverse indications, the most frequent one being degenerative spine diseases. Despite the growing importance of this surgery, there is limited evidence concerning the effects of drugs on the process of spine fusion and healing. While asymptomatic sometimes, nonunion of the spine can have tremendous repercussions on the patients' quality of life and the healthcare system rendering it an "expensive complication". This literature review identifies the role of some perioperative drugs in spine fusion and reveals their potential role in pseudarthrosis of the spine. This review also benefits spine surgeons looking for current evidence-based practices. We reviewed the data related to nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, vancomycin, bisphosphonates, proton pump inhibitors (PPIs), pregabalin, and opioids. From the available experimental and clinical studies, we conclude that bisphosphonates might positively influence the process of spine fusion, while steroids and vancomycin have shown variable effects, and the remaining medications likely disturb healing and union of the spine. We recommend spine surgeons be cautious about the drugs they resort to in the critical perioperative period until further clinical studies prove which drugs are safe to be used.

The Effect of Nonsteroidal Anti-inflammatory Drugs and Selective COX-2 Inhibitors on Bone Healing

A recently published study, "Risk of Nonunion With Nonselective NSAIDs, COX-2 Inhibitors, and Opioids" by George et al (J Bone Joint Surg Am. 2020;102:1230-1238), assesses whether the use of nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), selective cyclooxygenase 2 (COX-2) enzyme inhibitors, or opioids was associated with a risk of long bone fracture nonunion in Optum's deidentified private health database. This review analyzes the study, including strengths, weaknesses, and areas for future research. The study found an association between COX-2 inhibitor and opioid use with fracture nonunion but not with nonselective NSAID use. Although the literature on this topic is varied, these results are at least partially aligned with several animal studies that show COX-2 inhibitors to be associated with fracture nonunion. The George et al study design has several important limitations, indicating that further research is needed on this topic.

Association of Duration of Preoperative Opioid Use with Reoperation After One-level Anterior Cervical Discectomy and Fusion in Nonmyelopathic Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to determine that rates of preoperative opioid use in patients undergoing single-level anterior discectomy and fusion (ACDF) without myelopathy and determine the association with reoperations over 5 years.

SUMMARY OF BACKGROUND DATA

Preoperative opioid use before cervical spine surgery has been linked to worse postoperative outcomes. However, no studies have determined the association of duration and type of opioid used with reoperations after ACDF.

METHODS

Patients undergoing single-level ACDF without myelopathy between 2007 and 2016 with at least 5-year follow-up were identified in one private insurance administrative database. Preoperative opiate use was divided into acute (within 3 months), subacute (acute use and use between 3 and 6 months), and chronic (subacute use and use before 6 months) and by the opiate medication prescribed (tramadol, oxycodone, and hydrocodone). Postoperative rates of additional cervical spine surgery were determined at 5 years and multivariate logistic regression was used to determine the association of preoperative opiates with additional surgery.

RESULTS

Of 445 patients undergoing single-level ACDF without myelopathy, 66.3% were taking opioid medications before surgery. The most commonly used preoperative opioid was hydrocodone (50.3% acute use, 24.7% chronic use). Opioid-naïve patients had a 5-year reoperation rate of 4.7%, compared to 25.0%, 15.5%, and 23.3% with chronic preoperative use of tramadol, hydrocodone, and oxycodone. In multivariate analysis, controlling for age, sex, and Charlson Comorbidity Index, chronic use of hydrocodone (odds ratio [OR] = 2.08, P = 0.05), oxycodone (OR = 4.46, P < 0.01), and tramadol (OR = 4.01, P = 0.01) were all associated with increased reoperations. However, acute use of hydrocodone, oxycodone, and tramadol was not associated with reoperations (P > 0.05).

CONCLUSION

Both subacute and chronic use of common lower-dose opioid medications is associated with increased reoperations after single-level ACDF in nonmyelopathic patients. This information is critical when counseling patients preoperatively and developing preoperative opioid cessation programs.Level of Evidence: 3.

Surgery start time and early implant failure: A case-control study

OBJECTIVE

To evaluate the influence of surgery start time (SST) and other patient- and therapy-related variables on the risk for early implant failure (EIF) in an academic setting.

MATERIAL AND METHODS

Data were extracted from the electronic health records of 61 patients who had at least one EIF and 140 age- and gender-matched, randomly selected, non-EIF controls. Bivariate and multivariable analyses were performed to identify relevant associations between EIF and different variables, such as SST.

RESULTS

Incidence of EIF was not significantly associated with SST (HR: 1.9 for afternoon implant placement, 95% CI: 0.9-3.9; p = .105). Other factors that were associated with a significantly increased risk for EIF in a multivariable model were pre-placement ridge augmentation (HR: 7.5, 95% CI: 2.2-25.1; p = .001), intra-operative complications (HR: 5.9, 95% CI: 2.2-16.3; p < .001), simultaneous soft tissue grafting (HR: 5.03, 95% CI: 1.3-19.5; p = .020), simultaneous bone grafting (HR: 3.7, 95% CI: 1.6-8.8; p = .002), and placement with sedation (HR: 3.4, 95% CI: 1.5-7.5; p = .002).

CONCLUSIONS

While SST was not associated with the occurrence of EIF in our cohort, other variables, such as ridge augmentation prior to implant placement, simultaneous bone or soft tissue grafting, intra-operative complications, implant placement with sedation, and number of implants in the oral cavity, were associated with an increased risk for this adverse event.

Chronic Preoperative Opioids Are Associated With Revision After Rotator Cuff Repair

PURPOSE

We sought to clarify the relationship between chronic preoperative opioids and complications following rotator cuff repair. Specifically, we assessed revision, a definitive postoperative end point for surgical outcome.

METHODS

This study used PearlDiver, a United States national insurance claims database. All patients undergoing rotator cuff repair from 2008 to 2018 were identified and stratified based on a minimum of 2 opioid prescriptions within the 6 months before surgery, with 1 prescription occurring within 0 to 3 months before surgery and a second prescription within 4 to 6 months before surgery. Univariate logistic regressions of risk factors were conducted, followed by multivariate analysis of comorbidities, including ongoing preoperative opioids, any preoperative nonsteroidal anti-inflammatory drug (NSAID) prescriptions, age, sex, diabetes, tobacco, and obesity.

RESULTS

In total, 28,939 patients undergoing rotator cuff repair were identified, of whom 10,695 had opioid prescriptions within both 0 to 3 months and 4 to 6 months before index rotator cuff repair, whereas 18,244 had no opioid prescriptions within the 6-month preoperative period. In total, 977 (3.4%) patients underwent revision within 6 months, which increased to 1311 (4.5%) within 1 year of the index procedure. In the multivariate analysis controlling for age, preoperative NSAID prescriptions, tobacco, diabetes, obesity, and sex, we observed a significant association between chronic preoperative opioid prescriptions and rotator cuff repair revision (6-month odds ratio 1.12; P = .021, 1-year odds ratio 1.43; P < .001) following index procedure.

CONCLUSIONS

We report increased rates of revision within both 6 months and 1 year in patients with prolonged preoperative opioid prescriptions. The opioid cohort had greater rates of preoperative NSAID use and tobacco use, which also were observed to be independent risk factors for revision at both timepoints.

LEVEL OF EVIDENCE

III; Retrospective comparative study.

Use of Higher-strength Opioids has a Dose-Dependent Association With Reoperations After Lumbar Decompression and Interbody Fusion Surgery

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The aim of this study was to identify an association between preoperative opioid use and reoperations rates.

SUMMARY OF BACKGROUND DATA

Chronic opioid use is a public health crisis in the United States and has been linked to worse outcomes after lumbar spine surgery. However, no studies have identified an association between preoperative opioid use and reoperations rates.

METHODS

A retrospective cohort study was conducted using patients from one private insurance database who underwent primary lumbar decompression/discectomy (LDD) or posterior/transforaminal lumbar interbody fusion (PLIF/TLIF). Preoperative use of five specific opioid medications (tramadol, hydromorphone, oxycodone, hydromorphone, and extended-release oxycodone) was categorized as acute (within 3 months), subacute (acute use and use between 3 and 6 months), or chronic (subacute use and use before 6 months). Multivariate regression, controlling for multilevel surgery, age, sex, and Charlson Comorbidity Index, was used to determine the association of each medication on reoperations within 5 years.

RESULTS

A total of 11,551 patients undergoing LDD and 3291 patients undergoing PLIF/TLIF without previous lumbar spine surgery were identified. In the LDD group, opioid-naïve patients had a 5-year reoperation rate of 2.8%, compared with 25.0% and 8.0 with chronic preoperative use of hydromorphone and oxycodone, respectively. In multivariate analysis, any preoperative use of oxycodone was associated with increased reoperations (odds ratios [OR] = 1.4, 2.0, and 2.3, for acute, subacute, and chronic use; P < 0.01). Chronic use of hydromorphone was also associated with increased reoperations (OR = 7.5, P < 0.01).In the PLIF/TLIF group, opioid-naïve patients had a 5-year reoperation rate of 11.3%, compared with 66.7% and 16.8% with chronic preoperative use of hydromorphone and oxycodone, respectively. In multivariate analysis, any preoperative use of hydromorphone was associated with increased reoperations (OR = 2.9, 4.0, and 14.0, for acute, subacute, and chronic use; P < 0.05).

CONCLUSION

Preoperative use of the higher-potency opioid medications is associated with increased reoperations after LDD and PLIF/TLIF in a dose-dependent manner. Surgeons should use this data for preoperative opioid cessation counseling and individualized risk stratification.Level of Evidence: 3.

Assessment, Quantification, and Management of Fracture Pain: from Animals to the Clinic

PURPOSE OF REVIEW

Fractures are painful and disabling injuries that can occur due to trauma, especially when compounded with pathologic conditions, such as osteoporosis in older adults. It is well documented that acute pain management plays an integral role in the treatment of orthopedic patients. There is no current therapy available to completely control post-fracture pain that does not interfere with bone healing or have major adverse effects. In this review, we focus on recent advances in the understanding of pain behaviors post-fracture.

RECENT FINDINGS

We review animal models of bone fracture and the assays that have been developed to assess and quantify spontaneous and evoked pain behaviors, including the two most commonly used assays: dynamic weight bearing and von Frey testing to assess withdrawal from a cutaneous (hindpaw) stimulus. Additionally, we discuss the assessment and quantification of fracture pain in the clinical setting, including the use of numeric pain rating scales, satisfaction with pain relief, and other biopsychosocial factor measurements. We review how pain behaviors in animal models and clinical cases can change with the use of current pain management therapies. We conclude by discussing the use of pain behavioral analyses in assessing potential therapeutic treatment options for addressing acute and chronic fracture pain without compromising fracture healing. There currently is a lack of effective treatment options for fracture pain that reliably relieve pain without potentially interfering with bone healing. Continued development and verification of reliable measurements of fracture pain in both pre-clinical and clinical settings is an essential aspect of continued research into novel analgesic treatments for fracture pain.

The Cannabinoids Effect on Bone Formation and Bone Healing

PURPOSE OF REVIEW

Here, we overview the latest findings from studies investigating the skeletal endocannabinoid (EC) system and its involvement in bone formation and resorption.

RECENT FINDINGS

The endocannabinoid system consists of endogenous ligands, receptors, and enzymes. The main cannabinoids found in the cannabis plant are Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoid receptors CB1 and CB2 are expressed in bone and regulate bone homeostasis in rodents and humans. CBD treatment was shown to enhance fracture healing in rats. Recent studies in mice indicate that strain, age, and sex differences dictate the skeletal outcome of the EC activation. CBD treatment was shown to enhance bone healing, but needs validation in clinical trials. While research shows that EC activity protects against bone loss, studies on CB1 and CB2 agonists in bone regeneration models are lacking. Whether modulating the EC system would affect bone repair remains therefore an open question worth investigating.

The Effects of Chronic Preoperative Opioid Use on Single-level Lumbar Fusion Outcomes

STUDY DESIGN

A retrospective study using a national insurance claims database.

OBJECTIVE

The objective of this study was to assess the relationship between chronic preoperative opioids and the outcomes of revision surgery and nonunion after single-level lumbar fusion.

SUMMARY OF BACKGROUND DATA

Opioids are widely utilized for pain management before spine procedures. Studies have associated opioids with unfavorable postoperative outcomes, and animal models have also linked opioid administration with unstable bone healing.

METHODS

Single-level lumbar fusion patients were identified. Patients with any fracture history within 1 year before surgery were excluded. A chronic preoperative opioid cohort was defined by opioids prescriptions within 3 months prior and within 4-6 months before surgery. The rates of revision surgery within 6 months and nonunion within 6-24 months after surgery were assessed. Univariate analyses of chronic preoperative opioid prescriptions and various comorbidities for revision and nonunion were conducted followed by multivariate analyses controlling for these factors. Individual analyses were run for each of the 3 single-level lumbar fusion procedures.

RESULTS

A total of 8494 single-level lumbar fusion patients were identified. Of the 3929 (46.3%) patients filled criteria for the chronic preoperative opioid cohort, while 3250 (38.3%) patients had no opioid prescriptions within 6 months before surgery. The opioid cohort experienced significantly higher rates of both revisions (3.92% vs. 2.71%, P=0.005) and nonunion (3.84% vs. 2.89%, P=0.027) relative to the opioid-naive cohort. In the multivariate analyses, chronic preoperative opioids were identified as an independent risk factor for revision (odds ratio: 1.453, P=0.006).

CONCLUSIONS

We report that chronic opioid prescriptions before lumbar fusion may increase the risk of revision. Although these prescriptions were also associated with increased nonunion, the comparisons did not achieve statistical significance in the multivariate model. Chronic preoperative opioid use may be considered a potential risk factor in arthrodesis populations.

Opioid-free spine surgery: a prospective study of 244 consecutive cases by a single surgeon

BACKGROUND CONTEXT

There have been no reported efforts to eliminate opioid use for elective spine surgery, despite its well-known drawbacks.

PURPOSE

We sought to test the hypothesis that opioid-free elective spine surgery, including lumbar fusions, can be performed with satisfactory pain control.

STUDY DESIGN/ SETTING

This study analyzes prospectively collected data from a single surgeon's patients who were enrolled into an institutional spine registry.

PATIENT SAMPLE

We enrolled every consecutive surgical patient of author RAB between January 1, 2018 and July 13, 2019.

OUTCOME MEASURES

The postsurgical opioid use, pain scores, emergency room visits, and readmissions were tracked.

METHODS

We developed a comprehensive program for opioid-free pain control after elective spine surgery. In the initial stage, opioids were given "PRN" only, while in the second stage, they were avoided altogether. Student's t tests were performed to compare pain scores, and regression analyses were performed to understand drivers of opioid use and pain.

RESULTS

Two hundred forty-four patients were studied, a third of whom underwent lumbar fusions. In the initial stage, 47% of patients took no opioids from recovery room departure until 1-month follow-up. During the second stage, 88% of patients took no opioids during that period. Pain scores were satisfactory, and there was no association between postoperative opioid use and either procedural invasiveness or pain scores. However, preoperative opioid use was associated with a nearly fivefold increased risk of postoperative use. Ninety-three percent of lumbar fusion patients who were opioid-free before surgery did not take a single opioid in the postoperative period.

CONCLUSION

Opioid-free elective spine surgery, including lumbar fusions, is feasible and effective. We suggest that opioid-free spine surgery be offered to patients who are opioid-naïve or who can be weaned off before the operation.

The Effect of Opiates on Bone Formation and Bone Healing

PURPOSE OF REVIEW

Opioids have been shown to be associated with an increased risk of fracture. The purpose of this paper is to review recent research into the effects of opioids on bone formation and bone healing in animal models and in human studies.

RECENT FINDINGS

Most opioids, such as morphine and fentanyl, negatively affected bone remodeling and bone healing in animal models. Conversely, remifentanil has been recently shown to promote in vitro osteoblast differentiation and to inhibit differentiation and maturation of osteoclasts, therefore reducing bone resorption. According to the possible negative role of opioids in bone healing, opioid antagonists have been shown to enhance bone mineralization, suggesting a possible therapeutic role in the future for osteoporosis. Other neuropeptides, such as the vasoactive intestinal peptide (VIP) and the neuropeptide Y (NPY), have been proved to promote osteogenesis. The increased risk of fractures among opioid users may be related to their central nervous system side effects or to the reduced bone density, partly due to their endocrine effects, and partly to their direct activity on bone cells. Clinical data strongly suggested a potential negative effect of opioids in bone healing. The risk of nonunion fracture is significantly increased in opioid users, and bone mass density was reduced in patients under long-term opioid treatment. The direct effects of opioids on bone remodeling appears evident from these reports. Not all opioids have the same potential for negatively impacting bone healing. Opioid antagonists may increase bone density and could represent a possible future treatment for low bone mass density pathologies. However, further trials are warranted to clarify the clinical relevance of these emerging findings from animal studies.

Cross-Cultural Comparison of Nonopioid and Multimodal Analgesic Prescribing in Orthopaedic Trauma

BACKGROUND

After musculoskeletal injury, US providers prescribe opioids more frequently and at higher dosages than prescribers in the Netherlands and Haiti; however, the extent of variation in nonopioid analgesic prescribing is unknown. The aim of our study was to evaluate how nonopioid prescribing by orthopaedic residents varies by geographic context.

METHODS

Orthopaedic residents in three countries in which residents are the primary prescribers of postoperative analgesia in academic medical centers (Haiti, the Netherlands, and the United States) responded to surveys using vignette-based musculoskeletal trauma case scenarios. The residents chose which medications they would prescribe for postdischarge analgesia. We quantified the likelihood and dose of acetaminophen or a nonsteroidal anti-inflammatory drug prescription. We constructed multivariable regressions with generalized estimating equations to describe differences in nonopiate prescription according to country, the resident's sex and training year, and the injury site and age in the test cases.

RESULTS

Compared with residents from the United States, residents from Haiti were more likely to prescribe nonopioids (odds ratio, 3.22 [confidence interval, 1.94 to 5.34], P < 0.0001) and residents from the Netherlands nearly always prescribed nonopioids. Of those cases where one or more opioid was prescribed, providers also prescribed a nonopioid (acetaminophen or nonsteroidal anti-inflammatory drug) in 345/603 (57.2%) of US, 152/152 (100%) of Dutch, and 69/97 (71.1%) of Haitian cases (Fisher exact test P value <0.0001). Finally, providers prescribed only nonopioids for pain control in 3/348 (0.86%) of US, 32/184 (17.4%) of Dutch, and 107/176 (60.8%) of Haitian cases (Fisher exact test P < 0.0001).

CONCLUSIONS

When comparing multimodal analgesic patterns, US prescribers prescribed nonopioid analgesics less frequently than prescribers in two other countries, one low income and one high income, either in isolation or in conjunction with opioids.

An enhanced recovery after surgery pathway: association with rapid discharge and minimal complications after anterior cervical spine surgery

OBJECTIVEEnhanced recovery after surgery (ERAS) pathways are associated with improved outcomes, lower morbidity and complications, and higher patient satisfaction in multiple surgical subspecialties. Despite these gains, there are few data to guide the application of ERAS concepts to spine surgery. The authors report the development and implementation of the first ERAS pathway for patients undergoing anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA).METHODSThis was a retrospective cohort study of prospectively collected data. The authors created a multidisciplinary pathway based on best available evidence for interventions that positively influence outcomes after anterior cervical spine surgery. Patients were followed prospectively up to postoperative day 90. Patient data were collected via electronic medical record review and included demographics, comorbidities, baseline and perioperative opioid use, postoperative complications, and length of hospital stay (LOS). ERAS process measures and compliance with pathway elements were also tracked.RESULTSThirty-three patients were cared for under the pathway (n = 25 ACDF; n = 8 CDA). The median LOS was 416 minutes (interquartile range [IQR] 210-1643 minutes). Eight patients required an extended stay-longer than 23 hours. Reasons for extended admission included pain (n = 4), dyspnea (n = 1), hypoxia (n = 1), hypertension (n = 1), and dysphagia (n = 1). The median LOS for the 8 patients who required extended monitoring prior to discharge was 1585 minutes (IQR 1423-1713 minutes). Overall pathway compliance with included process measures was 85.6%. The median number of ERAS process elements delivered to each patient was 18. There was no strong association between LOS and number of ERAS process elements provided (Pearson's r = -0.20). Twelve percent of the cohort was opioid tolerant on the day of surgery. There were no significant differences between total intraoperatively or postanesthesia care unit-administered opioid, or LOS, between opioid-tolerant and opioid-naïve patients. There were no complications requiring readmission.CONCLUSIONSAn ERAS pathway for anterior cervical spine surgery facilitates safe, prompt discharge. The ERAS pathway was associated with minimal complications, and no readmissions within 90 days of surgery. Pain and respiratory compromise were both linked with extended LOS in this cohort. Further prospective studies are needed to confirm the potential benefits of ERAS for anterior cervical spine surgery, including longer-term complications, cost, and functional outcomes.

Implications of Drug Use Disorders on Spine Surgery

BACKGROUND

The opioid crisis has been declared a "public health emergency." Spine surgeons are treating more patients with substance use disorders (SUDs).

OBJECTIVE

To investigate the outcomes of patients with SUD who undergo spine surgery.

METHODS

A retrospective chart review was performed on patients with SUD who underwent nonelective spine surgery by orthopedic or neurosurgical staff from 2012 to 2017 at a level 1 trauma center and spine referral center. Three elective cases were excluded.

RESULTS

A total of 49 patients undergoing 72 surgeries were reviewed. The most common substances of abuse were opioids (44/49 patients; 90%). Of 31 patients using multisubstances (63%), 29 misused opioids. The most common indications for surgery were infection (26/49, 53%), trauma (13/49, 27%), and myelopathy (7/49, 14%). Fusions (35/49, 71%) and irrigation and debridement surgeries (12/49, 24%) predominated. Twenty-nine percent (14/49) of patients had complications, the most common being hardware failure (7/49, 14%). Twenty percent (10/49) of patients left against medical advice and 22% (11/49) did not follow up after hospital discharge. The average length of hospital stay was 22 days. Forty-five percent (22/49) of patients were known to be in a drug program preoperatively versus 39% (19/49) postoperatively. Sixty-five percent (32/49) were prescribed opioids in the immediate postoperative period and 47% (23/49) continued to abuse drugs postoperatively.

CONCLUSIONS

Patients with SUD are at increased risk of complications and inadequate follow-up. Additional studies are warranted to determine whether additional perioperative education, psychiatry consultations, or prescription of opioid addiction treatment regimens will improve drug use cessation and outcomes.

Preoperative Chronic Opioid Therapy Negatively Impacts Long-term Outcomes Following Cervical Fusion Surgery

STUDY DESIGN

Retrospective, observational.

OBJECTIVE

The aim of this study was to define the impact of preoperative chronic opioid therapy (COT) on outcomes following cervical spine fusions.

SUMMARY OF BACKGROUND DATA

Opioid therapy is a commonly practiced method to control acute postoperative pain. However, concerns exist relating to use of prescription opioids, including inherent risk of abuse, tolerance, and inferior outcomes following major surgery.

METHODS

A commercial dataset was queried from 2007 to 2015 for patients undergoing primary cervical spine arthrodesis [ICD-9 codes 81.01-81.03]. Primary outcome measures were 1-year and 2-year reoperation rates, emergency department (ED) visits, adverse events, and prolonged postoperative opioid use. Secondary outcomes included short-term outcomes including 90-day complications (cardiac, renal, neurologic, infectious, etc.). COT was defined as a history of opioid prescription filling within 3 months before surgery and was the primary exposure variable of interest. Generalized linear models investigated the association of preoperative COT on primary/secondary endpoints following risk-adjustment.

RESULTS

Overall, 20,730 patients (51.3% female; 85.9% >50 years) underwent primary cervical spine arthrodesis. Of these, 10,539 (n = 50.8%) met criteria for COT. Postoperatively, 75.3% and 29.8% remained on opioids at 3 months and 1 year. Multivariable models identified an association between COT and an increased risk of 90-day ED visit [odds ratio (OR): 1.25; P < 0.001] and wound complications (OR: 1.24; P = 0.036). At 1 year, COT was strongly associated with reoperations (OR: 1.17; P = 0.043), ED visits (OR: 1.31; P < 0.001), and adverse events including wound complications (OR: 1.32; P < 0.001), infections (OR: 1.34; P = 0.042), constipation (OR: 1.11; P = 0.032), neurological complications (OR: 1.44; P = 0.01), acute renal failure (OR: 1.24; P = 0.004), and venous thromboembolism (OR: 1.20; P = 0.008). At 2 years, COT remained a significant risk factor for additional long-term negative outcomes such as reoperations, including adjacent segment disc disease (OR: 1.21; P = 0.005), ED visits (OR: 1.32; P < 0.001), and other adverse events. Preoperative COT was associated with prolonged postoperative narcotic use at 3 months (OR: 1.30; P < 0.001), 1 year (OR: 5.17; P < 0.001), and at 2 years (OR: 5.75; P < 0.001) after cervical arthrodesis.

CONCLUSION

Preoperative COT is a modifiable risk factor that is strongly associated with prolonged postoperative opioid use. In addition, COT was associated with inferior short-term and long-term outcomes after cervical spine fusion.

LEVEL OF EVIDENCE

3.

Opioid-free anesthesia within an enhanced recovery after surgery pathway for minimally invasive lumbar spine surgery: a retrospective matched cohort study

OBJECTIVE

Enhanced recovery after surgery (ERAS) and multimodal analgesia are established care models that minimize perioperative opioid consumption and promote positive outcomes after spine surgery. Opioid-free anesthesia (OFA) is an emerging technique that may achieve similar goals. The purpose of this study was to evaluate an OFA regimen within an ERAS pathway for lumbar decompressive surgery and to compare perioperative opioid requirements in a matched cohort of patients managed with traditional opioid-containing anesthesia (OCA).

METHODS

The authors performed a retrospective analysis of prospectively collected data. They included 36 patients who underwent lumbar decompression under their ERAS pathway for spinal decompression between February and August 2018. Eighteen patients who received OFA were matched in a 1:1 ratio to a cohort managed with a traditional OCA regimen. The primary outcome was total perioperative opioid consumption. Postoperative pain scores (measured using the numerical rating scale [NRS]), opioid consumption (total morphine equivalents), and length of stay (time to readiness for discharge) were compared in the postanesthesia care unit (PACU). The authors also assessed compliance with ERAS process measures and compared compliance during 3 phases of care: pre-, intra-, and postoperative.

RESULTS

There was a significant reduction in total perioperative opioid consumption in patients who received OFA (2.43 ± 0.86 oral morphine equivalents [OMEs]; mean ± SEM), compared to patients who received OCA (38.125 ± 6.11 OMEs). There were no significant differences in worst postoperative pain scores (NRS scores 2.55 ± 0.70 vs 2.58 ± 0.73) or opioid consumption (5.28 ± 1.7 vs 4.86 ± 1.5 OMEs) in the PACU between OFA and OCA groups, respectively. There was a clinically significant decrease in time to readiness for discharge from the PACU associated with OFA (37 minutes), although this was not statistically significantly different. The authors found high overall compliance with ERAS process measures (91.4%) but variation in compliance according to phase of care. The highest compliance occurred during the preoperative phase (94.71% ± 2.88%), and the lowest compliance occurred during the postoperative phase of care (85.4% ± 5.7%).

CONCLUSIONS

OFA within an ERAS pathway for lumbar spinal decompression represents an opportunity to minimize perioperative opioid exposure without adversely affecting pain control or recovery. This study reveals opportunities for patient and provider education to reinforce ERAS and highlights the postoperative phase of care as a time when resources should be focused to increase ERAS adherence.

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.