Search

Background: Patients with a history of opioid use disorder (OUD) tend to have more complications, higher readmission rates, and increased costs following orthopaedic procedures. This study evaluated patients undergoing hallux valgus correction for their odds of increased (1) readmission rates, (2) emergency room (ER) visits, and (3) costs. Methods: Patients undergoing hallux valgus corrections with OUD history were identified using a national Medicare administrative claims database of approximately 24 million orthopaedic surgery patients. OUD patients were matched to non–opioid use disorder (NUD) patients in a 1:4 ratio by age, sex, Elixhauser-Comorbidity Index (ECI), diabetes mellitus, hyperlipidemia, hypertension, and tobacco use. The query yielded 6318 patients (OUD = 1276; NUD = 5042) who underwent a hallux valgus correction. Primary outcomes analyzed included odds of 90-day readmission rates, 30-day ER visits, and 90-day episode-of-care costs. Demographics, odds ratios (ORs), ECI, and cost were assessed as appropriate using a Pearson χ2 test, logistic regression, and a t test. A P value <.05 was considered statistically significant. Results: There were no significant differences in demographics between OUD and NUD patients. OUD patients had higher incidence and odds of 90-day readmission (9.56% vs 6.04%; OR = 1.55; P <.001) and 30-day ER visits (0.86% vs 0.35%; OR = 2.42; P =.021) and incurred greater 90-day episode-of-care costs ($7208.28 vs $6134.75; P <.001) compared with NUD patient controls. Conclusion: The study demonstrates the possible influence of OUD on higher odds of readmission, ER visits, and costs following a hallux valgus correction. Levels of Evidence: Level III: Retrospective cohort study [ABSTRACT FROM AUTHOR]

The authors of the Letter to the Editor regarding our study titled "The influence of cognitive-behavioral therapy on lumbar spine surgery outcomes: a systematic review and meta-analysis" are kindly thanked for their insight in elucidating several important considerations to our manuscript. In general, when choosing between a fixed-effects model and random effects model, prior researchers have argued the decision should be based on whether intervention effects are identical - with preference given to a random-effects model when this assumption is unlikely [[3]]. Response to the Letter to the Editor of X. Zhou et al. concerning "the influence of cognitive behavioral therapy on lumbar spine surgery outcomes: a systematic review and meta-analysis" by Parish JM, et al. (Eur Spine J [2021]; 30(5):1365-1379). [Extracted from the article]

Introduction. The sensitivity and specificity for magnetic resonance imaging (MRI) diagnosis of osteomyelitis is 90% and 80%, respectively; findings include bone marrow edema, T2-weighted image hyperintensity (HI-T2WI), T1-weighted image confluent signal(CS-T1WI), and cortical erosion (CE). The goal is to determine which risk factors and MRI findings are most predictive of osteomyelitis. Materials and Methods. After institutional review board approval, records of patients who underwent bone biopsy of the foot/ankle between 2015 and 2017 were reviewed. Diagnosis was determined histologically. Blinded MRI review identified indicators of osteomyelitis: HI-T2WI, CS-T1WI, ulcer depth, and CE. Bivariate and multivariate regression determined an association between osteomyelitis and radiographic indicators. Results. Of 59 subjects, 41 (69.5%) and 18 (30.5%) had pathologic evidence of osteomyelitis or were indeterminate. The sensitivity and specificity by radiologist diagnosis was 51.4% and 91.7%, respectively. Diabetes (relative risk [RR]=2.9, 95% CI = 1.0.8-7.77, P =.034), CS-T1WI (RR = 1.6, 95% CI = 1.23-2.20, P <.001), and CE (RR = 1.8, 95% CI = 1.34-2.28, P <.001) were risk factors on bivariate analysis. Ulcer depth demonstrated a trend toward statistical significance. Diabetes (RR = 2.4, 95% CI = 1.00-5.69, P =.049) and CE (RR = 1.7, 95% CI = 1.27-2.37, P <.001) were independent risk factors on multivariate analysis. Discussion. Diabetes and CS-T1WI are independent risk factors for pedal osteomyelitis. Patients with diabetes, CS-T1WI, and CE should be evaluated for osteomyelitis with recommendation for bone biopsy in appropriate clinical settings. Levels of Evidence: Level III Retrospective Comparative Study [ABSTRACT FROM AUTHOR]

Objective: The Patient Health Questionnaire-9 (PHQ-9) is a screening tool for evaluating depressive symptoms. Research is scarce regarding the validity and correlation of PHQ-9 scores with other patient-reported outcomes of mental health after minimally invasive lumbar discectomy (MIS LD). We aim to validate PHQ-9 as a metric for assessing mental health in MIS LD patients. Methods: A database was retrospectively reviewed for patients who underwent elective, single-level MIS LD. Patients were excluded if they had incomplete preoperative PHQ-9, 12-item Short Form Health Survey (SF-12), or Veterans RAND 12-item health survey (VR- 12). Survey scores were collected preoperatively and postoperatively through 1 year. Mean scores were used to calculate postoperative improvement from preoperative scores. Correlation of PHQ-9 with SF-12 mental composite score (MCS) and VR-12 MCS scores was also calculated. Correlation strength was assessed by the following categories: 0.1 ≤ |r| < 0.3 = low; 0.3 ≤ |r| < 0.5 =moderate; |r| ≥ 0.5 = strong. Results: A total of 239 patients underwent single-level MIS LD. PHQ-9, VR-12 MCS, and SF-12 MCS all demonstrated statistically significant increases from preoperative scores at all postoperative timepoints (p ≤ 0.001). SF-12 MCS and VR-12 MCS were each observed to have strong and significant correlations with PHQ-9 at all timepoints when evaluated with both Pearson correlation coefficients and partial correlation coefficients. Conclusion: We observed that PHQ-9, SF-12 MCS and VR-12 MCS all significantly improve following lumbar discectomy and that PHQ-9 scores strongly correlated with these previously established measures. Our results substantiate evidence from other surgical fields that PHQ-9 scores are a valid tool to evaluate pre- and postsurgical depressive symptoms. [ABSTRACT FROM AUTHOR]

Purpose: As more patients undergo lumbar spine surgery, novel interventions may improve physical and mental health outcomes. Few studies summarize the benefit of cognitive behavioral therapy (CBT) among lumbar spine surgery patients. This study collects randomized control trial data to investigate the influence of CBT on patient reported outcomes among lumbar spine surgery patients. Methods: Our study used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and a medical library expert assisted in searching PubMed/MEDLINE, Scopus, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO, and Google Scholar. We calculated standardized mean differences (SMD) to evaluate the effect size of CBT versus control groups with a sensitivity analysis. Results: Our meta-analysis included seven studies with a total of 531 patients. The majority of included studies evaluated lumbar fusion, with preoperative CBT performed by physiotherapists. The largest effects were observed for overall quality of life (SMD = 0.55 [95% CI 0.05, 1.05], p < 0.001, I2 = 86.7%) and psychological outcomes (SMD = 0.61 [95% CI 0.28, 0.94], p < 0.001, I2 = 89.7%) though disability and pain outcomes also favored CBT intervention. Included studies demonstrated low overall bias but large heterogeneity. Sensitivity analysis demonstrated negligible study design differences and revealed moderators including CBT session frequency and final follow-up duration (p < 0.001). Conclusion: Compared to usual care or alternative therapy control arms, CBT delivered the most improvement with overall quality of life and psychological outcomes. Among appropriately selected patients, CBT could improve perioperative disability, pain, quality of life, and psychological health following lumbar spine surgery. [ABSTRACT FROM AUTHOR]

Objective: There is a scarcity of research evaluating gender differences in depressive symptoms among patients undergoing cervical surgery. This study investigated gender differences with regard to depressive symptom severity, measured by Patient Health Questionnaire-9 (PHQ-9), in patients following anterior cervical discectomy and fusion (ACDF) or artificial disc replacement (ADR). Methods: A prospectively maintained surgical registry was retrospectively reviewed for eligible spine surgeries. Depressive symptom severity was evaluated by PHQ-9 at both preand postoperative timepoints (e.g., 6 weeks, 12 weeks, 6 months, 1 year, and 2 years). A chi-square test and Student t-test evaluated differences between the gender for demographic and operative variables where appropriate. Differences between the gender subgroup mean PHQ-9 scores were assessed using a t-test pre- and postoperatively (e.g., 6 weeks, 12 weeks, 6 months, and 1 year) and a paired t-test was used to assess differences from preoperative scores at each postoperative time point. Results: A total of 170 subjects underwent 125 ACDFs and 45 ADRs. Both pre- and postoperative timepoints demonstrated no significant differences between mean PHQ-9 scores by gender. Female patients demonstrated statistically significant improvement in PHQ-9 scores at 6 weeks, and 12 weeks, but not through 2 years. Male patients demonstrated statistically significant improvement in PHQ-9 scores at 6 weeks, 12 weeks, 6 months, 1 year, and 2 years. Conclusion: Although there were no significant differences between mean PHQ-9 score between the genders, there was a difference in magnitude of improvement. Females had a significant improvement in depressive symptom severity over baseline at the 6- and 12-week timepoints only, whereas males had significant improvement through 2 years postoperatively. [ABSTRACT FROM AUTHOR]

Objective: Our study aims to evaluate the correlation of Patient-Reported Outcomes Measurement Information System physical function (PROMIS PF) with legacy patient-reported outcome measures (PROMs) among patients undergoing anterior cervical discectomy and fusion (ACDF). Methods: A prospectively maintained database was retrospectively reviewed for ACDF surgeries performed between May 2015 and September 2017. Inclusion criteria were primary elective, single- or multilevel ACDFs for degenerative spinal pathology. Patients lacking preoperative or 2-year PROMIS PF surveys were excluded. Mean scores were calculated for visual analogue scale (VAS) neck, VAS arm, Neck Disability Index (NDI), 12-Item Short Form Physical Component Score (SF-12 PCS), and PROMIS PF at preoperative and 6-week, 12-week, 6-month, 1-year, and 2-year postoperative timepoints. A t-test and Pearson correlation coefficient were utilized to evaluate score improvement and PROM relationships respectively. Results: The 50 subject cohort was 60.0% male, 50% obese (body mass index = 30 kg/m2) and had an average age of 50.9 years. Significant improvements were demonstrated for VAS neck and NDI at all postoperative timepoints (p < 0.001) and for SF-12 and PROMIS PF at all timepoints except 6 weeks (p = 0.025). VAS arm improvement was seen up to 1 year (p = 0.016). PROMIS PF demonstrated strong correlations with NDI and SF-12 PCS at all evaluated timepoints and with VAS neck at all postoperative timepoints except 6 weeks (all p < 0.01). Conclusion: PROMIS PF was strongly correlated with pain, disability, and physical function up to 2 years for patients undergoing ACDF. Our results support the long-term validity of PROMIS PF for measurement of patient-reported physical function among ACDF cohorts. [ABSTRACT FROM AUTHOR]

Objective: While visual analogue score (VAS) metrics are among the most universally adopted patient-reported outcome measures (PROMs), there is limited research on the influence of back and leg pain on the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) scores. Here we assess the association of VAS back and VAS leg scores with PROMIS PF in the setting of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). Secondarily, we determine if PROMIS PF is more influenced by back or leg pain. Methods: A prospective surgical registry was reviewed from May 2015 to November 2018. Inclusion criteria were primary, single-level MIS TLIFs. We excluded multilevel procedures and patients without preoperative PROMs. Pre- and postoperative PROMIS PF, VAS back, and VAS leg scores were recorded at 6 weeks, 12 weeks, 6 months, and 1 year. A Pearson correlation evaluated PROMIS PF association with VAS back and VAS leg scores. A Fisher z-test compared correlations. Linear regression evaluated PROMIS with VAS back and VAS leg scores. Results: Our cohort was comprised of 146 subjects. 40.4% were female and the average age of 51 years. VAS back demonstrated a stronger correlation than VAS leg with PROMIS PF at all timepoints. PROMIS PF scores were negatively associated with both VAS back and VAS leg at all timepoints. Fisher z-test revealed VAS back to have a stronger correlation with PROMIS PF (p=0.025) than VAS leg. Conclusion: In the setting of MIS TLIF, physical function as evaluated by PROMIS PF, had a stronger correlation with VAS back than VAS leg at 6 months. This suggests that postoperative PROMIS PF scores may be more influenced by back pain than with leg pain. [ABSTRACT FROM AUTHOR]

Background: Development and validation of Veterans RAND 12-item (VR-12) physical component survey (PCS) has been established among civilian and veteran populations but it has not been examined among anterior cervical discectomy and fusion (ACDF) patients. Purposes/Questions: We sought to validate legacy patient-reported outcome measures (PROMs) with VR-12 PCS among patients undergoing ACDF procedures. Methods: A prospectively collected surgical registry was retrospectively evaluated for elective single or multi-level ACDFs performed for degenerative spinal pathologies from January 2014 to August 2019. Exclusion criteria included missing pre-operative surveys and surgery for trauma, metastasis, or infection. Demographic variables, baseline pathologies, and peri-operative variables were collected. A paired t test evaluated the change from the pre-operative score to each post-operative timepoint for VR-12 PCS, the 12-item Short-Form Survey (SF-12) PCS, Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), and Neck Disability Index (NDI). Minimal clinically important difference (MCID) achievement was calculated at each timepoint. Correlation was evaluated with a Pearson's correlation coefficient and time-independent partial correlation. Results: Of the 202 patients who underwent ACDF, 41.1% were female and the average age was 49.5 years. All PROMs had statistically significantly increased from baseline when compared with post-operative timepoints (12 weeks, 6 months, 1 year, and 2 years). MCID achievement rates increased through 2 years. All timepoints revealed strong VR-12 PCS correlations with SF-12 PCS, PROMIS-PF, and NDI scores. Conclusion: VR-12 PCS was strongly correlated with the well-validated SF-12 PCS and NDI metrics as well as with the more recent PROMIS-PF. All PROMs demonstrated statistically significant improvement in patients post-operatively. VR-12 PCS is a valid measure of physical function among patients undergoing ACDF. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether there is an association between preoperative 10-Item Patient Activation Measure (PAM-10) scores and clinical outcomes following MIS LD. Methods: Patients undergoing a primary MIS LD were retrospectively reviewed and stratified according to their preoperative PAM-10 scores: "low PAM," "moderate PAM," and "high PAM." Preoperative PAM score cohorts were tested for improvements in Oswestry Disability Index (ODI), 12-Item Short-Form Physical Component Score (SF-12 PCS), and Visual Analog Scale (VAS) back and leg pain using multivariate linear regression. Results: Eighty-nine patients were included: 29 had a low PAM score, 32 had a moderate PAM score, and 28 had a high PAM score. Cohorts experienced similar preoperative VAS back pain, VAS leg pain, ODI, and SF-12 PCS. Patients with low PAM scores experienced a trend of higher pain scores throughout 6 months with VAS back pain being significant at 3 months and VAS leg pain being significant at 6-week and 3-month follow-up. Patients with lower PAM scores experienced a worse improvement in ODI at 6-week, 3-month, and 6-month timepoints. Lastly, patients with lower PAM scores demonstrated less improvement in SF-12 PCS at 3-month and 6-month follow-up. Conclusions: Lower preoperative PAM scores were associated with worse improvement in clinical outcomes following MIS LD. Patients with lower PAM scores had diminished improvement in long-term patient-reported outcomes including ODI, SF-12, and VAS back and leg pain. Our investigation suggests that preoperative PAM assessments may be an effective tool to predict postoperative outcomes following MIS LD. [ABSTRACT FROM AUTHOR]

Objective: This study examines the associations between preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) score, measured by PROMIS-PF and the change between pre- and postoperative PROMIS-PF scores. Methods: A prospectively maintained surgical registry was retrospectively reviewed for spine surgeries between May 2015–June 2019. Inclusion criteria were primary, single-level minimally invasive transforaminal lumbar interbody fusions. Revisions, multilevel procedures, and patients missing preoperative surveys were excluded. Patients were grouped by preoperative PROMIS-PF scores of ≥ 35 and < 35, with higher scores indicating greater PF. A chi-squared and Student t-test were used to analyze categorical and continuous variables respectively. Linear regression evaluated the relationship of PROMIS-PF score improvement. Results: Of the 180 subjects, 84 were in the PROMIS-PF < 35 group which had more obese patients (p < 0.001) and more males (p = 0.001). Length of stay was greater for the PROMIS- PF < 35 group (36.2 hours vs. 28.7 hours, p = 0.014). PROMIS-PF and Oswestry Disability Index scores were significantly different between subgroups at all timepoints. PROMIS- PF < 35 cohort had larger postoperative PROMIS-PF improvements at 6 weeks (p = 0.008) and 12 weeks (p = 0.003). Linear regression demonstrated a negative association between preoperative PROMIS-PF scores and improvement at 6 weeks, 12 weeks, 6 months, and 2 years (p < 0.001). PROMIS-PF < 35 demonstrated significantly lower rate of achieving minimum clinically important difference at 6 months, otherwise no difference observed throughout the 2-year follow-up. Conclusion: Up to 6 months postoperatively, lower preoperative PROMIS-PF scores were associated with larger PROMIS-PF improvements. Understanding the relationship preoperative PROMIS-PF scores have with postoperative improvement may enable better patient counseling. [ABSTRACT FROM AUTHOR]

Objective: Assess preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) scores and differences between preoperative and postoperative PROMIS-PF scores for patients undergoing anterior cervical discectomy and fusion (ACDF). Methods: After Institutional Review Board approval, a prospectively maintained surgical registry was retrospectively reviewed for elective spine surgeries of nontraumatic, degenerative pathology between 2015–2018. Inclusion criteria were primary or revision, single-level ACDF procedures. Multilevel procedures and patients without preoperative surveys were excluded. A preoperative PROMIS score cutoff of 35 divided patients into PROMIS-PF score categories (e.g. , ≥ 35.0, < 35.0). Categorical and continuous variables were evaluated with chi-square tests and t-tests. Linear regression analyzed PROMIS-PF score improvement. Results: Eighty-six patients were selected, the high and low PROMIS-PF subgroups only differed in mean age (49.1 vs. 41.3, p = 0.002). Significant differences in PROMIS-PF scores were observed among high and low preoperative PROMIS-PF score subgroups at 6 weeks (p = 0.006), 12 weeks (p = 0.006), and 6 months (p = 0.014). Mean differences between preoperative and postoperative PROMIS-PF scores were significantly different between the high and low PROMIS-PF subgroups at 6 weeks (p = 0.041) and 1 year (p = 0.038). A significant negative association was observed between preoperative PROMIS scores and magnitude of improvement at the 6-week postoperative time point (slope = -0.6291, p < 0.001). Conclusion: Patients with low preoperative PROMIS-PF scores demonstrated greater improvements at 6 weeks and 1 year. Clinicians should consider patients with low preoperative PROMIS-PF scores to be in the unique position to potentially experience larger postoperative improvement magnitudes than patients with higher preoperative PROMIS-PF scores. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate specific demographic and perioperative variables associated with higher inpatient pain scores following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).Methods: Patients who underwent a single-level, primary MIS TLIF were retrospectively reviewed. Perioperative outcomes were collected, and postoperative inpatient VAS pain scores were measured. Both bivariate and stepwise multivariate Poisson regressions with robust error variance were used to assess risk factors for average inpatient pain score ≥ 5.0. A final backward stepwise regression model was created using age, gender, smoking status, diabetes status, insurance status, BMI, comorbidity burden, pedicle screw laterality, operative time, and estimated blood loss.Results: A total of 255 patients undergoing primary, single-level MIS TLIF were included. Age less than 50 years, workers' compensation insurance, preoperative VAS pain score ≥ 7, and operative duration ≥ 110 min were associated with greater postoperative pain. However, other variables such as gender, BMI, smoking status, comorbidity burden, diabetes status, and pedicle screw laterality were not associated with increased postoperative pain.Conclusion: The results of this study suggest that younger age, workers' compensation, elevated preoperative pain scores, and longer operative times are independently associated with greater inpatient pain following TLIF. Surgeons can use this information to better assess which patients may require additional pain control following TLIF. Patient expectations of postoperative outcomes in regard to pain and recovery may also be better managed. These slides can be retrieved under Electronic Supplementary Material. (paragraph). Then process the ppt slide as graphical image. [ABSTRACT FROM AUTHOR]

Objective: To assess the relationship of preoperative physical function, as measured by Patient- Reported Outcome Measurement Information System Physical Function (PROMIS PF), to improvement in mental health, as evaluated by Short Form-12 Mental Component Summary (SF-12 MCS) following anterior cervical discectomy and fusion (ACDF). Methods: Patients undergoing primary ACDF were retrospectively reviewed and stratified based on preoperative PROMIS PF scores. PROMIS PF cohorts were tested for an association with demographic characteristics and perioperative variables using chi-square analysis and multivariate linear regression. Multivariate linear regression was utilized to determine the association between PROMIS PF cohorts and improvement in SF-12 MCS. Results: A total of 129 one- to 3-level ACDF patients were included: 73 had PROMIS PF < 40 (“low PROMIS”) and 56 had PROMIS PF ≥ 40 (“high PROMIS”). The low PROMIS cohort reported worse mental health preoperatively and at all postoperative timepoints except for 1 year. Both cohorts had similar changes in mental health from baseline through the 6-month follow-up. However, at 1 year. postoperatively, the low PROMIS cohort had a statistically greater change in mental health score. Conclusion: Patients with worse preoperative physical function reported significantly worse preoperative and postoperative mental health. However, patients with worse preoperative physical function made significantly greater improvements in mental health from baseline. This suggests that patients with worse preoperative physical function can still expect significant improvements in mental health following surgery. [ABSTRACT FROM AUTHOR]

Introduction/Purpose: Patients with a history of opioid use disorder (OUD) have been shown to incur more severe medical complications, higher readmission rates, and increased cost following various orthopedic procedures. There is a scarcity in the literature investigating the effects of OUD following a hallux valgus procedure. Therefore, the purpose of this study was to evaluate whether OUD patients undergoing a hallux valgus correction are at greater odds of: 1) readmission rates, 2) emergency room (ER) visits, and 3) costs. Methods: Patients undergoing a hallux valgus correction with a history of OUD were identified using a health insurance claims database. To search for patients undergoing hallux valgus surgical corrections the following current procedural terminology (CPT) medical codes were used: 28290, 28292, 28293, 28294, 28296, 28297, 28298, 28299, 28306, and 28307. To include all eligible patients the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes were also utilized, including: 77.51 and 77.59. OUD patients were matched to non-opioid use disorder (NUD) patients in a 1:4 ratio by age, sex, Elixhauser-Comorbidity Index (ECI), diabetes mellitus, hyperlipidemia, hypertension, and tobacco use. Primary outcomes analyzed included odds of 90-day readmission rates, 30-day emergency room visit, and 90-day episode of care costs. Pearson's chi-squared test was used to compare demographics. Logistic regression analysis calculated odds-ratios for readmission and ER visits. Welch's t-test was used for significance in ECI and cost between cohorts. Results: The query yielded 6,318 patients (OUD=1,276; NUD=5,042) who underwent a hallux valgus correction. There were no significant difference between any of the compared age ranges (p=0.859, p=0.952, p=0.909, p=0.961), ECI (p=1.000) and comorbidities between OUD and NUD patients. OUD patients had higher incidence and odds of 90-day readmission rates (9.56 vs. 6.04%; OR: 1.55, p<0.001) and 30-day ER visits (.86 vs. .35%; OR: 2.42, p=0.021) compared to controls. OUD patients also incurred significantly greater 90-day episode of care costs ($7,208.28 vs. $6,134.75, p<0.0001) compared to NUD patients. Conclusion: Patients with a history of OUD who underwent a hallux valgus correction had a higher odds ratio of 90-day readmission rates, 30-day emergency room visits, and 90-day total global episode of care cost compared to those with NUD. These findings expand on a rapidly growing body of current literature that demonstrate OUD increases numerous costs associated with outcomes of foot and ankle surgery. OUD is a risk factor for poor post operative outcomes for patients undergoing a hallux valgus correction. The findings of this study are likely to improve preoperative counseling and selection when addressing patients with preoperative opioid use. [ABSTRACT FROM AUTHOR]