The association of pre-operative body pain diagram scores with pain outcomes following total knee arthroplasty

The influence of pain catastrophizing on pain and function after knee arthroplasty in knee osteoarthritis

Pain catastrophizing is an exaggerated focus on pain sensations. It may be an independent factor influencing pain and functional outcomes of knee arthroplasty. We aimed to evaluate the association between pre-operative pain catastrophizing with pain and function outcomes up to one year after knee arthroplasty. We used data from a cohort study of patients undergoing primary knee arthroplasty (either total or unicompartmental arthroplasty) for knee osteoarthritis. Pain catastrophizing was assessed pre-operatively using the Pain Catastrophizing scale (PCS). Other baseline variables included demographics, body mass index, radiographic severity, anxiety, depression, and knee pain and function assessed using the Western Ontario and McMaster University Index (WOMAC). Patients completed the WOMAC at 6- and 12-months after arthroplasty. WOMAC pain and function scores were converted to interval scale and the association of PCS and changes of WOMAC pain and function were evaluated in generalized linear regression models with adjustment with confounding variables. Of the 1136 patients who underwent arthroplasty (70% female, 84% Chinese, 92% total knee arthroplasty), 1102 and 1089 provided data at 6- and 12-months post-operatively. Mean (± SD) age of patients was 65.9 (± 7.0) years. PCS was associated with a change in WOMAC pain at both 6-months and 12-months (β = - 0.04, 95% confidence interval: - 0.06, - 0.02; P < 0.001) post-operatively after adjustment in multivariable models; as well as change in WOMAC function at 6-months and 12-months. In this large cohort study, pre-operative pain catastrophizing was associated with lower improvements in pain and function at 6-months and 12-months after arthroplasty.

Cost-Effectiveness of Community-Based Diet and Exercise for Patients with Knee Osteoarthritis and Obesity or Overweight

OBJECTIVE

Obesity exacerbates pain and functional limitation in persons with knee osteoarthritis (OA). In the Weight Loss and Exercise for Communities with Arthritis in North Carolina (WE-CAN) study, a community-based diet and exercise (D + E) intervention led to an additional 6 kg weight loss and 20% greater pain relief in persons with knee OA and body mass index (BMI) >27 kg/m2 relative to a group-based health education (HE) intervention. We sought to determine the incremental cost-effectiveness of the usual care (UC), UC + HE, and UC + (D + E) programs, comparing each strategy with the "next-best" strategy ranked by increasing lifetime cost.

METHODS

We used the Osteoarthritis Policy Model to project long-term clinical and economic benefits of the WE-CAN interventions. We considered three strategies: UC, UC + HE, and UC + (D + E). We derived cohort characteristics, weight, and pain reduction from the WE-CAN trial. Our outcomes included quality-adjusted life years (QALYs), cost, and incremental cost-effectiveness ratios (ICERs).

RESULTS

In a cohort with mean age 65 years, BMI 37 kg/m2, and Western Ontario and McMaster Universities Osteoarthritis Index pain score 38 (scale 0-100, 100 = worst), UC leads to 9.36 QALYs/person, compared with 9.44 QALYs for UC + HE and 9.49 QALYS for UC + (D + E). The corresponding lifetime costs are $147,102, $148,139, and $151,478. From the societal perspective, UC + HE leads to an ICER of $12,700/QALY; adding D + E to UC leads to an ICER of $61,700/QALY.

CONCLUSION

The community-based D + E program for persons with knee OA and BMI >27kg/m2 could be cost-effective for willingness-to-pay thresholds greater than $62,000/QALY. These findings suggest that incorporation of community-based D + E programs into OA care may be beneficial for public health.

Perioperative mental health intervention for depression and anxiety symptoms in older adults study protocol: design and methods for three linked randomised controlled trials

INTRODUCTION

Preoperative anxiety and depression symptoms among older surgical patients are associated with poor postoperative outcomes, yet evidence-based interventions for anxiety and depression have not been applied within this setting. We present a protocol for randomised controlled trials (RCTs) in three surgical cohorts: cardiac, oncological and orthopaedic, investigating whether a perioperative mental health intervention, with psychological and pharmacological components, reduces perioperative symptoms of depression and anxiety in older surgical patients.

METHODS AND ANALYSIS

Adults ≥60 years undergoing cardiac, orthopaedic or oncological surgery will be enrolled in one of three-linked type 1 hybrid effectiveness/implementation RCTs that will be conducted in tandem with similar methods. In each trial, 100 participants will be randomised to a remotely delivered perioperative behavioural treatment incorporating principles of behavioural activation, compassion and care coordination, and medication optimisation, or enhanced usual care with mental health-related resources for this population. The primary outcome is change in depression and anxiety symptoms assessed with the Patient Health Questionnaire-Anxiety Depression Scale from baseline to 3 months post surgery. Other outcomes include quality of life, delirium, length of stay, falls, rehospitalisation, pain and implementation outcomes, including study and intervention reach, acceptability, feasibility and appropriateness, and patient experience with the intervention.

ETHICS AND DISSEMINATION

The trials have received ethics approval from the Washington University School of Medicine Institutional Review Board. Informed consent is required for participation in the trials. The results will be submitted for publication in peer-reviewed journals, presented at clinical research conferences and disseminated via the Center for Perioperative Mental Health website.

TRIAL REGISTRATION NUMBERS

NCT05575128, NCT05685511, NCT05697835, pre-results.

Factors associated with pain and functional impairment five years after total knee arthroplasty: a prospective observational study

BACKGROUND

Few studies have evaluated the associations between preoperative factors and pain and physical function outcomes after total knee arthroplasty (TKA) from a mid-term perspective. Identification of such factors is important for optimizing outcomes following surgery. Thus, we examined the associations between selected preoperative factors and moderate to severe pain and pain-related functional impairment as measured using the Brief Pain Inventory (BPI), five years after TKA in patients with knee osteoarthritis.

METHODS

In this prospective observational study, all patients scheduled for primary unilateral TKA for osteoarthritis were consecutively recruited. Preoperative factors identified from previous meta-analyses were included to assess their associations with pain severity and pain-related functional impairment five years after TKA. Pain severity was the primary outcome, while pain-related functional impairment was the secondary outcome. The BPI was used to evaluate outcomes five years post-TKA. Statistically significant factors from univariate regressions were entered into a multiple logistic regression model to identify those with the strongest associations with pain severity or pain-related functional impairment five years after TKA.

RESULTS

A total of 136 patients were included, with a mean age of 67.7 years (SD 9.2) and a majority being female (68%). More severe preoperative pain (OR = 1.34, 95% CI [1.03 to 1.74]), more painful sites (OR = 1.28., 95% CI [1.01 to 1.63]), and more severe anxiety symptoms (OR = 1.14., 95% CI [1.01 to 1.28]) were associated with increased likelihood of moderate to severe pain five years after TKA surgery, while more severe osteoarthritis (OR = 0.13, 95% CI [0.03 to 0.61]) was associated with reduced likelihood of moderate to severe pain five years after TKA. More severe anxiety symptoms (OR = 1.25, 95% CI [1.08 to 1.46]) were also associated with increased likelihood of moderate to severe pain-related functional impairment five years after surgery, while male sex (OR = 0.23, 95% CI [0.05 to 0.98]) was associated with reduced likelihood of pain-related functional impairment five years after surgery.

CONCLUSION

The identified preoperative factors should be included in larger prognostic studies evaluating the associations between preoperative factors and mid-term pain severity and physical function outcomes after TKA surgery.

The Impact of Preoperative Pain on Outcomes After Vaginal Reconstructive Surgery and Perioperative Pelvic Floor Muscle Training

IMPORTANCE

The impact of preoperative pain on outcomes can guide counseling.

OBJECTIVE

The objective of this study was to compare outcomes after vaginal reconstructive surgery and pelvic muscle training between women with and without preoperative pain.

STUDY DESIGN

This is a secondary analysis of the Operations and Pelvic Muscle Training in the Management of Apical Support Loss (OPTIMAL) trial, which randomized patients to a surgical intervention (sacrospinous ligament fixation versus uterosacral vaginal vault suspension) and a perioperative behavioral intervention (pelvic floor muscle training vs usual care). Preoperative pain was defined as a response of "5" or greater on the pain scale or answering "moderately" or "quite a bit" on the Pelvic Floor Distress Inventory question "Do you usually experience pain in the lower abdomen or genital area?"

RESULTS

The OPTIMAL trial included 109 women with preoperative pain and 259 without pain. Although women with pain had worse pain scores and pelvic floor symptoms at baseline and postoperatively, they had greater improvement on pain scores (-2.3 ± 2.4 vs -0.2 ± 1.4, P < 0.001), as well as Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire scores. Among women with pain who underwent a sacrospinous ligament fixation, those who received pelvic floor muscle training had a greater reduction in pain compared with those in the usual care group (-3.0 ± 2.3 vs -1.3 ± 2.1, P = 0.008). Persistent or worsening pain was present at 24 months in 5 (16%) women with preoperative pain.

CONCLUSIONS

Women with preoperative pain experience significant improvements in pain and pelvic floor symptoms with vaginal reconstructive surgery. Pelvic floor muscle training perioperatively may be beneficial for select patients.

Surgical Treatments for Osteoarthritis

Osteoarthritis is a prevalent and disabling condition most commonly affecting the knees, hips, and hands. Since there are currently no disease-modifying therapies available, patients with persistent pain and functional impairment despite pharmacologic and other non-operative therapies should be considered for surgical management. For both knee and hip Osteoarthritis, the most common surgical approach is total joint arthroplasty, an elective surgical procedure that generally has favorable outcomes with most patients reporting significant improvements in pain, function, and quality of life. Total joint arthroplasty has relatively low complication rates, with most patients able to be discharged home following a short hospital stay. The optimal timing for undergoing total joint arthroplasty and patient appropriateness for surgery are important considerations, and the current guidelines leave timing and patient selection at the discretion of physicians. Surgical approaches for hand osteoarthritis are less common and more varied, and include both arthrodesis and arthroplasty.

Prevalence and interference of neuropathic pain in the quality of life in patients with knee osteoarthritis

OBJECTIVE

With the aging of the population, more patients have complained of pain due to knee Osteoarthritis (OA), and the number of arthroplasties has also increased. The objective of this study is to evaluate the prevalence of the neuropathic pain component in candidates for Total Knee Replacement and the effects of this component on their quality of life.

METHODS

In this cross-sectional study, patients with OA candidates for knee arthroplasty in the present institution were evaluated using the pain detection questionnaire and the Visual Analog Pain (VAS) scale to measure the pain index and the presence of associated neuropathic pain. In addition, evaluation of the quality of life and functionality using the EQ5D and SF12 questionnaires and their relationship with cases of neuropathic pain were performed.

RESULTS

One hundred twenty-six patients were evaluated, and 71.4 % were female. The age ranged from 46 to 85 years, and about 70 % of the patients had some associated clinical comorbidity. Neuropathic pain was present in 28.6 % of the patients evaluated. Patients with neuropathic pain presented worse results in the VAS evaluation, in the care, pain, and anxiety domains of the EQ5D, and in the physical and mental scores of the SF12.

CONCLUSION

Neuropathic pain was present in 28.6 % of the patients with knee OA who are candidates for arthroplasty. Patients with associated neuropathic pain present a higher level of pain and worse quality of life scores. Recognizing this type of pathology is extremely important in fully monitoring gonarthrosis.

Predicting chronic postsurgical pain: current evidence and a novel program to develop predictive biomarker signatures

ABSTRACT

Chronic pain affects more than 50 million Americans. Treatments remain inadequate, in large part, because the pathophysiological mechanisms underlying the development of chronic pain remain poorly understood. Pain biomarkers could potentially identify and measure biological pathways and phenotypical expressions that are altered by pain, provide insight into biological treatment targets, and help identify at-risk patients who might benefit from early intervention. Biomarkers are used to diagnose, track, and treat other diseases, but no validated clinical biomarkers exist yet for chronic pain. To address this problem, the National Institutes of Health Common Fund launched the Acute to Chronic Pain Signatures (A2CPS) program to evaluate candidate biomarkers, develop them into biosignatures, and discover novel biomarkers for chronification of pain after surgery. This article discusses candidate biomarkers identified by A2CPS for evaluation, including genomic, proteomic, metabolomic, lipidomic, neuroimaging, psychophysical, psychological, and behavioral measures. Acute to Chronic Pain Signatures will provide the most comprehensive investigation of biomarkers for the transition to chronic postsurgical pain undertaken to date. Data and analytic resources generatedby A2CPS will be shared with the scientific community in hopes that other investigators will extract valuable insights beyond A2CPS's initial findings. This article will review the identified biomarkers and rationale for including them, the current state of the science on biomarkers of the transition from acute to chronic pain, gaps in the literature, and how A2CPS will address these gaps.

Test-retest reliability of pain extent and pain location using a novel pain drawing analysis software application, on patients with shoulder pain

OBJECTIVES

A method of pain assessment is the drawing of pain on a specially designed manikin where the patients color the area representing their pain distribution. In recent years, software applications have been developed for the purpose of digital pain drawing data acquisition and processing. Although such specific software applications have already been released, they have been built with obsolete programming tools. The purpose of the study was to investigate the test - retest reliability of a new pain drawing analysis software, in a sample of patients with shoulder pain.

METHODS

Data collected from 31 subjects with shoulder pain. Participants were asked twice to color their pain distribution in the painting environment of a tablet software application called 'Pain Distribution.'

RESULTS

The reliability of pain extent was found to be good (ICC = 0.80). The Jaccard index for the reliability of pain location was found to be moderate, equal to 42.02 ± 19.13%.

CONCLUSION

The results demonstrated good reliability of pain extent and moderate reliability of pain location using the new pain distribution analysis application 'Pain Distribution.' This pain drawing software application could be a reliable, inexpensive, and clinically usable solution for assessing the distribution of pain in patients with shoulder pain.

Does gabapentin provide benefit for patients with knee OA? A benefit-harm and cost-effectiveness analysis

OBJECTIVE

Gabapentin can treat neuropathic pain syndromes and has increasingly been prescribed to treat nociplastic pain. Some patients with knee osteoarthritis (OA) suffer from both nociceptive and nociplastic pain. We examined the cost-effectiveness of adding gabapentin to knee OA care.

METHOD

We used the Osteoarthritis Policy Model, a validated Monte Carlo simulation of knee OA, to examine the value of gabapentin in treating knee OA by comparing three strategies: 1) usual care, gabapentin sparing (UC-GS); 2) targeted gabapentin (TG), which provides gabapentin plus usual care for those who screen positive for nociplastic pain on the modified PainDETECT questionnaire (mPD-Q) and usual care only for those who screen negative; and 3) universal gabapentin plus usual care (UG). Outcomes included cumulative quality-adjusted life years (QALYs), lifetime direct medical costs, and incremental cost-effectiveness ratios (ICERs), discounted at 3% annually. We derived model inputs from published literature and national databases and varied key input parameters in sensitivity analyses.

RESULTS

UC-GS dominated both gabapentin-containing strategies, as it led to lower costs and more QALYs. TG resulted in a cost increase of $689 and a cumulative QALY reduction of 0.012 QALYs. UG resulted in a further $1,868 cost increase and 0.036 QALY decrease. The results were robust to plausible changes in input parameters. The lowest TG strategy ICER of $53,000/QALY was reported when mPD-Q specificity was increased to 100% and AE rate was reduced to 0%.

CONCLUSION

Incorporating gabapentin into care for patients with knee OA does not appear to offer good value.

Central Sensitization Is Associated with Inferior Patient-Reported Outcomes and Increased Osteotomy Site Pain in Patients Undergoing Medial Opening-Wedge High Tibial Osteotomy

Background and Objectives: Studies have shown that centrally sensitized patients have worse clinical outcomes following total knee arthroplasty (TKA) than non-centrally sensitized patients. It is unclear whether central sensitization (CS) affects patient-reported outcomes (PROs) and/or level of osteotomy site pain in patients undergoing medial opening-wedge high tibial osteotomy (MOWHTO). The purpose of this study was to determine whether CS is associated with PROs and osteotomy site pain following MOWHTO. Materials and Methods: A retrospective evaluation was conducted on 140 patients with varus knee osteoarthritis (OA) who were treated with MOWHTO and monitored for two years. Before surgery, the Central Sensitization Inventory (CSI) was used to assess CS status, and a CSI of 40 or higher was considered indicative of CS. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and pain visual analogue scale (VAS) were used to assess PROs. The minimal clinically important difference (MCID) for the WOMAC was set as 4.2 for the pain subscore, 1.9 for the stiffness subscore, 10.1 for the function subscore, and 16.1 for the total based on the results of a previous study. The WOMAC score, pain VAS score of the osteotomy site, and the achievement rates of WOMAC MCID were compared between the CS and non-CS groups. Results: Thirty-seven patients were assigned to the CS group, whereas 84 were assigned to the non-CS group. Before surgery, the CS group showed a higher WOMAC score than the non-CS group (58.7 vs. 49.4, p < 0.05). While there was a statistically significant improvement in WOMAC subscores (pain, stiffness, function, and total) for both groups at two years after surgery (all p < 0.05), the CS group had a higher WOMAC score than the non-CS group (37.1 vs. 21.8, p < 0.05). The CS group showed significantly inferior results in pre- and postoperative changes of WOMAC subscores (pain, function, and total) relative to the non-CS group (all p < 0.05). In addition, pain at the osteotomy site was more severe in the CS group than in the non-CS group at two years after surgery (4.8 vs. 2.2, p < 0.05). Patients with CS had worse MCID achievement rates across the board for WOMAC pain, function, and total scores (all p < 0.05) compared to the non-CS group. Conclusions: Centrally sensitized patients following MOWHTO had worse PROs and more severe osteotomy site pain compared to non-centrally sensitized patients. Furthermore, the WOMAC MCID achievement rate of patients with CS was lower than that of patients without CS. Therefore, appropriate preoperative counseling and perioperative pain management are necessary for patients with CS undergoing MOWHTO. Level of Evidence: Level III, case-control study.

The Role of Pain Catastrophizing, Emotional Intelligence, and Pain Intensity in the Quality of Life of Cancer Patients with Chronic Pain

Pain catastrophizing (PC) is a negative cognitive distortion to actual or anticipated pain. This study aims to investigate the relationship between pain catastrophizing, emotional intelligence, pain intensity, and quality of life (QoL) in cancer patients with chronic pain. Eighty-nine outpatients with chronic pain attending pain clinics and palliative care units were recruited. Participants were men (42.7%) and women (57.3%) with an average age of 56.44 years (SD = 14.82). Self-report psychological measures were completed, including a measure of emotional intelligence, a standard measure of PC, a scale assessing pain intensity, and a scale measuring QoL. The PC scale was found to assess three correlated yet different dimensions of pain catastrophizing (helplessness, magnification, and rumination). Moreover, as expected, patients with PC scale scores ≥ 30 had lower scores in functional QoL dimensions and higher scores in the fatigue, pain, and insomnia symptom dimensions. Regression analyses demonstrated that PC (B = − 0.391, p = 0.004), pain intensity (B = − 1.133, p < 0.001), and education (B = 2.915, p = 0.017) remained the only significant variables related to QoL, when controlling for demographic and clinical confounders. Regarding mediating effects, PC and pain intensity were jointly found to be significant mediators in the relationship between emotional intelligence and QoL. Results are discussed in the context of the clinical implications regarding interventions designed to improve cancer patients’ quality of life and offer new insight, understanding, and evaluation targets in the field of pain management.

Is inpatient rehabilitation a predictor of a lower incidence of persistent knee pain 3-months following total knee replacement? A retrospective, observational study

Background

Moderate to severe levels of persistent knee pain have been estimated to affect up to 25% of people 3-months or more after a total knee replacement. It is unknown whether the type of rehabilitation pathway is associated with persistent high pain after surgery. Using a prospectively followed Australian cohort who underwent total knee replacement for knee osteoarthritis, this study aimed to i) report the incidence of high-intensity knee pain (defined as a score ≤ 15 on the Oxford Knee Score pain subscale) across time and ii) identify whether referral to inpatient rehabilitation was one of the predictors of persistent pain at 3-months post-surgery.

Methods

A retrospective analysis of a large prospective study was conducted using the Oxford Knee Score pain subscale to determine if participants had high pain at 3-months, 12-months and 36-months post-surgery. Relative risks for high pain at 3-, 12- and 36-months between the type of rehabilitation pathway were determined using Poisson multivariable regression with robust standard errors. The same technique was also employed to determine potential predictors, including rehabilitation pathway, of high pain at 3 months.

Results

The incidence of high pain in all participants was 73% pre-surgery and 10, 5 and 6% at 3-, 12- and 36-months respectively following knee replacement. There was a significant interaction between time and rehabilitation pathway, suggesting that the effect of the rehabilitation pathway varied across time. The incidence of high pain at 3-months did not significantly differ between those who attended inpatient rehabilitation (11.6%) and those discharged directly home (9.5%). Multivariable Poisson regression analysis identified the pre-surgical presence of high pain, co-morbid low back pain or other lower limb problem, younger age and having a major complication within 3-months following surgery as significant predictors of persistent pain whilst discharge to inpatient rehabilitation was not.

Conclusion

A small but clinically significant minority of people continued to have high pain levels at 3-, 12- and 36-months following a primary total knee replacement for osteoarthritis. Participation in an inpatient rehabilitation program does not appear to be an important predictor of ongoing knee pain.

Trial registration

The data were collected in the Evidence-based Processes and Outcomes of Care (EPOC) study, ClinicalTrials.gov Identifier: NCT01899443

Correlations in radiographic and MAKO Total Knee Robotic-Assisted Surgery intraoperative limb coronal alignment

Robotic-assisted arthroplasty has become increasingly established in recent years. The aim of the study is to determine if intraoperative coronal alignment during robotic-assisted total knee arthroplasty correlates with radiographic alignment. We prospectively compared the pre- and postoperative limb alignment values measured on long leg standing radiographs with intraoperative robotic-assisted measurements for 100 patients who underwent primary total knee arthroplasty. Two-tailed bivariate Pearson correla- tions were performed to evaluate the strength of the association between radiographic and robotic- assisted alignment. The intraclass correlation coeffi- cient (ICC) was used to estimate interrater reliability. There was a male/female ratio of 1.16 and the mean age was 67 years (range 42-88). Robotic-assisted measurements slightly overestimated the degree of varus relative to radiographs. Radiographic and robotic-assisted measurements were strongly correlated (r = 0.915, p < 0.001) preoperatively, with a difference of 1.6 ± 3.2°. The average measure ICC was 0.996 with a 95% confidence interval from 0.995 to 0.997 (p < 0.001). Postoperatively a bigger difference was measured (3.1° ± 1.9°), comparing radiographic and MAKO alignment. A moderate correlation was observed between the postoperative radiographic and MAKO outcome alignment (r = 0.604, p < 0.001). The average measure ICC was 0.977 with a 95% confidence interval from 0.967 to 0.984 (p < 0.001). There is a strong correlation in the preoperative set- ting between radiographic and robotic-assisted lower limb alignment and a moderate correlation in the post-operative setting. The values measured by the MAKO Total Knee application were considerably more in varus.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

Diagnosis of Central Sensitization and Its Effects on Postoperative Outcomes following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Central sensitization (CS) has been extensively researched as a cause of persistent pain after total knee arthroplasty (TKA). This systematic review study sought to investigate the diagnosis of CS in patients who underwent TKA for knee osteoarthritis (OA) and the effect of CS on clinical outcomes after TKA. Three comprehensive databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched for studies that evaluated the outcomes of TKA in knee OA patients with CS. Data extraction, risk of bias assessment, and (where appropriate) meta-analysis were performed. The standardized mean difference (SMD) with a 95% confidence interval was used to assess the different scales of pain. A total of eight studies were selected, including two retrospective studies and five prospective observational studies. One study used additional randomized controlled trial data. Five studies were finally included in the meta-analysis. All studies had a minimum follow-up period of 3 months. The Central Sensitization Inventory (CSI), whole-body pain diagram, and quantitative sensory testing (QST) were used for measuring CS. The pooled analysis showed that patients with CS had more severe postoperative pain after TKA (SMD, 0.65; 95% CI, 0.40−0.90; p < 0.01) with moderate heterogeneity (I2 = 60%). In patients who underwent TKA with knee OA, CSI is most often used for the diagnosis of CS, and the QST and whole-body pain diagram are also used. CS is closely associated with more severe and persistent pain after TKA.

Multi-Site Observational Study to Assess Biomarkers for Susceptibility or Resilience to Chronic Pain: The Acute to Chronic Pain Signatures (A2CPS) Study Protocol

Chronic pain has become a global health problem contributing to years lived with disability and reduced quality of life. Advances in the clinical management of chronic pain have been limited due to incomplete understanding of the multiple risk factors and molecular mechanisms that contribute to the development of chronic pain. The Acute to Chronic Pain Signatures (A2CPS) Program aims to characterize the predictive nature of biomarkers (brain imaging, high-throughput molecular screening techniques, or "omics," quantitative sensory testing, patient-reported outcome assessments and functional assessments) to identify individuals who will develop chronic pain following surgical intervention. The A2CPS is a multisite observational study investigating biomarkers and collective biosignatures (a combination of several individual biomarkers) that predict susceptibility or resilience to the development of chronic pain following knee arthroplasty and thoracic surgery. This manuscript provides an overview of data collection methods and procedures designed to standardize data collection across multiple clinical sites and institutions. Pain-related biomarkers are evaluated before surgery and up to 3 months after surgery for use as predictors of patient reported outcomes 6 months after surgery. The dataset from this prospective observational study will be available for researchers internal and external to the A2CPS Consortium to advance understanding of the transition from acute to chronic postsurgical pain.

Cross-validation of good versus poor self-reported outcome trajectory types following knee arthroplasty

OBJECTIVE

To determine whether good versus poor outcome trajectories and predictors of poor outcome obtained in a derivation study could be replicated in an independent sample of persons undergoing knee arthroplasty (KA).

METHODS

We used data from TRIO-POPULAR, a prospective cohort study of 926 participants who underwent KA in the United Kingdom. The participants were assessed preoperatively and 6-weeks, 6- and 12-months postoperatively. The Oxford Knee Score was the primary outcome and a variety of pre-operative predictors of outcome were selected. The outcome measure and the predictors were selected to most closely align with a previously published derivation study of good versus poor outcome. Confirmatory two-piece latent class growth curve analyses were used to model outcome and regression was used to identify predictors of outcome class.

RESULTS

Trajectories for the Oxford Knee Scores from TRIO-POPULAR replicated trajectories for WOMAC Pain and Function scores from the previously published derivation study. Multivariable predictors of poor outcome were pain catastrophizing (odds ratio = 1.125, 95% CI = 1.048, .206, p = 0.001) and comorbidity (odds ratio = 1.134, 95%CI = 1.049, 1.227, p = 0.002. Pain catastrophizing also predicted poor outcome in the derivation study.

CONCLUSIONS

Good and poor outcome trajectories replicated those found in the previously published derivation study. Our model-based method produces stable outcome trajectories despite using data from different countries and participants with substantively different characteristics. Predictors of poor outcome were somewhat inconsistent between the cross-validation and derivation studies. Pain catastrophizing was the only consistent poor outcome predictor.

The impact of preoperative pelvic pain on outcomes after vaginal reconstructive surgery

BACKGROUND

Pelvic pain is a debilitating condition that is common among women with pelvic floor disorders. Limited information is known about the impact of preoperative pelvic pain on outcomes after vaginal reconstructive surgery.

OBJECTIVE

This study aimed to compare the outcomes after vaginal reconstructive surgery between women with and without preoperative pelvic pain.

STUDY DESIGN

Baseline and postoperative data were analyzed from the "Outcomes Following Vaginal Prolapse Repair and Midurethral Sling trial." The multicenter trial involved women with anterior prolapse without symptoms of stress incontinence randomized to receive either a midurethral sling or sham incisions during a vaginal reconstructive surgery. Participants completed the visual analog scale adapted for suprapubic pain and Pelvic Floor Distress Inventory at baseline, 3 months, and 12 months. Preoperative pelvic pain was defined as a response of "5" or greater on pain on the visual analog scale or answering "moderately" or "quite a bit" on the Pelvic Floor Distress Inventory question, "Do you usually experience pain in the lower abdomen or genital area?" Outcomes and complication rates were compared between women with and without pelvic pain.

RESULTS

The "Outcomes Following Vaginal Prolapse Repair and Midurethral Sling trial" participants included 112 women with pelvic pain (58 had a midurethral sling and 54 had sham incisions) and 212 women without pelvic pain (105 had a midurethral sling and 107 had sham incisions). Women who had a midurethral sling and pelvic pain were younger than women without pelvic pain (60.3±12.1 vs 65.1±8.6; P=.004). Women who had sham incisions and pelvic pain were more likely of Hispanic ethnicity than women without pelvic pain (27.8% vs 9.4%; P=.002). Patient improvement based on the Patient Global Impression of Improvement scale did not differ between arms. Women with pelvic pain had greater improvement on the visual analog scale pain scores after a surgical procedure at 3 months (-3.1±2.9 vs -0.4±1.6; P<.001) and at 12 months (-3.4±3.0 vs -0.6±1.6; P<.001) than women without pain, although their pain scores remained higher than those without preoperative pelvic pain at all time points (P<.001 for all). Similar improvements were found on the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire. The differences observed were not affected by whether women were in the midurethral sling or sham arm of the trial. Postoperative urinary tract infection and incomplete bladder emptying did not differ between the groups.

CONCLUSION

Women with preoperative pelvic pain experienced significant improvements in pain and pelvic floor symptoms with vaginal reconstructive surgery and had similar subjective improvement postoperatively compared with women without preoperative pelvic pain. Reassuringly, the performance of a midurethral sling did not have an impact on the results.

Phase 3 Trials of Enhanced Versus Usual Care Physical Therapy for Patients at Risk of Poor Outcome Following Knee Arthroplasty: A Perspective on Meaning and a Way Forward

Physical therapy is routinely delivered to patients after discharge from the hospital following knee arthroplasty. Posthospitalization physical therapy is thought to be beneficial, particularly for those patients most at risk of poor outcome, the subgroup with persistent function-limiting pain, despite an apparently successful surgery. Research teams have undertaken 3 large-scale multicenter Phase 3 randomized clinical trials designed specifically for patients at risk of poor outcome following knee arthroplasty. All 3 trials screened for poor outcome risk using different methods and investigated different physical therapist interventions delivered in different ways. Despite the variety of types of physical therapy and mode of delivery, all trials found no effects of the enhanced treatment compared with usual care. In all cases, usual care required a lower dosage of physical therapy compared with the enhanced interventions. This Perspective compares and contrasts the 3 trials, speculates on factors that could explain the no-effect findings, and proposes areas for future study designed to benefit the poor outcome phenotype.

Using a postoperative pain trajectory to predict pain at 1 year after total knee arthroplasty

BACKGROUND

The pain trajectory is an early detection/prediction method for chronic postsurgical pain (CPSP). It is unclear whether a pain trajectory can predict CPSP in patients who have undergone a total knee arthroplasty (TKA). Here we investigated (1) whether CPSP can be predicted in TKA patients, and (2) the values that can be used to predict CPSP.

METHODS

We studied 211 postoperative TKA patients. We calculated the pain trajectory (pain curve slope and intercept) using the patients' self-reported pain intensity values at 1, 3, 5, and 7 days post-TKA. Using structural equation modeling (SEM), we performed a multiple regression analysis to investigate appropriate prediction models for the pain trajectory. Classification and regression tree (CHAID) methodology was used to calculate values to predict CPSP by a decision tree model. CPSP (dependent variable) was defined as >30 mm on a visual analog scale for pain intensity at 1 year post-TKA. The predictor variables were pain curve slope, intercept, age, sex, body mass index, and preoperative pain intensity.

RESULTS

The pain trajectory was the best fit among the models to predict pain intensity at 1 year post-TKA. When the pain curve slope (pain trajectory) was greater than 2.8, the probability of CPSP at 1 year post-TKA was 33.3%.

CONCLUSION

Our results suggest that the pain trajectory could be applied to post-TKA patients and used to calculate clinical values to predict CPSP. Our findings also indicate the possibility that patients with a positive pain curve slope in the first postoperative week may need early intervention to avoid CPSP.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

The predictive significance of bone mineral density on postoperative pain relief in knee osteoarthritis patients after total knee arthroplasty: A prediction model

BACKGROUND

Bone mineral density (BMD) may be an important factor affecting the clinical outcomes after total knee arthroplasty (TKA). However, further information regarding BMD in postoperative pain relief is not present yet. This study aims to gain further insight into the predictive significance of BMD in postoperative pain relief in knee osteoarthritis (KOA) patients after TKA.

METHODS

156 KOA patients treated by TKA were included in this study. Visual analogue scale (VAS) was used to measure the pain intensity in patients within one year after TKA. The patients were divided into good pain relief group (the improvement of VAS ≥ 3) and poor pain relief group (the improvement of VAS < 3). BMD and other clinical characteristics were also collected. Logistic regression analysis and receiver operating characteristic curve (ROC curve) were used to evaluate the predictive significance of BMD. Subgroup analysis was used to compare the difference of postoperative pain between High BMD group and Low BMD group extra.

RESULTS

34 (21.8%) patients had poor pain relief after TKA. Logistic regression analysis indicated that age, BMD, preoperative hospital for special surgery (HSS) scores, preoperative VAS score and postoperative posterior slope angles (PSA) were the risk factors of poor pain relief (P < 0.05). Using BMD as a predictor, the optimum cut-off value of poor pain relief was T-level = -3.0 SD in the ROC curve, where sensitivity and specificity were 73.5% and 83.7%, respectively. Based on this cut-off value, obvious pain relief was observed in the High BMD group compared with Low BMD group from the 6th month after TKA in the subgroup analysis (P < 0.05).

CONCLUSIONS

BMD is an effective predictor for postoperative pain relief in KOA patients after TKA, and the poor pain relief should be fully considered especially when BMD T-level ≤ -3.0 SD.

Postoperative Psychosocial Factors in Health Functioning and Health-Related Quality of Life After Knee Arthroplasty: A 6-Month Follow up Prospective Observational Study

OBJECTIVE

Knee arthroplasty (KA) is an effective and cost-effective treatment for end-stage knee osteoarthritis. Despite high surgical success rates, as many as 25% of patients report compromised postoperative functioning, persistent pain, and reduced quality of life. The purpose of this study was to assess the predictive value of psychological factors in health functioning and quality of life, during a 6-month period after KA.

DESIGN

A prospective observational study.

SETTING

Surgery at two hospitals and follow-up was carried out through the domiciliary rehabilitation service.

SUBJECTS

In total, 89 patients (age 70.27 ± 7.99 years) met the inclusion criteria.

METHOD

A test battery composed of Health functioning associated with osteoarthritis (WOMAC), Health-related quality of life (EQ-5D-5L), Anxiety and Depression (HADS), Pain attitudes (SOPA-B), Pain catastrophizing (PCS), and Fear of Movement (TSK-11) was assessed at 1 week, and 1, 3, and 6 months after surgery. A mixed effects linear model was used to estimate the effect of time and covariates. An exploratory factor analysis was used to identify the number of dimensions underlying the group of psychological measurements.

RESULTS

In WOMAC model, anxiety level (F = 120.8), PCS (F = 103.9), depression level (F = 93.6) and pain score (F = 72.8) were the most influential variables. Regarding EQ-5D-5L model, anxiety level (F = 98.5), PCS (F = 79.8), depression level (F = 78.3) and pain score (F = 45) were the most influential variables. Pain score and the psychosocial variables of PCS, TSK, HADS-A, HADS-D, SOPA-B Emotion, SOPA-B Harm and SOPA-B Disability loaded in one single dimension.

CONCLUSIONS

Postoperative acute pain and psychosocial factors of pain catastrophizing, anxiety, depression, and pain attitudes might influence health functioning and quality of life during KA rehabilitation. Such factors could be gathered into one single dimension defined as pain-related psychologic distress.

Sensory-Discriminative Three-Dimensional Body Pain Mobile App Measures Versus Traditional Pain Measurement With a Visual Analog Scale: Validation Study

Background

To quantify pain severity in patients and the efficacy treatments, researchers and clinicians apply tools such as the traditional visual analog scale (VAS) that leads to inaccurate interpretation of the main sensory pain.

Objective

This study aimed to validate the pain measurements of a neuroscience-based 3D body pain mobile app called GeoPain.

Methods

Patients with temporomandibular disorder (TMD) were assessed using GeoPain measures in comparison to VAS and positive and negative affect schedule (PANAS), pain and mood scales, respectively. Principal component analysis (PCA), scatter score analysis, Pearson methods, and effect size were used to determine the correlation between GeoPain and VAS measures.

Results

The PCA resulted in two main orthogonal components: first principal component (PC1) and second principal component (PC2). PC1 comprises a combination score of all GeoPain measures, which had a high internal consistency and clustered together in TMD pain. PC2 included VAS and PANAS. All loading coefficients for GeoPain measures in PC1 were above 0.70, with low loadings for VAS and PANAS. Meanwhile, PC2 was dominated by a VAS and PANAS coefficient >0.4. Repeated measure analysis revealed a strong correlation between the VAS and mood scores from PANAS over time, which might be related to the subjectivity of the VAS measure, whereas sensory-discriminative GeoPain measures, not VAS, demonstrated an association between chronicity and TMD pain in locations spread away from the most commonly reported area or pain epicenter (P=.01). Analysis using VAS did not detect an association at baseline between TMD and chronic pain. The long-term reliability (lag >1 day) was consistently high for the pain area and intensity number summation (PAINS) with lag autocorrelations averaging between 0.7 and 0.8, and greater than the autocorrelations for VAS averaging between 0.3 and 0.6. The combination of higher reliability for PAINS and its objectivity, displayed by the lack of association with PANAS as compared with VAS, indicated that PAINS has better sensitivity and reliability for measuring treatment effect over time for sensory-discriminative pain. The effect sizes for PAINS were larger than those for VAS, consequently requiring smaller sample sizes to assess the analgesic efficacy of treatment if PAINS was used versus VAS. The PAINS effect size was 0.51 SD for both facial sides and 0.60 SD for the right side versus 0.35 SD for VAS. Therefore, the sample size required to detect such effect sizes with 80% power would be n=125 per group for VAS, but as low as n=44 per group for PAINS, which is almost a third of the sample size needed by VAS.

Conclusions

GeoPain demonstrates precision and reliability as a 3D mobile interface for measuring and analyzing sensory-discriminative aspects of subregional pain in terms of its severity and response to treatment, without being influenced by mood variations from patients.

Widespread Pain Is Associated with Increased Risk of No Clinical Improvement After TKA in Women

BACKGROUND

When conservative treatments do not work, TKA may be the best option for patients with knee osteoarthritis, although a relatively large proportion of individuals do not have clinically important improvement after TKA. Evidence also suggests that women are less likely to benefit from TKA than men, but the reasons are unclear. Widespread pain disproportionately affects women and has been associated with worse outcomes after joint arthroplasty, yet it is unknown if the effect of widespread pain on TKA outcomes differs by patient gender.

QUESTIONS/PURPOSES

(1) Does the association between widespread pain and no clinically important improvement in osteoarthritis-related pain and disability 2 years after TKA differ between men and women? (2) Does the use of pain medications 2 years after TKA differ between those with widespread pain and those without widespread pain before surgery?

METHODS

Osteoarthritis Initiative (https://nda.nih.gov/oai/) study participants were followed annually from March 2005 until October 2015. Participants who underwent TKA up to the 7-year follow-up visit with pain/disability assessment at the protocol-planned visit before TKA and at the second planned annual visit after surgery were included in the analysis. Among 4796 study participants, 391 had a confirmed TKA, including 315 with pain/disability assessment at the protocol-planned visit before TKA. Overall, 95% of participants (298) had the required follow-up assessment; 5% (17) did not have follow-up data. Widespread pain was defined based on the modified American College of Rheumatology criteria. Symptoms were assessed using the WOMAC pain (range 0 to 20; higher score, more pain) and disability (range 0 to 68; higher score, more disability) scores, and the Knee Injury and Osteoarthritis Outcome Score for pain (range 0 to 100; higher score, less pain). Improvements in pain and disability were classified based on improvement from established clinically important differences (decrease in WOMAC pain ≥ 1.5; decrease in WOMAC disability ≥ 6.0; increase in Knee Injury and Osteoarthritis Outcome Score for pain ≥ 9). At baseline, more women presented with widespread pain than men (45% [84 of 184] versus 32% [36 of 114]). Probability and the relative risk (RR) of no clinically important improvement were estimated using a logistic regression analysis in which participants with widespread pain and those without were compared. The analyses were done for men and women separately, then adjusted for depression and baseline outcome scores.

RESULTS

Among women, preoperative widespread pain was associated with an increased risk of no clinically important improvement 2 years after TKA, based on WOMAC pain scores (13.5% versus 4.6%; RR 2.93 [95% CI 1.18 to 7.30]; p = 0.02) and the Knee Injury and Osteoarthritis Outcome Score for pain (16.5% versus 4.9%; RR 3.39 [95% CI 1.34 to 8.59]; p = 0.02). Given the lower and upper limits of the confidence intervals, our data are compatible with a broad range of disparate associations between widespread pain and lack of clinically important improvement in WOMAC pain scores (RR 0.77 [95% CI 0.22 to 2.70]; p = 0.68) and the Knee Injury and Osteoarthritis Outcome Score for pain (RR 1.37 [95% CI 0.47 to 4.00]; p = 0.57) among men, as well as clinically important improvement in WOMAC disability scores among men (RR 0.72 [95% CI 0.20 to 2.55]; p = 0.61) and women (RR 1.98 [95% CI 0.92 to 4.26]; p = 0.08). Participants presenting with widespread pain before TKA were more likely than those without widespread pain to use medication for symptoms of knee osteoarthritis most days for at least 1 month 2 years after TKA (51% [61 of 120] versus 32% [57 of 178]; mean difference, 18.8 [95% CI 7.3 to 30.1]; p < 0.01).

CONCLUSIONS

Widespread pain before TKA was associated with an increased risk of no clinically important improvement in knee pain 2 years postoperatively among women. Because of the small number of men with widespread pain in the sample, the results for men were inconclusive. In clinical practice, screening TKA candidates for widespread pain may be useful, and expectations of surgical outcomes may need to be tempered if patients have a concurrent diagnosis of widespread pain. Future studies should include more men with widespread pain and investigate if treatment of widespread pain before or concurrent with TKA surgery may improve surgical outcomes.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Stability of Measures of Pain Catastrophizing and Widespread Pain Following Total Knee Replacement

OBJECTIVE

Pain catastrophizing and widespread pain are predictors of pain chronicity/severity. Gaps remain in our understanding of the extent to which each is a stable (trait) or dynamic (state) variable. We undertook this study to assess the stability of each variable from before to after total knee replacement (TKR) and whether changes are explained by pain improvements.

METHODS

We used data from a prospective study of TKR recipients ages ≥40 years. Questionnaires included body pain diagrams assessing widespread pain, the Pain Catastrophizing Scale (PCS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. We divided subjects into widespread pain groups (0 versus 1-2 versus ≥3 pain regions) and into low and high PCS score groups (<16 versus ≥16). We assessed changes in group membership from pre-TKR to 12 months post-TKR, then compared these changes between subjects with most and least WOMAC pain improvement.

RESULTS

A total of 176 subjects completed scales at both time points; 64% were female, the mean age was 66 years, and baseline median WOMAC pain score was 40. In all, 71% of subjects in the high PCS score group improved to join the low PCS score group at follow-up. While 73 subjects (41%) changed widespread pain group, they were similarly likely to worsen and to improve. We found a statistically significant positive association of improvement in WOMAC pain score with improvement in PCS score (r = 0.31), but not widespread pain (r = -0.004).

CONCLUSION

The PCS score reflects state-like aspects of catastrophizing that diminish along with pain. In contrast, widespread pain scores worsened and improved equally often, regardless of knee pain relief. The findings urge caution in interpreting PCS score and widespread pain as trait measures in musculoskeletal research.

Racial Differences in Pain and Function Following Knee Arthroplasty: A Secondary Analysis From a Multicenter Randomized Clinical Trial

OBJECTIVE

The assessment of racial differences in pain and function outcome following knee arthroplasty (KA) has received little attention despite very substantial literature exploring a variety of other prognostic factors. The present study was undertaken to determine whether race was associated with KA outcome after accounting for potential confounding factors.

METHODS

We conducted a secondary analysis of a randomized clinical trial of 384 participants with moderate-to-high pain catastrophizing who underwent KA. Preoperative measures included race/ethnicity status as well as a variety of potential confounders, including socioeconomic status, comorbidity, and bodily pain. Outcome measures were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scales as well as performance measures. Linear mixed-effects models compared outcomes over a 1-year follow-up period for African American versus non-African American participants.

RESULTS

WOMAC pain scores differences for African American versus non-African American participants averaged ~2 points in unadjusted analyses and 1-1.5 points in adjusted analyses. In adjusted analyses, follow-up WOMAC function scores differed by 6 points for African Americans compared to non-African Americans (P = 0.002).

CONCLUSION

African Americans generally had worse pain, function, and performance prior to KA and worse scores after surgery, but differences were small and attenuated by ~25-50% after adjustment for potential confounding. Only WOMAC function scores showed clinically important postsurgical differences in adjusted analyses. Clinicians should be aware that after adjustment for potential confounders, African Americans have approximately equivalent outcomes compared to others, with the exception of WOMAC function score.

Top down or bottom up? An observational investigation of improvement in fibromyalgia symptoms following hip and knee replacement

OBJECTIVES

Many patients with osteoarthritis have comorbid symptoms of FM, but it is unknown how these symptoms respond to surgical procedures that address nociceptive input in the periphery, such as total joint replacement. Here we explore differences in clinical characteristics between patients whose FM symptoms do and do not improve following total hip or knee replacement.

METHODS

Participants were 150 patients undergoing knee or hip replacement who had a minimum FM survey score of 4 or greater prior to surgery. The top tertile of patients experiencing the most improvement in FM symptoms at month 6 were categorized as 'Improve' (n = 48) while the bottom two tertiles were categorized as 'Worsen/Same' (n = 102). Baseline symptom characteristics were compared between groups, as well as improvement in overall pain severity, surgical pain severity and physical function at 6 months.

RESULTS

The Worsen/Same group had higher levels of fatigue, depression and surgical site pain at baseline (all P < 0.05). Additionally, they improved less on overall pain severity and physical functioning 6 months after surgery (both P < 0.05).

CONCLUSION

Most patients derive significant benefit in improvement of comorbid FM symptoms following total joint replacement, but a substantial proportion do not. Understanding the neurobiological basis for these different trajectories may help inform clinical judgment and improve patient care.

Cost-Effectiveness of Diet and Exercise for Overweight and Obese Patients With Knee Osteoarthritis

OBJECTIVE

The Intensive Diet and Exercise for Arthritis (IDEA) trial showed that an intensive diet and exercise (D+E) program led to a mean 10.6-kg weight reduction and 51% pain reduction in patients with knee osteoarthritis (OA). The aim of the current study was to investigate the cost-effectiveness of adding this D+E program to treatment in overweight and obese (body mass index >27 kg/m² ) patients with knee OA.

METHODS

We used the Osteoarthritis Policy Model to estimate quality-adjusted life-years (QALYs) and lifetime costs for overweight and obese patients with knee OA, with and without the D+E program. We evaluated cost-effectiveness with the incremental cost-effectiveness ratio (ICER), a ratio of the differences in lifetime cost and QALYs between treatment strategies. We considered 3 cost-effectiveness thresholds: $50,000/QALY, $100,000/QALY, and $200,000/QALY. Analyses were conducted from health care sector and societal perspectives and used a lifetime horizon. Costs and QALYs were discounted at 3% per year. D+E characteristics were derived from the IDEA trial. Deterministic and probabilistic sensitivity analyses (PSAs) were used to evaluate parameter uncertainty and the effect of extending the duration of the D+E program.

RESULTS

In the base case, D+E led to 0.054 QALYs gained per person and cost $1,845 from the health care sector perspective and $1,624 from the societal perspective. This resulted in ICERs of $34,100/QALY and $30,000/QALY. In the health care sector perspective PSA, D+E had 58% and 100% likelihoods of being cost-effective with thresholds of $50,000/QALY and $100,000/QALY, respectively.

CONCLUSION

Adding D+E to usual care for overweight and obese patients with knee OA is cost-effective and should be implemented in clinical practice.

Utility of catastrophizing, body symptom diagram score and history of opioid use to predict future health care utilization after a primary care visit for musculoskeletal pain

BACKGROUND

Self-report information about pain and pain beliefs are often collected during initial consultation for musculoskeletal pain. These data may provide utility beyond the initial encounter, helping provide further insight into prognosis and long-term interactions of the patient with the health system.

OBJECTIVE

The aim of this study was to determine if pain catastrophizing and pain-related body symptoms can predict future health care utilization.

METHODS

This was a longitudinal cohort study. Baseline data were collected after receiving initial care for a musculoskeletal disorder in a multidisciplinary clinic within a large military hospital. Subjects completed the Pain Catastrophizing Scale, a region-specific disability measure, numeric pain rating scale and a body symptom diagram. Health care utilization data for 1 year prior and after the visit were extracted from the Military Health System Data Repository. Multivariable regression models appropriate for skewed and count data were developed to predict (i) musculoskeletal-specific medical visits, (ii) 12-month opioid use, (iii) musculoskeletal-specific medical costs and (iv) total medical costs. We investigated whether a pain catastrophizing × body symptom diagram interaction improved prediction, and developed separate models for opioid-naïve individuals and those with a history of opioid use in an exploratory analysis.

RESULTS

Pain catastrophizing but not body symptom diagram was a significant predictor of musculoskeletal visits, musculoskeletal costs and total medical costs. Exploratory analyses suggest these relationships are most robust for patients with a history of opioid use.

CONCLUSIONS

Pain catastrophizing can identify risk of high health care utilization and costs, even after controlling for common clinical variables. Addressing pain catastrophizing in the primary care setting may help to mitigate future health care utilization and costs, while improving clinical outcomes. These results provide direction for future validation studies in larger and more traditional primary care settings.

Characterizing the Use of Expectations in Orthopedic Surgery Research: A Scoping Review

Objective

Orthopedic literature on expectations is limited by lack of uniformity in how expectations are defined, conceptualized, and measured. Within this scoping review, we present a conceptual framework for understanding the construct of expectations and its derivatives (ie, expectation, expectancy, expectancies, etc) in studies of elective surgical orthopedic procedures. We also utilize this framework to map the current orthopedic surgery literature on expectations, highlighting its strengths, weaknesses, and gaps in its knowledge base.

Methods

We included articles that mentioned both expectations and one or more of 10 selected surgeries in their title or abstract. We focused on representative elective orthopedic surgeries that covered the body's major regions. We operationalized each study's individual expectation items into one of the expectation concept types within the presented conceptual model. We also extracted the name and type of expectations measurement tool used, whose expectations were measured, and descriptive information (eg, surgery type, publication date, country of origin, and study type).

Results

Ninety studies were included, with 70% published after 2008. A total of 64% investigated total knee and total hip arthroplasty, whereas 90% of studies investigated the expectations of patients, 5.6% investigated the expectations of physicians, and 4.4% investigated both. Of all studies, 72% utilized either study‐specific instruments with close‐ended, Likert‐type response formats or modifications of existing expectations questionnaires. Most studies focused on desirable, nontimeline‐related, treatment outcome expectations. Many studies aggregated multiple expectation results into a single score.

Conclusion

Adopting the standardized framework for expectations presented in this study will foster clearer communication and permit researchers to aggregate results across studies.

Identification of Functioning Domains in the Presurgical Period and Their Relationships with Opioid Use and Pain Catastrophizing

OBJECTIVES

The National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) is a multidimensional screening system evaluating biopsychosocial factors affecting pain and functioning. Using a military sample, the current study 1) examined the structure and domains of the PROMIS, the Defense and Veterans Pain Rating Scale 2.0 (DVPRS), and the Pain Catastrophizing Scale (PCS) within a presurgical setting and 2) examined the relationship of these variables to pre- and postsurgical opioid use.

METHODS

This cross-sectional study included 279 adult patients scheduled for surgery at the Walter Reed National Military Medical Center and a validation sample of 79 additional patients from the Naval Medical Center, San Diego. PROMIS, DVPRS, PCS, and opioid use data were collected before surgery. Exploratory factor analysis and confirmatory factor analysis identified the latent structure for the measures. A structural equation model (SEM) examined their relationship to pre- and postsurgical opioid use.

RESULTS

Two latent factors represented Psychosocial Functioning (PROMIS Depression, PROMIS Anxiety, and PROMIS Social Isolation) and Pain Impact (DVPRS, PROMIS Pain Interference, PROMIS Physical Functioning). The remaining PROMIS scales did not load onto a single factor. In the SEM, the two latent factors and PCS were significantly related to pre- and postsurgical opioid use.

CONCLUSIONS

This study highlights the utility and relative ease of using a convenient multidimensional assessment in presurgical settings. Using such an assessment can help provide targeted interventions for individuals who may be at greatest risk for negative postsurgical outcomes.

Pain Coping Skills Training for Patients Who Catastrophize About Pain Prior to Knee Arthroplasty: A Multisite Randomized Clinical Trial

BACKGROUND

Pain catastrophizing has been identified as a prognostic indicator of poor outcome following knee arthroplasty. Interventions to address pain catastrophizing, to our knowledge, have not been tested in patients undergoing knee arthroplasty. The purpose of this study was to determine whether pain coping skills training in persons with moderate to high pain catastrophizing undergoing knee arthroplasty improves outcomes 12 months postoperatively compared with usual care or arthritis education.

METHODS

A multicenter, 3-arm, single-blinded, randomized comparative effectiveness trial was performed involving 5 university-based medical centers in the United States. There were 402 randomized participants. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale, measured at baseline, 2 months, 6 months, and 12 months following the surgical procedure.

RESULTS

Participants were recruited from January 2013 to June 2016. In 402 participants, 66% were women and the mean age of the participants (and standard deviation) was 63.2 ± 8.0 years. Three hundred and forty-six participants (90% of those who underwent a surgical procedure) completed a 12-month follow-up. All 3 treatment groups had large improvements in 12-month WOMAC pain scores with no significant differences (p > 0.05) among the 3 treatment arms. No differences were found between WOMAC pain scores at 12 months for the pain coping skills and arthritis education groups (adjusted mean difference, 0.3 [95% confidence interval (CI), -0.9 to 1.5]) or between the pain coping and usual-care groups (adjusted mean difference, 0.4 [95% CI, -0.7 to 1.5]). Secondary outcomes also showed no significant differences (p > 0.05) among the 3 groups.

CONCLUSIONS

Among adults with pain catastrophizing undergoing knee arthroplasty, cognitive behaviorally based pain coping skills training did not confer pain or functional benefit beyond the large improvements achieved with usual surgical and postoperative care. Future research should develop interventions for the approximately 20% of patients undergoing knee arthroplasty who experience persistent function-limiting pain.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Knee replacement

Knee replacement surgery is one of the most commonly done and cost-effective musculoskeletal surgical procedures. The numbers of cases done continue to grow worldwide, with substantial variation in utilisation rates across regions and countries. The main indication for surgery remains painful knee osteoarthritis with reduced function and quality of life. The threshold for intervention is not well defined, and is influenced by many factors including patient and surgeon preference. Most patients have a very good clinical outcome after knee replacement, but multiple studies have reported that 20% or more of patients do not. So despite excellent long-term survivorship, more work is required to enhance this procedure and development is rightly focused on increasing the proportion of patients who have successful pain relief after surgery. Changing implant design has historically been a target for improving outcome, but there is greater recognition that improvements can be achieved by better implantation methods, avoiding complications, and improving perioperative care for patients, such as enhanced recovery programmes. New technologies are likely to advance future knee replacement care further, but their introduction must be regulated and monitored with greater rigour to ensure patient safety.

Predictive Factors for Developing Chronic Pain After Total Knee Arthroplasty

Total knee arthroplasty offers substantial improvements for patients as measured by functional status and quality of life; however, 8% to 34% of patients experience chronic postsurgical pain following surgery (CPSP). In addition to disruption in daily activities of life caused by the pain itself, CPSP has been associated with an overall reduction in quality of life following surgery. Risk factors for CPSP can be broadly defined as potentially modifiable or unlikely modifiable. Unlikely modifiable risks include gender, age, medical comorbidities, and socioeconomic status. Potentially modifiable risks include perioperative pain, physical function, psychological state, surgical factors, and possibly genomics. Understanding risks and the magnitude of their effect on outcomes such as CPSP is desirable because interventions designed to affect these factors may be able to dramatically improve outcomes.

Chronic pain after total knee arthroplasty

Despite a good outcome for many patients, approximately 20% of patients experience chronic pain after total knee arthroplasty (TKA).

Chronic pain after TKA can affect all dimensions of health-related quality of life, and is associated with functional limitations, pain-related distress, depression, poorer general health and social isolation.

In both clinical and research settings, the approach to assessing chronic pain after TKA needs to be in-depth and multidimensional to understand the characteristics and impact of this pain. Assessment of this pain has been inadequate in the past, but there are encouraging trends for increased use of validated patient-reported outcome measures.

Risk factors for chronic pain after TKA can be considered as those present before surgery, intraoperatively or in the acute postoperative period. Knowledge of risk factors is important to guide the development of interventions and to help to target care. Evaluations of preoperative interventions which optimize pain management and general health around the time of surgery are needed.

The causes of chronic pain after TKA are not yet fully understood, although research interest is growing and it is evident that this pain has a multifactorial aetiology, with a wide range of possible biological, surgical and psychosocial factors that can influence pain outcomes.

Treatment of chronic pain after TKA is challenging, and evaluation of combined treatments and individually targeted treatments matched to patient characteristics is advocated. To ensure that optimal care is provided to patients, the clinical- and cost-effectiveness of multidisciplinary and individualized interventions should be evaluated.

Cite this article: EFORT Open Rev 2018;3:461-470. DOI: 10.1302/2058-5241.3.180004

Predictors of Osteoarthritis Pain: the Importance of Resilience

PURPOSE OF REVIEW

Osteoarthritis (OA) is one of the most common and disabling forms of arthritis worldwide, with joint pain being a primary symptom. Given that clinical symptoms often show poor concordance with tissue damage in OA, processes other than joint remodeling likely play a role in the condition. Using the biopsychosocial model of pain as a guiding framework, the purpose of this review is to highlight the extra-articular mechanisms that contribute to pain and dysfunction in OA, with a specific focus on resilience.

RECENT FINDINGS

Whereas previous research has mostly focused on risk factors for worsening of OA pain, recently emerging evidence places greater emphasis on the identification of protective mechanisms that enhance pain adaptation and palliate the negative effects of joint pain. In view of this new and important research, more emphasis should be placed on endogenous pain modulation and, in particular, pain attenuation. The result of such work could serve as a basis for optimizing treatment in the OA population.

Construct validation and correlates of preoperative expectations of postsurgical recovery in persons undergoing knee replacement: baseline findings from a randomized clinical trial

Background

A patient’s recovery expectations prior to knee arthroplasty influence postsurgical outcome and satisfaction but a unidimensional measure of expectation has not been reported in the literature. Our primary purpose was to determine the extent to which a patient expectations scale reflects a unidimensional construct. Our second purpose was to identify pre-operative variables associated with patients’ expectations. We hypothesized that previously identified predictors of the latent expectation scale score would be associated with expectations and that previously unexplored variables of pain catastrophizing, depressive and anxiety symptoms, self-efficacy and number of painful body regions would also associate with pre-operative expectations.

Methods

Our randomized clinical trial had 384 patients assessed prior to knee replacement surgery. The expectations scale along with several predictor variables including WOMAC, psychological distress, and sociodemographic variables were obtained. Confirmatory factor analysis tested the unidimensionality of the measure and structural equation modeling identified predictors of the latent expectations measure.

Results

The expectations scale was found to be unidimensional with superior model fit (χ2 = 1.481; df = 2; p = 0.224; RMSEA = 0.035; 90% CI = [0–0.146]; CFI = 0.999; TLI = 0.993). The only variable significantly associated with expectations in the multivariate model was self-efficacy.

Conclusions

The expectations scale used in our study demonstrated unidimensionality and has strong potential for clinical application. Poor self-efficacy is a potential target for intervention given its independent association with expectation. Addressing expectations directly and indirectly through self-efficacy assessment may assist in better aligning patient’s expectations with likely outcome.

Trial registration

ClinicalTrials.gov NCT01620983.