Predictive value of quantitative sensory testing for acute and chronic postsurgical pain after total joint arthroplasty: a systematic review

Can quantitative sensory testing predict treatment outcomes in hip and knee osteoarthritis? A systematic review and meta-analysis of individual participant data

ABSTRACT

An individual participant data (IPD) meta-analysis can assess the predictive value of data on outcomes at the individual level, offering a potential tool for developing personalized pain management. Pretreatment quantitative sensory testing (QST) may stratify patient groups, which are then linked to treatment outcomes. Our objective was to determine if measures of QST at baseline are related to treatment outcomes (at any time point) for pain and disability in lower-limb osteoarthritis. We performed a systematic review with an IPD meta-analysis. Searches were conducted in 9 databases until May 5, 2023 for intervention studies that measured baseline QST and longitudinal measures of participant-reported pain and disability. We performed a 2-stage approach to analyse longitudinal data. Individual models were fitted to each study and combined using random effects multivariate meta-analytic models. Study quality was assessed using the Joanna Briggs Institute checklist, and certainty of the evidence was assessed using GRADE. We identified 3082 records and included 1 hip and 28 knee datasets consisting of 2522 participants from 40 studies. Local warm detection thresholds (P = 0.024) predicted knee osteoarthritis pain outcomes (very-low certainty). Local warm detection thresholds (P = 0.030), remote cold detection thresholds (P = 0.05), and remote pressure tolerance thresholds (P = 0.007) predicted knee osteoarthritis disability outcomes (very-low certainty). Other QST variables were associated with hip and knee osteoarthritis pain and disability levels (eg, pressure pain thresholds), but this relationship did not change over time. This review finds that mechanism-based, QST methodologies do not consistently predict pain or disability on an individual level in hip or knee osteoarthritis.

Effectiveness of oral vs intravenous acetaminophen on pain management following total joint arthroplasty: A systematic review and meta-analysis

BACKGROUND

In the management of postoperative pain following total joint arthroplasty (TJA), the use of nonsteroidal anti-inflammatory drugs, including acetaminophen, plays a key role in alleviating pain. However, the comparison between intravenous and oral acetaminophen administration in patients undergoing full joint replacement surgery remains controversial.

AIM

To assess the effectiveness of intravenous and oral acetaminophen in alleviating pain and supporting rehabilitation following TJA.

METHODS

PubMed, Embase and the Cochrane Library were comprehensively searched to identify cohort studies. The effects of intravenous and oral acetaminophen for managing pain and supporting rehabilitation following TJA were analysed using randomized controlled trials. PRISMA guidelines were followed. The effectiveness of the administration routes was compared based on visual analogue scale (VAS) scores at 24 and 48 h, total morphine usage within 24 h, and total duration of hospital stay.

RESULTS

The meta-analysis included seven studies comparing intravenous acetaminophen groups and oral acetaminophen groups. The results demonstrated that oral acetaminophen was comparable to intravenous acetaminophen with regard to VAS scores at 24 h and 48 h (P = 0.76 and 0.08, respectively). The difference in total morphine use between the two groups was not significant (P = 0.22). However, the total hospital stay duration of the intravenous acetaminophen groups was significantly reduced compared to the oral acetaminophen groups (P = 0.0005), showing significant advantages in optimizing postoperative recovery and shortening hospitalisation time.

CONCLUSION

After TJA surgery, intravenous injection of acetaminophen can shorten hospitalisation time and is suitable for rapid analgesia, Oral administration has become the preferred choice for mild cases due to its convenience and economy, providing a basis for clinical drug selection.

Utility of the Patient-Reported Outcomes Measurement Information System Global Mental Health T-Score to Identify Patients at Risk for Poor Postsurgical Outcomes Following Total Hip Arthroplasty

BACKGROUND

Mental illness is a known risk factor for poor postoperative outcomes following total hip arthroplasty (THA); however, the relationship between a patients overall mental health and recovery from THA is not as well established. Using the preoperative Patient-Reported Outcomes Measurement Information System (PROMIS-10) Mental Health Subdomain T-Score (MHT), the purpose of this study was to understand the association between mental health and postoperative outcomes up to one year following THA.

METHODS

This was a retrospective chart review of patients undergoing elective primary THA. Patients who did not have a formal diagnosis of a mental illness condition were divided based on their MHT (above average [AA] > 50, average 40 to 50, below average [BA] < 40). Postsurgical parameters included inpatient opioid consumption and patient satisfaction, and 1-year postsurgery self-reported pain and patient-reported outcomes scores. A total of 972 patients were included in this study (AA 61.2%, average 33.1%, BA 5.7%).

RESULTS

After controlling for confounders, multivariate models demonstrated that the MHT was an independent predictor of pain, opioid consumption, patient-reported outcomes, and satisfaction. Patients in the AA group overall demonstrated better outcomes and required fewer opioids than those in the BA group.

CONCLUSIONS

The MHT can be used as a preoperative screening tool that can identify an at-risk group that has not been previously described. An MHT < 40 was associated with poor postoperative outcomes, increased pain and opioid consumption, and lower overall satisfaction scores.

Predictors of subacute postoperative pain after total knee arthroplasty: A secondary analysis of two randomized trials

BACKGROUND

Methods for identifying high-pain responders undergoing total knee arthroplasty remain important to improve individualized pain management. This study aimed at evaluating pre- and perioperative predictors of pain on Days 2-7 after total knee arthroplasty.

METHODS

This is a secondary analysis of data from 227 patients participating in two randomized trials. Pain outcomes were mean pain during walking on Days 2-7 and on Days 2, 4 and 7. Multivariable linear and logistic regressions were carried out in two steps. First, only preoperative available variables including demographics, comorbidities, pain catastrophizing scale and preoperative pain were evaluated while controlling for trial intervention and recruitment site. In the second step, perioperative variables and pain during walking 24 h postoperatively were added.

RESULTS

The model with only preoperative predictors for mean pain Days 2-7 showed preoperative pain (R-squared 0.097) as the only predictor. In the second model, adding postoperative available variables, only pain 24 h postoperatively (R-squared 0.248) was significant, with a significant main effect of recruitment site. Results for the separate day analysis similarly showed preoperative pain and pain during walking 24 h postoperatively as predictors. The overall best sensitivity (60%) and specificity (74%) for predicting a high-subacute postoperative pain response on Days 2-7 was with cut-off values of VAS 45.5 (out of 100) for pain during walking 24 h postoperatively.

CONCLUSIONS

Postoperative pain during walking at 24 h is predictive of subacute postoperative pain on Days 2-7 after total knee arthroplasty, while preoperative pain was only a weak predictor.

SIGNIFICANCE STATEMENT

This study investigated factors associated with pain after total knee arthroplasty beyond the immediate postoperative period. The analysis revealed significant associations between preoperative pain levels and, particularly, pain 24 h postoperatively, with subsequent subacute pain the following week. These findings can assist in identifying patients who would benefit from enhanced, individualized analgesic interventions to facilitate postoperative recovery.

Preoperative glycaemic control, number of pain locations, structural knee damage, self-reported central sensitisation, satisfaction and personal control are predictive of 1-year postoperative pain, and change in pain from pre- to 1-year posttotal knee arthroplasty

PURPOSE

The aim of this study was to identify preoperative predictors for 1-year posttotal knee arthroplasty (TKA) pain and pre- to post-TKA pain difference in knee osteoarthritis (KOA) patients.

METHODS

From March 2018 to July 2023, this prospective longitudinal cohort study enrolled KOA patients awaiting TKA from four hospitals in Belgium and the Netherlands. Different biopsychosocial predictors were assessed preoperatively by questionnaires and physical examinations (input variables). The Knee injury and Osteoarthritis Outcome Score (KOOS) subscale pain was used to measure pain intensity. The absolute KOOS subscale pain score 1-year post-TKA and the difference score (ΔKOOS = 1-year postoperative - preoperative) were used as primary outcome measures (output variables). Two multivariable linear regression analyses were performed.

RESULTS

Two hundred and twenty-three participants were included after multiple imputation. Worse absolute KOOS subscale pain scores 1-year post-TKA and negative or closer to zero ΔKOOS subscale pain scores were predicted by self-reported central sensitisation, lower KOA grade and preoperative satisfaction, and higher glycated haemoglobin, number of pain locations and personal control (adjusted R2 = 0.25). Additional predictors of negative or closer to zero ΔKOOS subscale pain scores were being self-employed, higher preoperative pain and function (adjusted R2 = 0.37).

CONCLUSION

This study reports different biopsychosocial predictors for both outcomes that have filtered out other potential predictors and provide value for future studies on developing risk assessment tools for the prediction of chronic TKA pain.

PROTOCOL REGISTRATION

The protocol is registered at clinicaltrials.gov (NCT05380648) on 13 May 2022.

LEVEL OF EVIDENCE

Level II.

The PROMIS-10 Mental Health T-Score: An Independent Predictor of Recovery for Up to 1 Year After Elective Lumbar Spine Fusion

STUDY DESIGN

Retrospective comparative cohort.

OBJECTIVE

Investigate how mental health, as measured by the PROMIS-10 Global Mental Health T-Score (MHT), influences a patient's recovery up to 1 year after elective lumbar fusion.

SUMMARY OF BACKGROUND DATA

Patients with mental health concerns in need of lumbar fusions have increased. Evidence suggests that mental disorders influence a patient's postoperative recovery; however, there is a paucity of information detailing the association between mental health and outcomes.

METHODS

A total of 351 patients who underwent 1- or 2-level elective lumbar fusion between April 2020 and June 2023 and completed all follow-up evaluations for up to 1 year postfusion were analyzed for this study. Patients were stratified by their MHT score (above average [AA] >50, average [A] 40-50, below average [BA] <40), regardless of mental illness diagnosis. Outcome measures including pain at hospital discharge and 3, 6, and 12 months after fusion, patient satisfaction, and the Oswestry Disability Index (ODI) score at 3, 6, and 12 months after fusion were compared among groups.

RESULTS

Nearly 20% of patients reported below-average mental health during their preoperative evaluation. After controlling for confounders, findings suggested that patients in the [BA] group reported 2 pain levels higher than the [AA] group at each time point and 1 point higher than the [A] group. Patients in the [BA] group performed worse on the ODI at all-time points compared with the other study groups. Patients in the [AA] group were 3 times more likely to be satisfied with their outcomes compared with the [BA] group.

CONCLUSION

The MHT was an independent predictor of pain, satisfaction, and ODI scores for up to 1 year post-fusion, while a mental disorder diagnosis was not. An MHT score below 40 may be a risk factor for patients undergoing elective lumbar fusion.

Preoperative pain sensitivity and its correlation with postoperative acute and chronic pain: a systematic review and meta-analysis

BACKGROUND

Preoperative pain sensitivity (PPS) can be associated with postsurgical pain. However, estimates of this association are scarce. Confirming this correlation is essential to identifying patients at high risk for severe postoperative pain and for developing analgesic strategy. This systematic review and meta-analysis summarises PPS and assessed its correlation with postoperative pain.

METHODS

PubMed, Scopus, Cochrane Library, and PsycINFO were searched up to October 1, 2023, for studies reporting the association between PPS and postsurgical pain. Two authors abstracted estimates of the effect of each method independently. A random-effects model was used to combine data. Subgroup analyses were performed to investigate the effect of pain types and surgical procedures on outcomes.

RESULTS

A total of 70 prospective observational studies were included. A meta-analysis of 50 studies was performed. Postoperative pain was negatively associated with pressure pain threshold (PPT; r=-0.15, 95% confidence interval [CI] -0.23 to -0.07]) and electrical pain threshold (EPT; r=-0.28, 95% CI -0.42 to -0.14), but positively correlated with temporal summation of pain (TSP; r=0.21, 95% CI 0.12-0.30) and Pain Sensitivity Questionnaire (PSQ; r=0.25, 95% CI 0.13-0.37). Subgroup analysis showed that only TSP was associated with acute and chronic postoperative pain, whereas PPT, EPT, and PSQ were only associated with acute pain. A multilevel (three-level) meta-analysis showed that PSQ was not associated with postoperative pain.

CONCLUSIONS

Lower PPT and EPT, and higher TSP are associated with acute postoperative pain while only TSP is associated with chronic postoperative pain. Patients with abnormal preoperative pain sensitivity should be identified by clinicians to adopt early interventions for effective analgesia.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023465727).

Prognostic value of preoperative mechanical hyperalgesia and neuropathic pain qualities for postoperative pain after total knee replacement

BACKGROUND

Total knee replacement (TKR) is the gold standard treatment for end-stage chronic osteoarthritis pain, yet many patients report chronic postoperative pain after TKR. The search for preoperative predictors for chronic postoperative pain following TKR has been studied with inconsistent findings.

METHODS

This study investigates the predictive value of quantitative sensory testing (QST) and PainDETECT for postoperative pain 3, 6 and 12 months post-TKR. We assessed preoperative and postoperative (3 and 6 months) QST measures in 77 patients with knee OA (KOA) and 41 healthy controls, along with neuropathic pain scores in patients (PainDETECT). QST parameters included pressure pain pressure threshold (PPT), pain tolerance threshold (PTT), conditioned pain modulation (CPM) and temporal summation (TS) using cuff algometry, alongside mechanical hyperalgesia and temporal summation to repeated pinprick stimulation.

RESULTS

Compared to healthy controls, KOA patients at baseline demonstrated hyperalgesia to pinprick stimulation at the medial knee undergoing TKR, and cuff pressure at the calf. Lower cuff algometry PTT and mechanical pinprick hyperalgesia were associated with preoperative KOA pain intensity. Moreover, preoperative pinprick pain hyperalgesia explained 25% of variance in pain intensity 12 months post-TKR and preoperative neuropathic pain scores also captured 30% and 20% of the variance in postoperative pain at 6 and 12 months respectively. A decrease in mechanical pinprick hyperalgesia from before surgery to 3 months after TKR was associated with lower postoperative pain at the 12 months post-TKR follow-up.

CONCLUSION

Our findings suggest that preoperative pinprick hyperalgesia and neuropathic-like pain symptoms show predictive value for the development of chronic post-TKR pain.

SIGNIFICANCE STATEMENT

This study's findings hold significant implications for chronic pain management in knee osteoarthritis patients, particularly those undergoing total knee replacement surgery (TKR). Mechanical hyperalgesia and neuropathic pain-like characteristics predict postoperative pain 1 year after TKR, emphasizing the importance of understanding pain phenotypes in OA for selecting appropriate pain management strategies. The normalization of hyperalgesia after surgery correlates with better long-term outcomes, further highlighting the therapeutic potential of addressing abnormal pain processing mechanisms pre- and post-TKR.

Mechanical hyperalgesia and neuropathic pain qualities impart risk for chronic postoperative pain after total knee replacement

Total knee replacement (TKR) is the gold-standard treatment for end-stage chronic osteoarthritis pain, yet many patients report chronic postoperative pain after TKR. The search for preoperative predictors for chronic postoperative pain following TKR has been studied with inconsistent findings. This study investigates the predictive value of quantitative sensory testing (QST) and PainDETECT for postoperative pain 3, 6, and 12 months post-TKR. We assessed baseline and postoperative (3- and 6-months) QST measures in 77 patients with knee OA (KOA) and 41 healthy controls, along with neuropathic pain scores in patients (PainDETECT). QST parameters included pressure pain pressure threshold (PPT), pain tolerance threshold (PTT), conditioned pain modulation (CPM), and temporal summation (TS) using cuff algometry, alongside mechanical hyperalgesia, and mechanical temporal summation to repeated pinprick stimulation. Compared to healthy controls, KOA patients at baseline demonstrated hyperalgesia to pinprick stimulation at the medial OA-affected knee and cuff pressure on the ipsilateral calf. Lower cuff algometry PTT and mechanical pinprick hyperalgesia were associated with baseline KOA pain intensity. Moreover, baseline pinprick pain hyperalgesia explained 25% of variance in pain intensity 12 months post-TKR and preoperative neuropathic pain scores also captured 30% and 20% of the variance in postoperative pain at 6- and 12-months, respectively. A decrease in mechanical pinprick hyperalgesia from before surgery to 3 months after TKR was associated with lower postoperative pain at the 12 months post-TKR follow-up, and vice-versa. Our findings suggest that preoperative pinprick hyperalgesia and PainDETECT neuropathic-like pain symptoms show predictive value for the development of chronic post-TKR pain.

Sex moderates the association between quantitative sensory testing and acute and chronic pain after total knee/hip arthroplasty

OBJECTIVES

Acute postsurgical pain (APSP) may persist over time and become chronic. Research on predictors for APSP and chronic postsurgical pain (CPSP) has produced inconsistent results. This observational study aimed to analyze psychological and psychophysical variables associated with APSP and CPSP after total knee or hip arthroplasty, and to explore the role of sex.

METHODS

Assessments were conducted before surgery, 48 h, and 3 months postsurgery, including questionnaires (sociodemographic, pain related, and psychological) and quantitative sensory testing (QST). Hierarchical linear regression models analyzed potential predictors of APSP and CPSP, and moderation analyses evaluated the role of sex.

RESULTS

The study included 63 participants undergoing total knee (34, 54%) or hip (29, 46%) arthroplasty. Thirty-one (49.2%) were female and 32 (50.8%) were male. APSP (48 h) was associated with impaired conditioned pain modulation (CPM) (β = 0.301, p = 0.019). CPSP (3 months) was associated with being female (β = 0.282, p = 0.029), longer presurgical pain duration (β = 0.353, p = 0.006), knee arthroplasty (β = -0.312, p = 0.015), higher APSP intensity (β = 373, p = 0.004), and impaired CPM (β = 0.126, p = 0.004). In multivariate analysis, these clinical variables were significant predictors of CPSP, unlike sex, and CPM (adj. R 2 = 0.349). Moderation analyses showed that wind-up ratio (WUR) was a significant predictor of APSP in men (WUR × sex: b = -1.373, p = 0.046) and CPM was a significant predictor of CPSP in women (CPM × sex: b = 1.625, p = 0.016).

CONCLUSIONS

Specific QST parameters could identify patients at risk for high-intensity APSP and CPSP, with sex as a moderator. This has important clinical implications for patient care, paving the way for developing tailored preventive pain management strategies.

Psychological predictors of acute postoperative pain after total knee and hip arthroplasty: A systematic review

BACKGROUND

Identifying patients at high risk of acute postoperative pain after total knee or hip arthroplasty (TKA/THA) will facilitate individualized pain management and research on the efficacy of treatment options. Numerous studies have reported that psychological patient factors may influence acute postoperative pain, but most reviews have focused on chronic pain and functional outcomes. This systematic review aims to evaluate which psychological metrics are associated with acute postoperative pain after TKA and THA.

METHODS

A systematic search was conducted using the databases PubMed, EMBASE, Web of Science, and Cochrane Library until June 2022. Full-text articles reporting associations of preoperative psychological factors with acute pain within 48 h of TKA or THA surgery were identified. Quality was assessed using the Quality in Prognostic Studies tool.

RESULTS

Eighteen studies containing 16 unique study populations were included. TKA was the most common procedure, and anxiety and depression were the most evaluated psychological metrics. Several different anesthetic techniques and analgesic regimens were used. The studies were generally rated as having a low to moderate risk of bias. Catastrophizing was associated with acute pain in six studies (of nine), mainly after TKA. In contrast, three studies (of 13) and two studies (of 13) found anxiety and depression, respectively, to be associated with acute postoperative pain.

CONCLUSION

Pain catastrophizing seemed to be the most consistent psychological predictor of acute postoperative pain after TKA. The results for other psychological factors and THA were inconsistent. However, the interpretation of results was limited by considerable methodological heterogeneity.

Quantitative sensory testing in a magnetic resonance environment: considerations for thermal sensitivity and patient safety

Introduction

Quantitative sensory testing (QST) is often used to understand the perceptual basis of acute and chronic conditions, including pain. As the need grows for developing a mechanistic understanding of neurological pathways underlying perception in the basic and clinical sciences, there is a greater need to adapt techniques such as QST to the magnetic resonance (MR) environment. No studies have yet evaluated the impact of the MR environment on the perception of thermal stimuli. This study aimed to evaluate the differences in temperature sensitivity outside an MR environment and during an MRI scanning session. We hypothesized that there would be a difference in how participants reported their pain sensitivity between the two environments.

Methods

Healthy participants underwent thermal QST outside the MR scanning environment, where they were asked to rate the temperature of a noxious stimulus at which they perceived their pain to be 7/10, using a Likert scale ranging from 0 to 10. Participants repeated this procedure inside a 3.0 T MRI approximately 30 min later. We repeated our investigation in a clinical cohort of participants with a chronic pain condition.

Results

There were statistically significant changes of 1.1°C in thermal sensitivity between environments. This increase in pain threshold was found in healthy participants and replicated in the clinical cohort.

Discussion

Findings can be applied toward improving MR safety, the resolution of brain pathways underlying pain mechanisms, and to more broadly comment on the impact of the MR environment on investigations that integrate perception-influenced processes.

The mechanisms and management of persistent postsurgical pain

An estimated 10%-50% of patients undergoing a surgical intervention will develop persistent postsurgical pain (PPP) lasting more than 3 months despite adequate acute pain management and the availability of minimally invasive procedures. The link between early and late pain outcomes for surgical procedures remains unclear-some patients improve while others develop persistent pain. The elective nature of a surgical procedure offers a unique opportunity for prophylactic or early intervention to prevent the development of PPP and improve our understanding of its associated risk factors, such as pre-operative anxiety and the duration of severe acute postoperative pain. Current perioperative pain management strategies often include opioids, but long-term consumption can lead to tolerance, addiction, opioid-induced hyperalgesia, and death. Pre-clinical models provide the opportunity to dissect mechanisms underpinning the transition from acute to chronic, or persistent, postsurgical pain. This review highlights putative mechanisms of PPP, including sensitisation of peripheral sensory neurons, neuroplasticity in the central nervous system and nociceptive signalling along the neuro-immune axis.

Evolution of somatosensory processing signs after nociceptive targeted surgery in patients with musculoskeletal disorders: a systematic review

ABSTRACT

Surgery is often advised when conservative treatment fails in musculoskeletal pain conditions, but a substantial proportion still suffers chronic pain after surgery. Somatosensory processing system (SPS) signs were previously studied as potential predictors for chronic postsurgical pain, but results are inconsistent. Therefore, studying the evolution of SPS signs could be of added value. The aim was to summarize all studies that measured how SPS signs evolved after nociceptive targeted surgery in musculoskeletal disorders and to find preoperative, perioperative, and postoperative predictors for the evolution of these SPS signs. Data were summarized, and risk of bias and level of evidence and recommendation were determined. Twenty-one studies were included. Five scored a low, 3 a moderate, and 13 a high risk of bias. In general, no consistent evolution of SPS signs comparing preoperative and postoperative values and predictors for this evolution in musculoskeletal disorders could be found. In most cases, static quantitative sensory testing (QST) did not change or conflicting results were found. On the other hand, dynamic QST mostly improved after surgery. Worthfully mentioning is that worsening of SPS signs was only seen at a follow-up of <3 months after surgery, that conclusions are stronger when evaluating dynamic QST with a follow-up of ≥3 months after surgery, and that pain improvement postsurgery was an important predictor. Future high-quality research should focus on the evolution of SPS signs after nociceptive targeted surgery, accounting for pain improvement groups and focusing on preoperative, perioperative, and postoperative predictors of this evolution.

Feasibility and reliability of a quantitative sensory testing protocol in youth with acute musculoskeletal pain postsurgery or postinjury

ABSTRACT

Quantitative sensory testing (QST) is increasingly used in pediatric chronic pain; however, assessment in youth with acute musculoskeletal (MSK) pain is limited. This study evaluated the feasibility, reliability, and sources of variability of a brief QST protocol in 2 clinical samples of youth with acute MSK pain. Participants were 277 youth (M age = 14.5 years, SD = 2.0, range = 11-18 years, 59% female, 81% non-Hispanic) across 3 geographic study sites who completed a QST protocol assessing pressure and thermal pain sensitivity, temporal summation of pain, and conditioned pain modulation 8 weeks after MSK surgery (n = 100) or within 4 weeks after an acute MSK injury (n = 177). High feasibility was demonstrated by protocol completion rates ranging from 97.5% to 100% for each task, with 95.3% of youth completing all tasks. Reliability was high, with reliability coefficients of >0.97 for 7 out of 8 QST parameters and minimal influence of examiner or participating site effects. Younger youth had lower pressure and heat pain thresholds (11-12 vs 13-18 years, d = -0.80 to -0.56) and cold pain tolerance (d = -0.33). Hispanic youth had higher pressure and heat pain thresholds (d = 0.37-0.45) and pain ratings for cold pain tolerance (d = 0.54) compared with non-Hispanic youth. No significant differences were observed in QST values by sex or personal contextual factors at the time of assessment (momentary pain, menstrual period, use of pain medications). Overall findings demonstrate feasibility of a brief QST protocol with youth with diverse acute MSK pain and data provide initial support for the reliability of this QST protocol for multisite research studies.

Quantitative sensory testing as an assessment tool to predict the response to standard pain treatment in knee osteoarthritis: a systematic review and meta-analysis

Emerging evidence suggest that quantitative sensory testing (QST) may predict the treatment response to pain-relieving therapies. This systematic review and meta-analysis focus on the predictive value of QST for pain management of knee osteoarthritis (OA). MEDLINE and EMBASE were systematically searched for all studies from year 2000 to 2023 on pretreatment QST and treatment of OA including surgical, pharmaceutical, and nonsurgical and nonpharmaceutical therapies. Preclinical studies and reviews were excluded. The systematic review followed the PRISMA guidelines and was pre-registered on the Open Science Framework website (link: https://osf.io/4FETK/, Identifier: DOI 10.17605/OSF.IO/4FETK). Meta-analysis were conducted to demonstrate the strength of the pre-treatment QST predictions on pain outcomes after OA treatments. Sixteen surgical (all on total knee arthroplasty [TKA], N = 1967), 5 pharmaceutical (4 on non-steroidal anti-inflammatory drugs [NSAIDs], N = 271), and 4 exercise-based therapy studies (N = 232) were identified. Pretreatment QST parameters predicted pain-relieving treatment outcomes in 81% of surgical, 100% of pharmaceutical, and 50% of exercise-based therapy studies. Meta-analyses found pretreatment QST profiles to predicted pain outcomes after TKA (random effects: 0.309, 95% confidence interval [CI]: 0.206-0.405, P < 0.001), NSAIDs (random effects: 0.323, 95% CI: 0.194-0.441, P < 0.001), and exercise-based therapies (random effects: 0.417, 95% CI: 0.138-0.635, P = 0.004). The overall risk of bias for the included studies was low to moderate. This systematic review and meta-analysis demonstrate weak-to-moderate associations between pretreatment QST and pain outcomes after standard OA pain treatments. Based on this work, it is hypothesized that a subset of specific pain sensitive patients with OA exist and that these patients do not respond adequately to standard OA pain treatments.

Outcomes of a QST Protocol in Healthy Subjects and Chronic Pain Patients: A Controlled Clinical Trial

Chronic pain is an important cause of disability with a high burden to society. Quantitative sensory testing (QST) is a noninvasive multimodal method used to discriminate the function of nerve fibers. The aim of this study is to propose a new, reproducible, and less time-consuming thermal QST protocol to help characterize and monitor pain. Additionally, this study also compared QST outcomes between healthy and chronic pain subjects. Forty healthy young/adult medical students and fifty adult/elderly chronic pain patients were evaluated in individual sessions including pain history, followed by QST assessments divided into three proposed tests: pain threshold, suprathreshold, and tonic pain. In the chronic pain group, a significantly higher pain threshold (hypoesthesia) and a higher pain sensibility (hyperalgesia) were demonstrated at threshold temperature when compared to healthy participants. The sensitivity to the suprathreshold and tonic stimulus did not prove to be significantly different between both groups. The main results demonstrated that the heat threshold QST tests can be helpful in evaluating hypoesthesia and that the sensitivity threshold temperature test can demonstrate hyperalgesia in individuals with chronic pain. In conclusion, this study demonstrates the importance of using tools such as QST as a complement to detect changes in several pain dimensions.