The natural history of pain and neuropathic pain after knee replacement: a prospective cohort study of the point prevalence of pain and neuropathic pain to a minimum three-year follow-up

Prevalence and patterns of neuropathic pain in people with chronic post-surgical pain after total knee arthroplasty

Aims

The aim of this study was to describe the prevalence and patterns of neuropathic pain over one year in a cohort of patients with chronic post-surgical pain at three months following total knee arthroplasty (TKA).

Methods

Between 2016 and 2019, 363 patients with troublesome pain, defined as a score of ≤ 14 on the Oxford Knee Score pain subscale, three months after TKA from eight UK NHS hospitals, were recruited into the Support and Treatment After Replacement (STAR) clinical trial. Self-reported neuropathic pain and postoperative pain was assessed at three, nine, and 15 months after surgery using the painDETECT and Douleur Neuropathique 4 (DN4) questionnaires collected by postal survey.

Results

Symptoms of neuropathic pain were common among patients reporting chronic pain at three months post-TKA, with half reporting neuropathic pain on painDETECT (191/363; 53%) and 74% (267/359) on DN4. Of those with neuropathic pain at three months, half continued to have symptoms over the next 12 months (148/262; 56%), one-quarter had improved (67/262; 26%), and for one-tenth their neuropathic symptoms fluctuated over time (24/262; 9%). However, a subgroup of participants reported new, late onset neuropathic symptoms (23/262; 9%). Prevalence of neuropathic symptoms was similar between the screening tools when the lower cut-off painDETECT score (≥ 13) was applied. Overall, mean neuropathic pain scores improved between three and 15 months after TKA.

Conclusion

Neuropathic pain is common in patients with chronic pain at three months after TKA. Although neuropathic symptoms improved over time, up to half continued to report painful neuropathic symptoms at 15 months after TKA. Postoperative care should include screening, assessment, and treatment of neuropathic pain in patients with early chronic postoperative pain after TKA.

The protective effects of orexin-A in alleviating cell senescence against interleukin-1β (IL-1β) in chondrocytes

Osteoarthritis (OA) is one of the most important causes of global disability, and dysfunction of chondrocytes is an important risk factor. The treatment of OA is still a challenge. Orexin-A is a hypothalamic peptide, and its effects in OA are unknown. In this study, we found that exposure to interleukin-1β (IL-1β) reduced the expression of orexin-2R, the receptor of orexin-A in TC-28a2 chondrocytes. Importantly, the senescence-associated β-galactosidase (SA-β-gal) staining assay demonstrated that orexin-A treatment ameliorates IL-1β-induced cellular senescence. Importantly, the presence of IL-1β significantly reduced the telomerase activity of TC-28a2 chondrocytes, which was rescued by orexin-A. We also found that orexin-A prevented IL-1β-induced increase in the levels of Acetyl-p53 and the expression of p21. It is shown that orexin-A mitigates IL-1β-induced reduction of sirtuin 3 (SIRT3). Silencing of SIRT3 abolished the protective effects of orexin-A against IL-1β-induced cellular senescence. These results imply that orexin-A might serve as a promising therapeutic agent for OA.

Peripheral nerve stimulation for chronic knee pain following total knee arthroplasty: a systematic review

Chronic knee pain following total knee arthroplasty (TKA) affects a subset of patients that is refractory to pharmacological and non-pharmacological modalities. Peripheral nerve stimulation (PNS) has been used in patients with chronic knee pain following TKA and has shown some efficacy. Methods: Comprehensive search of Ovid Medline, Elsevier Embase, Cochrane Central Register of Controlled Trials, CINAHL Plus with Full Text, Scopus, SPORTDiscus with Full Text and the Web of Science platform. From inception to August 2022, for studies using PNS to treat chronic knee pain following TKA. Primary outcomes included pain scores, functional status and medication usage. Results: Nine studies were extrapolated with all demonstrating effectiveness of PNS for patients with chronic knee pain following TKA. Discussion: PNS for chronic knee pain following TKA has been shown to be an efficacious treatment modality. The level of evidence is low and more research is needed to assess its safety and effectiveness.

Effectiveness of Geniculate Artery Embolization for Chronic Pain after Total Knee Replacement-A Pilot Study

PURPOSE

To evaluate the efficacy and safety of embolization of hyperemic synovial tissue for the treatment of persistent pain after total knee arthroplasty (TKA).

MATERIALS AND METHODS

Twelve patients with persistent pain after TKA were enrolled in this prospective, single-center pilot study. Genicular artery embolization (GAE) was performed using 75-μm spherical particles. The patients were assessed using a 100-point Visual Analog Scale (VAS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) at baseline and 3 and 6 months thereafter. Adverse events were recorded at all time points.

RESULTS

A mean of 1.8 ± 0.8 abnormal hyperemic genicular arteries were identified and embolized, with a median volume of diluted embolic material of 4.3 mL in all 12 (100%) patients. The mean VAS score on walking improved from 73 ± 16 at baseline to 38 ± 35 at the 6-month follow-up (P < .05). The mean KOOS pain score improved from 43.6 ± 15.5 at baseline to 64.6 ± 27.1 at the 6-month follow-up (P < .05). At the 6-month follow-up, 55% and 73% of the patients attained a minimal clinically important change in pain and quality of life, respectively. Self-limited skin discoloration occurred in 5 (42%) patients. The VAS score increased by more than 20 immediately after embolization in 4 (30%) patients, who required analgesic treatment for 1 week.

CONCLUSION

GAE is a safe method of treating persistent pain after TKA that demonstrates potential efficacy at 12 months.

Neuropathic Pain Associated With First Metatarsophalangeal Joint Osteoarthritis: Frequency and Associated Factors

OBJECTIVE

To determine whether neuropathic pain is a feature of first metatarsophalangeal (MTP) joint osteoarthritis (OA).

METHODS

A total of 98 participants (mean ± SD age 57.4 ± 10.3 years) with symptomatic radiographic first MTP joint OA completed the PainDETECT questionnaire (PD-Q), which has 9 questions regarding the intensity and quality of pain. The likelihood of neuropathic pain was determined using established PD-Q cutoff points. Participants with unlikely neuropathic pain were then compared to those with possible/likely neuropathic pain in relation to age, sex, general health (Short Form 12 [SF-12] health survey), psychological well-being (Depression, Anxiety and Stress Scale), pain characteristics (self-efficacy, duration, and severity), foot health (Foot Health Status Questionnaire [FHSQ]), first MTP dorsiflexion range of motion, and radiographic severity. Effect sizes (Cohen's d coefficient) were also calculated.

RESULTS

A total of 30 (31%) participants had possible/likely neuropathic pain (19 possible [19.4%], 11 likely [11.2%]). The most common neuropathic symptoms were sensitivity to pressure (56%), sudden pain attacks/electric shocks (36%) and burning (24%). Compared to those with unlikely neuropathic pain, those with possible/likely neuropathic pain were significantly older (d = 0.59, P = 0.010), had worse SF-12 physical scores (d = 1.10, P < 0.001), pain self-efficacy scores (d = 0.98, P < 0.001), FHSQ pain scores (d = 0.98, P < 0.001), and FHSQ function scores (d = 0.82, P < 0.001), and had higher pain severity at rest (d = 1.01, P < 0.001).

CONCLUSION

A significant proportion of individuals with first MTP joint OA report symptoms suggestive of neuropathic pain, which may partly explain the suboptimal responses to commonly used treatments for this condition. Screening for neuropathic pain may be useful in the selection of targeted interventions and may improve clinical outcomes.

Trajectory of chronic and neuropathic pain, anxiety and depressive symptoms and pain catastrophizing after total knee replacement. Results of a prospective, single-center study at a mean follow-up of 7.5 years

INTRODUCTION

A considerable number of patients are not satisfied after total knee replacement (TKR) because of persistent pain. This pain can also be neuropathic in origin. Both types of pain have a large impact on function and quality of life. Furthermore, the trajectory of anxiety and depressive symptoms and pain catastrophizing has rarely been studied after TKR surgery. The primary objective of this study was to define the trajectory of knee pain after primary TKR. The secondary objectives were to evaluate how neuropathic pain, anxiety and depressive symptoms and pain catastrophizing change over time.

METHODS

This prospective, single-center study included patients who underwent primary TKR for primary osteoarthritis between July 2011 and December 2012. Personal data (age, sex, body mass index, knee history, operated side, surgical approach, type of implant, operative time, and rehabilitation course) and the responses to seven questionnaires (Numerical pain rating scale, DN4-interview for neuropathic pain, Oxford Knee Scale, Hospital and Anxiety Depression Scale, Beck Depression Inventory, Patient Catastrophizing Scale and Brief Pain Inventory) were determined preoperatively, at 6 months postoperative and at a mean follow-up of 7.5 years.

RESULTS

Preoperatively, 129 patients (35 men, 94 women) filled out all the questionnaires. Subsequently, 32 patients were excluded because of incomplete responses at 6 months postoperative, 6 were excluded because they had undergone revision surgery, 11 patients were lost to follow-up and 5 patients had died. In the end, 65 patients were available for analysis (50% of the initial cohort) who were 74 years old on average at inclusion. Between the preoperative period and 6 months postoperative, pain (p<0.001), function (p<0.001), anxiety symptoms (p<0.001) and catastrophizing (p<0.001) had improved. Depressive symptoms did not change (p=0.63). Between 6 months postoperative and the latest follow-up, none of the parameters changed further (p>0.05). Of the 65 patients analyzed, 21% had chronic pain of undefined origin at 6 months postoperative and 26% had chronic pain at the end of follow-up, with 50% also having neuropathic pain. Preoperatively, 40% of the 65 patients had neuropathic pain, 30% at 6 months (p=0.27) and 18% at 7.5 years after TKR (p=0.01).

CONCLUSION

The number of patients who have chronic pain after TKR is considerable, especially since knee pain stabilized at 6 months postoperative. Early detection is vital to prevent the pain from becoming chronic, which makes it more difficult to treat. Half the patients with persistent pain also had neuropathic pain, which should be detected before surgery so the patients can be referred to a specialized pain management center. The presence of anxiety and depressive symptoms and pain catastrophizing is not a contraindication to TKR, but these patients should be referred to specialists for treatment before surgery.

LEVEL OF EVIDENCE

IV, prospective cohort study.

Effect of medial opening wedge distal tibial tuberosity osteotomy on possible neuropathic pain in patients with osteoarthritis of the knee

BACKGROUND

There is a paucity of literature regarding the changes and features of neuropathic pain (NP) in knee osteoarthritis (OA) following medial opening wedge distal tibial tuberosity osteotomy (OWDTO). This study aimed to investigate the effect of OWDTO on NP in knee OA; we hypothesized that OWDTO improves knee symptoms and functions and also meets patient satisfaction in those with knee OA with possible NP or without NP.

METHODS

Fifty-two consecutive patients who underwent OWDTO were categorized into the unlikely NP and possible NP groups using the painDETECT questionnaire. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) score and the Knee Society Score 2011 (KSS 2011) were compared between the groups preoperatively and at the 1-year follow-up.

RESULTS

The number of patients having possible NP significantly decreased from 12 (23.1%) preoperatively to one (1.9%) postoperatively (p < 0.001). The patient with postoperative possible NP also had possible NP preoperatively. All preoperative sub-scores of WOMAC were significantly higher in the possible NP group than in the unlikely NP group (p = 0.018, 0.013, 0.004, and 0.005, respectively); however, the postoperative scores did not differ between the two groups. Regarding the KSS 2011, the preoperative scores for symptom and functional activities were significantly lower in the possible NP group than in the unlikely NP group (p = 0.031 and 0.024, respectively).

CONCLUSIONS

OWDTO is an effective surgery for patients with possible NP; it improves symptoms and knee function as well as meets patient satisfaction.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Wireless High-Frequency Peripheral Nerve Stimulation for Chronic Refractory Knee Pain Post-total Knee Replacement

The number of joint replacement surgeries, especially knee replacement surgeries, is rising with the rising geriatric population. Chronic unremitting knee pain post-total knee replacement surgery is a common phenomenon. Usually, the pain responds to conservative measures, including physical therapy and medical management. In some patients, the pain post-knee replacement surgery can be refractory and unremitting. In such scenarios, peripheral nerve stimulation, or neuromodulation, can be an effective option.

Preoperative Pain Catastrophizing and Neuropathic Pain Do Not Predict Length of Stay and Early Post-Operative Complications following Total Joint Arthroplasty

BACKGROUND

Both pain catastrophizing and neuropathic pain have been suggested as prospective risk factors for poor postoperative pain outcomes in total joint arthroplasty (TJA).

OBJECTIVE

We hypothesized that pain catastrophizers, as well as patients with pain characterized as neuropathic, would exhibit higher pain scores, higher early complication rates and longer lengths of stay following primary TJA.

METHODS

A prospective, observational study in a single academic institution included 100 patients with end-stage hip or knee osteoarthritis scheduled for TJA. In pre-surgery, measures of health status, socio-demographics, opioid use, neuropathic pain (PainDETECT), pain catastrophizing (PCS), pain at rest and pain during activity (WOMAC pain items) were collected. The primary outcome measure was the length of stay (LOS) and secondary measures were the discharge destinations, early postoperative complications, readmissions, visual analog scale (VAS) levels and distances walked during the hospital stay.

RESULTS

The prevalence of pain catastrophizing (PCS ≥ 30) and neuropathic pain (PainDETECT ≥ 19) was 45% and 20.4%, respectively. Preoperative PCS correlated positively with PainDETECT (rs = 0.501, p = 0.001). The WOMAC positively correlated more strongly with PCS (rs = 0.512 p = 0.01) than with PainDETECT (rs = 0.329 p = 0.038). Neither PCS nor PainDETECT correlated with the LOS. Using multivariate regression analysis, a history of chronic pain medication use was found to predict early postoperative complications (OR 38.1, p = 0.47, CI 1.047-1386.1). There were no differences in the remaining secondary outcomes.

CONCLUSIONS

Both PCS and PainDETECT were found to be poor predictors of postoperative pain, LOS and other immediate postoperative outcomes following TJA.

Presence of Night Pain, Neuropathic Pain, or Depressive Disorder Does Not Adversely Affect Outcomes After Total Knee Arthroplasty: A Prospective Cohort Study

BACKGROUND

A considerable proportion of patients warranting total knee arthroplasty (TKA) have night pain, neuropathic pain, and/or depressive disorder, which may not be resolved by TKA. This prospective, longitudinal cohort study aimed to document the prevalence of night pain, neuropathic pain, and depressive disorder in patients with advanced knee osteoarthritis undergoing TKA and to determine whether the specific coexisting pain and/or disorder at the time of TKA adversely affected postoperative outcomes.

METHODS

In this study, 148 patients undergoing TKA were longitudinally evaluated. The presence of night pain, neuropathic pain (determined using Douleur Neuropathique 4 [DN4]) and depressive disorder (determined using the Patient Health Questionnaire-9 [PHQ-9]) was determined before and 6 weeks, 3 months and 1 year after TKA. In addition, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and EuroQol-5 Dimension (EQ-5D) scores were assessed before and 1 year after TKA. Potential associations of night pain, neuropathic pain, and/or depressive disorder with pre- and postoperative WOMAC and EQ-5D scores were examined in subgroup analyses.

RESULTS

Preoperatively, 72% (n = 106) of patients reported night pain, and the prevalences of neuropathic pain and depressive disorder were 15% and 17%, respectively. Preoperatively, compared with patients without night pain, those with night pain had significantly poorer preoperative WOMAC scores, but no significant difference was seen between groups 1 year after TKA. Preoperatively, the WOMAC, EQ-5D, and EQ-5D health scores of patients with neuropathic pain were not significantly different from those of patients without neuropathic pain, and there was no difference in clinical outcome scores 1 year after TKA between these groups. Preoperatively, the patients with depressive disorder showed significantly poorer preoperative WOMAC, EQ-5D, and EQ-5D health scores than those without depressive disorder, but no significant differences in scores were observed 1 year after TKA between these groups.

CONCLUSION

This study revealed a considerable prevalence of night pain, neuropathic pain, and depressive disorder in patients undergoing TKA and that patients with these specific conditions reported poorer functional and quality of life scores preoperatively. However, such adverse effects disappeared after TKA. Our study findings suggest that TKA can provide satisfactory outcomes for patients with these specific conditions.

Different Prevalence of Neuropathic Pain and Risk Factors in Patients with Knee Osteoarthritis at Stages of Outpatient, Awaiting and after Total Knee Arthroplasty

Objective

Neuropathic pain (NP) plays an important role in patients with knee osteoarthritis (KOA). However, the prevalence of NP at different treatment stages including outpatient, awaiting and after total knee arthroplasty (TKA) have not been compared. The understanding of this issue and identify risk factors can help physicians develop individualized strategies to manage the pain of KOA. Therefore, the aim of the study is to investigate the prevalence and risk factors of NP at different treatment stages of KOA.

Methods

Patients diagnosed as KOA between August 2016 and August 2020 were enrolled in this cross‐sectional study and divided into three groups according to treatment stage, including outpatient stage, awaiting TKA stage (pre‐TKA) and after TKA stage (post‐TKA). A numeric rating scale (NRS) and PainDETECT questionnaire were used to evaluate nociceptive pain and NP. Patient demographics, radiological assessments using Kellgren–Lawrence (K‐L) grade, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were analyzed. Data analysis and statistics were processed using SPSS 20.0 and examined by ANOVA with/without Bonferroni correction or Kruskal–Wallis test. A chi‐square test was used to determine cross‐table data and calculate the odds ratio (OR) value.

Results

Of the 921 patients, the prevalence of possible and likely NP was 17.5% (56/320) and 2.5% (8/320) in the pre‐TKA group compared with 3.4% (8/233) and 0.4% (1/233) in the outpatient group and 1.4% (5/368) and 0.5% (2/368) in the post‐TKA group, respectively. In the pre‐TKA group, higher NRS (NRS >3; OR = 10.65, 95% CI: 3.25–34.92, P < 0.001) and WOMAC pain score (score > 10; OR = 4.88, 95% CI: 2.38–10.01, P < 0.001) conferred an increased risk of unclear pain. Age, gender, BMI and K‐L grade showed no significant differences among the unlikely, possible and likely NP groups.

Conclusion

Prevalence of NP is different at stages of out‐patient, awaiting and after TKA in patients with KOA. Patients awaiting TKA have the highest prevalence of NP compared with patients in outpatient and post‐TKA groups. In the patients waiting for TKA, higher NRS (NRS >3) and WOMAC pain scores (score > 10) are risk factors of NP.

High Prevalence of Pain Sensitization in Knee Osteoarthritis: A Meta-Analysis with Meta-Regression

OBJECTIVE

The aim of this meta-analysis was to study the evidence on pain sensitization in knee osteoarthritis (OA), providing a quantitative synthesis of its prevalence and impact. Factors associated with pain sensitization were also investigated.

METHODS

Meta-analysis; PubMed (MEDLINE), Cochrane Central Register (CENTRAL), and Web of Science were searched on February 2021. Level I to level IV studies evaluating the presence of pain sensitization in patients with symptomatic knee OA, documented through a validated method (questionnaires or quantitative sensory testing), were included. The primary outcome was the prevalence of pain sensitization. Factors influencing the prevalence were also evaluated, as well as differences in terms of pain thresholds between knee OA patients and healthy controls.

RESULTS

Fifty-three articles including 7,117 patients were included. The meta-analysis of proportion documented a prevalence of pain sensitization of 20% (95% confidence interval [CI] = 16%-26%) with a significant heterogeneity of results (I² = 89%, P < 0.001). The diagnostic tool used was the main factor influencing the documented prevalence of pain sensitization (P = 0.01). Knee OA patients presented higher pain sensitivity compared with healthy controls, both in terms of local pressure pain threshold (standardized mean difference [SMD] = -1.00, 95% CI = -1.67 to -0.32, P = 0.007) and distant pressure pain threshold (SMD = -0.54, 95% CI = -0.76 to -0.31, P < 0.001).

CONCLUSIONS

Knee OA pain presents features that are consistent with a significant degree of pain sensitization. There is a high heterogeneity in the reported results, mainly based on the diagnostic tool used. The identification of the best methods to detect pain sensitization is warranted to correctly evaluate and manage symptoms of patients affected by knee OA.

REGISTRATION

PROSPERO CRD42019123347.

Safety and Efficacy of Genicular Nerve Radiofrequency Ablation for Management of Painful Total Knee Replacement: A Systematic Review

Painful total knee replacement (TKR) without an obvious underlying identifiable pathology is not uncommon. Dissatisfaction after TKR can be up to 20%. Different treatment modalities, including non-operative and operative procedures, have been described in the literature. Radiofrequency ablation of genicular nerves (GNRFA) is emerging as a newer treatment modality for painful TKR without an obvious underlying identifiable pathology. Despite a modest number of publications demonstrating the usefulness of GNRFA in managing pain in knee osteoarthritis, the efficacy of GNRFA has not been completely established in the management of residual pain after TKR. This systematic review aimed to analyze all published studies (nine studies) on GNRFA as an option to manage residual pain after TKR. Based on this current systematic review, we noted that GNRFA is a modality to treat post residual pain and patients can anticipate improvement in pain up to three months with minimal complications. This article provides an overview of the currently available knowledge and techniques employed for this procedure, as well as the expected outcome and safety profile of GNRFA in painful TKR.

Clinical Course of Pain and Function Following Total Knee Arthroplasty: A Systematic Review and Meta-Regression

BACKGROUND

Total knee arthroplasty (TKA) is widely considered a successful intervention for osteoarthritis and other degenerative knee diseases. This study addresses the need for a high-quality meta-analysis that outlines the clinical course of pain and function post-TKA.

METHODS

The review included prospective cohort studies assessing pain or function of patients undergoing primary TKA at baseline (preoperatively) and at least 2 additional time points including one at least 12 months postoperatively. Two reviewers independently screened references, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. The time course of recovery of pain and function was modeled using fractional polynomial meta-regression.

RESULTS

In total, 191 studies with 59,667 patients were included, most with low risk of bias. The variance-weighted mean pain score (/100, 0 = no pain) was 64.0 (95% confidence interval [CI] 60.2-67.7) preoperatively, 24.1 (95% CI 20.3-27.9) at 3 months, 20.4 (95% CI 16.7-24.0) at 6 months, and 16.9 (95%CI 13.6-20.3) at 12 months, and remained low (10.1; 95% CI 4.8-15.4) at 10 years postoperatively. The variance-weighted mean function score (/100, 0 = worst function) was 47.1 (95% CI 45.7-48.4) preoperatively, 72.8 (95% CI 71.3-74.4) at 3 months, 76.3 (95% CI 74.7-77.8) at 6 months, and 78.1 (95%CI 76.4-79.7) at 12 months. Function scores were good (79.7; 95% CI 77.9-81.5) at 10 years postoperatively.

CONCLUSION

Patients undergoing primary TKA can expect a large and rapid but incomplete recovery of pain and function in the first postoperative year. At 10 years, the gains in pain scores may still remain while there is an improvement in function.

Capsaicin 179-mg cutaneous patch in the treatment of post-surgical neuropathic pain: a scoping review of current evidence and place in therapy

INTRODUCTION

The use of topical agents has been suggested for post-surgical neuropathic pain. A high-concentration capsaicin 179-mg cutaneous patch (Qutenza™) is licensed in adults for chronic neuropathic pain in the EU, and neuropathic pain with post-herpetic neuralgia and neuropathic pain with diabetic peripheral neuropathy in the USA. This article aims to describe the use of a topical capsaicin 179-mg cutaneous patch in the treatment of PSNP.

AREA COVERED

This narrative review presents the relevant clinical aspects of the use of a topical capsaicin 179-mg cutaneous patch for the treatment of post-surgical neuropathic pain (PSNP). Randomized control trials, observational studies, case series, and reports investigating the clinical use of the capsaicin patch were searched through MEDLINE, EMBASE, AMED, Cochrane Library, CINAHL, Web of Science, and ROAD databases. Trials from citation lists of reviewed articles and hand-searching were added. The search concluded in September 2020. 10/20 articles were considered.

EXPERT OPINION

Some clinical studies demonstrated the efficacy of the capsaicin 179-mg patch in PSNP as monotherapy and concomitant treatment with oral treatments. This topical treatment of PSNP is better tolerated and accepted compared with systemic treatments. To maximize the effectiveness of the treatment, correct administration recommendations should be followed.

Systematic review and meta-analysis of the prevalence of neuropathic-like pain and/or pain sensitization in people with knee and hip osteoarthritis

OBJECTIVE

To determine the prevalence of neuropathic-like pain (NP) and pain sensitization (PS) defined by self-report questionnaires in knee and hip osteoarthritis, and whether prevalence is potentially explained by disease-severity or affected joint.

DESIGN

MEDLINE, EMBASE, CINAHL were systematically searched (1990-April 2020) for studies describing the prevalence of NP and PS in knee and hip osteoarthritis using self-report questionnaires. Random-effects meta-analysis was performed. Statistical heterogeneity between studies and sub-groups (affected joint and population source as a proxy for disease severity) was assessed (I² statistic and the Chi-squared test).

RESULTS

From 2,706 non-duplicated references, 39 studies were included (2011-2020). Thirty-six studies reported on knee pain and six on hip pain. For knee osteoarthritis, the pooled prevalence of NP was: using PainDETECT, possible NP(score ≥13) 40% (95%CI 32-48%); probable NP(score >18) 20% (95%CI 15-24%); using Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, 32% (95%CI 26-38%); using Douleur Neuropathique (DN4) 41% (95% CI 24-59%). The prevalence of PS using Central Sensitization Inventory (CSI) was 36% (95% CI 12-59%). For hip osteoarthritis, the pooled prevalence of NP was: using PainDETECT, possible NP 29% (95%CI 22-37%%); probable NP 9% (95%CI 6-13%); using DN4 22% (95%CI 12-31%) in one study. The prevalence of possible NP pain was higher at the knee (40%) than the hip (29%) (difference 11% (95% CI 0-22%), P = 0.05).

CONCLUSIONS

Using self-report questionnaire tools, NP was more prevalent in knee than hip osteoarthritis. The prevalence of NP in knee and hip osteoarthritis were similar for each joint regardless of study population source or tool used. Whether defining NP using self-report questionnaires enables more effective targeted therapy in osteoarthritis requires investigation.

Return to Play and Performance in Golfers After Total Knee Arthroplasty: Does Component Type Matter?

BACKGROUND

Golf is a popular sport among patients undergoing total knee arthroplasty (TKA). The golf swing requires significant knee rotation, which may lead to changes in golfing ability postoperatively. The type of implant used may alter the swing mechanics or place different stresses on the knee. The purpose of this study was to evaluate golf performance and subjective stability after TKA and compare outcomes between cruciate-retaining (CR) and posterior-stabilized (PS) implants.

HYPOTHESIS

Patients with CR implants will experience better stability during the golf swing compared to patients with PS implants.

STUDY DESIGN

Retrospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Patients who underwent primary TKA were identified from the medical record and sent an electronic questionnaire focusing on return to play (RTP), performance, pain, and stability during the golf swing. Knee injury and Osteoarthritis Outcome Scores (KOOS) were collected before and at multiple time points after surgery. Patients were surveyed postoperatively and asked to evaluate overall performance, pain, and stability before and after surgery. Outcomes were compared based on implant type.

RESULTS

Most patients (81.5%) were able to return to golf at an average of 5.3 ± 3.1 months from surgery. The average postoperative KOOS was 74.6 ± 12.5 in patients able to RTP compared with 64.4 ± 9.5 in those who were not (P < 0.05). Knee pain during golf significantly improved from 6.4 ± 2.1 to 1.8 ± 2.2 (P < 0.01). There were no significant differences in pain, performance, or stability between the CR and PS patients.

CONCLUSION

Most patients can successfully return to golfing after TKA. Knee replacement offers patients reliable pain relief during the golf swing and fewer physical limitations during golf, with no detriment to performance. There is no difference in performance or subjective knee stability based on component type.

CLINICAL RELEVANCE

Understanding associated outcomes of different TKA knee systems allows for unbiased and confident recommendations of either component to golfers receiving total knee replacement.

Total Knee Arthroplasty Postsurgical Chronic Pain, Neuropathic Pain, and the Prevalence of Neuropathic Symptoms: A Prospective Observational Study in Turkey

Purpose

Chronic post-surgical pain (CPSP) is a detrimental condition that persists at least two months after surgical procedures and seriously affects patients' quality of life. Although its incidence varies according to operation types and definitions, its prevalence is between 3% and 85%. The purpose of this study is to evaluate the prevalence of CPSP and neuropathic pain in patients undergoing TKA for osteoarthritis.

Patients and Methods

In this study, patients who had undergone total knee arthroplasty (TKA) were examined prospectively and observationally. 42 patients were included in the study. Numeric rate scale (NRS) for developing chronic pain, Douleur Neuropathique 4 (DN-4) questionnaire to evaluate neuropathic pain and symptoms, and von Frey filaments to evaluate mechanical hyperesthesia and alladony.

Results

NRS scores were 1 or higher for all patients. Twenty-seven patients constituted the mild pain group (NRS: 1-4), and 15 patients constituted the moderate pain group (NRS: 4-7). The number of patients defined as having "neuropathic pain," according to DN-4 scores, was 17 (40.4%; DN-4 ≥ 4). The moderate pain group reported greater severity of neuropathic symptoms on average than the mild pain group (p = 0.039). When patients knees affected by TKA were divided into suprapatellar, patellar, and infrapatellar regions and evaluated with von Frey filaments, a significant difference was found between the three regions (p < 0.05).

Conclusion

In this study, we showed-unlike other studies-that the rate of neuropathic pain was higher among CPSP patients, and all patients had neuropathic symptoms. In evaluating patients knees with von Frey filaments, we showed that the neuropathic component of patients' pain occurred mostly in the knee's infrapatellar region. Although the incidence of CPSP and neuropathic pain in these patients was higher than expected, we think CPSP, its diagnosis, and its treatment present an important issue that requires further examination.

Prospective randomized trial of continuous femoral nerve block with posterior capsular injection versus periarticular injection for analgesia in primary total knee arthroplasty

Background:

Femoral nerve block (NB) and periarticular injection (PI) are 2 common options for pain control after total knee arthroplasty (TKA). We performed a prospective triple-blinded randomized trial comparing continuous femoral NB to PI, with follow-up to 1 year.

Methods:

Patients younger than 70 years of age who were scheduled to undergo elective primary TKA under spinal anesthesia between 2009 and 2010 were randomly allocated to receive either continuous femoral NB or PI. Patients in the NB group received ropivacaine through an NB catheter and a sham saline PI. The PI group received a PI of ropivacaine, morphine, ketorolac and epinephrine, and a sham saline infusion via an NB catheter. Both groups had standardized oral analgesia preoperatively, spinal anesthesia and sedation, and postoperative analgesia. Surgeons, anesthesiologists, patients and assessors were blinded to group assignment. Pain was measured twice daily on postoperative days 1 and 2, at rest and with motion, with a numeric rating scale. Patient satisfaction, pain (Oxford Knee Score) and range of motion were assessed at 1 year.

Results:

There were 39 participants in the NB group and 35 participants in the PI group. There were no statistically significant differences between the groups at baseline. Statistically but nonclinically significant reductions in pain scores on postoperative day 2 and in narcotic need on the day of surgery were found in the PI group. Patient-reported satisfaction did not differ at any time point. At 1 year, knee flexion was significantly greater in the NB group than in the PI group (mean range of motion 120° v. 110°, p = 0.03).

Conclusion:

There was no demonstrated improvement in pain control with the use of an NB versus PI when used with multimodal analgesia. Clinicians should opt for the modality that has the best efficiency for their surgical environment. ClinicalTrials.gov # NCT00869037

Effectiveness of Perineural Injections Combined with Standard Postoperative Total Knee Arthroplasty Protocols in the Management of Chronic Postsurgical Pain After Total Knee Arthroplasty

Background

Despite increased experience and technical developments in total knee arthroplasty (TKA), chronic postsurgical pain (CPSP) remains one of physicians’ biggest challenges. The aim of the present study was to evaluate the effectiveness of perineural injection therapy (PIT) in the management of CPSP after TKA.

Material/Methods

A total of 60 patients who had been surgically treated with TKA because of advanced knee osteoarthritis was included in the present study. The study included 2 groups. Group A consisted of patients who received 3 rounds of PIT combined with standard postoperative TKA protocol during the same period. Group B received standard postoperative TKA protocols (rehabilitation programs, oral and intravenous analgesics). Clinical effectiveness was evaluated via Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analog Scale (VAS) at baseline and 1-, 3-, and 6-month follow-ups.

Results

All repeated measures showed significant improvements (P<0.001) in both groups for VAS and WOMAC scores. These scores were significantly better in group A in all follow-up periods compared with group B (P<0.001). Twenty-nine patients (93.5%) in group A reported excellent or good outcomes compared with 26 patients (89.6%) in group B.

Conclusions

PIT is a promising approach in CPSP with minimal cost, simple and secure injection procedures, minimal side effects, and higher clinical efficacy.

Does preoperative neuropathic-like pain and central sensitisation affect the post-operative outcome of knee joint replacement for osteoarthritis? A systematic review and meta analysis

BACKGROUND

Almost a third of those undergoing knee replacement for osteoarthritis have poor outcomes despite technically successful surgery. Preoperative neuropathic-like pain and/or pain sensitisation may increase the risk of pain following joint replacement.

OBJECTIVE

To examine whether preoperative neuropathic-like pain and pain sensitisation predicts pain, function and satisfaction following joint replacement for knee osteoarthritis.

DESIGN

Systematic review with meta-analysis.

METHODS

Medline, EMBASE and CINAHL were systematically searched until March 2020. Studies detecting neuropathic-like pain and/or sensitisation using self-report questionnaires prior to knee replacement for osteoarthritis, and relating this to post-operative outcomes were identified. Data extraction, risk of bias assessment and meta-analysis were performed, where appropriate.

RESULTS

Five manuscripts, including one preprint, examining six cohorts were included: four used painDETECT or modified painDETECT, one the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, and another the Central Sensitisation Inventory to identify preoperative characteristics. Three studies showed preoperative neuropathic-like pain or sensitisation was associated with more intense post-operative pain. All four studies examining the risk of significant pain after knee replacement suggested it was increased after >3 months. The only study examining patient satisfaction and function found reduced satisfaction, but no difference in function in those with preoperative sensitisation. Meta-analysis found the relative risk of increased pain following knee replacement in those with neuropathic-like pain (painDETECT ≥13) to be 2.05 (95% confidence intervals 1.51, 2.79).

CONCLUSION

These results provide consistent but limited evidence that self-report tools detecting neuropathic-like pain and/or pain sensitisation, predict patients at higher risk of pain following knee replacement.

Chronic neuropathic pain after traumatic peripheral nerve injuries in the upper extremity: prevalence, demographic and surgical determinants, impact on health and on pain medication

Background and aims Aside from the long term side effects of a nerve injury in the upper extremity with devastating consequences there is often the problem of chronic neuropathic pain. The studies concerning the prevalence of persistent pain of neuropathic origin after peripheral nerve injuries are sparse. The prevalence and risk factors associated with chronic neuropathic pain after nerve injuries in the upper extremity were assessed. Methods A standardized data collection template was employed prospectively and retrospectively for all patients with traumatic nerve injuries accepted at the Hand Surgery Department, Uppsala, Sweden between 2010 and 2018. The template included demographic data, pain diagnosis, type of injured nerve, level of injury, date of the lesion and repair, type of procedure, reoperation, time since the procedure, S-LANSS questionnaire (Self report-Leeds Assessment of Neuropathic Symptoms and Signs), RAND-36 (Item short form health survey), QuickDASH (Disability of Shoulder, Arm and Hand) and additional questionnaires concerned medication, pain intensity were sent to 1,051 patients with nerve injuries. Partial proportional odds models were used to investigate the association between persistent pain and potential predictors. Results More than half of the patients undergoing a surgical procedure developed persistent pain. Prevalence of neuropathic pain was 73% of the patients with pain (S-LANSS ≥ 12 or more). Multivariate analysis indicated that injury of a major nerve OR 1.6 (p = 0.013), years from surgery OR 0.91 (p = 0.01), younger age OR 0.7 (p < 0.001), were the main factors for predicting pain after surgery. The type of the nerve injured was the strongest predictor for chronic pain with major nerves associated with more pain (p = 0.019). Conclusions A high prevalence of chronic pain and neuropathic pain with a negative impact on quality of life and disability were found in patients after traumatic nerve injury. Major nerve injury, younger age and less time from surgery were predictors for chronic pain.

How Does Preoperative Central Sensitization Affect Quality of Life Following Total Knee Arthroplasty?

BACKGROUND

Central sensitization (CS) has been recently identified as a significant risk factor for persistent pain and patient dissatisfaction following total knee arthroplasty (TKA). However, it remains unclear as to whether the preoperative CS persists after the elimination of a nociceptive pain source by TKA, or how CS affects the quality of life after TKA.

METHODS

A total of 222 consecutive patients undergoing primary TKA were enrolled in the study. All patients were preoperatively screened for CS using the Central Sensitization Inventory (CSI) and categorized into either a CS (n = 55; CSI ≥ 40) or non-CS group (n = 167; CSI < 40). CSI, pain visual analog scale (VAS), Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index score, and satisfaction were recorded at postoperative 2 years.

RESULTS

Two years after TKA, preoperative CS remained unchanged; there was no difference between preoperative and postoperative CSI scores, and both preoperative and postoperative CSI severity levels were similar (P > .1). The CS group showed worse pain VAS, KSS, and Western Ontario and McMaster Universities Osteoarthritis Index scores than did the non-CS group (P < .01) and more patients in the CS group were dissatisfied with all activities (P < .01). However, a similar percentage of the CS group achieved the previously documented minimal clinically important difference in pain VAS and KSS, compared with the non-CS group. Multivariate regression analysis revealed that preoperative CSI scores were associated with dissatisfaction at postoperative 2 years.

CONCLUSION

Preoperative CS was persistent at 2 years after TKA. Although CS patients achieved comparable clinical improvement following TKA, CS patients had worse quality of life, functional disability, and dissatisfaction than non-CS patients.

A sleep disturbance after total knee arthroplasty

Background:

Knee osteoarthritis (OA) is common arthritis in elderly. Total knee arthroplasty; (TKA) is effective to restore mobility and improve quality of life in patients with OA. One of TKA complications is sleep disturbance.

Objective:

Aim was to evaluate sleep disturbance after TKA despite differences in postoperative pain managements.

Methods:

Prospective cohort study was performed on 67 patients who underwent primary TKA by different surgeons during May to March 2019. Samples were collected randomly from different hospitals in Sulaimani, Kurdistan, Iraq. Sleep pattern was assessed by Pittsburgh Sleep Quality Index (PSQI) and pain was assessed by visual analogue scale (VAS) for three months postoperatively.

Results:

Mean ± standard deviation (SD) age (year) and body mass index (BMI; kg/m²) of participants were 64.2 ± 7.5 (range: 40–82) and 27.3 ± 3.7 (range: 21.3–41.6), respectively. About 83.6% were females with male to female ratio of (0.2:1). There were statistically insignificant associations of age, gender, BMI, and history of diabetes mellitus with PSQI. Degree of pain was gradually decreasing during follow-up, but sleep was better at beginning followed by peaked disturbance after one month, then it started to improve gradually at end of follow-up.

Conclusions:

Sleep disturbance assessment needs multimodal approaches in order to improve it and satisfy patients.

Chronic, Active Inflammation in Patients With Failed Total Knee Replacements Undergoing Revision Surgery

Chronic pain and restricted knee motion is a significant problem following the total knee arthroplasty (TKA). The molecular pathogenesis of pain post-TKA is not known and no targeted therapeutic intervention is available. The aim of this study was to investigate whether pro-inflammatory mediators are elevated in revision knee patients, indicating an active, ongoing inflammatory process that may contribute to pain. Twelve key markers (pro-inflammatory cytokines granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin 5 [IL-5], IL-8 and IL-10, chemokines CCL2, CCL3, CCL4, and CCL13, mediators of angiogenesis Flt-1, vascular endothelial growth factor, and cell migration vascular cell adhesion molecule 1 and intercellular adhesion molecule 1) were measured in knee tissue and synovial fluid (SF) from primary TKA (n = 29) and revision patients (n = 32). Indications for surgery were osteoarthritis (OA) for primary TKA, and component loosening (n = 11), stiffness (n = 11), laxity pattern (n = 8), or progression of OA in patella resurfacing (n = 3) for revision surgery. Pain levels (WOMAC score) were higher in revision than primary patients (p ≤ 0.05). Time from primary to revision ranged from 8 months to 30 years (median 10 years). All markers were elevated in revision TKA; there was no trend toward decreasing levels with greater time from primary surgery for any marker studied in SF. Similar results were seen in knee tissue. We found no differences comparing indications for revision surgery (p ≥ 0.05). The elevation of inflammatory mediators in painful post-TKA knees requiring revision suggests active, chronic inflammation. Characterization of upregulated markers provides rationale for targeted therapy, even many years from the primary surgery. © 2019 The Authors. Journal of Orthopaedic Research^® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 37:2316-2324, 2019.

Why do patients not kneel after total knee replacement? Is neuropathic pain a contributing factor?

AIMS

Despite kneeling being an important and valued function of the knee, a proportion of patients are unable to kneel following arthroplasty. We explore the reasons for this, and assess whether neuropathic pain is a contributing factor.

METHODS

In this observational study, data was collected prospectively for 134 knees. At one year follow-up, patients completed a semi-structured questionnaire, the Oxford Knee Score (OKS), and the painDETECT score. Ability to kneel was assessed by question 7 of the OKS. Change in kneeling ability was assessed using Wilcoxon signed-rank test, normal data with independent t-test, and a regression and ANOVA analysis performed to assess predictors of kneeling ability.

RESULTS

88% of patients had tried kneeling post-operatively. There was no change in kneeling ability for the whole cohort from pre- to post-operatively (p = 0.313). Patient reasons for not kneeling varied. Male gender, younger age and a reduced pain score were all significantly associated with a greater ability to kneel postoperatively. There was a trend towards an improved ability with increased flexion. Mean pain scores for all kneeling abilities lay within the nociceptive rather than neuropathic range.

CONCLUSION

Kneeling ability varies greatly post-knee replacement, and is multifactorial. Greater pain is a contributing factor to the inability to kneel postoperatively, but this appears to be nociceptive rather than neuropathic in nature.

Neuropathic Pain after Shoulder Arthroplasty: Prevalence, Impact on Physical and Mental Function, and Demographic Determinants

Purpose: The objectives of this survey study were to provide an estimate of the prevalence of neuropathic pain (NP) and to explore the cross-sectional and longitudinal group differences postoperatively. Method: A cohort of consecutive patients who had undergone total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), or humeral head replacement (HHR) were surveyed within an average of 3.8 years after surgery. Questionnaires completed at the time of the survey were the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale, the visual analogue scale (VAS) for pain, the Western Ontario Osteoarthritis of the Shoulder (WOOS) index, the Patient Health Questionnaire-9 (PHQ-9), and a satisfaction questionnaire. Results: Of the 141 candidates who were invited to participate in the study, 115 patients participated (85 TSA, 21 HHR, and 9 RSA), for an 82% response rate. Five patients (4%) met the criteria for NP, of whom one had a loosening of the prosthesis and required further surgery. Having NP was associated with greater pain (VAS; p=0.001), greater depression (PHQ-9; p=0.001), more disability (WOOS; p=0.030), and less satisfaction with the surgery (p=0.014). There was no relationship between the presence of NP and patients' age, sex, preoperative pain, range of motion results, or WOOS scores (p>0.05). Conclusions: Persistent pain of neuropathic origin is not common after shoulder arthroplasty, but it is a significant contributor to poor mental and physical well-being and thus warrants further research.

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

Selective peripheral nerve resection for treatment of persistent pain around the knee joint after total knee arthroplasty

Objective This study was performed to determine the efficacy of selective peripheral nerve resection for treatment of persistent neuropathic pain after total knee arthroplasty (TKA). Methods Patients who underwent TKA in our department from January 2013 to July 2016 and experienced persistent pain around the knee joint after TKA were retrospectively included in the current study. Sixty patients were divided into experimental and control groups according the treatment they received. The treatment effect was evaluated by the Hospital for Special Surgery (HSS) knee score and visual analog scale (VAS) pain score preoperatively and at 1, 2, 3, 6, and 12 months postoperatively. Results The HSS knee scores were higher in both groups after than before the treatment, and HSS knee scores were significantly higher in the experimental group than in the control group. The VAS pain scores were lower in both groups after than before the treatment, and VAS pain scores were significantly lower in the experimental group than in the control group. Conclusions Selective peripheral nerve resection is an effective treatment method for persistent neuropathic pain after TKA.

The ACTTION-APS-AAPM Pain Taxonomy (AAAPT) Multidimensional Approach to Classifying Acute Pain Conditions

Objective

With the increasing societal awareness of the prevalence and impact of acute pain, there is a need to develop an acute pain classification system that both reflects contemporary mechanistic insights and helps guide future research and treatment. Existing classifications of acute pain conditions are limiting, with a predominant focus on the sensory experience (e.g., pain intensity) and pharmacologic consumption. Consequently, there is a need to more broadly characterize and classify the multidimensional experience of acute pain.

Setting

Consensus report following expert panel involving the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION), American Pain Society (APS), and American Academy of Pain Medicine (AAPM).

Methods

As a complement to a taxonomy recently developed for chronic pain, the ACTTION public-private partnership with the US Food and Drug Administration, the APS, and the AAPM convened a consensus meeting of experts to develop an acute pain taxonomy using prevailing evidence. Key issues pertaining to the distinct nature of acute pain are presented followed by the agreed-upon taxonomy. The ACTTION-APS-AAPM Acute Pain Taxonomy will include the following dimensions: 1) core criteria, 2) common features, 3) modulating factors, 4) impact/functional consequences, and 5) putative pathophysiologic pain mechanisms. Future efforts will consist of working groups utilizing this taxonomy to develop diagnostic criteria for a comprehensive set of acute pain conditions.

Perspective

The ACTTION-APS-AAPM Acute Pain Taxonomy (AAAPT) is a multidimensional acute pain classification system designed to classify acute pain along the following dimensions: 1) core criteria, 2) common features, 3) modulating factors, 4) impact/functional consequences, and 5) putative pathophysiologic pain mechanisms.

Conclusions

Significant numbers of patients still suffer from significant acute pain, despite the advent of modern multimodal analgesic strategies. Mismanaged acute pain has a broad societal impact as significant numbers of patients may progress to suffer from chronic pain. An acute pain taxonomy provides a much-needed standardization of clinical diagnostic criteria, which benefits clinical care, research, education, and public policy. For the purposes of the present taxonomy, acute pain is considered to last up to seven days, with prolongation to 30 days being common. The current understanding of acute pain mechanisms poorly differentiates between acute and chronic pain and is often insufficient to distinguish among many types of acute pain conditions. Given the usefulness of the AAPT multidimensional framework, the AAAPT undertook a similar approach to organizing various acute pain conditions.

The ACTTION-APS-AAPM Pain Taxonomy (AAAPT) Multidimensional Approach to Classifying Acute Pain Conditions

OBJECTIVE

With the increasing societal awareness of the prevalence and impact of acute pain, there is a need to develop an acute pain classification system that both reflects contemporary mechanistic insights and helps guide future research and treatment. Existing classifications of acute pain conditions are limiting, with a predominant focus on the sensory experience (eg, pain intensity) and pharmacologic consumption. Consequently, there is a need to more broadly characterize and classify the multidimensional experience of acute pain.

SETTING

Consensus report following expert panel involving the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION), American Pain Society (APS), and American Academy of Pain Medicine (AAPM).

METHODS

As a complement to a taxonomy recently developed for chronic pain, the ACTTION public-private partnership with the US Food and Drug Administration, the APS, and the AAPM convened a consensus meeting of experts to develop an acute pain taxonomy using prevailing evidence. Key issues pertaining to the distinct nature of acute pain are presented followed by the agreed-upon taxonomy. The ACTTION-APS-AAPM Acute Pain Taxonomy will include the following dimensions: 1) core criteria, 2) common features, 3) modulating factors, 4) impact/functional consequences, and 5) putative pathophysiologic pain mechanisms. Future efforts will consist of working groups utilizing this taxonomy to develop diagnostic criteria for a comprehensive set of acute pain conditions.

PERSPECTIVE

The ACTTION-APS-AAPM Acute Pain Taxonomy (AAAPT) is a multidimensional acute pain classification system designed to classify acute pain along the following dimensions: 1) core criteria, 2) common features, 3) modulating factors, 4) impact/functional consequences, and 5) putative pathophysiologic pain mechanisms.

CONCLUSIONS

Significant numbers of patients still suffer from significant acute pain, despite the advent of modern multimodal analgesic strategies. Mismanaged acute pain has a broad societal impact as significant numbers of patients may progress to suffer from chronic pain. An acute pain taxonomy provides a much-needed standardization of clinical diagnostic criteria, which benefits clinical care, research, education, and public policy. For the purposes of the present taxonomy, acute pain is considered to last up to seven days, with prolongation to 30 days being common. The current understanding of acute pain mechanisms poorly differentiates between acute and chronic pain and is often insufficient to distinguish among many types of acute pain conditions. Given the usefulness of the AAPT multidimensional framework, the AAAPT undertook a similar approach to organizing various acute pain conditions.

[A review on psychosomatic factors affecting the outcome after total knee-arthroplasty (TKA)]

A review on psychosomatic factors affecting the outcome after total knee-arthroplasty (TKA) Objectives: In today's ageing Western societies, arthroplasty is a common treatment for endstage osteoarthritis. Despite highly developed implants and surgery, however, this treatment does not always succeed in relieving pain and restoring joint function, i.e., in restoring satisfactory algofunction. Clinicians partly blame psychological factors for this discrepancy, especially in the absence of objective medical complications.

METHODS

The present review summarizes previous studies on the role of psychosomatic interactions affecting the course after total knee arthroplasty (TKA).

RESULTS

During the perioperative period, patients with TKA suffer from marked psychic distress that is also linked to the postoperative algofunction.

CONCLUSIONS

We discuss the theoretical and clinical implications of the findings reviewed.

Post-operative patient-related risk factors for chronic pain after total knee replacement: a systematic review

OBJECTIVE

To identify postoperative patient-related risk factors for chronic pain after total knee replacement (TKR).

DESIGN

The systematic review protocol was registered on the International Prospective Register of Systematic Reviews (CRD42016041374). MEDLINE, Embase and PsycINFO were searched from inception to October 2016 with no language restrictions. Key articles were also tracked in the Institute for Scientific Information (ISI) Web of Science. Cohort studies evaluating the association between patient-related factors in the first 3 months postoperatively and pain at 6 months or longer after primary TKR surgery were included. Screening, data extraction and assessment of methodological quality were undertaken by two reviewers. The primary outcome was pain severity in the replaced knee measured with a patient-reported outcome measure at 6 months or longer after TKR. Secondary outcomes included adverse events and other aspects of pain recommended by the core outcome set for chronic pain after TKR.

RESULTS

After removal of duplicates, 16 430 articles were screened, of which 805 were considered potentially relevant. After detailed evaluation of full-text articles, 14 studies with data from 1168 participants were included. Postoperative patient-related factors included acute pain (eight studies), function (five studies) and psychosocial factors (four studies). The included studies had diverse methods for assessment of potential risk factors and outcomes, and therefore narrative synthesis was conducted. For all postoperative factors, there was insufficient evidence to draw firm conclusions about the association with chronic pain after TKR. Selection bias was a potential risk for all studies, as none were reported to be conducted at multiple centres.

CONCLUSION

This systematic review found insufficient evidence to draw firm conclusions about the association between any postoperative patient-related factors and chronic pain after TKR. Further high-quality research is required to provide a robust evidence base on postoperative risk factors, and inform the development and evaluation of targeted interventions to optimise patients' outcomes after TKR.

Neuropathic pain-like symptoms and pre-surgery radiographic severity contribute to patient satisfaction 4.8 years post-total joint replacement

AIM

To investigate a comprehensive range of factors that contribute to long-term patient satisfaction post-total joint replacement (TJR) in people who had undergone knee or hip replacement for osteoarthritis.

METHODS

Participants (n = 1151) were recruited from Nottinghamshire post-total hip or knee replacement. Questionnaire assessment included medication use, the pain-DETECT questionnaire (PDQ) to assess neuropathic pain-like symptoms (NP) and TJR satisfaction measured on average 4.8 years post-TJR. Individual factors were tested for an association with post-TJR satisfaction, before incorporating all factors into a full model. Data reduction was carried out using LASSO and receiver operator characteristic (ROC) curve analysis was used to quantify the contribution of variables to post-TJR satisfaction.

RESULTS

After data reduction, the best fitting model for post-TJR satisfaction included various measures of pain, history of revision surgery, smoking, pre-surgical X-ray severity, WOMAC function scores and various comorbidities. ROC analysis of this model gave AUC = 0.83 (95%CI: 0.80-0.85). PDQ scores were found to capture much of the variation in post-TJR satisfaction outcomes: AUC = 0.79 (0.75-0.82). Pre-surgical radiographic severity was associated with higher post-TJR satisfaction: OR_satisfied = 2.06 (95%CI: 1.15-3.69), P = 0.015.

CONCLUSION

These results highlight the importance of pre-surgical radiographic severity, post-TJR function, analgesic medication use and NP in terms of post-TJR satisfaction. The PDQ appears to be a useful tool in capturing factors that contribute to post-TJR satisfaction.

Perioperative Pain Management Strategies for Amputation: A Topical Review

Objective

To review acute pain management strategies in patients undergoing amputation with consideration of preoperative patient factors, pharmacologic/interventional modalities, and multidisciplinary care models to alleviate suffering in the immediate post-amputation setting.

Background

Regardless of surgical indication, patients undergoing amputation suffer from significant residual limb pain and phantom limb pain in the acute postoperative phase. Most studies have primarily focused on strategies to prevent persistent pain with inclusion of immediate postoperative outcomes as secondary measures. Pharmacologic agents, including gabapentin, ketamine, and calcitonin, and interventional modalities such as neuraxial and perineural catheters, have been examined in the perioperative period.

Design

Focused Literature Review.

Results

Pharmacologic agents (gabapentin, ketamine, calcitonin) have not shown consistent efficacy. Neuraxial analgesia has demonstrated both an opioid sparing and analgesic benefit while results have been mixed regarding perineural catheters in the immediate post-amputation setting. However, several early studies of perineural catheters employed sub-optimal techniques (distal surgical placement), and prolonged use of perineural catheters may provide a sustained benefit. Regardless of analgesic technique, a multidisciplinary approach is necessary for optimal care.

Conclusion

Patient-tailored analgesic regimens utilizing catheter-based techniques are essential in the acute post-amputation phase and should be implemented in all patients undergoing amputation. Future research should focus on improved measurement of acute pain and comparisons of effective analgesic regimens instead of single techniques.

The characterisation of unexplained pain after knee replacement

Background

The aims of this study were to characterise the pain experienced by patients with chronic pain after knee replacement (KR), in whom no apparent 'orthopaedic' problem could be identified, and to establish how many have pain sensitisation problems (including neuropathic pain).

Methods

A total of 44 patients were prospectively evaluated at a multidisciplinary tertiary referral clinic by an orthopaedic surgeon, pain specialist, rheumatologist and physiotherapist. These patients had been pre-screened by an orthopaedic surgeon to remove cases where there was an obvious cause of pain that could be treated with revision surgery. They were then followed up to find out whether any subsequent interventions had occurred.

Results

The mean time since surgery was 29 months (range: 3-108 months), and 18% were revision KR. Patients were evaluated for symptoms of nociceptive pain, allodynia, pains elsewhere and psychosocial factors. The patients were categorised into nociceptive pain 43% (n = 19), pain sensitisation 25% (n = 11) and mixed pain 32% (n = 14). Mean Visual Analogue Score (VAS) pain scores were 6.7/10 with high scores for both constant (66%) and intermittent (70%) pain elements, and pain caused high levels of interference with life. Fifty percent suffered depression and 25% suffered widespread pains (more than three pains elsewhere in the body). Patients with widespread pains suffered more pain (p = 0.01) and higher rates of both pain sensitisation (p = 0.07) and thermal allodynia (p < 0.04).

Conclusion

Patients after KR can experience severe pain that interferes with their lives, depression and many have pain sensitisation problems rather than any local, nociceptive cause. We advocate screening patients with unexplained pain after KR for pain sensitisation problems, pains at other sites and depression. Appropriate further treatment and multidisciplinary interventions can then be arranged.

High correlation of the Oxford Knee Score with postoperative pain, but not with performance-based functioning

PURPOSE

The Oxford Knee Score (OKS) is a widely known patient-related outcome measure (PROM) to determine pain and knee functioning before and after total knee arthroplasty (TKA). Self-reported function is mainly influenced by change in pain; therefore, it was hypothesized that the OKS correlates more with pain than with performance-based functioning.

METHODS

In a prospective cohort of 88 patients, who had a cementless mobile-bearing TKA, included in a randomized clinical trial, the correlation between the overall OKS, and its subscales for pain (PCS) and function (FCS), with performance-based functioning using the DynaPort^® Knee Score (DKS), visual analogue scale score for pain (VAS) and the Knee Society Score (KSS) was evaluated. All scores were measured preoperatively, 6 months and 1 year after surgery. Overall change in outcome over time was analysed until 5 years after surgery.

RESULTS

All scores improved over time. The DKS was influenced by sex, preoperative BMI and age. The internal consistency of the OKS PCS increased over time, whereas the OKS FCS remained the same. The mean postoperative OKS FCS showed moderate correlation with the DKS (r = 0.65, p < 0.001), and the mean postoperative OKS and OKS PCS showed high correlation with the VAS (r = -0.79 and r = -0.82, respectively, p < 0.001). The mean postoperative KSS showed high correlations with the OKS (r = 0.80, p < 0.001), the OKS PCS (r = 0.72 p < 0.001) and OKS FCS (r = 0.74, p < 0.001).

CONCLUSION

The postoperative OKS and the OKS PCS showed high correlation with pain, but only the postoperative OKS FCS was well correlated with performance-based functioning. This suggests that the OKS is more related to pain and tells us less on postoperative functioning. This is important when the OKS as PROM is used to evaluate the quality of orthopaedic care of patients with TKA.

LEVEL OF EVIDENCE

III.

Association between Neuropathic Pain and Reported Disability after Total Knee Arthroplasty

PURPOSE

To determine whether reporting neuropathic pain (NP) at an average of 5 years after total knee arthroplasty (TKA) was related to patient age, sex, preoperative comorbidity, arthritis self-efficacy, or disability before surgery and at 1 year after surgery. The estimate of NP prevalence and cross-sectional group differences were explored at 5 years after surgery.

METHODS

A subsample of participants in a formal research study was contacted via mail approximately 5 years after undergoing surgery and were sent four questionnaires: the Western Ontario and McMaster Universities Osteoarthritis Index, the Patient Health Questionnaire, the Self-Administered Leeds Assessment of Neuropathic Signs and Symptoms (S-LANSS), and a satisfaction questionnaire. NP was defined as an S-LANSS score of 12 or more.

RESULTS

Of 89 patients who met the inclusion criteria, data for 63 (71%) patients (47 women; mean age 67 [SD 8] y) were used for analysis. Of these 63, 9 (14%) were identified as having NP. None had a report of failure of prosthesis or other surgical complications according to most recent medical records. There was no relationship between preoperative patient characteristics and development of NP. However, the NP group on average had a higher report of stiffness (p=0.020), physical dysfunction (p=0.019), and pain (p=0.050) at 1 year after surgery. Cross-sectional comparisons showed higher levels of pain (p=0.001), stiffness (p=0.008), physical dysfunction (p=0.003), and depression (p=0.005) and lower satisfaction (p=0.018) at the time of the survey than the patients without NP.

CONCLUSION

The estimated prevalence of NP was 14%. Patients with NP reported higher levels of disability as early as 1 year after surgery. They remained more disabled, with a higher level of depression and less satisfaction, at an average of 5 years after surgery.

The painDETECT project - far more than a screening tool on neuropathic pain

Background and objectives The painDETECT questionnaire (PD-Q), a simple and reliable screening questionnaire of neuropathic pain, was developed in 2004 in cooperation with the German Research Network on Neuropathic Pain. The initial aim was to implement quality management and to improve the situation of neuropathic pain (NeP) patients in Germany. The PD-Q proved immediately successful and was translated into and validated in multiple languages. Subsequently a comprehensive electronic system (PD) comprising various validated questionnaires with regard to pain typical comorbidities, such as function, sleep, mood or anxiety, was implemented Germany wide. We aimed to provide a comprehensive overview about the development and validation as well as the application of the PD-Q in various clinical conditions. Methods This overview is based on a literature search on English full-text papers using the term 'painDETECT' in Medline and PubMed covering the time period from 2006 to September 2015, amended with further publications cited in the retrieved publications or provided by the questionnaire developers. Results PD-Q as screening tool for NeP described in patients with lower back pain (8 studies), rheumatoid arthritis and osteoarthritis (10), thoracotomy (2 studies), tumor diseases (4 studies), fibromyalgia (4 studies), diverse musculoskeletal conditions (12 studies) and diverse other conditions (10 studies). In addition, the PD-Q was used in 9 studies that investigated the effect of drugs for the treatment of patients with a NeP component. Conclusion To date more than 300,000 patients were assessed, providing the basis for one of the world's largest datasets for chronic pain. Among others the extensive pool of PD-Q data triggered the idea of subgrouping patients on the basis of their individual sensory profiles which might in the future lead to a stratified treatment approach and ultimately to personalized therapy. Started as a healthcare utilization project in Germany, the PD-Q is nowadays used for clinical and research purposes around the world.

Pain after total knee arthroplasty: a narrative review focusing on the stratification of patients at risk for persistent pain

The patient with a painful arthritic knee awaiting total knee arthroplasty (TKA) requires a multidisciplinary approach. Optimal control of acute post-operative pain and the prevention of chronic persistent pain remains a challenge. The aim of this paper is to evaluate whether stratification of patients can help identify those who are at particular risk for severe acute or chronic pain. Intense acute post-operative pain, which is itself a risk factor for chronic pain, is more common in younger, obese female patients and those suffering from central pain sensitisation. Pre-operative pain, in the knee or elsewhere in the body, predisposes to central sensitisation. Pain due to osteoarthritis of the knee may also trigger neuropathic pain and may be associated with chronic medication like opioids, leading to a state of nociceptive sensitisation called 'opioid-induced hyperalgesia'. Finally, genetic and personality related risk factors may also put patients at a higher risk for the development of chronic pain. Those identified as at risk for chronic pain would benefit from specific peri-operative management including reduction in opioid intake pre-operatively, the peri-operative use of antihyperalgesic drugs such as ketamine and gabapentinoids, and a close post-operative follow-up in a dedicated chronic pain clinic.

Subacute Pain as a Predictor of Long-Term Pain Following Orthopedic Surgery: An Australian Prospective 12 Month Observational Cohort Study

The aim of this study was to document the level of pain and functionality in the 12 months following orthopedic surgery and identify if high pain levels following discharge were associated with pain persisting at 12 months.An observational prospective cohort study was undertaken, following 87 patients (mean age 62.4 years [18-92]; 47.1% male) who required orthopedic surgery at the Royal Hobart Hospital, Australia. Following an initial survey, patients were telephoned at 10 days, 6 weeks, 3 months, and 12 months after discharge.Postdischarge pain levels were high with 97.4% of patients suffering pain at 10 days, 81.2% at 6 weeks and 79.5% at 3 months. Pain affected the ability to undertake activities of daily living (ADLs) for 32.7% and 20.0% of patients at 10 days and 6 weeks, respectively. Twelve months after discharge, 65.5% of patients reported pain persisting at the surgical site, with 29.9% of all patients suffering moderate-severe incidental pain; and nearly one quarter of patients reported pain affected their sleep or ADLs. Average pain levels rated as moderate-severe at 10 days (P = 0.01) and 6 weeks (P = 0.02) and pain of neuropathic origin at 3 months (30.2% vs 10.3% P = 0.03) and 12 months (30.4% vs 4.9% P = 0.01) were associated with persistent pain at 12 months.Pain in the period following discharge from hospital is significant and undermanaged. Previous studies has shown that that acute pain, particularly in the first 48 hours following surgery is a predictor for long-term pain after surgery. This study adds to the current literature by showing that pain in the subacute period, following discharge from hospital is also associated with the pain persisting at 12 months. These findings have important implications for improving quality of life as well as potentially preventing persistent pain with increased follow-up and more intensive management of post-discharge pain.

Persistent post-surgical pain and neuropathic pain after total knee replacement

AIM: To study the prevalence of persistent post-surgical pain (PPSP) and neuropathic pain (NP) after total knee replacement (TKR).

METHODS: MEDLINE and Embase databases were searched for articles published until December 2014 in English language. Published articles were included if they referred to pain that lasts at least 3 mo after primary TKR for knee osteoarthritis, and measured pain with pain specific instruments. Studies that referred to pain caused by septic reasons and implant malalignment were excluded. Both prospective and retrospective studies were included and only 14 studies that match the inclusion criteria were selected for this review.

RESULTS: The included studies were characterized by the heterogeneity on the scales used to measure pain and pre-operative factors related to PPSP and NP. The reported prevalence of PPSP and NP seems to be relatively high, but it varies among different studies. There is also evidence that the prevalence of post-surgical pain is related to the scale used for pain measurement. The prevalence of PPSP is ranging at 6 mo from 16% to 39% and at 12 mo from 13.1% to 23% and even 38% of the patients. The prevalence of NP at 6 mo post-operatively is ranging from 5.2% to 13%. Pre-operative factors related to the development of PPSP also differ, including emotional functioning, such as depression and pain catastrophizing, number of comorbidities, pain problems elsewhere and operations in knees with early grade of osteoarthritis.

CONCLUSION: No firm conclusions can be reached regarding the prevalence of PPSP and NP and the related factors due to the heterogeneity of the studies.