Assessment of chronic postsurgical pain after knee replacement: a systematic review

Assessing pain management in total joint arthroplasty using the Detroit interventional pain assessment scale-A prospective cohort study

BACKGROUND

Total joint arthroplasty (TJA) is an effective treatment for end-stage osteoarthritis, but postoperative pain has been poorly managed. The purpose of this study was to (1) assess how much narcotic medication was prescribed after TJA; (2) assess if patients were satisfied with their pain management; (3) compare these same data between total hip arthroplasty (THA)/total knee arthroplasty (TKA); (4) compare these same data between preoperative opioid users/opioid-naïve patients.

METHODS

An IRB-approved prospective study was conducted at a US academic joint replacement practice. Patients were evaluated by an independent observer at three weeks, three months, and six months postoperatively using the Detroit Interventional Pain Assessment (DIPA) scale. Patients verbally rated their pain with their current medication regimen as 0 (no pain), 1 (tolerable pain), or 2 (intolerable pain) on the DIPA scale. Narcotic usage was verified by the Michigan Automated Prescription System (MAPS). Patients were divided into THA, TKA, previously on opioids, and opioid-naïve groups. Provider efficiency scores reflected pain management satisfaction and were calculated as the percentage of patients reporting no pain or tolerable pain.

RESULTS

Out of 200 patients, the percentage of patients using narcotics and their daily usage (MMEs) significantly decreased from 75.5% (27.5 MMEs) at three weeks to 42.9% (5.3 MMEs) at six months (P < 0.001). In 80% of patients, narcotics taken at six months were prescribed by outside providers. Significantly fewer patients used narcotics at six months for THA (15.4%) compared to TKA (52.7%) (P < 0.021). There was a significant difference in daily narcotic usage between patients who took narcotics preoperatively (22.9 MMEs) and opioid-naïve ones (13.4 MMEs) (P < 0.001). Provider efficiency scores were best at three weeks (76.6%) and three months (70%) but declined at six months (57.2%).

CONCLUSIONS

Narcotic tapering practices were observed as postoperative daily narcotic intake decreased across six months. However, outside providers prescribed 80% of narcotics at six months, necessitating a better-coordinated practice with surgeons. Patients taking preoperative narcotics experienced higher daily MME requirements than their opioid-naïve counterparts. In terms of the percentage of patients on narcotics, THA is a better procedure for tapering patients off narcotics by six months.

9. Chronic knee pain

INTRODUCTION

Chronic knee pain is defined as pain that persists or recurs over 3 months. The most common is degenerative osteoarthritis (OA). This review represents a comprehensive description of the pathology, diagnosis, and treatment of OA of the knee.

METHODS

The literature on the diagnosis and treatment of chronic knee pain was retrieved and summarized. A modified Delphi approach was used to formulate recommendations on interventional treatments.

RESULTS

Patients with knee OA commonly present with insidious, chronic knee pain that gradually worsens. Pain caused by knee OA is predominantly nociceptive pain, with occasional nociplastic and infrequent neuropathic characteristics occurring in a diseased knee. A standard musculoskeletal and neurological examination is required for the diagnosis of knee OA. Although typical clinical OA findings are sufficient for diagnosis, medical imaging may be performed to improve specificity. The differential diagnosis should exclude other causes of knee pain including bone and joint disorders such as rheumatoid arthritis, spondylo- and other arthropathies, and infections. When conservative treatment fails, intra-articular injections of corticosteroids and radiofrequency (conventional and cooled) of the genicular nerves have been shown to be effective. Hyaluronic acid infiltrations are conditionally recommended. Platelet-rich plasma infiltrations, chemical ablation of genicular nerves, and neurostimulation have, at the moment, not enough evidence and can be considered in a study setting. The decision to perform joint-preserving and joint-replacement options should be made multidisciplinary.

CONCLUSIONS

When conservative measures fail to provide satisfactory pain relief, a multidisciplinary approach is recommended including psychological therapy, integrative treatments, and procedural options such as intra-articular injections, radiofrequency ablation, and surgery.

Ultrasound-guided dexmedetomidine combination with modified high fascia iliaca compartment block for arthroscopic knee surgery: what is the optimal dose of dexmedetomidine?

BACKGROUND

Total knee arthroplasty (TKA) is a common orthopedic procedure for end-stage knee osteoarthritis. Although effective in relieving pain and improving function, postoperative pain is still a common and distressing problem for many patients. This study aims to investigate efficacy of combined administration of dexmedetomidine and modified high fascia iliaca compartment block (H-FICB) in managing acute and chronic pain after TKA, as well as to identify the optimal dosage of dexmedetomidine.

METHODS

A double-blind, randomized controlled trial was conducted to evaluate the effects of dexmedetomidine in patients undergoing TKA. A total of 96 patients undergoing TKA were randomly assigned to one of three groups, were treated with different doses of dexmedetomidine All groups received H-FIB. Pain scores, opioid consumption, side effects, and quality of life were recorded 48 h postoperatively.

RESULTS

The intraoperative consumption of remifentanil and propofol in Group Db was significantly reduced compared with that in Group D0 and Da (P < 0.05). Compared with D0 and Da group, Db group had the lowest number of rescue analgesia, analgesia time and morphine accumulative dosage 48 h after operation (P < 0.05). The Db group had the lowest scores on the numerical rating scale at rest (P < 0.05) and during movement (P < 0.01), followed by the Da group and then the D0 group. Additionally, the incidence of nausea and vomiting was significantly reduced in the Db group (P < 0.05). Furthermore, the Db group had the lowest incidence of chronic pain (P < 0.05).

DISCUSSION

In comparison to the other two groups, the administration of combined dexmedetomidine and H-FIB resulted in a significant reduction in pain scores, opioid consumption, and side effects. The optimal dosage of dexmedetomidine was determined to be 1 μg/kg, which provided the most favorable pain relief with minimal adverse effects.

Construction and Validation of Machine Learning Algorithms to Predict Chronic Post-Surgical Pain Among Patients Undergoing Total Knee Arthroplasty

BACKGROUND

Chronic post-surgical pain (CPSP) is a common but undertreated condition with a high prevalence among patients undergoing total knee arthroplasty (TKA). An effective model for CPSP prediction has not been established yet.

AIMS

To construct and validate machine learning models for the early prediction of CPSP among patients undergoing TKA.

DESIGN

A prospective cohort study.

PARTICIPANTS/SUBJECTS

A total of 320 patients in the modeling group and 150 patients in the validation group were recruited from two independent hospitals between December 2021 and July 2022. They were followed up for 6 months to determine the outcomes of CPSP through telephone interviews.

METHODS

Four machine learning algorithms were developed through 10-fold cross-validation for five times. In the validation group, the discrimination and calibration of the machine learning algorithms were compared by the logistic regression model. The importance of the variables in the best model identified was ranked.

RESULTS

The incidence of CPSP in the modeling group was 25.3%, and that in the validation group was 27.6%. Compared with other models, the random forest model achieved the best performance with the highest C-statistic of 0.897 and the lowest Brier score of 0.119 in the validation group. The top three important factors for predicting CPSP were knee joint function, fear of movement, and pain at rest in the baseline.

CONCLUSIONS

The random forest model demonstrated good discrimination and calibration capacity for identifying patients undergoing TKA at high risk for CPSP. Clinical nurses would screen out high-risk patients for CPSP by using the risk factors identified in the random forest model, and efficiently distribute preventive strategy.

Comparison of conventional and cooled radiofrequency treatment of the genicular nerves versus sham procedure for patients with chronic knee pain: protocol for a multicentre, double-blind, randomised controlled trial (COGENIUS)

INTRODUCTION

The prevalence of chronic knee pain is increasing. Osteoarthritis (OA) and persistent postsurgical pain (PPSP) are two important causes of knee pain. Chronic knee pain is primarily treated with medications, physiotherapy, life-style changes and intra-articular infiltrations. A radiofrequency treatment (RF) of the genicular nerves is a therapeutical option for refractory knee pain. This study investigates the effectiveness and cost-effectiveness of conventional and cooled RF in patients suffering from chronic, therapy resistant, moderate to severe knee pain due to OA and PPSP.

METHODS AND ANALYSIS

The COGENIUS trial is a double-blinded, randomised controlled trial with 2-year follow-up. Patients and outcome assessors are blinded. Patients will be recruited and treated in Belgium and the Netherlands. All PPSP after a total knee prothesis and OA patients (grades 2-4) will undergo a run-in period of 1-3 months where conservative treatment will be optimised. After the run-in period, 200 patient per group will be randomised to conventional RF, cooled RF or a sham procedure following a 2:2:1 ratio. The analysis will include a comparison of the effectiveness of each RF treatment with the sham procedure and secondarily between conventional and cooled RF. All comparisons will be made for each indication separately. The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index score at 6 months. Other outcomes include knee pain, physical functionality, health-related quality of life, emotional health, medication use, healthcare and societal cost and adverse events up to 24 months postintervention.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the University of Antwerp (Number Project ID 3069-Edge 002190-BUN B3002022000025), the Ethics committee of Maastricht University (Number NL80503.068.22-METC22-023) and the Ethics committee of all participating hospitals. Results of the study will be published in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05407610.

Effectiveness of cognitive behavioral therapy for patients after total knee arthroplasty: a systematic review and meta-analysis

Total knee arthroplasty (TKA) is considered a common surgical option in patients with end-stage osteoarthritis of the knee. This systematic review and meta-analysis aimed to determine the effectiveness of cognitive behavioral therapy (CBT) for patients after TKA. PubMed, EMBASE, the Cochrane Library, Web of Science and CINAHL were searched for randomized controlled trials (RCTs) from inception to 20 August 2021. Included studies were evaluated with the Cochrane risk-of-bias tool. Six RCTs were included. Our study results demonstrated that a significant reduction in pain catastrophing was seen in patients receiving CBT at post-intervention (SMD -0.48, 95% CI = -0.72 to -0.23, I2 17.2%, p = 0.00) but not in 3-month or 12-month follow-up. There were no significant differences between CBT and usual-care patients regarding pain intensity or knee function at different time-points. This is the first time that meta-analysis has been conducted to determine the effectiveness of CBT for patients after TKA. It is necessary to conduct longer follow-ups, include larger samples and conduct rigorous RCTs to further explore this issue.

Effects of a home-based, exergaming intervention on physical function and pain after total knee replacement in older adults: a randomised controlled trial

Objectives

To investigate the effects of 4 months of customised, home-based exergaming on physical function and pain after total knee replacement (TKR) compared with standard exercise protocol.

Methods

In this non-blinded randomised controlled trial, 52 individuals aged 60-75 years undergoing TKR were randomised into an exergaming (intervention group, IG) or a standard exercising group (control group, CG). Primary outcomes were physical function and pain measured before and after (2 months and 4 months) surgery using the Oxford Knee Score (OKS) and Timed Up and Go (TUG) test. Secondary outcomes included measures of the Visual Analogue Scale, 10m walking, short physical performance battery, isometric knee extension and flexion force, knee range of movement and satisfaction with the operated knee.

Results

Improvement in mobility measured by TUG was greater in the IG (n=21) at 2 (p=0.019) and 4 months (p=0.040) than in the CG (n=25). The TUG improved in the IG by -1.9 s (95% CI, -2.9 to -1.0), while it changed by -0.6 s (95% CI -1.4 to 0.3) in the CG. There were no differences between the groups in the OKS or secondary outcomes over 4 months. 100% of patients in the IG and 74% in the CG were satisfied with the operated knee.

Conclusion

In patients who have undergone TKR, training at home with customised exergames was more effective in mobility and early satisfaction and as effective as standard exercise in pain and other physical functions. In both groups, knee-related function and pain improvement can be considered clinically meaningful.

Trial registration number

NCT03717727.

To be mindful of the breath or pain: Comparing two brief preoperative mindfulness techniques for total joint arthroplasty patients

OBJECTIVE

Total joint arthroplasty (TJA) often reduces pain and improves function, but it is also a risk factor for the development of chronic pain and postoperative opioid use. To protect against these untoward postsurgical outcomes, TJA patients need better, non-pharmacological pain management strategies. This study compared two, promising, mindfulness-based pain management techniques.

METHOD

We conducted a single-site, three-arm, parallel-group randomized controlled study conducted at an orthopedic clinic among patients undergoing TJA of the knee or hip. TJA patients (N = 118, M age = 65, female = 73, Caucasian = 110) were randomized to either a preoperative mindfulness of breath (MoB), mindfulness of pain (MoP), or cognitive-behavioral pain psychoeducation (CB) intervention, approximately 3 weeks before surgery. Each intervention was delivered in a single, 20-min session during a 2-hr, preoperative education program. Change in pain intensity was the sole preoperative outcome. The postoperative outcomes, pain intensity, pain interference, and opioid use were assessed on the 2nd, 3rd, 7th, 14th, 21st, and 28th postoperative days.

RESULTS

MoB was found to most effectively decrease preoperative pain scores, F(2, 89) = 5.28, p = .007, while MoP resulted in the least amount of postoperative pain intensity, F(8, 94) = 3.21, p = .003, and interference, F(8, 94) = 2.52, p = .016). Both MoB and MoP decreased postoperative opioid use relative to CB, F(8, 83) = 16.66, p < .001.

CONCLUSION

A brief preoperative MBI may be able to prevent both postoperative pain and opioid use. Moreover, the MBIs used in this study are highly feasible, capable of being delivered by nearly any healthcare provider, and requiring minimal clinic time given their brevity. As such, embedding MBIs in surgical care pathways has considerable potential. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Safety and Efficacy of Perioperative Intravenous Meloxicam for Moderate-to-Severe Pain Management in Total Knee Arthroplasty: A Randomized Clinical Trial

Objective

To evaluate the effect of perioperative meloxicam IV 30 mg on opioid consumption in primary total knee arthroplasty (TKA).

Design

Multicenter, randomized, double-blind, placebo-controlled trial.

Subjects

In total, 181 adults undergoing elective primary TKA.

Methods

Subjects received meloxicam 30 mg or placebo via an IV bolus every 24 hours, the first dose administered prior to surgery as part of a multimodal pain management protocol. The primary efficacy parameter was total opioid use from end of surgery through 24 hours.

Results

Meloxicam IV was associated with less opioid use versus placebo during the 24 hours after surgery (18.9 ± 1.32 vs 27.7 ± 1.37 mg IV morphine equivalent dose; P < 0.001) and was superior to placebo on secondary endpoints, including summed pain intensity (first dose to 24 hours postdosing, first dose to first assisted ambulation, and first dose to discharge) and opioid use (48–72 hrs., 0–48 hrs., 0–72 hrs., hour 0 to end of treatment, and the first 24 hours after discharge). Adverse events (AEs) were reported for 69.9% and 92.0% of the meloxicam IV and placebo groups, respectively; the most common AEs were nausea (40% vs. 59%), vomiting (16% vs 22%), hypotension (14% vs 15%), pruritus (15% vs 11%), and constipation (11% vs 13%).

Conclusions

Perioperative meloxicam IV 30 mg as part of a multimodal analgesic regimen for elective primary TKA reduced opioid consumption in the 24-hour period after surgery versus placebo and was associated with a lower incidence of AEs typically associated with opioid use.

Identifying Patterns and Predictors of Prescription Opioid Use After Total Joint Arthroplasty

INTRODUCTION

Total hip arthroplasty and total knee arthroplasty account for over 1 million procedures annually. Opioids are the mainstay of postoperative pain management for these patients. In this context, the objective of this study was to determine patterns of use and factors associated with early discontinuation of opioids after total joint arthroplasty (TJA).

METHODS

TRICARE claims data (2006-2014) were queried for adult (18-64 years) patients who underwent total hip arthroplasty or total knee arthroplasty. Prescription opioid use was identified from 6 months before and 6 months after surgical intervention. Prior opioid use was categorized as naïve, exposed (with non-sustained use), and sustained (6 month continuous use before surgery). Cox proportional-hazards models were used to identify factors associated with opioid discontinuation following TJA.

RESULTS

Among the 29,767 patients included in the study, 15,271 (51.3%) had prior opioid exposure and 3,740 (12.5%) were sustained opioid users. At 6 months after the surgical intervention, 3,171 (10.6%) continued opioid use, 3.3% were among opioid naïve, 10.2% among exposed, and 33.3% among sustained users. In risk-adjusted models, prior opioid exposure (hazards ratio: 0.65, 95% CI: 0.62-0.67) and sustained prior use (hazards ratio: 0.33, 95% CI: 0.31-0.35) were the strongest predictors of lower likelihood of opioid discontinuation. Lower socio-economic status, depression, and anxiety were also strong predictors.

CONCLUSION

Prior opioid exposure was strongly associated with continued opioid dependence after TJA. Although one-third of prior sustained users continued use after surgery, approximately 10% of previously exposed patients became sustained users, making them the prime candidates for targeted interventions to reduce the likelihood of sustained opioid use after TJA.

Screening to identify postoperative pain and cross-sectional associations between factors identified in this process with pain and function, three months after total knee replacement

Objective

To describe the screening and recruitment process of a randomized trial and evaluate associations with knee pain and function 3 months after total knee replacement (TKR).

Methods

In order to screen for a multicenter trial, a total of 5,036 patients were sent the Oxford Knee Score (OKS) questionnaire 10 weeks post‐TKR. Patients who reported pain in their replaced knee (score of ≤14 on the OKS pain component) completed a second OKS questionnaire 12 weeks post‐TKR. Those patients who were still experiencing pain 12 weeks post‐TKR completed a detailed questionnaire 13 weeks post‐TKR. These data were used to characterize pain in a cross‐sectional analysis. Multivariable regression was performed in order to identify factors associated with pain and function at 13 weeks post‐TKR.

Results

We received OKS questionnaires from 3,058 of 5,063 TKR patients (60%), and 907 of the 3,058 (30%) reported pain in their replaced knee 10 weeks post‐TKR. By 12 weeks, 179 of 553 patients (32%) reported improved pain (score of >14 on the OKS pain component). At 13 weeks, 192 of 363 patients (53%) who completed a detailed questionnaire reported neuropathic pain, 94 of 362 (26%) reported depression symptoms, and 95 of 363 (26%) anxiety symptoms. More severe pain at 13 weeks postoperatively was associated with poorer general health, poorer physical health, more pain worry, and lower satisfaction with surgery outcome. More severe functional limitation was associated with higher levels of depression, more pain worry, lower satisfaction with surgery outcome, and higher pain acceptance.

Conclusion

Screening after TKR identified individuals with pain. We identified several potential targets (physical and mental health outcomes, acceptance of pain, and quality of life) for tailored intervention to improve outcomes for patients. Future trials of multidisciplinary interventions warranted.

Preoperative dexamethasone for pain relief after total knee arthroplasty: A randomised controlled trial

BACKGROUND

Corticosteroids can reduce pain but the optimal dose and safety profiles are still uncertain.

OBJECTIVE

This study aimed to evaluate two different doses of dexamethasone for pain management and their side effects after total knee arthroplasty.

DESIGN

A prospective randomised, controlled trial.

SETTING

A tertiary teaching hospital in Hong Kong.

PATIENTS

One hundred and forty-six patients were randomly allocated to one of three study groups.

INTERVENTIONS

Before operation, patients in group D8, D16 and P received dexamethasone 8 mg, dexamethasone 16 mg and placebo (0.9% saline), respectively.

MAIN OUTCOME MEASURES

The primary outcome was postoperative pain score. Secondary outcomes were opioid consumption, physical parameters of the knees and side effects of dexamethasone.

RESULTS

Compared with placebo, group D16 patients had significantly less pain during maximal active flexion on postoperative day 3 [-1.3 (95% CI, -2.2 to -0.31), P = 0.005]. There was also a significant dose-dependent trend between pain scores and dexamethasone dose (P = 0.002). Compared with placebo, patients in group D16 consumed significantly less opioid [-6.4 mg (95% CI, -11.6 to -1.2), P = 0.025] and had stronger quadriceps power on the first three postoperative days (all P < 0.05). They also had significantly longer walking distance on postoperative day 1 [7.8 m ([95% CI, 0.85 to 14.7), P = 0.023] with less assistance during walking on the first two postoperative days (all P < 0.029) and significantly better quality-of-recovery scores on postoperative day 1 (P = 0.018). There were significant dose-dependent trends between all the above parameters and dexamethasone dose (all P < 0.05). No significant differences were found in the incidence of chronic pain or knee function 3, 6 and 12 months postoperatively.

CONCLUSION

Dexamethasone 16 mg given before total knee arthroplasty led to a reduction in postoperative pain, less opioid consumption, stronger quadriceps muscle power, better mobilisation and better overall quality-of-recovery after operation. No long-term improvement in reduction in pain and function of the knee was found.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02767882.

Patient satisfaction and perception of success after total knee arthroplasty are more strongly associated with patient factors and complications than surgical or anaesthetic factors

PURPOSE

A proportion of TKA recipients following TKA are dissatisfied with their outcome. Our hypothesis is that patient satisfaction with TKA and perception of success of surgery are associated with patient comorbidities and overall health status, surgical and anaesthetic techniques as well as processes of post-operative care after TKA. The aims were to (i) measure the incidence of patient unfavourable outcomes-defined as dissatisfaction with the surgery or lack of joint-specific global improvement-1 year after TKA, and to explore the differences between these two outcomes of interest; (ii) assess the relationship between the development of these unfavourable outcomes and patient-reported knee function and overall quality of life; (iii) explore the associations between pre- and peri-operative variables and the development of these unfavourable outcomes 1 year after TKA.

METHODS

This study includes analysis of data from a prospective cohort of 1017 TKA recipients. Pre-operative patient variables, surgical and acute-care data were collected. The Oxford knee score and the global perception of improvement were used to assess satisfaction and success 365 days post-surgery.

RESULTS

From 1017 patients (56% female), mean age 68 years and BMI 32, 68 pts (7%) were dissatisfied with the outcome of surgery, 141 pts (14%) believed surgery was unsuccessful 1 year after TKA. A negative outcome was noted in 151 (15%) patients for either satisfaction or success, and 58 (6%) of patients reported neither good satisfaction nor success after surgery. Dissatisfied patients reported worse mean OKS (26.4 [SD 8.03] vs 42.3 [SD 5.21], p < 0.001) and mean EQ VAS (64.9 [SD 19.49] vs 81.8 [SD 14.38], p < 0.001) than satisfied patients. Patients who reported unsuccessful surgery also showed significantly lower mean OKS (30.9 [SD 9.29] vs 42.9 [SD 4.39], p < 0.001) and mean EQ VAS (68.2 [SD 18.61] vs 82.7 [SD 13.77], p < 0.001). Univariate analysis of predictors of unfavourable outcome post-TKA showed that financial status, obstructive sleep apnoea (OSA), ASA class > 2 and not resurfacing the patella were factors associated with the development of dissatisfaction with TKA and with patient perceived unsuccessful results of TKA. Multivariable logistic regression of patient satisfaction and success of TKA showed that compensation cases (OR 26.91, p < 0.001 for dissatisfaction and OR 11.49, p = 0.001 for unsuccessful TKA), obstructive sleep apnoea (OR 2.18, p = 0.04 for dissatisfaction and OR 1.82, p = 0.04 for unsuccessful TKA), ASA grade > 2 (OR 1.83, p = 0.04 for dissatisfaction and OR 1.57, p = 0.03 for unsuccessful TKA)and the development of a complication after TKA (OR 3.4, p < 0.001 for dissatisfaction and OR 2.39, p < 0.001 for unsuccessful TKA) were associated with the development of a negative outcome in both groups. Patella preservation (OR 1.96, p = 0.03) was associated with dissatisfaction, whereas the use of cruciate retaining femoral prosthesis was associated with less successful results of TKA (OR 1.78, p = 0.009).

CONCLUSIONS

An unfavourable outcome occurs in approximately 7-15% of patients following TKA. The incidence varies with how an unfavourable result is defined and many factors are associated with this outcome though prosthetic design or patella resurfacing do not appear to be important.

Effects of presurgical interventions on chronic pain after total knee replacement: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

Nearly 100 000 primary total knee replacements (TKR) are performed in the UK annually. The primary aim of TKR is pain relief, but 10%-34% of patients report chronic pain. The aim of this systematic review was to evaluate the effectiveness of presurgical interventions in preventing chronic pain after TKR.

DESIGN

MEDLINE, Embase, CINAHL, The Cochrane Library and PsycINFO were searched from inception to December 2018. Screening and data extraction were performed by two authors. Meta-analysis was conducted using a random effects model. Risk of bias was assessed using the Cochrane tool and quality of evidence was assessed by Grading of Recommendations Assessment, Development and Evaluation.

PRIMARY AND SECONDARY OUTCOMES

Pain at 6 months or longer; adverse events.

INTERVENTIONS

Presurgical interventions aimed at improving TKR outcomes.

RESULTS

Eight randomised controlled trials (RCTs) with data from 960 participants were included. The studies involved nine eligible comparisons. We found moderate-quality evidence of no effect of exercise programmes on chronic pain after TKR, based on a meta-analysis of 6 interventions with 229 participants (standardised mean difference 0.20, 95% CI -0.06 to 0.47, I²=0%). Sensitivity analysis restricted to studies at overall low risk of bias confirmed findings. Another RCT of exercise with no data available for meta-analysis showed no benefit. Studies evaluating combined exercise and education intervention (n=1) and education alone (n=1) suggested similar findings. Adverse event data were reported by most studies, but events were too few to draw conclusions.

CONCLUSIONS

We found low to moderate-quality evidence to suggest that neither preoperative exercise, education nor a combination of both is effective in preventing chronic pain after TKR. This review also identified a lack of evaluations of other preoperative interventions, such as multimodal pain management, which may improve long-term pain outcomes after TKR.

PROSPERO REGISTRATION NUMBER

CRD42017041382.

[Predictors for persistent pain and dissatisfaction after total knee arthroplasty]

BACKGROUND

A substantial number of patients patients suffer from persistent pain or are unsatisfied after total knee arthroplasty (TKA).

OBJECTIVES

This work aims to present the frequency of postoperative persistent pain and/or dissatisfaction as well as known causes and predictors.

MATERIALS AND METHODS

The current literature is studied regarding the subject and is reviewed narratively.

RESULTS

Most postoperative problems did not arise from operation details, but from patient-related criteria, a lack of patient education and selection. The satisfaction correlates most strongly with the reduction of preoperative pain.

CONCLUSION

For a successful TKA, care should be taken that the following aspects are met preoperatively: clinically and radiologically advanced osteoarthritis, a patient age preferably older than 60 years, sufficient psychosocial resources to cope with postoperative stress, no opioid medication and realistic expectations after TKA. Postoperatively, patients with persistent pain or dissatisfaction should be checked for any prosthesis-related problems. If no prosthesis-related problems could be detected, the patients should be referred for interdisciplinary therapies.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

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

Prevalence and Predictors of Symptom Resolution and Functional Restoration in the Index Knee After Knee Arthroplasty: A Longitudinal Study

OBJECTIVES

To determine the prevalence of a 1- to 2-year postsurgical pain-free state and pain plus symptom-free state as well as functional restoration after knee arthroplasty (KA) and to identify predictors of these outcomes.

DESIGN

Cohort study.

SETTING

Communities of 4 sites.

PARTICIPANTS

Consecutive participants (N=383) who underwent KA on at least 1 knee during the first 8 years of the study (mean age, 67.95±8.5y; 61.4% women; n=235).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A composite pain score included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain scale and 2 generic pain rating scales. Composite pain plus other symptoms scores included 3 pain scales, a stiffness scale, and, in addition, the Knee injury and Osteoarthritis Outcome Score Symptoms scale. The WOMAC Function scale was used to quantify functional status. Prevalence estimates and predictors of a pain-free state, symptom-free state, and a fully functioning state were determined.

RESULTS

A sample of 383 participants with KA was studied, and of these, 34.1% (95% confidence interval [CI], 29.3%-39.2%; n=131) had a composite score of 0 for pain. A total of 14.1% (95% CI, 10.8%-18.1%; n=54) had a composite score of 0, indicating a symptom-free state, whereas 29.0% (95% CI, 24.4%-34.0%; n=111) achieved a score of 0 on the WOMAC Function scale.

CONCLUSIONS

The prevalence of complete pain relief was 34%, the prevalence of complete pain and symptom relief was 14%, and the prevalence of complete functional restoration was 29% after KA. Participants who are older and with lower (better) WOMAC Pain scores were more likely to be pain-free after surgery. These data collected from a community-based sample have the potential to inform clinicians screening patients for KA consultation in a shared decision-making discussion to better align patient expectations with the most likely outcome.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

ClinicalTrials.gov NCT01620983.

A unified multi-level model approach to assessing patient responsiveness including; return to normal, minimally important differences and minimal clinically important improvement for patient reported outcome measures

OBJECTIVE

This article reviews and compares four commonly used approaches to assess patient responsiveness with a treatment or therapy (return to normal (RTN), minimal important difference (MID), minimal clinically important improvement (MCII), OMERACT-OARSI [Outcome Measures in Rheumatology-Osteoarthris Reseach Society International] (OO)) and demonstrates how each of the methods can be formulated in a multilevel modelling (MLM) framework.

DESIGN

Cohort study.

SETTING

A cohort of patients undergoing total hip and knee replacement were recruited from a single UK National Health Service hospital.

POPULATION

400 patients from the Arthroplasty Pain Experience cohort study undergoing total hip (n=210) and knee (n=190) replacement who completed the Intermittent and Constant Osteoarthritis Pain questionnaire prior to surgery and then at 3, 6 and 12 months after surgery.

PRIMARY OUTCOMES

The primary outcome was defined as a response to treatment following total hip or knee replacement. We compared baseline scores, change scores and proportion of individuals defined as 'responders' using traditional and MLM approaches with patient responsiveness.

RESULTS

Using existing approaches, baseline and change scores are underestimated, and the variance of baseline and change scores overestimated in comparison with MLM approaches. MLM increases the proportion of individuals defined as responding in RTN, MID and OO criteria compared with existing approaches. Using MLM with the MCII criteria reduces the number of individuals identified as responders.

CONCLUSION

MLM improves the estimation of the SD of baseline and change scores by explicitly incorporating measurement error into the model and avoiding regression to the mean when making individual predictions. Using refined definitions of responsiveness may lead to a reduction in misclassification when attempting to predict who does and does not respond to an intervention and clarifies the similarities between existing methods.

Comprehensive Analysis of Pain Management after Total Knee Arthroplasty

Total knee arthroplasty (TKA) has been much improved recently and it is regarded as one of the most common and successful surgical procedures that provides pain relief and improves function in patients with severe knee arthritis. However, recent studies have reported that 15%–20% of patients are not satisfied after TKA without evident clinical or radiological findings and the most common causes of patient dissatisfaction include residual pain and limited function. The evaluation and treatment of painful TKA relies on a thorough understanding of the origin by careful evaluation, and a systematic approach is essential to efficiently and effectively resolve the pain. Periarticular injections (PAIs) and nerve blocks are gaining popularity because they are associated with less side effects than systemic regimens. The analgesic efficacy and safety of PAI compared with nerve blocks for postoperative pain management still remain controversial. Therefore, more study is needed to determine if any changes in the regimen of the injection or technique could provide added benefit to long-term functional improvement beyond the perioperative period.

Dry Needling Combined With Physical Therapy in Patients With Chronic Postsurgical Pain Following Total Knee Arthroplasty: A Case Series

Study Design Case series. Background This case series describes a combined program of dry needling and therapeutic exercise in a small group of patients with persistent pain following total knee arthroplasty (TKA). Case Description Fourteen patients who underwent TKA had persistent postsurgical pain and myofascial trigger points that were nonresponsive to treatment with conventional physical therapy and/or medication. The patients received a weekly dry needling treatment in combination with therapeutic exercises for 4 weeks. Pain perception was assessed preintervention and postintervention with a visual analog scale and function was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index, 6-minute walk test, timed up-and-go test, 30-second chair-stand test, and knee joint range of motion. Outcomes After TKA, the patients had a mean ± SD symptom duration of 6.3 ± 3.1 months. Subsequent to dry needling, patients reported a significant mean ± SD decrease in pain intensity from 55.6 ± 6.6 to 19.3 ± 5.6 (P<.001) and improvements in Western Ontario and McMaster Universities Osteoarthritis Index scores from 10.1 ± 0.8 to 4.9 ± 1.0 for pain (P<.001), from 5.3 ± 0.4 to 2.4 ± 1.2 for stiffness (P<.001), and from 36.7 ± 2.0 to 20.1 ± 3.2 for function (P<.001). Knee flexion increased from a mean ± SD of 82.7° ± 5.2° to 93.3° ± 4.3° (P<.001), and joint extension improved from 15.8° ± 2.9° to 5.3° ± 2.4° (P<.05). The 6-minute walk test also showed improvement in postintervention values from a mean ± SD of 391.4 ± 23.7 to 424.7 ± 28.4 m (P<.05). Discussion After dry needling combined with therapeutic exercises, patients who had chronic pain following TKA showed clinically significant improvements in pain, range of motion, function, and myofascial trigger points. Future randomized clinical trials should further investigate the effectiveness of this protocol under similar conditions. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2017;47(3):209-216. Epub 3 Feb 2017. doi:10.2519/jospt.2017.7089.

Outcome Assessment in Total Knee Arthroplasty: A Systematic Review and Critical Appraisal

BACKGROUND

The Outcome Measures in Rheumatology (OMERACT) initiative developed a core outcome set (COS) of domains to assess effectiveness of interventions for knee osteoarthritis. These domains (pain, physical function, patient global assessment, imaging at 1 year) should be assessed in every trial to make research evidence meaningful and comparable. We systematically evaluated and critically appraised the use of measurement instruments and outcome domains in prospective studies evaluating patients with knee osteoarthritis undergoing total knee arthroplasty (TKA) and assessed their accordance with the OMERACT COS.

METHODS

Literature search was performed until August 26, 2014, in Medline and Embase. Clinical trials and prospective observational studies with ≥50 participants and a follow-up of ≥1 year were included. We collected general study characteristics, comprehensive information on measurement instruments, and corresponding domains used.

RESULTS

This systematic review identified low accordance of used outcome domains with the OMERACT COS of domains published in 1997. Only 4 of 100 included studies included all recommended core domains. Pain (85% of studies) and physical function (86%) were assessed frequently, whereas patient global assessment (21%) and joint imaging (≥1 year; 27%) were rarely assessed. There was substantial heterogeneity in the use of measurement instruments (n = 111) investigating TKA.

CONCLUSION

More efforts are required to implement the existing COS. In addition, a more consistent use of adequate measurement instruments is important to make research evidence on TKA more relevant, better comparable, and thus more useful for guideline developers and clinical decision makers.

A systematic review of the outcomes reported in trials of medication review in older patients: the need for a core outcome set

AIM

Medication review has been advocated as one of the measures to tackle the challenge of polypharmacy in older patients, yet there is no consensus on how best to evaluate its efficacy. This study aimed to assess outcome reporting in trials of medication review in older patients.

METHODS

Randomized controlled trials (RCTs), prospective studies and RCT protocols involving medication review performed in patients aged 65 years or older in any setting of care were identified from: (1) a recent systematic review; (2) RCT registries of ongoing studies; (3) the Cochrane library. The type, definition, and frequency of all outcomes reported were extracted independently by two researchers.

RESULTS

Forty-seven RCTs or prospective published studies and 32 RCT protocols were identified. A total of 327 distinct outcomes were identified in the 47 published studies. Only one fifth (21%) of the studies evaluated the impact of medication reviews on adverse events such as drug reactions or drug-related hospital admissions. Most of the outcomes were related to medication use (n = 114, 35%) and healthcare use (n = 74, 23%). Very few outcomes were patient-related (n = 24, 7%). A total of 248 distinct outcomes were identified in the 32 RCT protocols. Overall, the number of outcomes and the number and type of health domains covered by the outcomes varied largely.

CONCLUSION

Outcome reporting from RCTs concerning medication review in older patients is heterogeneous. This review highlights the need for a standardized core outcome set for medication review in older patients, to improve outcome reporting and evidence synthesis.

Psychological Traits in Patients Waiting for Total Knee Arthroplasty. A Cross-sectional Study

BACKGROUND

To determine the prevalence of psychiatric distress in an Australian patient population waiting for total knee arthroplasty and to assess the associations between psychological distress and other baseline characteristics.

METHODS

This is a cross-sectional study of prospectively collected data from patients with knee arthritis participating in the New South Wales Osteoarthritis Chronic Care Program. Participants were divided into 2 groups based on the Depression Anxiety and Stress Score. The prevalence of psychological distress was compared to reported prevalence in the Australian community. Between-group comparisons of a number of variables were made, including demographic and socioeconomic data, health and psychiatric data, patient-reported knee and quality-of-life scores, and measured function.

RESULTS

Data from 3103 patients were available and 2809 patients were eligible for inclusion, with 1740 (62%) females. Mean patient age was 68 years, and mean body mass index was 33.8. We found 753 (26.8%, standard deviation: 0.44) of participants reported psychological distress. Those reporting distress were more likely to be female (P = .025), younger (66.6 vs 68.8 years, P < .001), with a higher body mass index (34.5 vs 32.7, P < .001), and had more comorbidities (3.4 vs 2.8, P < .001). The distressed group had significantly worse knee pain (visual analog scale: 7.1 vs 6.2, P < .001; Knee Injury and Osteoarthritis Score pain component: 28.9 vs 41.2, P < .001), knee function, and general quality-of-health scores (P < .001).

CONCLUSION

Psychological health is an important and often overlooked predictor of severity of symptoms and dysfunction in patients with knee arthritis. As it can affect the outcome for surgery, psychological health should be better assessed and treated before surgery to help reduce preoperative dysfunction and improve postoperative outcomes of total knee arthroplasty.

Improving patients’ experience and outcome of total joint replacement: the RESTORE programme

Background

Total hip replacements (THRs) and total knee replacements (TKRs) are common elective procedures. In the REsearch STudies into the ORthopaedic Experience (RESTORE) programme, we explored the care and experiences of patients with osteoarthritis after being listed for THR and TKR up to the time when an optimal outcome should be expected.

Objective

To undertake a programme of research studies to work towards improving patient outcomes after THR and TKR.

Methods

We used methodologies appropriate to research questions: systematic reviews, qualitative studies, randomised controlled trials (RCTs), feasibility studies, cohort studies and a survey. Research was supported by patient and public involvement.

Results

Systematic review of longitudinal studies showed that moderate to severe long-term pain affects about 7–23% of patients after THR and 10–34% after TKR. In our cohort study, 10% of patients with hip replacement and 30% with knee replacement showed no clinically or statistically significant functional improvement. In our review of pain assessment few research studies used measures to capture the incidence, character and impact of long-term pain. Qualitative studies highlighted the importance of support by health and social professionals for patients at different stages of the joint replacement pathway. Our review of longitudinal studies suggested that patients with poorer psychological health, physical function or pain before surgery had poorer long-term outcomes and may benefit from pre-surgical interventions. However, uptake of a pre-operative pain management intervention was low. Although evidence relating to patient outcomes was limited, comorbidities are common and may lead to an increased risk of adverse events, suggesting the possible value of optimising pre-operative management. The evidence base on clinical effectiveness of pre-surgical interventions, occupational therapy and physiotherapy-based rehabilitation relied on small RCTs but suggested short-term benefit. Our feasibility studies showed that definitive trials of occupational therapy before surgery and post-discharge group-based physiotherapy exercise are feasible and acceptable to patients. Randomised trial results and systematic review suggest that patients with THR should receive local anaesthetic infiltration for the management of long-term pain, but in patients receiving TKR it may not provide additional benefit to femoral nerve block. From a NHS and Personal Social Services perspective, local anaesthetic infiltration was a cost-effective treatment in primary THR. In qualitative interviews, patients and health-care professionals recognised the importance of participating in the RCTs. To support future interventions and their evaluation, we conducted a study comparing outcome measures and analysed the RCTs as cohort studies. Analyses highlighted the importance of different methods in treating and assessing hip and knee osteoarthritis. There was an inverse association between radiographic severity of osteoarthritis and pain and function in patients waiting for TKR but no association in THR. Different pain characteristics predicted long-term pain in THR and TKR. Outcomes after joint replacement should be assessed with a patient-reported outcome and a functional test.

Conclusions

The RESTORE programme provides important information to guide the development of interventions to improve long-term outcomes for patients with osteoarthritis receiving THR and TKR. Issues relating to their evaluation and the assessment of patient outcomes are highlighted. Potential interventions at key times in the patient pathway were identified and deserve further study, ultimately in the context of a complex intervention.

Study registration

Current Controlled Trials ISRCTN52305381.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 12. See the NIHR Journals Library website for further project information.

Variability in conditioned pain modulation predicts response to NSAID treatment in patients with knee osteoarthritis

Background

Patients with painful knee osteoarthritis (OA) demonstrate hyperalgesia and altered pain-modulatory responses. While some prior work has demonstrated cross-sectional associations between laboratory and clinical pain measures, it is unknown whether individual variability in quantitative sensory testing (QST) responses at baseline can prospectively predict analgesic treatment responses.

Method

Patients with knee OA (n = 35) were compared on QST responses to a demographically-matched pain-free control group (n = 39), after which patients completed a month-long treatment study of diclofenac sodium topical gel (1 %), applied up to 4 times daily.

Results

OA patients demonstrated reduced pain thresholds at multiple anatomic sites, as well as reduced conditioned pain modulation (CPM) and enhanced temporal summation of pain. The most pain-sensitive patients tended to report the most intense and neuropathic OA pain. Following diclofenac treatment, the knee OA cohort showed a roughly 30 % improvement in pain, regardless of the presence or absence of neuropathic symptoms. Baseline CPM scores, an index of endogenous pain-inhibitory capacity, were prospectively associated with treatment-related changes in clinical pain. Specifically, participants with higher CPM at baseline (i.e., better functioning endogenous pain-inhibitory systems) showed more reduction in pain at the end of treatment (p < .05).

Conclusions

These results support prior findings of amplified pain sensitivity and reduced pain-inhibition in OA patients. Moreover, the moderate to strong associations between laboratory-based measures of pain sensitivity and indices of clinical pain highlight the clinical relevance of QST in this sample. Finally, the prospective association between CPM and diclofenac response suggests that QST-based phenotyping may have utility in explaining inter-patient variability in long-term analgesic treatment outcomes.

Trial registration

ClinicalTrials.Gov Identifier: NCT01383954. Registered June 22, 2011.

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.

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.

Persistent pain is common 1-2 years after shoulder replacement

BACKGROUND AND PURPOSE

Persistent postsurgical pain is a well-recognized problem after various types of surgery such as amputation and thoracotomy. The prevalence of persistent pain, and the extent to which it involves neuropathic pain, is highly dependent on the type of surgery. We investigated the prevalence of, characteristics of, and risk factors for persistent pain 1-2 years after shoulder replacement.

PATIENTS AND METHODS

A questionnaire was sent to patients who underwent primary shoulder replacement between April 2011 and April 2012, and whose data were recorded in the Danish Shoulder Arthroplasty Register. Patients who had undergone reoperation or bilateral replacements were excluded. Persistent pain was defined as constant or daily pain within the last month, which interfered much or very much with daily activities. Multivariate logistic regression was used to assess risk factors.

RESULTS

538 patients were available for analysis. The prevalence of persistent pain was 22% (CI: 18-25), and the prevalence of presumed neuropathic pain was 13% (CI: 10-16). Persistent pain was more frequent in fracture patients (29%) than in osteoarthritis patients (16%), while the prevalence of neuropathic pain was similar. Severe pain during the first postoperative week increased the risk of persistent pain. Risk also increased with hemiprosthesis (as compared to total prosthesis) in osteoarthritis patients, and with previous osteosynthesis and pain elsewhere in fracture patients.

INTERPRETATION

Persistent pain after shoulder replacement is a daily burden for many patients. Further studies should address patient and prosthesis selection, postoperative pain management, and follow-up of these patients.

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

A small proportion of patients have persistent pain after total knee replacement (TKR). The primary aim of this study was to record the prevalence of pain after TKR at specific intervals post-operatively and to ascertain the impact of neuropathic pain. The secondary aim was to establish any predictive factors that could be used to identify patients who were likely to have high levels of pain or neuropathic pain after TKR. A total of 96 patients were included in the study. Their mean age was 71 years (48 to 89); 54 (56%) were female. The mean follow-up was 46 months (39 to 51). Pre-operative demographic details were recorded including a Visual Analogue Score (VAS) for pain, the Hospital Anxiety and Depression score as well as the painDETECT score for neuropathic pain. Functional outcome was assessed using the Oxford Knee score. The mean pre-operative VAS was 5.8 (1 to 10); and it improved significantly at all time periods post-operatively (p < 0.001): (from 4.5 at day three to five (1 to 10), 3.2 at six weeks (0 to 9), 2.4 at three months (0 to 7), 2.0 at six months (0 to 9), 1.7 at nine months (0 to 9), 1.5 at one year (0 to 8) and 2.0 at mean 46 months (0 to 10)). There was a high correlation (r > 0.7; p < 0.001) between the mean VAS scores for pain and the mean painDETECT scores at three months, one year and three years post-operatively. There was no correlation between the pre-operative scores and any post-operative scores at any time point. We report the prevalence of pain and neuropathic pain at various intervals up to three years after TKR. Neuropathic pain is an underestimated problem in patients with pain after TKR. It peaks at between six weeks and three-months post-operatively. However, from these data we were unable to predict which patients are most likely to be affected.

Assessment of chronic post-surgical pain after knee replacement: development of a core outcome set

Background

Approximately 20% of patients experience chronic post-surgical pain (CPSP) after total knee replacement (TKR). There is scope to improve assessment of CPSP after TKR, and this study aimed to develop a core outcome set.

Methods

Eighty patients and 43 clinicians were recruited into a three-round modified Delphi study. In Round 1, participants were presented with 56 pain features identified from a systematic review, structured interviews with patients and focus groups with clinicians. Participants assigned importance ratings, using a 1–9 scale, to individual pain features; those features rated as most important were retained in subsequent rounds. Consensus that a pain feature should be included in the core outcome set was defined as the feature having a rating of 7–9 by ≥70% of both panels (patients and clinicians) and 1–3 by ≤15% of both panels or rated as 7–9 by ≥90% of one panel.

Results

Round 1 was completed by 71 patients and 39 clinicians, and Round 3 by 62 patients and 33 clinicians. The final consensus was that 33 pain features were important. These were grouped into an 8-item core outcome set comprising: pain intensity, pain interference with daily living, pain and physical functioning, temporal aspects of pain, pain description, emotional aspects of pain, use of pain medication, and improvement and satisfaction with pain relief.

Conclusions

This core outcome set serves to guide assessment of CPSP after TKR. Consistency in assessment can promote standardized reporting and facilitate comparability between studies that address a common but understudied type of CPSP.