Neuropathic pain in the IMI-APPROACH knee osteoarthritis cohort: prevalence and phenotyping

ObjectivesOsteoarthritis (OA) patients with a neuropathic pain (NP) component may represent a specific phenotype. This study compares joint damage, pain and functional disability between knee OA patients with a likely NP component, and those without a likely NP component.MethodsBaseline data from the Innovative Medicines Initiative Applied Public-Private Research enabling OsteoArthritis Clinical Headway knee OA cohort study were used. Patients with a painDETECT score ≥19 (with likely NP component, n=24) were matched on a 1:2 ratio to patients with a painDETECT score ≤12 (without likely NP component), and similar knee and general pain (Knee Injury and Osteoarthritis Outcome Score pain and Short Form 36 pain). Pain, physical function and radiographic joint damage of multiple joints were determined and compared between OA patients with and without a likely NP component.ResultsOA patients with painDETECT scores ≥19 had statistically significant less radiographic joint damage (p≤0.04 for Knee Images Digital Analysis parameters and Kellgren and Lawrence grade), but an impaired physical function (p<0.003 for all tests) compared with patients with a painDETECT score ≤12. In addition, more severe pain was found in joints other than the index knee (p≤0.001 for hips and hands), while joint damage throughout the body was not different.ConclusionsOA patients with a likely NP component, as determined with the painDETECT questionnaire, may represent a specific OA phenotype, where local and overall joint damage is not the main cause of pain and disability. Patients with this NP component will likely not benefit from general pain medication and/or disease-modifying OA drug (DMOAD) therapy. Reserved inclusion of these patients in DMOAD trials is advised in the quest for successful OA treatments.Trial registration numberThe study is registered under clinicaltrials.gov nr: NCT03883568.

Factors Associated with Intermittent, Constant, and Mixed Pain in People with Knee Osteoarthritis

Purpose: To explore factors associated with intermittent, constant, and mixed pain in people with knee osteoarthritis. Method: We conducted a secondary analysis of a cross-sectional multicenter study with adults ≥ 40 years with knee osteoarthritis. Participants completed questionnaires on personal (e.g., demographics, comorbidities), physical (e.g., physical function), psychological (e.g., depressive symptoms), pain (e.g., qualities), and tests for physical performance and nervous system sensitivity. We qualified patients’ pain as intermittent, constant, or mixed using the Modified painDETECT Questionnaire and assessed associations with the variables using multinomial logistic regression. Results: The 279 participants had an average age of 63.8 years (SD = 9.6), BMI of 31.5 kg/m2 (SD = 8.7), and 58.6% were female. Older age (odds ratio [OR] 0.95; 95% CI: 0.90, 1.00) and higher self-reported physical function ([OR] 0.94; 95% CI: 0.91, 0.98) were associated with a lower likelihood of mixed pain compared with intermittent pain. Higher pain intensity ([OR] 1.25; 95% CI: 1.07, 1.47) was related to a 25% higher likelihood of mixed pain compared with intermittent pain. Conclusions: This study provides initial data for associations of personal, pain, and physical function factors with different pain patterns. Awareness of these factors can help clinicians develop targeted strategies for managing patients’ pain.

Prevalence of Neuropathic Pain Varies in Patients With Knee Osteoarthritis in Different Treatment Stages

Background: Pain is the main symptom of knee osteoarthritis (KOA) and can be classified as nociceptive pain and neuropathic pain (NP). However, the prevalence and risk factors of NP in patients with KOA at different treatment stages vary in countries and are still unclear in China.Methods: Patients in this retrospective study were divided into three groups according to treatment stage, including outpatient stage, preoperative total knee arthroplasty (pre-TKA) stage and postoperative 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) grades, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were analyzed.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 (WOMAC>10; OR=4.88, 95% CI: 2.38-10.01, p<0.001) scores 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.Discussion: Different prevalence of NP occur in KOA patients at different treatment stages. Due to the low prevalence of NP in the outpatient and post-TKA groups, we suggest not regularly screening for NP in these patients, while it may be essential to screen for NP in patients waiting for TKA. In the latter group, higher NRS and WOMAC pain scores are important risk factors of NP.

Microsurgical decompression of the supraorbital nerve in the treatment of chronic neuropathic pain in the frontal-temporal area

Chronic headache is common. One of the causes of frontal-temporal pain may be compression of sensory nerves from the trigeminal nerve system, for example, the supraorbital nerve. Our study involved 12 women with symptoms of supraorbital nerve neuralgia resistant to drug correction. He underwent microsurgical decompression of the supraorbital nerve. The results of the operation were assessed by the change in the level of neuropathic pain using the PainDetect questionnaire and the degree of psychosocial maladjustment of the patient according to the MIDAS questionnaire, before and after the operation. The data obtained indicate a significant decrease in the level of neuropathic pain in patients 1 month after surgery and a significant minimization of the effect of headache on the quality of life in patients 3 months after surgery. Two out of 12 women did not notice any improvement, which required repeated delayed revision and extended proximal decompression of the supraorbital nerve with dissection of m. corrugator supercilii fibers. After the myotomy, pain regression was achieved and the patients noted that they were satisfied with the result.

Nonoperative treatment of recalcitrant neuritis of the infrapatellar saphenous nerve: a case series

Background Neuritis of the infrapatellar branch of the saphenous nerve can result from iatrogenic injury, entrapment, bursitis, or patellar dislocation. Currently, there is an unmet clinical need for treating refractory neuritis nonsurgically. Case presentation Three patients presented with persistent anterior knee pain caused by neuritis of the infrapatellar branch of the saphenous nerve that had got excellent but only temporary relief from steroid and local anesthetic nerve block. The neuropathic pain diagnostic Douleur Neuropathique 4 questionnaire and painDETECT questionnaire confirmed presence of neuropathic pain. After injection with 25 mg amniotic and umbilical cord particulate, the patient’s pain decreased from 7.3 before injection to 0.3 at 6 weeks postinjection. In addition, neuropathic symptoms significantly improved at 2 weeks and were not present by 6 weeks. By 63 weeks, two of the patients reported continued complete pain relief, while one patient underwent total knee replacement due to an allergy of a previously implanted unicondylar implant. Conclusions This case series suggests that amniotic and umbilical cord particulate may be a viable alternative to reduce pain in patients with neuropathic pain.

Prospective observational study to examine health-related quality of life and develop models to predict long-term patient-reported outcomes 6 months after hospital discharge with blunt thoracic injuries

ObjectiveThis study aimed to examine the long-term outcomes and health-related quality of life in patients with blunt thoracic injuries over 6 months from hospital discharge and develop models to predict long-term patient-reported outcomes.DesignA prospective observational study using longitudinal survey design.SettingThe study recruitment was undertaken at 12 UK hospitals which represented diverse geographical locations and covered urban, suburban and rural areas across England and Wales.Participants337 patients admitted to hospital with blunt thoracic injuries were recruited between June 2018–October 2020.MethodsParticipants completed a bank of two quality of life surveys (Short Form-12 (SF-12) and EuroQol 5-Dimensions 5-Levels) and two pain questionnaires (Brief Pain Inventory and painDETECT Questionnaire) at four time points over the first 6 months after discharge from hospital. A total of 211 (63%) participants completed the outcomes data at 6 months after hospital discharge.Outcomes measuresThree outcomes were measured using pre-existing and validated patient-reported outcome measures. Outcomes included: Poor physical function (SF-12 Physical Component Score); chronic pain (Brief Pain Inventory Pain Severity Score); and neuropathic pain (painDETECT Questionnaire).ResultsDespite a trend towards improving physical functional and pain at 6 months, outcomes did not return to participants perceived baseline level of function. At 6 months after hospital discharge, 37% (n=77) of participants reported poor physical function; 36.5% (n=77) reported a chronic pain state; and 22% (n=47) reported pain with a neuropathic component. Predictive models were developed for each outcome highlighting important data collection requirements for predicting long-term outcomes in this population. Model diagnostics including calibration and discrimination statistics suggested good model fit in this development cohort.ConclusionsThis study identified the recovery trajectories for patients with blunt thoracic injuries over the first 6 months after hospital discharge and present prognostic models for three important outcomes which after external validation could be used as clinical risk stratification scores.

Preoperative use of the modified radiofrequency neuroablation of the genicular and cutaneous nerves of the knee joint for alleviating postoperative pain after arthroplasty

The aim of the study. To improve the effectiveness of pain syndrome management in the postoperative period in patients after knee arthroplasty with radiofrequency neuroablation (RFNA). Materials and methods. A prospective, open, randomized study on the treatment result analysis of 93 patients with knee joint osteoarthritis of the III–IV stage was conducted. Patients were divided into two groups: the study group (n = 44) and the comparison group (n = 49). The study group patients underwent arthroplasty of one knee and RFNA of the genicular and cutaneous nerves in the preoperative period. The comparison group patients underwent only knee arthroplasty. Assessment of pain intensity, functional status and quality of life of patients was performed using the VAS, WOMAC, KOOS questionnaires before treatment, 1.5, 3 and 6 months after surgery, taking into account the overall quality of life according to the SF-36 questionnaire and the possibility of developing neuropathic pain component according to the PainDetect questionnaire. Results. The result analysis obtained with the VAS showed pain reduction in both groups in 6 months after total knee arthroplasty (TKA), in the study group – 2 (2; 2) points, in the comparison group – 3 (2; 3) points. The results assessed with the WOMAC questionnaire showed greater improvement in treatment outcomes among patients who underwent knee arthroplasty in combination with RFNA – 32 (28; 34) points after 6 months. In the comparison group, there was also an improvement in functional status on examination in 1.5 months after surgery, but with less effective reduction of pain and physical recovery, which was seen on the examination in 6 months – 33.0 (28.5; 37.0) points. The analysis using the KOOS questionnaire showed a positive increase in postoperative indicators in both groups of patients, and it was 41.88 (37.20; 44.79) points in the comparison group and 47.67 (40.63; 50.51) points in the study group during a 6-month follow-up after arthroplasty. The SF-36 result analysis in 6 months after surgical treatment showed nearly identical restore of the psychological component of health in both patient groups – 56.63 (55.83; 59.03) points in the comparison group and 58.96 (54.24, 60.35) points – in the study group. The study group demonstrated better restoration of the physical component of health. The neuropathic component of pain was not detected among the examined groups of patients using the PainDetect questionnaire. Conclusions. RFNA of the genicular nerves and additional ablation of cutaneous nerves reduces the intensity of pain in the postoperative period after knee replacement and allows patients more quickly and easier restore functional activity and improve quality of life.